bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory of synergy between electron cyclotron and lower hybrid waves
Authors: Dumont R. J. , Giruzzi G.
Published: June 2004

A theoretical study of the improvement of the electron cyclotron current drive (ECCD) efficiency in regimes in which most of the current is driven by lower hybrid (LH) waves is presented. A perturbation technique is employed to solve the adjoint equation and derive the response function including both collisional and LH effects in the limit where the former dominate. An alternative treatment of the problem, involving a numerical solution of the Langevin equations, is proposed to gain insight into the current drive mechanism and to confirm the obtained results. The existence of a cross-effect between the two waves is demonstrated and the conditions for the synergy (i.e., significant enhancement of the ECCD efficiency in the presence of LH power) are identified.
Understanding of electrohydrodynamic conduction pumping phenomenon
Authors: Feng Yinshan , Seyed-Yagoobi Jamal
Published: June 2004

Electrohydrodynamic (EHD) phenomena can be applied to enhance and control mass and heat transfer in both terrestrial and microgravity environments. The emerging EHD conduction pumping technique shows its potential as an active control method of the flow distribution. The EHD conduction pumping is associated with the heterocharge layers of finite thickness in the vicinity of the electrodes, which are based on the process of dissociation of the neutral electrolytic species and recombination of the generated ions. This paper theoretically and experimentally studies the EHD conduction phenomenon in a dielectric liquid. The analytical solutions provide the non-dimensional distributions of electric field and charge density in the vicinity of the electrodes. The characteristic heterocharge layer thickness is also theoretically predicted. Measured pressure heads and current levels are compared with the theoretical results. The EHD conduction pump presented here is capable of electrically driving and controlling the dielectric liquid flow motion in a single-phase loop.
Quantum-shell corrections to Thomas–Fermi–Dirac equation-of-state theory
Authors: Ritchie Burke
Published: June 2004

Quantum-shell corrections are made directly to the finite-temperature Thomas–Fermi–Dirac (TFD) statistical model of the atom by a partition of the electronic density into bound and free parts. The bound part is calculated using analytic basis functions whose parameters are chosen to minimize the energy and pressure. Poisson’s equation is solved for the modified density. The shock Hugoniot is calculated for aluminum. Shell effects characteristic of quantum self-consistent field (QSCF) models are fully captured by the present theory. The use of a quantum decription of the bound density removes the physically spurious singularity at the origin which is present in TFD theory.
Størmer regions for axisymmetric magnetic multipole fields
Authors: Shebalin John V.
Published: June 2004

The motion of a single charged particle in the space outside of a compact region of steady currents is investigated. The charged particle is assumed to produce negligible electromagnetic radiation, so that its energy is conserved. The source of the magnetic field is represented as a point multipole. After a general description, attention is focused on magnetic fields with axial symmetry. Lagrangian dynamical theory is utilized to identify constants of the motion as well as the equations of motion themselves. In particular, the energy and the canonical angular momentum conjugate to the azimuthal angle are conserved for axial symmetry. Following the precedent of some authors, and for brevity, the constant canonical angular momentum conjugate to the azimuthal angle will be called Størmer’s integral. In the present work, the magnetic vector potential equivalent to a given spherical harmonic scalar potential is also found. The qualitative method of Størmer is then used to examine charged particle motion in axisymmetric multipole fields of all orders, and while the treatment is fully relativistic, it also encompasses nonrelativistic motion. This qualitative method divides the configuration space of the charged particle into sets in which motion is either forbidden or allowed, i.e., it permits a topological examination of dynamical motion. The results obtained here allow for the determination of trapped-particle regions around those astrophysical objects and spacecraft plasma propulsion systems that have an associated axisymmetric magnetic field described by a multipole of given order.
Kinetic effects on the parametric decays of circularly polarized electromagnetic waves in a relativistic pair plasma
Authors: Muñoz V.
Published: June 2004

Parametric decays of a circularly polarized electromagnetic wave in an electron–positron plasma are studied. Relativistic effects on the particle motion in the wave field are included. The analysis is based on the Vlasov equation in order to account for kinetic effects. There are two types of decays: one in which the pump wave decays into two electromagnetic waves, and the other where the pump wave decays into electromagnetic waves and electroacoustic pseudomodes. These decays have been found in the weakly relativistic regime for both the fluid and the kinetic theory, even though the electroacoustic pseudomodes satisfy ω/kvth∼1, and therefore, they are strongly Landau damped. In this work the dispersion relation for the parametric decays in the relativistic regime is calculated, and it is studied numerically assuming the equilibrium distribution function is a one-dimensional Maxwell–Jüttner distribution. Results are compared with the weakly relativistic case.
Application of stereoscopic particle image velocimetry to studies of transport in a dusty (complex) plasma
Authors: Thomas Edward , Williams Jeremiah D. , Silver Jennifer
Published: June 2004

