bluuebunny/crossref_metadata_2025 huggingface dataset:
RhoGDI-3, a promising system to investigate the regulatory function of rhoGDIs: uncoupling of inhibitory and shuttling functions of rhoGDIs
Authors: Dransart E. , Morin A. , Cherfils J. , Olofsson B.
Published: August 2005

rhoGDIs (Rho GDP dissociation inhibitors) are postulated to regulate the activity and the localization of small G-proteins of the Rho family by a shuttling process involving extraction of Rho from donor membranes, formation of inhibitory cytosolic rhoGDI/Rho complexes, and delivery of Rho to target membranes. However, the role of rhoGDIs in site-specific membrane targeting or extraction of Rho is still poorly understood. We investigated here the in vivo functions of two mammalian rhoGDIs: the specific rhoGDI-3 and the well-studied rhoGDI-1 (rhoGDI) after structure-based mutagenesis. We identified two sites in rhoGDIs, forming conserved interactions with their Rho target, whose mutation results in the uncoupling of inhibitory and shuttling functions of rhoGDIs in vivo. Remarkably, these rhoGDI mutants were detected at Rho-induced membrane ruffles or protrusions, where they co-localized with RhoG or Cdc42, probably identifying for the first time the site of extraction of a Rho protein by a rhoGDI in vivo. We propose that these mutations act by modifying the steady-state kinetics of the shuttling process regulated by rhoGDIs, such that transient steps at the cell membranes now become detectable. They should provide valuable tools for future investigations of the dynamics of membrane extraction or delivery of Rho proteins and their regulation by cellular partners.
A model for Rab GTPase localization
Authors: Pfeffer S.
Published: August 2005

The human genome encodes almost 70 Rab GTPases. These proteins are C-terminally geranylgeranylated and are localized to the surfaces of distinct membrane-bound compartments in eukaryotic cells. This mini review presents a working model for how Rabs achieve and maintain their steady-state localizations. Data from a number of laboratories suggest that Rabs participate in the generation of macromolecular assemblies that generate functional microdomains within a given membrane compartment. Our data suggest that these complex interactions are important for the cellular localization of Rab proteins at steady state.
Use of the Ras binding domain of c-Raf for biochemical and live-cell analysis of Ras activation
Authors: Rubio I.
Published: August 2005

Small modular GBDs (GTPase-binding domains) derived from GTPase-effector proteins are useful tools for the selective detection of the active GTP-loaded GTPase conformation, be it in biochemical assays or for imaging purposes. Use of GBD probes requires careful consideration of all features of the GDB–GTPase interaction. It is innate to the strong and specific interaction with the GTP-loaded GTPase, that GBDs will protect their partner GTPases from GAP (GTPase-activating protein) action. This feature is likely to cause an increase in cellular Ras-GTP levels, in particular in leucocytes and other cells with high steady-state Ras-GDP/GTP cycling rates. By the same token, high levels of GBD expression will interrupt GTPase-initiated signalling, with implications for the activation of the very same GTPase since feedback regulatory mechanisms can impinge on this process.
Studying the consequences of immediate loss of gene function in the intestine: APC
Authors: Clarke A.R.
Published: August 2005

The use of mouse models to study neoplasia is proving particularly powerful in dissecting the mechanisms underlying disease initiation and progression. However, the majority of these models have been somewhat limited in studying the very early effects of loss of gene function, as tumour initiation relies upon either constitutive loss of gene function or spontaneous somatic loss of function. We have therefore adopted a strategy of using an inducible Cre-lox-based system to analyse the effects of loss of gene function, the use of which is reviewed here for the intestinal tumour suppressor APC (adenomatous polyposis coli). Using this approach, we have conditionally and synchronously inactivated APC in virtually all the epithelial cells of the adult murine small intestine. After 5 days following induction of Cre-mediated recombination, mice show grossly altered crypt/villus architecture. Deficiency in APC perturbs migration, alters the normal programme of differentiation and results in increased proliferation and apoptosis. Microarray analysis reveals the transcriptome to be significantly altered; reflecting both gross phenotypic changes and changes in transcriptional activation. These findings demonstrate that APC is indeed the critical determinant of cell fate in the intestinal epithelium, explaining its role as the cellular ‘gatekeeper’ in preventing neoplasia.
MutYH (MYH) and colorectal cancer
Authors: Sampson J.R. , Jones S. , Dolwani S. , Cheadle J.P.
Published: August 2005

