bluuebunny/crossref_metadata_2025 huggingface dataset:
Lagrangian–Hamiltonian unified formalism for field theory
Authors: Echeverrı́a-Enrı́quez Arturo , López Carlos , Marı́n-Solano Jesús , Muñoz-Lecanda Miguel C. , Román-Roy Narciso
Published: December 2003

The Rusk–Skinner formalism was developed in order to give a geometrical unified formalism for describing mechanical systems. It incorporates all the characteristics of Lagrangian and Hamiltonian descriptions of these systems (including dynamical equations and solutions, constraints, Legendre map, evolution operators, equivalence, etc.). In this work we extend this unified framework to first-order classical field theories, and show how this description comprises the main features of the Lagrangian and Hamiltonian formalisms, both for the regular and singular cases. This formulation is a first step toward further applications in optimal control theory for partial differential equations.
Edge turbulent transport with lower hybrid current drive in the Hefei Tokamak-7
Authors: Ding B. J. , Kuang G. L. , Shan J. F. , Song M. , Xu G. S. , Wan B. N. , Zhao Y. P. , Li J. G.
Published: December 2003

The edge plasma transport around the last closed flux surface was investigated using Langmuir probes in a lower hybrid current drive (LHCD) experiment in the Hefei Tokamak-7 [J. K. Xie et al., in Proceedings of the 16th International Conference on Fusion Energy, Montreal, 1996 (International Atomic Energy Agency, Vienna, 1997), Vol. 1, p. 685]. Fluctuations of plasma density, plasma temperature, and poloidal electric field in the boundary plasma are reduced, hence the electrostastic turbulence-induced particle flux and heat flux both significantly decrease after the application of LHCD. The suppression of density fluctuation is more sensitive to the lower hybrid wave (LHW) than that of temperature fluctuation, which is in agreement with the model proposed by Ware in the presence of flow shear [A. S. Ware et al., Phys. Plasmas 5, 173 (1998)]. The difference between turbulent convective and conductive fluxes depends on such a discrepancy between normalized density fluctuation and temperature fluctuation. It is speculated that the reduced turbulence-induced transport is possibly attributable to a sheared flow resulting from the varying radial electric field, which is formed possibly due to the loss of the energetic electron generated by LHW. In addition, studies show that the effect of magnetohydrodynamic activity, possibly modified by LHCD, on plasma transport could be another possible candidate for the reduced electrostatic turbulent flux.
The Hall instability in accelerated plasma channels
Authors: Liverts Edward , Mond Michael
Published: December 2003

The Hall instability of a perfectly conducting plasma is studied. The two-dimensional magnetohydrodynamic equations for systems with large Larmor radius for a two-fluid model in which the Hall term is taken into account in Faraday’s law, are investigated. By using a linearized theory it is shown, that the plasma may become unstable under small perturbations. This instability is driven by the plasma acceleration in channel. The most unstable perturbations propagate in the direction where the wave vector is orthogonal to the magnetic field.
Low dimensional cohomology of general conformal algebras gcN
Authors: Su Yucai
Published: December 2003

We compute the low dimensional cohomologies H̃q(gcN,C), Hq(gcN,C) of the infinite rank general Lie conformal algebras gcN with trivial coefficients for q⩽3, N=1 or q⩽2, N⩾2. We also prove that the cohomology of gcN with coefficients in its natural module is trivial, i.e., H*(gcN,C[∂]N)=0, and thus partially solve an open problem of Bakalov–Kac–Voronov [Commun. Math. Phys., 200, 561–598 (1999)].
Spatial regimes in the dynamics of polyolefins: Self-motion
Authors: Neelakantan Arun , Maranas Janna K.
Published: December 2003

Molecular dynamics simulations are used to investigate the spatial dependence of dynamics in a series of polyolefins. The dynamic indicator used is the self-intermediate scattering function, which parallels the observable in an incoherent quasielastic neutron scattering experiment such as time of flight or backscattering. As with neutron time of flight experiments, two processes are evident. The fast process is a single exponential, and has relaxation times that scale as q−2, where q is the momentum transfer. The slow process is the stretched exponential decay usually associated with the motion underlying the glass transition. The stretching exponent is a function of spatial scale, with the minimum values occurring near the spatial scale of interchain packing. Relaxation times for the slow process scale as q−2/β for all materials investigated. The relative contribution of the two processes is a function of spatial scale, with the crossover from fast to slow dynamics at the location of closest possible interchain contacts, which is approximately three times the cage size. These observations apply equally well to the four materials considered. We consider the relative ordering of relaxation times of the series in light of their local chain architecture. This ordering varies depending on the observable calculated.
Numerical modeling of nonlinear growth and saturation of neoclassical tearing modes
Authors: Yu Q. , Günter S. , Lackner K.
Published: December 2003

Numerical modeling results of the nonlinear growth and saturation of neoclassical tearing modes are presented and compared with analytical theories. The saturated magnetic island width obtained numerically in most cases approximately agrees with that derived from generalized Rutherford equation. For a high bootstrap current density fraction and/or a small magnetic shear at the rational surface, however, the change of the local magnetic shear due to the loss of the bootstrap current inside the island should be taken into account in calculating the saturated island width. At island saturation the tearing mode stability index, Δ′, is found to approximately agree with that found from the linear outer region equation of the tearing mode and to linearly decrease with the saturated island width. During the growth of the island, however, the value of Δ′ depends not only on the island width but also on other parameters which affect the plasma current density profile.
Boundary effects of molecular diffusion in nanoporous materials: A pulsed field gradient nuclear magnetic resonance study
Authors: Geier Oliver , Snurr Randall Q. , Stallmach Frank , Kärger Jörg
Published: December 2003