Over the past 5 years, two-dimensional particle image velocimetry (PIV) techniques [E. Thomas, Jr., Phys. Plasmas 6, 2672 (1999)] have been used to obtain detailed measurements of microparticle transport in dusty plasmas. This Letter reports on an extension of these techniques to a three-dimensional velocity vector measurement approach using stereoscopic PIV. Initial measurements using the stereoscopic PIV diagnostic are presented.
The loss of stability of surface superconductivity
Authors: Almog Y.
Published: June 2004

The Ginzburg–Landau equations in a half-plane are considered in the large κ limit. We look at the reduced set of equations obtained in that limit. It is proved that the one-dimensional solution presented by Pan [Commun. Math. Phys. 228, 327 (2002)] undergoes a bifurcation for an infinite number of applied magnetic field values which are lower than HC2. We also prove that each bifurcating mode is energetically preferable to the one-dimensional surface superconductivity solution, and thus, prove that the surface superconductivity becomes unstable for applied fields which are lower than HC2
Low frequency modes in strongly coupled magnetized dusty plasmas
Authors: Xie Bai-Song , Chen Yan-Ping
Published: June 2004

Low frequency modes in strongly coupled magnetized dusty plasmas are investigated based on the generalized hydrodynamic model for dust particles. A longitudinal hybrid-like mode in the perpendicular direction exists with weak damping. Especially, a peculiar transverse shear mode is found in the parallel direction due to strong coupling in the magnetized dusty plasma. Its group velocity is proportional to the wave vector, analogous to a torsional vibration mode in a solid.
Construction and uniqueness of the C*-Weyl algebra over a general pre-symplectic space
Authors: Binz Ernst , Honegger Reinhard , Rieckers Alfred
Published: June 2004

A systematic approach to the C*-Weyl algebra W(E,σ) over a possibly degenerate pre-symplectic form σ on a real vector space E of possibly infinite dimension is elaborated in an almost self-contained manner. The construction is based on the theory of Kolmogorov decompositions for σ-positive-definite functions on involutive semigroups and their associated projective unitary group representations. The σ-positive-definite functions provide also the C*-norm of W(E,σ), the latter being shown to be *-isomorphic to the twisted group C*-algebra of the discrete vector group E. The connections to related constructions are indicated. The treatment of the fundamental symmetries is outlined for arbitrary pre-symplectic σ. The construction method is especially applied to the trivial symplectic form σ=0, leading to the commutative Weyl algebra over E, which is shown to be isomorphic to the C*-algebra of the almost periodic continuous function on the topological dual Eτ′ of E with respect to an arbitrary locally convex Hausdorff topology τ on E. It is demonstrated that the almost periodic compactification aEτ′ of Eτ′ is independent of the chosen locally convex τ on E, and that aEτ′ is continuously group isomorphic to the character group Ê of E. Applications of the results to the procedures of strict and continuous deformation quantizations are mentioned in the outlook.
The bundles of algebraic and Dirac–Hestenes spinor fields
Authors: Mosna Ricardo A. , Rodrigues Waldyr A.
Published: June 2004

Our main objective in this paper is to clarify the ontology of Dirac–Hestenes spinor fields (DHSF) and its relationship with even multivector fields, on a Riemann–Cartan spacetime (RCST) M=(M,g,∇,τg,↑) admitting a spin structure, and to give a mathematically rigorous derivation of the so-called Dirac–Hestenes equation (DHE) in the case where 𝔐 is a Lorentzian spacetime (the general case when 𝔐 is a RCST will be discussed in another publication). To this aim we introduce the Clifford bundle of multivector fields (Cl(M,g)) and the left (ClSpin1,3el(M)) and right (ClSpin1,3er(M)) spin-Clifford bundles on the spin manifold (M,g). The relation between left ideal algebraic spinor fields (LIASF) and Dirac–Hestenes spinor fields (both fields are sections of ClSpin1,3el(M)) is clarified. We study in detail the theory of covariant derivatives of Clifford fields as well as that of left and right spin-Clifford fields. A consistent Dirac equation for a DHSF Ψ∈sec ClSpin1,3el(M) (denoted DECll) on a Lorentzian spacetime is found. We also obtain a representation of the DECll in the Clifford bundle Cl(M,g). It is such equation that we call the DHE and it is satisfied by Clifford fields ψⅪ∈sec Cl(M,g). This means that to each DHSF Ψ∈sec ClSpin1,3el(M) and spin frame Ⅺ∈sec PSpin1,3e(M), there is a well-defined sum of even multivector fields ψⅪ∈sec Cl(M,g) (EMFS) associated with Ψ. Such an EMFS is called a representative of the DHSF on the given spin frame. And, of course, such a EMFS (the representative of the DHSF) is not a spinor field. With this crucial distinction between a DHSF and its representatives on the Clifford bundle, we provide a consistent theory for the covariant derivatives of Clifford and spinor fields of all kinds. We emphasize that the DECll and the DHE, although related, are equations of different mathematical natures. We study also the local Lorentz invariance and the electromagnetic gauge invariance and show that only for the DHE such transformations are of the same mathematical nature, thus suggesting a possible link between them.
Computer simulations of relativistic whistler-mode wave–particle interactions
Authors: Omura Yoshiharu , Summers Danny
Published: June 2004

