bluuebunny/crossref_metadata_2025 huggingface dataset:
Transitory response of confined polymer films subjected to oscillatory shear
Authors: Baljon Arlette R. C.
Published: November 2004

Molecular-dynamics simulations were used to study the response of a nanometer thin polymer film to oscillatory shear. Several types of response occur, depending on the amplitude of the shear. At low amplitude, the film deforms elastically. At intermediate ones it deforms plastically. Short-range stress-induced structured crystalline domains occur. This flexible elastic state is very dynamic. The crystalline domains oscillate with the applied stress. In the course of repeated cycling, they slowly increase in size. These mesoscopic domains may account for experimentally observed memory behavior. Ultra-thin polymer films typically possess relaxation times that are orders of magnitudes larger than those of the individual polymers. When oscillated at even higher amplitude, stick-slip is observed. In our constant pressure simulations, the film yields when wall spacing is increased to a value at which the polymer segments can smoothly rearrange and hence relax the internal stress.
Quantum effect on the internal proton transfer and structural fluctuation in the H5+ cluster
Authors: Ohta Yasuhito , Ohta Koji , Kinugawa Kenichi
Published: November 2004

The thermal equilibrium state of H5+ is investigated by means of an ab initio path integral molecular dynamics (PIMD) method, in which degrees of freedom of both nuclei and electrons at finite temperature are quantized within the adiabatic approximation. The second-order Møller-Plesset force field has been employed for the present ab initio PIMD. At 5–200 K, H5+ is shown to have the structure that the proton is surrounded by the two H2 units without any exchange of an atom between the central proton and the H2 unit. At 5 K, the quantum tunneling of the central proton occurs more easily when the distance between the two H2 units is shortened. At the high temperature of 200 K, the central proton is more delocalized in space between the two H2 units, with less correlation with the stretching of the distance between the two H2 units. As for the rotation of the H2 units around the C2 axis of H5+, the dihedral angle distribution is homogeneous at all temperatures, suggesting that the two H2 units freely rotate around the C2 axis, while this quantum effect on the rotation of the H2 units becomes more weakened with increasing temperature. The influence of the structural fluctuation of H5+ on molecular orbital energies has been examined to conclude that the highest occupied molecular orbital–lowest unoccupied molecular orbital energy gap is largely reduced with the increase of temperature because of the spatial expansion of the whole cluster.
Lifetime of an emitting dipole near various types of interfaces including magnetic and negative refractive materials
Authors: Ruppin Raphael , Martin Olivier J. F.
Published: November 2004

A classical electromagnetic calculation of the lifetime of an emitting electric dipole near a material slab is presented. The lifetime is deduced from the imaginary part of the electric field Green’s tensor associated with the stratified medium. The method is applied not only to the well known case of metallic reflectors, but also to magnetic reflectors and to negative refractive index slabs. The frequency dependence of the nonradiative decay rate at small distances is analyzed and interpreted in terms of the surface polariton modes of the slab.
Reactive scattering of H2 from Cu(100): Six-dimensional quantum dynamics results for reaction and scattering obtained with a new, accurately fitted potential-energy surface
Authors: Somers M. F. , Olsen R. A. , Busnengo H. F. , Baerends E. J. , Kroes G. J.
Published: November 2004

Six-dimensional quantum dynamical calculations are reported for the dissociative chemisorption of (v=0, 1, j=0) H2 on Cu(100), and for rovibrationally inelastic scattering of (v=1, j=1) H2 from Cu(100). The dynamics results were obtained using a new potential-energy surface (PES5), which was based on density-functional calculations using a slab representation of the adsorbate-substrate system and a generalized gradient approximation to the exchange-correlation energy. A very accurate method (the corrugation reducing procedure) was used to represent the density-functional theory data in a global potential-energy surface. With the new, more accurately fitted PES5, the agreement between the dynamics results and experimental results for reaction and rovibrationally elastic scattering is not as good as was obtained with a previous potential-energy surface (PES4), which was based on a subset of the density-functional theory data not yet including the results for the low-symmetry Cu sites. Preliminary density-functional theory results suggest that the agreement between theory and experiment will improve over that obtained with PES5 if the density-functional calculations are repeated using a larger basis set and using more copper layers than employed in PES4 and PES5.
Network equilibration and first-principles liquid water
Authors: Fernández-Serra M. V. , Artacho Emilio
Published: November 2004

Motivated by the very low diffusivity recently found in ab initio simulations of liquid water, we have studied its dependence with temperature, system size, and duration of the simulations. We use ab initio molecular dynamics (AIMD), following the Born–Oppenheimer forces obtained from density-functional theory (DFT). The linear-scaling capability of our method allows the consideration of larger system sizes (up to 128 molecules in this study), even if the main emphasis of this work is in the time scale. We obtain diffusivities that are substantially lower than the experimental values, in agreement with recent findings using similar methods. A fairly good agreement with D(T) experiments is obtained if the simulation temperature is scaled down by ≈20%. It is still an open question whether the deviation is due to the limited accuracy of present density functionals or to quantum fluctuations, but neither technical approximations (basis set, localization for linear scaling) nor the system size (down to 32 molecules) deteriorate the DFT description in an appreciable way. We find that the need for long equilibration times is consequence of the slow process of rearranging the H-bond network (at least 20 ps at AIMDs room temperature). The diffusivity is observed to be very directly linked to network imperfection. This link does not appear an artifact of the simulations, but a genuine property of liquid water.
Polar solvation dynamics in supercritical fluids: A mode-coupling treatment
Authors: Kapko V. , Egorov S. A.
Published: November 2004

