bluuebunny/crossref_metadata_2025 huggingface dataset:
Micromagnetic analyses of reversal process with twisted wall structure
Authors: Yorozu Takehiko , Hu Xiao
Published: April 2004

The magnetization reversal process in a magnetic film is discussed with a focus on the effects of surface anisotropy. Assuming an adiabatic rotation of magnetization, the entire configuration is determined by applying the variational technique to the total energy of the system including the surface and bulk anisotropy energy, the exchange energy, and also Zeeman energy. The magnetization reversal can proceed through both coherent and/or incoherent rotations depending on the values of magnetization, anisotropy, exchange stiffness, and film thickness. In the case of incoherent rotation, the magnetization configuration exhibits the normal twisted wall structure. The expression for the bifurcating condition is given explicitly.
Optical breakdown processing: Influence of the ambient gas on the properties of the nanostructured Si-based layers formed
Authors: Yang D.-Q. , Kabashin A. V. , Pilon-Marien V.-G. , Sacher E. , Meunier M.
Published: April 2004

Porous nanostructured layers, exhibiting 2–2.2 eV photoluminescent (PL) emission, have been formed on silicon surfaces by the production of optical breakdown in different gases (air, Ar2, He,N2, O2), maintained at atmospheric pressure. We found a significant influence of the ambient gas characteristics on the morphological and chemical properties of the layers produced, as well as on the PL efficiency. Gases with relatively low ionization potentials (air, N2,O2) were found to better support the optical discharge and to provide the strongest plasma-related heating of the substrate material. This led to considerable microstructural and composition modifications, which gave rise to the maximization of PL emissions. In particular, for O2, with the lowest ionization potential, we observed local plasma-provoked melting of the target surface and the disappearance of the porous structure of the layer. We also found a clear correlation between the PL properties of the layers, subsequent to fabrication, as well as after prolonged aging, and the presence of different oxygen-containing compounds. The structures produced are of importance for optoelectronics and biosensing applications.
Electron acceleration in the dynamic magnetotail: Test particle orbits in three-dimensional magnetohydrodynamic simulation fields
Authors: Birn J. , Thomsen M. F. , Hesse M.
Published: April 2004

Electron acceleration and energetic electron flux increases in the inner tail are investigated on the basis of test-particle orbits in the dynamic fields of a three-dimensional magnetohydrodynamic simulation of neutral line formation and dipolarization in the magnetotail. Past models have mostly considered equatorial orbits, using the gyrocenter drift approximation. In this paper, the investigation is extended to include nonequatorial drifts and full orbit integrations in regions where the drift approximation breaks down. Typical acceleration mechanisms consist of betatron acceleration at large pitch angles and Fermi acceleration at small pitch angles, resulting from the dipolarization and shortening of field lines moving earthward from the neutral line. In comparison, acceleration at the near-Earth neutral line plays a negligible role in flux increases observed in the near tail. Energetic electron fluxes appear preferentially enhanced around 90° pitch angle, so that restriction to those pitch angles might lead to an overestimate of flux increases. Otherwise, the results explain the observed limitation of the range of flux enhancements between a few keV and a few hundred keV.
Kinetic pathways to visible emission from a moly–oxide–argon discharge bulb
Authors: Petrov G. M. , Giuliani J. L. , Dasgupta A. , Bartschat K. , Pechacek R. E.
Published: April 2004

A low-pressure mercury-free moly-oxide–argon (MoO3–Ar) electrodeless discharge is investigated with potential application to lighting. The inductive discharge is driven by a 13.56 MHz radio frequency (RF) generator at input powers between 100 and 200 W. Calibrated emission spectra in the near ultraviolet (UV), visible, and near infrared regions are recorded and the corresponding powers emitted as radiation are obtained. An extensive set of transition probabilities and rate coefficients for electron impact excitation between Mo states is assembled and a detailed collisional radiative model of the plasma is developed. The model includes 11 states of neutral Mo, the evaporative and recycling chemistry of MoO3 into Mo and back, and the relevant species and reactions in argon–oxygen plasma. The possible paths for visible and UV radiation are analyzed in detail. The measured light output at 200 W RF input power is ∼40 lumens per watt (lpw) with a potential to reach ∼60–80 lpw. Comparison of the model with data for various radiated powers and electron density shows reasonable agreement.
Optical properties of Nd3+ ions in oxyfluoride glasses and glass ceramics comparing different preparation methods
Authors: Abril M. , Méndez-Ramos J. , Martı́n I. R. , Rodrı́guez-Mendoza U. R. , Lavı́n V. , Delgado-Torres A. , Rodrı́guez V. D. , Núñez P. , Lozano-Gorrı́n A. D.
Published: April 2004

