bluuebunny/crossref_metadata_2025 huggingface dataset:
STATIONARITY-BREAKING BIFURCATIONS OF SOLITONS UNDER NONLINEAR DAMPING
Authors: GONZÁLEZ JORGE A. , CARBÓ JOSE R.
Published: November 2004

The existence and dynamics of solitons in general systems with nonlinear damping are investigated. The mechanism of a new bifurcation after which the soliton can no longer be in a stationary state is discussed. Some particular cases are studied in detail and exact solutions are presented. The possibility and importance of self-sustained solitons, solitonic limit cycles, and chaotic solitons in these systems are analyzed.
STABILITY OF THE ELECTRON AT A LOCALIZED STATE
Authors: ONOOCHIN V. V.
Published: November 2004

In the nonrelativistic limit, a single electron interacting with the electromagnetic field is considered. The energy functional of such a system is performed by means of the large polaron technique. One can conclude that the localized state of the electron in the electromagnetic field is stable.
SYMMETRY ANALYSIS AND SOME CLASSIFICATIONAL RESULTS ON THE RENORMALIZATION GROUP EQUATION
Authors: RUSTAMOV K. A.
Published: November 2004

Symmetry analysis of the renormalization group equation is fulfilled. As an example, physically applicable invariant solution is presented.
OPTICAL SHG EFFECT OF STOICHIOMETRIC Ba4Na2Nb10O30 (BNN), Gd-DOPED BNN, AND Nd-DOPED BNN
Authors: TSUKIOKA MASAYUKI , FUJIMOTO TETSUROU , TSUTSUMI SADAO
Published: November 2004

In order to investigate the doping effect of Ba 2 NaNb 5 O 15 by rare-earth ions, single crystals of stoichiometric BNN, Gd-doped BNN, and Nd-doped BNN were synthesized. The measurements were carried out for second harmonic generation (SHG), microscopic observation on {001}, and for dielectric property of these materials. The considerable effects by the doping were found for the SHG. The doping effect was investigated from the point of view of the theory of electro-optical and nonlinear optical effect on oxygen octahedral ferroelectrics, and from that of domain structure. Microscopic observation proved that the refractive index fluctuation causes several SHG phase matching conditions.
SHG CHARACTERISTIC OF Co-DOPED LiNbO3 SINGLE CRYSTAL
Authors: FUJIMOTO TETSUROU , WASEGURI TSUNEAKI , TSUTSUMI SADAO , TSUKIOKA MASAYUKI
Published: November 2004

In order to investigate the doping effect of LiNbO 3 by cobalt ion, LiNbO 3 single crystals doped with CoO, 0.02, 0.05, 0.2, and 1 mol% were synthesized. SHG characteristics were measured using CW YAG:Nd laser in the temperature range from 120 to 310 K. Optical absorption measurements were carried out in the wavelength between 300 and 1800 nm in the y direction. The largest conversion efficiency of SHG was observed in the 0.02 mol% doped crystal, which is due to harmonic effect. Microscopic observation of domain structure was also carried out. It is found that the domain layers of positive and negative orientation lie on top of another in the direction of the c axis, the thickness of which is of the order of microns. SHG intensity is discussed based on the relation between laser beam diameter and the thickness of domain layers.
DIFFUSION MECHANISMS DURING EPITAXY OF Cu/Cu(100) — AN ATOMIC VIEW
Authors: LIU CHUN-LI
Published: November 2004

Using an embedded atom method (EAM) potential, we have investigated the energetics of atomic diffusion processes of (1) single adatoms on a flat terrace and around steps of different orientations, and (2) small clusters of up to 5 atoms on a flat terrace during epitaxy of Cu/Cu(100). Exchange mechanism for adatoms to cross over descending steps and diffusion mechanism for adatoms to diffuse along step ledges were found to depend on step orientation. The simulation results show that the small clusters are quite mobile at room temperature, but dissociate at much higher temperature, as deduced from the low migration energies and high dissociation energies of the clusters calculated. Under certain conditions, tetramers are only the stable phase during epitaxy of Cu/Cu(100). The simulation results for single adatoms and small clusters obtained in this work are consistent with recent LEED experiments and can explain some experimental observations during epitaxy of Cu/Cu(100).
QUASIPERIODIC AND CHAOTIC BEHAVIOR ON ZAKHAROV EQUATIONS
Authors: ZHENG C. Y. , HE X. T. , TAN Y.
Published: November 2004

It is first shown from the modulation instability of the conserved Zakharov equations (ZE) that spatiotemporal chaos is formed in the different regions of the unstable wave numbers. We find that chaos sets in when two homoclinic structures are present and then many and continual homoclinic crossings occur throughout the time series. It is shown that the presence of a homoclinic structure is a potential source of both temporal chaos and spatial patterns.
MARGINAL FERMI LIQUID IN STRONGLY CORRELATED SPIN SYSTEMS
Authors: PROTOGENOV A. P. , RYNDYK D. A.
Published: November 2004

We consider the consequences of the separation of spin and charge degrees of freedom in 2 + 1 D strongly correlated spin systems. Self-consistent spin and charge motions induced by doping in sites of ground and dual lattices form such a spectrum of quasiparticles which together with the dispersionless character of the collective excitation spectrum and the chemical potential pinning in the band center yield the necessary behavior to support the theory of marginal Fermi liquid formulated by C. M. Varma et al. (Phys. Rev. Lett.63, 1996 (1989)).
DECAYING BEHAVIOR OF A SPIN-ALTERNATING [s, S] FERRIMAGNETIC ISING CHAIN WITH SINGLE-ION ANISOTROPY
Authors: KIM JONG-JAE
Published: November 2004