MAP (MutYH-associated polyposis) is a recently described colorectal adenoma and carcinoma predisposition syndrome that is associated with biallelic-inherited mutations of the human MutY homologue gene, MutYH. MutYH is often also termed MYH. MAP tumours display a mutational signature of somatic guanine-to-thymine transversion mutations in the adenomatous polyposis coli and K-ras genes, reflecting the normal role of MutYH in the base excision repair of adenines misincorporated opposite 7,8-dihydro-8-oxoguanine, a prevalent and stable product of oxidative damage to DNA. However, the full genetic pathway of MAP tumorigenesis has not been elucidated.
Epigenetic events in the colorectum and in colon cancer
Authors: Grady W.M.
Published: August 2005

Colon cancers arise from benign neoplasms and evolve into adenocarcinomas through a stepwise histological progression sequence, proceeding from either adenomas or hyperplastic polyps/serrated adenomas. Genetic alterations have been associated with specific steps in this polyp–adenocarcinoma sequence and are believed to drive the histological progression of colon cancer. Recently, epigenetic alterations, which include CGI (CpG island) DNA methylation, have been shown to occur in colon polyps and colon cancer. The aberrant methylation of genes appears to co-operate with the genetic alterations to drive the initiation and progression of colon polyps to colon cancer. CGI DNA methylation is an epigenetic mechanism that represses gene transcription in normal cellular processes, but it becomes excessive and aberrant in many neoplasms. The aberrant DNA methylation affects CpG-rich regions, called CGIs, in the 5′ region of genes and results in transcriptional silencing through effects on transcription factor binding and associated changes in chromatin structure. These hypermethylated genes are not only probable pathogenic events affecting colon-cancer formation, but also neoplasm-specific molecular events that may be useful as molecular markers for colon tumours. Furthermore, aberrant DNA methylation of tumour-suppressor genes may occur secondary to a genetic predisposition or to a field-cancerization effect in the colon and may be useful as molecular markers for the risk of developing colon cancer.
Design of a MUC1-based cancer vaccine
Authors: Hanisch F.-G.
Published: August 2005

The epithelial type 1 transmembrane mucin MUC1 is long-established as a marker for monitoring recurrence of breast cancer, and beyond its diagnostic marker qualities, it is a promising target for immunotherapeutic strategies to treat cancer by active specific immunization. The mucin is able to break tolerance and to induce humoral immune responses in healthy subjects and in cancer patients, but the response is generally weak. These natural responses to tumour-associated MUC1 glycoforms indicate that antibody reactivities are more directed to glycopeptide than to non-glycosylated peptide epitopes. To overcome the weak immunogenicity of heavily O-glycosylated MUC1, the question of whether O-linked glycans remain intact during processing in the MHC class II pathway was addressed. Attempts were made to define site-specific O-glycosylation and the structural requirements for efficient endosomal proteolysis by cathepsin L in dendritic cells. A fraction of glycopeptides survive the processing machinery, and have the capacity to bind to MHC class II and to activate sub-populations of glycopeptide-specific helper T-cell clones as a prerequisite for strong and long-lasting immune responses to MUC1-positive tumours. Moreover, studies on clusters of sequence-variant repeats, which are interspersed in the repeat domain of MUC1 at high frequency, have revealed that a limited set of concerted amino-acid replacements (Asp-Thr0-Arg1–Pro10 to Glu-Ser0-Arg1–Ala10) contributes considerably to increased peptide flexibility and to under-glycosylation of sequence-variant repeats which in concert modify immunological features of the mucin. Peptides and glycopeptides with the immunodominant DTR (Asp-Thr-Arg) or with the variant ESR (Glu-Ser-Arg) motif, and highly immunogenic peptides of the degenerate repeats that flank the repeat domain are currently evaluated as potential targets in multi-epitopic adjuvant-based vaccine strategies for their capacity to induce cytotoxic T-cell responses.
DNA damage hypersensitivity in cells lacking BRCA2: a review of in vitro and in vivo data
Authors: Hay T. , Clarke A.R.
Published: August 2005