A study of optical properties of Nd3+ doped oxyfluoride glasses and glass ceramics prepared by three different methods has been carried out. These methods start from NdF3, Nd2O3, or a Nd3+ ion solution as doping agent. The alternative preparation method based on a preliminary dissolution of the Nd3+ ions is proposed in order to avoid nonhomogeneous dopant distribution and spontaneous devitrification during glass elaboration. In the frame of the Judd–Ofelt theory, main radiative parameters have been studied: transition probabilities, lifetimes, and stimulated emission cross sections. Fluorescence decay curves have been also analyzed in order to study the final distribution of the Nd3+ ions after the ceramming process, discerning between ions that reside in the fluoride nanocrystals precipitated during heat treatment and those remaining in the glassy phase. The NdF3 based glass ceramics present the best values for spectroscopic parameters as the stimulated cross section of the F3/24→I11/24 laser transition.
Raman identification of the in-plane axes of zincblende (100) surfaces: Basic principles and application to II–VI/III–V heterostructures
Authors: Muck T. , Wagner J. W. , Hansen L. , Wagner V. , Geurts J.
Published: April 2004

We use the interference of deformation-potential- and Fröhlich-induced Raman scattering from LO phonons in zincblende materials to identify the in-plane axes of zincblende (100) surfaces and interfaces. This procedure, which allows e.g. to distinguish between the [011] and the [0–11] direction, is demonstrated experimentally for n- and p-type GaAs(100). The main potential of the method is its application to heterostructures. Here it allows the unambiguous assignment of polarized Raman scattering features from surfaces and interfaces to their characteristic symmetry directions. Two examples are presented: (i) localized vibrations of CdSe monolayers, embedded in BeTe stacks, and (ii) vibration modes of Te dimers on clean (2×1) reconstructed BeTe(100) surfaces.
Core-level photoemission and near-edge x-ray absorption fine-structure studies of GaN surface under low-energy ion bombardment
Authors: Petravic Mladen , Deenapanray Prakash N. K. , Coleman Victoria A. , Kim Ki-jeong , Kim Bongsoo , Li Gang
Published: April 2004

We have investigated compositional changes on GaN surfaces under low-energy Ar ion bombardment using synchrotron-based high-resolution core-level photoemission measurements and near-edge x-ray absorption fine-structure (NEXAFS) spectroscopy. The low-energy ion bombardment of GaN produces a Ga-rich surface layer which transforms into a metallic Ga layer at higher bombarding energies. At the same time, the photoemission spectra around the N 1s core level reveal the presence of both uncoordinated nitrogen and nitrogen interstitials, which we have analyzed in more detail by x-ray absorption measurements at the N K-edge. We have proposed a mechanism for the relocation and loss of nitrogen during ion bombardment, in agreement with some recent experimental and theoretical studies of defect formation in GaN. We have also demonstrated that photoemission spectroscopy and NEXAFS provide a powerful combination for studying compositional changes and the creation of point defects at GaN surface.
Effect of poloidal sheared flow on the long-range correlation characters of edge plasma turbulent transport
Authors: Wang W. H. , Yu C. X. , Wen Y. Z. , Wang L. , Yang X. Z. , Feng C. H.
Published: April 2004

The long-range correlation characteristics of the turbulence-induced particle transport fluxes measured in the plasma edge region of the Chinese Tokamak-6B (CT-6B) [X. Yang et al., Nucl. Fusion 36, 1669 (1996)] have been investigated. The Hurst exponent calculations and the power spectra exhibit the self-similarity and long-range correlation character of the particle transport fluxes. The rescaled probability distribution functions (PDF’s) of the local fluxes are found to be self-similar, with the self-similarity parameter well above 0.5 in the range of time scales between the turbulence decorrelation and confinement time. The decorrelation effect of the E×B flow shear on the long-range correlation character of the flux has been identified by the changes in the radial dependences of the Hurst parameter, spectral decay index, and the outward flux tail of the PDF near the flow shear layer. This suggests that the mechanism for these changes is the simple decorrelation of the large-scale transport events by the shear flow.
Cobalt growth on Cu(111) in the presence of indium surfactant
Authors: Wider H. , Gimple V. , Evenson W. , Schatz G. , Jaworski J. , Marszałek M.
Published: April 2004

The effect of a pre-deposited ultrathin film of indium on the deposition of cobalt on Cu(111) has been studied by an in situ combination of medium energy electron diffraction, scanning tunneling microscopy, and Auger electron spectroscopy. Pre-deposited indium allows cobalt to deposit in layer-by-layer growth, in contrast to the three-dimensional growth observed without the indium surfactant. The surfactant effect is connected to the surface alloys, Cu2In and Cu3In, that form upon indium pre-deposition. Initial cobalt nucleation processes and indium segregation during cobalt deposition are also discussed.
On computing the thermal-slip coefficient from Kramers’ problem
Authors: Siewert C. E.
Published: April 2004

Classical techniques are used to derive a variant of an Onsager relation (used typically for Poiseuille flow and thermal-creep flow) that yields a convenient relationship between the heat flow of Kramers’ problem and the thermal-slip coefficient. The analysis is based on the linearized Boltzmann equation for rigid-sphere interactions, and wall interactions are described by a general law that includes, for example, the Maxwell model (a mixture of specular and diffuse reflection) and the Cercignani–Lampis model.
Synergistic enhancement of glyphosate uptake into grasses by adjuvant combinations
Authors: Liu Z. Q.
Published: April 2004