For a spin-alternating [Formula: see text] ferrimagnetic Ising chain with single-ion anisotropy, exact expressions of the wave-vector-dependent structure factor Γ(q) and the correlation length ξ are given by the transfer matrix method. Some unusual decaying behaviors of the chain, caused by the single-ion anisotropy, are explained in detail in the two representative cases of an integer spin S = 1 and a half-integer spin [Formula: see text]. Γ(q) shows a two-peaked structure with the absolute peak at q = π and the subpeak at q = 0, when the ferrimagnetic (FR) short-range order occurs at low T. In the case of S = 1, the limiting behaviors of ξ as T → 0 K are classified into three cases: diverging exponetially in the FR-phase region, vanishing exponentially in the partially-disordered(PD)-phase region, or converging towards a finite value at the FR–PD phase boundary. In the FR-phase region, the metamagnetic behavior is observed both in the S = 1 case and in the [Formula: see text] case, as magnetic field increases.
SQUEEZING AND SOME OTHER CHARACTERISTICS OF TIME-DEPENDENT HARMONIC OSCILLATOR WITH VARIABLE MASS
Authors: JOSHI A. , LAWANDE S. V.
Published: November 2004

In this paper we investigate the time evolution of a general time-dependent harmonic oscillator (TDHO) with variable mass using Feynman path integral approach. We explicitly evaluate the squeezing in the quadrature components of a general quantum TDHO with variable mass. This calculation is further elaborated for three particular cases of variable mass whose propagator can be written in a closed form. We also obtain an exact form of the time-evolution operator, the wave function, and the time-dependent coherent state for the TDHO. Our results clearly indicate that the time-dependent coherent state is equivalent to the squeezed coherent state.
CATION DISTRIBUTION OF LITHIUM–TITANIUM MIXED FERRITES
Authors: REDDY M. BHAGAVANTHA , REDDY V. DEVENDER , REDDY P. VENUGOPAL
Published: November 2004

Cation distribution of Li–Ti mixed ferrites was derived from Seebeck coefficient measurements. The distribution of titanium on octahedron sites is found to increase continuously while the concentration of Fe 3+ and Fe 2+ are found to decrease rapidly. The data is very much useful to interpret the electrical properties of these materials.
COULOMB CORRELATIONS AND INSTABILITY OF SPINLESS FERMION GAS IN 1D AND 2D
Authors: CHEN HUA , MATTIS DANIEL
Published: November 2004

We study the stability of the ordinary Landau Fermi liquid phase for interacting, spinless electrons. We require causality and demand that the Pauli principle be obeyed. We find a phase diagram determined by two parameters: the particle density and the interaction strength. We find that the homogeneous, constant density Fermi liquid phase of a spinless Fermion gas is never stable in 1D, but that it may have a restricted domain of stability in 2D.
RECURRENCE FORMULA FOR ELASTICITY OF GELS UNDER PRESSURE
Authors: SKAL ASYA S.
Published: November 2004

We considered polymeric materials like rubber and gels where the scalar term of elastic energy is dominant. In strained materials with scalar nature of forces, a recurrence formula for internal force density as a sequence of power of the Poisson coefficient is obtained: [Formula: see text], where ν(r) and Y(r) are local values of the Poisson and Young coefficients, Y1 is the Young coefficient at the boundary of the sample, and ey and ez are unit vectors perpendicular to the external pressure Px. This formula gives contributions to all orders of the Poisson coefficient to the internal force density.
OPTIMIZING THE RVB STATE ON A TRIANGULAR LATTICE: PRESENCE OF THE LONG RANGE ORDER
Authors: CHEN YONG-CONG
Published: November 2004

We present a Schwinger boson approach for the RVB state of the spin-1/2 Heisenberg antiferromagnet on a triangular lattice. It is shown that a Gutzwiller projection of the mean field state that includes both antiferromagnetic and ferromagnetic decouplings leads to optimizing the RVB pair amplitudes within a self-consistent approximation. The resulting state yields, by Monte Carlo simulations, energies and spin-spin correlations in excellent agreement with the exact diagonalization result on finite lattices (up to 36 sites). We conclude that the optimized RVB wave function possesses a long range three-sublattice order.
JAHN-TELLER EFFECT OF MOLECULAR COMPLEXES IN LIQUID SOLUTIONS
Authors: HALLEY J.W. , WANG X.R.
Published: November 2004

We review recent work clarifying the sense in which the Jahn-Teller effect can exist in a molecular complex in liquid solution. We review the molecular dynamics methods for modeling such liquid systems using the cupric ion in aqueous solution as an example. We review the experimental evidence for the Jahn-Teller effect in liquids, emphasizing the importance of taking the time scale of the measurement into account. Finally we discuss the role of quantum coherence and the Berry phase in the Jahn-Teller effect.
FIRST ORDER PHASE TRANSITIONS AND PHASE DIAGRAMS OF SYSTEMS WITH A TWO-COMPONENT ORDER PARAMETER
Authors: BLAGOEVA EVGENIA J.
Published: November 2004

A complete mean field analysis of the sixth order Landau free energy for a two-dimensional order parameter is presented. Special attention is paid to its application to first order phase transitions. The phase diagram for all the allowed values of the expansion coefficients is constructed and the specific effects arising from the internal symmetry of the order parameter are emphasized.
DIPOLE-DIPOLE INTERACTION IN A SUPERCONDUCTOR
Authors: YANG Z.J.
Published: November 2004

Based on the London theory and the Pippard theory of superconductivity, we have calculated the magnetic induction distribution from a magnetic dipole located in a superconductor. The results have been used to evaluate the interaction energy between two magnetic dipoles located in the superconductor. The relevant applications of these calculations have been discussed briefly.
ON PHASE TRANSITIONS ON BETHE LATTICES
Authors: BURIONI RAFFAELLA , CASSI DAVIDE
Published: November 2004

