Exact calculation of three-body contact interaction to second order

International Nuclear Information System (INIS)

Kaiser, N.

2012-01-01

For a system of fermions with a three-body contact interaction the second-order contributions to the energy per particle anti E(k f ) are calculated exactly. The three-particle scattering amplitude in the medium is derived in closed analytical form from the corresponding two-loop rescattering diagram. We compare the (genuine) second-order three-body contribution to anti E(k f )∝k f 10 with the second-order term due to the density-dependent effective two-body interaction, and find that the latter term dominates. The results of the present study are of interest for nuclear many-body calculations where chiral three-nucleon forces are treated beyond leading order via a density-dependent effective two-body interaction. (orig.)

Two-body potentials in the collective model

International Nuclear Information System (INIS)

Draayer, J.P.; Rosensteel, G.; Arizona State Univ., Tempe

1982-01-01

The question, 'How well can a 1+2-body shell-model interaction represent a many-body potential.', is addressed by optimally expanding the (1+2+3)-body potential β 3 cos 3γ and the (1+2+3+4)-body potential β 4 of the Bohr-Mottelson collective model in terms of (1+2)-body operators. It is found that the correlation of β 4 with its approximation is greater than 97% throughout the sd shell. Although β 3 cos 3γ is also well approximated in the first half of the sd shell where it has more than 80% correlation with its approximation, the correlation drops abruptly at 28 Si to 50% and remains low in the second half of the shell. The approximations are primarily sums of the various components of the quadrupole-quadrupole interaction connecting different major oscillator shells. The results suggest that axially-symmetric deformation can be represented by simple (1+2)-body operators, whereas asymmetric shapes require non-simple 3-body terms. (orig.)

Chain and ladder models with two-body interactions and analytical ground states

Science.gov (United States)

Manna, Sourav; Nielsen, Anne E. B.

2018-05-01

We consider a family of spin-1 /2 models with few-body, SU(2)-invariant Hamiltonians and analytical ground states related to the one-dimensional (1D) Haldane-Shastry wave function. The spins are placed on the surface of a cylinder, and the standard 1D Haldane-Shastry model is obtained by placing the spins with equal spacing in a circle around the cylinder. Here, we show that another interesting family of models with two-body exchange interactions is obtained if we instead place the spins along one or two lines parallel to the cylinder axis, giving rise to chain and ladder models, respectively. We can change the scale along the cylinder axis without changing the radius of the cylinder. This gives us a parameter that controls the ratio between the circumference of the cylinder and all other length scales in the system. We use Monte Carlo simulations and analytical investigations to study how this ratio affects the properties of the models. If the ratio is large, we find that the two legs of the ladder decouple into two chains that are in a critical phase with Haldane-Shastry-like properties. If the ratio is small, the wave function reduces to a product of singlets. In between, we find that the behavior of the correlations and the Renyi entropy depends on the distance considered. For small distances the behavior is critical, and for long distances the correlations decay exponentially and the entropy shows an area law behavior. The distance up to which there is critical behavior gets larger as the ratio increases.

Crossover dynamics of dispersive shocks in Bose-Einstein condensates characterized by two- and three-body interactions

KAUST Repository

Crosta, M.; Trillo, S.; Fratalocchi, Andrea

2012-01-01

We show that the perturbative nonlinearity associated with three-atom interactions, competing with standard two-body repulsive interactions, can change dramatically the evolution of one-dimensional (1D) dispersive shock waves in a Bose-Einstein condensate. In particular, we prove the existence of a rich crossover dynamics, ranging from the formation of multiple shocks regularized by nonlinear oscillations culminating in coexisting dark and antidark matter waves to 1D-soliton collapse. For a given scattering length, all these different regimes can be accessed by varying the density of atoms in the condensate.

Crossover dynamics of dispersive shocks in Bose-Einstein condensates characterized by two- and three-body interactions

KAUST Repository

Crosta, M.

2012-04-10

We show that the perturbative nonlinearity associated with three-atom interactions, competing with standard two-body repulsive interactions, can change dramatically the evolution of one-dimensional (1D) dispersive shock waves in a Bose-Einstein condensate. In particular, we prove the existence of a rich crossover dynamics, ranging from the formation of multiple shocks regularized by nonlinear oscillations culminating in coexisting dark and antidark matter waves to 1D-soliton collapse. For a given scattering length, all these different regimes can be accessed by varying the density of atoms in the condensate.

Two-body quantum mechanical problem on spheres

OpenAIRE

Shchepetilov, Alexey V.

2005-01-01

The quantum mechanical two-body problem with a central interaction on the sphere ${\\bf S}^{n}$ is considered. Using recent results in representation theory an ordinary differential equation for some energy levels is found. For several interactive potentials these energy levels are calculated in explicit form.

Hubbard-Stratonovich-like Transformations for Few-Body Inter-actions

Directory of Open Access Journals (Sweden)

Körber Christopher

2018-01-01

Full Text Available Through the development of many-body methodology and algorithms, it has become possible to describe quantum systems composed of a large number of particles with great accuracy. Essential to all these methods is the application of auxiliary fields via the Hubbard-Stratonovich transformation. This transformation effectively reduces two-body interactions to interactions of one particle with the auxiliary field, thereby improving the computational scaling of the respective algorithms. The relevance of collective phenomena and interactions grows with the number of particles. For many theories, e.g. Chiral Perturbation Theory, the inclusion of three-body forces has become essential in order to further increase the accuracy on the many-body level. In this proceeding, the an-alytical framework for establishing a Hubbard-Stratonovich-like transformation, which allows for the systematic and controlled inclusion of contact three-and more-body inter-actions, is presented.

Relativistic two-body forces in many-body systems

International Nuclear Information System (INIS)

Namyslowski, J.M.

1979-01-01

For the fully off-shell extension in the relativistic dynamics, based on a covariant light-front field theory, we define the relative momenta and their proper angular variables such that -1 < cos theta/sub α/ < 1. In terms of these variables and the timelike total momenta we write explicitly the Weinberg interaction, corresponding to the exchange of a spinless particle of mass μ. The total momentum dependence and the cluster decomposition property of the Weinberg interaction are presented in detail, together with its energy dependence and other nonlocal features. In the nonrelativistic limit we recover the Yukawa interaction, while for the finite masses the Weinberg interaction is a product of the Yukawa interaction and a form factor. The Weinberg two-body force goes to zero at large energies and is truly nonlocal, in spite of the fact that the underlying field theory has a local Lagrangian

Generalized separable expansion method of the two-body and the three-body scattering amplitudes

International Nuclear Information System (INIS)

Oryu, S.; Ishihara, T.

1976-01-01

A systematic method is proposed for obtaining new N-rank separable amplitudes of the two-body and the three-body equations. First of all, the authors start from the Amado equation which is modified from the three-body Faddeev equation by using the two-body Yamaguchi potential for the nucleon-nucleon interaction. It is well known that the Amado equation can be integrated on the real axis because the kernel has a logarithmic cut on the real axis. However, a separable three-body form factor which is regular on the real axis except for the cut has been found. (Auth.)

Towards a two-body neuroscience

OpenAIRE

Dumas, Guillaume

2011-01-01

Recent work from our interdisciplinary research group has revealed the emergence of inter-brain synchronization across multiple frequency bands during social interaction.1 Our findings result from the close collaboration between experts who study neural dynamics and developmental psychology. The initial aim of the collaboration was to combine knowledge from these two fields in order to move from a classical one-brain neuroscience towards a novel two-body approach. A new technique called hyper...

Polarization phenomena in two body systems

International Nuclear Information System (INIS)

Thomas, G.H.

1978-01-01

A review is given of strong interactions at very low, low, intermediate, and high energies over the range 6.14 MeV to 150 GeV/c with regard to polarization phenomena in two-body systems. From the one-pion-exchange model to the theory that can possibly relate to all the phenomena, namely, quantum electrodynamics the review pointed to a unified explanation for the interactions under study. 46 references

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

Science.gov (United States)

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

2017-05-01

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

Sampling general N-body interactions with auxiliary fields

Science.gov (United States)

Körber, C.; Berkowitz, E.; Luu, T.

2017-09-01

We present a general auxiliary field transformation which generates effective interactions containing all possible N-body contact terms. The strength of the induced terms can analytically be described in terms of general coefficients associated with the transformation and thus are controllable. This transformation provides a novel way for sampling 3- and 4-body (and higher) contact interactions non-perturbatively in lattice quantum Monte Carlo simulations. As a proof of principle, we show that our method reproduces the exact solution for a two-site quantum mechanical problem.

Algebraic diagrammatic construction formalism with three-body interactions

Science.gov (United States)

Raimondi, Francesco; Barbieri, Carlo

2018-05-01

Background: Self-consistent Green's function theory has recently been extended to the basic formalism needed to account for three-body interactions [Carbone, Cipollone, Barbieri, Rios, and Polls, Phys. Rev. C 88, 054326 (2013), 10.1103/PhysRevC.88.054326]. The contribution of three-nucleon forces has so far been included in ab initio calculations on nuclear matter and finite nuclei only as averaged two-nucleon forces. Purpose: We derive the working equations for all possible two- and three-nucleon terms that enter the expansion of the self-energy up to the third order, thus including the interaction-irreducible (i.e., not averaged) diagrams with three-nucleon forces that have been previously neglected. Methods: We employ the algebraic diagrammatic construction up to the third order as an organization scheme for generating a nonperturbative self-energy, in which ring (particle-hole) and ladder (particle-particle) diagrams are resummed to all orders. Results: We derive expressions of the static and dynamic self-energy up to the third order, by taking into account the set of diagrams required when either the skeleton or nonskeleton expansions of the single-particle propagator are assumed. A hierarchy of importance among different diagrams is revealed, and a particular emphasis is given to a third-order diagram [see Fig. 2(c)] that is expected to play a significant role among those featuring an interaction-irreducible three-nucleon force. Conclusion: A consistent formalism to resum at infinite order correlations induced by three-nucleon forces in the self-consistent Green's function theory is now available and ready to be implemented in the many-body solvers.

One-dimensional reduction of the three-dimenstional Gross-Pitaevskii equation with two- and three-body interactions

International Nuclear Information System (INIS)

Cardoso, W. B.; Avelar, A. T.; Bazeia, D.

2011-01-01

We deal with the three-dimensional Gross-Pitaevskii equation which is used to describe a cloud of dilute bosonic atoms that interact under competing two- and three-body scattering potentials. We study the case where the cloud of atoms is strongly confined in two spatial dimensions, allowing us to build an unidimensional nonlinear equation,controlled by the nonlinearities and the confining potentials that trap the system along the longitudinal coordinate. We focus attention on specific limits dictated by the cubic and quintic coefficients, and we implement numerical simulations to help us to quantify the validity of the procedure.

Short versus long range interactions and the size of two-body weakly bound objects

International Nuclear Information System (INIS)

Lombard, R.J.; Volpe, C.

2003-01-01

Very weakly bound systems may manifest intriguing ''universal'' properties, independent of the specific interaction which keeps the system bound. An interesting example is given by relations between the size of the system and the separation energy, or scaling laws. So far, scaling laws have been investigated for short-range and long-range (repulsive) potentials. We report here on scaling laws for weakly bound two-body systems valid for a larger class of potentials, i.e. short-range potentials having a repulsive core and long-range attractive potentials. We emphasize analogies and differences between the short- and the long-range case. In particular, we show that the emergence of halos is a threshold phenomenon which can arise when the system is bound not only by short-range interactions but also by long-range ones, and this for any value of the orbital angular momentum l. These results enlarge the image of halo systems we are accustomed to. (orig.)

Three-body interactions in sociophysics and their role in coalition forming

Science.gov (United States)

Naumis, Gerardo G.; Samaniego-Steta, F.; del Castillo-Mussot, M.; Vázquez, G. J.

2007-06-01

An study of the effects of three-body interactions in the process of coalition formation is presented. In particular, we modify a spin glass model of bimodal propensities and also a Potts model in order to include a particular three-body Hamiltonian that reproduces the main features of the required interactions. The model can be used to study conflicts, political struggles, political parties, social networks, wars and organizational structures. As an application, we analyze a simplified model of the Iraq war.

The Casimir interaction of a massive vector field between concentric spherical bodies

International Nuclear Information System (INIS)

Teo, L.P.

2011-01-01

The Casimir interaction energy due to the vacuum fluctuations of a massive vector field between two perfectly conducting concentric spherical bodies is computed. The TE contribution to the Casimir interaction energy is a direct generalization of the massless case but the TM contribution is much more complicated. Each TM mode is a linear combination of a transverse mode which is the generalization of a TM mode in the massless case and a longitudinal mode that does not appear in the massless case. In contrast to the case of two parallel perfectly conducting plates, there are no TM discrete modes that vanish identically in the perfectly conducting spherical bodies. Numerical simulations show that the Casimir interaction force between the two bodies is always attractive.

Core Problem: Does the CV Parent Body Magnetization require differentiation?

Science.gov (United States)

O'Brien, T.; Tarduno, J. A.; Smirnov, A. V.

2016-12-01

Evidence for the presence of past dynamos from magnetic studies of meteorites can provide key information on the nature and evolution of parent bodies. However, the suggestion of a past core dynamo for the CV parent body based on the study of the Allende meteorite has led to a paradox: a core dynamo requires differentiation, evidence for which is missing in the meteorite record. The key parameter used to distinguish core dynamo versus external field mechanisms is absolute field paleointensity, with high values (>>1 μT) favoring the former. Here we explore the fundamental requirements for absolute field intensity measurement in the Allende meteorite: single domain grains that are non-interacting. Magnetic hysteresis and directional data define strong magnetic interactions, negating a standard interpretation of paleointensity measurements in terms of absolute paleofield values. The Allende low field magnetic susceptibility is dominated by magnetite and FeNi grains, whereas the magnetic remanence is carried by an iron sulfide whose remanence-carrying capacity increases with laboratory cycling at constant field values, indicating reordering. The iron sulfide and FeNi grains are in close proximity, providing mineralogical context for interactions. We interpret the magnetization of Allende to record the intense early solar wind with metal-sulfide interactions amplifying the field, giving the false impression of a higher field value in some prior studies. An undifferentiated CV parent body is thus compatible with Allende's magnetization. Early solar wind magnetization should be the null hypothesis for evaluating the source of magnetization for chondrites and other meteorites.

Three-body interactions and the Landau levels using Nikiforov ...

Indian Academy of Sciences (India)

In this article, the eigenvalues for the three-body interactions on the line and the Landau levels in the presence of topological defects have been regenerated by the Nikiforov–Uvarov (NU) method. Two exhaustive lists of such exactly solvable potentials are given. Keywords. Nikiforov–Uvarov (NU) method; three-body ...

Comparison of permutationally invariant polynomials, neural networks, and Gaussian approximation potentials in representing water interactions through many-body expansions

Science.gov (United States)

Nguyen, Thuong T.; Székely, Eszter; Imbalzano, Giulio; Behler, Jörg; Csányi, Gábor; Ceriotti, Michele; Götz, Andreas W.; Paesani, Francesco

2018-06-01

The accurate representation of multidimensional potential energy surfaces is a necessary requirement for realistic computer simulations of molecular systems. The continued increase in computer power accompanied by advances in correlated electronic structure methods nowadays enables routine calculations of accurate interaction energies for small systems, which can then be used as references for the development of analytical potential energy functions (PEFs) rigorously derived from many-body (MB) expansions. Building on the accuracy of the MB-pol many-body PEF, we investigate here the performance of permutationally invariant polynomials (PIPs), neural networks, and Gaussian approximation potentials (GAPs) in representing water two-body and three-body interaction energies, denoting the resulting potentials PIP-MB-pol, Behler-Parrinello neural network-MB-pol, and GAP-MB-pol, respectively. Our analysis shows that all three analytical representations exhibit similar levels of accuracy in reproducing both two-body and three-body reference data as well as interaction energies of small water clusters obtained from calculations carried out at the coupled cluster level of theory, the current gold standard for chemical accuracy. These results demonstrate the synergy between interatomic potentials formulated in terms of a many-body expansion, such as MB-pol, that are physically sound and transferable, and machine-learning techniques that provide a flexible framework to approximate the short-range interaction energy terms.

Three-body interactions in many-body effective field theory

International Nuclear Information System (INIS)

Furnstahl, R.J.

2004-01-01

This contribution is an advertisement for applying effective field theory (EFT) to many-body problems, including nuclei and cold atomic gases. Examples involving three-body interactions are used to illustrate how EFT's quantify and systematically eliminate model dependence, and how they make many-body calculations simpler and more powerful

Effects of three-body interactions in the parametric and modulational instabilities of Bose–Einstein condensates

International Nuclear Information System (INIS)

Wamba, Etienne; Mohamadou, Alidou; Ekogo, Thierry B.; Atangana, Jacque; Kofane, Timoleon C.

2011-01-01

The parametric modulational instability for a discrete nonlinear Schrödinger equation with a cubic–quintic nonlinearity is analyzed. This model describes the dynamics of BECs, with both two- and three-body interatomic interactions trapped in an optical lattice. We identify and discuss the salient features of the three-body interaction in the parametric modulational instability. It is shown that the three-body interaction term can both, shift as well as narrow the window of parametric instability, and also change the behavior of a modulationally stable and parametrically unstable BEC with attractive two-body interaction. We explore this instability through the multiple-scale analysis and identify it numerically. The effect of the three body losses have also been investigated. -- Highlights: ► The parametric MI for the 1D GPE with a cubic–quintic nonlinearity is analyzed. ► The two- and three-body recombination and time-dependent scattering length is considered. ► We generate bright matter waves soliton through MI.

Simulations of collisions between N-body classical systems in interaction

International Nuclear Information System (INIS)

Morisseau, Francois

2006-05-01

The Classical N-body Dynamics (CNBD) is dedicated to the simulation of collisions between classical systems. The 2-body interaction used here has the properties of the Van der Waals potential and depends on just a few parameters. This work has two main goals. First, some theoretical approaches assume that the dynamical stage of the collisions plays an important role. Moreover, colliding nuclei are supposed to present a 1. order liquid-gas phase transition. Several signals have been introduced to show this transition. We have searched for two of them: the bimodality of the mass asymmetry and negative heat capacity. We have found them and we give an explanation of their presence in our calculations. Second, we have improved the interaction by adding a Coulomb like potential and by taking into account the stronger proton-neutron interaction in nuclei. Then we have figured out the relations that exist between the parameters of the 2-body interaction and the properties of the systems. These studies allow us to fit the properties of the classical systems to those of the nuclei. In this manuscript the first results of this fit are shown. (author)

CCHCR1 interacts with EDC4, suggesting its localization in P-bodies

Energy Technology Data Exchange (ETDEWEB)

Ling, Y.H.; Wong, C.C. [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Li, K.W. [Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, 1081 HV Amsterdam (Netherlands); Chan, K.M. [School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China); Boukamp, P. [Division of Genetics of Skin Carcinogenesis, A110 German Cancer Research Center, Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); Liu, W.K., E-mail: ken-liu@cuhk.edu.hk [School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong (China)

2014-09-10

Coiled‐coil alpha‐helical rod protein 1 (CCHCR1) is suggested as a candidate biomarker for psoriasis for more than a decade but its function remains poorly understood because of the inconsistent findings in the literature. CCHCR1 protein is suggested to be localized in the cytoplasm, nucleus, mitochondria, or centrosome and to regulate various cellular functions, including steroidogenesis, proliferation, differentiation, and cytoskeleton organization. In this study, we attempted to find a consensus between these findings by identifying the interaction partners of CCHCR1 using co-immunoprecipiation with a stable cell line expressing EGFP-tagged CCHCR1. Out of more than 100 co-immunoprecipitants identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), the enhancer of mRNA-decapping protein 4 (EDC4), which is a processing body (P-body) component, was particularly found to be the major interacting partner of CCHCR1. Confocal imaging confirmed the localization of CCHCR1 in P-bodies and its N-terminus is required for this subcellular localization, suggesting that CCHCR1 is a novel P-body component. As P-bodies are the site for mRNA metabolism, our findings provide a molecular basis for the function of CCHCR1, any disruption of which may affect the transcriptome of the cell, and causing abnormal cell functions. - Highlights: • We identified CCHCR1 as a novel P-body component. • We identified EDC4 as the major interacting partner of CCHCR1. • N-terminus of CCHCR1 protein is required for its P-bodies localization.

Micromagnetic simulation of two-body magnetic nanoparticles

Science.gov (United States)

Li, Fei; Lu, Jincheng; Yang, Yu; Lu, Xiaofeng; Tang, Rujun; Sun, Z. Z.

2017-05-01

Field-induced magnetization dynamics was investigated in a system of two magnetic nanoparticles with uniaxial anisotropies and magnetostatic interaction. By using the micromagnetic simulation, ultralow switching field strength was found when the separation distance between the two particles reaches a critical small value on nanometer scale in the perpendicular configuration where the anisotropic axes of the two particles are perpendicular to the separation line. The switching field increases sharply when the separation is away from the critical distance. The same results were observed when varying the radius of particles. The micromagnetic results are consistent with the previous theoretical prediction where dipolar interaction between two single-domain magnetic particles was considered. Our present simulations offered further proofs and possibilities for the low-power applications of information storage as the two-body magnetic nanoparticles could be implemented as a composite information bit.

Two-body hypercharge-exchange reactions in K-p and π+p interactions at 10 and 16 GeV/c

International Nuclear Information System (INIS)

Girtler, P.; Otter, G.; Sliwa, K.; Barnham, K.W.J.; Eason, R.M.; Newham, P.; Pollock, B.; Wells, J.; Mandl, F.; Markytan, M.

1979-01-01

Cross section values or upper limits are presented for twenty-five two-body hypercharge-exchange reactions in K - p and π + p interactions at 10 and 16 GeV/c. The 16 GeV/c results are compared with some predictions of line-reversal plus exchange-degenerate Regge poles, of SU(3) and of the additive quark model. Agreement is found in all cases. (author)

Four-body interaction energy for compressed solid krypton from quantum theory.

Science.gov (United States)

Tian, Chunling; Wu, Na; Liu, Fusheng; Saxena, Surendra K; Zheng, Xingrong

2012-07-28

The importance of the four-body contribution in compressed solid krypton was first evaluated using the many-body expansion method and the coupled cluster theory with full single and double excitations plus perturbative treatment of triples. All different four-atom clusters existing in the first- and second-nearest neighbor shells of face-centered cubic krypton were considered, and both self-consistent-field Hartree-Fock and correlation parts of the four-body interaction were accurately determined from the ambient conditions up to eightfold volume compression. We find that the four-body interaction energy is negative at compression ratio lower than 2, where the dispersive forces play a dominant role. With increasing the compression, the four-body contribution becomes repulsive and significantly cancels the over-softening effects of the three-body potential. The obtained equation of state (EOS) was compared with the experiments and the density-functional theory calculations. It shows that combination of the four-body effects with two- and three-body interactions leads to an excellent agreement with EOS measurements throughout the whole experimental range 0-130 GPa, and extends the prediction to 300 GPa.

Vortex matter stabilized by many-body interactions

Science.gov (United States)

Wolf, S.; Vagov, A.; Shanenko, A. A.; Axt, V. M.; Aguiar, J. Albino

2017-10-01

This work investigates interactions of vortices in superconducting materials between standard types I and II, in the domain of the so-called intertype (IT) superconductivity. Contrary to common expectations, the many-body (many-vortex) contribution is not a correction to the pair-vortex interaction here but plays a crucial role in the formation of the IT vortex matter. In particular, the many-body interactions stabilize vortex clusters that otherwise could not exist. Furthermore, clusters with large numbers of vortices become more stable when approaching the boundary between the intertype domain and type I. This indicates that IT superconductors develop a peculiar unconventional type of the vortex matter governed by the many-body interactions of vortices.

Comparison of electromagnetically induced transparency schemes in semiconductor quantum dot structures: Impact of many-body interactions

DEFF Research Database (Denmark)

Houmark-Nielsen, Jakob; Nielsen, Torben Roland; Mørk, Jesper

2009-01-01

an important impact on the slow light properties. In the case of the Lambda and V schemes, the minimum required coupling power to achieve slow light is significantly reduced by many-body interactions. V type schemes are found to be generally preferable due to a favorable redistribution of carriers in energy......We investigate the impact of many-body interactions on group-velocity slowdown achieved via electromagnetically induced transparency in quantum dots using three different coupling-probe schemes (ladder, V, and Lambda, respectively). We find that for all schemes many-body interactions have...

Whole body interaction with public displays

CERN Document Server

Walter, Robert

2017-01-01

This book develops valuable new approaches to digital out-of-home media and digital signage in urban environments. It offers solutions for communicating interactive features of digital signage to passers-by. Digital out-of-home media and digital signage screens are becoming increasingly interactive thanks to touch input technology and gesture recognition. To optimize their conversion rate, interactive public displays must 1) attract attention, 2) communicate to passers-by that they are interactive, 3) explain the interaction, and 4) provide a motivation for passers-by to interact. This book highlights solutions to problems 2 and 3 above. The focus is on whole-body interaction, where the positions and orientations of users and their individual body parts are captured by specialized sensors (e.g., depth cameras). The book presents revealing findings from a field study on communicating interactivity, a laboratory on analysing visual attention, a field study on mid-air gestures, and a field study on using mid-air...

Three-body interactions and the Landau levels using Nikiforov

Indian Academy of Sciences (India)

In this article, the eigenvalues for the three-body interactions on the line and the Landau levels in the presence of topological defects have been regenerated by the Nikiforov–Uvarov (NU) method. Two exhaustive lists of such exactly solvable potentials are given.

A comprehensive treatment of electromagnetic interactions and the three-body spectator equations

Energy Technology Data Exchange (ETDEWEB)

Jiri Adam; Jay Van Orden

2004-10-01

We present a general derivation the three-body spectator (Gross) equations and the corresponding electromagnetic currents. As in previous paper on two-body systems, the wave equations and currents are derived from those for Bethe-Salpeter equation with the help of algebraic method using a concise matrix notation. The three-body interactions and currents introduced by the transition to the spectator approach are isolated and the matrix elements of the e.m. current are presented in detail for system of three indistinguishable particles, namely for elastic scattering and for two and three body break-up. The general expressions are reduced to the one-boson-exchange approximation to make contact with previous work. The method is general in that it does not rely on introduction of the electromagnetic interaction with the help of the minimal replacement. It would therefore work also for other external fields.

Investigations of the structure and electromagnetic interactions of few-body systems

International Nuclear Information System (INIS)

Lehman, D.R.

1991-07-01

In order to make it easy for the reader to see the specific research carried out and the progress make, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the GWU theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been carry out the continuum part of the theoretical work exactly, this is, by means of exact three- and four-body dynamics. When structure questions are the issue, exact calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art few-body calculations that will serve as an unambiguous means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

Statistical methods for including two-body forces in large system calculations

International Nuclear Information System (INIS)

Grimes, S.M.

1980-07-01

Large systems of interacting particles are often treated by assuming that the effect on any one particle of the remaining N-1 may be approximated by an average potential. This approach reduces the problem to that of finding the bound-state solutions for a particle in a potential; statistical mechanics is then used to obtain the properties of the many-body system. In some physical systems this approach may not be acceptable, because the two-body force component cannot be treated in this one-body limit. A technique for incorporating two-body forces in such calculations in a more realistic fashion is described. 1 figure

Effect of three-body interactions on the zero-temperature equation of state of HCP solid 4He

Science.gov (United States)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-03-01

Previous studies have pointed to the importance of three-body interactions in high density 4He solids. However the computational cost often makes it unfeasible to incorporate these interactions into the simulation of large systems. We report the implementation and evaluation of a computationally efficient perturbative treatment of three-body interactions in hexagonal close packed solid 4He utilizing the recently developed nonadditive three-body potential of Cencek et al. This study represents the first application of the Cencek three-body potential to condensed phase 4He systems. Ground state energies from quantum Monte Carlo simulations, with either fully incorporated or perturbatively treated three-body interactions, are calculated in systems with molar volumes ranging from 21.3 cm3/mol down to 2.5 cm3/mol. These energies are used to derive the zero-temperature equation of state for comparison against existing experimental and theoretical data. The equations of state derived from both perturbative and fully incorporated three-body interactions are found to be in very good agreement with one another, and reproduce the experimental pressure-volume data with significantly better accuracy than is obtained when only two-body interactions are considered. At molar volumes below approximately 4.0 cm3/mol, neither two-body nor three-body equations of state are able to accurately reproduce the experimental pressure-volume data, suggesting that below this molar volume four-body and higher many-body interactions are becoming important.

Phenomenological two-nucleon interaction operator

International Nuclear Information System (INIS)

Lagaris, I.E.; Pandharipande, V.R.

1981-01-01

We report a phenomenological two-nucleon interaction operator obtained by fitting the nucleon-nucleon phase shifts up to 425 MeV in S, P, D and F waves, and the deuteron properties. The operator has the standard eight potentials associated with the two-body operators 1, sigma 1 x sigma 2 , tau 1 x tau 2 , sigma 1 x sigma 2 tau 1 x tau 2 , S 12 , S 12 tau 1 x tau 2 , L x S and L x Stau 2 ; and six phenomenological potentials associated with operators L 2 , L 2 sigma 1 x sigma 2 , L 2 tau 1 x tau 2 , L 2 sigma 1 x sigma 2 tau 1 xtau 2 (L x S) 2 tau 1 x tau 2 . The six quadratic L terms are relatively weak, and are chosen in order to make many-body calculations with this operator simpler. (orig.)

Two- and quasi-two-body strange particle final state production in π+p interactions at low to intermediate energies

International Nuclear Information System (INIS)

Hanson, P.

1982-10-01

The two and quasi-two body final states Σ + K + , Σ + K* (892) + , Σ*(1385) + K + , Σ(1385) + K*(892) + produced by neutral strangeness exchange in π + p interactions are studied using our own 1-3 GeV/c data, comprising the 14 incident momenta of a two million picture bubble chamber experiment, in combination with the world data on the same and related channels. Because low energy resonance formation is not strongly coupled to the Σ,Σ* production channels, at very modest incident momenta their dominant features are seen to be understandable in terms of high energy hypercharge exchange phenomenology. We find that Regge models fitted to data in the 10 to 20 GeV/c range adequately describe the Σ and Σ* channels down to within a few hundred MeV/c of threshold and out to large center of mass scattering angles, and that over the range of the available world data weak exchange degeneracy expectations for these reactions are at least qualitatively successful. We observe that the SU(2), SU(3) flavor symmetries successfully describe these hypercharge exchange processes and relate them to charge exchange via sum rules and equalities expressing flavor independence of the strong interaction; in particular, we derive and test on the available world data a mass broken SU(3) sum rule for π + p → K + Σ + , π - p → K 0 Λ, K - p → anti K 0 n and test over a wider range of momenta than before an earlier expression relating Σ* and Δ production. We also find at least qualitative agreement between quark model predictions for forward hypercharge exchange and the data, and we find that 90 0 hypercharge exchange cross sections also conform to the expectations of the quark constituent picture for hadrons

The self-consistent field model for Fermi systems with account of three-body interactions

Directory of Open Access Journals (Sweden)

Yu.M. Poluektov

2015-12-01

Full Text Available On the basis of a microscopic model of self-consistent field, the thermodynamics of the many-particle Fermi system at finite temperatures with account of three-body interactions is built and the quasiparticle equations of motion are obtained. It is shown that the delta-like three-body interaction gives no contribution into the self-consistent field, and the description of three-body forces requires their nonlocality to be taken into account. The spatially uniform system is considered in detail, and on the basis of the developed microscopic approach general formulas are derived for the fermion's effective mass and the system's equation of state with account of contribution from three-body forces. The effective mass and pressure are numerically calculated for the potential of "semi-transparent sphere" type at zero temperature. Expansions of the effective mass and pressure in powers of density are obtained. It is shown that, with account of only pair forces, the interaction of repulsive character reduces the quasiparticle effective mass relative to the mass of a free particle, and the attractive interaction raises the effective mass. The question of thermodynamic stability of the Fermi system is considered and the three-body repulsive interaction is shown to extend the region of stability of the system with the interparticle pair attraction. The quasiparticle energy spectrum is calculated with account of three-body forces.

Efimov Physics and the Three-Body Parameter within a Two-Channel Framework

DEFF Research Database (Denmark)

Sørensen, Peder Klokmose; V. Fedorov, D.; S. Jensen, A.

2012-01-01

scaling laws. We recover known results for broad Feshbach resonances with small effective range, whereas in the case of narrow resonances we find a distinct non-monotonic behavior of the threshold at which the lowest Efimov trimer merges with the three-body continuum. To address the issue of the physical...... origin of the three-body parameter we provide a physically clear model for the relation between three-body physics and typical two-body atom-atom interactions. Our results demonstrate that experimental information from narrow Feshbach resonances and/or mixed systems are of vital importance to pin down...... the relation of two- and three-body physics in atomic systems....

Parallel Vortex Body Interaction Enabled by Active Flow Control

Science.gov (United States)

Weingaertner, Andre; Tewes, Philipp; Little, Jesse

2017-11-01

An experimental study was conducted to explore the flow physics of parallel vortex body interaction between two NACA 0012 airfoils. Experiments were carried out at chord Reynolds numbers of 740,000. Initially, the leading airfoil was characterized without the target one being installed. Results are in good agreement with thin airfoil theory and data provided in the literature. Afterward, the leading airfoil was fixed at 18° incidence and the target airfoil was installed 6 chord lengths downstream. Plasma actuation (ns-DBD), originating close to the leading edge, was used to control vortex shedding from the leading airfoil at various frequencies (0.04 governing parameters of this vortex body interaction are explored. This work was supported by the Army Research Office under ARO Grant No. W911NF-14-1-0662.

Coulomb two-body problem with internal structure

International Nuclear Information System (INIS)

Kuperin, Yu.A.; Makarov, K.A.; Mel'nikov, Yu.B.

1988-01-01

The methods of the theory of extensions to an enlarged Hilbert space are used to construct a model of the interaction of the external (Coulomb) and internal (quark) channels in the two-body problem. The mutual influence of the spectra of the corresponding channel Hamiltonians is studied: it leads, in particular, to a rearrangement of the spectra of hadronic atoms. An explicit representation is obtained for the S matrix, and its singularities on the energy shell are studied

Off-shell effects and consistency of many-body treatments of dense matter

International Nuclear Information System (INIS)

Krippa, Boris; Birse, Michael C.; McGovern, Judith A.; Walet, Niels R.

2003-01-01

Effective field theory requires all observables to be independent of the representation used for the quantum field operators. It means that off-shell properties of the interactions should not lead to any observable effects. We analyze this issue in the context of many-body approaches to nuclear matter, where it should be possible to shift the contributions of lowest order in purely off-shell two-body interactions into three-body forces. We show that none of the commonly used truncations of the two-body scattering amplitude such as the ladder, Brueckner-Hartree-Fock, or parquet approximations respect this requirement

Two-body Dirac equations for nucleon-nucleon scattering

International Nuclear Information System (INIS)

Liu Bin; Crater, Horace

2003-01-01

We investigate the nucleon-nucleon interaction by using the meson exchange model and the two-body Dirac equations of constraint dynamics. This approach to the two-body problem has been successfully tested for QED and QCD relativistic bound states. An important question we wish to address is whether or not the two-body nucleon-nucleon scattering problem can be reasonably described in this approach as well. This test involves a number of related problems. First we must reduce our two-body Dirac equations exactly to a Schroedinger-like equation in such a way that allows us to use techniques to solve them already developed for Schroedinger-like systems in nonrelativistic quantum mechanics. Related to this, we present a new derivation of Calogero's variable phase shift differential equation for coupled Schroedinger-like equations. Then we determine if the use of nine meson exchanges in our equations gives a reasonable fit to the experimental scattering phase shifts for n-p scattering. The data involve seven angular momentum states including the singlet states 1 S 0 , 1 P 1 , 1 D 2 and the triplet states 3 P 0 , 3 P 1 , 3 S 1 , 3 D 1 . Two models that we have tested give us a fairly good fit. The parameters obtained by fitting the n-p experimental scattering phase shift give a fairly good prediction for most of the p-p experimental scattering phase shifts examined (for the singlet states 1 S 0 , 1 D 2 and triplet states 3 P 0 , 3 P 1 ). Thus the two-body Dirac equations of constraint dynamics present us with a fit that encourages the exploration of a more realistic model. We outline generalizations of the meson exchange model for invariant potentials that may possibly improve the fit

An analysis of few-body cross sections in pp and πp interactions in terms of the two-component picture

International Nuclear Information System (INIS)

Karimaeki, V.

1975-01-01

The energy behaviour of total cross sections of exclusive channel with one, two or three produced pions has been studied in pp and πp interactions. Two components, interpreted as diffractive and non-diffractive, have been fitted to the cross section data assuming an asymptotic power law dependence in psub(lab) for both. Isotopic spin factors were used as constraints to fit different charge channels simultaneously as well as for determining diffractive cross sections for non-observable few-body channels. The diffractive component for fixed multiplicity is found to decrease as psub(lab)sup(-0.16+-0.04). Results are compared with the predictions of factorization and semilocal factorization hypotheses. Total diffractive cross sections derived by the analysis are 5.1+-0.6 mb in pp and 2.2+-0.3 mb in πp interactions at psub(lab)=10 GeV/c. (author)

Chaos and Integrability in Ideal Body-Fluid Interactions

DEFF Research Database (Denmark)

Pedersen, Johan Rønby

2011-01-01

by generating Poincare sections from numerically obtained solutions. By identifying the chaotic solutions and studying the body and vortex orbits, we obtain a better mechanistic understanding of the causes of chaotic behavior. As is well-known from dynamical system theory, the chaos can often be traced back...... of relative equilibria, their stability, and the qualitatively dierent kinds of motion is studied analytically and numerically. We then perform small parametric perturbations destroying the symmetry or conservation law that makes the system integrable. The emergence of chaos in the system is diagnosed...... contains both regular and chaotic regions, and may be understood from KAM theory. We also discover two separate chaotic regimes in the interaction of a body and one point vortex when the body is either noncircular or has asymmetric internal mass distribution. For one of these chaotic regimes the eect...

Relativistic two-body equation for one Dirac and one Duffin-Kemmer particle

International Nuclear Information System (INIS)

Krolikowski, W.

1983-01-01

A new relativistic two-body wave equation is proposed for one spin-1/2 and one spin-0 or spin-1 particle which, if isolated from each other, are described by the Dirac and the Duffin-Kemmer equation, respectively. For a static mutual interaction this equation splits into two equations: a two-body wave equation for one Dirac and one Klein-Gordon particle (which was introduced by the author previously) and a new two-body wave equation for one Dirac and one Proca particle. The proposed equation may be applied in particular to the quark-diquark system. In Appendix, however, an alternative approach is sketched, where the diquark is described as the point limit of a very close Breit system rather than a Duffin-Kemmer particle. (Author)

Observation of the Borromean Three-Body Förster Resonances for Three Interacting Rb Rydberg Atoms.

Science.gov (United States)

Tretyakov, D B; Beterov, I I; Yakshina, E A; Entin, V M; Ryabtsev, I I; Cheinet, P; Pillet, P

2017-10-27

Three-body Förster resonances at long-range interactions of Rydberg atoms were first predicted and observed in Cs Rydberg atoms by Faoro et al. [Nat. Commun. 6, 8173 (2015)NCAOBW2041-172310.1038/ncomms9173]. In these resonances, one of the atoms carries away an energy excess preventing the two-body resonance, leading thus to a Borromean type of Förster energy transfer. But they were in fact observed as the average signal for the large number of atoms N≫1. In this Letter, we report on the first experimental observation of the three-body Förster resonances 3×nP_{3/2}(|M|)→nS_{1/2}+(n+1)S_{1/2}+nP_{3/2}(|M^{*}|) in a few Rb Rydberg atoms with n=36, 37. We have found here clear evidence that there is no signature of the three-body Förster resonance for exactly two interacting Rydberg atoms, while it is present for N=3-5 atoms. This demonstrates the assumption that three-body resonances can generalize to any Rydberg atom. As such resonance represents an effective three-body operator, it can be used to directly control the three-body interactions in quantum simulations and quantum information processing with Rydberg atoms.

LMKB/MARF1 localizes to mRNA processing bodies, interacts with Ge-1, and regulates IFI44L gene expression.

Directory of Open Access Journals (Sweden)

Donald B Bloch

Full Text Available The mRNA processing body (P-body is a cellular structure that regulates the stability of cytoplasmic mRNA. MARF1 is a murine oocyte RNA-binding protein that is associated with maintenance of mRNA homeostasis and genomic stability. In this study, autoantibodies were used to identify Limkain B (LMKB, the human orthologue of MARF1, as a P-body component. Indirect immunofluorescence demonstrated that Ge-1 (a central component of the mammalian core-decapping complex co-localized with LMKB in P-bodies. Two-hybrid and co-immunoprecipitation assays were used to demonstrate interaction between Ge-1 and LMKB. The C-terminal 120 amino acids of LMKB mediated interaction with Ge-1 and the N-terminal 1094 amino acids of Ge-1 were required for interaction with LMKB. LMKB is the first protein identified to date that interacts with this portion of Ge-1. LMKB was expressed in human B and T lymphocyte cell lines; depletion of LMKB increased expression of IFI44L, a gene that has been implicated in the cellular response to Type I interferons. The interaction between LMKB/MARF1, a protein that contains RNA-binding domains, and Ge-1, which interacts with core-decapping proteins, suggests that LMKB has a role in the regulation of mRNA stability. LMKB appears to have different functions in different cell types: maintenance of genomic stability in developing oocytes and possible dampening of the inflammatory response in B and T cells.

Effective two-body equations for the four-body problem with exact treatment of (2+2)-subsystem contributions

International Nuclear Information System (INIS)

Haberzettl, H.; Sandhas, W.

1981-01-01

Effective two-body equations for the four-body problem are derived within the general N-body theory of Alt, Grassberger, and Sandhas. In contrast to usual treatments, the final expressions do not require separable (2+2) subamplitudes but incorporate these exactly. All four-body amplitudes can be calculated from the solution of a single integral equation for the reaction (3+1)→(3+1). With single-term separable approximations for the two-particle and the (3+1) subsystem amplitudes the driving terms of the final equations are seen to reduce to those of the field-theoretical model by Fonseca and Shanley. Since our results are based on an exact and complete N-body theory, the investigation of subsystem reaction mechanisms is facilitated. As a consequence, we are led to a three-particle propagator which has the right pole behavior and includes exchange effects

Folding model analysis of Λ binding energies and three-body ΛNN force

International Nuclear Information System (INIS)

Mian, M.; Rahman Khan, M.Z.

1988-02-01

Working within the framework of the folding model, we analyze the Λ binding energy data of light hypernuclei with effective two-body ΛN plus three-body ΛNN interaction. The two-body density for the core nucleus required for evaluating the three-body force contribution is obtained in terms of the centre of mass pair correlation. It is found that except for Λ 5 He the data are fairly well explained. The three-body force seems to account for the density dependence of the effective two-body ΛN interaction proposed earlier. (author). 13 refs, 2 tabs

Interaction between an ADCY3 Genetic Variant and Two Weight-Lowering Diets Affecting Body Fatness and Body Composition Outcomes Depending on Macronutrient Distribution: A Randomized Trial

Directory of Open Access Journals (Sweden)

Leticia Goni

2018-06-01

Full Text Available The adenylate cyclase 3 (ADCY3 gene is involved in the regulation of several metabolic processes including the development and function of adipose tissue. The effects of the ADCY3 rs10182181 genetic variant on changes in body composition depending on the macronutrient distribution intake after 16 weeks of the dietary intervention were tested. The ADCY3 genetic variant was genotyped in 147 overweight or obese subjects, who were randomly assigned to one of the two diets varying in macronutrient content: a moderately-high-protein diet and a low-fat diet. Anthropometric and body composition measurements (DEXA scan were recorded. Significant interactions between the ADCY3 genotype and dietary intervention on changes in weight, waist circumference, and body composition were found after adjustment for covariates. Thus, in the moderately-high-protein diet group, the G allele was associated with a lower decrease of fat mass, trunk and android fat, and a greater decrease in lean mass. Conversely, in the low-fat diet group carrying the G allele was associated with a greater decrease in trunk, android, gynoid, and visceral fat. Subjects carrying the G allele of the rs10182181 polymorphism may benefit more in terms of weight loss and improvement of body composition measurements when undertaking a hypocaloric low-fat diet as compared to a moderately-high-protein diet.

Simulations of collisions between N-body classical systems in interaction; Simulations de collisions entre systemes classiques a n-corps en interaction

Energy Technology Data Exchange (ETDEWEB)

Morisseau, Francois [Laboratoire de Physique Corpusculaire de CAEN, ENSICAEN, Universite de Caen Basse-Normandie, UFR des Sciences, 6 bd Marechal Juin, 14050 Caen Cedex (France)

2006-05-15

The Classical N-body Dynamics (CNBD) is dedicated to the simulation of collisions between classical systems. The 2-body interaction used here has the properties of the Van der Waals potential and depends on just a few parameters. This work has two main goals. First, some theoretical approaches assume that the dynamical stage of the collisions plays an important role. Moreover, colliding nuclei are supposed to present a 1. order liquid-gas phase transition. Several signals have been introduced to show this transition. We have searched for two of them: the bimodality of the mass asymmetry and negative heat capacity. We have found them and we give an explanation of their presence in our calculations. Second, we have improved the interaction by adding a Coulomb like potential and by taking into account the stronger proton-neutron interaction in nuclei. Then we have figured out the relations that exist between the parameters of the 2-body interaction and the properties of the systems. These studies allow us to fit the properties of the classical systems to those of the nuclei. In this manuscript the first results of this fit are shown. (author)

Highly Enhanced Many-Body Interactions in Anisotropic 2D Semiconductors.

Science.gov (United States)

Sharma, Ankur; Yan, Han; Zhang, Linglong; Sun, Xueqian; Liu, Boqing; Lu, Yuerui

2018-05-15

Atomically thin two-dimensional (2D) semiconductors have presented a plethora of opportunities for future optoelectronic devices and photonics applications, made possible by the strong light matter interactions at the 2D quantum limit. Many body interactions between fundamental particles in 2D semiconductors are strongly enhanced compared with those in bulk semiconductors because of the reduced dimensionality and, thus, reduced dielectric screening. These enhanced many body interactions lead to the formation of robust quasi-particles, such as excitons, trions, and biexcitons, which are extremely important for the optoelectronics device applications of 2D semiconductors, such as light emitting diodes, lasers, and optical modulators, etc. Recently, the emerging anisotropic 2D semiconductors, such as black phosphorus (termed as phosphorene) and phosphorene-like 2D materials, such as ReSe 2 , 2D-perovskites, SnS, etc., show strong anisotropic optical and electrical properties, which are different from conventional isotropic 2D semiconductors, such as transition metal dichalcogenide (TMD) monolayers. This anisotropy leads to the formation of quasi-one-dimensional (quasi-1D) excitons and trions in a 2D system, which results in even stronger many body interactions in anisotropic 2D materials, arising from the further reduced dimensionality of the quasi-particles and thus reduced dielectric screening. Many body interactions have been heavily investigated in TMD monolayers in past years, but not in anisotropic 2D materials yet. The quasi-particles in anisotropic 2D materials have fractional dimensionality which makes them perfect candidates to serve as a platform to study fundamental particle interactions in fractional dimensional space. In this Account, we present our recent progress related to 2D phosphorene, a 2D system with quasi-1D excitons and trions. Phosphorene, because of its unique anisotropic properties, provides a unique 2D platform for investigating the

Investigations of the structure and electromagnetic interactions of few-body systems

International Nuclear Information System (INIS)

Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.