The boundary conditions of intraparticle diffusion in nanoporous materials may be chosen to approach the limiting cases of either absorbing or reflecting boundaries, depending on the host–guest system under study and the temperature of measurement. Pulsed field gradient nuclear magnetic resonance is applied to monitor molecular diffusion of n-hexane and of an n-hexane–tetrafluoromethane mixture adsorbed in zeolite crystallites of type NaX under either of these limiting conditions. Taking advantage of the thus-established peculiarities of mass transfer at the interface between the zeolite bulk phase and the surrounding atmosphere, three independent routes for probing the crystal size are compared. These techniques are based on (i) the measurement of the effective diffusivity under complete confinement, (ii) the application of the so-called NMR tracer desorption technique, and (iii) an analysis of the time dependence of the effective diffusivity in the short-time limit where, by an appropriate variation of the adsorbate and the measuring conditions, the limiting cases of reflecting and adsorbing boundaries could be considered. All these techniques are found to yield coinciding results, which are in excellent agreement with the crystal sizes determined by microscopy.
Improved convergence in block copolymer self-consistent field theory by Anderson mixing
Authors: Thompson R. B. , Rasmussen K. O/. , Lookman T.
Published: December 2003

A modification to real space polymeric self-consistent field theory algorithms that greatly improves the convergence properties is presented. The method is based on Anderson mixing [D. G. Anderson, J. Assoc. Comput. Mach. 12, 547 (1965)], and each iteration computed takes negligibly longer to perform than with other methods, but the number of iterations required to reach a high accuracy solution is greatly reduced. No a priori knowledge of possible phases is required to apply this method. We apply our approach to a standard diblock copolymer melt, and demonstrate iteration reductions of more than a factor of 5 in some cases.
Kinetics of phase transformation on a Bethe lattice
Authors: Berim Gersh O. , Ruckenstein Eli
Published: December 2003

A kinetic Ising model is applied to the description of phase transformations on a Bethe lattice. A closed set of kinetic equations for a model with the coordination number q=3 is obtained using a procedure developed in a previous paper. For T close to Tc (T>Tc), where Tc is the phase transition temperature, and zero external field (absence of supersaturation), the rate of phase transformation (RPT) for small deviations from equilibrium is independent of time and tends to zero as (T−Tc). At T=Tc, the RPT depends on time and for large times behaves as t−1. For T<Tc, we examine the transformation from the initial state with almost all spins “down” to the state with almost all spin “up” after the external field jumped from Bi<0 to Bf>0. The role of different mechanisms responsible for growth (decay), splitting (coagulation), and creation (annihilation) of clusters are examined separately. In all cases there is a critical value Bc of the external field, such that the phase transformation takes place only for Bf>Bc. This result is also obtained from a more simple consideration involving spherical-like clusters on a Bethe lattice. The characteristic time tR at which the polarization becomes larger than zero diverges as (Bf−Bc)−b for Bf→Bc with b=0.47. The RPT has a rapid growth near tR and remains constant for t>tR. The average cluster size (number of spins in a cluster) exhibits a rapid unrestricted growth at a time td≃tR which indicates the creation of infinite clusters. The only exception to the latter behavior occurs when the kinetics is dominated by cluster growth and decay processes. In this case, the average cluster size remains finite during the transformation process. In contrast to the classical theory, the present approach does not separate the processes of creation of clusters of critical size (nucleation) and of their growth, both being accounted for by the kinetic equations employed.
Voronoi space division of a polymer: Topological effects, free volume, and surface end segregation
Authors: Tokita Nakako , Hirabayashi Megumi , Azuma Chiaki , Dotera Tomonari
Published: December 2003

In order to investigate the topological effects of chain molecules, united-atom molecular dynamics simulations of a 500-mer polyethylene linked by 50 hexyl groups (a grafted polymer having 52 ends) are carried out and analyzed in terms of Voronoi space division. We find that the volume of a Voronoi polyhedron for a chain end is larger than that for an internal or junction atom, and that it is the most sensitive to temperature, both of which suggest higher mobility of chain ends. Moreover, chain ends dominantly localize at the surface of the globule: The striking evidence is that while the ratio of surface atoms is only 24% of all atoms, the ratio of ends at the surface is 91% out of all ends. The shape of Voronoi polyhedra for internal atoms is prolate even in the bulk, and near the surface it becomes more prolate. We propose the concept of bonding faces, which play a significant role in the Voronoi space division of covalently bonding polymers. Two bonding faces occupy 38% of the total surface area of a Voronoi polyhedron and determine the prolate shape.
Interplay of energetic ions and Alfvén modes in helical plasmas
Authors: Kolesnichenko Ya. I. , Yamamoto S. , Yamazaki K. , Lutsenko V. V. , Nakajima N. , Narushima Y. , Toi K. , Yakovenko Yu. V.
Published: December 2003