The influence of various adjuvant combinations on the uptake of glyphosate was examined using a model grass species, wheat. Compared with each of 6 surfactants used alone, a greater uptake enhancement was observed when an aliphatic amine surfactant of higher ethylene oxide (EO) content was mixed with either a linear alcohol or an octylphenol non-ionic surfactant of lower EO content, at equivalent concentration. Surfactant ratio in a mixture was also important in the case of one combination. Three of the positive surfactant combinations were also tested on barnyard grass and their synergistic effect on glyphosate uptake was confirmed. The performance of one of the best surfactant combinations was further compared with a commercial glyphosate formulation by measuring the uptake rate of glyphosate into both wheat and ryegrass plants over a 24-h period. The surfactant mixture provided much faster uptake into both species and also significantly higher overall uptake into ryegrass. Whereas ammonium sulfate could also improve glyphosate uptake into wheat when used at high concentrations and in combination with certain non-ionic surfactants, the enhancing effect of a humectant, glycerol, on uptake was of much lower magnitude and observed only in the presence of super-spreading surfactants. The practical value of using surfactant mixtures is discussed.
Changes in the composition and size distribution of endosperm proteins from bug-damaged wheats
Authors: Sivri D. , Batey I. L. , Skylas D. J. , Daqiq L. , Wrigley C. W.
Published: April 2004

In this study, grain that had been damaged by the bug Eurygaster spp. and/or Aelia spp., plus some undamaged grain, was selected from hard red winter (HRW) wheat. The changes in endosperm proteins were determined by 2-dimensional (2-D) electrophoresis and size-exclusion high-performance liquid chromatography (SE-HPLC). Although some new protein spots and a slight decrease in the staining intensities of some polypeptides were observed in the 2-D map of the bug-damaged sample, other parts of the gels were similar to the sound (control) sample in terms of relative mobilities and intensities of the polypeptide spots. The major difference between bug-damaged and control samples was that a group of polypeptides, presumably HMW-glutenins, shifted to a more basic region of the map. The SE-HPLC patterns of the total proteins extracted from control and bug-damaged samples in SDS-buffer showed that they differed in the size distribution of the polymeric glutenin protein and in their glutenin/gliadin ratios. The solubility of proteins in SDS buffer was greater in the bug-damaged sample. The 'unextractable' polymeric protein (only extractable in SDS-buffer after sonication) (UPP %) was significantly lower in the bug-damaged sample than in the control. The results of 2-D analysis and the decline in the quantity of unextractable proteins in SDS buffer suggest that bug-protease causes dough weakening by degradation of polymeric glutenin, presumably by hydrolysis, and possibly other mechanisms that affect the aggregation of the gluten molecules.
Phalaris aquatica L. (phalaris) breeding line PX22: a source of resistance to Mediterranean rusts (Puccinia spp.)
Authors: Oram R. N. , Putievsky E.
Published: April 2004

A variable breeding population of phalaris has been developed; it is resistant to stem and leaf rusts that attack Australian phalaris cultivars in Israel but that are not yet present in Australia. The population also is seed retaining and low in tryptatmine alkaloids. Seed is stored at CSIRO, Canberra.
Insights into the policy and practice of teacher education in low‐income countries: the multi‐site teacher education research project
Authors: Lewin Keith M. , Stuart Janet M.
Published: April 2004

Abstract The Multi‐Site Teacher Education Research project (MUSTER) explores initial teacher education in five countries—Ghana, Lesotho, Malawi, South Africa, and Trinidad and Tobago. National research teams collected and analysed data on key dimensions of the training process, which included the characteristics of those selected for training, the curriculum processes they experience, the outcomes of training, the reflections of newly trained teachers in schools, analysis of supply and demand for new teachers, and projections of the resource and cost implications of meeting national targets to universalise primary schooling. Many insights are contained in the extensive publications associated with the project, and these lead to a variety of evidenced‐based conclusions that will inform future policy.
Belief Bias and Figural Bias in Syllogistic Reasoning
Authors: Morley (née Lambell) Nicola J. , Evans Jonathan St. B. T. , Handley Simon J.
Published: April 2004

Belief bias is the tendency to be influenced by the believability of the conclusion when attempting to solve a syllogistic reasoning problem. Figural bias is the tendency to be influenced by the order in which the information is presented in the premises when attempting to solve a syllogistic reasoning problem. When studied simultaneously they enable an investigation of whether participants’ reasoning on the syllogistic reasoning task is guided by the conclusion (backward reasoning) or the premises (forward reasoning). Experiments 1 and 2 found evidence of belief bias but not figural bias on the syllogistic evaluation task paradigm. Experiments 3 and 4 found evidence of figural bias but not belief bias on the syllogistic production task paradigm. The findings highlight that different task characteristics influence performance dependent upon the nature of task presentation. These findings are discussed in the context of current theories of belief bias in syllogistic reasoning.
Illusory Recollection and Dual–Process Models of Recognition Memory
Authors: Higham Philip A. , Vokey John R.
Published: April 2004