Since the discovery of the tumour suppressor BRCA2 (encoded by breast-cancer susceptibility gene 2), cells lacking the fully functional protein have consistently been found to show increased sensitivity to a variety of DNA-damaging agents, particularly those that cross-link DNA. In this short review, we will bring together these findings and discuss them in the light of our recent in vivo data in the mouse small intestine, which suggests that deletion of cells lacking Brca2 is necessary to avoid the development of potentially tumorigenic clones in this tissue, a system that may be less effective in the mammary glands of humans with germline mutations in BRCA2.
Tetrahydrofolate biosynthesis and distribution in higher plants
Authors: Sahr T. , Ravanel S. , Rébeillé F.
Published: August 2005

One-carbon transfer reactions are mediated by H4F (tetrahydrofolate), a soluble coenzyme (vitamin B9) that is synthesized de novo by plants and microorganisms, and absorbed from the diet by animals. H4F synthesis in plants is quartered between the plastids, the cytosol and the mitochondria, a spatial distribution that is not observed in the other organisms and that suggests a complex intracellular traffic. Also, the activity of H4F synthesis fluctuates during plant growth, depending on the tissue and the developmental stage of the seedling, thus illustrating the flexibility of one-carbon metabolism in these organisms. This paper will focus on our recent knowledge about H4F synthesis in the plant cell and will briefly describe the activity of the pathway during the growth and development of the seedling.
Molecular and thermodynamic bioenergetics
Authors: Williams R.J.P.
Published: August 2005

Studies of biological sciences can be approached in two ways: reductively, as in molecular biology, or holistically, as in systems biology. In this paper, I illustrate my views on approaches to bioenergetics through the analysis of molecular energy transduction and of general thermodynamics relationships in systems biology. The future lies with the second as the first is nearing completion.
Nucleation and growth kinetics of spiral steps on TiN(111): An in situ low-energy electron microscopy study
Authors: Kodambaka S. , Bareño J. , Khare S. V. , Święch W. , Petrov I. , Greene J. E.
Published: August 2005

We use in situ low-energy electron microscopy to investigate the near-equilibrium dynamics of TiN(111) steps, pinned by surface-terminated dislocations, as a function of N2 pressure pN2 and time during annealing of TiN(111) layers at temperatures T between 1600 and 1735 K. At each T, we observe the nucleation and growth of spiral steps rotating around dislocation cores. The spirals undergo a shape-preserving motion with a constant angular velocity ω as they grow inward, normal to the surface, forming vacancy pits. We find that ω for successive spirals emanating from the same source decreases slowly with time at all pN2 values between vacuum and 5×10−7Torr. From the ω(T) data, we obtain an activation energy of 4.6±0.2eV, irrespective of pN2, for the growth of spiral steps.
Angle dependence of acoustic phonon-assisted tunneling in a weakly coupled superlattice: Evidence for terahertz phonon amplification
Authors: Kini R. N. , Kent A. J. , Stanton N. M. , Henini M.
Published: August 2005

We investigate nonequilibrium acoustic phonon-assisted tunneling in a weakly coupled GaAs∕AlAs superlattice (SL). Previously it had been predicted that, in such structures, the conditions for terahertz acoustic phonon amplification can be achieved [B. A. Glavin, V. A. Kochelap, and T. L. Linnik, Appl. Phys. Lett. 74, 3525 (1999)]. We present experimental measurements of the change in current ΔI due to an incident nonequilibrium phonon pulse generated by thermalizing a laser pulse in a metal film. In particular, we measure the dependence on the angle of incidence θ of the phonons relative to the SL growth direction. The results are compared with numerical calculations made using the two-well model. It is found that good agreement between the measurements and calculations can be obtained for all θ if we assume that amplification is occurring for phonons propagating in a direction near θ=0. Due to the amplification of phonons with energy ℏωq≲Δ, where Δ is the energy drop per period of the SL, the nonequilibrium phonon distribution in the vicinity of the SL is different from the expected Planck spectrum of the phonon source. We show that this can explain the experimental measurements of ΔI at θ=0. We present these results as evidence for phonon amplification in the 400-GHz–1-THz frequency range.
Decomposition of the spatially filtered and ensemble averaged kinetic energy, the associated fluxes and scaling trends in a rotor wake
Authors: Chow Yi-Chih , Uzol Oguz , Katz Joseph , Meneveau Charles
Published: August 2005