Whistler-mode wave–electron interactions constitute an important physical mechanism in the Earth’s magnetosphere and the radiation belts of the magnetized planets. From linear theory, an analytical result for the growth rate of electromagnetic R-mode (whistler-mode) waves in a relativistic bi-Maxwellian plasma with given temperature anisotropy is obtained. In order to test the linear theory, a one-dimensional self-consistent electromagnetic particle simulation is performed with a newly developed fully relativistic code. A major background component of isotropic cold electrons and a minor component of anisotropic hot electrons in a uniform magnetic field are assumed. Driven by the temperature anisotropy of the hot relativistic electrons, the whistler-mode waves grow initially linearly, and then nonlinearly to a level at which saturation takes place. Saturation occurs due to a combination of nonlinear trapping of resonant electrons and quasilinear relaxation of the temperature anisotropy. The initial wave growth rate obtained from the particle simulation agrees well with the growth rate predicted from linear theory. In order to reduce electrostatic fluctuations and achieve accuracy in the simulation, a large number of superparticles must be used.
Mobility and interactions of weakly nonwetting droplets
Authors: Pismen Len M. , Pomeau Yves
Published: June 2004

Lubrication equations based on diffuse interface theory are applied to description of slow motion and interaction of droplets on solid support. For the case of quasistationary motion of a weakly nonwetting fluid, we derive integral relations reducing the problem to computation of ratios of applicable “thermodynamic forces” to a dissipative integral characterizing an individual droplet. This allows us to describe the droplet motion without computing explicitly the distortion of their shape. Explicit computations are carried out for a droplet sliding on an inclined plane, and for an ensemble of droplets interacting through the precursor layer.
Initial Model Catalogue for Galaxy Evolution
Authors: Nakasato Naohito
Published: June 2004

We have computed full hydrochemodynamical evolution for 150 initial models of protogalaxies with our chemodynamical SPH code named GENSO. Various parameters for all models are identical except for a seed for a random number generator. In other words, all models have similar global properties but have the different merging history that leads to a different evolution in each model. Results of the series of computations have two main applications. Firstly, we have an initial model catalogue for subsequent modelling of galaxy evolution. Since the resulting evolution depends strongly on the initial phase of the particle distribution, it is crucial to find a suitable initial model when we model a specific real galaxy in the Universe, notably the Milky Way in our case. We will make a precise chemical and dynamical model of the Milky Way out of 150 models in our initial model catalogue. Secondly, we can obtain a large variety of global histories of physical values such as star formation, metallicity in the ISM and stellar components, and Type II and Ia supernova rates. For example, the resulting total star formation history shows the peak at a high redshift z ∼ 6 and the peak value is ∼280 M⊙ yr–1 Mpc–3. Also, the Type Ia rate obtained has a peak at z ∼ 3.5. All of our results and model catalogue are publicly available from our website for those who wish to model galaxy evolution.
The Andromeda Stream
Authors: Lewis G. F. , Ibata R. A. , Chapman S. C. , Ferguson A. M. N. , McConnachie A. W. , Irwin M. J. , Tanvir N.
Published: June 2004

The existence of a stream of tidally stripped stars from the Sagittarius dwarf galaxy demonstrates that the Milky Way is still in the process of accreting mass. More recently, an extensive stream of stars has been uncovered in the halo of the Andromeda galaxy (M31), revealing that it too is cannibalising a small companion. This paper reports the recent observations of this stream, determining its spatial and kinematic properties, and tracing its three-dimensional structure, as well as describing future observations and what we may learn about the Andromeda galaxy from this giant tidal stream.
Star Clusters and Galactic Chemodynamics: Implosive Formation of Super Star Clusters
Authors: Bekki Kenji
Published: June 2004

We numerically investigate dynamical and chemical properties of star clusters (open and globular clusters, and ‘super star clusters’, SSC) formed in interacting/merging galaxies. The investigation is two-fold: (a) large-scale (100 pc–100 kpc) SPH simulations on density and temperature evolution of gas in interacting/merging galaxies and (b) small-scale simulations on the effects of the high gas pressure of the ISM on the evolution of molecular clouds. We find that the pressure of ISM in merging galaxies can become higher than the internal pressure of GMCs (∼105kB K cm–3), in particular, in the tidal tails or the central regions of mergers. We also find that GMCs can collapse to form SSCs within an order of 107 yr due to the strong compression by the high-pressure ISM in mergers.
Substructure in the Galactic Halo
Authors: Majewski Steven R.
Published: June 2004

Giant stars make particularly useful tracer stars for halo substructure because they are very bright and very common. I discuss several projects that use giant-star tracers to search the Galactic halo for tidal debris from known Galactic satellites, including that from the Sagittarius dwarf galaxy, and to search for tidal debris features from former, now destroyed satellites. Several cross-sections of the halo reveal it to be networked with extended, coherent substructures, indicating that it is likely to be predominantly made up of accreted satellites.
Chemodynamical Evolution of Elliptical Galaxies: Metallicity Gradients and Scaling Relations
Authors: Kobayashi Chiaki
Published: June 2004