A mode-coupling treatment of polar solvation dynamics in supercritical fluids is presented. The equilibrium solvation time correlation function for the solute fluctuating transition frequency is obtained from the mode-coupling theory method and from molecular-dynamics simulations. The theory is shown to be in good agreement with the simulation. The solvation time correlation function exhibits three distinct time scales, with rapid initial decay, followed by a recurrence at intermediate times, and a slowly decaying long-time tail. Our theoretical analysis shows that the short-time decay arises from the coupling of the solute energy gap to the solvent polarization modes, the recurrence at intermediate times is due to the energy modes, while the slow long-time decay reflects the coupling to the number density modes.
In situ x-ray photoelectron spectroscopic and density-functional studies of Si atoms adsorbed on a C60 film
Authors: Onoe Jun , Nakao Aiko , Hara Toshiki
Published: November 2004

The interaction between C60 and Si atoms has been investigated for Si atoms adsorbed on a C60 film using in situ x-ray photoelectron spectroscopy (XPS) and density-functional (DFT) calculations. Analysis of the Si 2p core peak identified three kinds of Si atoms adsorbed on the film: silicon suboxides (SiOx), bulk Si crystal, and silicon atoms bound to C60. Based on the atomic percent ratio of silicon to carbon, we estimated that there was approximately one Si atom bound to each C60 molecule. The Si 2p peak due to the Si–C60 interaction demonstrated that a charge transfer from the Si atom to the C60 molecule takes place at room temperature, which is much lower than the temperature of 670 K at which the charge transfer was observed for C60 adsorbed on Si(001) and (111) clean surfaces [Sakamoto et al., Phys. Rev. B 60, 2579 (1999)]. The number of electrons transferred between the C60 molecule and Si atom was estimated to be 0.59 based on XPS results, which is in good agreement with the DFT result of 0.63 for a C60Si with C2v symmetry used as a model cluster. Furthermore, the shift in binding energy of both the Si 2p and C 1s core peaks before and after Si-atom deposition was experimentally obtained to be +2.0 and −0.4 eV, respectively. The C60Si model cluster provides the shift of +2.13 eV for the Si 2p core peak and of −0.28 eV for the C 1s core peak, which are well corresponding to those experimental results. The covalency of the Si–C60 interaction was also discussed in terms of Mulliken overlap population between them.
Coarse-grained simulations of lipid bilayers
Authors: Stevens Mark J.
Published: November 2004

A minimal model of lipid molecules consisting of bead-spring representation is developed. The basic interactions are hydrophobic and polar interactions. Essential physical features of lipid bilayers are maintained using this model, and relatively long times can be simulated in comparison to atomistic models. Self-assembly from a random starting configuration to a bilayer can readily be followed using molecular dynamics simulations. The diffusion of lipid molecules well beyond their nearest neighbors is attained. As a basis for description of the model, the area per lipid, the bending modulus, and the area compressibility as a function of temperature and tail length are calculated. A liquid to gel transition is observed and quantitatively characterized. Both saturated and unsaturated lipids are treated.
Structural transformation of molecular nitrogen to a single-bonded atomic state at high pressures
Authors: Eremets M. I. , Gavriliuk A. G. , Serebryanaya N. R. , Trojan I. A. , Dzivenko D. A. , Boehler R. , Mao H. K. , Hemley R. J.
Published: November 2004

The transformation of molecular nitrogen to a single-bonded atomic nitrogen is of significant interest from a fundamental stand point and because it is the most energetic non-nuclear material predicted. We performed an x-ray diffraction of nitrogen at pressures up to 170 GPa. At 60 GPa, we found a transition from the rhombohedral (R3̄c) ε-N2 phase to the ζ-N2 phase, which we identified as orthorhombic with space group P2221 and with four molecules per unit cell. This transition is accompanied by increasing intramolecular and decreasing intermolecular distances. The major transformation of this diatomic phase into the single-bonded (polymeric) phase, recently determined to have the cubic gauche structure (cg-N), proceeds as a first-order transition with a volume change of 22%.
Nonlinear interactions in the density fingering of an acidity front
Authors: Bánsági Tamás , Horváth Dezsö , Tóth Ágota
Published: November 2004

Density fingering of the chlorite-tetrathionate reaction has been studied experimentally in a Hele-Shaw cell. The initially emerging cellular structure transforms into a single cell with constant—asymmetric and symmetric—shape in narrow reaction vessels. The interactions of fingers in wider Hele-Shaw cells lead to the coarsening of the patterns, however, splitting of fingers is observed as well. The long time evolution has been quantitatively described by the change in the mixing length, i.e., the amplitude of the patterns, and by the power-averaged cell number of the structures.
Buffering the entropic cost of hydrophobic collapse in protein chains
Authors: Fernández Ariel
Published: November 2004