1992-07-01

In order to make it easy for the reader to see the specific research carried out and the progress made, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the George Washington University (GWU) theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions axe the issue, numerically accurate calculations axe always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art fewbody calculations that wig serve as a means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

Matrix Elements of One- and Two-Body Operators in the Unitary Group Approach (I)-Formalism

Institute of Scientific and Technical Information of China (English)

DAI Lian-Rong; PAN Feng

2001-01-01

The tensor algebraic method is used to derive general one- and two-body operator matrix elements within the Un representations, which are useful in the unitary group approach to the configuration interaction problems of quantum many-body systems.

Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, 1 July 1991--30 June 1994

International Nuclear Information System (INIS)

Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.; Bennhold, C.; Ito, Hiroshi; Pratt, R.K.; Najmeddine, M.; Rakei, A.

1994-07-01

In order to make it easy for the reader to see the specific research carried out and the progress made, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the GW nuclear theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered, including coherent photoproduction of π mesons. When the excitation energy of the target nucleus is low, the aim has been to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions are the issue, numerically accurate calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art few-body calculations that will serve as a means of determining at what point standard nuclear physics requires introduction of relativity and/or quark degrees of freedom in order to understand the phenomena in question. So far, the problems considered were mostly concerned with low- to medium-energy regimes where little evidence was found that requires going beyond the traditional approach

Shock/shock interactions between bodies and wings

Directory of Open Access Journals (Sweden)

Gaoxiang XIANG

2018-02-01

Full Text Available This paper examines the Shock/Shock Interactions (SSI between the body and wing of aircraft in supersonic flows. The body is simplified to a flat wedge and the wing is assumed to be a sharp wing. The theoretical spatial dimension reduction method, which transforms the 3D problem into a 2D one, is used to analyze the SSI between the body and wing. The temperature and pressure behind the Mach stem induced by the wing and body are obtained, and the wave configurations in the corner are determined. Numerical validations are conducted by solving the inviscid Euler equations in 3D with a Non-oscillatory and Non-free-parameters Dissipative (NND finite difference scheme. Good agreements between the theoretical and numerical results are obtained. Additionally, the effects of the wedge angle and sweep angle on wave configurations and flow field are considered numerically and theoretically. The influences of wedge angle are significant, whereas the effects of sweep angle on wave configurations are negligible. This paper provides useful information for the design and thermal protection of aircraft in supersonic and hypersonic flows. Keywords: Body and wing, Flow field, Hypersonic flow, Shock/shock interaction, Wave configurations

Two-body tunnel transitions in a Mn 4 single-molecule magnet

Science.gov (United States)

Wernsdorfer, W.; Bhaduri, S.; Tiron, R.; Hendrickson, D. N.; Christou, G.

2004-05-01

The one-body tunnel picture of single-molecule magnets (SMMs) is not always sufficient to explain the measured tunnel transitions. An improvement to the picture is proposed by including also two-body tunnel transitions such as spin-spin cross-relaxation (SSCR) which are mediated by dipolar and weak superexchange interactions between molecules. A Mn 4 SMM is used as a model system. At certain external fields, SSCRs lead to additional quantum resonances which show up in hysteresis loop measurements as well-defined steps.

A MADS box protein interacts with a mating-type protein and is required for fruiting body development in the homothallic ascomycete Sordaria macrospora.

Science.gov (United States)

Nolting, Nicole; Pöggeler, Stefanie

2006-07-01

MADS box transcription factors control diverse developmental processes in plants, metazoans, and fungi. To analyze the involvement of MADS box proteins in fruiting body development of filamentous ascomycetes, we isolated the mcm1 gene from the homothallic ascomycete Sordaria macrospora, which encodes a putative homologue of the Saccharomyces cerevisiae MADS box protein Mcm1p. Deletion of the S. macrospora mcm1 gene resulted in reduced biomass, increased hyphal branching, and reduced hyphal compartment length during vegetative growth. Furthermore, the S. macrospora Deltamcm1 strain was unable to produce fruiting bodies or ascospores during sexual development. A yeast two-hybrid analysis in conjugation with in vitro analyses demonstrated that the S. macrospora MCM1 protein can interact with the putative transcription factor SMTA-1, encoded by the S. macrospora mating-type locus. These results suggest that the S. macrospora MCM1 protein is involved in the transcriptional regulation of mating-type-specific genes as well as in fruiting body development.

Successive canonical transformation in model two-body electrodynamics

International Nuclear Information System (INIS)

Raha, S.

1978-10-01

The possibility is investigated of bypassing the no interaction theorum of Currie, Jordan and Sudarshan for direct action Lagrangians. Starting with the field theoretic description of a two-body electrodynamic problem, the field variable is solved for in terms of the particle variables, which paves the way to write an action-at-a-distance Hamiltonian for the problem. A suitable transformation is found which uncouples the field and the particle variables in the interaction up to order e 2 . It is shown that this transformation leaves the statement of Newton's 2nd law unchanged which also agrees with the standard results of electrodynamics. This allows for the identification of canonical variables for the proper action-at-a-distance problem. 19 references

Three-body vertices with two-body techniques

International Nuclear Information System (INIS)

Mitra, A.N.; Sharma, V.K.

1976-01-01

It has long been recognized that vertex functions for few particle systems provide a convenient medium for the analysis of reactions in the language of Feynman diagrams, analogously to elementary particle processes. The development of three-particle theory during the last decade has provided considerably more impetus for the use of the language of three-body vertex functions through the possibility of their 'exact' evaluations with only two-body input. While three-body vertices are probably superfluous for the description of only three-body processes (for which exact amplitudes are already available) their practical usefulness often extends to reactions involving more than three-particle systems (for which 'exact' amplitudes are still a distant goal), as long as such systems can be meaningfully described in terms of not more than three particles playing the active role. This paper investigates a simplified construction of three-body vertices. This must check against their standard definition as overlap integral. Unfortunately this definition involves a non-trivial normalization of three-body wave functions with realistic NN potentials, and has little practical scope for extension beyond A=3. (Auth.)

A method for solving a three-body problem with energy-dependent interactions

International Nuclear Information System (INIS)

Safronov, A.N.

1994-01-01

A method is proposed for solving a three-body problem with energy-dependent interactions. This method is based on introducing the dependence of scattering operators and state vectors on an additional external parameter. Effects caused by the energy dependence of the interaction operator are investigated by using the unitary condition for the amplitude of the 2 → 2 and 2 → 3 transitions. It is shown, in particular, that taking this dependence into account leads to a change in the relation between the asymptotic normalization factor of the wave function of the three-body bound state and the vertex constant of virtual dissociation (synthesis) of the system into two fragments. 15 refs

Cavity-QED interactions of two correlated atoms

Science.gov (United States)

Esfandiarpour, Saeideh; Safari, Hassan; Bennett, Robert; Yoshi Buhmann, Stefan

2018-05-01

We consider the resonant van der Waals (vdW) interaction between two correlated identical two-level atoms (at least one of which being excited) within the framework of macroscopic cavity quantum electrodynamics in linear, dispersing and absorbing media. The interaction of both atoms with the body-assisted electromagnetic field of the cavity is assumed to be strong. Our time-independent evaluation is based on an extended Jaynes–Cummings model. For a system prepared in a superposition of its dressed states, we derive the general form of the vdW forces, using a Lorentzian single-mode approximation. We demonstrate the applicability of this approach by considering the case of a planar cavity and showing the position dependence of Rabi oscillations. We also show that in the limiting case of weak coupling, our results reproduce the perturbative ones for the case where the field is initially in vacuum state while the atomic state is in a superposition of two correlated states sharing one excitation.

Many-body interactions in quasi-freestanding graphene

Energy Technology Data Exchange (ETDEWEB)

Siegel, David; Park, Cheol-Hwan; Hwang, Choongyu; Deslippe, Jack; Fedorov, Alexei; Louie, Steven; Lanzara, Alessandra

2011-06-03

The Landau-Fermi liquid picture for quasiparticles assumes that charge carriers are dressed by many-body interactions, forming one of the fundamental theories of solids. Whether this picture still holds for a semimetal such as graphene at the neutrality point, i.e., when the chemical potential coincides with the Dirac point energy, is one of the long-standing puzzles in this field. Here we present such a study in quasi-freestanding graphene by using high-resolution angle-resolved photoemission spectroscopy. We see the electron-electron and electron-phonon interactions go through substantial changes when the semimetallic regime is approached, including renormalizations due to strong electron-electron interactions with similarities to marginal Fermi liquid behavior. These findings set a new benchmark in our understanding of many-body physics in graphene and a variety of novel materials with Dirac fermions.

Moving android: on social robots and body-in-interaction.

Science.gov (United States)

Alac, Morana

2009-08-01

Social robotics studies embodied technologies designed for social interaction. This paper examines the implied idea of embodiment using as data a sequence in which practitioners of social robotics are involved in designing a robot's movement. The moments of learning and work in the laboratory enact the social body as material, dynamic, and multiparty: the body-in-interaction. In describing subject-object reconfigurations, the paper explores how the well-known ideas of extending the body with instruments can be applied to a technology designed to function as our surrogate.

Simulation of aerosol flow interaction with a solid body on molecular level

Science.gov (United States)

Amelyushkin, Ivan A.; Stasenko, Albert L.

2018-05-01

Physico-mathematical models and numerical algorithm of two-phase flow interaction with a solid body are developed. Results of droplet motion and its impingement upon a rough surface in real gas boundary layer simulation on the molecular level obtained via molecular dynamics technique are presented.

Two stage approach to dynamic soil structure interaction

International Nuclear Information System (INIS)

Nelson, I.

1981-01-01

A two stage approach is used to reduce the effective size of soil island required to solve dynamic soil structure interaction problems. The ficticious boundaries of the conventional soil island are chosen sufficiently far from the structure so that the presence of the structure causes only a slight perturbation on the soil response near the boundaries. While the resulting finite element model of the soil structure system can be solved, it requires a formidable computational effort. Currently, a two stage approach is used to reduce this effort. The combined soil structure system has many frequencies and wavelengths. For a stiff structure, the lowest frequencies are those associated with the motion of the structure as a rigid body. In the soil, these modes have the longest wavelengths and attenuate most slowly. The higher frequency deformational modes of the structure have shorter wavelengths and their effect attenuates more rapidly with distance from the structure. The difference in soil response between a computation with a refined structural model, and one with a crude model, tends towards zero a very short distance from the structure. In the current work, the 'crude model' is a rigid structure with the same geometry and inertial properties as the refined model. Preliminary calculations indicated that a rigid structure would be a good low frequency approximation to the actual structure, provided the structure was much stiffer than the native soil. (orig./RW)

Few-body bound states on a three-dimensional and two-dimensional lattice and continuum limit for one-dimensional many-body system

International Nuclear Information System (INIS)

Rudin, S.I.

1984-01-01

The three-body bound states of particles moving on a lattice and interacting with two-body point-like potentials are studied in two dimensions (2D) and three dimensions (3D) for spin 1/2 fermions and spin O bosons (with application to magnons). When a three boson bound state forms in 3D, it does so discontinuously implying a finite size of approximately two lattice constants. This phenomenon does not occur in 2D. For three fermions, interactions are effectively absent in the state S = 3/2. In the state S = 1/2, when there is an interaction, the three particles complex is unstable against breakup into a bound pair S = 0 and a free third particle. A finite density of states for 2D lattice makes this result relevant for BCS theory of superconductivity in 3D in confirming the choice of singlet pair (Cooper pair) as the fundamental entity. Results for bosons allows estimation of the limits of validity of spin wave theory as applied to the anisotropic Heisenberg ferromagnet in 3D with J/sub z/ > J/sub x/ = J/sub y/

Unitary pole approximations and expansions in few-body systems

International Nuclear Information System (INIS)

Casel, A.; Haberzettl, H.; Sandhas, W.

1982-01-01

The unitary pole approximations or expansions of the two-body subsystem operators are well known, and particularly efficient and practical, methods to reduce the three-body problem to an effective two-body theory. In the present investigation we develop generalizations of these approximation techniques to the subsystem amplitudes of problems with higher particle numbers. They are based on the expansion of effective potentials which, in contrast to the genuine two-body interactions, are now energy dependent. Despite this feature our generalizations require only energy independent form factors, thus preserving one of the essential advantages of the genuine two-body approach. The application of these techniques to the four-body case is discussed in detail

[A Concept Analysis for Mind-Body Interaction].

Science.gov (United States)

Chen, Hsing-Wen; Yeh, Mei-Ling; Rong, Jiin-Ru

2015-08-01

Mind-body interaction (MBI) refers the holistic association and interactive process between wisdom, thinking, belief, and physiological reaction, which critically affects health. The main goal of nursing is to maintain mind and body in a healthy state of well being. Few reports in the literatures have addressed the evaluation and application of MBI. Thus, a conceptual analysis of this subject is worth exploring in depth. This paper analyzes the MBI concept step by step based on the procedures of Walker and Avant. The result defines the characteristics of MBI as (1) being aware of psychosomatic effects, (2) interacting between psychology, neurology, immunology and others, and (3) turning out a bio-psycho-social status. Antecedents include geography, culture, race, gender, age, education, profession, values, personality, experience, and health status. Consequences of MBI include well-being, illness, and death. This paper provides new information on MBI that clarifies its meaning, provides comprehensive cognition, and suggests useful applications.

Rigid body formulation in a finite element context with contact interaction

Science.gov (United States)

Refachinho de Campos, Paulo R.; Gay Neto, Alfredo

2018-03-01

The present work proposes a formulation to employ rigid bodies together with flexible bodies in the context of a nonlinear finite element solver, with contact interactions. Inertial contributions due to distribution of mass of a rigid body are fully developed, considering a general pole position associated with a single node, representing a rigid body element. Additionally, a mechanical constraint is proposed to connect a rigid region composed by several nodes, which is useful for linking rigid/flexible bodies in a finite element environment. Rodrigues rotation parameters are used to describe finite rotations, by an updated Lagrangian description. In addition, the contact formulation entitled master-surface to master-surface is employed in conjunction with the rigid body element and flexible bodies, aiming to consider their interaction in a rigid-flexible multibody environment. New surface parameterizations are presented to establish contact pairs, permitting pointwise interaction in a frictional scenario. Numerical examples are provided to show robustness and applicability of the methods.

Two-body and three-body correlations in Os-shell nuclei

International Nuclear Information System (INIS)

Halderson, D.W.

1974-01-01

It is well known that conventional Brueckner calculations with modern nucleon-nucleon potentials have failed to reproduce experimental saturation properties of finite nuclei. The intent was to determine whether the discrepancies are due to the methods of calculation or the nucleon-nucleon potentials. Brueckner procedures which include only two-body correlations were applied to Os-shell nuclei. Calculations were performed with and without the Hartree-Fock condition, with and without partial occupation probabilities, and with various propagators and Pauli correction techniques. Then the entire class of three-body correlations was calculated by matrix solution of the Bethe-Faddeev equations. The convergence necessary to validate this technique was achieved by constructing a set of basic functions which contain no center of mass excitations and yet are still properly antisymmetrized. The two-body calculations yielded typical Brueckner results. The nuclei were underbound or the radii were too small. However, the three-body calculations yielded reasonable radii and moderate overbinding for the Reid soft core and Hamada-Johnston potentials. Therefore, the Bethe-Faddeev formalism has been shown to be a reasonable approach to calculation of the three-body correlations in finite nuclei; and the results of []these calculations demonstrate that the underbinding and collapsed radii of two-body calculations were largely due to the uncalculated correlations. (auth)

Human body micro-environment: The benefits of controlling airflow interaction

DEFF Research Database (Denmark)

Melikov, Arsen Krikor

2015-01-01

This paper focuses on the micro-environment around a human body, and especially on its interaction with the surrounding environment. Research on the free convection flow generated by a human body (including the convective boundary layer around the body and the thermal plume above the body), its...

Integrability and chaos in body-vortex interactions

DEFF Research Database (Denmark)

Pedersen, Johan Rønby; Aref, Hassan

2009-01-01

. The equations of motion may be cast in Hamiltonian form. We analyze the equations of motion using techniques from the theory of dynamical systems. The simplest such system, a single point vortex and a circular body, is integrable. As we add vortices, or change other features of the system such as the body shape......, the motion may become chaotic. Numerical solutions are shown and analyzed with an emphasis on the transition to chaos and its physical meaning. This class of systems provides a rich family of few-degree-of-freedom systems that capture essential fluid-body interaction physics....

Two-body non-leptonic decays on the lattice

CERN Document Server

Ciuchini, M; Martinelli, G; Silvestrini, L

1996-01-01

We show that, under reasonable hypotheses, it is possible to study two-body non-leptonic weak decays in numerical simulations of lattice QCD. By assuming that final-state interactions are dominated by the nearby resonances and that the couplings of the resonances to the final particles are smooth functions of the external momenta, it is possible indeed to overcome the difficulties imposed by the Maiani-Testa no-go theorem and to extract the weak decay amplitudes, including their phases. Under the same assumptions, results can be obtained also for time-like form factors and quasi-elastic processes.

Relativistic two-body system in (1+1)-dimensional QED. 1. On the circle S1

International Nuclear Information System (INIS)

Barut, A.O.; Saradzhev, F.M.

1994-01-01

From the coupled Maxwell-Dirac equations for two fermion fields Ψ 1 , Ψ 2 the authors derive a covariant two-body equation for the composite field Φ(x 1 , x 2 ) in configuration space which includes radiative self-energy effects. Both Coulomb gauge and covariant gauge have been used and their equivalence is proved. For the space S 1 the authors solve the two-body equation with mutual interactions exactly and obtain the mass spectrum in the case of massless fermions. 7 refs., 5 figs

77 FR 31073 - Audit Requirements for Third Party Conformity Assessment Bodies

Science.gov (United States)

2012-05-24

... 1112 and 1118 Audit Requirements for Third Party Conformity Assessment Bodies and Requirements... PRODUCT SAFETY COMMISSION 16 CFR Part 1112 [CPSC Docket No. CPSC-2009-0061] Audit Requirements for Third... rule establishing requirements for the periodic audit of third party conformity assessment bodies as a...

Metastable decoherence-free subspaces and electromagnetically induced transparency in interacting many-body systems

DEFF Research Database (Denmark)

Macieszczak, Katarzyna; Zhou, Yanli; Hofferberth, Sebastian

2017-01-01

to stationarity this leads to a slow dynamics, which renders the typical assumption of fast relaxation invalid. We derive analytically the effective nonequilibrium dynamics in the decoherence-free subspace, which features coherent and dissipative two-body interactions. We discuss the use of this scenario...

The d-α elastic scattering and the lithium-6 in a three-body model with separable interactions

International Nuclear Information System (INIS)

Charnomordic, Brigitte.

1976-01-01

This work consists in a three-body treatment of the six nucleon system. The model is constructed by considering two identical nucleons and a structureless alpha particle. Such a system can be described by the Faddeev-Lovelace equations. A partial antisymetrization is performed taking into account the identity of the nucleons. Pairwise interacting particles with nonlocal separable forces are introduced. Two-body potentials are chosen in each n-n and n-α partial wave. After an analysis of the existing separable interactions, new n-α and 1S0 parametrization are constructed. The sensitivity to the tensor force and the role of the N-α description are especially studied. The case of d-α elastic scattering is also discussed. The observables: differential cross-section, analyzing powers and transfer polarization coefficients are calculated and compared with experiments. The results show the ability of a three-body model with separable interactions in describing the main properties of the d-α elastic scattering and lithium-6 [fr

The relativistic two-body potentials of constraint theory from summation of Feynman diagrams

OpenAIRE

Jallouli, H.; Sazdjian, H.

1996-01-01

The relativistic two-body potentials of constraint theory for systems composed of two spin-0 or two spin-1/2 particles are calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates them to the scattering amplitude. The cases of scalar and vector interactions with massless photons are considered. The two-photon exchange contributions, calculated with covariant propagators,are globally free of spurious infra-red singularities and produce at leading order ...

Accurate first principles calculation of many-body interactions

International Nuclear Information System (INIS)

Tawa, G.J.; Moskowitz, J.W.; Schmidt, K.E.

1991-01-01

This paper reports on the electronic structure Schrodinger equation that is solved for the van der Waals complexes spin-polarized H 2 and H 3 , and the closed-shell systems He 2 and He 3 by Monte Carlo methods. Two types of calculations are performed, variational Monte Carlo, which gives an upper bound to the eigenvalue of the Schrodinger equation, and Green's function Monte Carlo, which can solve the Schrodinger equation exactly within statistical sampling errors. The simulations are carried out on an ETA-10 supercomputer, and already existing computer codes were extensively modified to ensure highly efficient coding. A major component of the computations was the development of highly optimized many-electron wave functions. The results from the variational Monte Carlo simulations are reported for both the two- and three-body interaction energies

Interaction of Two Active Region Filaments Observed by NVST and SDO

Energy Technology Data Exchange (ETDEWEB)

Yang, Liheng; Yan, Xiaoli; Xue, Zhike; Xiang, Yongyuan [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216 (China); Li, Ting, E-mail: yangliheng@ynao.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2017-04-01

Using high spatial and temporal resolution H α data from the New Vacuum Solar Telescope (NVST) and simultaneous observations from the Solar Dynamics Observatory , we present the rare event of the interaction between two filaments (F1 and F2) in AR 11967 on 2014 January 31. The adjacent two filaments were almost perpendicular to each other. Their interaction was driven by the movement of F1 and started when the two filaments collided with each other. During the interaction, the threads of F1 continuously slipped from the northeast to the southwest, and were accompanied by the brightenings at the junction of two filaments and the northeast footpoint of F2. Part of F1 and the main body of F2 became invisible in H α wavelength due to the heating and the motion of F2. At the same time, bright material initiated from the junction of two filaments were observed to move along F1. The magnetic connectivities of F1 were found to be changed after their interaction. These observations suggest that magnetic reconnection was involved in the interaction of two filaments and resulted in the eruption of one filament.

Effects of three-body interactions on the dynamics of entanglement in spin chains

International Nuclear Information System (INIS)

Shi Cuihua; Wu Yinzhong; Li Zhenya

2009-01-01

With the consideration of three-body interaction, dynamics of pairwise entanglement in spin chains is studied. The dependence of pairwise entanglement dynamics on the type of coupling, and distance between the spins is analyzed in a finite chain for different initial states. It is found that, for an Ising chain, three-body interactions are not in favor of preparing entanglement between the nearest neighbor spins, while three-body interactions are favorable for creating entanglement between remote spins from a separable initial state. For an isotropic Heisenberg chain, the pairwise concurrence will decrease when three-body interactions are considered both for a separable initial state and for a maximally entangled initial state, however, three-body interactions will retard the decay of the concurrence in an Ising chain when the initial state takes the maximally entangled state.

[Focus Notified Bodies. New requirements for designation and monitoring].

Science.gov (United States)

Poos, U; Edelhäuser, R

2014-12-01

For medical devices with a higher risk, Notified Bodies assess whether the manufacturers and their products fulfill the requirements laid down in the European directives on medical devices. Notified Bodies are designated through a designation procedure by the designating authority, in Germany by ZLG. The requirements for the designation arise from the respective annexes of the directives on medical devices. Since these are only minimal criteria, different documents have been compiled on a European and national level to concretize these minimal criteria regarding the organization, quality management system, resources, and certification procedure. The rules of the ZLG are thereby the essential documents for designation in Germany. Moreover, according to Implementing Regulation (EU) no. 912/2013, the European commission and the other European designating authorities also have to be involved in the designation process. The aim of continuous monitoring of the Notified Bodies with assessments on the bodies' premises as well as with observed audits is to ensure the permanent fulfillment of the requirements. If nonconformities are found in a body's quality management system or in its implementation of the conformity assessment procedures, the body is obliged to provide ZLG with a corrective actions plan. In the case that the nonconformities are not resolved in time or critical nonconformities are found, ZLG may take actions, e.g., restrict the scope of designation, suspend, or - as last resort - withdraw the designation.

Tidal interaction of black holes and Newtonian viscous bodies

International Nuclear Information System (INIS)

Poisson, Eric

2009-01-01

The tidal interaction of a (rotating or nonrotating) black hole with nearby bodies produces changes in its mass, angular momentum, and surface area. Similarly, tidal forces acting on a Newtonian, viscous body do work on the body, change its angular momentum, and part of the transferred gravitational energy is dissipated into heat. The equations that describe the rate of change of the black-hole mass, angular momentum, and surface area as a result of the tidal interaction are compared with the equations that describe how the tidal forces do work, torque, and produce heat in the Newtonian body. The equations are strikingly similar, and unexpectedly, the correspondence between the Newtonian-body and black-hole results is revealed to hold in near-quantitative detail. The correspondence involves the combination k 2 τ of 'Love quantities' that incorporate the details of the body's internal structure; k 2 is the tidal Love number, and τ is the viscosity-produced delay between the action of the tidal forces and the body's reaction. The combination k 2 τ is of order GM/c 3 for a black hole of mass M; it does not vanish, in spite of the fact that k 2 is known to vanish individually for a nonrotating black hole.

Two-body Dirac equation and its wave function at the origin

International Nuclear Information System (INIS)

Ito, Hitoshi

1998-01-01

We propose a relativistic bound state equation for the Dirac particles interacting through an Abelian gauge field. It reduces to the (one body) Dirac equation in the infinite limit of one of the masses and is invariant under the PCT transformation. This invariance is a consequence of a modification of the Stueckelberg-Feynman boundary condition for propagation of the negative-energy two-body states, by which the some effect of the crossed diagram is taken in the lowest ladder equation. We can correct back the modification in perturbative calculations of the weak-coupling theory by adding a counter correction term in the interaction kernel. The equation can be used for the phenomenology of the heavy flavored mesons. We get good behavior of the wave function at the origin (WFO), with which the annihilation amplitude of the pseudoscalar meson becomes finite. Some comments are mentioned for the application in the heavy quark effective theory. The talk was based on a preprint

Interactive effects of body-size structure and adaptive foraging on food-web stability.

Science.gov (United States)

Heckmann, Lotta; Drossel, Barbara; Brose, Ulrich; Guill, Christian

2012-03-01

Body-size structure of food webs and adaptive foraging of consumers are two of the dominant concepts of our understanding how natural ecosystems maintain their stability and diversity. The interplay of these two processes, however, is a critically important yet unresolved issue. To fill this gap in our knowledge of ecosystem stability, we investigate dynamic random and niche model food webs to evaluate the proportion of persistent species. We show that stronger body-size structures and faster adaptation stabilise these food webs. Body-size structures yield stabilising configurations of interaction strength distributions across food webs, and adaptive foraging emphasises links to resources closer to the base. Moreover, both mechanisms combined have a cumulative effect. Most importantly, unstructured random webs evolve via adaptive foraging into stable size-structured food webs. This offers a mechanistic explanation of how size structure adaptively emerges in complex food webs, thus building a novel bridge between these two important stabilising mechanisms. © 2012 Blackwell Publishing Ltd/CNRS.

Mind-Body Interactions in Anxiety and Somatic Symptoms.

Science.gov (United States)

Mallorquí-Bagué, Núria; Bulbena, Antonio; Pailhez, Guillem; Garfinkel, Sarah N; Critchley, Hugo D

2016-01-01

Anxiety and somatic symptoms have a high prevalence in the general population. A mechanistic understanding of how different factors contribute to the development and maintenance of these symptoms, which are highly associated with anxiety disorders, is crucial to optimize treatments. In this article, we review recent literature on this topic and present a redefined model of mind-body interaction in anxiety and somatic symptoms, with an emphasis on both bottom-up and top-down processes. Consideration is given to the role played in this interaction by predisposing physiological and psychological traits (e.g., interoception, anxiety sensitivity, and trait anxiety) and to the levels at which mindfulness approaches may exert a therapeutic benefit. The proposed model of mind-body interaction in anxiety and somatic symptoms is appraised in the context of joint hypermobility syndrome, a constitutional variant associated with autonomic abnormalities and vulnerability to anxiety disorders.

[Understanding social interaction in children with autism spectrum disorders: does whole-body motion mean anything to them?].

Science.gov (United States)

Centelles, L; Assaiante, C; Etchegoyhen, K; Bouvard, M; Schmitz, C

2012-06-01

Autism spectrum disorders (ASD) are characterized by difficulties in social interaction and verbal and non verbal reciprocal communication. Face and gaze direction, which participate in non verbal communication, are described as atypical in ASD. Also body movements carry multiple social cues. Under certain circumstances, for instance when seeing two persons from far, they constitute the only support that allows the grasping of a social content. Here, we investigated the contribution of whole-body motion processing in social understanding. The aim of the study was to evaluate whether children with ASD make use of information carried by body motion to categorize dynamic visual scenes that portrayed social interactions. In 1973, Johansson devised a technique for studying the perception of biological motion that minimizes static form information from the stimulus, but retains motion information. In these point-light displays, the movement figure, such as a body, is represented by a small number of illuminated dots positioned to highlight the motion of the body parts. We used Johansson's model to explore the ability of children with ASD to understand social interactions based on human movement analysis. Three-second silent point-light displays were created by videotaping two actors. The two actors were either interacting together or moving side by side without interacting. A large range of social interaction displays were used to cover social scenes depicting social norms (conventional gestures and courteous attitudes), emotional situations (carrying positive or negative valences) and scenes from games (sports, dance, etc.). Children were asked to carefully watch the stimuli and to classify them according to the question "Are the two persons communicating or not?". Four sessions of 3 minutes were performed by each child. Children with ASD were compared with typically developing control children matched with either non verbal mental age or chronological age. Response and

Classical many-body theory with retarded interactions: Dynamical irreversibility and determinism without probabilities

Energy Technology Data Exchange (ETDEWEB)

Zakharov, A.Yu., E-mail: Anatoly.Zakharov@novsu.ru; Zakharov, M.A., E-mail: ma_zakharov@list.ru

2016-01-28

The exact equations of motion for microscopic density of classical many-body system with account of inter-particle retarded interactions is derived. It is shown that interactions retardation leads to irreversible behavior of many-body systems. - Highlights: • A new form of equation of motion of classical many-body system is proposed. • Interactions retardation as one of the mechanisms of many-body system irreversibility. • Irreversibility and determinism without probabilities. • The possible way to microscopic foundation of thermodynamics.

Coefficient of reversibility and two particular cases of deterministic many body systems

International Nuclear Information System (INIS)

Grossu, Ioan Valeriu; Besliu, Calin; Jipa, Alexandru

2004-01-01

We discuss the importance of a new measure of chaos in study of nonlinear dynamic systems, the - coefficient of reversibility-. This is defined as the probability of returning in the same point of phasic space. Is very interesting to compare this coefficient with other measures like fractal dimension or Liapunov exponent. We have also studied two very interesting many body systems, both having any number of particles but a deterministic evolution. One system is composed by n particles initially at rest, having the same mass and interacting through harmonic bi-particle forces, other is composed by two types of particles (with mass m 1 and mass m 2 ) initially at rest and interacting too through harmonic bi-particle forces

Three-body interactions and the elastic constants of hcp solid 4He

Science.gov (United States)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-09-01

The effect of three-body interactions on the elastic properties of hexagonal close packed solid 4He is investigated using variational path integral (VPI) Monte Carlo simulations. The solid's nonzero elastic constants are calculated, at T = 0 K and for a range of molar volumes from 7.88 cm3/mol to 20.78 cm3/mol, from the bulk modulus and the three pure shear constants C0, C66, and C44. Three-body interactions are accounted for using our recently reported perturbative treatment based on the nonadditive three-body potential of Cencek et al. Previous studies have attempted to account for the effect of three-body interactions on the elastic properties of solid 4He; however, these calculations have treated zero point motions using either the Einstein or Debye approximations, which are insufficient in the molar volume range where solid 4He is characterized as a quantum solid. Our VPI calculations allow for a more accurate treatment of the zero point motions which include atomic correlation. From these calculations, we find that agreement with the experimental bulk modulus is significantly improved when three-body interactions are considered. In addition, three-body interactions result in non-negligible differences in the calculated pure shear constants and nonzero elastic constants, particularly at higher densities, where differences of up to 26.5% are observed when three-body interactions are included. We compare to the available experimental data and find that our results are generally in as good or better agreement with experiment as previous theoretical investigations.

On modelling the interaction between two rotating bodies with statistically distributed features: an application to dressing of grinding wheels

Science.gov (United States)

Spampinato, A.; Axinte, D. A.

2017-12-01

The mechanisms of interaction between bodies with statistically arranged features present characteristics common to different abrasive processes, such as dressing of abrasive tools. In contrast with the current empirical approach used to estimate the results of operations based on attritive interactions, the method we present in this paper allows us to predict the output forces and the topography of a simulated grinding wheel for a set of specific operational parameters (speed ratio and radial feed-rate), providing a thorough understanding of the complex mechanisms regulating these processes. In modelling the dressing mechanisms, the abrasive characteristics of both bodies (grain size, geometry, inter-space and protrusion) are first simulated; thus, their interaction is simulated in terms of grain collisions. Exploiting a specifically designed contact/impact evaluation algorithm, the model simulates the collisional effects of the dresser abrasives on the grinding wheel topography (grain fracture/break-out). The method has been tested for the case of a diamond rotary dresser, predicting output forces within less than 10% error and obtaining experimentally validated grinding wheel topographies. The study provides a fundamental understanding of the dressing operation, enabling the improvement of its performance in an industrial scenario, while being of general interest in modelling collision-based processes involving statistically distributed elements.

The three-body forces with two δ excitation and N+d scattering

International Nuclear Information System (INIS)

Uzu, Eizo; Koike, Yasuro; Yamaguchi, Masahiro; Kamada, Hiroyuki

2005-01-01

The differential cross section of 250 MeV N+d scattering was different from the results of Faddeev calculation. The possibility of δ excitation of two nucleons of deuteron in the initial state is considered and the degree of freedom of δδ excitation is applied to improve the three-body force effects. The system consisted of two nucleons, nucleon and δ particle, and two δparticles is called by NN, Nδ and δδ system, respectively. The first calculation was carried out by using AV14 potential as ordinary nuclear force and AV28 as interaction with Nδ and δδ as three-body. The results of calculation for 250 and 135 MeV N+d scattering showed no effect on the differential cross section but the large effect on the tensor resolving power. (S.Y.)

Two interacting Hofstadter butterflies

International Nuclear Information System (INIS)

Barelli, A.; Bellissard, J.; Jacquod, P.

1997-01-01

The problem of two interacting particles in a quasiperiodic potential is addressed. Using analytical and numerical methods, we explore the spectral properties and eigenstates structure from the weak to the strong interaction case. More precisely, a semiclassical approach based on noncommutative geometry techniques is used to understand the intricate structure of such a spectrum. An interaction induced localization effect is furthermore emphasized. We discuss the application of our results on a two-dimensional model of two particles in a uniform magnetic field with on-site interaction. copyright 1997 The American Physical Society

Hard Break-Up of Two-Nucleons and QCD Dynamics of NN Interaction

International Nuclear Information System (INIS)

Sargsian, Misak

2008-01-01

We discus recent developments in theory of high energy two-body break-up of few-nucleon systems. The characteristics of these reactions are such that the hard two-body quasielastic subprocess can be clearly separated from the accompanying soft subprocesses. We discuss in details the hard rescattering model (HRM) in which hard photodisintegration develops in two stages. At first, photon knocks-out an energetic quark which rescatters subsequently with a quark of the other nucleon. The latter provides a mechanism of sharing the initial high momentum of the photon between two outgoing nucleons. This final state hard rescattering can be expressed through the hard NN scattering amplitude. Within HRM we discuss hard break-up reactions involving D and 3 He targets and demonstrate how these reactions are sensitive to the dynamics of hard pn and pp interaction. Another development of HRM is the prediction of new helicity selection mechanism for hard two-body reactions, which was apparently confirmed in the recent JLab experiment.

Lipidation of BmAtg8 is required for autophagic degradation of p62 bodies containing ubiquitinated proteins in the silkworm, Bombyx mori.

Science.gov (United States)

Ji, Ming-Ming; Lee, Jae Man; Mon, Hiroaki; Iiyama, Kazuhiro; Tatsuke, Tsuneyuki; Morokuma, Daisuke; Hino, Masato; Yamashita, Mami; Hirata, Kazuma; Kusakabe, Takahiro

2017-10-01

p62/Sequestosome-1 (p62/SQSTM1, hereafter referred to as p62) is a major adaptor that allows ubiquitinated proteins to be degraded by autophagy, and Atg8 homologs are required for p62-mediated autophagic degradation, but their relationship is still not understood in Lepidopteran insects. Here it is clearly demonstrated that the silkworm homolog of mammalian p62, Bombyx mori p62 (Bmp62), forms p62 bodies depending on its Phox and Bem1p (PB1) and ubiquitin-associated (UBA) domains. These two domains are associated with Bmp62 binding to ubiquitinated proteins to form the p62 bodies, and the UBA domain is essential for the binding, but Bmp62 still self-associates without the PB1 or UBA domain. The p62 bodies in Bombyx cells are enclosed by BmAtg9-containing membranes and degraded via autophagy. It is revealed that the interaction between the Bmp62 AIM motif and BmAtg8 is critical for the autophagic degradation of the p62 bodies. Intriguingly, we further demonstrate that lipidation of BmAtg8 is required for the Bmp62-mediated complete degradation of p62 bodies by autophagy. Our results should be useful in future studies of the autophagic mechanism in Lepidopteran insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solving the Mind-Body Problem through Two Distinct Concepts: Internal-Mental Existence and Internal Mental Reality

OpenAIRE

Ion G. Motofei; David L. Rowland

2015-01-01

In a previous published paper, we initiated in this journal discussion about new perspectives regarding the organization and functioning of the mind, as a premise for addressing the mind-body problem. In this article, we continue focussing discussion on two distinct but interrelated concepts, internal-mental existence/ entity and internal-mental reality. These two psycho-physiological subunits of the mind interact each other in the form of an internal-mental interaction, having no sense if...

Three-body unitarity in the finite volume

Energy Technology Data Exchange (ETDEWEB)

Mai, M. [The George Washington University, Washington, DC (United States); Doering, M. [The George Washington University, Washington, DC (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2017-12-15

The physical interpretation of lattice QCD simulations, performed in a small volume, requires an extrapolation to the infinite volume. A method is proposed to perform such an extrapolation for three interacting particles at energies above threshold. For this, a recently formulated relativistic 3 → 3 amplitude based on the isobar formulation is adapted to the finite volume. The guiding principle is two- and three-body unitarity that imposes the imaginary parts of the amplitude in the infinite volume. In turn, these imaginary parts dictate the leading power-law finite-volume effects. It is demonstrated that finite-volume poles arising from the singular interaction, from the external two-body sub-amplitudes, and from the disconnected topology cancel exactly leaving only the genuine three-body eigenvalues. The corresponding quantization condition is derived for the case of three identical scalar-isoscalar particles and its numerical implementation is demonstrated. (orig.)

High-energy gravitational scattering and the general relativistic two-body problem

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Damour, Thibault

2018-02-01

A technique for translating the classical scattering function of two gravitationally interacting bodies into a corresponding (effective one-body) Hamiltonian description has been recently introduced [Phys. Rev. D 94, 104015 (2016), 10.1103/PhysRevD.94.104015]. Using this technique, we derive, for the first time, to second-order in Newton's constant (i.e. one classical loop) the Hamiltonian of two point masses having an arbitrary (possibly relativistic) relative velocity. The resulting (second post-Minkowskian) Hamiltonian is found to have a tame high-energy structure which we relate both to gravitational self-force studies of large mass-ratio binary systems, and to the ultra high-energy quantum scattering results of Amati, Ciafaloni and Veneziano. We derive several consequences of our second post-Minkowskian Hamiltonian: (i) the need to use special phase-space gauges to get a tame high-energy limit; and (ii) predictions about a (rest-mass independent) linear Regge trajectory behavior of high-angular-momenta, high-energy circular orbits. Ways of testing these predictions by dedicated numerical simulations are indicated. We finally indicate a way to connect our classical results to the quantum gravitational scattering amplitude of two particles, and we urge amplitude experts to use their novel techniques to compute the two-loop scattering amplitude of scalar masses, from which one could deduce the third post-Minkowskian effective one-body Hamiltonian.

The partition function of an interacting many body system

International Nuclear Information System (INIS)

Rummel, C.; Ankerhold, J.

2002-01-01

Based on the path integral approach the partition function of a many body system with separable two body interaction is calculated in the sense of a semiclassical approximation. The commonly used Gaussian type of approximation, known as the perturbed static path approximation (PSPA), breaks down near a crossover temperature due to instabilities of the classical mean field solution. It is shown how the PSPA is systematically improved within the crossover region by taking into account large non-Gaussian fluctuation and an approximation applicable down to very low temperatures is carried out. These findings are tested against exact results for the archetypical cases of a particle moving in a one dimensional double well and the exactly solvable Lipkin-Meshkov-Glick model. The extensions should have applications in finite systems at low temperatures as in nuclear physics and mesoscopic systems, e. g. for gap fluctuations in nano-scale superconducting devices previously studied within a PSPA type of approximation. (author)

Transformations of the perturbed two-body problem to unperturbed harmonic oscillators

Energy Technology Data Exchange (ETDEWEB)

Szebehely, V; Bond, V

1983-05-01

Singular, nonlinear, and Liapunov unstable equations are made regular and linear through transformations that change the perturbed planar problem of two bodies into unperturbed and undamped harmonic oscillators with constant coefficients, so that the stable solution may be immediately written in terms of the new variables. The use of arbitrary and special functions for the transformations allows the systematic discussion of previously introduced and novel anomalies. For the case of the unperturbed two-body problem, it is proved that if transformations are power functions of the radial variable, only the eccentric and the true anomalies (with the corresponding transformations of the radial variable) will result in harmonic oscillators. The present method significantly reduces computation requirements in autonomous space operations. 11 references.

Photogrammetry System and Method for Determining Relative Motion Between Two Bodies

Science.gov (United States)

Miller, Samuel A. (Inventor); Severance, Kurt (Inventor)

2014-01-01

A photogrammetry system and method provide for determining the relative position between two objects. The system utilizes one or more imaging devices, such as high speed cameras, that are mounted on a first body, and three or more photogrammetry targets of a known location on a second body. The system and method can be utilized with cameras having fish-eye, hyperbolic, omnidirectional, or other lenses. The system and method do not require overlapping fields-of-view if two or more cameras are utilized. The system and method derive relative orientation by equally weighting information from an arbitrary number of heterogeneous cameras, all with non-overlapping fields-of-view. Furthermore, the system can make the measurements with arbitrary wide-angle lenses on the cameras.

Two Independent Mushroom Body Output Circuits Retrieve the Six Discrete Components of Drosophila Aversive Memory

Directory of Open Access Journals (Sweden)

Emna Bouzaiane

2015-05-01

Full Text Available Understanding how the various memory components are encoded and how they interact to guide behavior requires knowledge of the underlying neural circuits. Currently, aversive olfactory memory in Drosophila is behaviorally subdivided into four discrete phases. Among these, short- and long-term memories rely, respectively, on the γ and α/β Kenyon cells (KCs, two distinct subsets of the ∼2,000 neurons in the mushroom body (MB. Whereas V2 efferent neurons retrieve memory from α/β KCs, the neurons that retrieve short-term memory are unknown. We identified a specific pair of MB efferent neurons, named M6, that retrieve memory from γ KCs. Moreover, our network analysis revealed that six discrete memory phases actually exist, three of which have been conflated in the past. At each time point, two distinct memory components separately recruit either V2 or M6 output pathways. Memory retrieval thus features a dramatic convergence from KCs to MB efferent neurons.

Vibrations versus collisions and the iterative structure of two-body dynamics

International Nuclear Information System (INIS)

Pfitzner, A.; Cassing, W.; Peter, A.

1993-11-01

The two-body correlation function is decomposed into two channel correlation functions for the pp- and the ph-channel. The associated coupled equations describe the evolution in the respective channels as well as their mixing. Integration of the ph-channel in terms of vibrational RPA-states yields a closed equation for the correlations in the pp-channel comprising phonon-particle coupling and a memory term. In the stationary limit the equation for a generalised effective interaction is derived which iterates both the G-matrix (ladders) and the polarisation matrix (loops), thus accounting nonperturbatively for the mixing of ladders and loops. (orig.)

Inchworm movement of two rings switching onto a thread by biased Brownian diffusion represent a three-body problem.

Science.gov (United States)

Benson, Christopher R; Maffeo, Christopher; Fatila, Elisabeth M; Liu, Yun; Sheetz, Edward G; Aksimentiev, Aleksei; Singharoy, Abhishek; Flood, Amar H

2018-05-07

The coordinated motion of many individual components underpins the operation of all machines. However, despite generations of experience in engineering, understanding the motion of three or more coupled components remains a challenge, known since the time of Newton as the "three-body problem." Here, we describe, quantify, and simulate a molecular three-body problem of threading two molecular rings onto a linear molecular thread. Specifically, we use voltage-triggered reduction of a tetrazine-based thread to capture two cyanostar macrocycles and form a [3]pseudorotaxane product. As a consequence of the noncovalent coupling between the cyanostar rings, we find the threading occurs by an unexpected and rare inchworm-like motion where one ring follows the other. The mechanism was derived from controls, analysis of cyclic voltammetry (CV) traces, and Brownian dynamics simulations. CVs from two noncovalently interacting rings match that of two covalently linked rings designed to thread via the inchworm pathway, and they deviate considerably from the CV of a macrocycle designed to thread via a stepwise pathway. Time-dependent electrochemistry provides estimates of rate constants for threading. Experimentally derived parameters (energy wells, barriers, diffusion coefficients) helped determine likely pathways of motion with rate-kinetics and Brownian dynamics simulations. Simulations verified intercomponent coupling could be separated into ring-thread interactions for kinetics, and ring-ring interactions for thermodynamics to reduce the three-body problem to a two-body one. Our findings provide a basis for high-throughput design of molecular machinery with multiple components undergoing coupled motion.

Simple ``invariance'' of two-body decay kinematics

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Agashe, Kaustubh; Franceschini, Roberto; Kim, Doojin

2013-09-01

We study the two-body decay of a mother particle into a massless daughter. We further assume that the mother particle is unpolarized and has a generic boost distribution in the laboratory frame. In this case, we show analytically that the laboratory frame energy distribution of the massless decay product has a peak, whose location is identical to the (fixed) energy of that particle in the rest frame of the corresponding mother particle. Given its simplicity and “invariance” under changes in the boost distribution of the mother particle, our finding should be useful for the determination of masses of mother particles. In particular, we anticipate that such a procedure will then not require a full reconstruction of this two-body decay chain (or, for that matter, information about the rest of the event). With this eventual goal in mind, we make a proposal for extracting the peak position by fitting the data to a well-motivated analytic function describing the shape of such an energy distribution. This fitting function is then tested on the theoretical prediction for top quark pair production and its decay, and it is found to be quite successful in this regard. As a proof of principle of the usefulness of our observation, we apply it for measuring the mass of the top quark at the LHC, using simulated data and including experimental effects.