Alfvén eigenmodes and their destabilization by energetic ions in stellarators, mainly, in the Large Helical Device (LHD) [M. Fujiwara, K. Kawahata, N. Ohyabu et al., Nucl. Fusion 41, 1355 (2001)] plasmas, are considered. A general expression for the instability growth rate is derived, which generalizes that obtained by Ya. I. Kolesnichenko et al. [Phys. Plasmas 9, 517 (2002)] by taking into account the finite magnitude of the perturbed longitudinal magnetic field. The structures of the Alfvén continuum and Alfvén eigenmodes, as well as the resonances of the wave–particle interaction, are studied. A numerical simulation of the destabilization of Alfvén waves with low mode numbers during neutral-beam injection in a particular LHD shot is carried out. The obtained solutions represent even and odd core-localized toroidicity-induced Alfvén eigenmodes, the calculated frequencies and the mode numbers being in agreement with experimental data. The growth rates of the instabilities are calculated.
Accurate double many-body expansion potential energy surface for triplet H3+. II. The upper adiabatic sheet (2 3A′)
Authors: Viegas Luis P. , Cernei Mihail , Alijah Alexander , Varandas António J. C.
Published: December 2003

We report on a global potential energy hypersurface for the upper sheet of the lowest triplet state of H3+. The analytic representation is based on the double many-body expansion theory. The ab initio data points, calculated with a large cc-pV5Z basis, are represented with a root mean square deviation of only 5.54 cm−1 in the energy region below the H++2H(2S) dissociation threshold. The quasi-bound vibronic states supported by this surface have also been calculated.
Improved thermal stability of Langmuir–Blodgett films through an intermolecular hydrogen bond and metal complex
Authors: Du Xuezhong , Liang Yingqiu
Published: December 2003

Langmuir–Blodgett (LB) films of N-octadecanoyl-L-alanine and its silver and zinc complexes have been investigated by variable-temperature Fourier transform infrared transmission spectroscopy. The thermal stability of LB films is improved through an intermolecular hydrogen bond and metal complex. The intermolecular hydrogen-bonding interaction between hydrophilic head groups in the same monolayers and the metal complex between one head group and another in the neighboring monolayers considerably increase the interaction between the corresponding hydrophobic alkyl chains. It is shown that the transformation of the triclinic subcell packing of the molecules in the LB films prior to and after the silver complex into hexagonal packing occurs before the phase transition accompanied with a change in molecular orientation. The phase transition behavior of the LB films is varied from a small temperature interval to large one depending on the hydrogen bond and metal complex.
Long-time and unitary properties of semiclassical initial value representations
Authors: Harabati C. , Rost J. M. , Grossmann F.
Published: December 2003

We numerically compare the semiclassical “frozen Gaussian” Herman–Kluk propagator [Chem. Phys. 91, 27 (1984)] and the “thawed Gaussian” propagator put forward recently by Baranger et al. [J. Phys. A 34, 7227 (2001)] by studying the quantum dynamics in some nonlinear one-dimensional potentials. The reasons for the lack of long-time accuracy and norm conservation in the latter method are uncovered. We amend the thawed Gaussian propagator with a global harmonic approximation for the stability of the trajectories and demonstrate that this revised propagator is a true alternative to the Herman–Kluk propagator with similar accuracy.
Evaluating the accuracy of a density functional theory of polymer solutions with additive hard sphere diameters
Authors: Forsman Jan , Woodward Clifford E.
Published: December 2003

We assess the accuracy of a density functional theory for athermal polymer solutions, consisting of solvent particles with a smaller radius than that of the monomers. The monomer and solvent density profiles in a slit bound by hard, flat, and inert surfaces are compared with those obtained by a Metropolis Monte Carlo simulation. At the relatively high density at which the comparison is performed, there are considerable packing effects at the walls. The density functional theory introduces a simple weight function to describe nonlocal correlations in the fluid. A recent study of surface forces in polymer solutions used a different weighting scheme to that proposed in this article, leading to less accurate results. The implications of the conclusions of that study are discussed.
Impurity-stimulated heterogeneous nucleation of supercooled H2 clusters
Authors: Knuth Eldon , Schaper Sven , Toennies J. Peter
Published: December 2003

The sizes and mass spectra of large (N̄=1900–13 700 molecules) cold (∼3.1 K) H2 clusters have been measured after scattering from CO molecules. Cluster-size measurements after between 2 and 8 collisions indicate that 7% of the H2 molecules are evaporated. This loss agrees with calculations for the number of H2 molecules evaporated by the heat released in the transition from an initial liquid state to a final solid state. Even though heterogeneous nucleation is initiated after only a few collisions with CO molecules, the mass spectra show that additional captured CO molecules coagulate to form large CO clusters with up to n=11 molecules, suggesting that the outer layer is sufficiently liquidlike to facilitate mobility of the CO molecules. Since the calculated H2 cluster temperature (∼3.1 K) is below the superfluid transition temperature predicted for pH2 with density between 40% and 80% of the triple-point density, a shell-like region of low density near the cluster surface can be expected to be superfluid.
Towards an assessment of the accuracy of density functional theory for first principles simulations of water
Authors: Grossman Jeffrey C. , Schwegler Eric , Draeger Erik W. , Gygi François , Galli Giulia
Published: December 2003