Direct inspection of high-resolution protein structures reveals that backbone dehydration promotes extra conformational freedom in the peptide bond, especially when the residue is not involved in secondary structure. The results imply a buffering effect that lowers the entropic cost of hydrophobic collapse.
Zeeman effect in CaF(2Π3/2)
Authors: Krems R. V. , Egorov D. , Helton J. S. , Maussang K. , Nguyen S. V. , Doyle J. M.
Published: November 2004

The Zeeman effect in the excited A 2Π3/2 state of CaF is measured and analyzed over a wide range of magnetic fields. It is found that the splitting of the Zeeman levels is largely determined by the coupling between different rotational states and there are no low-field seeking states in the J=3/2 manifold of Zeeman levels at high magnetic fields. A model of the Zeeman spectrum based on the ligand-field theory of CaF is shown to be accurate in the interval of magnetic fields 0–5 Tesla. This demonstrates that the magnetic moment of the CaF(A 2Π3/2) molecule is effectively determined by the spin angular momentum of a single electron and the orbital motion of the valence electron around the Ca2+ core. An analysis of the Zeeman spectrum as a function of the molecular rotational constant indicates that Π3/22 molecules should have significant rotational constants (at least as large as twice the rotational constant of CaF) to be amenable to magnetic trapping in high fields.
Phase transitions and hindered rotation in dimethylacetylene at high pressures probed by Raman spectroscopy
Authors: Baonza V. G. , Montoro O. R. , Taravillo M. , Cáceres M. , Núñez J.
Published: November 2004

We present Raman spectroscopy experiments in dimethylacetylene (DMA) using a sapphire anvil cell up to 4 GPa at room temperature. DMA presents phase transitions at 0.2 GPa (liquid to phase I) and 0.9 GPa, which have been characterized by changes in the Raman spectrum of the sample. At pressures above 2.6 GPa several bands split into two components, suggesting an additional phase transition. The Raman spectrum of the sample above 2.6 GPa is identical to that found for the monoclinic phase II (C2/m) at low temperatures, except for an additional splitting of the band assigned to the fourfold degenerated asymmetric methyl stretch. The global analysis of the Raman spectra suggests that the observed splitting is due to the loss of degeneracy of the methyl groups of the DMA molecule in phase II. According to the above interpretation, crystal phase II of DMA extends from 0.9 GPa to pressures close to 4 GPa. Between 0.9 and 2.6 GPa, the methyl groups of the DMA molecules rotate almost freely, but the rotation is hindered on further compression.
Correlation energy extrapolation by intrinsic scaling. III. Compact wave functions
Authors: Bytautas Laimutis , Ruedenberg Klaus
Published: November 2004

The information gained in the context of extrapolating the correlation energy by intrinsic scaling is used to shorten the full configurational expansions of electronic wave function without compromising their chemical accuracy. The truncations are accomplished by judiciously limiting the participation of the ranges of predetermined approximate sets of natural orbitals in the various excitation categories.
Response to: “Comment on ‘Disentangling density and temperature effects in the viscous slowing down of glassforming liquids’ ” [J. Chem. Phys. 121, 11503 (2004)]
Authors: Tarjus Gilles , Mossa S. , Alba-Simionesco C.
Published: November 2004

Although density plays a role at a quantitative level in the viscous slowing down of glassformers, its effect can be scaled out by introducing an effective energy E∞(ρ) characteristic of the high-temperature liquid regime. It is argued that a power-law fit of E∞(ρ) has no substantial physical meaning.
Integral equation theory for athermal solutions of linear polymers
Authors: Chatterjee Avik P.
Published: November 2004

An integral equation model is developed for athermal solutions of flexible linear polymers with particular reference to good solvent conditions. Results from scaling theory are used in formulating form factors for describing the single chain structure, and the impact of solvent quality on the chain fractal dimension is accounted for. Calculations are performed within the stringlike implementation of the polymer reference interaction site model with blobs (as opposed to complete chains) treated as the constituent structural units for semidilute solutions. Results are presented for the second virial coefficient between polymer coils and the osmotic compressibility as functions of the chain length and polymer volume fraction, respectively. Findings from this model agree with results from scaling theory and experimental measurements, as well as with an earlier investigation in which self-avoiding chains were described using Gaussian form factors with a chain length and concentration-dependent effective statistical segment length. The volume fractions at the threshold for connectedness percolation are evaluated within a coarse-grained closure relation for the connectedness Ornstein-Zernike equation. Results from these calculations are consistent with the usual interpretation of the semidilute crossover concentration for model solutions of both ideal and swollen polymer coils.
Structural investigations of polymer electrolyte poly(propylene oxide)-LiClO4 using diffraction experiments and reverse Monte Carlo simulation
Authors: Carlsson P. , Andersson D. , Swenson J. , McGreevy R. L. , Howells W. S. , Börjesson L.
Published: November 2004