An Evaluation-Driven Design Approach to Develop Learning Environments Based on Full-Body Interaction

Science.gov (United States)

Malinverni, Laura; Schaper, Marie-Monique; Pares, Narcís

2016-01-01

The development of learning environments based on full-body interaction has become an increasingly important field of research in recent years. However, the design and evaluation strategies currently used present some significant limitations. Two major shortcomings are: the inadequate involvement of children in the design process and a lack of…

Universality of many-body two-nucleon momentum distributions: Correlated nucleon spectral function of complex nuclei

Science.gov (United States)

Ciofi degli Atti, Claudio; Morita, Hiko

2017-12-01

Background: The nuclear spectral function is a fundamental quantity that describes the mean-field and short-range correlation dynamics of nucleons embedded in the nuclear medium; its knowledge is a prerequisite for the interpretation of various electroweak scattering processes off nuclear targets aimed at providing fundamental information on strong and weak interactions. Whereas in the case of the three-nucleon and, partly, the four-nucleon systems, the spectral function can be calculated ab initio within a nonrelativistic many-body Schroedinger approach, in the case of complex nuclei only models of the correlated, high-momentum part of the spectral function are available so far. Purpose: The purpose of this paper is to present a new approach such that the spectral function for a specific nucleus can be obtained from a reliable many-body calculation based upon realistic nucleon-nucleon interactions, thus avoiding approximations leading to adjustable parameters. Methods: The expectation value of the nuclear many-body Hamiltonian, containing realistic nucleon-nucleon interaction of the Argonne family, is evaluated variationally by a normalization-conserving linked-cluster expansion and the resulting many-body correlated wave functions are used to calculate the one-nucleon and the two-nucleon momentum distributions; by analyzing the high-momentum behavior of the latter, the spectral function can be expressed in terms of a transparent convolution formula involving the relative and center-of-mass (c.m.) momentum distributions in specific regions of removal energy E and momentum k . Results: It is found that as a consequence of the factorization of the many-body wave functions at short internucleon separations, the high-momentum behavior of the two-nucleon momentum distributions in A =3 ,4 ,12 ,16 ,40 nuclei factorizes, at proper values of the relative and c.m. momenta, into the c.m. and relative momentum distributions, with the latter exhibiting a universal A

Protection of Urban Water body Infrastructure - Policy Requirements

Science.gov (United States)

Neelakantan, T. R.; Ramakrishnan, K.

2017-07-01

Water body is an important infrastructure of urban landscape. Water bodies like tanks and ponds are constructed to harvest rainwater for local use. Such water bodies serve many environmental functions including flood and soil erosion control and are useful for irrigation, drinking water supply and groundwater recharge. A large number of water bodies recently have been lost due to anthropogenic activities and the remaining water bodies are under stress due to risk of degradation. There are many phases to solve or control the problem; starting from stopping the abuse, to restoration to monitoring and maintenance. In this situation, the existing urban and peri-urban water bodies are to be preserved and rehabilitated. In this study, policy requirements for the protection (preservation and rehabilitation) of water bodies are analyzed with special reference to Thanjavur city. Thanjavur city has many water bodies and moat around the Big-Temple and the palace, and stands as an evidence for water management in ancient days. These water bodies are to be protected and used properly for sustainable growth of the city. This paper envisages the following three: (a) need for evaluation of hydraulic and hydrologic properties of the water bodies for conserving rainwater and controlling flood water in the existing urban water bodies; (b) need for evaluation of potential of socio-environmental services by the water bodies, and (c) need for developing a relative importance index for protection of water bodies to prioritize the remedial actions.

Elastic interactions between hydrogen atoms in metals. II. Elastic interaction energies

International Nuclear Information System (INIS)

Shirley, A.I.; Hall, C.K.

1986-01-01

The fully harmonic lattice approximation derived in a previous paper is used to calculate the elastic interaction energies in the niobium-hydrogen system. The permanent-direct, permanent-indirect, induced-direct, and induced-indirect forces calculated previously each give rise to a corresponding elastic interaction between hydrogen atoms. The latter three interactions have three- and four-body terms in addition to the usual two-body terms. These quantities are calculated and compared with the corresponding two-body permanent elastic interactions obtained in the harmonic-approximation treatment of Horner and Wagner. The results show that the total induced elastic energy is approximately (1/3) the size of the total permanent elastic energy and opposite to it in sign. The total elastic energy due to three-body interactions is approximately (1/4) the size of the total two-body elastic energy, while the total four-body elastic energy is approximately 5% of the total two-body energy. These additional elastic energies are expected to have a profound effect on the thermodynamic and phase-change behavior of a metal hydride

A 3D, fully Eulerian, VOF-based solver to study the interaction between two fluids and moving rigid bodies using the fictitious domain method

Science.gov (United States)

Pathak, Ashish; Raessi, Mehdi

2016-04-01

We present a three-dimensional (3D) and fully Eulerian approach to capturing the interaction between two fluids and moving rigid structures by using the fictitious domain and volume-of-fluid (VOF) methods. The solid bodies can have arbitrarily complex geometry and can pierce the fluid-fluid interface, forming contact lines. The three-phase interfaces are resolved and reconstructed by using a VOF-based methodology. Then, a consistent scheme is employed for transporting mass and momentum, allowing for simulations of three-phase flows of large density ratios. The Eulerian approach significantly simplifies numerical resolution of the kinematics of rigid bodies of complex geometry and with six degrees of freedom. The fluid-structure interaction (FSI) is computed using the fictitious domain method. The methodology was developed in a message passing interface (MPI) parallel framework accelerated with graphics processing units (GPUs). The computationally intensive solution of the pressure Poisson equation is ported to GPUs, while the remaining calculations are performed on CPUs. The performance and accuracy of the methodology are assessed using an array of test cases, focusing individually on the flow solver and the FSI in surface-piercing configurations. Finally, an application of the proposed methodology in simulations of the ocean wave energy converters is presented.

A statistical analysis of the body condition of cows from two veterinary stations in Zimbabwe

International Nuclear Information System (INIS)

Saporu, F.W.O.

2003-12-01

The improvement of livestock production is important for Zimbabwe's agriculturally base economy. This paper examines the relationship between the body condition and metabolic parameters of female cows, for the better understanding of traditional livestock farming in Zimbabwe. The data analysed are part of the baseline data on the improvement of livestock production, collected from two sites Chinamora and Bulawayo. Body condition is indexed by body score. Thirty-five variables are examined. The variable selection method employed is stepwise regression. Regression model assumptions of normality and independent observations are checked using normal probability plot and Durbin-Watson statistics for autocorrelation of residuals. Collinearity and outlier problems are examined using eigenanalysis and influence statistics. The effect of some factors, such as, site, which relates to livestock management, parity and season, categorized by the quality of forage available for grazing, are also studied. The data are analysed using SAS statistical package on a Personal Computer. The results show that only about four variables substantially influence the relationship in each of the two sites considered. For the better managed site, Bulawayo, these are PCV, Calcium and WBC. Strongyles, Progesterone Level, Phosphate and HB are obtained in Chinamora. Negative correlation coefficient corresponds to strongyles only. That is, the effect of stronglyes is to reduce the value of bodyscore. For other variables, an improvement in their respective values will bring about improved body condition. Site difference is identified as a factor affecting the relationship. This emphasizes the role of good management in livestock production. Parity and season are also identified. Only two interactions are significant; site-season and a progesterone level-season interaction. The latter is obtained only in Chinamora site and it can be deduced that the cyclic cows are exposed to the risk of loosing their

Universality in few-body systems with large scattering length

International Nuclear Information System (INIS)

Hammer, H.-W.

2005-01-01

Effective Field Theory (EFT) provides a powerful framework that exploits a separation of scales in physical systems to perform systematically improvable, model-independent calculations. Particularly interesting are few-body systems with short-range interactions and large two-body scattering length. Such systems display remarkable universal features. In systems with more than two particles, a three-body force with limit cycle behavior is required for consistent renormalization already at leading order. We will review this EFT and some of its applications in the physics of cold atoms and nuclear physics. In particular, we will discuss the possibility of an infrared limit cycle in QCD. Recent extensions of the EFT approach to the four-body system and N-boson droplets in two spatial dimensions will also be addressed

Three-body forces in p-shell nuclei

International Nuclear Information System (INIS)

Hees, A.G.M. van; Booten, J.G.L.; Glaudemans, P.W.M.

1990-01-01

Within the (0 + 1)ℎω shell-model space for p-shell nuclei we found that a schematic three-body interaction in addition to a translationally invariant two-body interaction leads to a strongly improved description of energy levels. The present three-body interaction is related to the Δ-isobar intermediate-state model of the two-pion exchange three-nucleon interaction. (orig.)

Charge separation at nanoscale interfaces: energy-level alignment including two-quasiparticle interactions.

Science.gov (United States)

Li, Huashan; Lin, Zhibin; Lusk, Mark T; Wu, Zhigang

2014-10-21

The universal and fundamental criteria for charge separation at interfaces involving nanoscale materials are investigated. In addition to the single-quasiparticle excitation, all the two-quasiparticle effects including exciton binding, Coulomb stabilization, and exciton transfer are considered, which play critical roles on nanoscale interfaces for optoelectronic applications. We propose a scheme allowing adding these two-quasiparticle interactions on top of the single-quasiparticle energy level alignment for determining and illuminating charge separation at nanoscale interfaces. Employing the many-body perturbation theory based on Green's functions, we quantitatively demonstrate that neglecting or simplifying these crucial two-quasiparticle interactions using less accurate methods is likely to predict qualitatively incorrect charge separation behaviors at nanoscale interfaces where quantum confinement dominates.

Topological color codes and two-body quantum lattice Hamiltonians

Science.gov (United States)

Kargarian, M.; Bombin, H.; Martin-Delgado, M. A.

2010-02-01

fermionized Hamiltonian from being reduced to a quadratic form owing to interacting gauge fields. We also propose another construction for the two-body Hamiltonian based on the connection between color codes and cluster states. The corresponding two-body Hamiltonian encodes a cluster state defined on a bipartite lattice as its low-energy spectrum, and subsequent selective measurements give rise to the color code model. We discuss this latter approach along with the construction based on the ruby lattice.

The two-body problem of a pseudo-rigid body and a rigid sphere

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.

2012-01-01

n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....

Design Requirements for Communication-Intensive Interactive Applications

Science.gov (United States)

Bolchini, Davide; Garzotto, Franca; Paolini, Paolo

Online interactive applications call for new requirements paradigms to capture the growing complexity of computer-mediated communication. Crafting successful interactive applications (such as websites and multimedia) involves modeling the requirements for the user experience, including those leading to content design, usable information architecture and interaction, in profound coordination with the communication goals of all stakeholders involved, ranging from persuasion to social engagement, to call for action. To face this grand challenge, we propose a methodology for modeling communication requirements and provide a set of operational conceptual tools to be used in complex projects with multiple stakeholders. Through examples from real-life projects and lessons-learned from direct experience, we draw on the concepts of brand, value, communication goals, information and persuasion requirements to systematically guide analysts to master the multifaceted connections of these elements as drivers to inform successful communication designs.

On the special relativistic two-body problem

International Nuclear Information System (INIS)

Afanas'ev, G.N.; Asanov, R.A.

1979-01-01

The Poincare method is applied to the consideration of the two-body problem within the Special Relativity. The formulation of the theory contains two arbitrary functions of the Lorentz invariants. A specific choice of these functions leads to the correct description of three crucial experiments of the General Relativity. The expansion on the inverse powers of the light velocity being performed, the approximate Lorentz covariant two-body equations without retardation effects are obtained

Energy requirements and perceived body discomfort of the various ...

African Journals Online (AJOL)

The main aim of this preliminary study was to assess the energy cost of the various sub tasks required of workers during manual sugar cane harvesting. A secondary aim was to assess body mass changes, levels of dehydration and body discomfort. Eight workers were randomly selected to participate in this pilot study and ...

Fungible dynamics: There are only two types of entangling multiple-qubit interactions

International Nuclear Information System (INIS)

Bremner, Michael J.; Dodd, Jennifer L.; Nielsen, Michael A.; Bacon, Dave

2004-01-01

What interactions are sufficient to simulate arbitrary quantum dynamics in a composite quantum system? It has been shown that all two-body Hamiltonian evolutions can be simulated using any fixed two-body entangling n-qubit Hamiltonian and fast local unitaries. By entangling we mean that every qubit is coupled to every other qubit, if not directly, then indirectly via intermediate qubits. We extend this study to the case where interactions may involve more than two qubits at a time. We find necessary and sufficient conditions for an arbitrary n-qubit Hamiltonian to be dynamically universal, that is, able to simulate any other Hamiltonian acting on n qubits, possibly in an inefficient manner. We prove that an entangling Hamiltonian is dynamically universal if and only if it contains at least one coupling term involving an even number of interacting qubits. For odd entangling Hamiltonians, i.e., Hamiltonians with couplings that involve only an odd number of qubits, we prove that dynamic universality is possible on an encoded set of n-1 logical qubits. We further prove that an odd entangling Hamiltonian can simulate any other odd Hamiltonian and classify the algebras that such Hamiltonians generate. Thus, our results show that up to local unitary operations, there are only two fundamentally different types of entangling Hamiltonian on n qubits. We also demonstrate that, provided the number of qubits directly coupled by the Hamiltonian is bounded above by a constant, our techniques can be made efficient

Computational investigation of large-scale vortex interaction with flexible bodies

Science.gov (United States)

Connell, Benjamin; Yue, Dick K. P.

2003-11-01

The interaction of large-scale vortices with flexible bodies is examined with particular interest paid to the energy and momentum budgets of the system. Finite difference direct numerical simulation of the Navier-Stokes equations on a moving curvilinear grid is coupled with a finite difference structural solver of both a linear membrane under tension and linear Euler-Bernoulli beam. The hydrodynamics and structural dynamics are solved simultaneously using an iterative procedure with the external structural forcing calculated from the hydrodynamics at the surface and the flow-field velocity boundary condition given by the structural motion. We focus on an investigation into the canonical problem of a vortex-dipole impinging on a flexible membrane. It is discovered that the structural properties of the membrane direct the interaction in terms of the flow evolution and the energy budget. Pressure gradients associated with resonant membrane response are shown to sustain the oscillatory motion of the vortex pair. Understanding how the key mechanisms in vortex-body interactions are guided by the structural properties of the body is a prerequisite to exploiting these mechanisms.

Nonlocality in many-body quantum systems detected with two-body correlators

Energy Technology Data Exchange (ETDEWEB)

Tura, J., E-mail: jordi.tura@icfo.es [ICFO—Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Augusiak, R.; Sainz, A.B. [ICFO—Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Lücke, B.; Klempt, C. [Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, D-30167 Hannover (Germany); Lewenstein, M.; Acín, A. [ICFO—Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); ICREA—Institució Catalana de Recerca i Estudis Avançats, Lluis Campanys 3, 08010 Barcelona (Spain)

2015-11-15

Contemporary understanding of correlations in quantum many-body systems and in quantum phase transitions is based to a large extent on the recent intensive studies of entanglement in many-body systems. In contrast, much less is known about the role of quantum nonlocality in these systems, mostly because the available multipartite Bell inequalities involve high-order correlations among many particles, which are hard to access theoretically, and even harder experimentally. Standard, “theorist- and experimentalist-friendly” many-body observables involve correlations among only few (one, two, rarely three...) particles. Typically, there is no multipartite Bell inequality for this scenario based on such low-order correlations. Recently, however, we have succeeded in constructing multipartite Bell inequalities that involve two- and one-body correlations only, and showed how they revealed the nonlocality in many-body systems relevant for nuclear and atomic physics [Tura et al., Science 344 (2014) 1256]. With the present contribution we continue our work on this problem. On the one hand, we present a detailed derivation of the above Bell inequalities, pertaining to permutation symmetry among the involved parties. On the other hand, we present a couple of new results concerning such Bell inequalities. First, we characterize their tightness. We then discuss maximal quantum violations of these inequalities in the general case, and their scaling with the number of parties. Moreover, we provide new classes of two-body Bell inequalities which reveal nonlocality of the Dicke states—ground states of physically relevant and experimentally realizable Hamiltonians. Finally, we shortly discuss various scenarios for nonlocality detection in mesoscopic systems of trapped ions or atoms, and by atoms trapped in the vicinity of designed nanostructures.

Interaction Design for and with the Lived Body: Some Implications of Merleau-Ponty’s Phenomenology

DEFF Research Database (Denmark)

Svanæs, Dag

2013-01-01

: the active and embodied nature of perception, including the body’s ability to extent its sensory apparatus through digital technology; and (2) kinaesthetic creativity: the body’s ability to relate in a direct and creative fashion with the “feel” dimension of interactive products during the design process....... for his discussion of the bodily nature of embodied interaction. This article extends Dourish’s work to introduce the human-computer interaction community to ideas related to Merleau-Ponty’s concept of the lived body. It also provides a detailed analysis of two related topics: (1) embodied perception...

Complete characterization of the ground-space structure of two-body frustration-free Hamiltonians for qubits

International Nuclear Information System (INIS)

Ji Zhengfeng; Wei Zhaohui; Zeng Bei

2011-01-01

The problem of finding the ground state of a frustration-free Hamiltonian carrying only two-body interactions between qubits is known to be solvable in polynomial time. It is also shown recently that, for any such Hamiltonian, there is always a ground state that is a product of single- or two-qubit states. However, it remains unclear whether the whole ground space is of any succinct structure. Here, we give a complete characterization of the ground space of any two-body frustration-free Hamiltonian of qubits. Namely, it is a span of tree tensor network states of the same tree structure. This characterization allows us to show that the problem of determining the ground-state degeneracy is as hard as, but no harder than, its classical analog.

Some general features of two body reactions in K-p interactions at 3 GeV/c

International Nuclear Information System (INIS)

Badier, J.; Demoulin, M.; Goldberg, J.

1966-06-01

The differential and total cross sections of two-body reactions produced in 3 GeV/c K - proton collisions are presented. Their variation as a function of the baryonic number, strangeness, and isospin of the t and u cross channels is analyzed, as well as some implications of a baryon exchange mechanism. (authors) [fr

Harmonically trapped cold atom systems: Few-body dynamics and application to many-body thermodynamics

Science.gov (United States)

Daily, Kevin Michael

Underlying the many-body effects of ultracold atomic gases are the few-body dynamics and interparticle interactions. Moreover, the study of few-body systems on their own has accelerated due to confining few atoms in each well of a deep optical lattice or in a single microtrap. This thesis studies the microscopic properties of few-body systems under external spherically symmetric harmonic confinement and how the few-body properties translate to the many-body system. Bosonic and fermionic few-body systems are considered and the dependence of the energetics and other quantities are investigated as functions of the s-wave scattering length, the mass ratio and the temperature. It is found that the condensate fraction of a weakly-interacting trapped Bose gas depletes quadratically with the s-wave scattering length. The next order term in the depletion depends not only, as might be expected naively, on the s-wave scattering length and the effective range but additionally on a two-body parameter that is not needed to reproduce the energy of weakly-interacting trapped Bose gases. This finding has important implications for effective field theory treatments of the system. Weakly-interacting atomic and molecular two-component Fermi gases with equal masses are described using perturbative approaches. The energy shifts are tabulated and interpreted, and a measure of the molecular condensate fraction is developed. We develop a measure of the molecular condensate fraction using the two-body density matrix and we develop a model of the spherical component of the momentum distribution that agrees well with stochastic variational calculations. We establish the existence of intersystem degeneracies for equal mass two-component Fermi gases with zero-range interactions, where the eigen energies of the spin-imbalanced system are degenerate with a subset of the eigen energies of the more spin-balanced system and the same total number of fermions. For unequal mass two-component Fermi

Hydrodynamic interaction of two particles in confined linear shear flow at finite Reynolds number

Science.gov (United States)

Yan, Yiguang; Morris, Jeffrey F.; Koplik, Joel

2007-11-01

We discuss the hydrodynamic interactions of two solid bodies placed in linear shear flow between parallel plane walls in a periodic geometry at finite Reynolds number. The computations are based on the lattice Boltzmann method for particulate flow, validated here by comparison to previous results for a single particle. Most of our results pertain to cylinders in two dimensions but some examples are given for spheres in three dimensions. Either one mobile and one fixed particle or else two mobile particles are studied. The motion of a mobile particle is qualitatively similar in both cases at early times, exhibiting either trajectory reversal or bypass, depending upon the initial vector separation of the pair. At longer times, if a mobile particle does not approach a periodic image of the second, its trajectory tends to a stable limit point on the symmetry axis. The effect of interactions with periodic images is to produce nonconstant asymptotic long-time trajectories. For one free particle interacting with a fixed second particle within the unit cell, the free particle may either move to a fixed point or take up a limit cycle. Pairs of mobile particles starting from symmetric initial conditions are shown to asymptotically reach either fixed points, or mirror image limit cycles within the unit cell, or to bypass one another (and periodic images) indefinitely on a streamwise periodic trajectory. The limit cycle possibility requires finite Reynolds number and arises as a consequence of streamwise periodicity when the system length is sufficiently short.

Light-induced attractive force between two metal bodies separated by a subwavelength slit

International Nuclear Information System (INIS)

Nesterov, Vladimir; Frumin, Leonid

2011-01-01

A novel light-induced attractive force which acts as a force with negative light pressure has been revealed. The force arises by the interaction of plasmon polaritons which are excited at the surface of metal when a transverse magnetic mode propagates through a subwavelength slit between two metal bodies. The estimation of the repulsive force acting on the metal walls of the slit in the case of subwavelength TE mode propagation along the slit is presented. The explicit analytical expressions of light-induced forces between two macroscopic metal bodies or films separated by a subwavelength slit have been derived. These forces could be used to manipulate metallic macro-, micro- and nano-objects in vacuum or in a dielectric medium. Estimations of these light-induced forces show that the forces are sufficient for measurements and practical applications

Emerging bosons with three-body interactions from spin-1 atoms in optical lattices

International Nuclear Information System (INIS)

Mazza, L.; Rizzi, M.; Cirac, J. I.; Lewenstein, M.

2010-01-01

We study two many-body systems of bosons interacting via an infinite three-body contact repulsion in a lattice: a pairs quasicondensate induced by correlated hopping and the discrete version of the Pfaffian wave function. We propose to experimentally realize systems characterized by such interaction by means of a proper spin-1 lattice Hamiltonian: spin degrees of freedom are locally mapped into occupation numbers of emerging bosons, in a fashion similar to spin-1/2 and hardcore bosons. Such a system can be realized with ultracold spin-1 atoms in a Mott insulator with a filling factor of 1. The high versatility of these setups allows us to engineer spin-hopping operators breaking the SU(2) symmetry, as needed to approximate interesting bosonic Hamiltonians with three-body hardcore constraint. For this purpose we combine bichromatic spin-independent superlattices and Raman transitions to induce a different hopping rate for each spin orientation. Finally, we illustrate how our setup could be used to experimentally realize the first setup, that is, the transition to a pairs quasicondensed phase of the emerging bosons. We also report on a route toward the realization of a discrete bosonic Pfaffian wave function and list some open problems for reaching this goal.

Fracton topological order from nearest-neighbor two-spin interactions and dualities

Science.gov (United States)

Slagle, Kevin; Kim, Yong Baek

2017-10-01

Fracton topological order describes a remarkable phase of matter, which can be characterized by fracton excitations with constrained dynamics and a ground-state degeneracy that increases exponentially with the length of the system on a three-dimensional torus. However, previous models exhibiting this order require many-spin interactions, which may be very difficult to realize in a real material or cold atom system. In this work, we present a more physically realistic model which has the so-called X-cube fracton topological order [Vijay, Haah, and Fu, Phys. Rev. B 94, 235157 (2016), 10.1103/PhysRevB.94.235157] but only requires nearest-neighbor two-spin interactions. The model lives on a three-dimensional honeycomb-based lattice with one to two spin-1/2 degrees of freedom on each site and a unit cell of six sites. The model is constructed from two orthogonal stacks of Z2 topologically ordered Kitaev honeycomb layers [Kitaev, Ann. Phys. 321, 2 (2006), 10.1016/j.aop.2005.10.005], which are coupled together by a two-spin interaction. It is also shown that a four-spin interaction can be included to instead stabilize 3+1D Z2 topological order. We also find dual descriptions of four quantum phase transitions in our model, all of which appear to be discontinuous first-order transitions.

Bodystorming for Movement-Based Interaction Design

Directory of Open Access Journals (Sweden)

Elena Márquez Segura

2016-11-01

Full Text Available After a decade of movement-based interaction in human–computer interaction, designing for the moving body still remains a challenge. Research in this field requires methods to help access, articulate, and harness embodied experiences in ways that can inform the design process. To address this challenge, this article appropriates bodystorming, an embodied ideation method for movement-based interaction design. The proposed method allows for early consideration of the physical, collocated, and social aspects of a designed activity as illustrated with two explorative workshops in different application domains: interactive body games and interactive performances. Using a qualitative methods approach, we used video material from the workshops, feedback from participants, and our own experience as participants and facilitators to outline important characteristics of the bodystorming method in the domain of movement-based interaction. The proposed method is compared with previous ones and application implications are discussed.

Transcriptome analysis of fat bodies from two brown planthopper (Nilaparvata lugens) populations with different virulence levels in rice.

Science.gov (United States)

Yu, Haixin; Ji, Rui; Ye, Wenfeng; Chen, Hongdan; Lai, Wenxiang; Fu, Qiang; Lou, Yonggen

2014-01-01

The brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs) from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies and will be useful in examining the interactions between the fat body and virulence

Tomographic reconstruction of OH* chemiluminescence in two interacting turbulent flames

International Nuclear Information System (INIS)

Worth, Nicholas A; Dawson, James R

2013-01-01

The tomographic reconstruction of OH* chemiluminescence was performed on two interacting turbulent premixed bluff-body stabilized flames under steady flow conditions and acoustic excitation. These measurements elucidate the complex three-dimensional (3D) vortex–flame interactions which have previously not been accessible. The experiment was performed using a single camera and intensifier, with multiple views acquired by repositioning the camera, permitting calculation of the mean and phase-averaged volumetric OH* distributions. The reconstructed flame structure and phase-averaged dynamics are compared with OH planar laser-induced fluorescence and flame surface density measurements for the first time. The volumetric data revealed that the large-scale vortex–flame structures formed along the shear layers of each flame collide when the two flames meet, resulting in complex 3D flame structures in between the two flames. With a fairly simple experimental setup, it is shown that the tomographic reconstruction of OH* chemiluminescence in forced flames is a powerful tool that can yield important physical insights into large-scale 3D flame dynamics that are important in combustion instability. (paper)

Properties of the elementary KN and anti KN interactions

International Nuclear Information System (INIS)

Dover, C.B.

1979-01-01

Kaon beams offer exciting prospects for the study of both nuclear and hypernuclear physics. Experiments on hypernucleus formation via the (K - ,π - ) reaction, as well as elastic and inelastic scattering of K +- from nuclei, are already underway. The theoretical analysis of such experiments requires an understanding of the underlying two-body K +- n interaction. The main features of these elementary amplitudes, as revealed through phase shift analyses and meson exchange model are reviewed. It is indicated how the properties of the two body interaction (isospin dependence, Y* and Z* resonance formation, strangeness exchange, etc.) are reflected in reactions induced by kaons in nuclei. 81 references

Secure anonymous mutual authentication for star two-tier wireless body area networks.

Science.gov (United States)

Ibrahim, Maged Hamada; Kumari, Saru; Das, Ashok Kumar; Wazid, Mohammad; Odelu, Vanga

2016-10-01

Mutual authentication is a very important service that must be established between sensor nodes in wireless body area network (WBAN) to ensure the originality and integrity of the patient's data sent by sensors distributed on different parts of the body. However, mutual authentication service is not enough. An adversary can benefit from monitoring the traffic and knowing which sensor is in transmission of patient's data. Observing the traffic (even without disclosing the context) and knowing its origin, it can reveal to the adversary information about the patient's medical conditions. Therefore, anonymity of the communicating sensors is an important service as well. Few works have been conducted in the area of mutual authentication among sensor nodes in WBAN. However, none of them has considered anonymity among body sensor nodes. Up to our knowledge, our protocol is the first attempt to consider this service in a two-tier WBAN. We propose a new secure protocol to realize anonymous mutual authentication and confidential transmission for star two-tier WBAN topology. The proposed protocol uses simple cryptographic primitives. We prove the security of the proposed protocol using the widely-accepted Burrows-Abadi-Needham (BAN) logic, and also through rigorous informal security analysis. In addition, to demonstrate the practicality of our protocol, we evaluate it using NS-2 simulator. BAN logic and informal security analysis prove that our proposed protocol achieves the necessary security requirements and goals of an authentication service. The simulation results show the impact on the various network parameters, such as end-to-end delay and throughput. The nodes in the network require to store few hundred bits. Nodes require to perform very few hash invocations, which are computationally very efficient. The communication cost of the proposed protocol is few hundred bits in one round of communication. Due to the low computation cost, the energy consumed by the nodes is

Effective linear two-body method for many-body problems in atomic and nuclear physics

International Nuclear Information System (INIS)

Kim, Y.E.; Zubarev, A.L.

2000-01-01

We present an equivalent linear two-body method for the many body problem, which is based on an approximate reduction of the many-body Schroedinger equation by the use of a variational principle. The method is applied to several problems in atomic and nuclear physics. (author)

Distinct Mechanisms of Recognizing Endosomal Sorting Complex Required for Transport III (ESCRT-III) Protein IST1 by Different Microtubule Interacting and Trafficking (MIT) Domains*

Science.gov (United States)

Guo, Emily Z.; Xu, Zhaohui

2015-01-01

The endosomal sorting complex required for transport (ESCRT) machinery is responsible for membrane remodeling in a number of biological processes including multivesicular body biogenesis, cytokinesis, and enveloped virus budding. In mammalian cells, efficient abscission during cytokinesis requires proper function of the ESCRT-III protein IST1, which binds to the microtubule interacting and trafficking (MIT) domains of VPS4, LIP5, and Spartin via its C-terminal MIT-interacting motif (MIM). Here, we studied the molecular interactions between IST1 and the three MIT domain-containing proteins to understand the structural basis that governs pairwise MIT-MIM interaction. Crystal structures of the three molecular complexes revealed that IST1 binds to the MIT domains of VPS4, LIP5, and Spartin using two different mechanisms (MIM1 mode versus MIM3 mode). Structural comparison revealed that structural features in both MIT and MIM contribute to determine the specific binding mechanism. Within the IST1 MIM sequence, two phenylalanine residues were shown to be important in discriminating MIM1 versus MIM3 binding. These observations enabled us to deduce a preliminary binding code, which we applied to provide CHMP2A, a protein that normally only binds the MIT domain in the MIM1 mode, the additional ability to bind the MIT domain of Spartin in the MIM3 mode. PMID:25657007

Distinct mechanisms of recognizing endosomal sorting complex required for transport III (ESCRT-III) protein IST1 by different microtubule interacting and trafficking (MIT) domains.

Science.gov (United States)

Guo, Emily Z; Xu, Zhaohui

2015-03-27

The endosomal sorting complex required for transport (ESCRT) machinery is responsible for membrane remodeling in a number of biological processes including multivesicular body biogenesis, cytokinesis, and enveloped virus budding. In mammalian cells, efficient abscission during cytokinesis requires proper function of the ESCRT-III protein IST1, which binds to the microtubule interacting and trafficking (MIT) domains of VPS4, LIP5, and Spartin via its C-terminal MIT-interacting motif (MIM). Here, we studied the molecular interactions between IST1 and the three MIT domain-containing proteins to understand the structural basis that governs pairwise MIT-MIM interaction. Crystal structures of the three molecular complexes revealed that IST1 binds to the MIT domains of VPS4, LIP5, and Spartin using two different mechanisms (MIM1 mode versus MIM3 mode). Structural comparison revealed that structural features in both MIT and MIM contribute to determine the specific binding mechanism. Within the IST1 MIM sequence, two phenylalanine residues were shown to be important in discriminating MIM1 versus MIM3 binding. These observations enabled us to deduce a preliminary binding code, which we applied to provide CHMP2A, a protein that normally only binds the MIT domain in the MIM1 mode, the additional ability to bind the MIT domain of Spartin in the MIM3 mode. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Two novel classes of solvable many-body problems of goldfish type with constraints

Energy Technology Data Exchange (ETDEWEB)

Calogero, F [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , 00185 Rome (Italy); Gomez-Ullate, D [Departamento de Fisica Teorica II, Universidad Complutense, 28040 Madrid (Spain)

2007-05-18

Two novel classes of many-body models with nonlinear interactions 'of goldfish type' are introduced. They are solvable provided the initial data satisfy a single constraint (in one case; in the other, two constraints), i.e., for such initial data the solution of their initial-value problem can be achieved via algebraic operations, such as finding the eigenvalues of given matrices or equivalently the zeros of known polynomials. Entirely isochronous versions of some of these models are also exhibited, i.e., versions of these models whose nonsingular solutions are all completely periodic with the same period.

Body composition and net energy requirements of Brazilian Somali lambs

Directory of Open Access Journals (Sweden)

Elzânia S. Pereira

2014-12-01

Full Text Available The aim of this study was to determine the energy requirements for maintenance (NEm and growth of 48 Brazilian Somali ram lambs with an average initial body weight of 13.47±1.76 kg. Eight animals were slaughtered at the trials beginning as a reference group to estimate the initial empty body weight (EBW and body composition. The remaining animals were assigned to a randomised block design with eight replications per block and five diets with increasing metabolisable energy content (4.93, 8.65, 9.41, 10.12 and 11.24 MJ/kg dry matter. The logarithm of heat production was regressed against metabolisable energy intake (MEI, and the NEm (kJ/kg0.75 EBW/day were estimated by extrapolation, when MEI was set at zero. The NEm was 239.77 kJ/kg0.75 EBW/day. The animal’s energy and EBW fat contents increased from 11.20 MJ/kg and 208.54 g/kg to 13.54 MJ/kg and 274.95 g/kg of EBW, respectively, as the BW increased from 13 to 28.70 kg. The net energy requirements for EBW gain increased from 13.79 to 16.72 MJ/kg EBW gain for body weights of 13 and 28.70 kg. Our study indicated the net energy requirements for maintenance in Brazilian Somali lambs were similar to the values commonly recommended by the United States’ nutritional system, but lower than the values recommended by Agricultural Research Council and Commonwealth Scientific and Industrial Research Organization. Net requirements for weight gain were less compared to the values commonly recommended by nutritional system of the United States.

Repulsive four-body interactions of α particles and quasistable nuclear α -particle condensates in heavy self-conjugate nuclei

Science.gov (United States)

Bai, Dong; Ren, Zhongzhou

2018-05-01

We study the effects of repulsive four-body interactions of α particles on nuclear α -particle condensates in heavy self-conjugate nuclei using a semianalytic approach, and find that the repulsive four-body interactions could decrease the critical number of α particles, beyond which quasistable α -particle condensate states can no longer exist, even if these four-body interactions make only tiny contributions to the total energy of the Hoyle-like state of 16O. Explicitly, we study eight benchmark parameter sets, and find that the critical number Ncr decreases by |Δ Ncr|˜1 -4 from Ncr˜11 with vanishing four-body interactions. We also discuss the effects of four-body interactions on energies and radii of α -particle condensates. Our study can be useful for future experiments to study α -particle condensates in heavy self-conjugate nuclei. Also, the experimental determination of Ncr will eventually help establish a better understanding on the α -particle interactions, especially the four-body interactions.

Global solutions to the electrodynamic two-body problem on a straight line

Science.gov (United States)

Bauer, G.; Deckert, D.-A.; Dürr, D.; Hinrichs, G.

2017-06-01

The classical electrodynamic two-body problem has been a long standing open problem in mathematics. For motion constrained to the straight line, the interaction is similar to that of the two-body problem of classical gravitation. The additional complication is the presence of unbounded state-dependent delays in the Coulomb forces due to the finiteness of the speed of light. This circumstance renders the notion of local solutions meaningless, and therefore, straightforward ODE techniques cannot be applied. Here, we study the time-symmetric case, i.e., the Fokker-Schwarzschild-Tetrode (FST) equations, comprising both advanced and retarded delays. We extend the technique developed in Deckert and Hinrichs (J Differ Equ 260:6900-6929, 2016), where existence of FST solutions was proven on the half line, to ensure global existence—a result that had been obtained by Bauer (Ein Existenzsatz für die Wheeler-Feynman-Elektrodynamik, Herbert Utz Verlag, München, 1997). Due to the novel technique, the presented proof is shorter and more transparent but also relies on the idea to employ asymptotic data to characterize solutions.

Comment on "Many-body localization in Ising models with random long-range interactions"

Science.gov (United States)

Maksymov, Andrii O.; Rahman, Noah; Kapit, Eliot; Burin, Alexander L.

2017-11-01

This Comment is dedicated to the investigation of many-body localization in a quantum Ising model with long-range power-law interactions r-α, relevant for a variety of systems ranging from electrons in Anderson insulators to spin excitations in chains of cold atoms. It has earlier been argued [arXiv:cond-mat/0611387 (2005); Phys. Rev. B 91, 094202 (2015), 10.1103/PhysRevB.91.094202] that this model obeys the dimensional constraint suggesting the delocalization of all finite-temperature states in the thermodynamic limit for α ≤2 d in a d -dimensional system. This expectation conflicts with the recent numerical studies of the specific interacting spin model of Li et al. [Phys. Rev. A 94, 063625 (2016), 10.1103/PhysRevA.94.063625]. To resolve this controversy we reexamine the model of Li et al. [Phys. Rev. A 94, 063625 (2016), 10.1103/PhysRevA.94.063625] and demonstrate that the infinite-temperature states there obey the dimensional constraint. The earlier developed scaling theory for the critical system size required for delocalization is extended to small exponents 0 ≤α ≤d . The disagreements between the two works are explained by the nonstandard selection of investigated states in the ordered phase in the work of Li et al. [Phys. Rev. A 94, 063625 (2016)type="doi" specific-use="suppress-display">10.1103/PhysRevA.94.063625].

Two-body density matrix for closed s-d shell nuclei

International Nuclear Information System (INIS)

Dimitrova, S.S.; Kadrev, D.N.; Antonov, A.N.; Stoitsov, M.V.

2000-01-01

The two-body density matrix for 4 He, 16 O and 40 Ca within the Low-order approximation of the Jastrow correlation method is considered. Closed analytical expressions for the two-body density matrix, the center of mass and relative local densities and momentum distributions are presented. The effects of the short-range correlations on the two-body nuclear characteristics are investigated. (orig.)

Computer simulation of the martensite transformation in a model two-dimensional body

International Nuclear Information System (INIS)

Chen, S.; Khachaturyan, A.G.; Morris, J.W. Jr.

1979-05-01

An analytical model of a martensitic transformation in an idealized body is constructed and used to carry out a computer simulation of the transformation in a pseudo-two-dimensional crystal. The reaction is assumed to proceed through the sequential transformation of elementary volumes (elementary martensitic particles, EMP) via the Bain strain. The elastic interaction between these volumes is computed and the transformation path chosen so as to minimize the total free energy. The model transformation shows interesting qualitative correspondencies with the known features of martensitic transformations in typical solids

Computer simulation of the martensite transformation in a model two-dimensional body

International Nuclear Information System (INIS)

Chen, S.; Khachaturyan, A.G.; Morris, J.W. Jr.

1979-06-01

An analytical model of a martensitic transformation in an idealized body is constructed and used to carry out a computer simulation of the transformation in a pseudo-two-dimensional crystal. The reaction is assumed to proceed through the sequential transformation of elementary volumes (elementary martensitic particles, EMP) via the Bain strain. The elastic interaction between these volumes is computed and the transformation path chosen so as to minimize the total free energy. The model transformation shows interesting qualitative correspondencies with the known features of martensitic transformations in typical solids

Exact results relating spin-orbit interactions in two-dimensional strongly correlated systems

Science.gov (United States)

Kucska, Nóra; Gulácsi, Zsolt

2018-06-01

A 2D square, two-bands, strongly correlated and non-integrable system is analysed exactly in the presence of many-body spin-orbit interactions via the method of Positive Semidefinite Operators. The deduced exact ground states in the high concentration limit are strongly entangled, and given by the spin-orbit coupling are ferromagnetic and present an enhanced carrier mobility, which substantially differs for different spin projections. The described state emerges in a restricted parameter space region, which however is clearly accessible experimentally. The exact solutions are provided via the solution of a matching system of equations containing 74 coupled, non-linear and complex algebraic equations. In our knowledge, other exact results for 2D interacting systems with spin-orbit interactions are not present in the literature.

Orbit determination with the two-body integrals: III

Science.gov (United States)

Gronchi, G. F.; Baù, G.; Marò, S.

2015-10-01

We present the results of our investigation on the use of the two-body integrals to compute preliminary orbits by linking too short arcs of observations of celestial bodies. This work introduces a significant improvement with respect to the previous papers on the same subject: Gronchi et al. (2010, 2011). Here we find a univariate polynomial equation of degree 9 in the radial distance ρ of the orbit at the mean epoch of one of the two arcs. This is obtained by a combination of the algebraic integrals of the two-body problem. Moreover, the elimination step, which in Gronchi et al. (2010, 2011) was done by resultant theory coupled with the discrete Fourier transform, is here obtained by elementary calculations. We also show some numerical tests to illustrate the performance of the new algorithm.

Dependence of four-body observables on the range of UPA-like effective interactions

International Nuclear Information System (INIS)

Perne, R.; Sandhas, W.

1977-07-01

A generalized unitary pole approximation (UPA) concerning the three-body amplitudes in the kernel of four-body integral equations is introduced. We furhtermore study the dependence of the 4 He binding energy and of four-body cross sections upon a position space cut-off parameter in the effective interactions. (orig.) [de

Industrial requirements for interactive product configurators

DEFF Research Database (Denmark)

Queva, Matthieu Stéphane Benoit; Probst, Christian W.; Vikkelsøe, Per

2009-01-01

The demand for highly customized products at low cost is driving the industry towards Mass Customization. Interactive product configurators play an essential role in this new trend, and must be able to support more and more complex features. The purpose of this paper is, firstly, to identify...... requirements for modern interactive configurators. Existing modeling and solving technologies for configuration are then reviewed and their limitations discussed. Finally, a proposition for a future product configuration system is described....

Transcriptome analysis of fat bodies from two brown planthopper (Nilaparvata lugens populations with different virulence levels in rice.

Directory of Open Access Journals (Sweden)

Haixin Yu

Full Text Available BACKGROUND: The brown planthopper (BPH, Nilaparvata lugens (Stål, one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population and Mudgo (M population. In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. CONCLUSIONS/SIGNIFICANCE: This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies

Transcriptome Analysis of Fat Bodies from Two Brown Planthopper (Nilaparvata lugens) Populations with Different Virulence Levels in Rice

Science.gov (United States)

Chen, Hongdan; Lai, Wenxiang; Fu, Qiang; Lou, Yonggen

2014-01-01

Background The brown planthopper (BPH), Nilaparvata lugens (Stål), one of the most serious rice insect pests in Asia, can quickly overcome rice resistance by evolving new virulent populations. The insect fat body plays essential roles in the life cycles of insects and in plant-insect interactions. However, whether differences in fat body transcriptomes exist between insect populations with different virulence levels and whether the transcriptomic differences are related to insect virulence remain largely unknown. Methodology/Principal Findings In this study, we performed transcriptome-wide analyses on the fat bodies of two BPH populations with different virulence levels in rice. The populations were derived from rice variety TN1 (TN1 population) and Mudgo (M population). In total, 33,776 and 32,332 unigenes from the fat bodies of TN1 and M populations, respectively, were generated using Illumina technology. Gene ontology annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology classifications indicated that genes related to metabolism and immunity were significantly active in the fat bodies. In addition, a total of 339 unigenes showed homology to genes of yeast-like symbionts (YLSs) from 12 genera and endosymbiotic bacteria Wolbachia. A comparative analysis of the two transcriptomes generated 7,860 differentially expressed genes. GO annotations and enrichment analysis of KEGG pathways indicated these differentially expressed transcripts might be involved in metabolism and immunity. Finally, 105 differentially expressed genes from YLSs and Wolbachia were identified, genes which might be associated with the formation of different virulent populations. Conclusions/Significance This study was the first to compare the fat-body transcriptomes of two BPH populations having different virulence traits and to find genes that may be related to this difference. Our findings provide a molecular resource for future investigations of fat bodies and will be useful

Heliosheath Space Environment Interactions with Icy Bodies in the Outermost Solar System

Science.gov (United States)

Cooper, John F.; Hill, Matthew E.; Richardson, John D.; Sturner, Steven J.

2006-01-01

The Voyager 1 and 2 spacecraft are exploring the space environment of the outermost solar system at the same time that earth-based astronomy continues to discover new icy bodies, one larger than Pluto, in the transitional region outward from the Classical Kuiper Belt to the Inner Oort Cloud. Some of the Scattered Disk Objects in this region periodically pass through the heliosheath, entered by Voyager 1 in Dec. 2004 and later expected to be reached by Voyager 2, and out even beyond the heliopause into the Very Local Interstellar Medium. The less energetic heliosheath ions, important for implantation and sputtering processes, are abundant near and beyond the termination shock inner boundary, but the source region of the more penetrating anomalous cosmic ray component has not yet been found. Advantageous for modeling of icy body interactions, the measured heliosheath flux spectra are relatively more stable within this new regime of isotropic compressional magnetic turbulence than in the upstream heliospheric environment. The deepest interactions and resultant radiation-induced chemistry arise from the inwardly diffusing component of the galactic cosmic ray ions with significant intensity modulation also arising in the heliosheath beyond Voyager 1. Surface gardening by high-velocity impacts of smaller bodies (e.g., fragments of previous KBO collisions) and dust is a further space weathering process setting the time scales for long term exposure of different regolith layers to the ion irradiation. Sputtering and ionization of impact ejecta grains may provide a substantial feedback of pickup ions for multiple cycles of heliosheath acceleration and icy body interaction. Thus the space weathering interactions are potentially of interest not only for effects on sensible surface composition of the icy bodies but also for evolution of the heliosheath plasma energetic ion, and neutral emission environment.

Vibrotactile masking through the body.

Science.gov (United States)

D'Amour, Sarah; Harris, Laurence R

2014-09-01

Touches on one hand or forearm can affect tactile sensitivity at contralateral locations on the opposite side of the body. These interactions suggest an intimate connection between the two sides of the body. Here, we explore the effect of masking not across the body but through the body by measuring the effect of a masking stimulus on the back on the tactile sensitivity of the corresponding point on the front. Tactile sensitivity was measured on each side of the stomach, while vibrotactile masking stimulation was applied to one side of the front and to points on the back including the point directly behind the test point on the front. Results were compared to sensitivity, while vibrotactile stimulation was applied to a control site on the shoulder. A reduction in sensitivity of about .8 dB was found that required the masking stimulus to be within about 2 cm of the corresponding point on the back.

Autophagy-Associated Protein SmATG12 Is Required for Fruiting-Body Formation in the Filamentous Ascomycete Sordaria macrospora.