Starting from some recent rigorous results about correlation functions of statistical model on tree structures, we analyze the nature of phase transitions occurring on Bethe lattices, showing the lack of long range order and the purely geometrical origin of the thermodynamic singularities. This approach gives a very simple formula for the critical temperature for any model with compact symmetry group and immediately leads to the value 1 for the critical exponent γ. The “geometrical” critical behavior only partially coincides with the mean field solution and violates the usual scaling relations.
ON THE QUANTUM NOISE REDUCTION OF A LASER-COOLED ION COUPLED TO A SOURCE OSCILLATOR
Authors: BASEIA B. , DANTAS CÉLIA M.A. , BAGNATO V.S.
Published: November 2004

In recent literature the treatment of the system constituted by a trapped laser-cooled ion coupled to the modes of a source oscillator is presented. Among several effects presented in this system, the transference of squeezing from the source oscillator to the cooled ion is investigated. In this paper we present an alternative and more elaborate approach for this problem considering mainly the generation and transference of squeezing in this coupled system. We find exact expression for the variances of the involved quadratures. Variations observed due to the change of the involved parameters are also discussed.
NUMERICAL SIMULATION OF POLYMER CRYSTALLIZATION
Authors: ANDREUCCI DANIELE , FASANO ANTONIO , PRIMICERIO MARIO , PAOLINI MAURIZIO , VERDI CLAUDIO
Published: November 2004

We consider a mathematical model for solidification of semicrystalline polymers, describing the evolution of temperature, crystalline volume fraction, number and average size of crystals. In turn, the model couples a suitable kinetics of nonisothermal crystallization, taking into account both formation and growth of nuclei, with the thermal energy balance equation. We also present a model of secondary crystallization. The numerical approximation is performed by semiexplicit finite differences in time and finite elements in space. The fully discrete scheme amounts to solve, at any time step, a symmetric positive definite linear system preceded by an elementwise explicit computation. The computed numerical crystal structures match qualitatively the experimental ones.
THE CHILD-LANGMUIR REGIME FOR ELECTRON TRANSPORT IN A PLASMA INCLUDING A BACKGROUND OF POSITIVE IONS
Authors: ABDALLAH NAOUFEL BEN
Published: November 2004

We consider the Child-Langmuir asymptotics11,5 of a monodimensional electron beam flowing through a background of positve ions of constant density nD. We extend the results valid for electron beams in the vacuum11,5 to the case of small nD’s. Large nD’s strongly modify the phase portrait of the characteristics of the Vlasov-Poisson equation and yield a different result.
CONVERGENCE ANALYSIS OF BERGAN’S ENERGY-ORTHOGONAL PLATE ELEMENT
Authors: SHI ZHONG-CI , CHEN SHAO-CHUN , ZHANG FEI
Published: November 2004

This paper gives a mathematical analysis of an energy-orthogonal free formulation plate element proposed by Bergan et al. It is shown that the new element is equivalent to a nonconforming element using a specific interpolation form of its shape function. The convergence property is analyzed and the error estimates for both moments and rotations are derived. Two improvement variants are suggested, which reduce the computational costs but improve the accuracy of error estimates.
MODEL KINETIC EQUATION FOR THE DISTRIBUTION OF DISCRETIZED INTERNAL ENERGY
Authors: NANBU K.
Published: November 2004

Kinetic equation for discretized internal energy is obtained by using the idea underlying the discrete-velocity kinetic theory. The equation satisfies the Boltzmann H-theorem. The solution of this equation in equilibrium is the Boltzmann distribution. The second moment of distribution shows an exponential relaxation.
EXACT (1+1)-DIMENSIONAL SOLUTIONS TO A DISCRETE VELOCITY MODEL FOR COAGULATION-FRAGMENTATION
Authors: IKLÉ M.
Published: November 2004

A family of discrete velocity models is proposed for the study of particle coagulation and fragmentation in gases. Patterned after the Broadwell model, the models allow inelastic collisions to occur, as well as elastic collisions. The models generate systems of highly coupled semilinear hyperbolic equations which approximate the Boltzmann equation. With the aid of the powerful computer algebra systems Mathematica and Maple, we find an exact four-parameter solution to the simplest model.
FROM VACUUM IN AN INFLATIONARY UNIVERSE TO FLUCTUATIONS IN THE MICROWAVE BACKGROUND: THE THREAD OF THE ARGUMENT
Authors: DERUELLE NATHALIE , LANGLOIS DAVID , POLARSKI DAVID
Published: November 2004

We sketch the logics of the argument which claims that the temperature fluctuations in the microwave background radiation, observed by the COBE satellite, have originated from quantum vacuum fluctuations in an early, inflationary phase of the evolution of the universe.
LORENTZIAN MANIFOLDS ADMITTING ISOTROPIC HYPERSURFACES SOLUTIONS OF EINSTEIN’S FIELD EQUATIONS
Authors: BURDET GUY , PAPACOSTAS TAXIARCHIS , PERRIN MARTINE
Published: November 2004

All spaces solutions of Einstein’s field equations, admitting an isotropic (null) hypersurface (hereafter referred under the acronymus “ishyps”) are determined in a geometric way. We consider in more details two sub-cases, the generalized Robinson-Bertotti, and the pp-waves spaces.
QUANTUM MECHANICAL COMPOSITION LAWS IN REPARAMETERIZATION INVARIANT SYSTEMS
Authors: HALLIWELL J.J. , ORTIZ M.E.
Published: November 2004

This paper gives a brief description of the derivation of a composition law for the propagator of a relativistic particle, in a sum over histories quantization. The extension of this derivation to the problem of finding a composition law for quantum cosmology is also discussed.
PT VIOLATION AND ORIENTABILITY IN THE EARLY UNIVERSE
Authors: MAGNON ANNE
Published: November 2004

We recall that the “Sagnac Effect” can be viewed as a clock converting rotation (torsion) into a lapse of time. It is shown that the two available helicities can be used to show that PT invariance can be experimentally confirmed within the framework of General Relativity. These clocks are rather similar to those proposed by de Broglie (the particle-clocks) to convert (right or left) rotation into a quantum of energy.