The structure of an amorphous polymer electrolyte, poly(propylene oxide) (PPO) complexed with LiClO4, has been studied using reverse Monte Carlo (RMC) simulations. The simulations require no force field but are based on experimental data only, in this case from x-ray and neutron diffraction experiments. Excellent agreement between the experimental data and the structures resulting from the RMC simulation is obtained. Samples with ether-oxygen to lithium concentrations (molar ratios) O:Li=16:1 and 5:1 were studied and compared to results of pure PPO from a previous study. We focus on the effects of the solvated salt on the structure of the polymer matrix, the spatial distribution of ions, and the correlations between the anions and the polymer chains. Analyzing the structures produced in the simulations, we find that for a concentration 16:1, the interchain distance is approximately the same as in pure PPO but more well defined. For a concentration 5:1, we find a larger and less well-defined interchain distance compared to the 16:1 concentration. This signifies that at the 16:1 salt concentration, there is enough free volume in the polymer host to accommodate the ions, and that the solvation of salt induces ordering of the polymer matrix. At the higher salt concentration 5:1, the polymer network must expand and become less ordered to host the ions. We also note, in accordance with previous studies, that the solvation of salt changes the conformation of the polymer chain towards more gauche states. The simulations furthermore reveal marked correlations between the polymer chains and the anions, which we suggest arise predominantly from an interaction mediated via cations, which can simultaneously coordinate both ether oxygens in the polymer chains and anions. Interanionic distances at 5 Å, which are consistent with two or more anions being coordinated around the same cation, are also observed. On a larger scale, the RMC structure of PPO-LiClO4 16:1 clearly indicates the presence of salt-rich and salt-depleted domains having a length scale of <20 Å. In view of such a heterogeneous structure of PPO-LiClO4 16:1, it is plausible that the increased ordering of the polymer matrix is due to rather well-defined structural arrangements within the salt-rich domains, and that the characteristic interchain distance in the salt-rich domains is similar to that of the pure polymer.
Semiclassical Liouville method for the simulation of electronic transitions: Single ensemble formulation
Authors: Roman Eduardo , Martens Craig C.
Published: November 2004

In this paper, we describe a single ensemble implementation of the semiclassical Liouville method for simulating quantum processes using classical trajectories. In this approach, one ensemble of trajectories supports the evolution of all semiclassical density matrix elements, rather than employing a distinct ensemble for each. The ensemble evolves classically under a single reference Hamiltonian, which is chosen based on physical grounds; for electronic relaxation of an initially excited state, the initially populated upper surface Hamiltonian is the natural choice. Classical trajectories evolving on the reference potential then represent the time-dependent upper state population density and also the electronic coherence and the ground state density created by electronic transition. The error made in the classical motion of the trajectories for these latter distributions is compensated for by incorporating the difference between the correct and reference Liouville propagators into the calculation of the coefficients of the individual trajectories. This approach gives very accurate results for a number of model problems and cases describing ultrafast electronic relaxation dynamics.
Single-chip mechatronic microsystem for surface imaging and force response studies
Authors: Hafizovic Sadik , Barrettino Diego , Volden Tormod , Sedivy Jan , Kirstein Kay-Uwe , Brand Oliver , Hierlemann Andreas
Published: November 2004

We report on a stand-alone single-chip (7 × 10 mm) atomic force microscopy unit including a fully integrated array of cantilevers, each of which has an individual actuation, detection, and control unit so that standard atomic force microscopy operations can be performed by means of the chip only without any external controller. The system offers drastically reduced overall size and costs as well as increased scanning speed and can be fabricated with standard complementary metal oxide semiconductor technology with some subsequent micromachining steps to form the cantilevers. Full integration of microelectronic and micromechanical components on the same chip allows for the controlling and monitoring of all system functions. The on-chip circuitry, which includes analog signal amplification and filtering stages with offset compensation, analog-to-digital converters, a powerful digital signal processor, and an on-chip digital interface for data transmission, notably improves the overall system performance. The microsystem characterization evidenced a vertical resolution of <1nmand a force resolution of <1 nN as shown in the measurement results. The monolithic system represents a paradigm of a mechatronic microsystem that allows for precise and fully controlled mechanical manipulation in the nanoworld.
Cooperative extraction of membrane nanotubes by molecular motors
Authors: Leduc Cécile , Campàs Otger , Zeldovich Konstantin B. , Roux Aurélien , Jolimaitre Pascale , Bourel-Bonnet Line , Goud Bruno , Joanny Jean-François , Bassereau Patricia , Prost Jacques
Published: November 2004