Science.gov (United States)

Werner, Antonia; Herzog, Britta; Frey, Stefan; Pöggeler, Stefanie

2016-01-01

In filamentous fungi, autophagy functions as a catabolic mechanism to overcome starvation and to control diverse developmental processes under normal nutritional conditions. Autophagy involves the formation of double-membrane vesicles, termed autophagosomes that engulf cellular components and bring about their degradation via fusion with vacuoles. Two ubiquitin-like (UBL) conjugation systems are essential for the expansion of the autophagosomal membrane: the UBL protein ATG8 is conjugated to the lipid phosphatidylethanolamine and the UBL protein ATG12 is coupled to ATG5. We recently showed that in the homothallic ascomycete Sordaria macrospora autophagy-related genes encoding components of the conjugation systems are required for fruiting-body development and/or are essential for viability. In the present work, we cloned and characterized the S. macrospora (Sm)atg12 gene. Two-hybrid analysis revealed that SmATG12 can interact with SmATG7 and SmATG3. To examine its role in S. macrospora, we replaced the open reading frame of Smatg12 with a hygromycin resistance cassette and generated a homokaryotic ΔSmatg12 knockout strain, which displayed slower vegetative growth under nutrient starvation conditions and was unable to form fruiting bodies. In the hyphae of S. macrospora EGFP-labeled SmATG12 was detected in the cytoplasm and as punctate structures presumed to be phagophores or phagophore assembly sites. Delivery of EGFP-labelled SmATG8 to the vacuole was entirely dependent on SmATG12.

Autophagy-Associated Protein SmATG12 Is Required for Fruiting-Body Formation in the Filamentous Ascomycete Sordaria macrospora.

Directory of Open Access Journals (Sweden)

Antonia Werner

Full Text Available In filamentous fungi, autophagy functions as a catabolic mechanism to overcome starvation and to control diverse developmental processes under normal nutritional conditions. Autophagy involves the formation of double-membrane vesicles, termed autophagosomes that engulf cellular components and bring about their degradation via fusion with vacuoles. Two ubiquitin-like (UBL conjugation systems are essential for the expansion of the autophagosomal membrane: the UBL protein ATG8 is conjugated to the lipid phosphatidylethanolamine and the UBL protein ATG12 is coupled to ATG5. We recently showed that in the homothallic ascomycete Sordaria macrospora autophagy-related genes encoding components of the conjugation systems are required for fruiting-body development and/or are essential for viability. In the present work, we cloned and characterized the S. macrospora (Smatg12 gene. Two-hybrid analysis revealed that SmATG12 can interact with SmATG7 and SmATG3. To examine its role in S. macrospora, we replaced the open reading frame of Smatg12 with a hygromycin resistance cassette and generated a homokaryotic ΔSmatg12 knockout strain, which displayed slower vegetative growth under nutrient starvation conditions and was unable to form fruiting bodies. In the hyphae of S. macrospora EGFP-labeled SmATG12 was detected in the cytoplasm and as punctate structures presumed to be phagophores or phagophore assembly sites. Delivery of EGFP-labelled SmATG8 to the vacuole was entirely dependent on SmATG12.

Interaction of convective flow generated by human body with room ventilation flow: impact on transport of pollution to the breathing zone

DEFF Research Database (Denmark)

Licina, Dusan; Melikov, Arsen Krikor; Sekhar, Chandra

2014-01-01

interaction with opposing flow from above and assisting flow from below; and secondly, implication of such a flow interaction on the particle transport from the feet to the breathing zone is examined. The results reveal that the human body heat transports the pollution to the breathing zone and increases......This study aims to investigate the interaction between the human convective boundary layer (CBL) and uniform airflow from two directions and with different velocities. The study has two objectives: first, to characterize the velocity field in the breathing zone of a thermal manikin under its...

Monte Carlo calculations of few-body and light nuclei

International Nuclear Information System (INIS)

Wiringa, R.B.

1992-01-01

A major goal in nuclear physics is to understand how nuclear structure comes about from the underlying interactions between nucleons. This requires modelling nuclei as collections of strongly interacting particles. Using realistic nucleon-nucleon potentials, supplemented with consistent three-nucleon potentials and two-body electroweak current operators, variational Monte Carlo methods are used to calculate nuclear ground-state properties, such as the binding energy, electromagnetic form factors, and momentum distributions. Other properties such as excited states and low-energy reactions are also calculable with these methods

An Advanced N -body Model for Interacting Multiple Stellar Systems

Energy Technology Data Exchange (ETDEWEB)

Brož, Miroslav [Astronomical Institute of the Charles University, Faculty of Mathematics and Physics, V Holešovičkách 2, CZ-18000 Praha 8 (Czech Republic)

2017-06-01

We construct an advanced model for interacting multiple stellar systems in which we compute all trajectories with a numerical N -body integrator, namely the Bulirsch–Stoer from the SWIFT package. We can then derive various observables: astrometric positions, radial velocities, minima timings (TTVs), eclipse durations, interferometric visibilities, closure phases, synthetic spectra, spectral energy distribution, and even complete light curves. We use a modified version of the Wilson–Devinney code for the latter, in which the instantaneous true phase and inclination of the eclipsing binary are governed by the N -body integration. If all of these types of observations are at one’s disposal, a joint χ {sup 2} metric and an optimization algorithm (a simplex or simulated annealing) allow one to search for a global minimum and construct very robust models of stellar systems. At the same time, our N -body model is free from artifacts that may arise if mutual gravitational interactions among all components are not self-consistently accounted for. Finally, we present a number of examples showing dynamical effects that can be studied with our code and we discuss how systematic errors may affect the results (and how to prevent this from happening).

Interaction study of rice stripe virus proteins reveals a region of the nucleocapsid protein (NP) required for NP self-interaction and nuclear localization.

Science.gov (United States)

Lian, Sen; Cho, Won Kyong; Jo, Yeonhwa; Kim, Sang-Min; Kim, Kook-Hyung

2014-04-01

Rice stripe virus (RSV), which belongs to the genus Tenuivirus, is an emergent virus problem. The RSV genome is composed of four single-strand RNAs (RNA1-RNA4) and encodes seven proteins. We investigated interactions between six of the RSV proteins by yeast-two hybrid (Y2H) assay in vitro and by bimolecular fluorescence complementation (BiFC) in planta. Y2H identified self-interaction of the nucleocapsid protein (NP) and NS3, while BiFC revealed self-interaction of NP, NS3, and NCP. To identify regions(s) and/or crucial amino acid (aa) residues required for NP self-interaction, we generated various truncated and aa substitution mutants. Y2H assay showed that the N-terminal region of NP (aa 1-56) is necessary for NP self-interaction. Further analysis with substitution mutants demonstrated that additional aa residues located at 42-47 affected their interaction with full-length NP. These results indicate that the N-terminal region (aa 1-36 and 42-47) is required for NP self-interaction. BiFC and co-localization studies showed that the region required for NP self-interaction is also required for NP localization at the nucleus. Overall, our results indicate that the N-terminal region (aa 1-47) of the NP is important for NP self-interaction and that six aa residues (42-47) are essential for both NP self-interaction and nuclear localization. Copyright © 2014 Elsevier B.V. All rights reserved.

Bound states and scattering lengths of three two-component particles with zero-range interactions under one-dimensional confinement

International Nuclear Information System (INIS)

Kartavtsev, O.I.; Malykh, A.V.; Sofianos, S.A.

2008-01-01

The universal three-body dynamics in ultracold binary gases confined to one-dimensional motion is studied. The three-body binding energies and the (2+1)-scattering lengths are calculated for two identical particles of mass m and a different one of mass m 1 , between which interactions are described in the low-energy limit by zero-range potentials. The critical values of the mass ratio m/m 1 , at which the three-body states arise and the (2+1)-scattering length equals zero, are determined both for zero and infinite interaction strength λ 1 of the identical particles. A number of exact results are enlisted and asymptotic dependences both for m/m 1 → infinity and λ 1 → -infinity are derived. Combining the numerical and analytical results, a schematic diagram showing the number of the three-body bound states and the sign of the (2+1)-scattering length in the plane of the mass ratio and interaction-strength ratio is deduced. The results provide a description of the homogeneous and mixed phases of atoms and molecules in dilute binary quantum gases

Many-Body Theory for Positronium-Atom Interactions

Science.gov (United States)

Green, D. G.; Swann, A. R.; Gribakin, G. F.

2018-05-01

A many-body-theory approach has been developed to study positronium-atom interactions. As first applications, we calculate the elastic scattering and momentum-transfer cross sections and the pickoff annihilation rate 1Zeff for Ps collisions with He and Ne. For He the cross section is in agreement with previous coupled-state calculations, while comparison with experiment for both atoms highlights discrepancies between various sets of measured data. In contrast, the calculated 1Zeff (0.13 and 0.26 for He and Ne, respectively) are in excellent agreement with the measured values.

Three-body unitary transformations, three-body forces, and trinucleon bound state properties

International Nuclear Information System (INIS)

Haftel, M.I.

1976-01-01

A three-body unitary transformation method for the study of three-body forces is presented. Starting with a three-body Hamiltonian with two-body forces, unitary transformations are introduced to generate Hamiltonians that have both two- and three-body forces. For cases of physical interest, the two-body forces of the altered Hamiltonians are phase equivalent (for two-body scattering) to the original and the three-body force vanishes when any interparticle distance is large. Specific examples are presented. Applications for studying the possible role of three-body forces in accounting for trinucleon bound state properties are examined. Calculations of the 3 He and 3 H charge form factors and Coulomb energy difference with hyperspherical radial transformations and with conventional N-N potentials are performed. The form factor calculations demonstrate how the proposed method can help obtain improved agreement with experiment by the introduction of appropriate three-body forces. Calculations of the Coulomb energy difference confirm previous estimates concerning charge symmetry breaking in the N-N interaction

TRIM5α association with cytoplasmic bodies is not required for antiretroviral activity

International Nuclear Information System (INIS)

Song, Byeongwoon; Diaz-Griffero, Felipe; Park, Do Hyun; Rogers, Thomas; Stremlau, Matthew; Sodroski, Joseph

2005-01-01

The tripartite motif (TRIM) protein, TRIM5α, restricts infection by particular retroviruses. Many TRIM proteins form cytoplasmic bodies of unknown function. We investigated the relationship between cytoplasmic body formation and the structure and antiretroviral activity of TRIM5α. In addition to diffuse cytoplasmic staining, the TRIM5α proteins from several primate species were located in cytoplasmic bodies of different sizes; by contrast, TRIM5α from spider monkeys did not form cytoplasmic bodies. Despite these differences, all of the TRIM5α proteins exhibited the ability to restrict infection by particular retroviruses. Treatment of cells with geldanamycin, an Hsp90 inhibitor, resulted in disappearance or reduction of the TRIM5α-associated cytoplasmic bodies, yet exerted little effect on the restriction of retroviral infection. Studies of green fluorescent protein-TRIM5α fusion proteins indicated that no TRIM5α domain is specifically required for association with cytoplasmic bodies. Apparently, the formation of cytoplasmic bodies is not required for the antiretroviral activity of TRIM5α

DISCO interacting protein 2 determines direction of axon projection under the regulation of c-Jun N-terminal kinase in the Drosophila mushroom body

International Nuclear Information System (INIS)

Nitta, Yohei; Sugie, Atsushi

2017-01-01

Precisely controlled axon guidance for complex neuronal wiring is essential for appropriate neuronal function. c-Jun N-terminal kinase (JNK) was found to play a role in axon guidance recently as well as in cell proliferation, protection and apoptosis. In spite of many genetic and molecular studies on these biological processes regulated by JNK, how JNK regulates axon guidance accurately has not been fully explained thus far. To address this question, we use the Drosophila mushroom body (MB) as a model since the α/β axons project in two distinct directions. Here we show that DISCO interacting protein 2 (DIP2) is required for the accurate direction of axonal guidance. DIP2 expression is under the regulation of Basket (Bsk), the Drosophila homologue of JNK. We additionally found that the Bsk/DIP2 pathway is independent from the AP-1 transcriptional factor complex pathway, which is directly activated by Bsk. In conclusion, our findings revealed DIP2 as a novel effector downstream of Bsk modulating the direction of axon projection. - Highlights: • DIP2 is required for accurate direction of axon guidance in Drosophila mushroom body. • DIP2 is a downstream of JNK in the axon guidance of Drosophila mushroom body neuron. • JNK/DIP2 pathway is independent from JNK/AP-1 transcriptional factor complex pathway.

Two Equals One: Two Human Actions During Social Interaction Are Grouped as One Unit in Working Memory.

Science.gov (United States)

Ding, Xiaowei; Gao, Zaifeng; Shen, Mowei

2017-09-01

Every day, people perceive other people performing interactive actions. Retaining these actions of human agents in working memory (WM) plays a pivotal role in a normal social life. However, whether the semantic knowledge embedded in the interactive actions has a pervasive impact on the storage of the actions in WM remains unknown. In the current study, we investigated two opposing hypotheses: (a) that WM stores the interactions individually (the individual-storage hypothesis) and (b) that WM stores the interactions as chunks (the chunk-storage hypothesis). We required participants to memorize a set of individual actions while ignoring the underlying social interactions. We found that although the social-interaction aspect was task irrelevant, the interactive actions were stored in WM as chunks that were not affected by memory load (Experiments 1 and 2); however, inverting the human actions vertically abolished this chunking effect (Experiment 3). These results suggest that WM automatically and efficiently used semantic knowledge about interactive actions to store them and support the chunk-storage hypothesis.

Continuous atom laser with Bose-Einstein condensates involving three-body interactions

Energy Technology Data Exchange (ETDEWEB)

Carpentier, A V; Michinel, H; Novoa, D [Area de Optica, Facultade de Ciencias de Ourense, Universidade de Vigo, As Lagoas s/n, Ourense, ES-32004 (Spain); Olivieri, D N, E-mail: avcarpentier@uvigo.e [Area de Linguaxes e sistemas informaticos, Escola Superior de EnxenerIa Informatica, Universidade de Vigo, As Lagoas s/n, Ourense, ES-32004 (Spain)

2010-05-28

We demonstrate, through numerical simulations, the emission of a coherent continuous matter wave of constant amplitude from a Bose-Einstein condensate in a shallow optical dipole trap. The process is achieved by spatial control of the variations of the scattering length along the trapping axis, including elastic three-body interactions due to dipole interactions. In our approach, the outcoupling mechanism is atomic interactions, and thus, the trap remains unaltered. We calculate analytically the parameters for the experimental implementation of this continuous wave atom laser.

Visual capture and the experience of having two bodies – Evidence from two different virtual reality techniques

Directory of Open Access Journals (Sweden)

Lukas eHeydrich

2013-12-01

Full Text Available In neurology and psychiatry the detailed study of illusory own body perceptions has suggested close links between bodily processing and self-consciousness. One such illusory own body perception is heautoscopy where patients have the sensation of being reduplicated and to exist at two or even more locations. In previous experiments, using a video head-mounted display, self-location and self-identification were manipulated by applying conflicting visuo-tactile information. Yet the experienced singularity of the self was not affected, i.e. participants did not experience having multiple bodies or selves. In two experiments presented in this paper, we investigated self-location and self-identification while participants saw two virtual bodies (video-generated in study 1 and 3D computer generated in study 2 that were stroked either synchronously or asynchronously with their own body. In both experiments, we report that self-identification with two virtual bodies was stronger during synchronous stroking. Furthermore, in the video generated setup with synchronous stroking participants reported a greater feeling of having multiple bodies than in the control conditions. In study 1, but not in study 2, we report that self-location – measured by anterior posterior drift – was significantly shifted towards the two bodies in the synchronous condition only. Self-identification with two bodies, the sensation of having multiple bodies, and the changes in self-location show that the experienced singularity of the self can be studied experimentally. We discuss our data with respect to ownership for supernumerary hands and heautoscopy. We finally compare the effects of the video and 3D computer generated head-mounted display technology and discuss the possible benefits of using either technology to induce changes in illusory self-identification with a virtual body.

Proximity Interactions among Basal Body Components in Trypanosoma brucei Identify Novel Regulators of Basal Body Biogenesis and Inheritance

Directory of Open Access Journals (Sweden)

Hung Quang Dang

2017-01-01

Full Text Available The basal body shares similar architecture with centrioles in animals and is involved in nucleating flagellar axonemal microtubules in flagellated eukaryotes. The early-branching Trypanosoma brucei possesses a motile flagellum nucleated from the basal body that consists of a mature basal body and an adjacent pro-basal body. Little is known about the basal body proteome and its roles in basal body biogenesis and flagellar axoneme assembly in T. brucei. Here, we report the identification of 14 conserved centriole/basal body protein homologs and 25 trypanosome-specific basal body proteins. These proteins localize to distinct subdomains of the basal body, and several of them form a ring-like structure surrounding the basal body barrel. Functional characterization of representative basal body proteins revealed distinct roles in basal body duplication/separation and flagellar axoneme assembly. Overall, this work identified novel proteins required for basal body duplication and separation and uncovered new functions of conserved basal body proteins in basal body duplication and separation, highlighting an unusual mechanism of basal body biogenesis and inheritance in this early divergent eukaryote.

Poly (ADP-ribose polymerase 1 is required for protein localization to Cajal body.

Directory of Open Access Journals (Sweden)

Elena Kotova

2009-02-01

Full Text Available Recently, the nuclear protein known as Poly (ADP-ribose Polymerase1 (PARP1 was shown to play a key role in regulating transcription of a number of genes and controlling the nuclear sub-organelle nucleolus. PARP1 enzyme is known to catalyze the transfer of ADP-ribose to a variety of nuclear proteins. At present, however, while we do know that the main acceptor for pADPr in vivo is PARP1 protein itself, by PARP1 automodification, the significance of PARP1 automodification for in vivo processes is not clear. Therefore, we investigated the roles of PARP1 auto ADP-ribosylation in dynamic nuclear processes during development. Specifically, we discovered that PARP1 automodification is required for shuttling key proteins into Cajal body (CB by protein non-covalent interaction with pADPr in vivo. We hypothesize that PARP1 protein shuttling follows a chain of events whereby, first, most unmodified PARP1 protein molecules bind to chromatin and accumulate in nucleoli, but then, second, upon automodification with poly(ADP-ribose, PARP1 interacts non-covalently with a number of nuclear proteins such that the resulting protein-pADPr complex dissociates from chromatin into CB.

An Open Platform for Full Body Interactive Sonification Exergames

Directory of Open Access Journals (Sweden)

Simone Ghisio

2015-08-01

Full Text Available This paper addresses the use of a remote interactive platform to support home-based rehabilitation for children with motor and cognitive impairment. The interaction between user and platform is achieved on customizable full-body interactive serious games (exergames. These exergames perform real-time analysis of multimodal signals to quantify movement qualities and postural attitudes. Interactive sonification of movement is then applied for providing a real-time feedback based on “aesthetic resonance” and engagement of the children. The games also provide log file recordings therapists can use to assess the performance of the children and the effectiveness of the games. The platform allows the customization of the games to address the children’s needs. The platform is based on the EyesWeb XMI software, and the games are designed for home usage, based on Kinect for Xbox One and simple sensors including 3-axis accelerometers available in low-cost Android smartphones.

Contact point generation for convex polytopes in interactive rigid body dynamics

DEFF Research Database (Denmark)

Silcowitz-Hansen, Morten; Abel, Sarah Maria Niebe; Erleben, Kenny

When computing contact forces in rigid body dynamics systems, most state-of-the-art solutions use iterative methods such as the projected Gauss–Seidel (PGS) method. Methods such as the PGS method are preferred for their robustness. However, the time-critical nature of interactive applications...... combined with the linear convergence rates of such methods, will often result in visual artifacts in the final simulation. With this paper, we address an issue which is of major impact on the animation quality, when using methods such as the PGS method. The issue is robust generation of contact points...... for convex polytopes. A novel contact point generation method is presented, which is based on growth distances and Gauss maps. We demonstrate improvements when using our method in the context of interactive rigid body simulation...

Effective two-body equations for the four-body problem with exact treatment of (2+2)-subsystem contributions

International Nuclear Information System (INIS)

Haberzettl, H.; Sandhas, W.

1981-01-01

Noclear reactions: Four-body problem. Effective two-body equations with exact (2+2)-subsystem contributions. Relation to field-theoretical model by Fonseca and Shanley. Three-body propagator with exchange effects. (orig.)

Fournier gangrene from a thirty-two-centimeter rectosigmoid foreign body.

Science.gov (United States)

Abate, Getahun; Shirin, Mazumder; Kandanati, Vivek

2013-02-01

Medical and surgical problems associated with rectal foreign bodies are rare. Although most rectal foreign bodies can be removed without subsequent sequelae, they pose significant risk of infection. We report a patient with a 32-cm rectosigmoid foreign body and subsequent development of Fournier gangrene despite successful removal of the foreign body. A 63-year-old Caucasian man with past medical history of diabetes mellitus and depression presented with a chief complaint of "something stuck in my intestine." He admitted that he placed a foreign body in the rectum. Abdominal X-ray study and computed tomography of the abdomen/pelvis showed a conical-shaped 32-cm rectosigmoid foreign body. The foreign body was removed manually and follow-up colonoscopy was done. The patient's condition deteriorated in the first 2 days of hospital stay and he was diagnosed with Fournier gangrene. He required multiple surgeries and received broad-spectrum antibiotic coverage for mixed bacterial flora grown from deep tissue. Rectal foreign bodies can cause Fournier gangrene. A close observation and follow-up is important after removal of rectal foreign bodies. Published by Elsevier Inc.

H(+) - O(+) two-stream interaction on auroral field lines

International Nuclear Information System (INIS)

Bergmann, R.

1990-01-01

Upflowing beams of hydrogen, oxygen, and minor ion species, and downward accelerated electrons have been observed above several thousand kilometers altitude on evening auroral field lines. The mechanism for electron and ion acceleration is generally accepted to be the presence of a quasi-static electric field with a component parallel to the earth's magnetic field. The thermal energy of the observed beams is much larger than ionospheric ion temperatures indicating that the beams have been heated as they are accelerated upward. This heating is probably due to a two-stream interaction between beams of different mass ions. The beams gain equal energy in the potential drop and so have different average velocities. Their relative streaming initiates an ion-ion two-stream interaction which then mediates a transfer of energy and momentum between the beams and causes thermalization of each beam. The qualitative evidence that supports this scenario is reviewed. Properties of the two-stream instability are presented in order to demonstrate that a calculation of the evolution of ion beams requires a model that includes field-aligned spatial structure. 26 refs

Extended two-particle Green close-quote s functions and optical potentials for two particle scattering by by many-body targets

International Nuclear Information System (INIS)

Brand, J.; Cederbaum, L.S.

1996-01-01

An extension of the fermionic particle-particle propagator is presented that possesses similar algebraic properties to the single-particle Green close-quote s function. In particular, this extended two-particle Green close-quote s function satisfies Dyson close-quote s equation and its self energy has the same analytic structure as the self energy of the single-particle Green close-quote s function. For the case of a system interacting with one-particle potentials only, the two-particle self energy takes on a particularly simple form, just like the common self energy does. The new two-particle self energy also serves as a well behaved optical potential for the elastic scattering of a two-particle projectile by a many-body target. Due to its analytic structure, the two-particle self energy avoids divergences that appear with effective potentials derived by other means. Copyright copyright 1996 Academic Press, Inc

Requirements for user interaction support in future CACE environments

DEFF Research Database (Denmark)

Ravn, Ole; Szymkat, M.

1994-01-01

Based on a review of user interaction modes and the specific needs of the CACE domain the paper describes requirements for user interaction in future CACE environments. Taking another look at the design process in CACE key areas in need of more user interaction support are pointed out. Three...

Probing quantum and thermal noise in an interacting many-body system

DEFF Research Database (Denmark)

Hofferberth, S.; Lesanovsky, Igor; Schumm, Thorsten

2008-01-01

of the shot-to-shot variations of interference-fringe contrast for pairs of independently created one-dimensional Bose condensates. Analysing different system sizes, we observe the crossover from thermal to quantum noise, reflected in a characteristic change in the distribution functions from poissonian......The probabilistic character of the measurement process is one of the most puzzling and fascinating aspects of quantum mechanics. In many-body systems quantum-mechanical noise reveals non-local correlations of the underlying many-body states. Here, we provide a complete experimental analysis....... Furthermore, our experiments constitute the first analysis of the full distribution of quantum noise in an interacting many-body system....

Vestibular-somatosensory interactions: effects of passive whole-body rotation on somatosensory detection.

Directory of Open Access Journals (Sweden)

Elisa Raffaella Ferrè

Full Text Available Vestibular signals are strongly integrated with information from several other sensory modalities. For example, vestibular stimulation was reported to improve tactile detection. However, this improvement could reflect either a multimodal interaction or an indirect interaction driven by vestibular effects on spatial attention and orienting. Here we investigate whether natural vestibular activation induced by passive whole-body rotation influences tactile detection. In particular, we assessed the ability to detect faint tactile stimuli to the fingertips of the left and right hand during spatially congruent or incongruent rotations. We found that passive whole-body rotations significantly enhanced sensitivity to faint shocks, without affecting response bias. Critically, this enhancement of somatosensory sensitivity did not depend on the spatial congruency between the direction of rotation and the hand stimulated. Thus, our results support a multimodal interaction, likely in brain areas receiving both vestibular and somatosensory signals.

Two is better than one: Physical interactions improve motor performance in humans

Science.gov (United States)

Ganesh, G.; Takagi, A.; Osu, R.; Yoshioka, T.; Kawato, M.; Burdet, E.

2014-01-01

How do physical interactions with others change our own motor behavior? Utilizing a novel motor learning paradigm in which the hands of two - individuals are physically connected without their conscious awareness, we investigated how the interaction forces from a partner adapt the motor behavior in physically interacting humans. We observed the motor adaptations during physical interactions to be mutually beneficial such that both the worse and better of the interacting partners improve motor performance during and after interactive practice. We show that these benefits cannot be explained by multi-sensory integration by an individual, but require physical interaction with a reactive partner. Furthermore, the benefits are determined by both the interacting partner's performance and similarity of the partner's behavior to one's own. Our results demonstrate the fundamental neural processes underlying human physical interactions and suggest advantages of interactive paradigms for sport-training and physical rehabilitation.

Some general features of two body reactions in K{sup -}p interactions at 3 GeV/c; Quelques proprietes des reactions a deux corps dans les interactions K{sup -}p a 3 GeV/c

Energy Technology Data Exchange (ETDEWEB)

Badier, J; Demoulin, M; Goldberg, J [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); and others

1966-06-01

The differential and total cross sections of two-body reactions produced in 3 GeV/c K{sup -} proton collisions are presented. Their variation as a function of the baryonic number, strangeness, and isospin of the t and u cross channels is analyzed, as well as some implications of a baryon exchange mechanism. (authors) [French] Ce travail presente les sections efficaces differentielle et totale des reactions 'deux corps' produites par les interactions K{sup -}p a 3 GeV/c. Nous analysons leurs variations en fonction du nombre baryonique, de l'etrangete et de l'isospin des voies croisees t et u. Quelques consequences de l'hypothese de l'echange d'un baryon sont etudiees. (auteurs)

Density-functional approach to the three-body dispersion interaction based on the exchange dipole moment

Energy Technology Data Exchange (ETDEWEB)

Proynov, Emil; Wang, Matthew; Kong, Jing, E-mail: jing.kong@mtsu.edu [Department of Chemistry and Center for Computational Sciences, Middle Tennessee State University, Murfreesboro, Tennessee 37132 (United States); Liu, Fenglai [Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, New York 14260 (United States); Gan, Zhengting [Q-Chem Inc., 5001 Baum Boulevard, Pittsburgh, Pennsylvania 15213 (United States)

2015-08-28

We implement and compute the density functional nonadditive three-body dispersion interaction using a combination of Tang-Karplus formalism and the exchange-dipole moment model of Becke and Johnson. The computation of the C{sub 9} dispersion coefficients is done in a non-empirical fashion. The obtained C{sub 9} values of a series of noble atom triplets agree well with highly accurate values in the literature. We also calculate the C{sub 9} values for a series of benzene trimers and find a good agreement with high-level ab initio values reported recently in the literature. For the question of damping of the three-body dispersion at short distances, we propose two damping schemes and optimize them based on the benzene trimers data, and the fitted analytic potentials of He{sub 3} and Ar{sub 3} trimers fitted to the results of high-level wavefunction theories available from the literature. Both damping schemes respond well to the optimization of two parameters.

Does parental divorce moderate the heritability of body dissatisfaction? An extension of previous gene-environment interaction effects.

Science.gov (United States)

O'Connor, Shannon M; Klump, Kelly L; VanHuysse, Jessica L; McGue, Matt; Iacono, William

2016-02-01

Previous research suggests that parental divorce moderates genetic influences on body dissatisfaction. Specifically, the heritability of body dissatisfaction is higher in children of divorced versus intact families, suggesting possible gene-environment interaction effects. However, prior research is limited to a single, self-reported measure of body dissatisfaction. The primary aim of this study was to examine whether these findings extend to a different dimension of body dissatisfaction: body image perceptions. Participants were 1,534 female twins from the Minnesota Twin Family Study, aged 16-20 years. The Body Rating Scale (BRS) was used to assess body image perceptions. Although BRS scores were heritable in twins from divorced and intact families, the heritability estimates in the divorced group were not significantly greater than estimates in the intact group. However, there were differences in nonshared environmental effects, where the magnitude of these environmental influences was larger in the divorced as compared with the intact families. Different dimensions of body dissatisfaction (i.e., negative self-evaluation versus body image perceptions) may interact with environmental risk, such as parental divorce, in discrete ways. Future research should examine this possibility and explore differential gene-environment interactions using diverse measures. © 2015 Wiley Periodicals, Inc.

On The Dynamics and Design of a Two-body Wave Energy Converter

Science.gov (United States)

Liang, Changwei; Zuo, Lei

2016-09-01

A two-body wave energy converter oscillating in heave is studied in this paper. The energy is extracted through the relative motion between the floating and submerged bodies. A linearized model in the frequency domain is adopted to study the dynamics of such a two-body system with consideration of both the viscous damping and the hydrodynamic damping. The closed form solution of the maximum absorption power and corresponding power take-off parameters are obtained. The suboptimal and optimal designs for a two-body system are proposed based on the closed form solution. The physical insight of the optimal design is to have one of the damped natural frequencies of the two body system the same as, or as close as possible to, the excitation frequency. A case study is conducted to investigate the influence of the submerged body on the absorption power of a two-body system subjected to suboptimal and optimal design under regular and irregular wave excitations. It is found that the absorption power of the two-body system can be significantly higher than that of the single body system with the same floating buoy in both regular and irregular waves. In regular waves, it is found that the mass of the submerged body should be designed with an optimal value in order to achieve the maximum absorption power for the given floating buoy. The viscous damping on the submerged body should be as small as possible for a given mass in both regular and irregular waves.

Genotype x diet interactions in mice predisposed to mammary cancer. I. Body weight and fat

DEFF Research Database (Denmark)

Gordon, Ryan R; Hunter, Kent W; Sørensen, Peter

2008-01-01

a very-high-fat or a matched-control-fat diet and measured growth, body composition, age at mammary tumor onset, tumor number and severity, and formation of pulmonary metastases. SNP genotyping across the genome facilitated analyses of QTL and QTL x diet interaction effects. Here we describe development...... of the F(2) population (n = 615) which resulted from a cross between the polygenic obesity model M16i and FVB/NJ-TgN (MMTV-PyMT)(634Mul), effects of diet on growth and body composition, and QTL and QTL x diet and/or gender interaction effects for growth and obesity-related phenotypes. We identified 38 QTL...... for body composition traits that were significant at the genome-wide 0.05 level, likely representing nine distinct loci after accounting for pleiotropic effects. QTL x diet and/or gender interactions were present at 15 of these QTL, indicating that such interactions play a significant role in defining...

How bodies and voices interact in early emotion perception.

Science.gov (United States)

Jessen, Sarah; Obleser, Jonas; Kotz, Sonja A

2012-01-01

Successful social communication draws strongly on the correct interpretation of others' body and vocal expressions. Both can provide emotional information and often occur simultaneously. Yet their interplay has hardly been studied. Using electroencephalography, we investigated the temporal development underlying their neural interaction in auditory and visual perception. In particular, we tested whether this interaction qualifies as true integration following multisensory integration principles such as inverse effectiveness. Emotional vocalizations were embedded in either low or high levels of noise and presented with or without video clips of matching emotional body expressions. In both, high and low noise conditions, a reduction in auditory N100 amplitude was observed for audiovisual stimuli. However, only under high noise, the N100 peaked earlier in the audiovisual than the auditory condition, suggesting facilitatory effects as predicted by the inverse effectiveness principle. Similarly, we observed earlier N100 peaks in response to emotional compared to neutral audiovisual stimuli. This was not the case in the unimodal auditory condition. Furthermore, suppression of beta-band oscillations (15-25 Hz) primarily reflecting biological motion perception was modulated 200-400 ms after the vocalization. While larger differences in suppression between audiovisual and audio stimuli in high compared to low noise levels were found for emotional stimuli, no such difference was observed for neutral stimuli. This observation is in accordance with the inverse effectiveness principle and suggests a modulation of integration by emotional content. Overall, results show that ecologically valid, complex stimuli such as joined body and vocal expressions are effectively integrated very early in processing.

Structures of two-dimensional three-body systems

International Nuclear Information System (INIS)

Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.

1996-01-01

Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)

Spectrometer requirements for (e,e'2N) studies

International Nuclear Information System (INIS)

Lightbody, J.W. Jr.

1981-01-01

One specific experiment that may be performed with a future CW accelerator is a study of (e,e'2N) reactions through which we may learn details of the short range interaction of two nucleons within nuclear matter. It is suspected that the only mechanism which can lead to the observed high momentum components in the single nucleon momentum distribution (above approx. 400 MeV/c) inferred from (e,e'p) and (γ,p) measurements is the presence of short-range few-body correlations in the many-body nuclear wave function. It is expected that the explicit pair correlation function may be inferred from relative two-nucleon momentum distributions measured in (e,e'2N) experiments. It is therefore interesting to estimate counting rates using measured one-body momentum distributions to see what types of spectrometers are required

Comparison between calibration methods for in vivo monitoring in human body

International Nuclear Information System (INIS)

Mello, J.Q. de; Almeida, A.PF.; Dantas, A.L.A.; Hunt, J.G.; Dantas, B.M.

2014-01-01

The determination of photon emitters in the human body through in vivo measurements requires the use of specific techniques to obtain calibration factors which correlate count rates and activities present in the body. In the present work two methods were compared for the measurement of 40 K in whole body geometry with a scintillation detector type NaI(Tl)3x3: (1) experimental, using a BOMAB physical anthropomorphic phantom and (2) mathematical simulation of the phantom and the interaction of the photons with the detector. The results obtained show the equivalence between the methods in the geometry and energy conditions adopted in the experiment. (author)

Two-dimensional flow characteristics of wave interactions with a free-rolling rectangular structure

Energy Technology Data Exchange (ETDEWEB)

Kwang Hyo Jung; Kuang-An Chang [Texas A and M University, College Station, TX (United States). Dept. of Civil Engineering; Huang, E.T. [Naval Facilities Engineering Service Center, Port Hueneme, CA (United States). Amphibious System Div.

2005-01-01

This paper presents laboratory observations of flow characteristics for regular waves passing a rectangular structure in a two-dimensional wave tank. The structure with a draft one-half of its height was hinged at the center of gravity and free to roll (one degree of freedom) by waves. Particle image velocimetry (PIV) was used to measure the velocity field in the vicinity of the structure. The mean velocity and turbulence properties were obtained by phase-averaging the PIV velocity maps from repeated test runs. Since the viscous damping (also called the eddy making damping) in a vortical flow affects the roll motion of a blunt body, the quantitative flow pattern was represented to elucidate the coupled interactions between the body motion and the waves. Additionally, the turbulence properties including the turbulence length scale and the turbulent kinetic energy budget were investigated to characterize the interactions. The results show that vortices were generated near the structure corners at locations opposing to that of the roll damping effect for waves with a period longer than the roll natural period of the structure. (Author)

Chaos in body-vortex interactions

DEFF Research Database (Denmark)

Pedersen, Johan Rønby; Aref, Hassan

2010-01-01

of a circle is integrable. As the body is made slightly elliptic, a chaotic region grows from an unstable relative equilibrium of the circle-vortex case. The case of a cylindrical body of any shape moving in fluid otherwise at rest is also integrable. A second transition to chaos arises from the limit between...... rocking and tumbling motion of the body known in this case. In both instances, the chaos may be detected both in the body motion and in the vortex motion. The effect of increasing body mass at a fixed body shape is to damp the chaos....

Many Body Structure of Strongly Interacting Systems

CERN Document Server

Arenhövel, Hartmuth; Drechsel, Dieter; Friedrich, Jörg; Kaiser, Karl-Heinz; Walcher, Thomas; Symposium on 20 Years of Physics at the Mainz Microtron MAMI

2006-01-01

This carefully edited proceedings volume provides an extensive review and analysis of the work carried out over the past 20 years at the Mainz Microtron (MAMI). This research centered around the application of Quantum Chromodynamics in the strictly nonperturbative regime at hadronic scales of about 1 fm. Due to the many degrees of freedom in hadrons at this scale the leitmotiv of this research is "Many body structure of strongly interacting systems". Further, an outlook on the research with the forthcoming upgrade of MAMI is given. This volume is an authoritative source of reference for everyone interested in the field of the electro-weak probing of the structure of hadrons.

A bibliography of high energy two-body and inclusive scattering data

International Nuclear Information System (INIS)

Gault, F.D.; Read, B.J.; Roberts, R.G.

1977-09-01

A bibliography is presented of the data on high energy two-body and quasi-two-body final state scattering processes. This updated edition also covers one and two-particle inclusive production. It contains references to those published papers whose main purpose is to provide data on high energy two-body and inclusive hadronic scattering cross-sections rather than just properties of the produced particles. It covers the leading high energy physics journals and the period up to June 1977. The entries are grouped by process in the order indicated in the Table of Contents, and an author index is also provided. (author)

Investigation of Fanconi anemia protein interactions by yeast two-hybrid analysis.

Science.gov (United States)

Huber, P A; Medhurst, A L; Youssoufian, H; Mathew, C G

2000-02-05

Fanconi anemia is a chromosomal breakage disorder with eight complementation groups (A-H), and three genes (FANCA, FANCC, and FANCG) have been identified. Initial investigations of the interaction between FANCA and FANCC, principally by co-immunoprecipitation, have proved controversial. We used the yeast two-hybrid assay to test for interactions of the FANCA, FANCC, and FANCG proteins. No activation of the reporter gene was observed in yeast co-expressing FANCA and FANCC as hybrid proteins, suggesting that FANCA does not directly interact with FANCC. However, a high level of activation was found when FANCA was co-expressed with FANCG, indicating strong, direct interaction between these proteins. Both FANCA and FANCG show weak but consistent interaction with themselves, suggesting that their function may involve dimerisation. The site of interaction of FANCG with FANCA was investigated by analysis of 12 mutant fragments of FANCG. Although both N- and C-terminal fragments did interact, binding to FANCA was drastically reduced, suggesting that more than one region of the FANCG protein is required for proper interaction with FANCA. Copyright 2000 Academic Press.

Three-body halo nuclei in an effective theory framework

Energy Technology Data Exchange (ETDEWEB)

Canham, David L.

2009-05-20

The universal properties and structure of halo nuclei composed of two neutrons (2n) and a core are investigated within an effective quantum mechanics framework. We construct an effective interaction potential that exploits the separation of scales in halo nuclei and treat the nucleus as an effective three-body system, which to leading order is described by the large S-wave scattering lengths in the underlying two-body subsystems. The uncertainty from higher orders in the expansion is quantified through theoretical error bands. First, we investigate the possibility to observe excited Efimov states in 2n halo nuclei. Based on the experimental data, {sup 20}C is the only halo nucleus candidate to possibly have an Efimov excited state, with an energy less than 7 keV below the scattering threshold. Second, we study the structure of {sup 20}C and other 2n halo nuclei. In particular, we calculate their matter density form factors, radii, and two-neutron opening angles. We then make a systematic improvement upon these calculations by extending the effective potential to the next-to-leading order. To this order, we require an additional two-body parameter, which we tune to the effective range of the interaction. In addition to range corrections to the 2n halo nuclei results, we show corrections to the Efimov effect in the three-boson system. Furthermore, we explore universality in the linear range corrections to the Efimov spectrum. Finally, we study the scattering of D{sup 0} and D{sup *0} mesons and their antiparticles off the X(3872) in an effective field theory for short-range interactions. We present results for the S-wave scattering amplitude, total interaction cross section and S-wave scattering length. (orig.)

Three-body halo nuclei in an effective theory framework

International Nuclear Information System (INIS)

Canham, David L.

2009-01-01

The universal properties and structure of halo nuclei composed of two neutrons (2n) and a core are investigated within an effective quantum mechanics framework. We construct an effective interaction potential that exploits the separation of scales in halo nuclei and treat the nucleus as an effective three-body system, which to leading order is described by the large S-wave scattering lengths in the underlying two-body subsystems. The uncertainty from higher orders in the expansion is quantified through theoretical error bands. First, we investigate the possibility to observe excited Efimov states in 2n halo nuclei. Based on the experimental data, 20 C is the only halo nucleus candidate to possibly have an Efimov excited state, with an energy less than 7 keV below the scattering threshold. Second, we study the structure of 20 C and other 2n halo nuclei. In particular, we calculate their matter density form factors, radii, and two-neutron opening angles. We then make a systematic improvement upon these calculations by extending the effective potential to the next-to-leading order. To this order, we require an additional two-body parameter, which we tune to the effective range of the interaction. In addition to range corrections to the 2n halo nuclei results, we show corrections to the Efimov effect in the three-boson system. Furthermore, we explore universality in the linear range corrections to the Efimov spectrum. Finally, we study the scattering of D 0 and D *0 mesons and their antiparticles off the X(3872) in an effective field theory for short-range interactions. We present results for the S-wave scattering amplitude, total interaction cross section and S-wave scattering length. (orig.)

The Calculation of Single-Nucleon Energies of Nuclei by Considering Two-Body Effective Interaction, n(k,ρ, and a Hartree-Fock Inspired Scheme

Directory of Open Access Journals (Sweden)

H. Mariji

2016-01-01

Full Text Available The nucleon single-particle energies (SPEs of the selected nuclei, that is, O16, Ca40, and Ni56, are obtained by using the diagonal matrix elements of two-body effective interaction, which generated through the lowest-order constrained variational (LOCV calculations for the symmetric nuclear matter with the Aυ18 phenomenological nucleon-nucleon potential. The SPEs at the major levels of nuclei are calculated by employing a Hartree-Fock inspired scheme in the spherical harmonic oscillator basis. In the scheme, the correlation influences are taken into account by imposing the nucleon effective mass factor on the radial wave functions of the major levels. Replacing the density-dependent one-body momentum distribution functions of nucleons, n(k,ρ, with the Heaviside functions, the role of n(k,ρ in the nucleon SPEs at the major levels of the selected closed shell nuclei is investigated. The best fit of spin-orbit splitting is taken into account when correcting the major levels of the nuclei by using the parameterized Wood-Saxon potential and the Aυ18 density-dependent mean field potential which is constructed by the LOCV method. Considering the point-like protons in the spherical Coulomb potential well, the single-proton energies are corrected. The results show the importance of including n(k,ρ, instead of the Heaviside functions, in the calculation of nucleon SPEs at the different levels, particularly the valence levels, of the closed shell nuclei.

Proprioceptive Interaction between the Two Arms in a Single-Arm Pointing Task.

Directory of Open Access Journals (Sweden)

Kazuyoshi Kigawa

Full Text Available Proprioceptive signals coming from both arms are used to determine the perceived position of one arm in a two-arm matching task. Here, we examined whether the perceived position of one arm is affected by proprioceptive signals from the other arm in a one-arm pointing task in which participants specified the perceived position of an unseen reference arm with an indicator paddle. Both arms were hidden from the participant's view throughout the study. In Experiment 1, with both arms placed in front of the body, the participants received 70-80 Hz vibration to the elbow flexors of the reference arm (= right arm to induce the illusion of elbow extension. This extension illusion was compared with that when the left arm elbow flexors were vibrated or not. The degree of the vibration-induced extension illusion of the right arm was reduced in the presence of left arm vibration. In Experiment 2, we found that this kinesthetic interaction between the two arms did not occur when the left arm was vibrated in an abducted position. In Experiment 3, the vibration-induced extension illusion of one arm was fully developed when this arm was placed at an abducted position, indicating that the brain receives increased proprioceptive input from a vibrated arm even if the arm was abducted. Our results suggest that proprioceptive interaction between the two arms occurs in a one-arm pointing task when the two arms are aligned with one another. The position sense of one arm measured using a pointer appears to include the influences of incoming information from the other arm when both arms were placed in front of the body and parallel to one another.

Two-quasineutron states in 98248Cf and 98250Cf and the neutron-neutron residual interactions

International Nuclear Information System (INIS)

Katori, K.; Ahmad, I.; Friedman, A. M.

2008-01-01

Two-quasineutron states in 248 Cf and 250 Cf were investigated by single-neutron transfer reactions, 249 Cf(d,t) 248 Cf and 249 Cf(d,p) 250 Cf. The majority of levels observed were assigned to 12 bands in 248 Cf and six bands in 250 Cf, constructed from the single-particle states in neighboring Cf nuclei. The effective two-body interactions between two odd neutrons coupled outside a deformed core were deduced from the differences in the energies of the bandheads formed by the parallel and antiparallel coupling of the intrinsic spins of the two single-particle states

Coulomb-Sturmian separable expansion approach: Three-body Faddeev calculations for Coulomb-like interactions

International Nuclear Information System (INIS)

Papp, Z.; Plessas, W.

1996-01-01

We demonstrate the feasibility and efficiency of the Coulomb-Sturmian separable expansion method for generating accurate solutions of the Faddeev equations. Results obtained with this method are reported for several benchmark cases of bosonic and fermionic three-body systems. Correct bound-state results in agreement with the ones established in the literature are achieved for short-range interactions. We outline the formalism for the treatment of three-body Coulomb systems and present a bound-state calculation for a three-boson system interacting via Coulomb plus short-range forces. The corresponding result is in good agreement with the answer from a recent stochastic-variational-method calculation. copyright 1996 The American Physical Society

Body-part specific interactions of action verb processing with motor behaviour.

Science.gov (United States)

Klepp, Anne; Niccolai, Valentina; Sieksmeyer, Jan; Arnzen, Stephanie; Indefrey, Peter; Schnitzler, Alfons; Biermann-Ruben, Katja

2017-06-15

The interaction of action-related language processing with actual movement is an indicator of the functional role of motor cortical involvement in language understanding. This paper describes two experiments using single action verb stimuli. Motor responses were performed with the hand or the foot. To test the double dissociation of language-motor facilitation effects within subjects, Experiments 1 and 2 used a priming procedure where both hand and foot reactions had to be performed in response to different geometrical shapes, which were preceded by action verbs. In Experiment 1, the semantics of the verbs could be ignored whereas Experiment 2 included semantic decisions. Only Experiment 2 revealed a clear double dissociation in reaction times: reactions were facilitated when preceded by verbs describing actions with the matching effector. In Experiment 1, by contrast, there was an interaction between verb-response congruence and a semantic variable related to motor features of the verbs. Thus, the double dissociation paradigm of semantic motor priming was effective, corroborating the role of the motor system in action-related language processing. Importantly, this effect was body part specific. Copyright © 2017 Elsevier B.V. All rights reserved.