Particle image velocimetry data obtained in the rotor wake of a turbomachine are used for examining elements of the ensemble averaged and spatially filtered kinetic energy. These two distinct averaging processes decompose the kinetic energy into four parts, consisting of the mean-flow resolved, mean-flow subgrid, fluctuating resolved, and fluctuating subgrid parts. Their evolution equations include energy flux terms among these parts. The results elucidate the fundamental difference between the filtered turbulence (Reynolds) production and the ensemble averaged subgrid scale (SGS) dissipation rates. Each of these terms consist of three energy fluxes, but only one of them is common to both, the flux from the mean-flow resolved to the fluctuating subgrid kinetic energy parts. The other two elements of the SGS dissipation are the fluxes from the mean-flow resolved to the mean-flow subgrid parts and the fluctuating resolved to the fluctuating subgrid parts. Likewise, the other two contributions to the turbulence production are the fluxes from the mean-flow resolved to the fluctuating resolved parts and the mean-flow subgrid to the fluctuating subgrid parts. In order to examine the decay rates of the kinetic energy parts throughout the rotor wake, a new method for determining the scaling parameters is introduced. The mean-flow resolved and subgrid parts scale with the modified velocity defect squared, but the decay rates of the turbulence parts are slower.
Backtracking of a sphere slowing down in a viscous compressible fluid
Authors: Felderhof B. U.
Published: August 2005

It is shown on the basis of the linearized Navier–Stokes equations that a sphere set in motion by a sudden impulse, and slowing down in a viscous compressible fluid, can temporarily reverse its velocity at a late stage of the motion before finally slowing down with a positive velocity. For the effect to occur, the fluid needs to be sufficiently compressible, and the bulk viscosity needs to be sufficiently small relative to the shear viscosity. More generally, the velocity decays nonmonotonically, without necessarily passing through zero. The results are derived from the frequency-dependent friction coefficient, and hold for general boundary condition on the surface of the sphere.
Postdeposition thermal annealing and material stability of 75 °C hydrogenated nanocrystalline silicon plasma-enhanced chemical vapor deposition films
Authors: Lee Czang-Ho , Grant David J. , Sazonov Andrei , Nathan Arokia
Published: August 2005

This paper examines the material stability and effects of postdeposition thermal annealing of highly crystalline undoped hydrogenated nanocrystalline silicon (nc-Si:H) films prepared by conventional 13.56-MHz plasma-enhanced chemical vapor deposition at 75 °C. Electrical, structural, and chemical composition properties of the nc-Si:H films at ambient atmosphere were studied before and after the thermal annealing. The as-grown nc-Si:H films showed not only a low dark conductivity (σdark) of the order of 10−7–10−6S∕cm but also good stability after exposure to ambient atmosphere due to low oxygen concentration (CO∼2×1018atoms∕cm3) and stable hydrogen passivation of grain boundaries. On the other hand, the σdark and photoconductivity (σphoto) of the nc-Si:H films showed instability during annealing at temperatures higher than the deposition temperature and subsequent exposure to ambient atmosphere. Here, both the σdark and σphoto increased after annealing and then decreased with exposure to ambient atmosphere. In particular, the σdark decreased below the as-grown value proportional to the annealing temperature. This was not observed in nc-Si:H films which have a hydrogenated amorphous silicon nitride (a-SiN:H) passivation layer on the same time scale. There was no significant change in the microstructure of the films. However, the hydrogen concentration (CH) decreased slightly after annealing, while the CO increased. The conductivity instability is therefore strongly related to oxygen desorption and absorption due to thermal annealing and subsequent exposure to ambient atmosphere, respectively. Based on the experimental results, we propose a simple model in terms of hydrogen effusion-assisted oxygen absorption.
Laser-ablated ZnO for thin films of ZnO and MgxZn(1−x)O
Authors: Thareja R. K. , Saxena H. , Narayanan V.
Published: August 2005