A series of Car–Parrinello (CP) molecular dynamics simulations of water are presented, aimed at assessing the accuracy of density functional theory in describing the structural and dynamical properties of water at ambient conditions. We found negligible differences in structural properties obtained using the Perdew–Burke–Ernzerhof or the Becke–Lee–Yang–Parr exchange and correlation energy functionals; we also found that size effects, although not fully negligible when using 32 molecule cells, are rather small. In addition, we identified a wide range of values of the fictitious electronic mass (μ) entering the CP Lagrangian for which the electronic ground state is accurately described, yielding trajectories and average properties that are independent of the value chosen. However, care must be exercised not to carry out simulations outside this range, where structural properties may artificially depend on μ. In the case of an accurate description of the electronic ground state, and in the absence of proton quantum effects, we obtained an oxygen–oxygen correlation function that is overstructured compared to experiment, and a diffusion coefficient which is approximately ten times smaller.
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multiple-quantum nuclear magnetic resonance investigations of molecular order in polymer networks. II. Intensity decay and restricted slow dynamics
Authors: Saalwächter Kay
Published: December 2003

We present an approach towards the analysis of the intensity decay in proton multiple-quantum experiments on polymeric networks in terms of slow fluctuations of the residual dipole–dipole coupling tensor. Solutions for individual spin pairs as well as the three-spin system of methyl groups are derived, and the influence of the cycle time of the multiple-quantum pulse sequence is evaluated. The multiple-quantum strategy discussed herein features the advantage that the magnitude of the fluctuating part of the residual dipole–dipole coupling constant and the correlation time of the slow process can be determined independently of the integral residual coupling constant as well as its distribution. The theory is applied to experiments on end-linked poly(dimethylsiloxane) model networks with mono- and bimodal chain length distributions, where it is found that, for all samples, correlation times of the slow processes average to about 1 ms, and that the magnitude of the fluctuating part of the dipole–dipole coupling is significantly smaller than the average dipole–dipole coupling constant. This observation is interpreted in terms of considerably restricted reorientations of topological constraints.
Numerical studies of a steady state axisymmetric co-axial helicity injection plasma
Authors: Tang X. Z. , Boozer A. H.
Published: December 2003

Steady state current profile, plasma potential, and plasma flow of an electrostatically driven co-axial helicity injection (CHI) plasma with axisymmetry are numerically investigated using both an open field line Grad–Shafranov equilibrium model and self-consistent initial value magnetohydrodynamic (MHD) simulations. For CHI plasmas, the Grad–Shafranov model ignores plasma inertia but not a perpendicular, or Grad–Shafranov, flow. The Grad–Shafranov flow is the result of the gradient of Grad–Shafranov potential across magnetic field lines, and is responsible for toroidal current drive. Numerical Grad–Shafranov solutions show that as the characteristic CHI discharge parameter, the normalized voltage V̂≡μ0V/ηB0q0, becomes order of unity, CHI plasma develops kink-unstable hollow current profile. Here 𝒱 is the imposed voltage, η the plasma resistivity, q0 the toroidal and injector poloidal flux ratio, and B0≡4χ0/ab a nominal poloidal field defined by the injector poloidal flux χ0, plasma minor radius a, and plasma elongation b/a. When a small plasma inertia is included in the equation of motion, such as that in a time dependent MHD calculation, the modification on the perpendicular current is small, but its impact on parallel current distribution and hence the spatial dependence of magnetic flux can be great through the Pfirsch–Schlüter-like effects.
Hydrodynamics of microplasmas from thin foils exploded by picosecond laser pulses
Authors: Squillacioti Paola , Galimberti Marco , Labate Luca , Tomassini Paolo , Giulietti Antonio , Shibkov Valery , Zamponi Flavio
Published: December 2003

Thin plastic foils have been exploded by 30 ps laser pulses at an intensity ranging from 1014 to 1015 W/cm2. The hydrodynamic evolution of the plasma has been studied by interferometry for two different foil thicknesses, 300 and 900 nm, respectively. The plasma produced beyond the foil systematically shows a different dynamics in the two cases. In the case of 300 nm foil, such a dynamics appears to be driven by the radiation pressure of the laser pulse. This explanation is supported by two-dimensional simulation.
Monopole–antimonopole solutions of the Skyrmed SU(2) Yang–Mills–Higgs model
Authors: Paturyan Vanush , Tchrakian D. H.
Published: December 2003

Axially symmetric monopole–antimonopole dipole solutions to the second-order equations of a simple SU(2) Yang–Mills–Higgs model featuring a quartic Skyrme-like term are constructed numerically. The effect of varying the Skyrme coupling constant on these solutions is studied in some detail.
Towards an accurate representation of electrostatics in classical force fields: Efficient implementation of multipolar interactions in biomolecular simulations
Authors: Sagui Celeste , Pedersen Lee G. , Darden Thomas A.
Published: December 2003