Higham and Vokey (2000, Exps.1 & 3)demonstrated that a slight increase in the display duration of a briefly presented word prior to displaying it in the clear for a recognition response increased the bias to respond “old”. In the current research, three experiments investigated the phenomenology associated with this illusion of memory using the standard remember–know procedure and a new, independent–scales methodology. Contrary to expectations based on the fluency heuristic, which predicts effects of display duration on subjective familiarity only, the results indicated that the illusion was reported as both familiarity and recollection. Furthermore, manipulations of prime duration induced reports of false recollection in all experiments. The results—in particular, the implications of illusory recollection—are discussed in terms of dual–process, fuzzy–trace, two–criteria signal detection models and attribution models of recognition memory.
Competition in the Business Services Sector: Implications for the Competitiveness of the European Economy
Authors: Roberts Joanne
Published: April 2004

This paper investigates the nature and extent of competition in the European business services sector. Levels of competition in the sector vary considerably by market segment and location. A number of factors, including the fragmented nature of the market, firm based strategies and regulatory conditions, restrict competition in the sector. The analysis of competition in the business services sector highlights the failure of the market to promote consistently an efficient and quality provision of business services. Given the important role of business services in the economy as a whole and their impact on the competitiveness of client firms, it is argued here that policymakers would be wise to influence competition within the business services sector through a variety of initiatives, with the aim of improving the efficiency and quality of business services provision. Such initiatives would result in positive spill-over effects for Europe's general competitive position in the global economy.
Risk-Assessment Implications of Mechanistic Model's Prediction of Low-Dose Nonlinearity of Liver Tumor Risk for Mice FED Fumonisin B1
Authors: Kodell Ralph L. , Turturro Angelo
Published: April 2004

A two-stage, clonal-expansion model of liver tumor risk in mice was developed by Kodell et al. (Food Addit Contam 18:237–253, 2001) based on the hypothesis that fumonisin B1, a naturally occurring mycotoxin in corn, is not genotoxic, but rather causes cancer through the disruption of sphingolipid metabolism. This disruption is assumed to cause an increase in apoptosis, in response to which cells proliferate to compensate for reduced tissue mass. The resulting differential increase in the number of pre-neoplastic cells at risk of mutation during cell division is assumed to lead to an increase in the incidence of tumors. Two-year liver tumor incidences predicted by the model using data on organ weight, cell proliferation, and sphingolipid metabolism provided a reasonable match to the actual 2-year observed incidences in a study conducted at the National Center for Toxicological Research. The predictions indicated no risk at low doses (even a possible hormetic effect) and high risk at high doses in females, as well as a complete absence of a dose response (or perhaps, a hormetic effect) in males. This paper provides a commentary on the risk-assessment implications of the modeling results, pointing out that the model's low-dose predictions provide scientific support and justification for the U.S. Food and Drug Administration's low-ppm guidance levels in corn products. These guidance levels are significantly higher than would be obtained using linear extrapolation, the method most often used for genotoxic carcinogens and other carcinogens for which low-dose linearity cannot be ruled out.
Study on inhibitive mechanisms of molybdate used in combination with phosphate in neutral environments
Authors: Yuchun Li , Xunjie Gong , Keru Peng , Yunbo Luo
Published: April 2004

The conjoint effect of the binary inhibitors molybdate and phosphate on Type A20 carbon steel has been studied, using electrochemical measurement tests. The compatibility between molybdate and phosphate can achieve synergistic benefits, and the inhibitive mechanism was investigated.
Working with Gordon Pask: some personal impressions
Authors: Elstob Michael
Published: April 2004

Gives some personal impressions about Gordon from the author’s time working for him at System Research Ltd and from time working together in the Department of Cybernetics, Brunel University.
Supporting virtual learning groups. Part 2: an integrated approach
Authors: McFadzean Elspeth
Published: April 2004

The learning industry and business educational establishments are being transformed by the use of the virtual learning environment. This enables learners to participate and collaborate from all corners of the earth at any time of the day. In addition, costs can be shared over multiple sites and learning materials can be more easily kept up to date. This paper discusses five different approaches to developing, supporting and participating in the learning environment. These are the pedagogical approach, the intellectual approach, the technical approach, the collaborative approach and the facilitative approach. From these approaches, an integrated model of virtual learning is developed. Finally a number of recommendations are presented.
Reviewing local screening policies – a worthwhile exercise?
Authors: Thornton‐Jones Helen , Hampshaw Susan , Soltan Hora , Madhok Rajan
Published: April 2004

Reviews antenatal and early childhood screening programmes to assess the impact of guidance from the National Screening Committee (NSC). Develops methods to investigate local practice (questionnaires and telephone interviews) and summarises best practice guidance from authoritative sources. Reviews 23 antenatal and 15 early childhood programmes, of which 22 and eight respectively are in place locally. Different types of authoritative sources varied in the aspect of screening on which they commented. Guidance from authoritative sources differed and local practice variations reflected this. In three programmes these variations needed to be addressed. Elsewhere, the NSC’s “watch and wait” stance was confirmed. Limitations to local quality assurance were also identified. Programmes are for the most part following authoritative guidance, but variations in authoritative guidance are a significant issue. Robust audit is required to ensure that the local programmes are achieving optimal health gain.
Developing strategic leadership of clinical governance through a programme for NHS boards
Authors: Boggust Marilyn , Deighan Michael , Cullen Ron , Halligan Aidan
Published: April 2004