In eukaryotic cells, nanotubes represent a substantial fraction of transport intermediates between organelles. They are extracted from membranes by molecular motors walking along microtubules. We previously showed that kinesins fixed on giant unilamellar vesicles in contact with microtubules are sufficient to form nanotubes
in vitro
. Motors were attached to the membrane through beads, thus facilitating cooperative effects. Koster
et al.
[Koster, G., VanDuijn, M., Hofs, B. & Dogterom, M. (2003)
Proc. Natl. Acad. Sci. USA
100, 15583–15588] proposed that motors could dynamically cluster at the tip of tubes when they are individually attached to the membrane. We demonstrate, in a recently designed experimental system, the existence of an accumulation of motors allowing tube extraction. We determine the motor density along a tube by using fluorescence intensity measurements. We also perform a theoretical analysis describing the dynamics of motors and tube growth. The only adjustable parameter is the motor binding rate onto microtubules, which we measure to be 4.7 ± 2.4 s
–1
. In addition, we quantitatively determine, for a given membrane tension, the existence of a threshold in motor density on the vesicle above which nanotubes can be formed. We find that the number of motors pulling a tube can range from four at threshold to a few tens away from it. The threshold in motor density (or in membrane tension at constant motor density) could be important for the understanding of membrane traffic regulation in cells.
Property and intellectual property: foundations in law and economics1
Authors: MAUGHAN† C. W
Published: November 2004

The simplicity of the lay view, the complexity of the legal and economic concepts of ownership and property, and the real life gains that are to be made from using the simplistic view to justify the creation of monopoly rights, has led to considerable and often deliberate confusion in discussions about intellectual property. To reduce the confusion, this paper considers the legal and economic aspects of property. First the legal taxonomy of property, including intellectual property, is described. Then, a law and economics model of intellectual property is built, stressing not only the economic gains but also the economic losses that result from treating property as some ‘thing’ that can be monopolised. The paper then argues that the central policy issue is to devise methods of creating and protecting intellectual property that balance the gains from creation and protection (incentives to invest, improvements in information markets) against the losses (potential monopolisation of knowledge). A tentative conclusion is drawn that such a policy may well involve weakening present copyright and patent rights, and treating copyright and patents as if they were more analogous to trademarks. Alternatives might be to require greater dissemination of protected intellectual property by allowing two part pricing in different markets.
Disabled e‐nation: telecommunications, disability, and national policy
Authors: GOGGIN GERARD , NEWELL CHRISTOPHER
Published: November 2004

This article considers questions of technological change, innovation, and communication from a disability perspective. Using a critical social perspective on disability, we offer an Australian case study to analyse disability in national telecommunications policy. In doing so, we critique the systemic lack of incorporation of disability in national visions, policies, and programmes. Accordingly, we argue for a cohesive, and genuine commitment to incorporating disability considerations in all areas of information and communication technology policy and scholarship.
Emerging patterns of cannabis and other substance use in Aboriginal communities in Arnhem Land, Northern Territory: a study of two communities
Authors: CLOUGH ALAN R. , D'ABBS PETER , CAIRNEY SHEREE , GRAY DENNIS , MARUFF PAUL , PARKER ROBERT , O'REILLY BRIDIE
Published: November 2004

A recent rise in cannabis use in Indigenous communities in northern Australia may have compounded existing patterns of other substance use. This paper describes these patterns in Arnhem Land in the ‘Top End’ of the Northern Territory (NT). Economic impacts of the cannabis trade are also described. In a descriptive cross‐sectional study, random samples included 336 people (169 males, 167 females) aged 13–36 years. Consensus classification of lifetime and current use of cannabis, alcohol, tobacco, kava, inhalants (petrol) and other drugs was derived based on health workers’ proxy assessments. A sample (n = 180, aged 13–36) was recruited opportunistically for interview. Lifetime cannabis users among those interviewed (n = 131, 81 males, 50 females) described their current cannabis use, usual quantities purchased and consumed, frequency and duration of cannabis use and other substance use. In the random samples, 69% (63–75%) of males and 26% (20–31%) of females were lifetime cannabis users (OR = 7.4, 4.5–12.1, p 5 0.001). The proportion of males currently using cannabis was 67% (60–73%) while the proportion of females currently using cannabis was 22% (16–27%) (OR = 7.9, 4.8–13.1, p 5 0.001). Current cannabis users were more likely than non‐users to be also using alcohol (OR = 10.4, 4.7–23.3, p 5 0.001), tobacco (OR = 19.0, 7.9–45.8, p 5 0.001) and to have sniffed petrol (OR = 9.1, 4.6–18.0, p 5 0.001) but were less likely to be using kava (OR = 0.4, 0.2 –0.9, p 5 0.001). Among those interviewed, higher tobacco consumption in current users and greater alcohol use in lifetime users was associated with increased cannabis use. Action is required to reduce cannabis use, especially in combination with other substances.
General practitioners' role in preventive medicine: scenario analysis using alcohol as a case study
Authors: DORAN CHRISTOPHER M. , SHAKESHAFT ANTHONY P. , FAWCETT JULIA E.
Published: November 2004