The accurate simulation of biologically active macromolecules faces serious limitations that originate in the treatment of electrostatics in the empirical force fields. The current use of “partial charges” is a significant source of errors, since these vary widely with different conformations. By contrast, the molecular electrostatic potential (MEP) obtained through the use of a distributed multipole moment description, has been shown to converge to the quantum MEP outside the van der Waals surface, when higher order multipoles are used. However, in spite of the considerable improvement to the representation of the electronic cloud, higher order multipoles are not part of current classical biomolecular force fields due to the excessive computational cost. In this paper we present an efficient formalism for the treatment of higher order multipoles in Cartesian tensor formalism. The Ewald “direct sum” is evaluated through a McMurchie–Davidson formalism [L. McMurchie and E. Davidson, J. Comput. Phys. 26, 218 (1978)]. The “reciprocal sum” has been implemented in three different ways: using an Ewald scheme, a particle mesh Ewald (PME) method, and a multigrid-based approach. We find that even though the use of the McMurchie–Davidson formalism considerably reduces the cost of the calculation with respect to the standard matrix implementation of multipole interactions, the calculation in direct space remains expensive. When most of the calculation is moved to reciprocal space via the PME method, the cost of a calculation where all multipolar interactions (up to hexadecapole–hexadecapole) are included is only about 8.5 times more expensive than a regular AMBER 7 [D. A. Pearlman et al., Comput. Phys. Commun. 91, 1 (1995)] implementation with only charge-charge interactions. The multigrid implementation is slower but shows very promising results for parallelization. It provides a natural way to interface with continuous, Gaussian-based electrostatics in the future. It is hoped that this new formalism will facilitate the systematic implementation of higher order multipoles in classical biomolecular force fields.
Slow- and helicon-wave sustained discharges in HF/VHF bands of radio frequency
Authors: Sakawa Youichi , Kunimatsu Hiroyuki , Kikuchi Hideki , Fukui Yasuaki , Shoji Tatsuo
Published: December 2003

Helicon-wave sustained (HW) and slow-wave sustained (SW) discharges are studied in a whistler- or helicon-wave range of frequency using high-frequency (13.56 MHz) and very-high-frequency (50 and 144 MHz) bands of rf. For 13.56 and 50 MHz, in addition to capacitive-coupling (E) discharge and the HW discharge, the SW discharge is observed at an extremely low rf power and plasma density; lower than the E discharge region. For 144 MHz, no E discharges appear and the transition from the SW discharge to the HW discharge occurs. In the SW discharge, both the electromagnetic and electrostatic waves are observed. The results of two-dimensional wave code and analytic calculation indicate that the electrostatic component of the electric field parallel to a static magnetic field is dominant in plasma production in the SW discharge.
Beam deposition model for energetic electron transport in inertial fusion: Theory and initial results
Authors: Manheimer Wallace , Colombant Denis
Published: December 2003

A new model is proposed for calculation of the effect of energetic electron transport in inertial fusion. Regions of large temperature gradient are approximated as sources of monoenergetic electron beams which then scatter and deposit their energy in the plasma. For short mean free path, one recovers the classical theory. In regions of high temperature gradient, the model seems to describe nonlocal heat deposition and flux inhibition in qualitatively the same way as much more cumbersome Fokker–Planck simulations. Furthermore, the model contains virtually no free parameters. Finally the effect of this nonlocal deposition and flux inhibition is calculated for laser pellets imploded with Megajoule class lasers.
Swainsona sejuncta: a species of ornamental promise or a potential weed?
Authors: Martyn A. , Tyler J. , Offord C. , McConchie R.
Published: December 2003

The potential for indigenous species to establish outside their natural range and become weeds is less well recognised than the potential for exotic species to become weeds. In this study, the weed potential of a native Australian legume, Swainsona sejuncta Joy Thomps., was assessed using weed risk assessment protocols (the 'Pheloung system') and germination experiments. The Pheloung system uncovered several traits indicating that S.�sejuncta has significant weed potential. These traits include production of the toxin swainsonine, a short generative time, production of large numbers of viable seeds, and formation of a dense canopy. The species appears to benefit from cultivation, and seedlings emerged along paths surrounding garden beds. The Pheloung system did not give a definitive outcome for rejection or acceptance (high or low weed potential, respectively) but indicated that further evaluation is required. However, if S. sejuncta naturalises outside its limited native range in the future, then the species would be considered to have a high weed potential. Experiments in addition to the Pheloung system showed that S. sejuncta germinated rapidly over a wide range of temperatures once the seed coat was broken, reflecting a high competitive ability. Consequently, cultivation and commercialisation of S. sejuncta as an ornamental plant is not recommended without further research.
Rooting of peach hardwood and semi-hardwood cuttings
Authors: Tsipouridis C. , Thomidis T. , Isaakidis A.
Published: December 2003

The influence of some external factors important for the rooting of semi-hardwood and hardwood peach cuttings planted in a mist propagation unit with a bottom heat bench were investigated. Cuttings from 1-year-old trees had relatively higher rooting percentages after storage at 2–4�C for 2 and 3 months, while cuttings from 11-year-old trees had the highest rooting percentage at the first planting. Cold storage appeared to decrease rooting of the cuttings from 11-year-old trees significantly. The greatest length of semi-hardwood cuttings was 15–20 cm long. Hardwood cuttings collected from the middle of the shoot on 4 November gave the best results. Spring Crest, Arm King and GF677 had the highest rooting percentages (averaged across all levels), while the cultivars Andross, Flavour Crest and Katerina rooted poorly. The effect of 5 indole-3-butyric acid (IBA) concentrations on the rooting of peach hardwood cuttings were also tested. Generally, IBA concentration at rates of 2000 mg/L gave very good rooting.
Evaluation of the usefulness of senescing agent potassium iodide for assessing inter-cultivar variation for drought tolerance in pearl millet [Pennisetum glaucum (L.) R.Br.]
Authors: Ashraf M. , Arfan M. , Ahmad A.
Published: December 2003