National Health Service trust boards are constantly challenged to achieve a balance between their resources and meeting the needs of the communities they serve. In addition, the scientific, technological, political and economic factors, which influence health and social care, are driving change more rapidly than ever before in the Health Service. As part of its function to support NHS organisations with the implementation of clinical governance, the NHS Clinical Governance Support Team (CGST) has developed a strategic development programme for trust boards. The aim of the programme is to develop the board’s capability to meet its responsibilities for governance and the delivery of safe, high quality patient care.
An investigation of the perceived importance and effectiveness of quality management approaches
Authors: Sharma Bishnu , Gadenne David
Published: April 2004

Investigates the key strategic approaches used by Queensland businesses in achieving their quality objectives. Finds that the highest ranked quality management techniques of total sample firms included a program for reduction in defects, commitment and communication of commitment to quality programs, an open trusting culture and interaction with customers and suppliers. Finds also that in excess of 65 per cent of Queensland businesses adopt some form of quality management techniques, of which ISO 9000 was found to be dominant. Quality management approaches used by businesses committed to quality management were compared with those which had no formal commitment to quality management. The results suggest that businesses committed to a quality management program are more inclined to have top executive support for, and organisational communication of, quality management principles, plus greater emphasis on better customer relationships, and that these quality management approaches are positively associated with organisational performance.
Girls Rock, Boys Roll: An Analysis of the Age 14–16 Gender Gap in English Schools
Authors: Burgess Simon , McConnell Brendon , Propper Carol , Wilson Deborah
Published: April 2004

We investigate possible explanations for the educational gender gap at age 16. We employ a national dataset of matched exam results of the cohort of pupils who took Key Stage 3 tests in 1999 and GCSEs in 2001. Our key result is the sheer consistency of the gender gap, across both the attainment and the ability distribution, with regard to both raw outcomes and value added. It is primarily driven by performance differentials in English. The generality of the gender gap suggests its source is not within‐school practice, which means that policy directed at improving such practice may be misplaced.
NQO1 activity in the main and the accessory olfactory systems correlates with the zonal topography of projection maps
Authors: Gussing Fredrik , Bohm Staffan
Published: April 2004

The mouse olfactory epithelium (OE) is divided into spatial zones, each containing neurons expressing zone‐specific subsets of odorant receptor genes. Likewise, the vomeronasal (VN) organ is organized into apical and basal subpopulations of neurons expressing different VN receptor gene families. Axons projecting from the different OE zones and VN subpopulations form synapses within circumscribed regions in the glomerular layer of the olfactory bulb (OB) and accessory olfactory bulb (AOB), respectively. We here show that mature neurons in one defined zone selectively express NADPH:quinone oxidoreductase (NQO1), an enzyme that catalyses reduction of quinones. Immunohistochemistry and in situ hybridization analyses show non‐overlapping expression of NQO1 and the Rb8 neural cell adhesion molecule (RNCAM/OCAM) in OE and axon terminals within glomeruli of the OB. In addition, NQO1 immunoreactivity reveals selective, zone‐specific axon fasciculation in the olfactory nerve. VN subpopulations do not show complementary patterns of RNCAM and NQO1 immunoreactivity, instead both genes are co‐expressed in apical VN neurons that project to the rostral AOB. These results indicate that one division of both the accessory and the main olfactory projection maps are composed of sensory neurons that are specialized to reduce environmental and/or endogenously produced quinones via an NQO1‐dependent mechanism. The role of NQO1 in bioactivation of quinoidal drugs also points to a connection between zone‐specific NQO1 expression and zone‐specific toxicity of certain olfactory toxins.
Endogenous adenosine modulates epileptiform activity in rat hippocampus in a receptor subtype‐dependent manner
Authors: Etherington Lori‐An V. , Frenguelli Bruno G.
Published: April 2004

The purine nucleoside adenosine is released during seizure activity and exerts an anticonvulsant influence through inhibition of glutamate release and hyperpolarization of neurons via adenosine A1 receptors. However, activation of adenosine A2A and A3 receptors may counteract the inhibitory effects of A1 receptors. We have therefore examined the extent to which endogenous adenosine released during seizure activity activates the different adenosine receptor subtypes and the implications for seizure activity in the rat hippocampus in vitro. Brief trains of high‐frequency stimulation in nominally Mg2+‐free artificial cerebrospinal fluid evoked epileptiform activity and resulted in a transient depression of the simultaneously recorded CA1 field excitatory postsynaptic potential. In the presence of 8‐cyclopentyl‐1,3‐dimethylxanthine (CPT), an adenosine A1 receptor antagonist, the occurrence of spontaneous seizure activity was greatly increased as was the duration and intensity of evoked seizures, whilst the postictal depression of basal synaptic transmission was greatly attenuated. Application of ZM 241385, an adenosine A2A receptor antagonist, shortened the duration of epileptiform activity, whereas administration of MRS 1191, an adenosine A3 receptor antagonist, both decreased the duration and intensity of seizures. Combined application of the A2A and A3 receptor antagonists also resulted in a reduction in seizure duration and intensity. However, no evidence was found for a role for protein kinase C in the regulation of seizure activity by endogenous adenosine. Our data confirm the dominant anticonvulsant role that endogenous and tonic adenosine play via the A1 receptor, and suggest that the additional adenosine receptor subtypes may compromise this anticonvulsant property through promotion of seizure activity.
The Type IV phosphodiesterase inhibitor rolipram interferes with drug‐induced conditioned place preference but not immediate early gene induction in mice
Authors: Thompson Barbara E. , Sachs Benjamin D. , Kantak Kathleen M. , Cherry James A.
Published: April 2004