Interaction and activity coordination of territorial customs bodies of the State fiscal service of Ukraine with local state administrations and local self-government bodies

Directory of Open Access Journals (Sweden)

Олексій Павлович Федотов

2016-06-01

Based on the results of the study the author notes that the interaction of the Ukrainian SFS customs offices and local state administrations with local self-government bodies is an inherent quality, link and component of the Ukrainian SFS Customs offices functioning organization, which aims to improve the state customs service implementation standards by the Ukrainian SFS customs houses and to ensure the said implementation efficiency. However, in the course of interaction of the Ukrainian SFS customs with local state administrations and local self-government bodies each of the mentioned organizations specializes in solving their specific tasks in accordance with their subject expertise, and forms a clear organizational system. The complementarity of such kind helps to improve the state customs affairs conductance quality and is realized through the coordination of performance of the Ukrainian SFS customs offices, local state administrations and local self-government bodies as the interaction subjects through normative, informational and analytical provision for the interaction and concretization of the activities of each subject within the planned activities.

Quasi two-body decays of D0 meson

International Nuclear Information System (INIS)

Terasaki, K.; Oneda, S.

1985-08-01

Quasi two-body decays of D 0 -meson are studied from an algebraic approach, using a hard meson extrapolation. In this innovation of old current algebra with new perspective, a reasonable unified description of K sub(S) → 2π and D 0 → K-barπ decays has been obtained previously, keeping only the contribution of ground state mesons to the now surviving surface term. In this paper, it is shown that quasi two-body decays can also be accomodated reasonably well in the same scheme. A distinctive feature of our result is that GAMMA(D 0 → phi K-bar 0 ) is sizable, while D 0 → rho 0 K-bar 0 is relatively suppressed. (author)

Investigation of scattering processes in quantum few-body systems involving long-range interaction by the complex-rotation method

International Nuclear Information System (INIS)

Volkov, M. V.; Elander, N.; Yakovlev, S. L.; Yarevsky, E. A.

2013-01-01

The complex-rotation method adapted to solving the multichannel scattering problem in the two-body system where the interaction potential contains the long-range Coulomb components is described. The scattering problem is reformulated as the problem of solving a nonhomogeneous Schrödinger equation in which the nonhomogeneous term involves a Coulomb potential cut off at large distances. The incident wave appearing in the nonhomogeneous term is a solution of the Schrödinger equation with longrange Coulomb interaction. This formulation is free from approximations associated with a direct cutoff of Coulomb interaction at large distances. The efficiency of this formalism is demonstrated by considering the example of solving scattering problems in the α-α and p-p systems.

The translation initiation factor 3 subunit eIF3K interacts with PML and associates with PML nuclear bodies

Energy Technology Data Exchange (ETDEWEB)

Salsman, Jayme; Pinder, Jordan; Tse, Brenda [Department of Pathology, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2 (Canada); Corkery, Dale [Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia (Canada); Dellaire, Graham, E-mail: dellaire@dal.ca [Department of Pathology, Dalhousie University, P.O. Box 15000, Halifax, Nova Scotia, Canada B3H 4R2 (Canada); Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia (Canada)

2013-10-15

The promyelocytic leukemia protein (PML) is a tumor suppressor protein that regulates a variety of important cellular processes, including gene expression, DNA repair and cell fate decisions. Integral to its function is the ability of PML to form nuclear bodies (NBs) that serve as hubs for the interaction and modification of over 90 cellular proteins. There are seven canonical isoforms of PML, which encode diverse C-termini generated by alternative pre-mRNA splicing. Recruitment of specific cellular proteins to PML NBs is mediated by protein–protein interactions with individual PML isoforms. Using a yeast two-hybrid screen employing peptide sequences unique to PML isoform I (PML-I), we identified an interaction with the eukaryotic initiation factor 3 subunit K (eIF3K), and in the process identified a novel eIF3K isoform, which we term eIF3K-2. We further demonstrate that eIF3K and PML interact both in vitro via pull-down assays, as well as in vivo within human cells by co-immunoprecipitation and co-immunofluorescence. In addition, eIF3K isoform 2 (eIF3K-2) colocalizes to PML bodies, particularly those enriched in PML-I, while eIF3K isoform 1 associates poorly with PML NBs. Thus, we report eIF3K as the first known subunit of the eIF3 translation pre-initiation complex to interact directly with the PML protein, and provide data implicating alternative splicing of both PML and eIF3K as a possible regulatory mechanism for eIF3K localization at PML NBs. - Highlights: • The PML-I C-terminus, encoded by exon 9, interacts with translation factor eIF3K. • We identify a novel eIF3K isoform that excludes exon 2 (eIF3K-2). • eIF3K-2 preferentially associates with PML bodies enriched in PML-I vs. PML-IV. • Alternative splicing of eIF3K regulates association with PML bodies.

Trace Metal Requirements and Interactions in Symbiodinium kawagutii

Directory of Open Access Journals (Sweden)

Irene B. Rodriguez

2018-02-01

Full Text Available Photosynthetic organisms need trace metals for various biological processes and different groups of microalgae have distinctive obligate necessities due to their respective biochemical requirements and ecological niches. We have previously shown that the dinoflagellate Symbiodinium kawagutii requires high concentrations of bioavailable Fe to achieve optimum growth. Here, we further explored the trace metal requirements of S. kawagutii with intensive focus on the effect of individual metal and its interaction with other divalent metals. We found that low Zn availability significantly decreases growth rates and results in elevated intracellular Mn, Co, Ni, and Fe quotas in the dinoflagellate. The results highlight the complex interaction among trace metals in S. kawagutii and suggest either metal replacement strategy to counter low Zn availability or enhanced uptake of other metals by non-specific divalent metal transporters. In this work, we also examined the Fe requirement of S. kawagutii using continuous cultures. We validated that 500 pM of Fe′ was sufficient to support maximum cell density during steady state growth period either at 26 or 28°C. This study shows that growth of S. kawagutii was limited by metal availability in the following order, Fe > Zn > Mn > Cu > Ni > Co. The fundamental information obtained for the free-living Symbiodinium shall provide insights into how trace metal availability, either from ambient seawater or hosts, affects growth and proliferation of symbiotic dinoflagellates and the interaction between symbiont and their hosts.

Many-body Green’s function theory for electron-phonon interactions: Ground state properties of the Holstein dimer

International Nuclear Information System (INIS)

Säkkinen, Niko; Leeuwen, Robert van; Peng, Yang; Appel, Heiko

2015-01-01

We study ground-state properties of a two-site, two-electron Holstein model describing two molecules coupled indirectly via electron-phonon interaction by using both exact diagonalization and self-consistent diagrammatic many-body perturbation theory. The Hartree and self-consistent Born approximations used in the present work are studied at different levels of self-consistency. The governing equations are shown to exhibit multiple solutions when the electron-phonon interaction is sufficiently strong, whereas at smaller interactions, only a single solution is found. The additional solutions at larger electron-phonon couplings correspond to symmetry-broken states with inhomogeneous electron densities. A comparison to exact results indicates that this symmetry breaking is strongly correlated with the formation of a bipolaron state in which the two electrons prefer to reside on the same molecule. The results further show that the Hartree and partially self-consistent Born solutions obtained by enforcing symmetry do not compare well with exact energetics, while the fully self-consistent Born approximation improves the qualitative and quantitative agreement with exact results in the same symmetric case. This together with a presented natural occupation number analysis supports the conclusion that the fully self-consistent approximation describes partially the bipolaron crossover. These results contribute to better understanding how these approximations cope with the strong localizing effect of the electron-phonon interaction

Four-particle scattering with three-particle interactions

International Nuclear Information System (INIS)

Adhikari, S.K.

1979-01-01

The four-particle scattering formalism proposed independently by Alessandrini, by Mitra et al., by Rosenberg, and by Takahashi and Mishima is extended to include a possible three-particle interaction. The kernel of the new equations we get contain both two- and three-body connected parts and gets four-body connected after one iteration. On the other hand, the kernel of the original equations in the absence of three-particle interactions does not have a two-body connected part. We also write scattering equations for the transition operators connecting the two-body fragmentation channels. They are generalization of the Sloan equations in the presence of three-particle interactions. We indicate how to include approximately the effect of a weak three-particle interaction in a practical four-particle scattering calculation

Two-body loss rates for reactive collisions of cold atoms

Science.gov (United States)

Cop, C.; Walser, R.

2018-01-01

We present an effective two-channel model for reactive collisions of cold atoms. It augments elastic molecular channels with an irreversible, inelastic loss channel. Scattering is studied with the distorted-wave Born approximation and yields general expressions for angular momentum resolved cross sections as well as two-body loss rates. Explicit expressions are obtained for piecewise constant potentials. A pole expansion reveals simple universal shape functions for cross sections and two-body loss rates in agreement with the Wigner threshold laws. This is applied to collisions of metastable 20Ne and 21Ne atoms, which decay primarily through exothermic Penning or associative ionization processes. From a numerical solution of the multichannel Schrödinger equation using the best currently available molecular potentials, we have obtained synthetic scattering data. Using the two-body loss shape functions derived in this paper, we can match these scattering data very well.

On the two-body problem in quantum mechanics

International Nuclear Information System (INIS)

Micu, L.

2008-01-01

Following the representation of a two-body system in classical mechanics, we build up a quantum picture which is free of spurious effects and retains the intrinsic features of the internal bodies. In the coordinate space the system is represented by the real particles, individually bound to a center of forces which in a certain limit coincides with the center of mass and the wave function writes as product of the individual wave functions with correlated arguments. (author)

Institutional Solutions to the ``Two-Body Problem"

Science.gov (United States)

Knezek, P.

2005-05-01

The Committee on the Status of Women (CSWA), in conjunction with the Employment Committee (EC), will hold a special session that will focus on institutional approaches to solving the ``two-body problem". In step with the national employment trend, for the majority of astronomers with partners, those partners work outside the home. This is particularly true for female astronomers, who generally are married to professionals (and often to other astronomers). Academic and professional institutions that employ the majority of astronomers are now beginning to recognize the importance of addressing what has come to be known as the ``two-body" problem in order to attract and retain the best scientists. A few of those institutions are making pioneering efforts to create pro-active approaches to the issue of dual-career couples. The special session will feature two or three speakers involved with the administration at institutions with pro-active policies. This special session will be coupled with the normal afternoon CSWA session, which will focus on the other side of the issue - how dual-career couples have successfully approached the issue at institutions that do NOT have proactive policies.

Two Proximal Skin Electrodes — A Respiration Rate Body Sensor

Directory of Open Access Journals (Sweden)

Viktor Avbelj

2012-10-01

Full Text Available We propose a new body sensor for extracting the respiration rate based on the amplitude changes in the body surface potential differences between two proximal body electrodes. The sensor could be designed as a plaster-like reusable unit that can be easily fixed onto the surface of the body. It could be equipped either with a sufficiently large memory for storing the measured data or with a low-power radio system that can transmit the measured data to a gateway for further processing. We explore the influence of the sensor’s position on the quality of the extracted results using multi-channel ECG measurements and considering all the pairs of two neighboring electrodes as potential respiration-rate sensors. The analysis of the clinical measurements, which also include reference thermistor-based respiration signals, shows that the proposed approach is a viable option for monitoring the respiration frequency and for a rough classification of breathing types. The obtained results were evaluated on a wireless prototype of a respiration body sensor. We indicate the best positions for the respiration body sensor and prove that a single sensor for body surface potential difference on proximal skin electrodes can be used for combined measurements of respiratory and cardiac activities.

Importance of momentum dependence interaction on the isospin effects of two-body dissipation

International Nuclear Information System (INIS)

Yang Yanfang; Guo Wenjun; Zhao Qiang; Liu Jianye; Zuo Wei

2002-01-01

The role of momentum dependence equation of state on the nuclear stopping for the isospin dependence and the isospin independence of in-medium nucleon-nucleon cross section is studied by using the isospin dependence quantum molecular dynamics. The nuclear stopping depends strongly on the isospin dependence of in-medium nucleon-nucleon cross section and weakly on the isospin dependence of the mean field-symmetry potential from above the Fermi energy to about 150 MeV/u for the small impact parameters. A detail study indicates that the difference between the nuclear stopping for the isospin dependence and the isospin independence of in-medium nucleon-nucleon cross section depends sensitively on the momentum dependence interaction, namely, the difference between the nuclear stopping for the isospin dependence and the isospin independence of in-medium nucleon-nucleon cross section in the present of momentum dependence interaction is larger than that without the momentum dependence interaction (MDI) for the mass symmetry and mass asymmetry reaction systems, neutron-rich and neutron-poor reaction systems. Namely, MDI increases the sensitivity of the nuclear stopping on the isospin dependence nucleon-nucleon cross section. Therefore, the knowledge on the isospin dependence of in-medium nucleon-nucleon cross section can be extracted more accurately from nucleon stopping as a probe if the momentum dependence interaction is taken into account

An interactive VR system based on full-body tracking and gesture recognition

Science.gov (United States)

Zeng, Xia; Sang, Xinzhu; Chen, Duo; Wang, Peng; Guo, Nan; Yan, Binbin; Wang, Kuiru

2016-10-01

Most current virtual reality (VR) interactions are realized with the hand-held input device which leads to a low degree of presence. There is other solutions using sensors like Leap Motion to recognize the gestures of users in order to interact in a more natural way, but the navigation in these systems is still a problem, because they fail to map the actual walking to virtual walking only with a partial body of the user represented in the synthetic environment. Therefore, we propose a system in which users can walk around in the virtual environment as a humanoid model, selecting menu items and manipulating with the virtual objects using natural hand gestures. With a Kinect depth camera, the system tracks the joints of the user, mapping them to a full virtual body which follows the move of the tracked user. The movements of the feet can be detected to determine whether the user is in walking state, so that the walking of model in the virtual world can be activated and stopped by means of animation control in Unity engine. This method frees the hands of users comparing to traditional navigation way using hand-held device. We use the point cloud data getting from Kinect depth camera to recognize the gestures of users, such as swiping, pressing and manipulating virtual objects. Combining the full body tracking and gestures recognition using Kinect, we achieve our interactive VR system in Unity engine with a high degree of presence.

Interaction of ethanol and mercury body burden in the mouse

Energy Technology Data Exchange (ETDEWEB)

Dunn, J.D.

1978-01-01

The interaction of ethanol with mercury in the body resulting in increased exhalation of the metal was studied in the mouse. A persistent elimination of the metal in the breath was demonstrated after single, sublethal (<1 mgHg/Kg body weight) exposures to mercury vapor (Hg/sup 0/) or mercury II chloride (HgCl/sub 2/). The amount of mercury exhaled per unit time was enhanced by oral or parenteral administration of ethanol solutions. These modifications were investigated in dose-response studies in which the drug was administered in doses ranging from 0.2g to 5.5g/Kg to mice pretreated with mercury. The EC/sub 50/ for blood ethanol with respect to mercury exhalation was determined to be approximately 200 mg/dl corresponding to an output rate of approximately 0.1% of the simultaneous body burden in 30 min several days after mercury. A hypothesis that mercury expired by these animals was proportional to the body burden after mercury administration was addressed in experiments whereby mice given one of several doses of mercuric chloride (0.16 to 500 ..mu..g/Kg) were monitored for pulmonary mercury elimination for a fifteen day period. The high correlation obtained between the amount of mercury exhaled in a standard time period and the body burden by group indicated that breath sampling could be applied as an indicator of the mercury body burden which may not be limited to the mouse.

Mushroom body glycolysis is required for olfactory memory in Drosophila.

Science.gov (United States)

Wu, Chia-Lin; Chang, Ching-Ching; Wu, Jie-Kai; Chiang, Meng-Hsuan; Yang, Chu-Huai; Chiang, Hsueh-Cheng

2018-04-01

Glucose catabolism, also known as glycolysis, is important for energy generation and involves a sequence of enzymatic reactions that convert a glucose molecule into two pyruvate molecules. The glycolysis process generates adenosine triphosphate as a byproduct. In this study, we investigated whether glycolysis plays a role in maintaining neuronal functions in the Drosophila mushroom bodies (MBs), which are generally accepted to be an olfactory learning and memory center. Our data showed that individual knockdown of glycolytic enzymes in the MBs, including hexokinase (HexA), phosphofructokinase (Pfk), or pyruvate kinase (PyK), disrupts olfactory memory. Whole-mount brain immunostaining indicated that pyruvate kinase is strongly expressed in the MB αβ, α'β', and γ neuron subsets. We conclude that HexA, Pfk, and PyK are required in each MB neuron subset for olfactory memory formation. Our data therefore indicates that glucose catabolism in the MBs is important for olfactory memory formation in Drosophila. Copyright © 2018 Elsevier Inc. All rights reserved.

Measurements of Charmless Three-Body and Quasi-Two-Body B Decays

Energy Technology Data Exchange (ETDEWEB)

Barrera, Barbara

2000-08-28

The authors present preliminary results of a search for several exclusive charmless hadronic B decays from electron-positron annihilation data collected by the BaBar detector near the Upsilon(4S) resonance. These include three-body decay modes with final states h{+-}h{sup minus-plus}h{+-} and h{+-}h{sup minus-plus}pi{sup 0}, and quasi-two-body decay modes with final states X{sup 0}h and X{sup 0}K{sub S}{sup 0}, where h = pi or K and X{sup 0} = eta-prime or omega. They find beta(B{sup 0} --> rho{sup minus-plus}pi{sup {+-}}) = (49{+-}13{sub {minus}5}{sup +6}) x 10{sup {minus}6} and beta(B{sup +} --> eta-prime-K{sup +}) = (62{+-}18{+-}8) x 10{sup {minus}6} and present upper limits for right other decays.

Genome-Wide Interactions with Dairy Intake for Body Mass Index in Adults of European Descent

DEFF Research Database (Denmark)

Smith, Caren E; Follis, Jack L; Dashti, Hassan S

2018-01-01

SCOPE: Body weight responds variably to the intake of dairy foods. Genetic variation may contribute to inter-individual variability in associations between body weight and dairy consumption. METHODS AND RESULTS: A genome-wide interaction study to discover genetic variants that account for variati...

Two-body similarity and its violation in tokamak edge plasmas

International Nuclear Information System (INIS)

Catto, P.J.; Knoll, D.A.; Krasheninnikov, S.I.

1996-01-01

Scaling laws found under the assumption that two-body collisions dominate can be effectively used to benchmark complex multi-dimensional codes dedicated to investigating tokamak edge plasmas. The applicability of such scaling laws to the interpretation of experimental data, however, is found to be restricted to the relatively low plasma densities ( 19 m -3 ) at which multistep processes, which break the two-body collision approximation, are unimportant. copyright 1996 American Institute of Physics

Lunar ground penetrating radar: Minimizing potential data artifacts caused by signal interaction with a rover body

Science.gov (United States)

Angelopoulos, Michael; Redman, David; Pollard, Wayne H.; Haltigin, Timothy W.; Dietrich, Peter

2014-11-01

Ground-penetrating radar (GPR) is the leading geophysical candidate technology for future lunar missions aimed at mapping shallow stratigraphy (lunar materials, as well as its small size and lightweight components, make it a very attractive option from both a scientific and engineering perspective. However, the interaction between a GPR signal and the rover body is poorly understood and must be investigated prior to a space mission. In doing so, engineering and survey design strategies should be developed to enhance GPR performance in the context of the scientific question being asked. This paper explores the effects of a rover (simulated with a vertical metal plate) on GPR results for a range of heights above the surface and antenna configurations at two sites: (i) a standard GPR testing site with targets of known position, size, and material properties, and; (ii) a frozen lake for surface reflectivity experiments. Our results demonstrate that the GPR antenna configuration is a key variable dictating instrument design, with the XX polarization considered optimal for minimizing data artifact generation. These findings could thus be used to help guide design requirements for an eventual flight instrument.

Situated Meaning-Making of the Human Body: A Study of Elementary School Children's Reasons in Two Different Activities

Science.gov (United States)

Lundin, Mattias; Jakobson, Britt

2014-01-01

In this text we compare children's expressions in drawings to their statements during interviews, for the purpose of understanding how different situations afford children to make meaning. In specific we study how two different activities interact and afford children to make meaning differently about the human body. The analytic attention is…

Solvable quantum two-body problem: entanglement

International Nuclear Information System (INIS)

Glasser, M L; Nieto, L M

2005-01-01

A simple one-dimensional model is introduced describing a two particle 'atom' approaching a point at which the interaction between the particles is lost. The wavefunction is obtained analytically and analysed to display the entangled nature of the subsequent state. (letter to the editor)

Toward transferable interatomic van der Waals interactions without electrons: The role of multipole electrostatics and many-body dispersion

International Nuclear Information System (INIS)

Bereau, Tristan; Lilienfeld, O. Anatole von

2014-01-01

We estimate polarizabilities of atoms in molecules without electron density, using a Voronoi tesselation approach instead of conventional density partitioning schemes. The resulting atomic dispersion coefficients are calculated, as well as many-body dispersion effects on intermolecular potential energies. We also estimate contributions from multipole electrostatics and compare them to dispersion. We assess the performance of the resulting intermolecular interaction model from dispersion and electrostatics for more than 1300 neutral and charged, small organic molecular dimers. Applications to water clusters, the benzene crystal, the anti-cancer drug ellipticine—intercalated between two Watson-Crick DNA base pairs, as well as six macro-molecular host-guest complexes highlight the potential of this method and help to identify points of future improvement. The mean absolute error made by the combination of static electrostatics with many-body dispersion reduces at larger distances, while it plateaus for two-body dispersion, in conflict with the common assumption that the simple 1/R 6 correction will yield proper dissociative tails. Overall, the method achieves an accuracy well within conventional molecular force fields while exhibiting a simple parametrization protocol

Toward transferable interatomic van der Waals interactions without electrons: The role of multipole electrostatics and many-body dispersion

Energy Technology Data Exchange (ETDEWEB)

Bereau, Tristan, E-mail: bereau@mpip-mainz.mpg.de [Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany and Department of Chemistry, University of Basel, 4056 Basel (Switzerland); Lilienfeld, O. Anatole von [Department of Chemistry, Institute of Physical Chemistry, University of Basel, 4056 Basel, Switzerland and Argonne Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2014-07-21

We estimate polarizabilities of atoms in molecules without electron density, using a Voronoi tesselation approach instead of conventional density partitioning schemes. The resulting atomic dispersion coefficients are calculated, as well as many-body dispersion effects on intermolecular potential energies. We also estimate contributions from multipole electrostatics and compare them to dispersion. We assess the performance of the resulting intermolecular interaction model from dispersion and electrostatics for more than 1300 neutral and charged, small organic molecular dimers. Applications to water clusters, the benzene crystal, the anti-cancer drug ellipticine—intercalated between two Watson-Crick DNA base pairs, as well as six macro-molecular host-guest complexes highlight the potential of this method and help to identify points of future improvement. The mean absolute error made by the combination of static electrostatics with many-body dispersion reduces at larger distances, while it plateaus for two-body dispersion, in conflict with the common assumption that the simple 1/R{sup 6} correction will yield proper dissociative tails. Overall, the method achieves an accuracy well within conventional molecular force fields while exhibiting a simple parametrization protocol.

A two-particle exchange interaction model

International Nuclear Information System (INIS)

Lyubina, Julia; Mueller, Karl-Hartmut; Wolf, Manfred; Hannemann, Ullrich

2010-01-01

The magnetisation reversal of two interacting particles was investigated within a simple model describing exchange coupling of magnetically uniaxial single-domain particles. Depending on the interaction strength W, the reversal may be cooperative or non-cooperative. A non-collinear reversal mode is obtained even for two particles with parallel easy axes. The model yields different phenomena as observed in spring magnets such as recoil hysteresis in the second quadrant of the field-magnetisation-plane, caused by exchange bias, as well as the mentioned reversal-rotation mode. The Wohlfarth's remanence analysis performed on aggregations of such pairs of interacting particles shows that the deviation δM(H m ) usually being considered as a hallmark of magnetic interaction vanishes for all maximum applied fields H m not only at W=0, but also for sufficiently large values of W. Furthermore, this so-called δM-plot depends on whether the sample is ac-field or thermally demagnetised.

A two-particle exchange interaction model

Energy Technology Data Exchange (ETDEWEB)

Lyubina, Julia, E-mail: j.lyubina@ifw-dresden.d [IFW Dresden, Institute for Metallic Materials, P.O. Box 270016, D-01171 Dresden (Germany); Mueller, Karl-Hartmut; Wolf, Manfred; Hannemann, Ullrich [IFW Dresden, Institute for Metallic Materials, P.O. Box 270016, D-01171 Dresden (Germany)

2010-10-15

The magnetisation reversal of two interacting particles was investigated within a simple model describing exchange coupling of magnetically uniaxial single-domain particles. Depending on the interaction strength W, the reversal may be cooperative or non-cooperative. A non-collinear reversal mode is obtained even for two particles with parallel easy axes. The model yields different phenomena as observed in spring magnets such as recoil hysteresis in the second quadrant of the field-magnetisation-plane, caused by exchange bias, as well as the mentioned reversal-rotation mode. The Wohlfarth's remanence analysis performed on aggregations of such pairs of interacting particles shows that the deviation {delta}M(H{sub m}) usually being considered as a hallmark of magnetic interaction vanishes for all maximum applied fields H{sub m} not only at W=0, but also for sufficiently large values of W. Furthermore, this so-called {delta}M-plot depends on whether the sample is ac-field or thermally demagnetised.

77 FR 31086 - Requirements Pertaining to Third Party Conformity Assessment Bodies

Science.gov (United States)

2012-05-24

... 22030 (April 20, 2011). Third Party Testing for Certain Children's Products; Toys: Requirements for... Bodies to Assess Conformity With the Limits on Phthalates in Children's Toys and Child Care Articles, 76... initiatives, including program development for third party testing of children's products. The commenter...

Comparison of a two-body threshold (π,2π) reaction mechanism with the usual one-body mechanism in the deuteron

International Nuclear Information System (INIS)

Rockmore, R.

1984-01-01

A two-body threshold (π +- ,π +- π -+ ) reaction mechanism is suggested in direct analogy with pion absorption. The mechanism involves boson rescattering via Δ excitation. The relative importance of this mechanism and the ordinary one-body mechanism in nuclei is studied in the particular case of S-wave deuteron targets. The contribution of the two-body mechanism to the threshold reaction cross section is found to be less than 1% of the simple one-body estimate

Two-Level Designs to Estimate All Main Effects and Two-Factor Interactions

NARCIS (Netherlands)

Eendebak, P.T.; Schoen, E.D.

2017-01-01

We study the design of two-level experiments with N runs and n factors large enough to estimate the interaction model, which contains all the main effects and all the two-factor interactions. Yet, an effect hierarchy assumption suggests that main effect estimation should be given more prominence

Spectroscopy of collective excitations in interacting low-dimensional many-body systems using quench dynamics.

Science.gov (United States)

Gritsev, Vladimir; Demler, Eugene; Lukin, Mikhail; Polkovnikov, Anatoli

2007-11-16

We study the problem of rapid change of the interaction parameter (quench) in a many-body low-dimensional system. It is shown that, measuring the correlation functions after the quench, the information about a spectrum of collective excitations in a system can be obtained. This observation is supported by analysis of several integrable models and we argue that it is valid for nonintegrable models as well. Our conclusions are supplemented by performing exact numerical simulations on finite systems. We propose that measuring the power spectrum in a dynamically split 1D Bose-Einsten condensate into two coupled condensates can be used as an experimental test of our predictions.

Low-Thrust Orbital Transfers in the Two-Body Problem

Directory of Open Access Journals (Sweden)

A. A. Sukhanov

2012-01-01

Full Text Available Low-thrust transfers between given orbits within the two-body problem are considered; the thrust is assumed power limited. A simple method for obtaining the transfer trajectories based on the linearization of the motion near reference orbits is suggested. Required calculation accuracy can be reached by means of use of a proper number of the reference orbits. The method may be used in the case of a large number of the orbits around the attracting center; no averaging is necessary in this case. The suggested method also is applicable to the cases of partly given final orbit and if there are constraints on the thrust direction. The method gives an optimal solution to the linearized problem which is not optimal for the original nonlinear problem; the difference between the optimal solutions to the original and linearized problems is estimated using a numerical example. Also examples illustrating the method capacities are given.

Curvilinear immersed boundary method for simulating fluid structure interaction with complex 3D rigid bodies

Science.gov (United States)

Borazjani, Iman; Ge, Liang; Sotiropoulos, Fotis

2008-08-01

The sharp-interface CURVIB approach of Ge and Sotiropoulos [L. Ge, F. Sotiropoulos, A numerical method for solving the 3D unsteady incompressible Navier-Stokes equations in curvilinear domains with complex immersed boundaries, Journal of Computational Physics 225 (2007) 1782-1809] is extended to simulate fluid structure interaction (FSI) problems involving complex 3D rigid bodies undergoing large structural displacements. The FSI solver adopts the partitioned FSI solution approach and both loose and strong coupling strategies are implemented. The interfaces between immersed bodies and the fluid are discretized with a Lagrangian grid and tracked with an explicit front-tracking approach. An efficient ray-tracing algorithm is developed to quickly identify the relationship between the background grid and the moving bodies. Numerical experiments are carried out for two FSI problems: vortex induced vibration of elastically mounted cylinders and flow through a bileaflet mechanical heart valve at physiologic conditions. For both cases the computed results are in excellent agreement with benchmark simulations and experimental measurements. The numerical experiments suggest that both the properties of the structure (mass, geometry) and the local flow conditions can play an important role in determining the stability of the FSI algorithm. Under certain conditions the FSI algorithm is unconditionally unstable even when strong coupling FSI is employed. For such cases, however, combining the strong coupling iteration with under-relaxation in conjunction with the Aitken's acceleration technique is shown to effectively resolve the stability problems. A theoretical analysis is presented to explain the findings of the numerical experiments. It is shown that the ratio of the added mass to the mass of the structure as well as the sign of the local time rate of change of the force or moment imparted on the structure by the fluid determine the stability and convergence of the FSI

Human UBL5 protein interacts with coilin and meets the Cajal bodies

International Nuclear Information System (INIS)

Švéda, Martin; Častorálová, Markéta; Lipov, Jan; Ruml, Tomáš; Knejzlík, Zdeněk

2013-01-01

Highlights: •Localization of the UBL5 protein in Hela cells was determined by fluorescence microscopy and biochemical fractionation. •Colocalization of UBL5 with Cajal bodies was observed. •Interaction of UBL5 with coilin was proven by pull-down. -- Abstract: UBL5 protein, a structural homologue of ubiquitin, was shown to be involved in pre-mRNA splicing and transcription regulation in yeast and Caenorhabditis elegans, respectively. However, role of the UBL5 human orthologue is still elusive. In our study, we observed that endogenous human UBL5 that was localized in the nucleus, partially associates with Cajal bodies (CBs), nuclear domains where spliceosomal components are assembled. Simultaneous expression of exogenous UBL5 and coilin resulted in their nuclear colocalization in HeLa cells. The ability of UBL5 to interact with coilin was proved by GST pull-down assay using coilin that was either in vitro translated or extracted from HEK293T cells. Further, our results showed that the UBL5–coilin interaction was not influenced by coilin phosphorylation. These results suggest that UBL5 could be targeted to CBs via its interaction with coilin. Relation between human UBL5 protein and CBs is in the agreement with current observations about yeast orthologue Hub1 playing important role in alternative splicing

Human UBL5 protein interacts with coilin and meets the Cajal bodies

Energy Technology Data Exchange (ETDEWEB)

Švéda, Martin; Častorálová, Markéta; Lipov, Jan; Ruml, Tomáš; Knejzlík, Zdeněk, E-mail: knejzliz@vscht.cz

2013-06-28

Highlights: •Localization of the UBL5 protein in Hela cells was determined by fluorescence microscopy and biochemical fractionation. •Colocalization of UBL5 with Cajal bodies was observed. •Interaction of UBL5 with coilin was proven by pull-down. -- Abstract: UBL5 protein, a structural homologue of ubiquitin, was shown to be involved in pre-mRNA splicing and transcription regulation in yeast and Caenorhabditis elegans, respectively. However, role of the UBL5 human orthologue is still elusive. In our study, we observed that endogenous human UBL5 that was localized in the nucleus, partially associates with Cajal bodies (CBs), nuclear domains where spliceosomal components are assembled. Simultaneous expression of exogenous UBL5 and coilin resulted in their nuclear colocalization in HeLa cells. The ability of UBL5 to interact with coilin was proved by GST pull-down assay using coilin that was either in vitro translated or extracted from HEK293T cells. Further, our results showed that the UBL5–coilin interaction was not influenced by coilin phosphorylation. These results suggest that UBL5 could be targeted to CBs via its interaction with coilin. Relation between human UBL5 protein and CBs is in the agreement with current observations about yeast orthologue Hub1 playing important role in alternative splicing.

The two-brain approach: how can mutually interacting brains teach us something about social interaction?

Directory of Open Access Journals (Sweden)

Ivana eKonvalinka

2012-07-01

Full Text Available Measuring brain activity simultaneously from two people interacting is intuitively appealing if one is interested in putative neural markers of social interaction. However, given the complex nature of two-person interactions, it has proven difficult to carry out two-person brain imaging experiments in a methodologically feasible and conceptually relevant way. Only a small number of recent studies have put this into practice, using fMRI, EEG, or NIRS. Here, we review two main two-brain methodological approaches, each with two conceptual strategies. The first group has employed simultaneous fMRI recordings, studying a turn-based interactions on the order of seconds, or b pseudo-interactive scenarios, where only one person is scanned at a time, investigating the flow of information between brains. The second group of studies has recorded dual EEG/NIRS from two people interacting, in a face-to-face turn-based interactions, investigating functional connectivity between theory-of-mind regions of interacting partners, or in b continuous mutual interactions on millisecond timescales, to measure coupling between the activity in one person’s brain and the activity in the other’s brain. We discuss the questions these approaches have addressed, and consider scenarios when simultaneous two-brain recordings are needed. Furthermore, we suggest that a quantification of inter-personal neural effects via measures of emergence, and b multivariate decoding models that generalize source-specific features of interaction, may provide novel tools to study brains in interaction. This may allow for a better understanding of social cognition as both representation and participation.

Saturated fat intake modulates the association between an obesity genetic risk score and body mass index in two US populations.

Science.gov (United States)

Casas-Agustench, Patricia; Arnett, Donna K; Smith, Caren E; Lai, Chao-Qiang; Parnell, Laurence D; Borecki, Ingrid B; Frazier-Wood, Alexis C; Allison, Matthew; Chen, Yii-Der Ida; Taylor, Kent D; Rich, Stephen S; Rotter, Jerome I; Lee, Yu-Chi; Ordovás, José M

2014-12-01

Combining multiple genetic variants related to obesity into a genetic risk score (GRS) might improve identification of individuals at risk of developing obesity. Moreover, characterizing gene-diet interactions is a research challenge to establish dietary recommendations to individuals with higher predisposition to obesity. Our objective was to analyze the association between an obesity GRS and body mass index (BMI) in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) population, focusing on gene-diet interactions with total fat and saturated fatty acid (SFA) intake, and to replicate findings in the Multi-Ethnic Study of Atherosclerosis (MESA) population. Cross-sectional analyses included 783 white US participants from GOLDN and 2,035 from MESA. Dietary intakes were estimated with validated food frequency questionnaires. Height and weight were measured. A weighted GRS was calculated on the basis of 63 obesity-associated variants. Multiple linear regression models adjusted by potential confounders were used to examine gene-diet interactions between dietary intake (total fat and SFA) and the obesity GRS in determining BMI. Significant interactions were found between total fat intake and the obesity GRS using these variables as continuous for BMI (P for interaction=0.010, 0.046, and 0.002 in GOLDN, MESA, and meta-analysis, respectively). These association terms were stronger when assessing interactions between SFA intake and GRS for BMI (P for interaction=0.005, 0.018, and obesity GRS in modulating BMI in two US populations. Although determining the causal direction requires further investigation, these findings suggest that potential dietary recommendations to reduce BMI effectively in populations with high obesity GRS would be to reduce total fat intake mainly by limiting SFAs. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Circular relativistic motion of two identical bodies

International Nuclear Information System (INIS)

Shavokhina, N.S.

1983-01-01

Circular relativistic motion of two bodies as a solution of the earlier obtained equations with a deflecting argument where the self-deflection of the argument is an unknown function of time is considered. In case of circular motion the argument deflection is independent from time and it is the root of the transcendental equation obtained in the paper

Estimation Of Body Weight From Linear Body Measurements In Two ...

African Journals Online (AJOL)

The prediction of body weight from body girth, keel length and thigh length was studied using one hundred Ross and one hundred Anak Titan broilers. Data were collected on the birds from day-old to 9 weeks of age. Body measurement was regressed against body weight at 9 weeks of age using simple linear and ...

Probing many-body interactions in an optical lattice clock

Energy Technology Data Exchange (ETDEWEB)

Rey, A.M., E-mail: arey@jilau1.colorado.edu [JILA, NIST and University of Colorado, Department of Physics, Boulder, CO 80309 (United States); Gorshkov, A.V. [Joint Quantum Institute, NIST and University of Maryland, Department of Physics, College Park, MD 20742 (United States); Kraus, C.V. [Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck (Austria); Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria); Martin, M.J. [JILA, NIST and University of Colorado, Department of Physics, Boulder, CO 80309 (United States); Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA 91125 (United States); Bishof, M.; Swallows, M.D.; Zhang, X.; Benko, C.; Ye, J. [JILA, NIST and University of Colorado, Department of Physics, Boulder, CO 80309 (United States); Lemke, N.D.; Ludlow, A.D. [National Institute of Standards and Technology, Boulder, CO 80305 (United States)

2014-01-15

We present a unifying theoretical framework that describes recently observed many-body effects during the interrogation of an optical lattice clock operated with thousands of fermionic alkaline earth atoms. The framework is based on a many-body master equation that accounts for the interplay between elastic and inelastic p-wave and s-wave interactions, finite temperature effects and excitation inhomogeneity during the quantum dynamics of the interrogated atoms. Solutions of the master equation in different parameter regimes are presented and compared. It is shown that a general solution can be obtained by using the so called Truncated Wigner Approximation which is applied in our case in the context of an open quantum system. We use the developed framework to model the density shift and decay of the fringes observed during Ramsey spectroscopy in the JILA {sup 87}Sr and NIST {sup 171}Yb optical lattice clocks. The developed framework opens a suitable path for dealing with a variety of strongly-correlated and driven open-quantum spin systems. -- Highlights: •Derived a theoretical framework that describes many-body effects in a lattice clock. •Validated the analysis with recent experimental measurements. •Demonstrated the importance of beyond mean field corrections in the dynamics.

Interaction Deep Excavation Adjacent Structure Numerical Two and Three Dimensional Modeling

International Nuclear Information System (INIS)

Abdallah, M.; Chehade, F. H.; Chehade, W.; Fawaz, A.

2011-01-01

Urban development often requires the construction of deep excavations near to buildings or other structures. We have to study complex material structure interactions where we should take into consideration several particularities. In this paper, we perform a numerical modeling with the finite element method, using PLAXIS software, of the interaction deep excavation-diaphragm wall-soil-structure in the case of non linear soil behavior. We focus our study on a comparison of the results given respectively by two and three dimensional modelings. This allows us to give some recommendations concerning the validity of twodimensional study. We perform a parametric study according to the initial loading on the structure and the struts number. (author)

Genotype-covariate interaction effects and the heritability of adult body mass index

NARCIS (Netherlands)

Robinson, Matthew R.; English, Geoffrey; Moser, Gerhard; Lloyd-Jones, Luke R; Triplett, Marcus A; Zhu, Zhihong; Nolte, Ilja M; van Vliet-Ostaptchouk, Jana V; Snieder, Harold; Esko, Tonu; Milani, Lili; Mägi, Reedik; Metspalu, Andres; Magnusson, Patrik K. E.; Pedersen, Nancy L.; Ingelsson, Erik; Johannesson, Magnus; Yang, Jian; Cesarini, David; Visscher, Peter M.

Obesity is a worldwide epidemic, with major health and economic costs. Here we estimate heritability for body mass index (BMI) in 172,000 sibling pairs and 150,832 unrelated individuals and explore the contribution of genotype-covariate interaction effects at common SNP loci. We find evidence for

FaCE: a tool for Three Body Faddeev calculations with core excitation

OpenAIRE

Thompson, I. J.; Nunes, F. M.; Danilin, B. V.

2004-01-01

FaCE is a self contained programme, with namelist input, that solves the three body Faddeev equations. It enables the inclusion of excitation of one of the three bodies, whilst the other two remain inert. It is particularly useful for obtaining the binding energies and bound state structure compositions of light exotic nuclei treated as three-body systems, given the three effective two body interactions. A large variety of forms for these interactions may be defined, and supersymmetric transf...

Scattering Length Scaling Laws for Ultracold Three-Body Collisions

International Nuclear Information System (INIS)

D'Incao, J.P.; Esry, B.D.

2005-01-01

We present a simple and unifying picture that provides the energy and scattering length dependence for all inelastic three-body collision rates in the ultracold regime for three-body systems with short-range two-body interactions. Here, we present the scaling laws for vibrational relaxation, three-body recombination, and collision-induced dissociation for systems that support s-wave two-body collisions. These systems include three identical bosons, two identical bosons, and two identical fermions. Our approach reproduces all previous results, predicts several others, and gives the general form of the scaling laws in all cases

Interactions between internal forces, body stiffness, and fluid environment in a neuromechanical model of lamprey swimming.

Science.gov (United States)

Tytell, Eric D; Hsu, Chia-Yu; Williams, Thelma L; Cohen, Avis H; Fauci, Lisa J

2010-11-16

Animal movements result from a complex balance of many different forces. Muscles produce force to move the body; the body has inertial, elastic, and damping properties that may aid or oppose the muscle force; and the environment produces reaction forces back on the body. The actual motion is an emergent property of these interactions. To examine the roles of body stiffness, muscle activation, and fluid environment for swimming animals, a computational model of a lamprey was developed. The model uses an immersed boundary framework that fully couples the Navier-Stokes equations of fluid dynamics with an actuated, elastic body model. This is the first model at a Reynolds number appropriate for a swimming fish that captures the complete fluid-structure interaction, in which the body deforms according to both internal muscular forces and external fluid forces. Results indicate that identical muscle activation patterns can produce different kinematics depending on body stiffness, and the optimal value of stiffness for maximum acceleration is different from that for maximum steady swimming speed. Additionally, negative muscle work, observed in many fishes, emerges at higher tail beat frequencies without sensory input and may contribute to energy efficiency. Swimming fishes that can tune their body stiffness by appropriately timed muscle contractions may therefore be able to optimize the passive dynamics of their bodies to maximize peak acceleration or swimming speed.

Video-based quantification of body movement during social interaction indicates the severity of negative symptoms in patients with schizophrenia.

Science.gov (United States)

Kupper, Zeno; Ramseyer, Fabian; Hoffmann, Holger; Kalbermatten, Samuel; Tschacher, Wolfgang

2010-08-01

In schizophrenia, nonverbal behavior, including body movement, is of theoretical and clinical importance. Although reduced nonverbal expressiveness is a major component of the negative symptoms encountered in schizophrenia, few studies have objectively assessed body movement during social interaction. In the present study, 378 brief, videotaped role-play scenes involving 27 stabilized outpatients diagnosed with paranoid-type schizophrenia were analyzed using Motion Energy Analysis (MEA). This method enables the objective measuring of body movement in conjunction with ordinary video recordings. Correlations between movement parameters (percentage of time in movement, movement speed) and symptom ratings from independent PANSS interviews were calculated. Movement parameters proved to be highly reliable. In keeping with predictions, reduced movement and movement speed correlated with negative symptoms. Accordingly, in patients who exhibited noticeable movement for less than 20% of the observation time, prominent negative symptoms were highly probable. As a control measure, the percentage of movement exhibited by the patients during role-play scenes was compared to that of their normal interactants. Patients with negative symptoms differed from normal interactants by showing significantly reduced head and body movement. Two specific positive symptoms were possibly related to movement parameters: suspiciousness tended to correlate with reduced head movement, and the expression of unusual thought content tended to relate to increased movement. Overall, a close and theoretically meaningful association between the objective movement parameters and the symptom profiles was found. MEA appears to be an objective, reliable and valid method for quantifying nonverbal behavior, an aspect which may furnish new insights into the processes related to reduced expressiveness in schizophrenia. Copyright 2010 Elsevier B.V. All rights reserved.

A microscopic approach to Casimir and Casimir–Polder forces between metallic bodies

International Nuclear Information System (INIS)

Barcellona, Pablo; Passante, Roberto

2015-01-01

We consider the Casimir–Polder interaction energy between a metallic nanoparticle and a metallic plate, as well as the Casimir interaction energy between two macroscopic metal plates, in terms of the many-body dispersion interactions between their constituents. Expressions for two- and three-body dispersion interactions between the microscopic parts of a real metal are first obtained, both in the retarded and non-retarded limits. These expressions are then used to evaluate the overall two- and three-body contributions to the macroscopic Casimir–Polder and Casimir force, and to compare them with each other, for the two following geometries: metal nanoparticle/half-space and half-space/half-space, where all the materials are assumed perfect conductors. The above evaluation is obtained by summing up the contributions from the microscopic constituents of the bodies (metal nanoparticles). In the case of nanoparticle/half-space, our results fully agree with those that can be extracted from the corresponding macroscopic results, and explicitly show the non-applicability of the pairwise approximation for the geometry considered. In both cases, we find that, while the overall two-body contribution yields an attractive force, the overall three-body contribution is repulsive. Also, they turn out to be of the same order, consistently with the known non applicability of the pairwise approximation. The issue of the rapidity of convergence of the many-body expansion is also briefly discussed

Full Two-Body Problem Mass Parameter Observability Explored Through Doubly Synchronous Systems

Science.gov (United States)

Davis, Alex Benjamin; Scheeres, Daniel

2018-04-01

The full two-body problem (F2BP) is often used to model binary asteroid systems, representing the bodies as two finite mass distributions whose dynamics are influenced by their mutual gravity potential. The emergent behavior of the F2BP is highly coupled translational and rotational mutual motion of the mass distributions. For these systems the doubly synchronous equilibrium occurs when both bodies are tidally-locked and in a circular co-orbit. Stable oscillations about this equilibrium can be shown, for the nonplanar system, to be combinations of seven fundamental frequencies of the system and the mutual orbit rate. The fundamental frequencies arise as the linear periods of center manifolds identified about the equilibrium which are heavily influenced by each body’s mass parameters. We leverage these eight dynamical constraints to investigate the observability of binary asteroid mass parameters via dynamical observations. This is accomplished by proving the nonsingularity of the relationship between the frequencies and mass parameters for doubly synchronous systems. Thus we can invert the relationship to show that given observations of the frequencies, we can solve for the mass parameters of a target system. In so doing we are able to predict the estimation covariance of the mass parameters based on observation quality and define necessary observation accuracies for desired mass parameter certainties. We apply these tools to 617 Patroclus, a doubly synchronous Trojan binary and flyby target of the LUCY mission, as well as the Pluto and Charon system in order to predict mutual behaviors of these doubly synchronous systems and to provide observational requirements for these systems’ mass parameters

Traveller: An Interactive Cultural Training System Controlled by User-Defined Body Gestures

NARCIS (Netherlands)

Kistler, F.; André, E.; Mascarenhas, S.; Silva, A.; Paiva, A.; Degens, D.M.; Hofstede, G.J.; Krumhuber, E.; Kappas, A.; Aylett, R.