Drought stress is an important limitation to the growth and grain yield of pearl millet in arid and semi-arid regions of the world. Potassium iodide, a senescing agent, was used as a screening tool for evaluating drought tolerance of 22 strains of pearl millet at the grain development stage (grain filling) under glasshouse conditions. In order to use potassium iodide as a selection method in breeding programs for improvement of drought tolerance, the technique was compared with some drought evaluating parameters such as water retention capability, osmotic adjustment, photosynthetic capacity and water-use efficiency. Application of a 0.3% solution of potassium iodide at anthesis was very effective in causing drought stress, and hence grain yield reduction, in pearl millet. It showed a significant association with water deficit in growth attributes such as fresh and dry weights of shoots, and grain yield. Osmotic adjustment, water retention capability (decrease in weight of excised leaves during 5-h drying period), photosynthetic rate, and single-leaf water-use efficiency (net CO2 assimilation rate/transpiration) did not show positive relationships with the degree of drought tolerance measured using potassium iodide spray or water-deficit treatment. A large amount of variation in drought tolerance observed in 22 lines of pearl millet can be of considerable practical value. For example, the 3 lines ICMP-83720, ICMV-9413 and ICMV-94472, ranked as highly drought tolerant on the basis of their overall growth and physiological performance, and could be of direct use under mild drought conditions.
Survival and growth of the tree species and provenances in response to salinity on a discharge site
Authors: Marcar N. E. , Crawford D. F. , Hossain A. K. M. A. , Nicholson A. T.
Published: December 2003

The survival and growth of 24 native tree species planted in 2 trials on a saline discharge site, which had a soil salinity gradient as well as watertable depth and salinity, near Wellington in central-west New South Wales were investigated. Several provenances of some species (including Acacia stenophylla, Eucalyptus camaldulensis and E. spathulata) and clones of E. camaldulensis and E. spathulata, were also evaluated. Each accession was represented by a 5-tree row plot with 8 replications. Root-zone salinity (ECe 0–60 cm) at the tree and plot level was calculated from in situ measurements of bulk soil salinity using an EM-38 device (Geonics, Canada). Growth measurements are reported at 72 (trial 1) and 61 months (trial 2) after planting. For each trial, 4 replicates were classified as either non-saline (mean ECe <2 dS/m) or saline (ECe range from about 6 to 10 dS/m). Watertable depths varied from 0 to 1.5 m (depending on season) in the saline areas to >4 m in the non-saline, upslope areas. Survival and growth differed significantly between species, provenances and clones in both trials and under both saline and non-saline conditions. For most accessions, trees survived and grew better under non-saline conditions. Under non-saline conditions A. mearnsii, E. camaldulensis and E. occidentalis performed best; for example, A.�mearnsii (16268) attained a mean height of 7 m and mean DBH of 11 cm at 61 months in trial 2. Under saline conditions, A. stenophylla, E. camaldulensis, E. occidentalis and E. spathulata performed best; for example, E.�occidentalis attained a height of 6.9 m height and 12.3 cm DBH after 61 months in trial 2. Responses of selected species to root-zone salinity are provided; significant differences were found between species with E. occidentalis and A. stenophylla showing no growth decline up to ECe of 10 dS/m, while most other species showed varying rates of decline with increasing salinity. Three years after thinning each trial, good coppice regrowth was observed from cut stumps of all species except A. mearnsii and Melaleuca halmaturorum.
Food availability for the dibbler (Parantechinus apicalis) on Boullanger and Whitlock Islands, Western Australia
Authors: Miller Susan , Bencini Roberta , Mills Harriet , Moro Dorian
Published: December 2003

The aim of this study was to assess food availability for the dibbler (Parantechinus apicalis) on Boullanger and Whitlock Islands in different habitats and seasons. This was assessed by capturing ground-dwelling invertebrates in pitfall traps in winter, spring and autumn. A quantitative faecal-pellet analysis was conducted to determine the composition of the diet. There were no significant differences in the number of invertebrates captured in the different seasons, or in the different habitat types on the islands. The proportion of plant versus animal matter in the faecal pellets did not change significantly between the seasons. The diet consisted of ~20% plant material. The scat analysis showed that dibblers consumed at least 10 orders of invertebrates ranging in length from 0.1 mm to 25 mm with an average size of 4.5 ± 0.4 mm. The dibblers did not select for a particular size or taxon of prey, but fed on any invertebrates that were readily available to them. This suggests that dibblers are essentially insectivorous dietary generalists and opportunists. The information gathered in this study could be applied when considering available food resources at future translocation sites for dibblers.
Environmental factors have little influence on the reproductive activity of the Iberian hare (Lepus granatensis)
Authors: Alves P. C. , Rocha A.
Published: December 2003