We simulate the chemodynamical evolution of a hundred elliptical galaxies using our GRAPE-SPH code, and succeed in reproducing the radial metallicity gradients and the global scaling relations such as the fundamental plane. These observations cannot be explained by either monolithic collapse or by major merger alone. Rather it requires a model in which both formation processes arise, such as the present CDM scheme.
Improved germination of the Australian natives: Hibbertia commutata, Hibbertia amplexicaulis (Dilleniaceae), Chameascilla corymbosa (Liliaceae), and Leucopogon nutans (Epacridaceae)
Authors: Allan Sally M. , Adkins Steve W. , Preston Christine A. , Bellairs Sean M.
Published: June 2004

Hibbertia commutata (Steudel), H. amplexicaulis (Steudel), Chameascilla corymbosa [(R.Br.) F.Muell. Ex Benth.] and Leucopogon nutans (E.Pritzel) are four Australian species that are difficult to germinate during mine-site rehabilitation. Laboratory germination trails were conducted to identify dormancy mechanisms and to improve germination response. Treatments applied to all species included scarification and scarification followed by soaking seeds in smoke water (1, 5 or 10%) or gibberellic acid solution (50, 200 or 1000 μM). Additional treatments with kinetin solution (50, 200 or 1000 μM) and smoke water (50 or 100%) were applied to scarified or unscarified seeds of C. corymbosa. Thermal-shock treatment was applied to L. nutans fruit, some of which were subsequently scarified and subjected to both smoke water (10%) and gibberellic-acid solution (1000 μM). Significant germination increases were obtained by using dormancy-breaking treatments on H. commutata (12.8 to 76.0%), H. amplexicaulis (6.8 to 55.1%) and C. corymbosa (48.5 to 86.4%). Scarification alone increased germination of both Hibbertia species, suggesting that these species display a physical seed coat-imposed dormancy mechanism. Germination of H. amplexicaulis was further increased by the application of gibberellic-acid solution, indicating a possible embryo-imposed dormancy mechanism. Scarification followed by the application of smoke water produced the highest germination response for C. corymbosa seeds. Scarification alone did not significantly increase germination, inferring the existence of a smoke-responsive embryo dormancy mechanism. Seeds of L.�nutans, although viable, failed to germinate and are thought to display complex seed coat- and embryo-imposed dormancy mechanisms.
Effects of fire history on the structure and floristic composition of woody vegetation around Kalumburu, North Kimberley, Australia: a landscape-scale natural experiment
Authors: Vigilante T. , Bowman D. M. J. S.
Published: June 2004

Indigenous landscape burning is practiced around remote communities in the Kimberleys but has been replaced by wildfires across uninhabited areas. A landscape-scale natural experiment was established to investigate the effects of these different fire histories (derived from a 10-year Landsat remote-sensing sequence) on the floristic structure and composition of woody vegetation within and among three of the major vegetation types on three landscape types (sandplain, sandstone and volcanics) near Kalumburu in the North Kimberley bioregion.Substrate factors determine vegetation and associated fire patterns within the landscape such that each landscape type needs to be examined independently. Basalt soils are dominated by an open savanna and tend to have very high fire frequencies. Basalt vegetation showed few significant response variables to fire-history parameters. The total density of woody stems showed no significant relationship to fire-history variables, regardless of size class. The 0–2.0-m size class of Erythrophleum chlorostachys (F.Muell.) Baillon showed significant (P < 0.005) responses to the various interactions involving all three fire-history variables, indicating that seedling density is sensitive to fire.Sandplain is dominated by open woodland, with relatively low fire frequency. Total stem density, shrub density and the densities of Grevillea agrifolia Cunn. Ex R.Br., Canthium sp. A and Stenocarpus cunninghamii R.Br. showed strong positive (P < 0.005) relationships with the total number of fire-free months. In sandstone, the density of all woody stems, acacias and a range of mid-storey trees showed significant positive relationships with the total number of fire-free months. Other species showed strong relationships with the number of late dry season fires. Vegetation thickening was evident in sand environments through the accumulation of woody stems in fire-free years and in sandstone through the promotion of 'fireweeds' such as Acacia gonocarpa F.Muell. after fire events.Mid-storey tree species capable of resprouting after fire showed some evidence of structural suppression in response to frequent fire events, including Planchonia careya (F.Muell.) Knuth, Persoonia falcata R.Br. and Buchanania obovata Engl.Results are discussed in the context of indigenous landscape burning and biodiversity conservation.
Estrogen receptor β regulates epithelial cellular differentiation in the mouse ventral prostate
Authors: Imamov Otabek , Morani Andrea , Shim Gil-Jin , Omoto Yoko , Thulin-Andersson Christina , Warner Margaret , Gustafsson Jan-Åke
Published: June 2004