2013-01-01

In this paper, we describe a cultural training system based on an interactive storytelling approach and a culturally-adaptive agent architecture, for which a user-defined gesture set was created. 251 full body gestures by 22 users were analyzed to find intuitive gestures for the in-game actions in

1ST International Workshop on Managing Interactions in Smart Environments (MANSE 99)

Science.gov (United States)

1999-12-01

microphone arrays, and mice ; and also wireless interaction peripherals such as a wireless mouse or keyboard that can move about the room. • Scanners...constantly, for example 3D holographic displays, 3D " mice ", and body sensors. Such new modalities can be used in two ways: by taking advantage of their new...applications that monopolize the user’s attention or require excessive word knowledge; we allow people interacting with the Intelligent Room to readily

Review of Two-Photon Interactions

International Nuclear Information System (INIS)

Urner, David

2004-01-01

Presented are recent results of two-photon interactions. Topics include photon structure functions, inclusive hadron production, differential cross sections derived from tagged γγ fusion events and results in exclusive hadron production, particularly the observations of the η'c

Color variability and body size of larvae of two Epomis species (Coleoptera: Carabidae in Israel

Directory of Open Access Journals (Sweden)

Gil Wizen

2011-07-01

Full Text Available Species identification using the characteristics of developmental stages is challenging. However, for insect taxonomy the coloration of larval stages can be an informative feature. The use of live specimens is recommended for this because the color fades in preserved specimens. In this study we examine the possibility of using variation in coloration and color pattern of larvae in order to distinguish between two ground beetles species Epomis dejeani Dejean, 1831 and E. circumscriptus Duftschmid, 1812. We present an atlas and describe the coloration and body size of the three larval stages of the above species based on live specimens. The first instar larvae of the two Epomis species can be easily distinguished based on their color. From the second instar on, the variability in coloration and color patterns increases, creating an overlap in these attributes between larvae of the two species. Except for minor differences in color of the antennae and the base of the mandibles, larvae of the two species are indistinguishable at the second and third larval stages. To the best of our knowledge this is the first attempt to use variation in coloration and color pattern in live larvae in order to identify coleopterans. The color atlas of the larvae enables simple separation of the two Epomis species without requiring sophisticated magnifying devices, although it is less straightforward at the second and third larval stages. We found similar body lengths between the two species for all developmental stages, except for third instar larvae prior to pupation. In the two species the difference in larval body length before pupation positively correlated with that of the adult beetles. More than 70% of the adults' length can be explained by the length of the late third-instar larva; i.e. the large larvae develop into large adults. The larger specimens are the females.

A two-stage rule-constrained seedless region growing approach for mandibular body segmentation in MRI.

Science.gov (United States)

Ji, Dong Xu; Foong, Kelvin Weng Chiong; Ong, Sim Heng

2013-09-01

Extraction of the mandible from 3D volumetric images is frequently required for surgical planning and evaluation. Image segmentation from MRI is more complex than CT due to lower bony signal-to-noise. An automated method to extract the human mandible body shape from magnetic resonance (MR) images of the head was developed and tested. Anonymous MR images data sets of the head from 12 subjects were subjected to a two-stage rule-constrained region growing approach to derive the shape of the body of the human mandible. An initial thresholding technique was applied followed by a 3D seedless region growing algorithm to detect a large portion of the trabecular bone (TB) regions of the mandible. This stage is followed with a rule-constrained 2D segmentation of each MR axial slice to merge the remaining portions of the TB regions with lower intensity levels. The two-stage approach was replicated to detect the cortical bone (CB) regions of the mandibular body. The TB and CB regions detected from the preceding steps were merged and subjected to a series of morphological processes for completion of the mandibular body region definition. Comparisons of the accuracy of segmentation between the two-stage approach, conventional region growing method, 3D level set method, and manual segmentation were made with Jaccard index, Dice index, and mean surface distance (MSD). The mean accuracy of the proposed method is [Formula: see text] for Jaccard index, [Formula: see text] for Dice index, and [Formula: see text] mm for MSD. The mean accuracy of CRG is [Formula: see text] for Jaccard index, [Formula: see text] for Dice index, and [Formula: see text] mm for MSD. The mean accuracy of the 3D level set method is [Formula: see text] for Jaccard index, [Formula: see text] for Dice index, and [Formula: see text] mm for MSD. The proposed method shows improvement in accuracy over CRG and 3D level set. Accurate segmentation of the body of the human mandible from MR images is achieved with the

The nuclear N-body problem and the effective interaction in self-consistent mean-field methods

International Nuclear Information System (INIS)

Duguet, Thomas

2002-01-01

This work deals with two aspects of mean-field type methods extensively used in low-energy nuclear structure. The first study is at the mean-field level. The link between the wave-function describing an even-even nucleus and the odd-even neighbor is revisited. To get a coherent description as a function of the pairing intensity in the system, the utility of the formalization of this link through a two steps process is demonstrated. This two-steps process allows to identify the role played by different channels of the force when a nucleon is added in the system. In particular, perturbative formula evaluating the contribution of time-odd components of the functional to the nucleon separation energy are derived for zero and realistic pairing intensities. Self-consistent calculations validate the developed scheme as well as the derived perturbative formula. This first study ends up with an extended analysis of the odd-even mass staggering in nuclei. The new scheme allows to identify the contribution to this observable coming from different channels of the force. The necessity of a better understanding of time-odd terms in order to decide which odd-even mass formulae extracts the pairing gap the most properly is identified. These terms being nowadays more or less out of control, extended studies are needed to make precise the fit of a pairing force through the comparison of theoretical and experimental odd-even mass differences. The second study deals with beyond mean-field methods taking care of the correlations associated with large amplitude oscillations in nuclei. Their effects are usually incorporated through the GCM or the projected mean-field method. We derive a perturbation theory motivating such variational calculations from a diagrammatic point of view for the first time. Resuming two-body correlations in the energy expansion, we obtain an effective interaction removing the hard-core problem in the context of configuration mixing calculations. Proceeding to a

Two Pairs of Mushroom Body Efferent Neurons Are Required for Appetitive Long-Term Memory Retrieval in Drosophila

Directory of Open Access Journals (Sweden)

Pierre-Yves Plaçais

2013-11-01

Full Text Available One of the challenges facing memory research is to combine network- and cellular-level descriptions of memory encoding. In this context, Drosophila offers the opportunity to decipher, down to single-cell resolution, memory-relevant circuits in connection with the mushroom bodies (MBs, prominent structures for olfactory learning and memory. Although the MB-afferent circuits involved in appetitive learning were recently described, the circuits underlying appetitive memory retrieval remain unknown. We identified two pairs of cholinergic neurons efferent from the MB α vertical lobes, named MB-V3, that are necessary for the retrieval of appetitive long-term memory (LTM. Furthermore, LTM retrieval was correlated to an enhanced response to the rewarded odor in these neurons. Strikingly, though, silencing the MB-V3 neurons did not affect short-term memory (STM retrieval. This finding supports a scheme of parallel appetitive STM and LTM processing.

Interactions of bluff-body obstacles with turbulent airflows affecting evaporative fluxes from porous surfaces

Science.gov (United States)

Haghighi, Erfan; Or, Dani

2015-11-01

Bluff-body obstacles interacting with turbulent airflows are common in many natural and engineering applications (from desert pavement and shrubs over natural surfaces to cylindrical elements in compact heat exchangers). Even with obstacles of simple geometry, their interactions within turbulent airflows result in a complex and unsteady flow field that affects surface drag partitioning and transport of scalars from adjacent evaporating surfaces. Observations of spatio-temporal thermal patterns on evaporating porous surfaces adjacent to bluff-body obstacles depict well-defined and persistent zonation of evaporation rates that were used to construct a simple mechanistic model for surface-turbulence interactions. Results from evaporative drying of sand surfaces with isolated cylindrical elements (bluff bodies) subjected to constant turbulent airflows were in good agreement with model predictions for localized exchange rates. Experimental and theoretical results show persistent enhancement of evaporative fluxes from bluff-rough surfaces relative to smooth flat surfaces under similar conditions. The enhancement is attributed to formation of vortices that induce a thinner boundary layer over part of the interacting surface footprint. For a practical range of air velocities (0.5-4.0 m/s), low-aspect ratio cylindrical bluff elements placed on evaporating sand surfaces enhanced evaporative mass losses (relative to a flat surface) by up to 300% for high density of elements and high wind velocity, similar to observations reported in the literature. Concepts from drag partitioning were used to generalize the model and upscale predictions to evaporation from surfaces with multiple obstacles for potential applications to natural bluff-rough surfaces.

Three-body calculation of Be double-hypernuclei

Indian Academy of Sciences (India)

Energy levels and bond energy of the double- hypernucleus are calculated by considering two- and three-cluster interactions. Interactions between constituent particles are contact interactions for reproducing the low binding energy of nuclei. The effective action is constructed to involve three-body forces. In this paper ...

Comparison of two software versions for assessment of body-composition analysis by DXA

DEFF Research Database (Denmark)

Vozarova, B; Wang, J; Weyer, C

2001-01-01

To compare two software versions provided by Lunar CO: for assessment of body composition analysis by DXA.......To compare two software versions provided by Lunar CO: for assessment of body composition analysis by DXA....

Interactive urban design using integrated planning requirements control

NARCIS (Netherlands)

Vries, de B.; Tabak, V.; Achten, H.H.

2005-01-01

Urban planning and urban design are separated disciplines. As a consequence, there is hardly any feedback from the urban design process to the urban planning process. To improve interaction between these two, an interactive urban design (IUD) tool has been developed. The tool is implemented in a

The Validity of Two Education Requirement Measures

Science.gov (United States)

van der Meer, Peter H.

2006-01-01

In this paper we investigate the validity of two education requirement measures. This is important because a key part of the ongoing discussion concerning overeducation is about measurement. Thanks to the Dutch Institute for Labour Studies, we have been given a unique opportunity to compare two education requirement measures: first, Huijgen's…

Proposal for Requirement Validation Criteria and Method Based on Actor Interaction

Science.gov (United States)

Hattori, Noboru; Yamamoto, Shuichiro; Ajisaka, Tsuneo; Kitani, Tsuyoshi

We propose requirement validation criteria and a method based on the interaction between actors in an information system. We focus on the cyclical transitions of one actor's situation against another and clarify observable stimuli and responses based on these transitions. Both actors' situations can be listed in a state transition table, which describes the observable stimuli or responses they send or receive. Examination of the interaction between both actors in the state transition tables enables us to detect missing or defective observable stimuli or responses. Typically, this method can be applied to the examination of the interaction between a resource managed by the information system and its user. As a case study, we analyzed 332 requirement defect reports of an actual system development project in Japan. We found that there were a certain amount of defects regarding missing or defective stimuli and responses, which can be detected using our proposed method if this method is used in the requirement definition phase. This means that we can reach a more complete requirement definition with our proposed method.

The Quantum N-Body Problem and the Auxiliary Field Method

International Nuclear Information System (INIS)

Semay, C.; Buisseret, F.; Silvestre-Brac, B.

2011-01-01

Approximate analytical energy formulas for N-body semirelativistic Hamiltonians with one- and two-body interactions are obtained within the framework of the auxiliary field method. We first review the method in the case of nonrelativistic two-body problems. A general procedure is then given for N-body systems and applied to the case of baryons in the large-N c limit. (author)

Quantum-mechanical few-body scattering equations with half-on-shell energy-independent subsystem input

International Nuclear Information System (INIS)

Zeiger, E.M.

1978-01-01

New equations are presented for three- and four-body scattering, within the context of nonrelativistic quantum mechanics and a Hamiltonian scattering theory. For the three-body case Faddeev-type equations are presented which, although obtained from the rigorous Faddeev theory, only require two-body bound state wave functions and half-off-shell transition amplitudes as input. In addition, their effective potentials are independent of the three-body energy, and can easily be made real after an angular momentum decomposition. The equations are formulated in terms of physical transition amplitudes for three-body processes, except that in the breakup case the partial-wave amplitudes differ from the corresponding full amplitudes by a Watson final-state-interaction factor. Also presented are new equations for four-body scattering, obtained by generalizing our three-body formalism to the four-body case. These equations, although equivalent to those of Faddeev--Yakubovskii, are expressed in terms of singularity-free transition amplitudes, and their energy-independent effective potentials require only half-on-shell subsystem transition amplitudes (and bound state wave functions) as input. However, due to the detailed index structure of the Faddeev--Yakubovskii formalsim, the result of the generalization is considerably more complicated than in the three-body case

A Case of a Contraband Body Packer Requiring High-Dose Naloxone

Directory of Open Access Journals (Sweden)

Khusro Shamim

2017-09-01

Full Text Available Background:Body packers occasionally refer to the Emergency Department (ED, after leakage of package contents within intestinal lumen, resulting in life-threatening toxicities, depending upon the nature of the chemical product. Case Presentation: We present a case report of a patient presented with sudden onset of drowsiness while he was on board a flight. He was brought in by the airport security staff. On arrival to the ED, his Glasgow Coma Scale (GCS was 3/15 and pupils were pinpoint bilaterally. He was empirically treated with Naloxone on clinical suspicion of narcotic overdose. He required a cumulative dose of 12 mg of Naloxone for reversal of respiratory depression and coma. On subsequent investigation in the ED, he was identified to be a body packer. Discussion: This case represents a rare clinical example of narcotic overdose which resulted in a life-threatening opioid toxicity due to leakage of the package contents into his bowels. In this case, a dosage greater than 10 mg of the maximum recommended dose of Naloxone is required for reversal of toxicity. Conclusion:It is imperative to have a high level of suspicion for managing possible opioid intoxication as immediate treatment can be diagnostic and lifesaving. Our case required more than the recommended dosage of Naloxone, highlighting the possible suggestion of further studies to look into the maximum threshold of this reversal agent.

Interactive flow field around two Savonius turbines

Energy Technology Data Exchange (ETDEWEB)

Shigetomi, Akinari; Murai, Yuichi; Tasaka, Yuji; Takeda, Yasushi [Laboratory for Flow Control, Division of Energy and Environmental System, Faculty of Engineering, Hokkaido University, N13W8, Sapporo 060-8628 (Japan)

2011-02-15

The use of a Savonius type of vertical axis wind turbine is expanding in urban environments as a result of its ability to withstand turbulence as well as its relatively quiet operation. In the past, single turbine performance has been investigated primarily for determining the optimum blade configuration. In contrast, combining multiple Savonius turbines in the horizontal plane produces extra power in particular configurations. This results from the interaction between the two flow fields around individual turbines. To understand quantitatively the interaction mechanism, we measured the flow field around two Savonius turbines in close configurations using particle image velocimetry. The phase-averaged flow fields with respect to the rotation angle of the turbines revealed two types of power-improvement interactions. One comes from the Magnus effect that bends the main stream behind the turbine to provide additional rotation of the downstream turbine. The other is obtained from the periodic coupling of local flow between the two turbines, which is associated with vortex shedding and cyclic pressure fluctuations. Use of this knowledge will assist the design of packaged installations of multiple Savonius turbines. (author)

Classifying a Person's Degree of Accessibility From Natural Body Language During Social Human-Robot Interactions.

Science.gov (United States)

McColl, Derek; Jiang, Chuan; Nejat, Goldie

2017-02-01

For social robots to be successfully integrated and accepted within society, they need to be able to interpret human social cues that are displayed through natural modes of communication. In particular, a key challenge in the design of social robots is developing the robot's ability to recognize a person's affective states (emotions, moods, and attitudes) in order to respond appropriately during social human-robot interactions (HRIs). In this paper, we present and discuss social HRI experiments we have conducted to investigate the development of an accessibility-aware social robot able to autonomously determine a person's degree of accessibility (rapport, openness) toward the robot based on the person's natural static body language. In particular, we present two one-on-one HRI experiments to: 1) determine the performance of our automated system in being able to recognize and classify a person's accessibility levels and 2) investigate how people interact with an accessibility-aware robot which determines its own behaviors based on a person's speech and accessibility levels.

Yeast Interacting Proteins Database: YDR176W, YDL239C [Yeast Interacting Proteins Database

Lifescience Database Archive (English)

Full Text Available a Don1p-containing structure at the leading edge of the prospore membrane via interaction with spindle pole...ining structure at the leading edge of the prospore membrane via interaction with spindle pole body componen...DY3 Prey description Protein required for spore wall formation, thought to mediate assembly of a Don1p-conta

Translationally invariant multipartite Bell inequalities involving only two-body correlators

International Nuclear Information System (INIS)

Tura, J; B Sainz, A; Acín, A; Lewenstein, M; Augusiak, R; Vértesi, T

2014-01-01

Bell inequalities are natural tools that allow one to certify the presence of nonlocality in quantum systems. The known constructions of multipartite Bell inequalities contain, however, correlation functions involving all observers, making their experimental implementation difficult. The main purpose of this work is to explore the possibility of witnessing nonlocality in multipartite quantum states from the easiest-to-measure quantities, that is, the two-body correlations. In particular, we determine all three- and four-partite Bell inequalities constructed from one- and two-body expectation values that obey translational symmetry, and show that they reveal nonlocality in multipartite states. Also, by providing a particular example of a five-partite Bell inequality, we show that nonlocality can be detected from two-body correlators involving only nearest neighbours. Finally, we demonstrate that any translationally invariant Bell inequality can be maximally violated by a translationally invariant state and the same set of observables at all sites. We provide a numerical algorithm allowing one to seek for maximal violation of a translationally invariant Bell inequality. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘50 years of Bell’s theorem’. (paper)

Terminology for the body in social interaction, as appearing in papers published in the journal 'Research on Language and Social Interaction', 1987-2013

DEFF Research Database (Denmark)

Nevile, Maurice Richard

2016-01-01

This is a list of terms referring generally to the body in descriptions and analyses of social interaction, as used by authors in papers published in ROLSI. The list includes over 200 items, grouped according to common phrasing and within alphabetical order. The list was compiled in preparation...... for the review paper: Nevile, M. (2015) The embodied turn in research on language and social interaction. Research on Language and Social Interaction,48(2): 121-151....

Universal Two-Body Spectra of Ultracold Harmonically Trapped Atoms in Two and Three Dimensions

DEFF Research Database (Denmark)

Zinner, Nikolaj Thomas

2012-01-01

of the short-range interaction. The results in three dimensions are examplified for narrow s-wave Feshbach resonances and we show how effective range corrections can modify the rearrangement of the level structure. However, this requires extremely narrow resonances or very tight traps that are not currently...

Study on the characteristics of interaction flowfields induced by supersonic jet on a revolution body

Directory of Open Access Journals (Sweden)

S.J. Luo

2017-11-01

Full Text Available The paper focuses on the triple jets interaction with a hypersonic external flow on a revolution body. The experimental model is a ogive-cylinder body with three supersonic nozzles, which are aligned along the flow direction. The freestream Mach numbers are 5 and 6. The spatial and surface flow characteristics are illustrated by the schlieren photographs and the typical pressure distribution. The results show that there are multi-wave system, separation, reattachment, multi-peak pressure, high-pressure and low-pressure zone boundaries obvious distinction in tri-jets interference flowfield. The present paper also analyzes how do the pressure ratio, the angle of attack, and Mach number effect on tri-jets interaction characteristics.

Application of equivalent electrodes method to analysis of interaction between ELF-LF electric fields and human body

International Nuclear Information System (INIS)

Ceselkoska, Vesna C.; Velickovic, Dragutin M.

2002-01-01

This paper presents the use of equivalent electrodes method, numerical method, based on surface-charge equation to quantify the interaction of low frequencies electric fields with various models of human body. The evaluation of the electric field intensity on the body surface is performed for a realistic model of the human body. Several examples for different postures of the model are given. (Author)

Updated analysis of some two-body charmless B decays

International Nuclear Information System (INIS)

Chiang Chengwei; Rosner, Jonathan L.

2002-01-01

New data from the BaBar, Belle, and CLEO Collaborations on B decays to two-body charmless final states are analyzed, with the following consequences. (1) The penguin amplitude which dominates the decay B + →π + K *0 has a magnitude similar to that dominating B + →π + K 0 . (2) The decay B + →π + η, a good candidate for observing direct CP violation, should be detectable at present levels of sensitivity. (3) The decays B + →η ' K + and B + →ηK* + are sufficiently similar in rate to the corresponding decays B 0 →η ' K 0 and B 0 →ηK* 0 , respectively, that one cannot yet infer the need for 'tree' amplitudes t ' contributing to the B + but not the B 0 decays. Statistical requirements for observing this and other examples of tree-penguin interference are given. (4) Whereas the B + →η ' K + and B 0 →η ' K 0 rates cannot be accounted for by the penguin amplitude p ' alone but require an additional flavor-singlet penguin contribution s ' , no such flavor-singlet penguin contribution is yet called for in the decays B + →ηK* + or B 0 →ηK *0 . Predictions for the rates for B + →η ' K* + and B 0 →η ' K* 0 are given which would allow one to gauge the importance of these flavor-singlet penguin amplitudes

Precise numerical results for limit cycles in the quantum three-body problem

International Nuclear Information System (INIS)

Mohr, R.F.; Furnstahl, R.J.; Hammer, H.-W.; Perry, R.J.; Wilson, K.G.

2006-01-01

The study of the three-body problem with short-range attractive two-body forces has a rich history going back to the 1930s. Recent applications of effective field theory methods to atomic and nuclear physics have produced a much improved understanding of this problem, and we elucidate some of the issues using renormalization group ideas applied to precise nonperturbative calculations. These calculations provide 11-12 digits of precision for the binding energies in the infinite cutoff limit. The method starts with this limit as an approximation to an effective theory and allows cutoff dependence to be systematically computed as an expansion in powers of inverse cutoffs and logarithms of the cutoff. Renormalization of three-body bound states requires a short range three-body interaction, with a coupling that is governed by a precisely mapped limit cycle of the renormalization group. Additional three-body irrelevant interactions must be determined to control subleading dependence on the cutoff and this control is essential for an effective field theory since the continuum limit is not likely to match physical systems (e.g., few-nucleon bound and scattering states at low energy). Leading order calculations precise to 11-12 digits allow clear identification of subleading corrections, but these corrections have not been computed

Does seeing ice really feel cold? Visual-thermal interaction under an illusory body-ownership.

Directory of Open Access Journals (Sweden)

Shoko Kanaya

Full Text Available Although visual information seems to affect thermal perception (e.g. red color is associated with heat, previous studies have failed to demonstrate the interaction between visual and thermal senses. However, it has been reported that humans feel an illusory thermal sensation in conjunction with an apparently-thermal visual stimulus placed on a prosthetic hand in the rubber hand illusion (RHI wherein an individual feels that a prosthetic (rubber hand belongs to him/her. This study tests the possibility that the ownership of the body surface on which a visual stimulus is placed enhances the likelihood of a visual-thermal interaction. We orthogonally manipulated three variables: induced hand-ownership, visually-presented thermal information, and tactically-presented physical thermal information. Results indicated that the sight of an apparently-thermal object on a rubber hand that is illusorily perceived as one's own hand affects thermal judgments about the object physically touching this hand. This effect was not observed without the RHI. The importance of ownership of a body part that is touched by the visual object on the visual-thermal interaction is discussed.

B8B8 interaction in the SU6 quark model and its applications to few-body systems

International Nuclear Information System (INIS)

Fujiwara, Y.; Miyagawa, K.; Kohno, M.; Suzuki, Y.; Nakamoto, C.

2004-01-01

The recent QCD-inspired spin-flavor SU 6 quark model for the baryon-baryon interaction, proposed by the Kyoto-Niigata group, is a unified model for the complete baryon octet (B 8 =N, Λ, Σ and Ξ), which has achieved very accurate description of the NN and YN interactions. These quark-model interactions are now applied to realistic calculations of few-body systems in a new three-cluster Faddeev formalism which uses the 2-cluster resonating-group method kernel explicitly. We review the essential features of the most recent models, fss2 and FSS, and their predictions to few-body systems in confrontation with the available experimental data. As the few-body systems, we discuss the three-nucleon bound states, 2αΛ system for Λ 9 Be, and 2Λα system for ΛΛ 6 He. (author)

Measurement of the magnetic interaction between two bound electrons of two separate ions.

Science.gov (United States)

Kotler, Shlomi; Akerman, Nitzan; Navon, Nir; Glickman, Yinnon; Ozeri, Roee

2014-06-19

Electrons have an intrinsic, indivisible, magnetic dipole aligned with their internal angular momentum (spin). The magnetic interaction between two electronic spins can therefore impose a change in their orientation. Similar dipolar magnetic interactions exist between other spin systems and have been studied experimentally. Examples include the interaction between an electron and its nucleus and the interaction between several multi-electron spin complexes. The challenge in observing such interactions for two electrons is twofold. First, at the atomic scale, where the coupling is relatively large, it is often dominated by the much larger Coulomb exchange counterpart. Second, on scales that are substantially larger than the atomic, the magnetic coupling is very weak and can be well below the ambient magnetic noise. Here we report the measurement of the magnetic interaction between the two ground-state spin-1/2 valence electrons of two (88)Sr(+) ions, co-trapped in an electric Paul trap. We varied the ion separation, d, between 2.18 and 2.76 micrometres and measured the electrons' weak, millihertz-scale, magnetic interaction as a function of distance, in the presence of magnetic noise that was six orders of magnitude larger than the magnetic fields the electrons apply on each other. The cooperative spin dynamics was kept coherent for 15 seconds, during which spin entanglement was generated, as verified by a negative measured value of -0.16 for the swap entanglement witness. The sensitivity necessary for this measurement was provided by restricting the spin evolution to a decoherence-free subspace that is immune to collective magnetic field noise. Our measurements show a d(-3.0(4)) distance dependence for the coupling, consistent with the inverse-cube law.

Singularities in four-body final-state amplitudes

International Nuclear Information System (INIS)

Adhikari, S.K.

1978-01-01

Like three-body amplitudes, four-body amplitudes have subenergy threshold singularities over and above total-energy singularities. In the four-body problem we encounter a new type of subenergy singularity besides the usual two- and three-body subenergy threshold singularities. This singularity will be referred to as ''independent-pair threshold singularity'' and involves pair-subenergy threshold singularities in each of the two independent pair subenergies in four-body final states. We also study the particularly interesting case of resonant two- and three-body interactions in the four-body isobar model and the rapid (singular) dependence of the isobar amplitudes they generate in the four-body phase space. All these singularities are analyzed in the multiple-scattering formalism and it is shown that they arise from the ''next-to-last'' rescattering and hence may be represented correctly by an approximate amplitude which has that rescattering

Scalar meson field and many-body forces. Chapter 23

International Nuclear Information System (INIS)

Nyman, E.M.

1979-01-01

In applications of field theory to the theory of the nuclear forces, one has frequently assumed that there is a scalar meson. It will then be responsible for most of the medium-range attraction between the nucleons. According to current ideas, however, it is possible to account for the medium-range attraction without an elementary sigma meson. This approach requires a careful treatment of the exchange of interacting pairs of π mesons, such as to include those ππ interactions which are responsible for the formation and decay of the sigma meson. Recently, the scalar field in the nuclear many-body problem has begun to receive more attention. There are two reasons for this change of philosophy. One reason is the discovery of neutron stars. In neutron stars, the nucleon number density can be much higher than in nuclei. One therefore wants to derive the equation of state from a relativistic many-body theory. This forces one to deal explicitly with a set of mesons, such that in the non-relativistic limit one recovers the one-boson-exchange potential. (Auth.)

Three-body models of the 6ΛΛHe and 9ΛBe hypernuclei with non-local interactions

International Nuclear Information System (INIS)

Theeten, M.; Baye, D.; Descouvemont, P.

2005-01-01

A three-body model involving non-local interactions is developed in configuration space. It is based on a hyperspherical-harmonics expansion and the Lagrange-mesh method. The 6 ΛΛ He and 9 Λ Be hypernuclei are studied as three-body αΛΛ and ααΛ systems. Recently proposed quark-model based ΛN and ΛΛ interactions are used. A non-local Λα interaction is obtained by folding the ΛN interaction with a Gaussian α density. Various phenomenological αα interactions are employed. The results agree within 1 keV with recent Faddeev calculations in momentum space. Energies and radii of 6 ΛΛ He and 9 Λ Be are compared with a purely local model. The B(E2) between the 9 Λ Be bound states is also calculated. The role of non-locality is discussed

The importance of being equivalent: Newton's two models of one-body motion

Science.gov (United States)

Pourciau, Bruce

2004-05-01

As an undergraduate at Cambridge, Newton entered into his "Waste Book" an assumption that we have named the Equivalence Assumption (The Younger): "If a body move progressively in some crooked line [about a center of motion] ..., [then this] crooked line may bee conceived to consist of an infinite number of streight lines. Or else in any point of the croked line the motion may bee conceived to be on in the tangent". In this assumption, Newton somewhat imprecisely describes two mathematical models, a "polygonal limit model" and a "tangent deflected model", for "one-body motion", that is, for the motion of a "body in orbit about a fixed center", and then claims that these two models are equivalent. In the first part of this paper, we study the Principia to determine how the elder Newton would more carefully describe the polygonal limit and tangent deflected models. From these more careful descriptions, we then create Equivalence Assumption (The Elder), a precise interpretation of Equivalence Assumption (The Younger) as it might have been restated by Newton, after say 1687. We then review certain portions of the Waste Book and the Principia to make the case that, although Newton never restates nor even alludes to the Equivalence Assumption after his youthful Waste Book entry, still the polygonal limit and tangent deflected models, as well as an unspoken belief in their equivalence, infuse Newton's work on orbital motion. In particular, we show that the persuasiveness of the argument for the Area Property in Proposition 1 of the Principia depends crucially on the validity of Equivalence Assumption (The Elder). After this case is made, we present the mathematical analysis required to establish the validity of the Equivalence Assumption (The Elder). Finally, to illustrate the fundamental nature of the resulting theorem, the Equivalence Theorem as we call it, we present three significant applications: we use the Equivalence Theorem first to clarify and resolve questions

Pair Interaction of Dislocations in Two-Dimensional Crystals

Science.gov (United States)

Eisenmann, C.; Gasser, U.; Keim, P.; Maret, G.; von Grünberg, H. H.

2005-10-01

The pair interaction between crystal dislocations is systematically explored by analyzing particle trajectories of two-dimensional colloidal crystals measured by video microscopy. The resulting pair energies are compared to Monte Carlo data and to predictions derived from the standard Hamiltonian of the elastic theory of dislocations. Good agreement is found with respect to the distance and temperature dependence of the interaction potential, but not regarding the angle dependence where discrete lattice effects become important. Our results on the whole confirm that the dislocation Hamiltonian allows a quantitative understanding of the formation and interaction energies of dislocations in two-dimensional crystals.

Interactions between two magnetohydrodynamic Kelvin-Helmholtz instabilities

International Nuclear Information System (INIS)

Lai, S. H.; Ip, W.-H.

2011-01-01

Kelvin-Helmholtz instability (KHI) driven by velocity shear is a generator of waves found away from the vicinity of the velocity-shear layers since the fast-mode waves radiated from the surface perturbation can propagate away from the transition layer. Thus the nonlinear evolution associated with KHI is not confined near the velocity-shear layer. To understand the physical processes in multiple velocity-shear layers, the interactions between two KHIs at a pair of tangential discontinuities are studied by two-dimensional magnetohydrodynamic simulations. It is shown that the interactions between two neighboring velocity-shear layers are dominated by the propagation of the fast-mode waves radiated from KHIs in a nonuniform medium. That is, the fast-mode Mach number of the surface waves M Fy , a key factor of the nonlinear evolution of KHI, will vary with the nonuniform background plasma velocity due to the existence of two neighboring velocity-shear layers. As long as the M Fy observed in the plasma rest frame across the neighboring velocity-shear layer is larger than one, newly formed fast-mode Mach-cone-like (MCL) plane waves generated by the fast-mode waves can be found in this region. As results of the interactions of two KHIs, reflection and distortion of the MCL plane waves generate the turbulence and increase the plasma temperature, which provide possible mechanisms of heating and accelerating local plasma between two neighboring velocity-shear layers.

Calculation of the hyperfine interaction using an effective-operator form of many-body theory

International Nuclear Information System (INIS)

Garpman, S.; Lindgren, I.; Lindgren, J.; Morrison, J.

1975-01-01

The effective-operator form of many-body theory is reviewed and applied to the calculation of the hyperfine structure. Numerical results are given for the 2p, 3p, and 4p excited states of Li and the 3p state of Na. This is the first complete calculation of the hyperfine structure using an effective-operator form of perturbation theory. As in the Brueckner-Goldstone form of many-body theory, the various terms in the perturbation expansion are represented by Feynman diagrams which correspond to basic physical processes. The angular part of the perturbation diagrams are evaluated by taking advantage of the formal analogy between the Feynman diagrams and the angular-momentum diagrams, introduced by Jucys et al. The radial part of the diagrams is calculated by solving one- and two-particle equations for the particular linear combination of excited states that contribute to the Feynman diagrams. In this way all second- and third-order effects are accurately evaluated without explicitly constructing the excited orbitals. For the 2p state of Li our results are in agreement with the calculations of Nesbet and of Hameed and Foley. However, our quadrupole calculation disagrees with the work of Das and co-workers. The many-body results for Li and Na are compared with semiempirical methods for evaluating the quadrupole moment from the hyperfine interaction, and a new quadrupole moment of 23 Na is given

Designing interactive ambient multimedia applications : requirements and implementation challenges

NARCIS (Netherlands)

Obrenovic, Z.; Nack, F.-M.; Hardman, H.L.

2006-01-01

Ambient intelligence opens new possibilities for interactive multimedia, leading towards applications where the selection, generation and playback of multimedia content can be directed and influenced by multiple users in an ambient sensor network. In this paper, we derive the basic requirements for

Relativistic few body calculations

International Nuclear Information System (INIS)

Gross, F.

1988-01-01

A modern treatment of the nuclear few-body problem must take into account both the quark structure of baryons and mesons, which should be important at short range, and the relativistic exchange of mesons, which describes the long range, peripheral interactions. A way to model both of these aspects is described. The long range, peripheral interactions are calculated using the spectator model, a general approach in which the spectators to nucleon interactions are put on their mass-shell. Recent numerical results for a relativistic OBE model of the NN interaction, obtained by solving a relativistic equation with one-particle on mass-shell, will be presented and discussed. Two meson exchange models, one with only four mesons (π,σ,/rho/,ω) but with a 25% admixture of γ 5 coupling for the pion, and a second with six mesons (π,σ,/rho/,ω,δ,/eta/) but pure γ 5 γ/sup μ/ pion coupling, are shown to give very good quantitative fits to the NN scattering phase shifts below 400 MeV, and also a good description of the /rvec p/ 40 Ca elastic scattering observables. Applications of this model to electromagnetic interactions of the two body system, with emphasis on the determination of relativistic current operators consistent with the dynamics and the exact treatment of current conservation in the presence of phenomenological form factors, will be described. 18 refs., 8 figs

The dynamic multisite interactions between two intrinsically disordered proteins

KAUST Repository

Wu, Shaowen

2017-05-11

Protein interactions involving intrinsically disordered proteins (IDPs) comprise a variety of binding modes, from the well characterized folding upon binding to dynamic fuzzy complex. To date, most studies concern the binding of an IDP to a structured protein, while the Interaction between two IDPs is poorly understood. In this study, we combined NMR, smFRET, and molecular dynamics (MD) simulation to characterize the interaction between two IDPs, the C-terminal domain (CTD) of protein 4.1G and the nuclear mitotic apparatus (NuMA) protein. It is revealed that CTD and NuMA form a fuzzy complex with remaining structural disorder. Multiple binding sites on both proteins were identified by MD and mutagenesis studies. Our study provides an atomic scenario in which two IDPs bearing multiple binding sites interact with each other in dynamic equilibrium. The combined approach employed here could be widely applicable for investigating IDPs and their dynamic interactions.

Out of my real body. Cognitive Neuroscience meets Eating Disorders

Directory of Open Access Journals (Sweden)

Giuseppe eRiva

2014-05-01

Full Text Available Clinical psychology is starting to explain eating disorders (ED as the outcome of the interaction among cognitive, socio-emotional and interpersonal elements. In particular two influential models - the revised cognitive-interpersonal maintenance model and the transdiagnostic cognitive behavioral theory – identified possible key predisposing and maintaining factors. These models, even if very influential and able to provide clear suggestions for therapy, still are not able to provide answers to several critical questions: Why do not all the individuals with obsessive compulsive features, anxious avoidance or with a dysfunctional scheme for self-evaluation develop an eating disorder? What is the role of the body experience in the etiology of these disorders?In this paper we suggest that a meaningful answer requires the integration of these models with the recent outcomes of cognitive neuroscience. First, our bodily representations are not just a way to map an external space but the main tool we use to generate meaning, organize our experience, and shape our social identity. In particular, we will argue that our bodily experience evolves over time by integrating six different representations of the body characterized by specific pathologies – body schema (phantom limb, spatial body (unilateral hemi-neglect, active body (alien hand syndrome, personal body (autoscopic phenomena, objectified body (xenomelia and body image (body dysmorphia. Second, these representations include either schematic (allocentric or perceptual (egocentric contents that interact within the working memory of the individual through the alignment between the retrieved contents from long-term memory and the ongoing egocentric contents from perception. In this view eating disorders may be the outcome of an impairment in the ability of updating a negative body representation stored in autobiographical memory (allocentric with real-time sensorimotor and proprioceptive data

Out of my real body: cognitive neuroscience meets eating disorders

Science.gov (United States)

Riva, Giuseppe

2014-01-01

Clinical psychology is starting to explain eating disorders (ED) as the outcome of the interaction among cognitive, socio-emotional and interpersonal elements. In particular two influential models—the revised cognitive-interpersonal maintenance model and the transdiagnostic cognitive behavioral theory—identified possible key predisposing and maintaining factors. These models, even if very influential and able to provide clear suggestions for therapy, still are not able to provide answers to several critical questions: why do not all the individuals with obsessive compulsive features, anxious avoidance or with a dysfunctional scheme for self-evaluation develop an ED? What is the role of the body experience in the etiology of these disorders? In this paper we suggest that the path to a meaningful answer requires the integration of these models with the recent outcomes of cognitive neuroscience. First, our bodily representations are not just a way to map an external space but the main tool we use to generate meaning, organize our experience, and shape our social identity. In particular, we will argue that our bodily experience evolves over time by integrating six different representations of the body characterized by specific pathologies—body schema (phantom limb), spatial body (unilateral hemi-neglect), active body (alien hand syndrome), personal body (autoscopic phenomena), objectified body (xenomelia) and body image (body dysmorphia). Second, these representations include either schematic (allocentric) or perceptual (egocentric) contents that interact within the working memory of the individual through the alignment between the retrieved contents from long-term memory and the ongoing egocentric contents from perception. In this view EDs may be the outcome of an impairment in the ability of updating a negative body representation stored in autobiographical memory (allocentric) with real-time sensorimotor and proprioceptive data (egocentric). PMID:24834042

Out of my real body: cognitive neuroscience meets eating disorders.

Science.gov (United States)

Riva, Giuseppe

2014-01-01

Clinical psychology is starting to explain eating disorders (ED) as the outcome of the interaction among cognitive, socio-emotional and interpersonal elements. In particular two influential models-the revised cognitive-interpersonal maintenance model and the transdiagnostic cognitive behavioral theory-identified possible key predisposing and maintaining factors. These models, even if very influential and able to provide clear suggestions for therapy, still are not able to provide answers to several critical questions: why do not all the individuals with obsessive compulsive features, anxious avoidance or with a dysfunctional scheme for self-evaluation develop an ED? What is the role of the body experience in the etiology of these disorders? In this paper we suggest that the path to a meaningful answer requires the integration of these models with the recent outcomes of cognitive neuroscience. First, our bodily representations are not just a way to map an external space but the main tool we use to generate meaning, organize our experience, and shape our social identity. In particular, we will argue that our bodily experience evolves over time by integrating six different representations of the body characterized by specific pathologies-body schema (phantom limb), spatial body (unilateral hemi-neglect), active body (alien hand syndrome), personal body (autoscopic phenomena), objectified body (xenomelia) and body image (body dysmorphia). Second, these representations include either schematic (allocentric) or perceptual (egocentric) contents that interact within the working memory of the individual through the alignment between the retrieved contents from long-term memory and the ongoing egocentric contents from perception. In this view EDs may be the outcome of an impairment in the ability of updating a negative body representation stored in autobiographical memory (allocentric) with real-time sensorimotor and proprioceptive data (egocentric).

Ana3 is a conserved protein required for the structural integrity of centrioles and basal bodies.

Science.gov (United States)

Stevens, Naomi R; Dobbelaere, Jeroen; Wainman, Alan; Gergely, Fanni; Raff, Jordan W

2009-11-02

Recent studies have identified a conserved "core" of proteins that are required for centriole duplication. A small number of additional proteins have recently been identified as potential duplication factors, but it is unclear whether any of these proteins are components of the core duplication machinery. In this study, we investigate the function of one of these proteins, Drosophila melanogaster Ana3. We show that Ana3 is present in centrioles and basal bodies, but its behavior is distinct from that of the core duplication proteins. Most importantly, we find that Ana3 is required for the structural integrity of both centrioles and basal bodies and for centriole cohesion, but it is not essential for centriole duplication. We show that Ana3 has a mammalian homologue, Rotatin, that also localizes to centrioles and basal bodies and appears to be essential for cilia function. Thus, Ana3 defines a conserved family of centriolar proteins and plays an important part in ensuring the structural integrity of centrioles and basal bodies.

Social interactions through the eyes of macaques and humans.

Directory of Open Access Journals (Sweden)

Richard McFarland

Full Text Available Group-living primates frequently interact with each other to maintain social bonds as well as to compete for valuable resources. Observing such social interactions between group members provides individuals with essential information (e.g. on the fighting ability or altruistic attitude of group companions to guide their social tactics and choice of social partners. This process requires individuals to selectively attend to the most informative content within a social scene. It is unclear how non-human primates allocate attention to social interactions in different contexts, and whether they share similar patterns of social attention to humans. Here we compared the gaze behaviour of rhesus macaques and humans when free-viewing the same set of naturalistic images. The images contained positive or negative social interactions between two conspecifics of different phylogenetic distance from the observer; i.e. affiliation or aggression exchanged by two humans, rhesus macaques, Barbary macaques, baboons or lions. Monkeys directed a variable amount of gaze at the two conspecific individuals in the images according to their roles in the interaction (i.e. giver or receiver of affiliation/aggression. Their gaze distribution to non-conspecific individuals was systematically varied according to the viewed species and the nature of interactions, suggesting a contribution of both prior experience and innate bias in guiding social attention. Furthermore, the monkeys' gaze behavior was qualitatively similar to that of humans, especially when viewing negative interactions. Detailed analysis revealed that both species directed more gaze at the face than the body region when inspecting individuals, and attended more to the body region in negative than in positive social interactions. Our study suggests that monkeys and humans share a similar pattern of role-sensitive, species- and context-dependent social attention, implying a homologous cognitive mechanism of

A STE12 homologue of the homothallic ascomycete Sordaria macrospora interacts with the MADS box protein MCM1 and is required for ascosporogenesis.

Science.gov (United States)

Nolting, Nicole; Pöggeler, Stefanie

2006-11-01

The MADS box protein MCM1 controls diverse developmental processes and is essential for fruiting body formation in the homothallic ascomycete Sordaria macrospora. MADS box proteins derive their regulatory specificity from a wide range of different protein interactions. We have recently shown that the S. macrospora MCM1 is able to interact with the alpha-domain mating-type protein SMTA-1. To further evaluate the functional roles of MCM1, we used the yeast two-hybrid approach to identify MCM1-interacting proteins. From this screen, we isolated a protein with a putative N-terminal homeodomain and C-terminal C2/H2-Zn2+ finger domains. The protein is a member of the highly conserved fungal STE12 transcription factor family of proteins and was therefore termed STE12. Furthermore, we demonstrate by means of two-hybrid and far western analysis that in addition to MCM1, the S. macrospora STE12 protein is able to interact with the mating-type protein SMTA-1. Unlike the situation in the closely related heterothallic ascomycete Neurospora crassa, deletion (Delta) of the ste12 gene in S. macrospora neither affects vegetative growth nor fruiting body formation. However, ascus and ascospore development are highly impaired by the Deltaste12 mutation. Our data provide another example of the functional divergence within the fungal STE12 transcription factor family.

Chiral Floquet Phases of Many-Body Localized Bosons

Directory of Open Access Journals (Sweden)

Hoi Chun Po

2016-12-01

Full Text Available We construct and classify chiral topological phases in driven (Floquet systems of strongly interacting bosons, with finite-dimensional site Hilbert spaces, in two spatial dimensions. The construction proceeds by introducing exactly soluble models with chiral edges, which in the presence of many-body localization (MBL in the bulk are argued to lead to stable chiral phases. These chiral phases do not require any symmetry and in fact owe their existence to the absence of energy conservation in driven systems. Surprisingly, we show that they are classified by a quantized many-body index, which is well defined for any MBL Floquet system. The value of this index, which is always the logarithm of a positive rational number, can be interpreted as the entropy per Floquet cycle pumped along the edge, formalizing the notion of quantum-information flow. We explicitly compute this index for specific models and show that the nontrivial topology leads to edge thermalization, which provides an interesting link between bulk topology and chaos at the edge. We also discuss chiral Floquet phases in interacting fermionic systems and their relation to chiral bosonic phases.

Nuclear structure calculations in the dynamic-interaction propagator approach

International Nuclear Information System (INIS)

Engelbrecht, C.A.; Hahne, F.J.W.; Heiss, W.D.

1978-01-01

The dynamic-interaction propagator approach provides a natural method for the handling of energy-dependent effective two-body interactions induced by collective excitations of a many-body system. In this work this technique is applied to the calculation of energy spectra and two-particle strengths in mass-18 nuclei. The energy dependence is induced by the dynamic exchange of the lowest 3 - octupole phonon in O 16 , which is described within a normal static particle-hole RPA. This leads to poles in the two-body self-energy, which can be calculated if other fermion lines are restricted to particle states. The two-body interaction parameters are chosen to provide the correct phonon energy and reasonable negative-parity mass-17 and positive-parity mass-18 spectra. The fermion lines must be dressed consistently with the same exchange phonon to avoid redundant solutions or ghosts. The negative-parity states are then calculated in a parameter-free way which gives good agreement with the observed spectra [af

Modified Kepler's law, escape speed, and two-body problem in modified Newtonian dynamics-like theories

International Nuclear Information System (INIS)

Zhao Hongsheng; Li Baojiu; Bienayme, Olivier

2010-01-01

We derive a simple analytical expression for the two-body force in a subclass of modified Newtonian dynamics (MOND) theories and make testable predictions in the modification to the two-body orbital period, shape, precession rate, escape speed, etc. We demonstrate the applications of the modified Kepler's law in the timing of satellite orbits around the Milky Way, and checking the feasibility of MOND in the orbit of the large Magellanic cloud, the M31 galaxy, and the merging bullet clusters. MOND appears to be consistent with satellite orbits although with a tight margin. Our results on two-bodies are also generalized to restricted three-body, many-body problems, rings, and shells.

Many-body physics with circuit quantum electrodynamics

International Nuclear Information System (INIS)

Leib, Martin H.