The two European hare species with the largest ranges, the brown hare (Lepus europaeus) and the mountain hare (L. timidus), have a marked seasonal pattern of reproduction, probably reflecting strong environmental influences during the year. In this work, we evaluate the role of some environmental factors on the reproductive activity of another European hare species, the Iberian hare (L. granatensis). The study was carried out in Pancas, southern Portugal, from mid-1997 through December 1999. Climatic data (mean monthly values of minimum and maximum air temperature, daylength and total monthly rainfall) were recorded at the nearest meteorological station. To assess abundance and quality of food, samples of the herbaceous vegetation were collected every two months and analysed for water, fibre and crude protein content. Iberian hares were collected every two months and live or post mortem analyses were performed. The proportion of males with external testes and of pregnant females as well as the weight of the gonads were recorded. While environmental variables had marked seasonal variations, the Iberian hare nevertheless showed continuous reproductive activity. In all sampled periods, males with external testes and pregnant females were observed. However, a slight decrease of sexual activity appears to occur, mainly in males, during autumn. Only the variation of male reproductive characteristics was significantly explained by multiple regression equations. Maximum regression coefficients were obtained with the climatic variables (minimum, maximum temperatures and daylength) and vegetation biomass of the preceding two months. Our data indicate that environmental factors have little effect on reproduction in the Iberian hare. The results are compared with those obtained for other phylogenetically and geographically close hare species, and with another leporid, the wild rabbit (Oryctolagus cuniculus algirus), which occurs sympatrically with L. granatensis.
Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. III. Broad-scale patterns of habitat use
Authors: Sullivan B. J. , Baxter G. S. , Lisle A. T.
Published: December 2003

To date there have been few quantitative studies of the distribution of, and relative habitat utilisation by, koalas in the mulgalands of Queensland. To examine these parameters we applied habitat-accessibility and relative habitat-utilisation indices to estimates of faecal pellet density sampled at 149 sites across the region. Modelling the presence of pellets using logistic regression showed that the potential range of accessible habitats and relative habitat use varied greatly across the region, with rainfall being probably the most important determinant of distribution. Within that distribution, landform and rainfall were both important factors affecting habitat preference. Modelling revealed vastly different probabilities of finding a pellet under trees depending on the tree species, canopy size, and location within the region.
Investigation of alternative baits for rabbit control, and the examination of the distribution and longevity of 1080 in One-shot oats
Authors: Twigg Laurie E. , Lowe Tim J. , Kirkpatrick Winifred E. , Martin Gary R.
Published: December 2003

The use of 1080-poisoned oats in rabbit-control programs has become less effective in some areas of Australia. Consequently, factors likely to influence the effectiveness of this bait, and alternative grain products for rabbit control, were investigated. Vacuum impregnation rates with 1080 (sodium monofluoroacetate) for malted and unmalted barley were such that all barley products tested could be used as bait material in conventional rabbit-control programs where individual grains need to contain ~0.02–0.04 mg of 1080. In contrast, only the impregnation rates for malted barley (3.2 mg per grain) showed sufficient promise that this product could be considered for further development for use in 'One-shot' rabbit-control programs (poison grains nominally need to contain 4.5 mg 1080). Compared with oats, non-toxic malted and unmalted barley were equally acceptable food items to free-ranging rabbits. The addition of salt (NaCl, 0.9%) did not enhance the consumption of bait (oats and malted barley).1080 was not uniformly distributed throughout the poisoned One-shot oats, with 80% of the active ingredient in the husk, and 20% in the kernel. The size of oat also influenced impregnation rates, with the larger grains containing more 1080. Dehusking of the oats by rabbits (i.e. only the kernel was consumed) occurred in ~84% of cases examined (n = 31 food stations). As little as 6 mm of rainfall resulted in the total loss of detectable amounts of 1080 in One-shot oats collected over 41 days from a standard bait trail laid on sandy soil during summer. The impact of the above on rabbit-control programs could be potentially overcome (partially or wholly) by: the development and inclusion of barley products as bait, the alternation of conventional and One-shot baiting techniques in control programs, the responsible inclusion of a chronic poison (e.g. anticoagulant, pindone) in baiting programs, and ensuring that all poison grains in any bait are of uniform size and contain as close as possible to the nominal amount of active ingredient.
The effects of experimental patch burning and rainfall on small mammals in the Simpson Desert, Queensland
Authors: Letnic Mike
Published: December 2003

Patch-burning is frequently advocated as a management tool to enhance the biodiversity and pasture values of spinifex (Triodia) grasslands. In the northern Simpson Desert, Queensland, pastoralists use fire to reduce the likelihood of broad-scale wildfires and improve pastures for cattle. I conducted a before–after–control–impact experiment to investigate the response of small mammals to the short-term (<1 year) effects of patch-burning between August 1999 and June 2001. The experiment was replicated at three locations subject to differing rainfalls, with two 1-ha study grids remaining unburnt as controls, and two being burnt at each location. The areas burnt ranged from 1 to 3 ha. Dasycercus cristicauda and Pseudomys desertor responded negatively to the fire treatment. Notomys alexis responded positively to the fire treatment in the final trapping session but only at one location. Factors indicative of temporal and spatial variation in rainfall, time and site had a greater effect on the abundance of small mammals than the fire treatment. Heavy rainfalls in 2000 increased seed production and prompted increases in the populations of rodent species and Dasycercus cristicauda. The greatest numbers of captures were made at the sites that received the highest rainfalls. Patch-burning regimes are likely to increase the resilience of 'fire-sensitive' species dependent on dense spinifex by reducing the extent of wildfires.
Levamisole can induce conditioned taste aversion in foxes
Authors: Massei Giovanna , Lyon Alicia , Cowan David P.
Published: December 2003