We have previously reported epithelial cellular hyperplasia in ventral prostates (VP) of mice lacking estrogen receptor β (ERβ). To investigate the causes of this phenomenon, we measured cellular proliferation and apoptosis in VP of ERβ
-/-
and WT mice. With BrdUrd labeling, the number of proliferating cells was 3.6-fold higher in ERβ
-/-
mice. There was also a decrease in apoptosis as measured by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay and an increase in expression of the anti-apoptotic bcl-2. The state of differentiation of the epithelial cells of the VP was studied by immunohistochemical staining, Western blotting, and fluorescence-activated cell sorting (FACS). In ERβ
-/-
mouse VP, the number of p63-positive cells (basal phenotype) was 2.6-fold higher, and expression level of cytokeratin (CK) 8, a luminal cell marker, was lower. FACS analysis with p63 showed that in WT mice the ratio of basal to intermediate/luminal cell populations expressing p63 was 1:2.5, whereas in ERβ
-/-
mice it was 1:9. The expression of basal/intermediate marker CK 19 in three FACS areas, g1, g2, and g3, gated according to cellular size and granularity, was 1:0.6:2 in WT and 1:4:6.7 in ERβ
-/-
mice, showing a shift of CK 19-positive cells toward a cell population of intermediate size and granularity. We conclude that, in ERβ
-/-
mouse VP, there is increased epithelial proliferation, decreased apoptosis, and accumulation of incompletely differentiated cells in an intermediate pool. The continued proliferation of intermediate cells leads to the prostatic epithelial hyperplasia observed in the absence of ERβ signaling.
Selection–subtraction approach (SSA): A universal genetic screening technique that enables negative selection
Authors: Singhi Aatur D. , Kondratov Roman V. , Neznanov Nickolay , Chernov Mikhail V. , Gudkov Andrei V.
Published: June 2004

Screening of expression libraries for bioactive clones that modulate the growth of mammalian cells has been limited largely to positive selections incapable of revealing growth suppressive or lethal genetic elements. We have developed a technique, selection–subtraction approach (SSA), that allows growth-modulating clones to be isolated based on alterations in their relative abundance in growing cell populations that have been transduced with an expression library. SSA utilizes tagged retroviral libraries in bacteriophage λ vectors (retrophages). Nylon prints from retrophage libraries are used to determine the relative abundance of tags in library-transduced cells to identify biological activity of individual clones. Applications of SSA for gene discovery, target discovery, and generation of mutant proteins have been demonstrated, by using p53 and ataxia telangiectasia mutated (ATM) as models to isolate growth inhibitory proteins, peptides and antisense RNAs, and temperature-sensitive mutant proteins.
Cortagine, a specific agonist of corticotropin-releasing factor receptor subtype 1, is anxiogenic and antidepressive in the mouse model
Authors: Tezval Hossein , Jahn Olaf , Todorovic Cedomir , Sasse Astrid , Eckart Klaus , Spiess Joachim
Published: June 2004

Two subtypes of the corticotropin-releasing factor (CRF) receptor, CRF
1
and CRF
2
, differentially modulate brain functions such as anxiety and memory. To facilitate the analysis of their differential involvement, we developed a CRF
1
-specific peptidic agonist by synthesis of chimeric peptides derived from human/rat CRF, ovine CRF (oCRF), and sauvagine (Svg). High affinity to the CRF-binding protein was prevented by introduction of glutamic acid in the binding site of the ligand. The resulting chimeric peptide, [Glu
21
,Ala
40
][Svg
1–12
]×[human/rat CRF
14–30
]×[Svg
30–40
], named cortagine, was analyzed pharmacologically in cell culture by using human embryonic kidney-293 cells transfected with cDNA coding for CRF
1
or CRF
2
, in autoradiographic experiments, and in behavior experiments using male C57BL/6J mice for its modulatory action on anxiety- and depression-like behaviors with the elevated plus-maze test and the forced swim test (FST), respectively. We observed that cortagine was more selective than oCRF, frequently used as CRF
1
-specific agonist, in stimulating the transfected cells to release cAMP. Cortagine's specificity was demonstrated in autoradiographic experiments by its selective binding to CRF
1
of brain sections of the mouse. After injection into the brain ventricles, it enhanced anxiety-like behavior on the elevated plus-maze at a lower dose than oCRF. Whereas at high doses, oCRF injected into the lateral intermediate septum containing predominantly CRF
2
increased anxiety-like behavior as CRF
2
-specific agonists do, cortagine did not. In contrast to its anxiogenic actions, cortagine reduced significantly the immobility time in the FST as described for antidepressive drugs. Thus, cortagine combines anxiogenic properties with antidepressive effects in the FST.
The symmetric eigenvalue complementarity problem
Authors: Queiroz Marcelo , Júdice Joaquim , Humes Carlos
Published: June 2004

In this paper the Eigenvalue Complementarity Problem (EiCP) with real symmetric matrices is addressed. It is shown that the symmetric (EiCP) is equivalent to finding an equilibrium solution of a differentiable optimization problem in a compact set. A necessary and sufficient condition for solvability is obtained which, when verified, gives a convenient starting point for any gradient-ascent local optimization method to converge to a solution of the (EiCP). It is further shown that similar results apply to the Symmetric Generalized Eigenvalue Complementarity Problem (GEiCP). Computational tests show that these reformulations improve the speed and robustness of the solution methods.
A new approximation technique for div-curl systems
Authors: Bramble James , Pasciak Joseph
Published: June 2004