2015-01-01

We present proposals to simulate many-body physics with superconducting circuits. The ''body'' to work with for superconducting circuits is the microwave photon and interaction is induced by the nonlinearity of the Josephson effect. We present two different approaches to simulate Bose-Hubbard physics, one based on a polariton scheme and another with nonlinear resonators. We also present a Dicke-model like simulator for ultrastrongly coupled Josephson junctions to a resonator and show a scheme for implementing long range interactions.

Human Body 3D Posture Estimation Using Significant Points and Two Cameras

Science.gov (United States)

Juang, Chia-Feng; Chen, Teng-Chang; Du, Wei-Chin

2014-01-01

This paper proposes a three-dimensional (3D) human posture estimation system that locates 3D significant body points based on 2D body contours extracted from two cameras without using any depth sensors. The 3D significant body points that are located by this system include the head, the center of the body, the tips of the feet, the tips of the hands, the elbows, and the knees. First, a linear support vector machine- (SVM-) based segmentation method is proposed to distinguish the human body from the background in red, green, and blue (RGB) color space. The SVM-based segmentation method uses not only normalized color differences but also included angle between pixels in the current frame and the background in order to reduce shadow influence. After segmentation, 2D significant points in each of the two extracted images are located. A significant point volume matching (SPVM) method is then proposed to reconstruct the 3D significant body point locations by using 2D posture estimation results. Experimental results show that the proposed SVM-based segmentation method shows better performance than other gray level- and RGB-based segmentation approaches. This paper also shows the effectiveness of the 3D posture estimation results in different postures. PMID:24883422

On singular interaction potentials in classical statistical mechanics

International Nuclear Information System (INIS)

Zagrebnov, V.A.; Pastur, L.A.

1978-01-01

A classical system of particles with stable two-body interaction potential is considered. It is shown that for a certain class of highly singular stable two-body potentials a cut-off procedure preserves the stability of the potential. The thermodynamical potentials (pressure and free energy density) and correlation functions are proved to have the property of asymptotic independence with respect to the continuation of the interaction potentials near singularity

The N-Terminal of Aquareovirus NS80 Is Required for Interacting with Viral Proteins and Viral Replication.

Directory of Open Access Journals (Sweden)

Jie Zhang

Full Text Available Reovirus replication and assembly occurs within viral inclusion bodies that formed in specific intracellular compartments of cytoplasm in infected cells. Previous study indicated that aquareovirus NS80 is able to form inclusion bodies, and also can retain viral proteins within its inclusions. To better understand how NS80 performed in viral replication and assembly, the functional regions of NS80 associated with other viral proteins in aquareovirus replication were investigated in this study. Deletion mutational analysis and rotavirus NSP5-based protein association platform were used to detect association regions. Immunofluorescence images indicated that different N-terminal regions of NS80 could associate with viral proteins VP1, VP4, VP6 and NS38. Further co-immunoprecipitation analysis confirmed the interaction between VP1, VP4, VP6 or NS38 with different regions covering the N-terminal amino acid (aa, 1-471 of NS80, respectively. Moreover, removal of NS80 N-terminal sequences required for interaction with proteins VP1, VP4, VP6 or NS38 not only prevented the capacity of NS80 to support viral replication in NS80 shRNA-based replication complementation assays, but also inhibited the expression of aquareovirus proteins, suggesting that N-terminal regions of NS80 are necessary for viral replication. These results provided a foundational basis for further understanding the role of NS80 in viral replication and assembly during aquareovirus infection.

General method for reducing the two-body Dirac equation

International Nuclear Information System (INIS)

Galeao, A.P.; Ferreira, P.L.

1992-01-01

A semi relativistic two-body Dirac equation with an enlarged set of phenomenological potentials, including Breit-type terms, is investigated for the general case of unequal masses. Solutions corresponding to definite total angular momentum and parity are shown to fall into two classes, each one being obtained by solving a system of four coupled first-order radial differential equations. The reduction of each of these systems to a pair of coupled Schroedinger-type equations is also discussed. (author)

Ground-state energy of the interacting Bose gas in two dimensions: An explicit construction

International Nuclear Information System (INIS)

Beane, Silas R.

2010-01-01

The isotropic scattering phase shift is calculated for nonrelativistic bosons interacting at low energies via an arbitrary finite-range potential in d space-time dimensions. Scattering on a (d-1)-dimensional torus is then considered, and the eigenvalue equation relating the energy levels on the torus to the scattering phase shift is derived. With this technology in hand, and focusing on the case of two spatial dimensions, a perturbative expansion is developed for the ground-state energy of N identical bosons which interact via an arbitrary finite-range potential in a finite area. The leading nonuniversal effects due to range corrections and three-body forces are included. It is then shown that the thermodynamic limit of the ground-state energy in a finite area can be taken in closed form to obtain the energy per particle in the low-density expansion by explicitly summing the parts of the finite-area energy that diverge with powers of N. The leading and subleading finite-size corrections to the thermodynamic limit equation of state are also computed. Closed-form results--some well known, others perhaps not--for two-dimensional lattice sums are included in an Appendix.

Centrobin–tubulin interaction is required for centriole elongation and stability

Science.gov (United States)

Gudi, Radhika; Zou, Chaozhong; Li, Jun

2011-01-01

Centrobin is a daughter centriole protein that is essential for centrosome duplication. However, the molecular mechanism by which centrobin functions during centriole duplication remains undefined. In this study, we show that centrobin interacts with tubulin directly, and centrobin–tubulin interaction is pivotal for the function of centrobin during centriole duplication. We found that centrobin is recruited to the centriole biogenesis site via its interaction with tubulins during the early stage of centriole biogenesis, and its recruitment is dependent on hSAS-6 but not centrosomal P4.1–associated protein (CPAP) and CP110. The function of centrobin is also required for the elongation of centrioles, which is likely mediated by its interaction with tubulin. Furthermore, disruption of centrobin–tubulin interaction led to destabilization of existing centrioles and the preformed procentriole-like structures induced by CPAP expression, indicating that centrobin–tubulin interaction is critical for the stability of centrioles. Together, our study demonstrates that centrobin facilitates the elongation and stability of centrioles via its interaction with tubulins. PMID:21576394

Environmental heterogeneity generates opposite gene-by-environment interactions for two fitness-related traits within a population.

Science.gov (United States)

Culumber, Zachary W; Schumer, Molly; Monks, Scott; Tobler, Michael

2015-02-01

Theory predicts that environmental heterogeneity offers a potential solution to the maintenance of genetic variation within populations, but empirical evidence remains sparse. The live-bearing fish Xiphophorus variatus exhibits polymorphism at a single locus, with different alleles resulting in up to five distinct melanistic "tailspot" patterns within populations. We investigated the effects of heterogeneity in two ubiquitous environmental variables (temperature and food availability) on two fitness-related traits (upper thermal limits and body condition) in two different tailspot types (wild-type and upper cut crescent). We found gene-by-environment (G × E) interactions between tailspot type and food level affecting upper thermal limits (UTL), as well as between tailspot type and thermal environment affecting body condition. Exploring mechanistic bases underlying these G × E patterns, we found no differences between tailspot types in hsp70 gene expression despite significant overall increases in expression under both thermal and food stress. Similarly, there was no difference in routine metabolic rates between the tailspot types. The reversal of relative performance of the two tailspot types under different environmental conditions revealed a mechanism by which environmental heterogeneity can balance polymorphism within populations through selection on different fitness-related traits. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

General relativistic dynamics of an extreme mass-ratio binary interacting with an external body

Science.gov (United States)

Yang, Huan; Casals, Marc

2017-10-01

We study the dynamics of a hierarchical three-body system in the general relativistic regime: an extreme mass-ratio inner binary under the tidal influence of an external body. The inner binary consists of a central Schwarzschild black hole and a test body moving around it. We discuss three types of tidal effects on the orbit of the test body. First, the angular momentum of the inner binary precesses around the angular momentum of the outer binary. Second, the tidal field drives a "transient resonance" when the radial and azimuthal frequencies are commensurable. In contrast with resonances driven by the gravitational self-force, this tidal-driven resonance may boost the orbital angular momentum and eccentricity (a relativistic version of the Kozai-Lidov effect). Finally, for an orbit-dynamical effect during the nonresonant phase, we calculate the correction to the innermost stable circular (mean) orbit due to the tidal interaction. Hierarchical three-body systems are potential sources for future space-based gravitational wave missions, and the tidal effects that we find could contribute significantly to their waveform.

Successful Surgical Correction of a Mesenteric Volvulus with Concurrent Foreign Body Obstruction in Two Puppies.

Science.gov (United States)

Jones, Susan; Friedenberg, Steven G; Callard, Jason; Abernathy, Leslie; Guillaumin, Julien

A 9 mo old female intact English mastiff (case 1) presented for anorexia and vomiting for 7 days. A 7 mo old male castrated American bulldog (case 2) presented for vomiting and anorexia for 2 days without diarrhea. Both dogs were diagnosed with mesenteric volvulus based on exploratory laparotomy, which also revealed an intestinal foreign body obstruction. Case 1 required critical care support during recovery but was ultimately discharged, whereas case 2 had an uncomplicated recovery. Both were reported to be back to normal 1 wk after surgery. Case 1 survived 3 mo and then died due to a colonic torsion diagnosed by exploratory laparotomy. Case 2 has been reported to be completely normal more than 18 mo after surgery. These two cases illustrate that mesenteric volvulus can be present with a several-day history of gastrointestinal signs and that shock may be absent on presentation. This is also the first published report of mesenteric volvulus with a concurrent foreign body obstruction.

Sas-4 proteins are required during basal body duplication in Paramecium

Science.gov (United States)

Gogendeau, Delphine; Hurbain, Ilse; Raposo, Graca; Cohen, Jean; Koll, France; Basto, Renata

2011-01-01

Centrioles and basal bodies are structurally related organelles composed of nine microtubule (MT) triplets. Studies performed in Caenorhabditis elegans embryos have shown that centriole duplication takes place in sequential way, in which different proteins are recruited in a specific order to assemble a procentriole. ZYG-1 initiates centriole duplication by triggering the recruitment of a complex of SAS-5 and SAS-6, which then recruits the final player, SAS-4, to allow the incorporation of MT singlets. It is thought that a similar mechanism (that also involves additional proteins) is present in other animal cells, but it remains to be investigated whether the same players and their ascribed functions are conserved during basal body duplication in cells that exclusively contain basal bodies. To investigate this question, we have used the multiciliated protist Paramecium tetraurelia. Here we show that in the absence of PtSas4, two types of defects in basal body duplication can be identified. In the majority of cases, the germinative disk and cartwheel, the first structures assembled during duplication, are not detected. In addition, if daughter basal bodies were formed, they invariably had defects in MT recruitment. Our results suggest that PtSas4 has a broader function than its animal orthologues. PMID:21289083

Repulsive interactions between two polyelectrolyte networks

Science.gov (United States)

Erbas, Aykut; Olvera de La Cruz, Monica; Olvera Group Collaboration

Surfaces formed by charged polymeric species are highly_abundant in both synthetic and biological systems, for which maintaining_an optimum contact distance and a pressure balance is paramount. We investigate interactions between surfaces of two same-charged and_highly swollen polyelectrolyte gels, using extensive molecular dynamic_simulations and minimal analytical methods. The external-pressure_responses of the gels and the polymer-free ionic solvent layer separating_two surfaces are considered. Simulations confirmed that the surfaces are_held apart by osmotic pressure resulting from excess charges diffusing out_of the network. Both the solvent layer and pressure dependence are well_described by an analytical model based on the Poisson -Boltzmann solution for low and moderate electrostatic strengths. Our results can be of great importance for systems where charged gels or gel-like structures interact in various solvents, including systems encapsulated by gels and microgels in confinement.

Sensorimotor body-environment interaction serves to regulate emotional experience and exploratory behavior

Directory of Open Access Journals (Sweden)

Martin Dobricki

2016-10-01

Full Text Available Almost all living species regularly explore environments that they experience as pleasant, aversive, arousing or frightening. We postulate that such exploratory behavior and emotional experience both are regulated based on the interdependent perception of one’s body and stimuli that collectively define a spatial context such as a cliff. Here we examined this by testing if the interaction of the sensory input on one’s gait and the sensory input on the spatial context is modulating both the emotional experience of the environment and its exploration through head motion. To this end, we asked healthy humans to explore a life-sized Virtual Reality simulation of a forest glade by physically walking around in this environment on two narrow rectangular platforms connected by a plank. The platforms and the plank were presented such that they were either placed on ground or on the top of two high bridge piers. Hence, the forest glade was presented either as a “ground” or as a “height” context. Within these two spatial contexts the virtual plank was projected either on the rigid physical floor or onto a bouncy physical plank. Accordingly, the gait of our participants while they crossed the virtual plank was either “smooth” or “bouncy.” We found that in the height context bouncy gait compared to smooth gait increased the orientation of the head below the horizon and intensified the experience of the environment as negative. Whereas, within the ground context bouncy gait increased the orientation of the head towards and above the horizon and made that the environment was experienced as positive. Our findings suggest that the brain of healthy humans is using the interaction of the sensory input on their gait and the sensory input on the spatial context to regulate both the emotional experience of the environment and its exploration through head motion. Keywords: Neuroscience, Psychology

Strongly interacting Fermi gases

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Bakr W.

2013-08-01

Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

Many-body perturbation theory for ab initio nuclear structure

International Nuclear Information System (INIS)

Tichai, Alexander

2017-01-01

The solution of the quantum many-body problem for medium-mass nuclei using realistic nuclear interactions poses a superbe challenge for nuclear structure research. Because an exact solution can only be provided for the lightest nuclei, one has to rely on approximate solutions when proceeding to heavier systems. Over the past years, tremendous progress has been made in the development and application of systematically improvable expansion methods and an accurate description of nuclear observables has become viable up to mass number A ∼ 100. While closed-shell systems are consistently described via a plethora of different many-body methods, the extension to genuine open-shell systems still remains a major challenge and up to now there is no ab initio many-body method which applies equally well to systems with even and odd mass numbers. The goal of this thesis is the development and implementation of innovative perturbative approaches with genuine open-shell capabilities. This requires the extension of well-known single-reference approaches to more general vacua. In this work we choose two complementary routes for the usage of generalized reference states. First, we derive a new ab initio approach based on multi-configurational reference states that are conveniently derived from a prior no-core shell model calculation. Perturbative corrections are derived via second-order many-body perturbation theory, thus, merging configuration interaction and many-body perturbation theory. The generality of this ansatz enables for a treatment of medium-mass systems with arbitrary mass number, as well as the extension to low-lying excited states such that ground and excited states are treated on an equal footing. In a complementary approach, we use reference states that break a symmetry of the underlying Hamiltonian. In the simplest case this corresponds to the expansion around a particle-number-broken Hartree-Fock-Bogolyubov vacuum which is obtained from a mean-field calculation

A numerical study of two interacting coronal mass ejections

Directory of Open Access Journals (Sweden)

J. M. Schmidt

2004-06-01

Full Text Available The interaction in the solar wind between two coronal mass ejections (CMEs is investigated using numerical simulations. We show that the nature of the interaction depends on whether the CME magnetic structures interact, but in all cases the result is an equilisation of the speed of the two CMEs. In the absence of magnetic interaction, the forward shock of the faster trailing CME interacts with the slow leading CME, and accelerates it. When the two CMEs have magnetic fields with the same sense of rotation, magnetic reconnection occurs between the two CMEs, leading to the formation of a single magnetic structure: in the most extreme cases, one CME "eats" the other. When the senses of rotation are opposite, reconnection does not occur, but the CMEs collide in a highly non-elastic manner, again forming a single structure. The possibility of enhanced particle acceleration in such processes is assessed. The presence of strong magnetic reconnection provides excellent opportunities for the acceleration of thermal particles, which then form a seed population for further acceleration at the CME shocks. The presence of a large population of seed particles will thus lead to an overall increase in energetic particle fluxes, as suggested by some observations.

Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, September 1, 1983-August 31, 1984

International Nuclear Information System (INIS)

Harper, E.P.; Lehman, D.R.; Prats, F.

1984-01-01

The George Washington University nuclear theory group proposes to conduct investigations of the structure and electromagnetic interactions of few-body systems. The structural properties of the very light nuclei are examined by developing theoretical models that begin from the basic interactions between the constituents and that are solved exactly (numerically), i.e., full three or four-body dynamics. Such models are then used in an attempt to understand the details of the strong and electromagnetic interactions of the few-nucleon nuclei after the basic underlying reaction mechanisms are understood with simpler models. Examples of specific work proposed are the following: (1) From exact four-body dynamics, derive the equations that will permit calculation of the 4 He→ 3 He+n and 4 He→d+d asymptotic normalization constants; (2) Develop a unified picture of the p + d → 3 He = γ, p + d → 3 He = π 0 , p + d → 3 H + π + reactions at intermediate energies; (3) Calculate the elastic and inelastic (1 + →0 + ) form factors for 6 Li with three-body (αNN) wave functions; (4) Calculate static properties (RMS radius, magnetic moment, and quadrupole moment) of 6 Li with three-body wave functions; and (5) Develop the theory for the coincidence reactions 6 Li(p,2p)nα, 6 Li(e,e'p)nα, and 6 Li(e,e'd)α. It is anticipated that these efforts will expand the frontiers of our knowledge about few-body nuclei

Problems of organization of interaction of administrative bodies and the forces engaged in liquidation of after-effects of radiation accident

International Nuclear Information System (INIS)

Popov, A.P.; Perevezentsev, A.M.

1995-01-01

The paper defines the main problems arising in connection with organization of interaction of the administrative bodies and the forces involved in liquidation of after-effects of radiation accident. It is demonstrated that in order to increase the efficiency of interaction of the administrative bodies of various levels it is necessary to make it automatic. The paper revealed the meaning of the levels of relationship between various automatic systems. 4 refs

Two-body correlation functions in dilute nuclear matter

International Nuclear Information System (INIS)

Isayev, A A

2006-01-01

Finding the distinct features of the crossover from the regime of large overlapping Cooper pairs to the limit of non-overlapping pairs of fermions (Shafroth pairs) in multicomponent Fermi systems remains one of the actual problems in a quantum many-body theory. Here this transition is studied by calculating the two-body density, spin and isospin correlation functions in dilute asymmetric nuclear matter. It is shown that criterion of the crossover (Phys. Rev. Lett. 95, 090402 (2005)), consisting in the change of the sign of the density correlation function at low momentum transfer, fails to describe correctly the density-driven BEC-BCS transition at finite isospin asymmetry or finite temperature. As an unambiguous signature of the BEC-BCS transition, there can be used the presence (BCS regime) or absence (BEC regime) of the singularity in the momentum distribution of the quasiparticle density of states

Electroproduction of associated two-body final states

International Nuclear Information System (INIS)

Harding, D.J.

1983-01-01

The Large Aperture Magnet Experiment at the Cornell Electron Synchrotron measured electron scattering in the region 2.98 2 and 0.5 2 2 . The 11.5 GeV extracted electron beam struck a liquid hydrogen target in an eight kilogauss magnetic field. The charged particles in the final state were tracked through the field by a multiwire proportional chamber system of 34 planes. A lead-scintillator shower counter triggered the experiment on detection of a scattered electron. Time-of-flight and water Cherenkov counters identified some of the final state hadrons. The data recorded on tape was then passed through computer programs which linked proportional chamber strikes into tracks, fit momenta to the tracks, applied particle identification algorithms, selected interesting events, and plotted histograms of invariant masses. All of this is described here in detail, with special attention to the front-end electronics and the track-finding program. Many specific final states were observed. The analysis presented here concentrates on the reaction γ/sub v/p→pπ + ππ 0 , with the final hadrons resulting from the decay of a two-body state. The states pω 0 and p eta 0 are measured. Limits are set for the production of Δ + + rho - , Δ + rho 0 , and Δp + . The conclusion the author draws is that hadron-like two-body processes are almost completely absent in virtual photon scattering in this kinematic region. Vector meson production, excitation of the nucleons, and the scattering of the photons directly from individual partons are the important processes

Real-Time, Interactive Echocardiography Over High-Speed Networks: Feasibility and Functional Requirements

Science.gov (United States)

Bobinsky, Eric A.

1998-01-01

Real-time, Interactive Echocardiography Over High Speed Networks: Feasibility and Functional Requirements is an experiment in advanced telemedicine being conducted jointly by the NASA Lewis Research Center, the NASA Ames Research Center, and the Cleveland Clinic Foundation. In this project, a patient undergoes an echocardiographic examination in Cleveland while being diagnosed remotely by a cardiologist in California viewing a real-time display of echocardiographic video images transmitted over the broadband NASA Research and Education Network (NREN). The remote cardiologist interactively guides the sonographer administering the procedure through a two-way voice link between the two sites. Echocardiography is a noninvasive medical technique that applies ultrasound imaging to the heart, providing a "motion picture" of the heart in action. Normally, echocardiographic examinations are performed by a sonographer and cardiologist who are located in the same medical facility as the patient. The goal of telemedicine is to allow medical specialists to examine patients located elsewhere, typically in remote or medically underserved geographic areas. For example, a small, rural clinic might have access to an echocardiograph machine but not a cardiologist. By connecting this clinic to a major metropolitan medical facility through a communications network, a minimally trained technician would be able to carry out the procedure under the supervision and guidance of a qualified cardiologist.

Three-body forces: a status report

International Nuclear Information System (INIS)

Coon, S.A.

1976-01-01

Real three-body forces due to meson exchange are distinguished from effective three-body interactions of a nuclear Hamiltonian. The long-range part of the real three-body force is proportional to the off-mass-shell sup(PI)N scattering amplitude. Its contribution to the binding energy of nuclear matter is quite dependent upon the treatment of correlations (due to the two-body potential) in the three-body wave function. A recent improvemrnt in the amplitude implies a very small contribution. But, a recent improvement in the treatment of correlations implies a large contribution. Work towards including both these improvements in a single calculation is in progress. (author)

The mind body problem: the hermeneutics of African philosophy ...

African Journals Online (AJOL)

Philosophers of different ages, epochs and ideological orientations have engaged themselves in a heated debate on the issue of the mind- body interaction. Indeed, there are two different but interactive entities in man with different modes of action yet interacting in themost subtlemanner as to produce in aman , amind able ...

Optical tweezers for measuring the interaction of the two single red blood cells in flow condition

Science.gov (United States)

Lee, Kisung; Muravyov, Alexei; Semenov, Alexei; Wagner, Christian; Priezzhev, Alexander

2017-03-01

Aggregation of red blood cells (RBCs) is an intrinsic property of blood, which has direct effect on the blood viscosity and therefore affects overall the blood circulation throughout the body. It is attracting interest for the research in both fundamental science and clinical application. Despite of the intensive research, the aggregation mechanism is remaining not fully clear. Recent advances in methods allowed measuring the interaction between single RBCs in a well-defined configuration leading the better understanding of the mechanism of the process. However the most of the studies were made on the static cells. Thus, the measurements in flow mimicking conditions are missing. In this work, we aim to study the interaction of two RBCs in the flow conditions. We demonstrate the characterization of the cells interaction strength (or flow tolerance) by measuring the flow velocity to be applied to separate two aggregated cells trapped by double channel optical tweezers in a desired configuration. The age-separated cells were used for this study. The obtained values for the minimum flow velocities needed to separate the two cells were found to be 78.9 +/- 6.1 μm/s and 110 +/- 13 μm/s for old and young cells respectively. The data obtained is in agreement with the observations reported by other authors. The significance of our results is in ability for obtaining a comprehensible and absolute physical value characterizing the cells interaction in flow conditions (not like the Aggregation Index measured in whole blood suspensions by other techniques, which is some abstract parameter)

Two appendages homologous between basal bodies and centrioles are formed using distinct Odf2 domains.

Science.gov (United States)

Tateishi, Kazuhiro; Yamazaki, Yuji; Nishida, Tomoki; Watanabe, Shin; Kunimoto, Koshi; Ishikawa, Hiroaki; Tsukita, Sachiko

2013-11-11

Ciliogenesis is regulated by context-dependent cellular cues, including some transduced through appendage-like structures on ciliary basal bodies called transition fibers and basal feet. However, the molecular basis for this regulation is not fully understood. The Odf2 gene product, ODF2/cenexin, is essential for both ciliogenesis and the formation of the distal and subdistal appendages on centrioles, which become basal bodies. We examined the effects of Odf2 deletion constructs on ciliogenesis in Odf2-knockout F9 cells. Electron microscopy revealed that ciliogenesis and transition fiber formation required the ODF2/cenexin fragment containing amino acids (aa) 188-806, whereas basal foot formation required aa 1-59 and 188-806. These sequences also formed distal and subdistal appendages, respectively, indicating that the centriole appendages are molecularly analogous to those on basal bodies. We used the differential formation of appendages by Odf2 deletion constructs to study the incorporation and function of molecules associated with each appendage type. We found that transition fibers and distal appendages were required for ciliogenesis and subdistal appendages stabilized the centrosomal microtubules.

Elastic energy of the flux lines in the matter. The interaction energy

International Nuclear Information System (INIS)

Dolocan, Voicu

1999-01-01

A theoretical treatment of the interaction between the bodies, by using the elastic coupling through the flux lines, is presented. We show that the elastic coupling through the flux lines gives an interaction energy between two superconductor or magnetic pieces, which is inversely proportional to the distance between the two bodies. We extend this concept to the gravitational and electrical interaction. For the electrical interaction one obtains that the statics interaction energy is inversely proportional to the distance between the charges, as in the Coulomb's law, while the oscillatory interaction is inversely proportional to the third power of the distance between the charged particles. This means that at shorter distance an attraction between the two charged particles of the same sign, may appear if the oscillatory energy of interaction is larger than the statics energy of interaction. In addition, the oscillatory interaction appears only as a virtual process. We apply these results to the deuteron and to the electron pairs in superconductors. Also, for the gravitation one obtains that the interaction energy is inversely proportional to the distance between the centers of the two bodies as in Newton's law. (author)

Analysis of User Requirements in Interactive 3D Video Systems

Directory of Open Access Journals (Sweden)

Haiyue Yuan

2012-01-01

Full Text Available The recent development of three dimensional (3D display technologies has resulted in a proliferation of 3D video production and broadcasting, attracting a lot of research into capture, compression and delivery of stereoscopic content. However, the predominant design practice of interactions with 3D video content has failed to address its differences and possibilities in comparison to the existing 2D video interactions. This paper presents a study of user requirements related to interaction with the stereoscopic 3D video. The study suggests that the change of view, zoom in/out, dynamic video browsing, and textual information are the most relevant interactions with stereoscopic 3D video. In addition, we identified a strong demand for object selection that resulted in a follow-up study of user preferences in 3D selection using virtual-hand and ray-casting metaphors. These results indicate that interaction modality affects users’ decision of object selection in terms of chosen location in 3D, while user attitudes do not have significant impact. Furthermore, the ray-casting-based interaction modality using Wiimote can outperform the volume-based interaction modality using mouse and keyboard for object positioning accuracy.

Ionization due to the interaction between two Rydberg atoms

International Nuclear Information System (INIS)

Robicheaux, F

2005-01-01

Using a classical trajectory Monte Carlo method, we have computed the ionization resulting from the interaction between two cold Rydberg atoms. We focus on the products resulting from close interaction between two highly excited atoms. We give information on the distribution of ejected electron energies, the distribution of internal atom energies and the velocity distribution of the atoms and ions after the ionization. If the potential for the atom is not purely Coulombic, the average interaction between two atoms can change from attractive to repulsive giving a Van de Graaff-like mechanism for accelerating atoms. In a small fraction of ionization cases, we find that the ionization leads to a positive molecular ion where all of the distances are larger than 1000 Bohr radii

Shape space figure-8 solution of three body problem with two equal masses

Science.gov (United States)

Yu, Guowei

2017-06-01

In a preprint by Montgomery (https://people.ucsc.edu/~rmont/Nbdy.html), the author attempted to prove the existence of a shape space figure-8 solution of the Newtonian three body problem with two equal masses (it looks like a figure 8 in the shape space, which is different from the famous figure-8 solution with three equal masses (Chenciner and Montgomery 2000 Ann. Math. 152 881-901)). Unfortunately there is an error in the proof and the problem is still open. Consider the α-homogeneous Newton-type potential, 1/rα, using action minimization method, we prove the existence of this solution, for α \\in (1, 2) ; for α=1 (the Newtonian potential), an extra condition is required, which unfortunately seems hard to verify at this moment.

Study on the Interaction between Two Hydrokinetic Savonius Turbines

Directory of Open Access Journals (Sweden)

Kailash Golecha

2012-01-01

Full Text Available Savonius turbine is simple in design and easy to fabricate at a lower cost. The drag is the basic driving force for Savonius turbine. Savonius turbines are mainly used for the small-scale electricity generation in remote areas. In real life, multiple Savonius turbines are to be arranged to form a farm to scale up the electricity generation. So, it is important to study the interaction among them to avoid the power loss due to negative interaction between turbines. The purpose of this investigation is to examine closely the effect of interaction between two Savonius turbines arranged in line. Experimental investigations are carried out to study the mutual interaction between turbines with water as the working medium at a Reynolds number of 1.2×105 based on the diameter of the turbine. Influence of separation gap between the two Savonius turbines is studied by varying the separation gap ratio (/ from 3 to 8. As the separation gap ratio increases from 3 to 8, becomes lesser the mutual interaction between the turbines. Results conclude that two turbines placed at a separation gap ratio of 8 performed independently without affecting the performance of each other.

Context generalization in Drosophila visual learning requires the mushroom bodies

Science.gov (United States)

Liu, Li; Wolf, Reinhard; Ernst, Roman; Heisenberg, Martin

1999-08-01

The world is permanently changing. Laboratory experiments on learning and memory normally minimize this feature of reality, keeping all conditions except the conditioned and unconditioned stimuli as constant as possible. In the real world, however, animals need to extract from the universe of sensory signals the actual predictors of salient events by separating them from non-predictive stimuli (context). In principle, this can be achieved ifonly those sensory inputs that resemble the reinforcer in theirtemporal structure are taken as predictors. Here we study visual learning in the fly Drosophila melanogaster, using a flight simulator,, and show that memory retrieval is, indeed, partially context-independent. Moreover, we show that the mushroom bodies, which are required for olfactory but not visual or tactile learning, effectively support context generalization. In visual learning in Drosophila, it appears that a facilitating effect of context cues for memory retrieval is the default state, whereas making recall context-independent requires additional processing.

Entanglement between two interacting CFTs and generalized holographic entanglement entropy

International Nuclear Information System (INIS)

Mollabashi, Ali; Shiba, Noburo; Takayanagi, Tadashi

2014-01-01

In this paper we discuss behaviors of entanglement entropy between two interacting CFTs and its holographic interpretation using the AdS/CFT correspondence. We explicitly perform analytical calculations of entanglement entropy between two free scalar field theories which are interacting with each other in both static and time-dependent ways. We also conjecture a holographic calculation of entanglement entropy between two interacting N=4 super Yang-Mills theories by introducing a minimal surface in the S 5 direction, instead of the AdS 5 direction. This offers a possible generalization of holographic entanglement entropy

Synergistic effects of seasonal rainfall, parasites and demography on fluctuations in springbok body condition

Science.gov (United States)

Turner, Wendy C.; Versfeld, Wilferd D.; Kilian, J. Werner; Getz, Wayne M.

2011-01-01

Summary 1. Seasonality of rainfall can exert a strong influence on animal condition and on host-parasite interactions. The body condition of ruminants fluctuates seasonally in response to changes in energy requirements, foraging patterns and resource availability, and seasonal variation in parasite infections may further alter ruminant body condition. 2. This study disentangles effects of rainfall and gastrointestinal parasite infections on springbok (Antidorcas marsupialis) body condition and determines how these factors vary among demographic groups. 3. Using data from four years and three study areas, we investigated i) the influence of rainfall variation, demographic factors and parasite interactions on parasite prevalence or infection intensity, ii) whether parasitism or rainfall is a more important predictor of springbok body condition and iii) how parasitism and condition vary among study areas along a rainfall gradient. 4. We found that increased parasite intensity is associated with reduced body condition only for adult females. For all other demographic groups, body condition was significantly related to prior rainfall and not to parasitism. Rainfall lagged by two months had a positive effect on body condition. 5. Adult females showed evidence of a “periparturient rise” in parasite intensity, and had higher parasite intensity and lower body condition than adult males after parturition and during early lactation. After juveniles were weaned, adult females had lower parasite intensity than adult males. Sex differences in parasitism and condition may be due to differences between adult females and males in the seasonal timing of reproductive effort and its effects on host immunity, as well as documented sex differences in vulnerability to predation. 6. Our results highlight that parasites and the environment can synergistically affect host populations, but that these interactions might be masked by their interwoven relationships, their differential

Universality in low energy three-body systems

International Nuclear Information System (INIS)

Amorim, A.E.A.; Tomio, L; Frederico, T.

1997-01-01

The renormalizability of the quantum theory of non-relativistic three-body system with zero range interaction, warranties that all the low-energy three-body properties are well defined and the low-energy two-body and only one three-body physical information are known. Considering this observation, we have shown that the conditions for the occurrence of Efimov states can be easily reached with any model of short range potential where the three-body ground state and the corresponding binding energy of the subsystems are kept fixed. This approach was applied to the recently discovered halo nuclei. (author)

Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, 1 January 1980-1 October 1980

International Nuclear Information System (INIS)

1980-01-01

Considerable progress has been made on the long-range problems described in the original proposal document (1 February 1979 to 31 January 1980) and on the shorter-range problems described in the last renewal proposal (1 February 1980 to 31 January 1981). This progress concerns few-body structure problems (e.g., the existence of isobar components in 3 H, predictions of few-body-hypernuclei properties as a test of hyperon-nucleon interactions, investigation of the A = 6 ground states with exact three-body calculations, and the relation of triton D-state properties to the deuteron's D-state percentage) and electromagnetic properties and interactions of few-body nuclei (e.g., Coulomb effects in calculating and measuring asymptotic normalization constants, and γ + 3 He breakup reaction mechanisms at intermediate energies). Descriptions of the progress made indicate where each subject stands at present, and emphasize the significant results obtained. A publication list is attached

Standardization of a Volumetric Displacement Measurement for Two-Body Abrasion Scratch Test Data Analysis

Science.gov (United States)

Street, K. W. Jr.; Kobrick, R. L.; Klaus, D. M.

2011-01-01

A limitation has been identified in the existing test standards used for making controlled, two-body abrasion scratch measurements based solely on the width of the resultant score on the surface of the material. A new, more robust method is proposed for analyzing a surface scratch that takes into account the full three-dimensional profile of the displaced material. To accomplish this, a set of four volume- displacement metrics was systematically defined by normalizing the overall surface profile to denote statistically the area of relevance, termed the Zone of Interaction. From this baseline, depth of the trough and height of the plowed material are factored into the overall deformation assessment. Proof-of-concept data were collected and analyzed to demonstrate the performance of this proposed methodology. This technique takes advantage of advanced imaging capabilities that allow resolution of the scratched surface to be quantified in greater detail than was previously achievable. When reviewing existing data analysis techniques for conducting two-body abrasive scratch tests, it was found that the ASTM International Standard G 171 specified a generic metric based only on visually determined scratch width as a way to compare abraded materials. A limitation to this method was identified in that the scratch width is based on optical surface measurements, manually defined by approximating the boundaries, but does not consider the three-dimensional volume of material that was displaced. With large, potentially irregular deformations occurring on softer materials, it becomes unclear where to systematically determine the scratch width. Specifically, surface scratches on different samples may look the same from a top view, resulting in an identical scratch width measurement, but may vary in actual penetration depth and/or plowing deformation. Therefore, two different scratch profiles would be measured as having identical abrasion properties, although they differ

Effects of covariance and current conservation at few-body systems photo and electrodisintegration

International Nuclear Information System (INIS)

Nagorny, S.

1995-01-01

The two-body disintegration of nuclei 2 H and 3 He by photons and electrons are being examined. Full relativistic approach is used. It allows to take into account the nuclear structure, final state interaction (FSI), meson exchange current (MEC) and to satisfy the fundamental requirements of covariance and gauge invariance. It is shown that the accounting of fundamental properties of nuclear EM currents essentially changes the sensitivity of the observables to the nuclear structure and reaction mechanisms. copyright 1995 American Institute of Physics

Relativistic analysis of four-body final states

International Nuclear Information System (INIS)

Adhikari, S.K.

1977-01-01

The constraints of unitarity and analyticity on four-body final states are studied. It is shown that unitarity alone forces the amplitudes to be coherent and have singular behaviour. The implementation of unitarity with total energy analyticity yields a set of relativistic linear integral equations for the four-body amplitude. This is the minimal set consistent with quantum mechanics and also is the full dynamical set of equations with two-body separable interactions. These equations will provide important ingredients for the phenomenological analysis of four-body final states using the isobar model. (Auth.)

Dual-EEG of joint finger tapping: what can two interacting brains teach us about social interaction?

DEFF Research Database (Denmark)

Konvalinka, Ivana

-frequency analysis revealed a left-motor and right-frontal suppression at 10 Hz during task execution, when carrying the task out interactively in contrast with the uncoupled computer-driven task. We used machine-learning approaches to identify the brain signals driving the interaction. The raw-power at 10 Hz during...... tapping emanating from electrodes of member one and member two were used as features. We combined data from both participants in each pair, and applied logistic regression using feature selection in order to classify the two conditions. The first seven (frontal) electrodes consistently emerged as good...... classifiers, with 85-99% accuracy. There was a tendency for one member’s frontal electrodes to drive the classifier over the other’s, which predicted the leader of the interaction in 8/9 pairs. This study reveals new neural mechanisms underlying two-person interactions. It also shows how analyzing two...

GW-Bodies and P-Bodies Constitute Two Separate Pools of Sequestered Non-Translating RNAs.

Directory of Open Access Journals (Sweden)

Prajal H Patel

Full Text Available Non-translating RNAs that have undergone active translational repression are culled from the cytoplasm into P-bodies for decapping-dependent decay or for sequestration. Organisms that use microRNA-mediated RNA silencing have an additional pathway to remove RNAs from active translation. Consequently, proteins that govern microRNA-mediated silencing, such as GW182/Gw and AGO1, are often associated with the P-bodies of higher eukaryotic organisms. Due to the presence of Gw, these structures have been referred to as GW-bodies. However, several reports have indicated that GW-bodies have different dynamics to P-bodies. Here, we use live imaging to examine GW-body and P-body dynamics in the early Drosophila melanogaster embryo. While P-bodies are present throughout early embryonic development, cytoplasmic GW-bodies only form in significant numbers at the midblastula transition. Unlike P-bodies, which are predominantly cytoplasmic, GW-bodies are present in both nuclei and the cytoplasm. RNA decapping factors such as DCP1, Me31B, and Hpat are not associated with GW-bodies, indicating that P-bodies and GW-bodies are distinct structures. Furthermore, known Gw interactors such as AGO1 and the CCR4-NOT deadenylation complex, which have been shown to be important for Gw function, are also not present in GW-bodies. Use of translational inhibitors puromycin and cycloheximide, which respectively increase or decrease cellular pools of non-translating RNAs, alter GW-body size, underscoring that GW-bodies are composed of non-translating RNAs. Taken together, these data indicate that active translational silencing most likely does not occur in GW-bodies. Instead GW-bodies most likely function as repositories for translationally silenced RNAs. Finally, inhibition of zygotic gene transcription is unable to block the formation of either P-bodies or GW-bodies in the early embryo, suggesting that these structures are composed of maternal RNAs.

Understanding the many-body expansion for large systems. III. Critical role of four-body terms, counterpoise corrections, and cutoffs

Science.gov (United States)

Liu, Kuan-Yu; Herbert, John M.

2017-10-01

Papers I and II in this series [R. M. Richard et al., J. Chem. Phys. 141, 014108 (2014); K. U. Lao et al., ibid. 144, 164105 (2016)] have attempted to shed light on precision and accuracy issues affecting the many-body expansion (MBE), which only manifest in larger systems and thus have received scant attention in the literature. Many-body counterpoise (CP) corrections are shown to accelerate convergence of the MBE, which otherwise suffers from a mismatch between how basis-set superposition error affects subsystem versus supersystem calculations. In water clusters ranging in size up to (H2O)37, four-body terms prove necessary to achieve accurate results for both total interaction energies and relative isomer energies, but the sheer number of tetramers makes the use of cutoff schemes essential. To predict relative energies of (H2O)20 isomers, two approximations based on a lower level of theory are introduced and an ONIOM-type procedure is found to be very well converged with respect to the appropriate MBE benchmark, namely, a CP-corrected supersystem calculation at the same level of theory. Results using an energy-based cutoff scheme suggest that if reasonable approximations to the subsystem energies are available (based on classical multipoles, say), then the number of requisite subsystem calculations can be reduced even more dramatically than when distance-based thresholds are employed. The end result is several accurate four-body methods that do not require charge embedding, and which are stable in large basis sets such as aug-cc-pVTZ that have sometimes proven problematic for fragment-based quantum chemistry methods. Even with aggressive thresholding, however, the four-body approach at the self-consistent field level still requires roughly ten times more processors to outmatch the performance of the corresponding supersystem calculation, in test cases involving 1500-1800 basis functions.

Understanding the many-body expansion for large systems. III. Critical role of four-body terms, counterpoise corrections, and cutoffs.

Science.gov (United States)

Liu, Kuan-Yu; Herbert, John M

2017-10-28

Papers I and II in this series [R. M. Richard et al., J. Chem. Phys. 141, 014108 (2014); K. U. Lao et al., ibid. 144, 164105 (2016)] have attempted to shed light on precision and accuracy issues affecting the many-body expansion (MBE), which only manifest in larger systems and thus have received scant attention in the literature. Many-body counterpoise (CP) corrections are shown to accelerate convergence of the MBE, which otherwise suffers from a mismatch between how basis-set superposition error affects subsystem versus supersystem calculations. In water clusters ranging in size up to (H 2 O) 37 , four-body terms prove necessary to achieve accurate results for both total interaction energies and relative isomer energies, but the sheer number of tetramers makes the use of cutoff schemes essential. To predict relative energies of (H 2 O) 20 isomers, two approximations based on a lower level of theory are introduced and an ONIOM-type procedure is found to be very well converged with respect to the appropriate MBE benchmark, namely, a CP-corrected supersystem calculation at the same level of theory. Results using an energy-based cutoff scheme suggest that if reasonable approximations to the subsystem energies are available (based on classical multipoles, say), then the number of requisite subsystem calculations can be reduced even more dramatically than when distance-based thresholds are employed. The end result is several accurate four-body methods that do not require charge embedding, and which are stable in large basis sets such as aug-cc-pVTZ that have sometimes proven problematic for fragment-based quantum chemistry methods. Even with aggressive thresholding, however, the four-body approach at the self-consistent field level still requires roughly ten times more processors to outmatch the performance of the corresponding supersystem calculation, in test cases involving 1500-1800 basis functions.

Lah is a transmembrane protein and requires Spa10 for stable positioning of Woronin bodies at the septal pore of Aspergillus fumigatus.

Science.gov (United States)

Leonhardt, Yannik; Kakoschke, Sara Carina; Wagener, Johannes; Ebel, Frank

2017-03-10

Woronin bodies are specialized, fungal-specific organelles that enable an immediate closure of septal pores after injury to protect hyphae from excessive cytoplasmic bleeding. In most Ascomycetes, Woronin bodies are tethered at the septal pore by so-called Lah proteins. Using the pathogenic mold Aspergillus fumigatus as a model organism, we show that the C-terminal 288 amino acids of Lah (LahC 288 ) bind to the rim of the septal pore. LahC 288 essentially consists of a membrane spanning region and a putative extracellular domain, which are both required for the targeting to the septum. In an A. fumigatus rho4 deletion mutant that has a severe defect in septum formation, LahC 288 is recruited to spot-like structures in or at the lateral membrane. This suggests that LahC is recruited before Rho4 starts to govern the septation process. Accordingly, we found that in wild type hyphae Lah is bound before a cross-wall emerges and thus enables a tethering of Woronin bodies at the site of the newly formed septum. Finally, we identified Spa10, a member of a recently described family of septal pore-associated proteins, as a first protein that directly or indirectly interacts with LahC to allow a stable positioning of Woronin bodies at the mature septum.

Integral bounds for N-body total cross sections

International Nuclear Information System (INIS)

Osborn, T.A.; Bolle, D.

1979-01-01

We study the behavior of the total cross sections in the three- and N-body scattering problem. Working within the framework of the time-dependent two-Hilbert space scattering theory, we give a simple derivation of integral bounds for the total cross section for all processes initiated by the collision of two clusters. By combining the optical theorem with a trace identity derived by Jauch, Sinha, and Misra, we find, roughly speaking, that if the local pairwise interaction falls off faster than r -3 , then sigma/sub tot/(E) must decrease faster than E/sup -1/2/ at high energy. This conclusion is unchanged if one introduces a class of well-behaved three-body interactions

A two-level solvable model involving competing pairing interactions

International Nuclear Information System (INIS)

Dussel, G.G.; Maqueda, E.E.; Perazzo, R.P.J.; Evans, J.A.

1986-01-01

A model is considered consisting of nucleons moving in two non-degenerate l-shells and interacting through two pairing residual interactions with (S, T) = (1, 0) and (0, 1). These, together with the single particle hamiltonian induce mutually destructive correlations, giving rise to various collective pictures that can be discussed as representing a two-dimensional space of phases. The model is solved exactly using an O(8)xO(8) group theoretical classification scheme. The transfer of correlated pairs and quartets is also discussed. (orig.)

Nuclear shape evolution starting from superdeformed state. Role of two-body collision and rotation

International Nuclear Information System (INIS)

Liu, Yu-xin; Sakata, Fumihiko

1999-01-01

With the nuclear density distribution being simulated by the Boltzmann Uehling-Uhlenbeck equation and Vlasov equation with several rotational frequencies, the time evolution of the quadrupole moment of nucleus 86 Zr starting with superdeformed shape is studied. The contribution of two-body collisions and the effects of collective rotation to the shape evolution is investigated. The numerical results indicate that the two-body collisions play a role of damping on the evolution from a superdeformed shape to a normal deformed one in a case without rotation. In a case of rotation with lower frequency, the two-body collisions accelerate the evolution process. A new role of the collective rotation to enhance the nuclear fission is proposed. (author)

New results on order and spacing of levels for two- and three-body systems

International Nuclear Information System (INIS)

Grosse, H.; Martin, A.; Richard, J.M.; Taxil, P.

1987-01-01

The authors propose sufficient conditions on the potential binding a two-body system to compare; the energy of a state with angular momentum iota+1 to the average of the energies of the neighbouring states with angular momentum iota, the spacings of the successive iota = O excitations. Applications to quarkonium physics are given. The authors also find a condition giving the sign of the parameter Δ controlling the pattern of levels obtained by perturbing the lowest positive parity excitation of a three-body system bound by harmonic oscillator two body forces

plus two-body random matrix ensembles

Indian Academy of Sciences (India)

2015-02-03

Feb 3, 2015 ... Probability distribution (()) of the level spacing ratios has been introduced recently and is used to investigate many-body localization as well as to quantify the distance from integrability on finite size lattices. In this paper, we study the distribution of the ratio of consecutive level spacings using one-body ...