Behavioural effects of psychostimulant and opiate drugs are mediated in part by cAMP pathways operating in the nucleus accumbens. Degradation of cAMP occurs through the action of phosphodiesterases, such as the Type IV phosphodiesterases (PDE4s) that are found throughout the brain. To examine the potential role of PDE4 in reward‐mediated behaviour, we measured the effects of rolipram, a PDE4 selective inhibitor, on cocaine (18 mg/kg i.p.) and morphine (5 mg/kg s.c.) conditioned place preference in Swiss Webster mice. Rolipram (0, 0.2 or 1.0 mg/kg i.p.) given 30 min prior to drug administration dose‐dependently reduced conditioning due to both cocaine and morphine. However, rolipram did not affect place preference induced by food, nor did it prevent the expression of a previously established place preference conditioned by cocaine or morphine. In a second experiment, rolipram administered 30 min prior to a single cocaine injection (50 mg/kg i.p.), did not alter cocaine‐induced c‐Fos expression in the caudate putamen or nucleus accumbens core. However, rolipram, but not cocaine, induced c‐Fos in the nucleus accumbens shell. These results indicate that elevation of cAMP in neurons that express PDE4s may attenuate the rewarding properties of cocaine and morphine, but does not alter the cocaine signalling cascade that induces c‐Fos expression. Thus, PDE4‐mediated regulation of cAMP levels could underlie the establishment of reward valence to abused drugs.
Strong impact of highly active antiretroviral therapy on survival in patients with human immunodeficiency virus‐associated Hodgkin's disease
Authors: Hoffmann Christian , Chow Kai Uwe , Wolf Eva , Faetkenheuer Gerd , Stellbrink Hans‐Juergen , van Lunzen Jan , Jaeger Hans , Stoehr Albrecht , Plettenberg Andreas , Wasmuth Jan‐Christian , Rockstroh Juergen , Mosthaf Franz , Horst Heinz‐August , Brodt Hans‐Reinhard
Published: April 2004

Hodgkin's disease (HD) is the most common non‐acquired immunodeficiency syndrome (AIDS)‐defining malignancy in human immunodeficiency virus (HIV)‐infected patients. We analysed the outcome of patients with HIV‐associated HD (HIV‐HD) with respect to the use and efficacy of highly active antiretroviral therapy (HAART) and other prognostic factors. To evaluate the effects of several variables on overall survival (OS), Kaplan–Meier statistics and extended Cox regression analysis were performed. Response to HAART was used as a time‐dependent variable and was defined as an increase of >0·1 × 109 CD4 cells/l and/or at least one viral load <500 copies/ml during the first 2 years following diagnosis of HIV‐HD. Fifty‐seven patients with HIV‐HD diagnosed between 1990 and 2002 were included in the study. In the Cox model, the only factors independently associated with OS were HAART response [relative hazard (RH) 0·19; 95% confidence interval (CI) 0·06–0·60], complete remission (RH 0·30, 95% CI 0·13–0·72), and age 45 years (RH 0·23; 95% CI 0·09–0·60). Median survival time in patients without HAART response was 18·6 months, whereas the median survival time in patients with HAART response was not reached (89% OS at 24 months). In this cohort, a significant improvement in survival was found in patients with HIV‐HD who responded to HAART.
Changes in haemoglobin during interferon alpha‐2b plus ribavirin combination therapy for chronic hepatitis C virus infection
Authors: Sulkowski M. S. , Wasserman R. , Brooks L. , Ball L. , Gish R.
Published: April 2004