The Quantum analogue of this PT invariance is analyzed for zero rest-mass fields and related Mass and Spin Casimir operators.

We suggest that Quantum PT invariance could have been violated in the monopole phase, due to mixing of homotopy classes of the Lorentz Lie Group along a spacetime track, appearance of superselected Mass and Spin Casimir operators, and spontaneous breaking of their proportionality.

We suggest that this could be viewed as an evidence of the asymmetric flow of time, (arrow of time) in the Early Universe. Existence (non existence) of spinor structure and orientability of space, is discussed.
ANALYTIC SOLUTIONS FOR COSMOLOGICAL PERTURBATIONS IN MULTI-DIMENSIONAL SPACE-TIME
Authors: SCHWARZ DOMINIK J.
Published: November 2004

We obtain analytic solutions for the density contrast and the anisotropic pressure in a multi-dimensional FRW cosmology with collisionless, massless matter. These are compared with perturbations of a perfect fluid universe. To describe the metric perturbations we use manifest gauge invariant metric potentials. The matter perturbations are calculated by means of (automatically gauge invariant) finite temperature field theory, instead of kinetic theory.
COSMOLOGICAL SOLUTIONS IN 2D POINCARÉ GRAVITY
Authors: SOLODUKHIN S.N.
Published: November 2004

The 2D model of gravity with zweibeins ea and the Lorentz connection one-form [Formula: see text] as independent gravitational variables is considered. The solutions of classical equations of motion which can be interpreted as cosmological ones are studied.
A UNIFIED GAUGE FIELD LAGRANGIAN FOR ELECTROWEAK STRONG AND GRAVITATIONAL INTERACTION
Authors: VERWIMP THEO
Published: November 2004

Gravity can be descibed as a gauge field theory where connection and curvature are so(2,3)-valued. In the standard gauge field theory for strong and electroweak interaction corresponding quantities take their value in the su(3)⊕su(2)⊕u(1) algebra. Therefore, unification of gravity with the other fundamental interactions is obtained by using the non-compact simple real Lie algebra so*(14)⊃so(2,3)⊕su(3)⊕su(2)⊕u(1) as a unifying algebra. The so*(14) gauge field defined by a connection one-form on the SO*(14) principal fiber bundle unifies the fundamental interactions in particle physics, gravity included. The unified gauge field Lagrangian is defined by the Yang-Mills Weil form on the SO*(14) principal bundle.
CUSP ANNIHILATION ON ORDINARY COSMIC STRINGS
Authors: MOHAZZAB M.
Published: November 2004

The order of magnitude of energy emission from cusps to light bosons on ordinary cosmic string is calculated perturbatively. The analysis is applicable to both closed string loops and long cosmic strings. The perturbative result obtained here is much less than what is found by nonperturbative approximations.
ON THE POSITIVITY OF THE GRAVITATIONAL POTENTIAL IN THE QUANTUM-COSMOLOGICAL SCHRÖDINGER EQUATION
Authors: POLLOCK M.D.
Published: November 2004

Quantization of the D(=M+1)-dimensional gravitational theory with higher-derivative terms [Formula: see text] in the Friedmann space-time ds2=dt2−e2α(t)dx2, where the M-space dx2 has curvature K, yields the Schrödinger equation (Wheeler-DeWitt equation) i∂Ψ/∂t=[−AMe−Mα∂2/∂ξ2+VM,K(α, ξ)]Ψ, where ξ≡dα/dt, provided that [Formula: see text] differs from the Euler-number density. The coefficient AM is positive if there is no spin-0 tachyon in [Formula: see text] and the potential VM,K is positive semi-definite if M=3 and K=0. The theory is classically stable if the spin-2 tachyon is also absent. All of these conditions are satisfied by the heterotic superstring, after reduction to four dimensions, but not by the bosonic string, which contains a spin-2 tachyon, nor by the type-II superstring, which contains a spin-0 tachyon. After generalization to the anisotropic space-time ds2= dt2−e2β(t)dy2−e2γ(t)dz2, where dy2 and dz2 have dimensions one and two, respectively, the Schrödinger equation becomes i∂Ψ/∂t=[–(4B)−1e−(β+2γ) (X∂2/∂ζ2+Y∂2+ 2Z∂2/∂ζ∂η)+…+V(β, γ; ζ, η)]Ψ, where ζ≡dβ/dt, η≡dγ/dt. The potential V is unbounded both from above and from below for all β≠γ, for all three superstring theories, and in fact for all dimensionalities. This explains why the Universe is isotropic, and why dimensional reduction and compactification occur.
EQUATION OF STATE, MASS, RADIUS, MOMENT OF INERTIA, AND SURFACE GRAVITATIONAL REDSHIFT FOR NEUTRON STARS
Authors: BAO G. , ØSTGAARD E. , DYBVIK B.
Published: November 2004