We report investigations of ZnO plasma at various ambient pressures of oxygen produced by third harmonic 355nm of neodymium: yttrium aluminum garnet laser for depositing quality nanocrystalline ZnO thin films. Time- and space-resolved optical emission spectroscopy is used to correlate the plasma properties with that of the deposited thin films. The temporally resolved images of the plumes are correlated with the time-resolved emission spectrum of plasma species in the plume. The deposited films of ZnO at 100mTorr of ambient oxygen exhibited third-harmonic generation. MgxZn(1−x)O alloy thin films of different molar percentage of MgO were deposited on glass substrates with the aim of achieving variable band gap using pulsed laser deposition in 100-mTorr oxygen ambient at substrate temperatures ranging from 200to500°C. The films with x=0.1 and 0.3 exhibit single hexagonal phase with (002) as the preferred orientation, however, with x=0.5, a transition to mixed phase with hexagonal phase of (100) and cubic phase of (200) orientation is observed. The absorption edge is blueshifted with and increase of x and deposition temperature. The band gap of the deposited films increases with molar percentage and deposition temperature. The deposited films exhibited high degree of transparency (>85%) over visible range.
Structure analysis of Nd3−xYxFe23−yCo6Moy (x=0.36–3.0;y=1.1,0.9) compounds
Authors: Lv J. Y. , Han S. B. , Liu X. F. , Li X. J. , Hu Z. B. , Li J. H. , Xue Y. J. , Chen D. F.
Published: August 2005

A series of compounds Nd3−xYxFe23−yCo6Moy (x=0.36–3.0) has been synthesized and studied by x-ray powder diffraction and neutron diffraction. Rietveld analyses of the diffraction data indicate that all the compounds crystallize in A2∕m. The lattice parameters a, b, and c and unit-cell volume V decreased monotonically with the increase of Y content. Neutron-diffraction results show that Mo atoms occupy three sites, two 4i sites and one 4g site, while Co atoms are found to occupy all the Fe sites not shared with the Mo atoms. However, the most preferential sites for Co are Fe1(2c), Fe8(8j), and Fe11(4e). It is also observed that those sites preferred by Mo have the long average bond length, while sites preferred by Co have short average bond lengths.
Gold based bulk metallic glass
Authors: Schroers Jan , Lohwongwatana Boonrat , Johnson William L. , Peker Atakan
Published: August 2005

Gold-based bulk metallic glass alloys based on Au–Cu–Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5mm in the best glassformer. Au49Ag5.5Pd2.3Cu26.9Si16.3 has a liquidus temperature of 644K, a glass transition temperature of 401K, and a supercooled liquid region of 58K. The Vickers hardness of the alloys in this system is ∼350Hv, twice that of conventional 18-karat crystalline gold alloys. This combination of properties makes the alloys attractive for many applications including electronic, medical, dental, surface coating, and jewelry.
Effect of bias on indirect exchange within magnetic nanostructures
Authors: Kozub V. I. , Vinokur V.
Published: August 2005

We formulate a theory of a reversible switching of the magnetic state of magnetic multilayers embedded in the metallic nanoconstriction by the external bias. The switching is related to the effect of strongly nonequilibrium electron distribution existing in the biased nanoconstriction on the indirect exchange coupling between the magnetic layers.
Generation of Rx
+
/Pax6
+
neural retinal precursors from embryonic stem cells
Authors: Ikeda Hanako , Osakada Fumitaka , Watanabe Kiichi , Mizuseki Kenji , Haraguchi Tomoko , Miyoshi Hiroyuki , Kamiya Daisuke , Honda Yoshihito , Sasai Noriaki , Yoshimura Nagahisa , Takahashi Masayo , Sasai Yoshiki
Published: August 2005