Interferon alpha and ribavirin (RBV) combination therapy is associated with decreases in haemoglobin (Hb) concentrations and anaemia. The aim of this analysis was to better characterize the magnitude and frequency of Hb changes and risk factors. This retrospective analysis evaluated treatment‐related changes in Hb in 677 patients who participated in either of two interferon alpha‐2b plus RBV studies for chronic hepatitis C virus (HCV) infection. Study 1 included 192 interferon alpha‐naïve patients randomized to receive RBV 1000–1200 mg/day plus interferon alpha‐2b 3 million IU daily or three times weekly for 48 weeks. Study 2 included 485 interferon alpha‐experienced patients randomized to receive RBV 1000‐1200 mg daily plus interferon alpha‐2b 3 million IU daily or three times weekly for 4 weeks, followed by three times weekly dosing for 44 weeks. More than 50% of all patients experienced a decrease in Hb ≥30 g/L. Women were 4.4 times as likely as men to experience a Hb level of <100 g/L; however, men were at a 40% higher risk to experience a Hb decline of >30 g/L from baseline. Daily use of interferon alpha‐2b did not impact the magnitude of Hb decrease. In this pooled analysis, RBV dose reduction resulted in increases in Hb concentration of approximately 10 g/L. Lower baseline creatinine clearance, higher baseline Hb levels and increased age were independently associated with increased risk of Hb decreases of >27.7%. Lower baseline weight was not associated with increased risk of Hb decrease. Substantial Hb decreases occur frequently with interferon alpha/RBV combination therapy. Sex, the magnitude of the Hb decline and renal function are potentially important factors to consider in patients receiving RBV. Further research is needed to determine the impact on virological response and to develop strategies to manage the medical consequences.
Immunohistochemistry for the detection of swine hepatitis E virus in the liver
Authors: Ha S.‐K. , Chae C.
Published: April 2004

Summary.  Swine hepatitis E virus (HEV) antigen was detected immunohistochemically in formalin‐fixed, paraffin‐embedded hepatic tissue from 30 naturally infected pigs. Thirty pigs from 30 different herds were selected on the basis of positive results for reverse transcription‐polymerase chain reaction. Positive cells typically exhibited a red reaction product in the cytoplasm without any observable background staining. Swine HEV antigen was consistently detected in liver from all 30 pigs tested. A strong immunohistochemical signal was seen within a variable number of hepatocytes in multifocal lobules. The signal involved the majority of hepatocytes diffusely or was confined to foci of liver cells. Positive immunohistochemical signals were also detected in small and large intestine, lymph node, tonsil, spleen, and kidney. The immunohistochemistry technique developed in this study proved useful for the detection of swine HEV in formalin‐fixed, paraffin‐embedded tissues taken from naturally infected pigs and may be a valuable tool in studying the pathogenesis of swine HEV infection.
Role of oxidative stress and the antioxidant network in cutaneous carcinogenesis
Authors: Sander Christina S. , Chang Hong , Hamm Florian , Elsner Peter , Thiele Jens J.
Published: April 2004

Melanoma and nonmelanoma skin cancers are among the most prevalent cancers in the human population. Solar ultraviolet radiation is considered a major etiological factor but the relationship between dose, timing, and nature of exposure to tumor development is still unclear. Free radicals are generated by normal physiologic processes, including aerobic metabolism and inflammatory response, but may inflict cellular damage when generation is increased and antioxidant defense mechanisms are overwhelmed. Important findings supporting the free radical hypothesis in skin carcinogenesis are: (1) Reactive oxygen species (ROS) are generated in UVA‐ and UVB‐irradiated skin in excessive doses, (2) the natural cutaneous antioxidant defense is impaired upon UV‐exposure, (3) free radicals are involved in all steps of carcinogenesis, (4) supplementation with antioxidants can inhibit skin carcinogenesis, and (5) conditions that increase ROS generation enhance photocarcinogenesis. These findings provide a promising rationale for the development of powerful new antioxidant strategies in the prevention and therapy of skin cancer.
Agreement between prostate cancer patients and their clinicians about utilities and attribute importance
Authors: Elstein Arthur S. , Chapman Gretchen B. , Chmiel Joan S. , Knight Sara J. , Chan Cheeling , Nadler Robert B. , Kuzel Timothy M. , Siston Amy K. , Bennett Charles L.
Published: April 2004

Purpose  To examine the agreement between prostate cancer patients’ utilities for selected health states and their rankings of the importance of six attributes of the health states and the clinicians’ judgements of what would be in the patients’ best interests.

Method  Patients with newly diagnosed localized prostate cancer individually completed a time trade‐off utility assessment shortly after being diagnosed. The health states evaluated were constructed from a multi‐attribute utility model that incorporated six aspects of living with the disease and outcomes of treatment. Each patient assessed his current health state and three hypothetical states that might occur in the future, and provided rankings of the importance of the six attributes. The clinicians caring for each patient independently provided their views of what utilities and importance rankings would be in the patient's best interest.

Results  The across‐participant correlations between patients’ and clinicians’ utilities were very low and not statistically significant. Across‐participant correlations between patient and clinician importance rankings for the six attributes were also low. Across‐health state and across‐attribute correlations between utilities or importance rankings were highly variable across patient–clinician pairs.

Conclusion  In the clinical settings studied, there is not a strong relationship between valuations of current and possible future health states by patients with newly diagnosed prostate cancer and their clinicians. Implications of these results for substituted judgement, when clinicians advise their patients or recommend a treatment strategy, are discussed.
The feasibility of neuropsychological endophenotypes in the search for genes associated with bipolar affective disorder
Authors: Glahn David C , Bearden Carrie E , Niendam Tara A , Escamilla Michael A
Published: April 2004

Objective:  Efforts to identify genetic loci for bipolar disorder (BPD) have thus far proved elusive. The identification of processes mediating between genotype and phenotype (endophenotypes) may help resolve the carrier status of family members in genetic studies of polygenetic disorders with imperfect penetrance, such as BPD. We reviewed the literature to determine if neuropsychological measures could be used as effective endophenotypes to aid molecular genetic studies searching for genes predisposing to BPD.