We have calculated total masses and radii of neutron stars from the Tolman-Oppenheimer-Volkoff (TOV) equations (for matter in equilibrium in gravitational fields) and different equations of state for neutron-star matter. The calculations are done for different input central densities. We have also obtained pressure and density as functions of distance from the centre of the star, and moments of inertia and surface gravitational redshifts as functions of the total mass of the star. The maximum mass M max is for all equations of state in our calculations given by 1.65M⊙<M max <2.43M⊙ (where M⊙ is the solar mass), which agrees very well with “experimental” results. Corresponding radii R are given by 8.8 km <R<12.7 km , and a smaller central density will, in general, give a smaller mass and a larger radius.
A NEXT-GENERATION CAVITY MICROWAVE EXPERIMENT TO SEARCH FOR DARK-MATTER AXIONS
Authors: BIBBER K. VAN , STÖFFL W. , ANTHONY P.L. , SIKIVIE P. , SULLIVAN N.S. , TANNER D.B. , ŽELEZNÝ V. , GOLUBEV N.A. , KAZACHENKO O.V. , KRAVCHUK L.V. , KUZMIN V. , ROMANOV G.V. , SEKACHEV I.V. , ROSENBERG L.J. , HAGMANN C. , MOLTZ D.M. , NEZRICK F. , TURNER M.S. , VILLA F.
Published: November 2004

We propose a large-scale experimental search for dark-matter axions which may constitute an important fraction of our own galactic halo. As shown by Sikivie,1 dark-matter axions may be detected by their stimulated conversion into monochromatic microwave photons in a tunable high-Q cavity inside a strong magnetic field. The principal improvement in power sensitivity over two earlier pilot experiments (×25) derives from the large-volume high field superconducting magnet (the NASA SUMMA coils). The improvement in mass range (1.5 to 12.6 μeV) will result from the use of several microwave cavity arrays, of 2n cavities each, over the course of the experimental program, rather than a single cavity. We are participating in a joint venture with the Institute for Nuclear Research of the Russian Academy of Sciences to do R&D on metalized precision-formed ceramic microwave cavities for the axion search.
REMARKS ON THE PHASE TRANSITION IN QCD
Authors: Wilczek Frank
Published: November 2004

The significance of the question of the order of the phase transition in QCD, and recent evidence that real-world QCD is probably close to having a single second order transition as a function of temperature, is reviewed. Although this circumstance seems to remove the possibility that the QCD transition during the big bang might have had spectacular cosmological consequences, there is some good news: it allows highly non-trivial yet reliable quantitative predictions to be made for the behavior near the transition. These predictions can be tested in numerical simulations and perhaps even eventually in heavy ion collisions. The present paper is a very elementary discussion of the relevant concepts, meant to be an accessible introduction for those innocent of the renormalization group approach to critical phenomena and/or the details of QCD.
PHYSICS WITH RADIOACTIVE NUCLEAR BEAMS
Authors: BOYD RICHARD N.
Published: November 2004

The rapidly growing research area of radioactive nuclear beam physics is described. The various types of facilities used at present, and planned for the future, are discussed briefly. Then their uses in research in nuclear physics, astrophysics, and in nuclear-solid state applications are discussed. An intense effort in nuclear reaction physics has been directed toward understanding the neutron halo, a completely new result discovered for very neutron rich nuclei via the use of radioactive nuclear beams. Their use has also produced an immense amount of data on nuclear masses, lifetimes, decay modes, multipole moments, and energy levels. Other areas of research in nuclear physics with radioactive nuclear beams are less well developed, but appear to be promising. In nuclear astro-physics, several of the critical reactions of primordial and stellar nucleosynthesis have been studied. In addition, the use of radioactive nuclear beams has already provided dramatically improved definition of some of the processes of nucleosynthesis which operate near the proton and neutron drip lines, with the promise of much more detailed information to come. In more applied reasearch, the interaction between implanted nuclei and solids has often been used as a tool for nuclear physics, but the same studies can also be used to study properties of solids with previously unachievable sensitivity. The results in the past decade from radioactive nuclear beam research have been both vast and varied, but new facilities and intense interest in the research community should provide new information in the future well beyond that which presently exists.
A MASS PARAMETER FOR NUCLEAR COLLECTIVE MOTION FROM THE GENERATOR COORDINATE METHOD
Authors: ABAL G. , CANTO L.F. , DONANGELO R.J.
Published: November 2004

We calculate a mass parameter for nuclear collective motion within the framework of the Generator Coordinate Method. Two alternative phase space normalization schemes are presented, and a simple expression for the collective mass is obtained within the Gaussian Overlap Approximation. As an application, we calculate the mass parameter associated with β vibrations. A systematic study carried out in the mass range 12≤A≤100 shows pronounced shell effects. Our results in the spherical limit are shown to exceed the well known inertia for quadrapole oscillations in an irrotational fluid by a factor 2–3. It is argued that the application of this method to other problems in nuclear structure and reactions should be straightforward.
DEUTERON RADIUS AND NUCLEAR FORCES IN FREE SPACE
Authors: WONG Chun Wa
Published: November 2004

Experimental knowledge and theoretical understanding of the deuteron matter radius are reviewed. An experimental value of rm(exp)=1.9502 (20) fm is found by using the 1962 Stanford data, the 1973 Monterey data and the 1981 Mainz data for the ratio of electron-deuteron to electron-proton elastic scattering cross-sections, plus the 1979 Erevan data and the 1990 Saclay data on electron-deuteron elastic cross-sections. The theoretical radius is dominated by a model-independent part, 1.9557 (7) fm or 1.0028 rm (exp) in magnitude, determined by the triplet scattering length, the deuteron binding energy, and the triplet effective range. The remaining contribution to the theoretical radius is model-dependent. It gives about 0.0110 fm, or 0.0056 rm(exp), for the Bonn potentials which have relatively weak short-range tensor forces. Experiment and theory thus differ by 0.8%. This discrepancy cannot be understood in terms of known physical processes involving relativity, meson exchanges, and abnormal higher-mass components of the wave function. Interestingly, the five experimental results can be separated into two inconsistent groups: (a) The Stanford and Saclay results agree, giving a weighted average of 1.967 (5) fm in agreement with theory. (b) The Monterey, Mainz and Erevan results also agree, giving a weighted average of 1.9488 (21) fm in disagreement with theory. The possibility of obtaining nuclear-size information from atomic Lamb shift measurements is also reviewed. In particular, the latest deuterium-hydrogen isotope shift of the 1S-2S Lamb shift yields a deuteron matter radius of 1.963 (5) fm. New measurements of both deuteron and proton charge radii would be of great interest in both nuclear and atomic physics.
MICROSCOPIC DESCRIPTION OF THE CHARGE DENSITIES OF THE ISOTOPES 146,150Nd
Authors: GUL’KAROV I.S. , NIGAM B.P.
Published: November 2004