We report directed differentiaion of retinal precursors
in vitro
from mouse ES cells. Six3
+
rostral brain progenitors are generated by culturing ES cells under serum-free suspension conditions (SFEB culture) in the presence of Wnt and Nodal antagonists (Dkk1 and LeftyA), and subsequently steered to differentiate into Rx
+
cells (16%) by treatment with activin and serum. Consistent with the characteristics of early neural retinal precursors, the induced Rx
+
cells coexpress Pax6 and the mitotic marker Ki67, but not Nestin. The ES cell-derived precursors efficiently generate cells with the photoreceptor phenotype (rhodopsin
+
, recoverin
+
) when cocultured with embryonic retinal cells. Furthermore, organotypic culture studies demonstrate the selective integration and survival of ES cell-derived cells with the photoreceptor phenotype (marker expression and morphology) in the outer nuclear layer of the retina. Taken together, ES cells treated with SFEB/Dkk1/LeftyA/serum/activin generate neural retinal precursors, which have the competence of photoreceptor differentiation.
E‐only journals: is it time to drop print?
Authors: Ware Mark
Published: August 2005

This article is a revised version of a talk given at the ALPSP seminar of the same name in February 2005. The current state of play with electronic‐only (‘e‐only’) journals is reviewed, along with some data on the different ways print and electronic editions are used. The drivers for and against a move to e‐only journals are discussed, including economic and commercial issues, long‐term access and preservation, and the growing divergence between the capabilities of print and electronic journals.
Running exercise of different duration and intensity: effect on endothelial progenitor cells in healthy subjects
Authors: Laufs Ulrich , Urhausen Axel , Werner Nikos , Scharhag Jürgen , Heitz Anja , Kissner Gerrit , Böhm Michael , Kindermann Wilfried , Nickenig Georg
Published: August 2005

Background Increased numbers of circulating endothelial progenitor cells (EPC) are associated with improved vascular function. Exercise is a central component of the primary prevention of vascular diseases. The effect of physical activity on circulating EPC in healthy individuals is not known.

Design A prospective crossover study.

Methods and results In order to study a potential link between the extent of physical exercise and progenitor cells in humans, EPC were quantified by flow cytometry and cell culture in 25 healthy volunteers undergoing three protocols of running exercise. Intensive running, defined as 30 min at 100% of the velocity of the individual anaerobic threshold (IAT; ∼82% maximal oxygen consumption; VO2max), as well as moderate running with 30 min at 80% of the velocity of the IAT (∼68% VO2max), increased circulating EPC numbers to 235±93% and 263±106% of control levels, respectively. However, moderate short-term running for 10 min did not upregulate EPC counts. The maximum increase in circulating EPC numbers was observed 10–30 min after intensive running. Exercise increased EPC migratory and colony-forming capacity.

Conclusions Intensive and moderate exercising for 30 min, but not for 10 min, increased circulating levels of EPC, which may represent an important beneficial outcome of physical exercise. The data support the notion that increased numbers of EPC correlate with cardiovascular health and suggest EPC quantification as a novel surrogate parameter of the vascular effects of exercising.
Influence of fusaric acid on phenazine-1-carboxamide synthesis and gene expression of Pseudomonas chlororaphis strain PCL1391
Authors: van Rij E. Tjeerd , Girard Geneviève , Lugtenberg Ben J. J. , Bloemberg Guido V.
Published: August 2005

Production of the antifungal metabolite phenazine-1-carboxamide (PCN) byPseudomonas chlororaphisstrain PCL1391 is essential for the suppression of tomato foot and root rot caused by the soil-borne fungusF. oxysporumf. sp.radicis-lycopersici. The authors have shown previously that fusaric acid (FA), a phytotoxin produced byFusarium oxysporum, represses the production of PCN and of the quorum-sensing signalN-hexanoyl-l-homoserine lactone (C6-HSL). Here they report that PCN repression by FA is maintained even during PCN-stimulating environmental conditions such as additional phenylalanine, additional ferric iron and a low Mg2+concentration. Constitutive expression ofphzIorphzRincreases the production of C6-HSL and abolishes the repression of PCN production by FA. Transcriptome analysis usingP. chlororaphisPCL1391 microarrays showed that FA represses expression of the phenazine biosynthetic operon (phzABCDEFGH) and of the quorum-sensing regulatory genesphzIandphzR. FA does not alter expression of the PCN regulatorsgacS,rpoSandpsrA. In conclusion, reduction of PCN levels by FA is due to direct or indirect repression ofphzRandphzI. Microarray analyses identified genes of which the expression is strongly influenced by FA. Genes highly upregulated by FA are also upregulated by iron starvation inPseudomonas aeruginosa. This remarkable overlap in the expression profile suggests an overlapping stress response to FA and iron starvation.
Sheepskin effects in Japan
Authors: Bauer Thomas K. , Dross Patrick J. , Haisken‐DeNew John P.
Published: August 2005

Purpose

The purpose of this paper is to examine the role of sheepskin effects in the return to education in Japan.