Methods:  Four prerequisites for endophenotypic markers are described, and a critical review of relevant literature was undertaken to determine if neurocognitive measures satisfy these four requirements in BPD.

Results:  We found evidence that executive functions and declarative memory may be candidate neurocognitive endophenotypes for BPD. However, we cannot exclude other areas of cognition as being affected by BPD susceptibility genes, given the limits of the current knowledge of the neuropsychology of BPD. In particular, the paucity of studies measuring cognition in healthy relatives of BPD patient limits conclusion regarding familial aggregation of particular neurocognitive deficits (i.e. attention). Furthermore, the effects of clinical state and/or medication usage on cognitive functioning in BPD probands should be further explored.

Conclusions:  Molecular genetic studies of BPD may benefit from the application of select neuropsychological measures as endophenotypic markers. The use of these markers, once defined, may improve power for detecting genes predisposing to BPD and may help to better define diagnostic criteria.
Unions and Workplace Closure in Britain, 1990–1998
Authors: Bryson Alex
Published: April 2004

This paper assesses union effects on workplace closure in the private sector in Britain between 1990 and 1998 using panel data from the 1990–98 Workplace Employee Relations Survey. On average, unions raised the chances of workplace closure in Britain in the 1990s, in contrast to the 1980s. However, the size and statistical significance of union effects differ across dimensions of unionization and type of workplace. Furthermore, the results are sensitive to the definition of workplace closure.
The New Generation of Trade Union Leaders and Prospects for Union Revitalization
Authors: Charlwood Andy
Published: April 2004

The year 2003 was widely perceived as the year of the ‘awkward squad’— a group of recently elected union leaders more prepared than their predecessors to challenge New Labour. It was also a year in which unions were perceived to have experienced the beginnings of a recovery. In this review I argue that both of these perceptions are misplaced. The new generation of union leaders are a more disparate bunch than the ‘awkward squad’ label implies. The unions they lead remain seriously weakened by a harsh and inhospitable environment. Union recovery is unlikely unless the environment changes or the new union leaders can succeed against the odds in changing the environment through political activity.
Do Accruals Drive Firm‐Level Stock Returns? A Variance Decomposition Analysis
Authors: Callen Jeffrey L. , Segal Dan
Published: April 2004

This paper extends the variance decomposition framework of Campbell [1991], Campbell and Ammer [1993], and Vuolteenaho [2002] to address the relative value relevance of accrual news, cash flow news, and expected‐return news in driving firm‐level equity returns. The extension is based on the Feltham‐Ohlson [1995, 1996] clean surplus relations. Using three models, this study shows that all three factors, accruals, cash flows, and expected future discount rates are value relevant. Moreover, accrual news is found to significantly dominate expected‐return news in driving firm‐level stock returns. Operating income news is also found to significantly dominate both expected‐return news and free cash flow news in driving firm‐level stock returns. Furthermore, after splitting net income into cash flow and accrual earnings components in the Vuolteenaho model, accrual earnings news and cash flow earnings news are found to equally drive firm‐level stock returns and to dominate expected‐return news. Further disaggregation of the data yields some evidence that accrual earnings news is a more important factor than cash flow earnings news in driving current stock returns. Overall, the three models indicate that changes in expected future accruals are a primary driver, if not the primary driver, of current stock returns.
Total Hip Arthroplasty in Nine Canine Hind Limb Amputees: A Retrospective Study
Authors: Preston Chris A. , Schulz Kurt S. , Vasseur Philip B.
Published: April 2004

ObjectiveTo determine the outcome of total hip arthroplasty in canine hindlimb amputees.

Study DesignRetrospective evaluation of clinical cases.

MethodsData recorded from the medical records of nine dogs included patient signalment, indication for amputation and total hip arthroplasty (THA), interval between amputation and THA, and surgical complications. Radiographs were used to assess implant orientation and evidence of complications. Functional outcome was assessed using direct patient evaluation by one of the authors or primary surgeons, or through telephone interview between the primary author and the owner.

ResultsSeven dogs ultimately had a good or excellent clinical results. Complications occurred in five dogs. Four dogs luxated the prosthetic joint without an obvious traumatic event within 9 weeks of the initial surgery. Revision surgeries resulted in successful coxofemoral reduction in three of four dogs. There were no clinical or radiographic findings suggestive of implant loosening or infection.

ConclusionTHA can be a successful salvage procedure in the canine hindlimb amputee with disabling, non‐neoplastic, noninfectious coxofemoral disease. The risk of luxation in the early postoperative period is high and revision surgery is required for stabilization.

Clinical RelevanceTHA is a successful procedure in the canine hindlimb amputee, however the incidence of complications is high.