In this paper, we describe an approximation technique for div-curl systems based in

(

L
2

(
Ω

)
3

)

(L^2(\Omega )^3)

where

Ω
\Omega

is a domain in

R

3

\mathbb {R}^3

. We formulate this problem as a general variational problem with different test and trial spaces. The analysis requires the verification of an appropriate inf-sup condition. This results in a very weak formulation where the solution space is

(

L
2

(
Ω
)

)
3

(L^2(\Omega ))^3

and the data reside in various negative norm spaces. Subsequently, we consider finite element approximations based on this weak formulation. The main approach of this paper involves the development of “stable pairs" of discrete test and trial spaces. With this approach, we enlarge the test space so that the discrete inf-sup condition holds and we use a negative-norm least-squares formulation to reduce to a uniquely solvable linear system. This leads to optimal order estimates for problems with minimal regularity which is important since it is possible to construct magnetostatic field problems whose solutions have low Sobolev regularity (e.g.,

(

H
s

(
Ω
)

)
3

(H^s(\Omega ))^3

with

0
>
s
>
1

/

2

0> s> 1/2

). The resulting algebraic equations are symmetric, positive definite and well conditioned. A second approach using a smaller test space which adds terms to the form for stabilization will also be mentioned. Some numerical results are also presented.
On the error estimates for the rotational pressure-correction projection methods
Authors: Guermond J. , Shen Jie
Published: June 2004

In this paper we study the rotational form of the pressure-correction method that was proposed by Timmermans, Minev, and Van De Vosse. We show that the rotational form of the algorithm provides better accuracy in terms of the

H
1

H^1

-norm of the velocity and of the

L
2

L^2

-norm of the pressure than the standard form.
Obstacles to the torsion-subgroup attack on the decision Diffie-Hellman Problem
Authors: Koblitz Neal , Menezes Alfred
Published: June 2004

Cheng and Uchiyama show that if one is given an elliptic curve, depending on a prime

p
p

, that is defined over a number field and has certain properties, then one can solve the Decision Diffie-Hellman Problem (DDHP) in

F

p
∗

\mathbb {F}_p^*

in polynomial time. We show that it is unlikely that an elliptic curve with the desired properties exists.
Food safety, environmental improvement and economic efficiency in The Netherlands
Authors: Reijnders Lucas
Published: June 2004

Food safety is a major public concern in The Netherlands following mishaps in the animal feed industry. These were associated with the handling of wastes. Financial gains to those responsible have been outweighed by economic losses. Other safety risks include the presence of infectious bacteria and viruses, mycotoxins, additives, substances derived from packaging and conversion products originating in food processing. Present risks and presumable trends in food safety are highlighted. Substantial improvement of food safety is possible. In part, such improvement is linked to environmental improvement, but there are also cases in which reductions in risk may increase the environmental burden of food supply. Improvement of food safety often entails increased costs. Major retailers and food producers apparently feel that consumers are willing to pay for substantially improved food safety. There are also health related financial benefits associated with reduced food risk.
Offshore teaching and learning: an exploratory Singaporean study
Authors: Richards Noel , Lee Ross Darren
Published: June 2004

This study is the first of three which discuss and investigate the provision and progress of undergraduate business degree programs to an educational provider in Singapore. Building on the work of Hofstede and Gibb, it shows how both models may be integrated for a flexible and enterprising approach to teaching and learning in a cross‐cultural context. Drawing on the authors’ recent experiences at the Washington Business School in Singapore, the paper advocates that this approach will yield greater benefits than current methods. It concludes that an effective enterprising approach to teaching and learning is possible, provided a number of key cultural matters are addressed. Further study is recommended to substantiate the propositions of the present paper to evaluate the outcomes of the new approach in the Singaporean cultural/educational context. It is expected that these studies will benefit tertiary educators operating or contemplating entry into Asian markets.
It's time to get to first principles in service design
Authors: Chase Richard B.
Published: June 2004

Current approaches to service design and service quality have provided second order principles that fail to account for underlying cognitive processes of customers in service encounters. It is proposed that behavioral science research should be used to address this shortcoming, and five “first order” principles are presented based upon a review of the behavioral science literature.
Why customers stay: reasons and consequences of inertia in financial services
Authors: White Lesley , Yanamandram Venkat
Published: June 2004

This research investigated inertia in a financial‐services context, with particular focus on the reasons for consumers’ dissatisfaction and inert behaviour, and studied customers’ complaining behaviours and past and future inertia. The study utilised a two‐part methodology, including both qualitative and quantitative research. A total of 20 in‐depth interviews provided the preliminary data required for developing a questionnaire that was subsequently completed by 410 respondents. Determinants of dissatisfaction included the number and size of account fees, whilst determinants of inertia were the perception of similarity between financial institutions and the complexity, costs and time inherent in switching. Factors differentiating future inertia and future active customers included the type of account, length of time the account had been held, membership of a number of financial institutions, income and level of consideration given to changing financial institution.
Reconceptualizing customer perceived value: the value of time and place
Authors: Heinonen Kristina
Published: June 2004