Conditioned Taste Aversion (CTA) develops when animals associate the taste of a particular food with illness and subsequently avoid consuming that food. We evaluated the potential of two chemicals, thiabendazole and levamisole hydrochloride, to induce CTA to meat in captive foxes (Vulpes vulpes). Foxes were presented for 45 min with thiabendazole or levamisole-treated meat (treatment group) or with untreated meat (control group). In subsequent tests, carried out at 3-week intervals, we tested whether foxes had established an aversion to untreated meat. One or two doses of thiabendazole induced CTA to the test meat in 3 out of 4 foxes. All foxes that had consumed a single portion of levamisole-treated meat avoided eating untreated test meat for the following seven post-treatment tests. The potential of using levamisole-induced CTA as a non-lethal method of manipulating the behaviour of predators is discussed.
The Endogeneity of the Optimum Currency Area Criteria, Intra‐industry Trade, and EMU Enlargement
Authors: Fidrmuc Jarko
Published: December 2003

This article tests the endogeneity hypothesis of optimum currency area (OCA) criteria in a cross‐section of OECD countries in the 1990s. It argues that intraindustry trade induces convergence of business cycles, while no direct relation between business cycles and bilateral trade intensity is found. This finding confirms the OCA endogeneity hypothesis, but it underlines the role of trade specialization. Furthermore, the endogeneity of OCA criteria implies a comparable degree of business cycle harmonization of Central and Eastern European countries with the EU as for the current members in the medium run. (JEL F15, F41)
National Health Insurance and Technology Adoption: Evidence from Taiwan
Authors: Chou Shin‐Yi , Liu Jin‐Tan , Hammitt James K.
Published: December 2003

Generous health‐insurance coverage may encourage hospitals to acquire and employ more advanced medical technologies. The authors examine the effects of Taiwan's 1995 implementation of National Health Insurance on technology adoption, ownership, and use by comparing changes in adoption, ownership, and use rates by private hospitals with changes by public nonteaching and public teaching hospitals. Using random‐effect panel probit and tobit models, the article finds strong empirical evidence that third‐party payment increases the probability of technology adoption, ownership, and use. (JEL H4, I)
The Interplay of Wage and Exchange Rate Policies in Singapore: A Case of Collective Bargaining in Macroeconomic Management
Authors: Wu Ying , Goh Kuang Hui , Lee Boon Keng
Published: December 2003

This article analyzes an optimization model of the policy game between Singapore's National Wage Council and the Monetary Authority of Singapore and further simulates the model over policy rules (Nash game versus non‐Nash game), economic scenarios, and the game players' preference and bargaining power. The results indicate that the exchange rate appreciation and wage growth act as substitutes under the Nash rule of policy responses, whereas they act as complements under the non‐Nash rule. Under the Nash rule, the exchange rate appreciation tends to be procyclical and wage growth countercyclical; union workers' bargaining power relative to employers' strengthens the procyclical appreciation uniformly but reinforces the countercyclical wage growth only when the economy undergoes a downturn. Both the Nash and non‐Nash rules call for more moderate appreciation and more flexible wage adjustments than their actual movements. (JEL E64, E61, F41)
Employment Protections for Older Workers: Do Disability Discrimination Laws Matter?
Authors: Stock Wendy A. , Beegle Kathleen
Published: December 2003

Although age discrimination laws boost employment of older workers, some are exempt from age‐law protection and may be better protected by disability discrimination laws. Disability laws may raise the costs of employing the disabled, however, generating mixed predictions regarding employment effects of protection by both types of laws. This study finds that employment of older disabled workers with the coupled laws is lower than those with age‐law protection only; employment of the younger disabled is higher with the coupled laws. For older disabled workers, earnings of those with the coupled laws are lower than their counterparts with only age‐law protection. (JEL J78, K31, J00)
Regions: An Illusive Concept
Authors: Page Sheila
Published: December 2003

Books reviewed in this article:

Tan, Joseph L.H. (ed.), AFTA in the Changing International Economy

Menon, Jayant, Adjusting Towards AFTA: The Dynamics of Trade in ASEAN

Bora, Bijit and Findlay, Christopher (eds), Regional Integration and the Asia‐Pacific

Lawrence, Robert Z., Regionalism, Multilateralism, and Deeper Integration
Architecture of the Mind
Authors: Newman Geoffrey
Published: December 2003

Margaret Richardson and Maryanne Stevens (eds) John Soane, Architect: Master of Space and Light

Gillian Darley John Soane: An Accidental Romantic

Ptolemy Dean Sir John Soane and the Country Estate
Sublime Marin
Authors: Callan Guy
Published: December 2003

Book reviewed:

Louis Marin. Translated by Catherine Porter, Sublime Poussin
A Special Place/A Learning Space: Museums in the Twenty‐First Century
Authors: Lahav Sylvia
Published: December 2003

Books reviewed in this section:

Charlotte and Peter Fiell, William Morris

Shulamith Behr, Expressionism