The purpose of this analysis is threefold: first, to extract from the literature, current levels of GP detection of at‐risk drinking by their patients, rates at which general practitioners (GPs) offer an intervention; and the effectiveness of these interventions; secondly, to develop a model based on this literature to be used in conjunction with scenario analysis; and thirdly, to consider the cost implications of current efforts and various scenarios. This study deals specifically with Australian general practice. A two‐step procedure is used in the scenario analysis, which involves identifying opportunities for detection, intervention, effectiveness and assigning probabilities to outcomes. The results suggest that increasing rates of GP intervention achieves greatest benefit and return on resource use. For every 5% point increase in the rate of GP intervention, an additional 26 754 at‐risk drinkers modify their drinking behaviour at a cost of $231.45 per patient. This compares with a cost per patient modifying drinking behaviour of $232.60 and $208.31 for every 5% point increase in the rates of detection and effectiveness, respectively. The knowledge, skill and attitude of practitioners toward drinking are significant, and they can be the prime motivators in persuading their patients to modify drinking behaviour.
Reasons for cannabis use in men with and without psychosis
Authors: GREEN BOB , KAVANAGH DAVID J. , YOUNG ROSS MCD
Published: November 2004

Psychoses are relatively low prevalence disorders that have a disproportionately negative impact on individuals and society. Cannabis use is one factor that can exacerbate the negative consequences associated with psychotic disorders. Relatively few studies have examined the effects or reasons for using cannabis self‐reported by individuals with psychosis. The present study is the first known to compare directly such factors in individuals with and without psychosis, within a single study. At baseline and follow‐up participants with psychosis most commonly reported using cannabis for positive mood alteration (36% and 42%), coping with negative affect (27% and 29%) and for social activity reasons (38% and 29%). The control group most commonly reported using cannabis for relaxation (34% and 43%) and social activity reasons (49% and 51%). Participants with psychosis were less likely to report relaxation as the most important effect after use (27%) or expect it at follow‐up (49%) compared to the control group (53% and 70%). In both groups, addiction and positive affect enhancement were the composite variable scores correlated most consistently with concurrent amount and frequency of use.
Harm reduction and the global drug control regime: contemporary problems and future prospects*
Authors: BEWLEY‐TAYLOR DAVID R.
Published: November 2004

Countries committed to a harm‐reduction approach to drugs have exploited the latitude which exists within the UN global drug control regime to implement strategies which deviate from the strict prohibition ethos of the conventions. These nations risk pressure being brought to bear through the UN drug control regime, principally by the United States, determined to prevent what it sees as foreign challenges to its domestic ‘zero tolerance’ approach and its internationalisation. In this paper, based on his presentation to the International Conference on the Reduction of Drug Related Harm in Melbourne this year, David Bewley‐Taylor, describes the conventions and the ‘wiggle room’ which exists, but also imagines ways like‐minded states might together challenge and reform the conventions so that harm reduction can be accepted and hard wired into the UN drug control system itself.
“To Be” or “Ought To Be”: The Questions of Empirical Content and Normative Bias in Léon Walras's Methodology
Authors: Debs Alexandre
Published: November 2004

Léon Walras was a truly revolutionary economist. Not only did he leave a lasting mark on economic doctrine participating in the Marginalist Revolution, which supplanted the labor theory of value of the classical school, but he also contributed to major changes in economic methodology as being one of the first and most ardent promoters of the use of mathematics in economics. For an actor who played such a great role in the development of economics, how did he conceive his scientific endeavor? This question can be broken down into two different but related questions: First, how did he know that he had found true scientific laws? What was his theory of knowledge? Is it best described as empiricist (claiming that all knowledge comes from experience) or idealist (claiming that reason can achieve knowledge independently of experience)? And, second, what relation did his writings on pure theory bear with his policy prescriptions? Was there a normative bias in Léon Walras's methodology, i.e., were his positive statements molded by his normative inclinations?

This last set of questions has generated much debate, given that Walras actively fought for scientific rigor while not refraining from defending his views on the desired social order. For W. Jaffé, who unearthed his correspondence, a careful study of primary evidence shows that Walras's conception of justice heavily influenced his search for pure truth. TheÉléments d'économie politique pure(Éléments), “appears, on the surface, as a competelywert-frei” system, but it is nevertheless “inform[ed]” by “implicit moral convictions” (Jaffé 1977, p. 371). However, D. A. Walker has strongly attacked Jaffe's allegation that Walras's theory of general equilibrium was deliberately constructed as a normative scheme, pointing to Walras's “careful distinctions between normative and positive subject matters” (Walker 1984, p. 466).
Marshall: Just how Interested in Doing Good was he?
Authors: Bowman Rhead S.
Published: November 2004

This paper critiques the way Alfred Marshall is presented in many histories of economic thought, in particular, the typical neglect of the relation of his economic theory and method to his public policy proposals and views on economic evolution. A good example is the textbook of Stanley L. Brue,The Evolution of Economic Thought, which is specifically policy oriented. He notes in his remarks on Marshall's life and method: “Marshall's thinking left room for cautious reform, that is, modest departures from laissez-faire” (2000, p. 295). But the only illustration of this is Marshall's discussion of the welfare effects of industry taxes and subsidies. However, even here Brue concludes (2000, p. 316) with a quote from Marshall: “These conclusions, it will be observed, do not by themselves afford a valid ground for government interference.”
Wilhelm Launhardt and Bid-Rent Curves: A Note
Authors: Shieh Yeung-Nan
Published: November 2004