Considering the empowered customer interacting with technology‐based self‐services, temporal and spatial access can be argued to influence service delivery. However, service management models have not considered the value of the service delivery at various locations and time frames not controlled by the service provider. Consequently, by arguing that time and location are explicit value dimensions, this paper investigates the importance of time and location and contrasts them to traditional value dimensions. A conceptual model of customer perceived value is proposed and empirically investigated. By linking value and quality models, customer perceived value is conceptualized as a function of benefit and sacrifice of technical, functional, temporal and spatial value dimensions. The empirical findings indicate that time and location are perceived as important value dimensions and that they are even more important dimensions than outcome and process elements. Theoretical and practical implications of the findings are discussed.
ICT: the creation of value and differentiation in services
Authors: Meyronin Benoît
Published: June 2004

This paper raises the question of the impact that the increasing use of information and communication technologies (ICT) has on the process of creating value and the differentiation in service activities. We shall develop the idea that electronic intermediation tends to “impoverish” service relations, insomuch as the technological interface can by no means replace the wealth of human interactions on which the creation of value and the differentiation of services are based. So it is mainly a theoretical contribution based on American and French academic works in the field of services marketing management.
Customer involvement in new service development: a conversational approach
Authors: Lundkvist Anders , Yakhlef Ali
Published: June 2004

The expression “customer involvement” is finding increasing popularity with popular as well as academic marketing texts. Within the evolving research, customer involvement is cast in an information‐processing mould that tends to reduce it to the mere transfer of information from where it exists (customers) to where it is dearly needed (the firm). Customers' active participation is accounted for in economic psychological (contract) terms. Drawing on case study material gleaned from an organisation that adopted a customer involvement strategy, the present paper suggests a conversational approach that regards customers' active participation and involvement in terms of conversational exchanges between customers during which new ideas are jointly co‐created and commitment to action is established. Conversation is not only the fostering ground for new ideas and knowledge, but also the source of social agency. Some theoretical and practical implications of the conversation‐based customer‐firm interface for involving customers are discussed.
Matching management tools and techniques with management challenges
Authors: Cullen John , O’Connor Marion , Mangan John
Published: June 2004

The authors compare findings from two studies conducted in an Irish context: a survey of the usage and utilization of management tools and techniques, and a survey of the top challenges facing managers. Although there were some cases where the utilization of the tools and techniques appeared to match the challenges facing the managers, in general this was not the case. The article concludes that rationales for investing in management tools need to be explored in greater detail in order that they might better meet challenges managers face.
Perception of US branded apparel in Shanghai
Authors: Delong Marilyn , Bao Mingxin , Wu Juanjuan , Chao Huang , Li Meng
Published: June 2004

This study focuses on perceptions of registered brands sold in Shanghai. Brand identity has been studied in Western settings; this study expands understanding of brand identity from a Chinese perspective. Chinese shoppers in Shanghai shopping malls were asked to compare US and Chinese brands in a survey about their perceptions of product attributes, brand identification and store environment. In the analysis of data, US brands were evaluated more positively than Chinese on attributes of design innovation, workmanship, brand image, service, and display of products, while Chinese brands received more positive marks on fit and price satisfaction. Low brand loyalty among the Chinese shoppers meant that brand image and competition among brands are keen. To remain competitive, US companies which plan to increase their market in China need to pay attention to product quality and how brand identity is interpreted within Chinese culture.
A comparative study on new retailing outlets in the Shanghai apparel market
Authors: Li Jun , Wang Yunyi , Cassill Nancy L.
Published: June 2004

After China's accession to the WTO, different formats of retailing outlets have emerged and competition within China's apparel retail market has become keener. This paper presents a comparison research on four influential retailing outlets in the current Shanghai apparel retail market: upscale shopping centers, modern shopping malls, joint discount superstores (joint ventures with foreign retail giants), and manufacturers' wholly‐owned flagship stores (factory outlets). Corresponding to each retailing outlet, Plaza 66, Grand‐Gateway Mall, Carrefour Store in Quyang Road, and Youngor Flagship Store in Nanjing Road are studied, with an investigation of apparel brands covered by each. The results identify the four retailing outlets' characteristics, and future prospects in the Chinese apparel retail market are discussed.
Envisioning development
Authors: Dealtry Richard
Published: June 2004

This paper focuses on an important innovative development in new generation corporate university management. It addresses the thematic area of visual learning that is captured in the term “The Art of Minds‐eye Management”. It reflects upon experiences with groups of managers in enhancing perceptive competencies using visual awareness learning systems. The envisioning medium being reviewed and explored takes the form of narrative imagery. This is a form of quantitative and qualitative envisioning which is currently being applied by groups of managers in many different formats to articulate and add new levels of learning and value to developmental themes. This paper reflects upon the mediocrity of traditional flatland representations of classic management concepts and models and explores the potential for delimiting conceptual design and the use of pictorial display of data and information as a means of communication, managing personal performance and accelerating organisational development.
Is fourth generation mobile nirvana or … nothing?
Authors: Forge Simon
Published: June 2004