We analyze recent measurements of charge densities of the isotopes of neodymium on the basis of a modified shell model with fractional occupation numbers of 2p and 2d states. We calculate the transition charge densities of dipole states using the collective model of Orlandini et al. We find that this model agrees much better with the data than those of the hydrodynamic or scaling model.
THE BEST FIT VALUES OF K PARAMETER FOR (n, p) REACTIONS
Authors: GIRI MANJU , GUPTA J.P.
Published: November 2004

The semiclassical exciton model which is generally used for describing the pre-equilibrium emission at a moderate excitation energy, contains various free parameters; among them the strength factor K of the two-body residual interaction plays an important role in the computation work. With the view of fixing the free parameter K for (n, p) reactions, the excitation functions for about eight nuclei have been calculated using exciton model in combination with Hauser-Feshbach formalism. The average best fit values of the exciton model free parameter K has been found to be K=700 MeV3. Departure from this value appears to cancel out structure effects introduced into transition rates through the structure-sensitive single particle level density.
The role of NOS2 and NOS3 in renal protein and arginine metabolism during early endotoxemia in mice
Authors: Luiking Yvette C. , Hallemeesch Marcella M. , Lamers Wouter H. , Deutz Nicolaas E. P.
Published: November 2004

Previously, we observed an enhanced renal protein synthesis and increased de novo arginine production in the early response to endotoxemia in wild-type Swiss mice (Hallemeesch MM, Soeters PB, and Deutz NE. Am J Physiol Renal Physiol 282: F316–F323, 2002). To establish whether these changes are regulated by nitric oxide (NO) synthesized by NO synthase isoforms NOS2 and NOS3, we studied C57BL6/J wild-type (WT), NOS2-deficient (NOS2−/−), and NOS3-deficient (NOS3−/−) mice under baseline (unstimulated) and LPS-treated conditions. The metabolism of renal protein, amino acid, and arginine was studied at the whole body level and across the kidney by infusing the stable isotopes l-[phenyl-2H5]phenylalanine, l-[phenyl-2H2]tyrosine, l- guanidino-[15N2]arginine, and l-[ ureido-13C,2H2]citrulline. Renal blood flow was measured using radioactive PAH extraction. Under baseline conditions, renal blood flow was significantly reduced in NOS2−/−mice (0.29 ± 0.01 vs. 0.48 ± 0.07 ml·10 g body wt−1·min−1in WT) ( P < 0.05), and de novo arginine production was lower in NOS2−/−mice. After LPS challenge, renal protein turnover and arginine production increased in all three groups ( P < 0.05), even though renal de novo arginine synthesis did not increase. The expected increase in renal citrulline production and disposal after LPS was not observed in NOS2−/−mice ( P = 0.06). Collectively, these data show that NOS2 is constitutively expressed in the kidney and remarkably functional as it affects renal blood flow and de novo arginine production under baseline conditions and is important for the increase in renal citrulline turnover during endotoxemia. NOS3, in contrast, appears less important for renal metabolism. The increase in renal protein turnover during endotoxemia does not depend on NOS2 or NOS3 activity.
Synaptic Enhancement Induced Through Callosal Pathways in Cat Association Cortex
Authors: Cissé Youssouf , Crochet Sylvain , Timofeev Igor , Steriade Mircea
Published: November 2004

The corpus callosum plays a major role in synchronizing neocortical activities in the two hemispheres. We investigated the changes in callosally elicited excitatory postsynaptic potentials (EPSPs) of neurons from cortical association areas 5 and 7 of cats under barbiturate or ketamine-xylazine anesthesia. Single pulses to callosal pathway evoked control EPSPs; pulse-trains were subsequently applied at different frequencies to homotopic sites in the contralateral cortex, as conditioning stimulation; thereafter, the single pulses were applied again to test changes in synaptic responsiveness by comparing the amplitudes of control and conditioned EPSPs. In 41 of 42 neurons recorded under barbiturate anesthesia, all frequencies of conditioning callosal stimuli induced short-term (5–30 min) enhancement of test EPSPs elicited by single stimuli. Neurons tested with successive conditioning pulse-trains at different frequencies displayed stronger enhancement with high-frequency (40–100 Hz) than with low-frequency (10–20 Hz) rhythmic pulse-trains; >100 Hz, the potentiation saturated. In a neuronal sample, microdialysis of an N-methyl-d-aspartate (NMDA) receptor blocker in barbiturate-treated cats suppressed this potentiation, and potentiation of callosally evoked EPSPs was not detected in neurons recorded under ketamine-xylazine anesthesia, thus indicating that EPSPs' potentiation implicates, at least partially, NMDA receptors. These data suggest that callosal activities occurring within low-frequency and fast-frequency oscillations play a role in cortical synaptic plasticity.
On a direct construction of inverse scattering problems for integrable nonlinear evolution equations in the two‐spatial dimension
Authors: Chen H. H. , Lin J. E.
Published: November 2004

We present a method to construct inverse scattering problems for
integrable nonlinear evolution equations in the two‐spatial
dimension. The temporal component is the adjoint of the linearized
equation and the spatial component is a partial differential
equation with respect to the spatial variables. Although this idea
has been known for the one‐spatial dimension for some time, it is
the first time that this method is presented for the case of the
higher‐spatial dimension. We present this method in detail for
the Veselov‐Novikov equation and the
Kadomtsev‐Petviashvili equation.
Hamiltonian approaches of field theory
Authors: Udrişte Constantin , Teleman Ana-Maria
Published: November 2004