One of the very important components in the urban and agricultural land use model is the so-called bid-rent curve. Regional and urban economists, city planners, and economic geographers have used this curve extensively as an analytical device. It is generally accepted that the explicit bid-rent function was first applied to the equilibrium of land use patterns in agricultural production by August Losch (1954) in Germany and Edgar S. Dunn (1954) in America, and was later extended by William Alonso (1964).
Double‐Blind Placebo‐Controlled Trial of Fluoxetine in Smoking Cessation Treatment Including Nicotine Patch and Cognitive‐Behavioral Group Therapy
Authors: Saules Karen K. , Schuh Leslie M. , Arfken Cynthia L. , Reed Karen , Kilbey M. Marlyne , Schuster Charles R.
Published: November 2004

Smoking cessation attempts are often complicated by dysphoria/depression, weight gain, craving, and other nicotine withdrawal symptoms. Fluoxetine's antidepressant and anorectant properties, along with its capacity to attenuate compulsive behavior, suggest that this medication might facilitate smoking cessation treatment. We examined the effect of fluoxetine on smoking cessation in the context of a program that included group cognitive‐behavioral therapy (six weeks) and transdermal nicotine patch (ten weeks). In a double‐blind randomized trial of fluoxetine for smoking cessation, 150 daily smokers were assigned to placebo (n = 48), 20 mg (n = 51), or 40 mg fluoxetine (n = 51). Fluoxetine did not significantly improve smoking cessation rates, either for those with or without major depressive disorder (MDD) histories or elevated current depression. Our results suggest that fluoxetine may moderate withdrawal symptoms, even if that was not manifested in improved smoking cessation rates. Our results, however, clearly favor the use of fluoxetine if weight gain is a major clinical obstacle to smoking cessation.
Factors Associated with Treatment Outcomes in an Aftercare Population
Authors: Brown Barry S. , O'Grady Kevin , Battjes Robert J. , Farrell Eugene V.
Published: November 2004

This study examined six‐month outcomes for 194 criminal justice clients exiting outpatient drug‐free treatment and assigned to aftercare or standard treatment. It compared sub‐samples of those achieving positive (n = 111) and negative outcomes (n = 59), as defined by drug and alcohol use and arrests. Psychological variables and attendance at religious services distinguished significantly between groups. Predictor variables developed from that comparison were employed in logistic regression analyses making use of the full sample. Aftercare was found to be particularly significant for reduction in drug use, with optimism)pessimism about one's future and religious observance also significant predictors for substance use.
Effects of self‐modelling on stuttering
Authors: Webber Margaret J. , Packman Ann , Onslow Mark
Published: November 2004

Background: The paper reports on a laboratory investigation of the effects of self‐modelling on stuttering rate in adolescents and adults. Self‐modelling refers to a therapeutic or training method, usually involving videotape, that uses exposure to oneself performing selected error‐free behaviours as the conduit for promoting behaviour change.

Aims: To investigate self‐modelling in single‐subject experiments to determine whether any reductions in stuttering could be directly attributable to watching self‐modelling videotapes and to ascertain whether instruction to focus attention on the target behaviour, namely stutter‐free speech, was necessary for experimental effects.

Methods & Procedures: A single‐subject withdrawal design was employed with two adult men and an adolescent boy. Speaking sessions during all phases of the study were of 3‐min duration. During the B Phase, subjects watched one of their self‐modelling videotapes, which had been edited to remove all stuttered speech, before each speaking session. In the B+C Phases, subjects continued to watch the self‐modelling videotapes before each speaking session and, in addition, were instructed to attempt to speak during the session as they had spoken on the videotape.

Outcomes & Results: Stuttering reduced under self‐modelling conditions for one of the three subjects. This effect was observed during the B+C Phases, which included instruction to attend to the target behaviour.

Conclusions: The study provides laboratory evidence that self‐modelling can ameliorate stuttering. The clinical implications of this finding are that treatments for adults may well benefit from the inclusion of self‐modelling procedures, and self‐modelling procedures may form a part of relapse prevention and management strategies.
PTB or Not to Be: Promiscuous, Tolerant and Bizarro Domains Come of Age
Authors: Farooq Amjad , Zhou Ming‐Ming
Published: November 2004

PTB domains are protein modules that usually interact with the cytoplasmic tail of a wide variety of growth factor receptors. In so doing, they mediate the transduction of extracellular information to specific downstream targets within the cell that ultimately determine the fate of a number of important biological processes such as cell growth and differentiation, cell cycle regulation and apoptosis. Recent structural and functional studies of PTB domains from a variety of cellular proteins have begun to shed light on the molecular mechanisms of action of these important protein modules. In the present review, we provide an account of such studies and suggest that PTB domains can be subdivided into three distinct categories on the basis of their topological differences. We also discuss the various mechanisms employed by the PTB domains in recognition of a diverse set of ligands without a consensus sequence. Finally, we discuss the role of molecular plasticity as a possible determinant of functional versatility of PTB domains. IUBMB Life, 56: 547‐557, 2004
Cadherin activity is required for activity-induced spine remodeling
Authors: Okamura Ko , Tanaka Hidekazu , Yagita Yoshiki , Saeki Yoshinaga , Taguchi Akihiko , Hiraoka Yasushi , Zeng Ling-Hui , R Colman David , Miki Naomasa
Published: November 2004