Investigations of the structure and electromagnetic interactions of few body systems. Annual progress report, 1 September 1982-31 August 1983

International Nuclear Information System (INIS)

Harper, E.P.; Lehman, D.R.; Prats, F.

1983-01-01

The George Washington University nuclear theory group proposes to conduct investigations of the structure and electromagnetic interactions of few-body systems. The structural properties of the very light nuclei are examined by developing theoretical models that begin from the basic interactions between the constituents and that are solved exactly (numerically), i.e., full three- or four-body dynamics. Such models are then used in an attempt to understand the details of the strong and electromagnetic interactions of the few-nucleon nuclei after the basic underlying reaction mechanisms are understood with simpler models. These efforts are becoming increasingly important with the advent of high duty cycle, high current electron accelerators from which valuable data will be forthcoming that should permit unraveling the structure and interactions of the very-light nuclei. Examples of specific work proposed are the following: 1) Set up the equations for the low-energy photodisintegration of 3 He and 3 H including final-state interactions and the E1 plus E2 operators; 2) Develop a unified picture of the p + d → 3 He + γ, p + d → 3 He + π 0 , p + d → 3 H + π + reactions at intermediate energies; 3) Calculate the elastic and inelastic (1 + →0 + ) form factors for 6 Li with three-body (αNN) wave functions; 4) Calculate static properties (RMS radius, magnetic moment, and quadrupole moment) of 6 Li with three-body wave functions; and 5) Develop the theory for the coincidence reactions 6 Li(p,2p)nα, 6 Li(e,e'p)nα, and 6 Li(e,e'd)α. It is anticipated that these efforts will expand the frontiers of our knowledge about few-body nuclei

A deeper look at two concepts of measuring gene-gene interactions: logistic regression and interaction information revisited.

Science.gov (United States)

Mielniczuk, Jan; Teisseyre, Paweł

2018-03-01

Detection of gene-gene interactions is one of the most important challenges in genome-wide case-control studies. Besides traditional logistic regression analysis, recently the entropy-based methods attracted a significant attention. Among entropy-based methods, interaction information is one of the most promising measures having many desirable properties. Although both logistic regression and interaction information have been used in several genome-wide association studies, the relationship between them has not been thoroughly investigated theoretically. The present paper attempts to fill this gap. We show that although certain connections between the two methods exist, in general they refer two different concepts of dependence and looking for interactions in those two senses leads to different approaches to interaction detection. We introduce ordering between interaction measures and specify conditions for independent and dependent genes under which interaction information is more discriminative measure than logistic regression. Moreover, we show that for so-called perfect distributions those measures are equivalent. The numerical experiments illustrate the theoretical findings indicating that interaction information and its modified version are more universal tools for detecting various types of interaction than logistic regression and linkage disequilibrium measures. © 2017 WILEY PERIODICALS, INC.

Three-body unitarity with isobars revisited

Energy Technology Data Exchange (ETDEWEB)

Mai, M.; Hu, B. [The George Washington University, Washington, DC (United States); Doering, M. [The George Washington University, Washington, DC (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Pilloni, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Szczepaniak, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Indiana University, Center for Exploration of Energy and Matter, Bloomington, IN (United States); Indiana University, Physics Department, Bloomington, IN (United States)

2017-09-15

The particle exchange model of hadron interactions can be used to describe three-body scattering under the isobar assumption. In this study we start from the 3 → 3 scattering amplitude for spinless particles, which contains an isobar-spectator scattering amplitude. Using a Bethe-Salpeter Ansatz for the latter, we derive a relativistic three-dimensional scattering equation that manifestly fulfills three-body unitarity and two-body unitarity for the sub-amplitudes. This property holds for energies above breakup and also in the presence of resonances in the sub-amplitudes. (orig.)

Relativistic Few-Body Hadronic Physics Calculations

Energy Technology Data Exchange (ETDEWEB)

Polyzou, Wayne [Univ. of Iowa, Iowa City, IA (United States)

2016-06-20

The goal of this research proposal was to use ``few-body'' methods to understand the structure and reactions of systems of interacting hadrons (neutrons, protons, mesons, quarks) over a broad range of energy scales. Realistic mathematical models of few-hadron systems have the advantage that they are sufficiently simple that they can be solved with mathematically controlled errors. These systems are also simple enough that it is possible to perform complete accurate experimental measurements on these systems. Comparison between theory and experiment puts strong constraints on the structure of the models. Even though these systems are ``simple'', both the experiments and computations push the limits of technology. The important property of ``few-body'' systems is that the ``cluster property'' implies that the interactions that appear in few-body systems are identical to the interactions that appear in complicated many-body systems. Of particular interest are models that correctly describe physics at distance scales that are sensitive to the internal structure of the individual nucleons. The Heisenberg uncertainty principle implies that in order to be sensitive to physics on distance scales that are a fraction of the proton or neutron radius, a relativistic treatment of quantum mechanics is necessary. The research supported by this grant involved 30 years of effort devoted to studying all aspects of interacting two and three-body systems. Realistic interactions were used to compute bound states of two- and three-nucleon, and two- and three-quark systems. Scattering observables for these systems were computed for a broad range of energies - from zero energy scattering to few GeV scattering, where experimental evidence of sub-nucleon degrees of freedom is beginning to appear. Benchmark calculations were produced, which when compared with calculations of other groups provided an essential check on these complicated calculations. In

New techniques for experimental generation of two-dimensional blade-vortex interaction at low Reynolds numbers

Science.gov (United States)

Booth, E., Jr.; Yu, J. C.

1986-01-01

An experimental investigation of two dimensional blade vortex interaction was held at NASA Langley Research Center. The first phase was a flow visualization study to document the approach process of a two dimensional vortex as it encountered a loaded blade model. To accomplish the flow visualization study, a method for generating two dimensional vortex filaments was required. The numerical study used to define a new vortex generation process and the use of this process in the flow visualization study were documented. Additionally, photographic techniques and data analysis methods used in the flow visualization study are examined.

Repulsively interacting fermions in a two-dimensional deformed trap with spin-orbit coupling

DEFF Research Database (Denmark)

Marchukov, O. V.; Fedorov, D. V.; Jensen, A. S.

2015-01-01

We investigate a two-dimensional system of fermions with two internal (spin) degrees of freedom. It is confined by a deformed harmonic trap and subject to a Zeeman field, Rashba or Dresselhaus one-body spin-orbit couplings and two-body short range repulsion. We obtain self-consistent mean-field $N...

Dressed molecules in resonantly interacting ultracold atomic Fermi gases

NARCIS (Netherlands)

Falco, G.M.; Stoof, H.T.C.

2007-01-01

We present a detailed analysis of the two-channel atom-molecule effective Hamiltonian for an ultracold two-component homogeneous Fermi gas interacting near a Feshbach resonance. We particularly focus on the two-body and many-body properties of the dressed molecules in such a gas. An exact result

Dynamics of vortex interactions in two-dimensional flows

DEFF Research Database (Denmark)

Juul Rasmussen, J.; Nielsen, A.H.; Naulin, V.

2002-01-01

The dynamics and interaction of like-signed vortex structures in two dimensional flows are investigated by means of direct numerical solutions of the two-dimensional Navier-Stokes equations. Two vortices with distributed vorticity merge when their distance relative to their radius, d/R-0l. is below...... a critical value, a(c). Using the Weiss-field, a(c) is estimated for vortex patches. Introducing an effective radius for vortices with distributed vorticity, we find that 3.3 ... is effectively producing small scale structures and the relation to the enstrophy "cascade" in developed 2D turbulence is discussed. The influence of finite viscosity on the merging is also investigated. Additionally, we examine vortex interactions on a finite domain, and discuss the results in connection...

Social signal processing for studying parent-infant interaction

Directory of Open Access Journals (Sweden)

Marie eAvril

2014-12-01

Full Text Available Studying early interactions is a core issue of infant development and psychopathology. Automatic social signal processing theoretically offers the possibility to extract and analyse communication by taking an integrative perspective, considering the multimodal nature and dynamics of behaviours (including synchrony. This paper proposes an explorative method to acquire and extract relevant social signals from a naturalistic early parent-infant interaction. An experimental setup is proposed based on both clinical and technical requirements. We extracted various cues from body postures and speech productions of partners using the IMI2S (Interaction, Multimodal Integration, and Social Signal Framework. Preliminary clinical and computational results are reported for two dyads (one pathological in a situation of severe emotional neglect and one normal control as an illustration of our cross-disciplinary protocol. The results from both clinical and computational analyses highlight similar differences: the pathological dyad shows dyssynchronic interaction led by the infant whereas the control dyad shows synchronic interaction and a smooth interactive dialog. The results suggest that the current method might be promising for future studies.

Neutral weak-current two-body contributions in inclusive scattering from {sup 12}C

Energy Technology Data Exchange (ETDEWEB)

Lovato, Alessandro [ANL; Gandolfi, Stefano [LANL; Carlson, Joseph [LANL; Pieper, S. C. [ANL; Schiavilla, Rocco [JLAB, ODU

2014-05-01

An {\\it ab initio} calculation of the sum rules of the neutral weak response functions in $^{12}$C is reported, based on a realistic Hamiltonian, including two- and three-nucleon potentials, and on realistic currents, consisting of one- and two-body terms. We find that the sum rules of the response functions associated with the longitudinal and transverse components of the (space-like) neutral current are largest and that a significant portion ($\\simeq 30$\\%) of the calculated strength is due to two-body terms. This fact may have implications for the MiniBooNE and other neutrino quasi-elastic scattering data on nuclei.

Investigations of the structure and electromagnetic interactions of few-body systems. Progress report, 1 January 1980-1 October 1980

Energy Technology Data Exchange (ETDEWEB)

Harper, E P; Lehman, D R; Prats, F

1980-11-07

Considerable progress has been made on the long-range problems described in the original proposal document (1 February 1979 to 31 January 1980) and on the shorter-range problems described in the last renewal proposal (1 February 1980 to 31 January 1981). This progress concerns few-body structure problems (e.g., the existence of isobar components in /sup 3/H, predictions of few-body-hypernuclei properties as a test of hyperon-nucleon interactions, investigation of the A = 6 ground states with exact three-body calculations, and the relation of triton D-state properties to the deuteron's D-state percentage) and electromagnetic properties and interactions of few-body nuclei (e.g., Coulomb effects in calculating and measuring asymptotic normalization constants, and ..gamma.. + /sup 3/He breakup reaction mechanisms at intermediate energies). Descriptions of the progress made indicate where each subject stands at present, and emphasize the significant results obtained. A publication list is attached.

Model calculations of doubly closed shell nuclei in the integral-differential equation approach describing the two body correlations

International Nuclear Information System (INIS)

Brizzi, R.; Fabre de la Ripelle, M.; Lassaut, M.

1999-01-01

The binding energies and root mean square radii obtained from the Integro-Differential Equation Approach (IDEA) and from the Weight Function Approximation (WFA) of the IDEA for an even number of bosons and for 12 C, 16 O and 40 Ca are compared to those recently obtained by the Variational Monte Carlo, Fermi Hypernetted Chain and Coupled Cluster expansion method with model potentials. The IDEA provides numbers very similar to those obtained by other methods although it takes only two-body correlations into account. The analytical expression of the wave function for the WFA is given for bosons in ground state when the interaction pair is outside the potential range. Due to its simple structure, the equations of the IDEA can easily be extended to realistic interaction for nuclei like it has already been done for the tri-nucleon and the 4 He. (authors)

Respiratory foreign bodies and Eikenella corrodens brain abscess in two children

International Nuclear Information System (INIS)

Sane, S.M.; Belani, K.K.; Faerber, E.N.

1999-01-01

We report the coexistence of aspirated foreign bodies and brain abscess in two boys. One child had aspirated a metallic needle, and in the other boy partially embedded sunflower seeds were found in the bronchial wall. Both patients had growth of Eikenella corrodens (oral gram-negative flora) from the abscess. Aspirated foreign body in the respiratory tract should be one of the diagnostic considerations if any of the normal oropharyngeal organisms such as E. corrodens is the causative organism of brain abscess. (orig.)

Entanglement properties between two atoms in the binomial optical field interacting with two entangled atoms

International Nuclear Information System (INIS)

Liu Tang-Kun; Zhang Kang-Long; Tao Yu; Shan Chuan-Jia; Liu Ji-Bing

2016-01-01

The temporal evolution of the degree of entanglement between two atoms in a system of the binomial optical field interacting with two arbitrary entangled atoms is investigated. The influence of the strength of the dipole–dipole interaction between two atoms, probabilities of the Bernoulli trial, and particle number of the binomial optical field on the temporal evolution of the atomic entanglement are discussed. The result shows that the two atoms are always in the entanglement state. Moreover, if and only if the two atoms are initially in the maximally entangled state, the entanglement evolution is not affected by the parameters, and the degree of entanglement is always kept as 1. (paper)

Interaction with glycosaminoglycans is required for cyclophilin B to trigger integrin-mediated adhesion of peripheral blood T lymphocytes to extracellular matrix

OpenAIRE

Allain, Fabrice; Vanpouille, Christophe; Carpentier, Mathieu; Slomianny, Marie-Christine; Durieux, Sandrine; Spik, Geneviève

2002-01-01

Cyclophilins A and B (CyPA and CyPB) are cyclosporin A-binding proteins that are involved in inflammatory events. We have reported that CyPB interacts with two types of cell-surface-binding sites. The first site corresponds to a functional receptor and requires interaction with the central core of CyPB. This region is highly conserved in cyclophilins, suggesting that CyPA and CyPB might share biological activities mediated by interaction with this receptor. The second site is identified with ...

Effective field theory for NN interactions

International Nuclear Information System (INIS)

Tran Duy Khuong; Vo Hanh Phuc

2003-01-01

The effective field theory of NN interactions is formulated and the power counting appropriate to this case is reviewed. It is more subtle than in most effective field theories since in the limit that the S-wave NN scattering lengths go to infinity. It is governed by nontrivial fixed point. The leading two body terms in the effective field theory for nucleon self interactions are scale invariant and invariant under Wigner SU(4) spin-isospin symmetry in this limit. Higher body terms with no derivatives (i.e. three and four body terms) are automatically invariant under Wigner symmetry. (author)

N-Oxide-N-oxide interactions and Cl...Cl halogen bonds in pentachloropyridine N-oxide: the many-body approach to interactions in the crystal state.

Science.gov (United States)

Wzgarda-Raj, Kinga; Rybarczyk-Pirek, Agnieszka J; Wojtulewski, Sławomir; Palusiak, Marcin

2018-02-01

Pentachloropyridine N-oxide, C 5 Cl 5 NO, crystallizes in the monoclinic space group P2 1 /c. In the crystal structure, molecules are linked by C-Cl...Cl halogen bonds into infinite ribbons extending along the crystallographic [100] direction. These molecular aggregates are further stabilized by very short intermolecular N-oxide-N-oxide interactions into herringbone motifs. Computations based on quantum chemistry methods allowed for a more detailed description of the N-oxide-N-oxide interactions and Cl...Cl halogen bonds. For this purpose, Hirshfeld surface analysis and the many-body approach to interaction energy were applied.

A new approach using the Pierce two-node model for different body parts.

Science.gov (United States)

Foda, Ehab; Sirén, Kai

2011-07-01

This paper presents a new approach, in applying the Pierce two-node model, to predict local skin temperatures of individual body parts with good accuracy. In this study, local skin temperature measurements at 24 sites on the bodies of 11 human subjects were carried out in a controlled environment under three different indoor conditions (i.e. neutral, warm and cold). The neutral condition measurements were used to adjust the local skin set-points in the model for each body part. Additional modifications to the calculation algorithm were introduced corresponding to different body parts. The local core set-points were then calculated, using a line search method, as the input values that allow the model to predict the skin temperatures with maximum deviation of ±0.1°C for the neutral condition. The model predictability was verified for the other two indoor conditions, and the results show that the modified model predicts local skin temperatures with average deviation of ±0.3°C.

The gravitational interaction between N-body (star clusters) and hydrodynamic (ISM) codes in disk galaxy simulations

International Nuclear Information System (INIS)

Schroeder, M.C.; Comins, N.F.

1986-01-01

During the past twenty years, three approaches to numerical simulations of the evolution of galaxies have been developed. The first approach, N-body programs, models the motion of clusters of stars as point particles which interact via their gravitational potentials to determine the system dynamics. Some N-body codes model molecular clouds as colliding, inelastic particles. The second approach, hydrodynamic models of galactic dynamics, simulates the activity of the interstellar medium as a compressible gas. These models presently do not include stars, the effect of gravitational fields, or allow for stellar evolution and exchange of mass or angular momentum between stars and the interstellar medium. The third approach, stochastic star formation simulations of disk galaxies, allows for the interaction between stars and interstellar gas, but does not allow the star particles to move under the influence of gravity

Towards Efficient Wireless Body Area Network Using Two-Way Relay Cooperation.

Science.gov (United States)

Waheed, Maham; Ahmad, Rizwan; Ahmed, Waqas; Drieberg, Micheal; Alam, Muhammad Mahtab

2018-02-13

The fabrication of lightweight, ultra-thin, low power and intelligent body-borne sensors leads to novel advances in wireless body area networks (WBANs). Depending on the placement of the nodes, it is characterized as in/on body WBAN; thus, the channel is largely affected by body posture, clothing, muscle movement, body temperature and climatic conditions. The energy resources are limited and it is not feasible to replace the sensor's battery frequently. In order to keep the sensor in working condition, the channel resources should be reserved. The lifetime of the sensor is very crucial and it highly depends on transmission among sensor nodes and energy consumption. The reliability and energy efficiency in WBAN applications play a vital role. In this paper, the analytical expressions for energy efficiency (EE) and packet error rate (PER) are formulated for two-way relay cooperative communication. The results depict better reliability and efficiency compared to direct and one-way relay communication. The effective performance range of direct vs. cooperative communication is separated by a threshold distance. Based on EE calculations, an optimal packet size is observed that provides maximum efficiency over a certain link length. A smart and energy efficient system is articulated that utilizes all three communication modes, namely direct, one-way relay and two-way relay, as the direct link performs better for a certain range, but the cooperative communication gives better results for increased distance in terms of EE. The efficacy of the proposed hybrid scheme is also demonstrated over a practical quasi-static channel. Furthermore, link length extension and diversity is achieved by joint network-channel (JNC) coding the cooperative link.

Towards Efficient Wireless Body Area Network Using Two-Way Relay Cooperation

Directory of Open Access Journals (Sweden)

Maham Waheed

2018-02-01

Full Text Available The fabrication of lightweight, ultra-thin, low power and intelligent body-borne sensors leads to novel advances in wireless body area networks (WBANs. Depending on the placement of the nodes, it is characterized as in/on body WBAN; thus, the channel is largely affected by body posture, clothing, muscle movement, body temperature and climatic conditions. The energy resources are limited and it is not feasible to replace the sensor’s battery frequently. In order to keep the sensor in working condition, the channel resources should be reserved. The lifetime of the sensor is very crucial and it highly depends on transmission among sensor nodes and energy consumption. The reliability and energy efficiency in WBAN applications play a vital role. In this paper, the analytical expressions for energy efficiency (EE and packet error rate (PER are formulated for two-way relay cooperative communication. The results depict better reliability and efficiency compared to direct and one-way relay communication. The effective performance range of direct vs. cooperative communication is separated by a threshold distance. Based on EE calculations, an optimal packet size is observed that provides maximum efficiency over a certain link length. A smart and energy efficient system is articulated that utilizes all three communication modes, namely direct, one-way relay and two-way relay, as the direct link performs better for a certain range, but the cooperative communication gives better results for increased distance in terms of EE. The efficacy of the proposed hybrid scheme is also demonstrated over a practical quasi-static channel. Furthermore, link length extension and diversity is achieved by joint network-channel (JNC coding the cooperative link.

Two distinct modes of RecA action are required for DNA polymerase V-catalyzed translesion synthesis.

Science.gov (United States)

Pham, Phuong; Seitz, Erica M; Saveliev, Sergei; Shen, Xuan; Woodgate, Roger; Cox, Michael M; Goodman, Myron F

2002-08-20

SOS mutagenesis in Escherichia coli requires DNA polymerase V (pol V) and RecA protein to copy damaged DNA templates. Here we show that two distinct biochemical modes for RecA protein are necessary for pol V-catalyzed translesion synthesis. One RecA mode is characterized by a strong stimulation in nucleotide incorporation either directly opposite a lesion or at undamaged template sites, but by the absence of lesion bypass. A separate RecA mode is necessary for translesion synthesis. The RecA1730 mutant protein, which was identified on the basis of its inability to promote pol V (UmuD'(2)C)-dependent UV-mutagenesis, appears proficient for the first mode of RecA action but is deficient in the second mode. Data are presented suggesting that the two RecA modes are "nonfilamentous". That is, contrary to current models for SOS mutagenesis, formation of a RecA nucleoprotein filament may not be required for copying damaged DNA templates. Instead, SOS mutagenesis occurs when pol V interacts with two RecA molecules, first at a 3' primer end, upstream of a template lesion, where RecA mode 1 stimulates pol V activity, and subsequently at a site immediately downstream of the lesion, where RecA mode 2 cocatalyzes lesion bypass. We posit that in vivo assembly of a RecA nucleoprotein filament may be required principally to target pol V to a site of DNA damage and to stabilize the pol V-RecA interaction at the lesion. However, it is only a RecA molecule located at the 3' filament tip, proximal to a damaged template base, that is directly responsible for translesion synthesis.

Action during body perception: processing time affects self-other correspondences.

Science.gov (United States)

Reed, Catherine L; McGoldrick, John E

2007-01-01

The accurate perception of other people and their postures is essential for functioning in a social world. Our own bodies organize information from others to help us respond appropriately by creating self-other mappings between bodies. In this study, we investigated mechanisms involved in the processing of self-other correspondences. Reed and Farah (1995) showed that a multimodal, articulated body representation containing the spatial relations among parts of the human body was accessed by both viewing another's body and moving one's own. Use of one part of the body representation facilitated the perception of homologous areas of other people's bodies, suggesting that inputs from both the self and other activated the shared body representation. Here we investigated whether this self-other correspondence produced rapid facilitation or required additional processing time to resolve competing inputs for a shared body representation. Using a modified Reed and Farah dual-task paradigm, we found that processing time influenced body-position memory: an interaction between body-part moved and body-part attended revealed a relative facilitation effect at the 5 s ISI, but interference at the 2 s ISI. Our results suggest that effective visual-motor integration from the self and other requires time to activate shared portions of the spatial body representation.

What is an attractive body? Using an interactive 3D program to create the ideal body for you and your partner.

Directory of Open Access Journals (Sweden)

Kara L Crossley

Full Text Available What is the ideal body size and shape that we want for ourselves and our partners? What are the important physical features in this ideal? And do both genders agree on what is an attractive body? To answer these questions we used a 3D interactive software system which allows our participants to produce a photorealistic, virtual male or female body. Forty female and forty male heterosexual Caucasian observers (females mean age 19.10 years, s.d. 1.01; 40 males mean age 19.84, s.d. 1.66 set their own ideal size and shape, and the size and shape of their ideal partner using the DAZ studio image manipulation programme. In this programme the shape and size of a 3D body can be altered along 94 independent dimensions, allowing each participant to create the exact size and shape of the body they want. The volume (and thus the weight assuming a standard density and the circumference of the bust, waist and hips of these 3D models can then be measured. The ideal female body set by women (BMI = 18.9, WHR = 0.70, WCR = 0.67 was very similar to the ideal partner set by men, particularly in their BMI (BMI = 18.8, WHR = 0.73, WCR = 0.69. This was a lower BMI than the actual BMI of 39 of the 40 women. The ideal male body set by the men (BMI = 25.9, WHR = 0.87, WCR = 0.74 was very similar to the ideal partner set by the women (BMI = 24.5, WHR = 0.86, WCR = 0.77. This was a lower BMI than the actual BMI of roughly half of the men and a higher BMI than the other half. The results suggest a consistent preference for an ideal male and female body size and shape across both genders. The results also suggest that both BMI and torso shape are important components for the creation of the ideal body.

Acoustic interactions between inversion symmetric and asymmetric two-level systems

International Nuclear Information System (INIS)

Churkin, A; Schechter, M; Barash, D

2014-01-01

Amorphous solids, as well as many disordered lattices, display remarkable universality in their low temperature acoustic properties. This universality is attributed to the attenuation of phonons by tunneling two-level systems (TLSs), facilitated by the interaction of the TLSs with the phonon field. TLS-phonon interaction also mediates effective TLS–TLS interactions, which dictates the existence of a glassy phase and its low energy properties. Here we consider KBr:CN, the archetypal disordered lattice showing universality. We calculate numerically, using conjugate gradients method, the effective TLS–TLS interactions for inversion symmetric (CN flips) and asymmetric (CN rotations) TLSs, in the absence and presence of disorder, in two and three dimensions. The observed dependence of the magnitude and spatial power law of the interaction on TLS symmetry, and its change with disorder, characterizes TLS–TLS interactions in disordered lattices in both extreme and moderate dilutions. Our results are in good agreement with the two-TLS model, recently introduced to explain long-standing questions regarding the quantitative universality of phonon attenuation and the energy scale of ≈1–3 K below which universality is observed. (paper)

Neutrinos, Weak Interactions, and r-process Nucleosynthesis

International Nuclear Information System (INIS)

Balantekin, A B

2006-01-01

Two of the key issues in understanding the neutron-to-proton ratio in a corecollapse supernova are discussed. One of these is the behavior of the neutrino-nucleon cross sections as supernova energies. The other issue is the many-body properties of the neutrino gas near the core when both one- and two-body interaction terms are included

Ice-ocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers

Science.gov (United States)

Chauché, N.; Hubbard, A.; Gascard, J.-C.; Box, J. E.; Bates, R.; Koppes, M.; Sole, A.; Christoffersen, P.; Patton, H.

2014-08-01

Warm, subtropical-originating Atlantic water (AW) has been identified as a primary driver of mass loss across the marine sectors of the Greenland Ice Sheet (GrIS), yet the specific processes by which this water mass interacts with and erodes the calving front of tidewater glaciers is frequently modelled and much speculated upon but remains largely unobserved. We present a suite of fjord salinity, temperature, turbidity versus depth casts along with glacial runoff estimation from Rink and Store glaciers, two major marine outlets draining the western sector of the GrIS during 2009 and 2010. We characterise the main water bodies present and interpret their interaction with their respective calving fronts. We identify two distinct processes of ice-ocean interaction which have distinct spatial and temporal footprints: (1) homogenous free convective melting which occurs across the calving front where AW is in direct contact with the ice mass, and (2) localised upwelling-driven melt by turbulent subglacial runoff mixing with fjord water which occurs at distinct injection points across the calving front. Throughout the study, AW at 2.8 ± 0.2 °C was consistently observed in contact with both glaciers below 450 m depth, yielding homogenous, free convective submarine melting up to ~200 m depth. Above this bottom layer, multiple interactions are identified, primarily controlled by the rate of subglacial fresh-water discharge which results in localised and discrete upwelling plumes. In the record melt year of 2010, the Store Glacier calving face was dominated by these runoff-driven plumes which led to a highly crenulated frontal geometry characterised by large embayments at the subglacial portals separated by headlands which are dominated by calving. Rink Glacier, which is significantly deeper than Store has a larger proportion of its submerged calving face exposed to AW, which results in a uniform, relatively flat overall frontal geometry.

Two-way text messaging: an interactive mobile learning environment in higher education

Directory of Open Access Journals (Sweden)

H.K. Salinda Premadasa

2016-11-01

Full Text Available Short messaging service (SMS is perhaps the most popular mobile technology prevalent among students in higher education due to its ubiquitous nature and the capability of two-way communication. However, a major limitation in two-way text messaging is sending back a part of received data with the reply message. This limitation results in users of a mobile learning environment being unable to reply back to the correct destination. This article presents a two-way text messaging system that can be integrated into a learning management system (LMS to provide an interactive learning experience to the user community. Initially, a database is integrated into the LMS that holds message information such as recipient's phone number, message body and user data header. A specific port associated with the SMS is used to conceal and exchange data of a particular course unit. Subsequently, software in the student's mobile device captures this message and sends back the reply message to the appropriate course unit allowing both teachers and students to view messages sent and replies received pertaining to a particular course. Results indicate the educational impact of the proposed system in improving the learning environment and benefits it offers to the community in a campus-wide implementation.

$V_{td}$ from Hadronic Two-Body $B$ Decays

OpenAIRE

Gronau, Michael; Rosner, Jonathan L.

1996-01-01

Certain hadronic two-body decays of $B$ mesons are dominated by penguin diagrams. The ratios of rates for several such decays, including $\\Gamma(B^0 \\to \\overline{K}^{*0} K^0)/\\Gamma(B^0 \\to \\phi K^0)$, $\\Gamma(B^0 \\to \\overline{K}^{*0} K^{*0})/\\Gamma(B^0 \\to \\phi K^{*0})$, $\\Gamma(B^+ \\to \\overline{K}^{*0} K^+)$ $/\\Gamma(B^+ \\to \\phi K^+)$, and $\\Gamma(B^+ \\to \\overline{K}^{*0} K^{*+})/\\Gamma(B^+ \\to \\phi K^{*+})$, can provide information on the ratio of Cabibbo-Kobayashi-Maskawa (CKM) eleme...

Big or fast: two strategies in the developmental control of body size

OpenAIRE

Nijhout, H. Frederik

2015-01-01

Adult body size is controlled by the mechanisms that stop growth when a species-characteristic size has been reached. The mechanisms by which size is sensed and by which this information is transduced to the growth regulating system are beginning to be understood in a few species of insects. Two rather different strategies for control have been discovered; one favors large body size and the other favors rapid development.

The use of many-body expansions and geometry optimizations in fragment-based methods.

Science.gov (United States)

Fedorov, Dmitri G; Asada, Naoya; Nakanishi, Isao; Kitaura, Kazuo

2014-09-16

Conspectus Chemists routinely work with complex molecular systems: solutions, biochemical molecules, and amorphous and composite materials provide some typical examples. The questions one often asks are what are the driving forces for a chemical phenomenon? How reasonable are our views of chemical systems in terms of subunits, such as functional groups and individual molecules? How can one quantify the difference in physicochemical properties of functional units found in a different chemical environment? Are various effects on functional units in molecular systems additive? Can they be represented by pairwise potentials? Are there effects that cannot be represented in a simple picture of pairwise interactions? How can we obtain quantitative values for these effects? Many of these questions can be formulated in the language of many-body effects. They quantify the properties of subunits (fragments), referred to as one-body properties, pairwise interactions (two-body properties), couplings of two-body interactions described by three-body properties, and so on. By introducing the notion of fragments in the framework of quantum chemistry, one obtains two immense benefits: (a) chemists can finally relate to quantum chemistry, which now speaks their language, by discussing chemically interesting subunits and their interactions and (b) calculations become much faster due to a reduced computational scaling. For instance, the somewhat academic sounding question of the importance of three-body effects in water clusters is actually another way of asking how two hydrogen bonds affect each other, when they involve three water molecules. One aspect of this is the many-body charge transfer (CT), because the charge transfers in the two hydrogen bonds are coupled to each other (not independent). In this work, we provide a generalized view on the use of many-body expansions in fragment-based methods, focusing on the general aspects of the property expansion and a contraction of a

Electromagnetic reactions of few-body systems with the Lorentz integral transform method

International Nuclear Information System (INIS)

Leidemann, W.

2007-01-01

Various electromagnetic few-body break-up reactions into the many-body continuum are calculated microscopically with the Lorentz integral transform (LIT) method. For three- and four-body nuclei the nuclear Hamiltonian includes two- and three-nucleon forces, while semirealistic interactions are used in case of six- and seven-body systems. Comparisons with experimental data are discussed. In addition various interesting aspects of the 4 He photodisintegration are studied: investigation of a tetrahedrical symmetry of 4 He and a test of non-local nuclear force models via the induced two-body currents

DISCO Interacting Protein 2 regulates axonal bifurcation and guidance of Drosophila mushroom body neurons.

Science.gov (United States)

Nitta, Yohei; Yamazaki, Daisuke; Sugie, Atsushi; Hiroi, Makoto; Tabata, Tetsuya

2017-01-15

Axonal branching is one of the key processes within the enormous complexity of the nervous system to enable a single neuron to send information to multiple targets. However, the molecular mechanisms that control branch formation are poorly understood. In particular, previous studies have rarely addressed the mechanisms underlying axonal bifurcation, in which axons form new branches via splitting of the growth cone. We demonstrate that DISCO Interacting Protein 2 (DIP2) is required for precise axonal bifurcation in Drosophila mushroom body (MB) neurons by suppressing ectopic bifurcation and regulating the guidance of sister axons. We also found that DIP2 localize to the plasma membrane. Domain function analysis revealed that the AMP-synthetase domains of DIP2 are essential for its function, which may involve exerting a catalytic activity that modifies fatty acids. Genetic analysis and subsequent biochemical analysis suggested that DIP2 is involved in the fatty acid metabolization of acyl-CoA. Taken together, our results reveal a function of DIP2 in the developing nervous system and provide a potential functional relationship between fatty acid metabolism and axon morphogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

Many-body Anderson localization of strongly interacting bosons in random lattices

International Nuclear Information System (INIS)

Katzer, Roman

2015-05-01

In the present work, we investigate the problem of many-body localization of strongly interacting bosons in random lattices within the disordered Bose-Hubbard model. This involves treating both the local Mott-Hubbard physics as well as the non-local quantum interference processes, which give rise to the phenomenon of Anderson localization, within the same theory. In order to determine the interaction induced transition to the Mott insulator phase, it is necessary to treat the local particle interaction exactly. Therefore, here we use a mean-field approach that approximates only the kinetic term of the Hamiltonian. This way, the full problem of interacting bosons on a random lattice is reduced to a local problem of a single site coupled to a particle bath, which has to be solved self-consistently. In accordance to previous works, we find that a finite disorder width leads to a reduced size of the Mott insulating regions. The transition from the superfluid phase to the Bose glass phase is driven by the non-local effect of Anderson localization. In order to describe this transition, one needs to work within a theory that is non-local as well. Therefore, here we introduce a new approach to the problem. Based on the results for the local excitation spectrum obtained within the mean-field theory, we reduce the full, interacting model to an effective, non-interacting model by applying a truncation scheme to the Hilbert space. Evaluating the long-ranged current density within this approximation, we identify the transition from the Bose glass to the superfluid phase with the Anderson transition of the effective model. Resolving this transition using the self-consistent theory of localization, we obtain the full phase diagram of the disordered Bose-Hubbard model in the regime of strong interaction and larger disorder. In accordance to the theorem of inclusions, we find that the Mott insulator and the superfluid phase are always separated by the compressible, but insulating

Synchronization of muscular oscillations between two subjects during isometric interaction

Directory of Open Access Journals (Sweden)

Laura V. Schaefer

2014-05-01

Full Text Available Muscles oscillate with a frequency around 10 Hz. But what happens with myofascial oscillations, if two neuromuscular systems interact? The purpose of this study was to examine this question, initially, on the basis of a case study. Oscillations of the triceps brachii muscles of two subjects were determined through mechanomyography (MMG during isometric interaction. The MMG-signals were analyzed concerning the interaction of the two subjects with algorithms of nonlinear dynamics. In this case study it could be shown, that the muscles of both neuromuscular systems also oscillate with the known frequency (here 12 Hz during interaction. Furthermore, both subjects were able to adapt their oscillations against each other. This adjustment induced a significant ( < .05 coherent behavior, which was characterized by a phase shifting of approximately 90°. The authors draw the conclusion, that the complementary neuromuscular partners potentially have the ability of mutual synchronization.

Three-body recombination of cold fermionic atoms

International Nuclear Information System (INIS)

Suno, H; Esry, B D; Greene, Chris H

2003-01-01

Recombination of identical, spin-polarized fermions in cold three-body collisions is investigated. We parametrize the mechanisms for recombination in terms of the 'scattering volume' V p and another length scale r 0 . Model two-body interactions were used within the framework of the adiabatic hyperspherical representation. We examine the recombination rate K 3 as a function of the collision energy E for various values of V p . Not only do we consider the dominant J Π = 1 + case, but also the next-leading order contributions from J Π = 1 - and 3 - . We discuss the behaviour near a two-body resonance and the expected universality of fermionic recombination. Comparisons with boson recombination are considered in detail

Situated meaning-making of the human body: a study of elementary school children's reasons in two different activities

Science.gov (United States)

Lundin, Mattias; Jakobson, Britt

2014-03-01

In this text we compare children's expressions in drawings to their statements during interviews, for the purpose of understanding how different situations afford children to make meaning. In specific we study how two different activities interact and afford children to make meaning differently about the human body. The analytic attention is drawn to the meaning-making the children made as they in pairs were asked to explain the body drawings that they did prior to the interviews. Meaning-making was studied by using a practical epistemology analysis, an analysis facilitating understanding of how relations are established in a developing conversation, and more generally providing understanding from a child perspective. The results indicate that several reasons are at hand for children in the two different situations; namely, social, artistic, practical, empirical and memory reasons are identified. Social reasons refer to statements belonging to the social context and items that were described as inappropriate to express. Artistic reasons were interpreted from aesthetic judgements, referring to the artistic quality of the drawing. Practical reasons were given in situations where children expressed, for example, that the space limited their opportunities to draw. Empirical reasons are built on children's statements referring to picture items that are identified by pointing or touching their own body. Memory reasons are involved in all the situations where children explained items were previously omitted, because the body part had been temporarily forgotten. Furthermore, we suggest that children interpret situational aspects and make judgements concerning the relevance of their different reasons. By these means we hope to facilitate children's understanding of interview questions and also to improve researchers' understanding of children's ability to grasp relevant details prior to their response (or participation).

Kinesthetic Interaction

DEFF Research Database (Denmark)

Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

2008-01-01

Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... practical examples of designing for bodily potential. This paper presents Kinesthetic Interaction as a unifying concept for describing the body in motion as a foundation for designing interactive systems. Based on the theoretical foundation for Kinesthetic Interaction, a conceptual framework is introduced...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is a tool...

Interpersonal similarity between body movements in face-to-face communication in daily life.

Science.gov (United States)

Higo, Naoki; Ogawa, Ken-ichiro; Minemura, Juichi; Xu, Bujie; Nozawa, Takayuki; Ogata, Taiki; Ara, Koji; Yano, Kazuo; Miyake, Yoshihiro

2014-01-01

Individuals are embedded in social networks in which they communicate with others in their daily lives. Because smooth face-to-face communication is the key to maintaining these networks, measuring the smoothness of such communication is an important issue. One indicator of smoothness is the similarity of the body movements of the two individuals concerned. A typical example noted in experimental environments is the interpersonal synchronization of body movements such as nods and gestures during smooth face-to-face communication. It should therefore be possible to estimate quantitatively the smoothness of face-to-face communication in social networks through measurement of the synchronization of body movements. However, this is difficult because social networks, which differ from disciplined experimental environments, are open environments for the face-to-face communication between two individuals. In such open environments, their body movements become complicated by various external factors and may follow unstable and nonuniform patterns. Nevertheless, we consider there to be some interaction during face-to-face communication that leads to the interpersonal synchronization of body movements, which can be seen through the interpersonal similarity of body movements. The present study aims to clarify such interaction in terms of body movements during daily face-to-face communication in real organizations of more than 100 people. We analyzed data on the frequency of body movement for each individual during face-to-face communication, as measured by a wearable sensor, and evaluated the degree of interpersonal similarity of body movements between two individuals as their frequency difference. Furthermore, we generated uncorrelated data by resampling the data gathered and compared these two data sets statistically to distinguish the effects of actual face-to-face communication from those of the activities accompanying the communication. Our results confirm an

Interpersonal similarity between body movements in face-to-face communication in daily life.

Directory of Open Access Journals (Sweden)

Naoki Higo

Full Text Available Individuals are embedded in social networks in which they communicate with others in their daily lives. Because smooth face-to-face communication is the key to maintaining these networks, measuring the smoothness of such communication is an important issue. One indicator of smoothness is the similarity of the body movements of the two individuals concerned. A typical example noted in experimental environments is the interpersonal synchronization of body movements such as nods and gestures during smooth face-to-face communication. It should therefore be possible to estimate quantitatively the smoothness of face-to-face communication in social networks through measurement of the synchronization of body movements. However, this is difficult because social networks, which differ from disciplined experimental environments, are open environments for the face-to-face communication between two individuals. In such open environments, their body movements become complicated by various external factors and may follow unstable and nonuniform patterns. Nevertheless, we consider there to be some interaction during face-to-face communication that leads to the interpersonal synchronization of body movements, which can be seen through the interpersonal similarity of body movements. The present study aims to clarify such interaction in terms of body movements during daily face-to-face communication in real organizations of more than 100 people. We analyzed data on the frequency of body movement for each individual during face-to-face communication, as measured by a wearable sensor, and evaluated the degree of interpersonal similarity of body movements between two individuals as their frequency difference. Furthermore, we generated uncorrelated data by resampling the data gathered and compared these two data sets statistically to distinguish the effects of actual face-to-face communication from those of the activities accompanying the communication. Our results

Depletion interactions in two-dimensional colloid-polymer mixtures: molecular dynamics simulations

International Nuclear Information System (INIS)

Kim, Soon-Chul; Seong, Baek-Seok; Suh, Soong-Hyuck

2009-01-01

The depletion interactions acting between two hard colloids immersed in a bath of polymers, in which the interaction potentials include the soft repulsion/attraction, are extensively studied by using the molecular dynamics simulations. The collision frequencies and collision angle distributions for both incidental and reflection conditions are computed to study the dynamic properties of the colloidal mixtures. The depletion effect induced by the polymer-polymer and colloid-polymer interactions are investigated as well as the size ratio of the colloid and polymer. The simulated results show that the strong depletion interaction between two hard colloids appears for the highly asymmetric hard-disc mixtures. The attractive depletion force at contact becomes deeper and the repulsive barrier becomes wider as the asymmetry in size ratio increases. The strong polymer-polymer attraction leads to the purely attractive depletion interaction between two hard colloids, whereas the purely repulsive depletion interaction is induced by the strong colloid-polymer attraction.

Many body quantum physics at the condensed matter

International Nuclear Information System (INIS)

Llano, M. de

1981-01-01

The non-relativistic, continuous (as opposed to spin) many-body problem as it relates to condensed matter at absolute zero temperature is reviewed in simple, non-technical terms, mainly from the standpoint of infinite order perturbation theory, for physical systems where all the particles have the same mass but which otherwise interact with arbitrary short- or long-ranged two-body forces. (author)

Two maternal origins of Chinese domestic light-body type goose | Li ...

African Journals Online (AJOL)

Two maternal origins of Chinese domestic light-body type goose. ... The 521 bp control region (D-loop) of mitochondrial DNA from 13 lightbody type breeds ... the value within populations and all the breeds did not exist population expansion.

Searches for two-body charmless baryonic $B^0$ decays at LHCb

CERN Document Server

AUTHOR|(CDS)2083570; Eklund, Lars

2016-09-26

The results of two separate searches for the rare two-body charmless baryonic decays B0 -> p pbar and B0s -> p pbar at the LHCb experiment are reported in this thesis. The first analysis uses a data sample, corresponding to an integrated luminosity of 0.9 fb^-1, of proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 7 TeV. An excess of B0 -> p pbar candidates with respect to background expectations is seen with a statistical significance of 3.3 standard deviations. This constitutes the first evidence for a two-body charmless baryonic B0 decay. No significant B0s -> p pbar signal was observed. However, a small excess of B0s -> p pbar events allowed the extraction of two sided confidence level intervals for the B0s -> p pbar branching fraction using the Feldman-Cousins frequentist method. This improved the upper limit on the B0s -> p pbar branching fraction by three orders of magnitude over previous bounds. The 68.3% confidence level intervals on the branching fractions w...

A new separable expansion for the two-body problem

International Nuclear Information System (INIS)

Haberzettl, H.

1988-07-01

We derive a new separable expansion of the two-body T matrix which represents the T matrix as a series of diagonal separable terms. The representation is exact half-on-shell at all energies even when truncated to one single term; moreover, the truncated expansion satisfies the full off-shell unitarity relation. The approach does not take recourse to some complete set of functions but rather uses properties of the Lippmann-Schwinger equation itself to arrive at the expansion. It is based on the W-matrix representation of the two-body T matrix introduced by Bartnik, Haberzettl, and Sandhas. That representation provides a splitting of the T matrix in one single separable term which contains all bound state poles and scatttering cuts and in a nonsingular, real remainder which vanishes half-on-shell. The method presented here yields a separable expansion of this remainder in which all its properties are preserved term by term. Any given n-term approximation can easily be refined to an (n+1)-term expansion by simply adding a new term. At each stage the amount of additional numerical work is constant. The method is applicable to any kind of short range potential, local, nonlocal or energy dependent. (orig.)

Neutron-deuteron scattering calculations with W-matrix representation of the two-body input

International Nuclear Information System (INIS)

Bartnik, E.A.; Haberzettl, H.; Januschke, T.; Kerwath, U.; Sandhas, W.

1987-05-01

Employing the W-matrix representation of the partial-wave T matrix introduced by Bartnik, Haberzettl, and Sandhas, we show for the example of the Malfliet-Tjon potentials I and III that the single-term separable part of the W-matrix representation, when used as input in three-nucleon neutron-deuteron scattering calculations, is fully capable of reproducing the exact results obtained by Kloet and Tjon. This approximate two-body input not only satisfies the two-body off-shell unitarity relation but, moreover, it also contains a parameter which may be used in optimizing the three-body data. We present numerical evidence that there exists a variational (minimum) principle for the determination of the three-body binding energy which allows one to choose this parameter also in the absence of an exact reference calculation. Our results for neutron-deuteron scattering show that it is precisely this choice of the parameter which provides optimal scattering data. We conclude that the W-matrix approach, despite its simplicity, is a remarkably efficient tool for high-quality three-nucleon calculations. (orig.)

The Relationship between Body Movements and Qualities of Social Interaction between a Boy with Severe Developmental Disabilities and His Caregiver

Science.gov (United States)

Dammeyer, Jesper; Koppe, Simo

2013-01-01

Research in social interaction and nonverbal communication among individuals with severe developmental disabilities also includes the study of body movements. Advances in analytical technology give new possibilities for measuring body movements more accurately and reliably. One such advance is the Qualisys Motion Capture System (QMCS), which…

Quasi-four-body treatment of charge transfer in the collision of protons with atomic helium: I. Thomas related mechanisms

Science.gov (United States)

Safarzade, Zohre; Fathi, Reza; Shojaei Akbarabadi, Farideh; Bolorizadeh, Mohammad A.

2018-04-01

The scattering of a completely bare ion by atoms larger than hydrogen is at least a four-body interaction, and the charge transfer channel involves a two-step process. Amongst the two-step interactions of the high-velocity single charge transfer in an anion-atom collision, there is one whose amplitude demonstrates a peak in the angular distribution of the cross sections. This peak, the so-called Thomas peak, was predicted by Thomas in a two-step interaction, classically, which could also be described through three-body quantum mechanical models. This work discusses a four-body quantum treatment of the charge transfer in ion-atom collisions, where two-step interactions illustrating a Thomas peak are emphasized. In addition, the Pauli exclusion principle is taken into account for the initial and final states as well as the operators. It will be demonstrated that there is a momentum condition for each two-step interaction to occur in a single charge transfer channel, where new classical interactions lead to the Thomas mechanism.