We extend some results and concepts of single‐time covariant
Hamiltonian field theory to the new context of multitime
covariant Hamiltonian theory. In this sense, we point out the role
of the polysymplectic structure δ ⊗ J, we prove that
the dual action is indefinite, we find the eigenvalues and the
eigenfunctions of the operator (δ ⊗ J)(∂/∂t)

with periodic boundary conditions, and we obtain interesting
inequalities relating functionals created by the new context. As
an important example for physics and differential geometry,
we study the multitime Yang‐Mills‐Witten Hamiltonian, extending the
Legendre transformation in a suitable way. Our original results
are accompanied by well‐known relations between Lagrangian and
Hamiltonian, and by geometrical explanations regarding the
Yang‐Mills‐Witten Lagrangian.
Assessment of the Bioactivity of Antibodies against β-Amyloid Peptide in vitro and in vivo
Authors: Mohajeri M. Hasan , Gaugler Meret N.M. , Martinez Julia , Tracy Jay , Li Hong , Crameri Arames , Kuehnle Katrin , Wollmer M. Axel , Nitsch Roger M.
Published: November 2004

The accumulation of the β-amyloid peptide (Aβ) is a central event in the pathogenesis of Alzheimer’s disease (AD). Aβ removal from the brain by immune therapy shows promising potential for the treatment of patients with AD, although the mechanisms of the antibody action are incompletely understood. In this study we compared the biological activities of antibodies raised against various Aβ fragments for Aβ reduction in vitro and in vivo. Antibodies against Aβ enhanced the uptake of Aβ42 aggregates up to 6-fold by primary microglial cells in vitro. The kinetics of Aβ42 uptake varied considerably among antibodies. Based on the activity to mediate Aβ42 uptake by microglial cells, we identified a bioactive antibody that significantly reduced Aβ42 levels in the brains of transgenic mice with neuronal expression of an AD-related mutated amyloid precursor protein. This effect depended on the epitopes recognized by the antibody. Our data suggest that the ability to facilitate Aβ42 uptake by primary microglia cells in vitro can be used to predict the biological activity of the antibody by passive immunization in vivo. This protocol may prove useful for the rapid validation of the activity of antibodies designed to be used in immune therapy of AD.
Protein kinase B phosphorylation of PIKfyve regulates the trafficking of GLUT4 vesicles
Authors: Berwick Daniel C. , Dell Ghislaine C. , Welsh Gavin I. , Heesom Kate J. , Hers Ingeborg , Fletcher Laura M. , Cooke Frank T. , Tavaré Jeremy M.
Published: November 2004

Insulin-stimulated glucose uptake involves the recruitment of the glucose transporter 4 isoform (GLUT4) from an intracellular location to the plasma membrane of fat and muscle cells. Although the activation of the PI3-kinase/protein kinase B (PKB) pathway is central to this effect of insulin, the key substrates for PKB that are involved require identification. Here we report that serine318 on the FYVE domain-containing PtdIns(3)P 5-kinase (PIKfyve) is a novel substrate for PKB, and show that phosphorylation stimulates the PtdIns(3)P 5-kinase activity of the enzyme. We also demonstrate that PIKfyve is phosphorylated on serine318 in intact cells in response to insulin, in a PI3-kinase-dependent manner, and that PIKfyve colocalises with a highly motile subpopulation of insulin-regulated aminopeptidase (IRAP)/GLUT4 vesicles. Finally, we demonstrate that overexpression of a PIKfyve[S318A] mutant in 3T3-L1 adipocytes enhances insulin-stimulated IRAP/GLUT4 vesicle translocation to the plasma membrane suggesting a role for PKB-dependent phosphorylation of PIKfyve in insulin-regulated IRAP/GLUT4 trafficking. The phosphorylation and activation of PIKfyve by PKB provides a novel signalling paradigm that may link plasma membrane-localised PtdIns(3,4,5)P3 signals via a protein kinase cascade to regulated PtdIns(3,5)P2 production, and thereby to the control of trafficking of other membrane cargos.
Time-Resolved Measurement of State-Specific P2X2Ion Channel Cytosolic Gating Motions
Authors: Fisher James A. , Girdler Gemma , Khakh Baljit S.
Published: November 2004

ATP-gated P2X2channels undergo permeability changes through a process that is incompletely understood. In the present study, we used fluorescence resonance energy transfer (FRET) and electrophysiology to measure cytosolic gating motions in P2X2channels as they enter a state with increased permeability. P2X2channels underwent permeability changes with a time course that was similar to decreases in FRET between cyan fluorescent protein and yellow fluorescent protein attached to the cytosolic domain of P2X2channels. Wild-type and mutant channels that did not undergo permeability changes also did not show evidence of cytosolic gating motions. Moreover, immobilizing the cytosolic domain by tethering it to the plasma membrane prevented the switch in permeability and impaired the cytosolic gating motions. Both of these phenotypes were restored when the immobilizing tether was cleaved. The data provide a time-resolved measure of state-specific gating motions and suggest how a cytosolic domain may control ion channel permeability.
A Genetic Switch for Epilepsy in Adult Mice
Authors: Krestel Heinz E. , Shimshek Derya R. , Jensen Vidar , Nevian Thomas , Kim Jinhyun , Geng Yu , Bast Thomas , Depaulis Antoine , Schonig Kai , Schwenk Frieder , Bujard Hermann , Hvalby Øivind , Sprengel Rolf , Seeburg Peter H.
Published: November 2004