So far fourth generation (4G) has not been well defined technically, functionally or commercially despite conceptual research having been quietly under way since 1998. But as we have not fully rolled out and digested 2.5G, let alone 3G, why on earth should we be interested in a still further mobile technology? And how will WiFi, WiMAX and existing networks figure in all of this? The answer is that 4G will fundamentally advance the way we use mobile and existing networks and repair the problems of 3G. If allowed to, 4G can take us from radio technologies and concepts of the 1920s into the next era of radio communications using “open spectrum”. And 4G may be able to answer many cost and technical problems of the earlier mobile systems. Once its technical blueprint is worked out, 4G faces enormous challenges, far more than the technical, in commercial/political battles with what it could replace. We examine its challenges here, also considering regulatory policy, which would require that the mobile element is seen as only one of at least six components. The different scenarios for its early development are also briefly reviewed.
Disturbing post‐operative symptoms are not reduced by prophylactic antiemetic treatment in patients at high risk of post‐operative nausea and vomiting
Authors: Alkaissi A. , Gunnarsson H. , Johnsson V. , Evertsson K. , Ofenbartl L. , Kalman S.
Published: June 2004

Background:  To give prophylactics or timely treatment for post‐operative nausea and vomiting (PONV) is the question. We compared the intensity and number of disturbing post‐operative symptoms (i.e. pain, PONV, headache, fatigue, etc.) after prophylactic antiemetic treatment in a group of patients with >30% risk for post‐operative vomiting.

Methods:  Four hundred and ninety‐five patients, from three hospitals, planned for gynaecological surgery were randomized double blind. They were given granisetron 3 mg, droperidol 1.25 mg or no prophylactic antiemetic. Post‐operative symptoms were followed for 24 h using a questionnaire. Symptoms were analyzed both according to their intensity and in a dichotomous fashion.

Results:  The intensity of different symptoms differed depending on whether droperidol, granisetron or no antiemetic had been given (P = 0.005) but the overall incidence of moderate to very severe symptoms was similar in all groups. No group fared better in general. The total number of symptoms was higher in the groups given prophylactic treatment (P < 0.05). The relative risk reduction for PONV with granisetron or droperidol prophylaxis was 27%[95% confidence interval (CI) 8–43] and 22% (2–38), respectively. The NNT (number needed to treat) for granisetron (0–24 h) was 7 and for droperidol 8. The NNH (number needed to harm) (0–24 h) for headache and visual disturbances was 6 and 13 (NS) for granisteron and, 50 (NS) and 6 for droperidol.

Conclusion:  The intensity of symptoms or the total number of disturbing symptoms did not decrease after prophylactic antiemetic treatment in a group of patients, but the profile of disturbing symptoms changed. The relevance of post‐operative symptoms in terms of patients' well‐being needs to be addressed.
Porcine surfactant (Curosurf) for acute respiratory failure after near‐drowning in 12 year old
Authors: Onarheim H. , Vik V.
Published: June 2004

This case report describes rapid and persistent improvement after one single dose of porcine surfactant (Curosurf®) 0.5 ml/kg−1 (40 mg/kg) intratracheally for adult respiratory distress syndrome (ARDS) with severe oxygenation failure 8 h after freshwater near‐drowning in a 12‐year‐old girl.
Isoflurane applied during ischemia enhances intracellular calcium accumulation in ventricular myocytes in part by reactive oxygen species
Authors: Dworschak M. , Breukelmann D. , Hannon J. D.
Published: June 2004

Background:  Isoflurane applied before myocardial ischemia has a beneficial preconditioning effect which involves generation of reactive oxygen species (ROS); ROS, however, have been implicated in critical cytosolic calcium ([Ca2+]i) overload during ischemia. We therefore investigated isoflurane's effects on intracellular Ca2+ handling in ischemic ventricular myocytes and the association with ROS.

Methods:  Simulated ischemia was induced in electrically stimulated rat ventricular myocytes for 30 min (ischemia). Isoflurane‐treated cells were additionally exposed to 1MAC of isoflurane (ischemia + iso). To determine the contribution of ROS to Ca2+ homeostasis during ischemia in both groups, the intracellular ROS scavenger, N‐mercaptopropionylglycine (MPG), was added to the superfusion buffer. The fluorescent ratiometric Ca2+ dye fura‐2 was employed to determine [Ca2+]i.

Results:  Resting and peak [Ca2+]i increased in the ischemia and the ischemia + iso group. However, Ca2+ accumulation was most prominent in isoflurane‐treated cardiomyocytes (P < 0.05) and could be mitigated by MPG in both groups (P < 0.001). Isoflurane also decreased the rate constant of the Ca2+ transient decline but did not further diminish the amplitude of the transient during ischemia.

Conclusion:  Isoflurane when applied during ischemia appears to worsen [Ca2+]i overload, which is caused by impeding Ca2+ clearance. As MPG mitigated the increase in [Ca2+]i, isoflurane seems to enhance ROS‐mediated effects on intracellular Ca2+ handling in cellular ischemia.