Neural activity induces the remodeling of pre- and postsynaptic membranes, which maintain their apposition through cell adhesion molecules. Among them, N-cadherin is redistributed, undergoes activity-dependent conformational changes, and is required for synaptic plasticity. Here, we show that depolarization induces the enlargement of the width of spine head, and that cadherin activity is essential for this synaptic rearrangement. Dendritic spines visualized with green fluorescent protein in hippocampal neurons showed an expansion by the activation of AMPA receptor, so that the synaptic apposition zone may be expanded. N-cadherin-venus fusion protein laterally dispersed along the expanding spine head. Overexpression of dominant-negative forms of N-cadherin resulted in the abrogation of the spine expansion. Inhibition of actin polymerization with cytochalasin D abolished the spine expansion. Together, our data suggest that cadherin-based adhesion machinery coupled with the actin-cytoskeleton is critical for the remodeling of synaptic apposition zone.
A neuroscientific approach to normative judgment in law and justice
Authors: Zeki S. , Goodenough O. R. , Goodenough Oliver R. , Prehn Kristin
Published: November 2004

Developments in cognitive neuroscience are providing new insights into the nature of normative judgment. Traditional views in such disciplines as philosophy, religion, law, psychology and economics have differed over the role and usefulness of intuition and emotion in judging blameworthiness. Cognitive psychology and neurobiology provide new tools and methods for studying questions of normative judgment. Recently, a consensus view has emerged, which recognizes important roles for emotion and intuition and which suggests that normative judgment is a distributed process in the brain. Testing this approach through lesion and scanning studies has linked a set of brain regions to such judgment, including the ventromedial prefrontal cortex, orbitofrontal cortex, posterior cingulate cortex and posterior superior temporal sulcus. Better models of emotion and intuition will help provide further clarification of the processes involved. The study of law and justice is less well developed. We advance a model of law in the brain which suggests that law can recruit a wider variety of sources of information and paths of processing than do the intuitive moral responses that have been studied so far. We propose specific hypotheses and lines of further research that could help test this approach.
Law and the brain: Introduction
Authors: Zeki S. , Goodenough O. R. , Zeki Semir , Goodenough Oliver
Published: November 2004

Combining law and the brain as a matter for study requires the integration not just of two apparently remote fields of study but also of two profoundly different orientations towards research and study. We believe that, in spite of the difficulties, such a combination, perhaps even emerging in a new specialized discipline in the future, will not only enrich both fields but is the ineluctable consequence of the current assault on the secrets of the brain. The effort to bring the fields together is therefore a worthy task, and this issue is the first systematic effort to test this expectation.
Training and learning as drivers of US microenterprise business plan quality
Authors: Cook Ronald G. , Belliveau Paul , Sandberg Mark E.
Published: November 2004

This study examined the output quality of a US microenterprise training program created to help entrepreneurs develop business plans for their ventures. The program concludes with the entrepreneurs' plans being scored by a panel of experts. Hypotheses were developed and tested to determine the importance of feedback, key components of business plan scores, and differences between teams and solo entrepreneurs. Timely feedback on business plan homework was the most significant driver of business plan quality, contributing to higher scores on the written plan and on the plan's presentation to the expert panel. Plans developed by teams also scored higher than those prepared by solo entrepreneurs.
Toward an understanding of people management issues in SMEs: a South‐Eastern European perspective
Authors: Szamosi Leslie T. , Duxbury Linda , Higgins Chris
Published: November 2004

The focus of this paper is on developing an understanding, and benchmarking, human resource management (HRM) issues in small and medium enterprises (SMEs) in South‐Eastern Europe. The importance of SME's in helping transition‐based economies develop is critical, but at the same time the research indicates that the movement toward westernized business systems has a dramatic impact on the human resources within such businesses. Toward addressing this linkage, critical HRM issues related to work outcomes, measures of satisfaction, and managerial support were studied with a sample of nearly 300 employees from 21 SMEs in a country in South‐Eastern Europe (the Former Yugoslav Republic of Macedonia). The data suggest that SMEs are not currently giving their employees what they want from their job (e.g. career development, participation in decision making) and that women are treated differently than men creating an imbalance within the workforce. From these data recommendations are drawn for SMEs on how to move forward as transition unfolds.
How to organise the digital library: reengineering and change management in the Bayerische Staatsbibliothek, Munich
Authors: Schäffler Hildegard
Published: November 2004

The introduction of digital resources has not only had considerable impact on the role of libraries in the information society, but it has also had a remarkable effect on back office procedures, i.e. on the way the library is organised. This article presents a case study of a reengineering process at the Bayerische Staatsbibliothek (Bavarian State Library) in Munich, Germany, the central regional library of the State of Bavaria and one of the largest academic research libraries in Europe with local, regional and supraregional responsibilities. Due to the multiple roles of this library, it was particularly important not only to bridge the gap between traditional and new material, but also to create a flexible organisational platform for the various tasks at the different levels indicated.