Premature death from seizures afflicts gene-targeted mice expressing the Q/R site-unedited glutamate receptor subunit GluR-B(Q) of AMPA receptors in central neurons. Early seizure-related death has now been circumvented by a genetic switch that restricts GluR-B(Q) expression to forebrain principal neurons from postnatal stages onward, prominently in hippocampus and striatum and less so in cortex and amygdala. When switched on, functional receptor incorporation of GluR-B(Q) could be demonstrated by imaging evoked AMPA channel-mediated spinous Ca2+transients in CA1 pyramidal cells. Sustained GluR-B(Q) expression in adult mice led to smaller excitatory postsynaptic responses in the CA1 region with unchanged presynaptic fiber excitability. Notably, despite the smaller excitatory response, the CA1 cells exhibited a reduced population spike threshold, which might underlie the spontaneous manifestations of epilepsy, including myocloni and generalized seizures with limbic components, observed by synchronous video monitoring and electroencephalographic recordings. No neuropathological symptoms developed when GluR-B(Q) expression was restricted to only hippocampal neurons. Our results show that seizure susceptibility is triggered by GluR-B(Q) expression also in the adult brain and that circuit hyperexcitability is not an immediate consequence of GluR-B(Q) but requires yet unknown downstream events, likely to be induced by non-Hebbian plasticity from Ca2+-permeable AMPA channels in principal neurons.
Recognizing, Assessing, and Classifying Others: Cognitive Bases of Evolutionary Kinship Therapy
Authors: Bailey Kent G.
Published: November 2004

The practice of psychotherapy revolves around human relationships, especially between client and therapist. At base, psychotherapy is “a species of human interaction that establishes the therapist as a protective figure or secure base in a way that facilitates client growth and change” (Bailey, 1997). This secure interpersonal base enables the client to confront inner conflict, interpersonal conflict/deficiencies, and negative thoughts about the self and others (see Gilbert this volume). Evolutionary kinship therapy views the client-therapist relationship, and client relations with others, through an evolutionary lens that focuses on the role that ancestral human relationships played in shaping current social behavior (Bailey, 2000; Bailey & Wood, 1998). This article outlines psychological kinship theory and then applies the logic of the model to selected aspects of the client-therapist relationship.
Childhood Emotional Maltreatment, Cognitive Vulnerability to Depression, and Self-Referent Information Processing in Adulthood: Reciprocal Relations
Authors: Steinberg Jennifer A. , Gibb Brandon E. , Alloy Lauren B. , Abramson Lyn Y.
Published: November 2004

Previous work has established a relationship between reports of childhood emotional maltreatment and cognitive vulnerability to depression, as well as an association between cognitive vulnerability and self-referent information-processing biases. Findings from this study of individuals at low (LR) and high (HR) cognitive risk for depression revealed a relationship between reports of childhood emotional maltreatment and current information processing biases. Specifically, individuals with greater childhood emotional maltreatment exhibited more negative self-referent information processing. Moreover, cognitive risk mediated the relationship between childhood emotional maltreatment and these information-processing biases. Testing an alternate model, information-processing biases also mediated the relationship between childhood emotional maltreatment and cognitive risk.
The governance of innovation
Authors: Campbell W B , Barnett D B
Published: November 2004

How new operations should be monitored
Direct Observation of Anion‐Mediated Translocation of Fluorescent Oligoarginine Carriers into and across Bulk Liquid and Anionic Bilayer Membranes
Authors: Sakai Naomi , Takeuchi Toshihide , Futaki Shiroh , Matile Stefan
Published: November 2004

The recent hypothesis that counteranion‐mediated dynamic inversion of charge and solubility might contribute to diverse functions of oligoarginines in biomembranes was tested with two fluorescently labelled oligomers, FL‐R8, one of the most active cell‐penetrating peptides, and its longer version, FL‐R16. We report evidence for counteranion‐mediated phase transfer from water into bulk chloroform and anionic lipid‐bilayer membranes as well as reverse‐phase transfer from bulk chloroform and across intact lipid‐bilayer membranes into water. The differences found between FL‐R8 and FL‐R16 with regard to location in the bilayer and reverse‐phase transfer from bulk and lipid‐bilayer membranes into water implied that the reported results may be relevant for biological function.
Polymerisierungskinetik von Kieselsäure
Authors: Ozmetin C. , Schlomach J. , Kind M.
Published: November 2004

No abstracts.
Applying pharmacogenomics in drug development: Call for collaborative efforts
Authors: Gurwitz David
Published: November 2004

Personalized medicine remains the long‐awaited next revolution in medicine. So far, progress towards this change has been much slower than hoped, given that our entire DNA sequence has been publicly available since April 2001. Three years down the road, it has become clear that the expectations for fast progress in medicine were excessive, and that our genome is by far more complex than originally perceived. Moreover, it seems that both the medical profession and health care systems, as well as pharmaceutical companies, are too conservative for modifying diagnostic and treatment protocols following the gain of new pharmacogenomics knowledge that has the potential to drastically reduce the incidence rates of adverse drug reactions. The next few years may well be a crucial turning point for the use of pharmacogenomics data in drug development. The transformation will hopefully begin with the availability of FDA approved rapid and reliable diagnostic screening tools for CYP450 alleles, along with new FDA guidelines favoring the approval process for drug applications supported by valuable genomic information related to toxic reactions. The current theme issue, a focused snapshot for mid‐2004, highlights some of the vital topics in clinical genetics and informatics that together will hopefully form a platform for future joint efforts to identify the most valuable genotype/drug response phenotype correlations. Dialogue and collaboration between regulatory agencies and the pharmaceutical industry, as well as within the pharmaceutical sector, will be indispensable for advancing beyond this turning point towards genuine personalized medicine. Drug Dev. Res. 62:71–75, 2004. © 2004 Wiley‐Liss, Inc.