Design/methodology/approach

The paper provides a short description of the Japanese schooling and recruitment system. It then describes the data set and the empirical approach. Estimation results are presented for the various specifications. The baseline specification closely follows existing studies for the USA to facilitate comparability across the two countries. The paper further investigates whether there are significant firm‐size differences in the estimated sheepskin effects and whether sheepskin effects disappear with increasing job tenure.

Findings

The estimation results indicate that sheepskin effects explain about 50 percent of the total returns to schooling. The paper further finds that education as a signal is only important for workers in small firms with the size of these effects being similar to comparable estimates for the USA. Finally, the estimated degree effects decrease with firm tenure, in particular for small firms. These results could be explained by the particular recruitment system of large firms in Japan, which makes university diploma as a screening device unimportant for large firms and the admission policy of Japanese universities.

Originality/value

By investigating the role of sheepskin effects in a labor market that differs substantially from the labor market in the USA, the paper provides additional insights to the human capital theory‐screening hypothesis debate.
Projections of the future path of the gender wage gap in Great Britain
Authors: Shannon Michael , Kidd Michael P.
Published: August 2005

Purpose

The paper attempts to project the future trend of the gender wage gap in Great Britain up to 2031.

Design/methodology/approach

The empirical analysis utilises the British Household Panel Study Wave F together with Office for National Statistics (ONS) demographic projections. The methodology combines the ONS projections with assumptions relating to the evolution of educational attainment in order to project the future distribution of human capital skills and consequently the future size of the gender wage gap.

Findings

The analysis suggests that gender wage convergence will be slow, with little female progress by 2031 unless there is a large rise in returns to female experience.

Originality/value

The paper has projected the pattern of male and female skill acquisition together with the associated trend in wages up to 2031.
The impact of capital offering on real estate developers and construction sector stock return in Hong Kong
Authors: Chi Man Hui Eddie , Kwan Wah Wong Francis , Hung Chiang Yat
Published: August 2005

Purpose

Numerous studies suggest that announcements of capital offerings cause abnormal price reaction in stock markets. However, despite extensive research, relevant studies on the property sector are still relatively scarce, especially in the case of Hong Kong. The determinants of the post‐offering price effects, which vary across industries and regions, are yet to be identified. This paper aims to examine the abnormal stock return phenomenon of Hong Kong property developers and construction companies surrounding the announcement and offer dates of capital issuances.

Design/methodology/approach

It employs the event‐study methodology and regression analysis to verify such effects.

Findings

The major findings are: on equity offering announcements, there is a significant negative price reaction; the pre‐offering debt/equity ratio of a firm is significantly associated with the level of abnormal price reactions; and on debt offerings there is, to the contrary, a modest increase in stock prices.

Practical implications

This study has identified a set of determinants of the post‐offering stock price effects.

Originality/value

It can be concluded that there is evidence of abnormal price effects over the announcement and offer dates of capital issuances with unique characteristics of the property and construction sectors in Hong Kong.
Communication capability and attitudes toward external communication of purchasing managers in Germany
Authors: Large Rudolf O.
Published: August 2005

Purpose

Management approaches, such as supply chain management addressing cooperation among firms emphasize communication among people from different companies. The objective of this research was to investigate the impact of individual and contextual factors on the external communication behavior of purchasing managers in Germany.

Design/methodology/approach

Based on the literature, oral and written communication capabilities, purchasers' attitudes and the internal communication climate were identified as potential impact factors. A structural equation model containing 11 constructs was designed. Six hundred and seventeen responses were available for statistical analysis.

Findings

Summing up the results, oral communication capability and purchasers' attitudes toward individual communication with the suppliers play important roles in explaining external communication behavior of purchasers. Regarding indirect effects, there are strong total effects of the oral communication capability and the attitudes on the supplier management success as well as satisfaction.

Research limitations/implications

Several measures were operationalized using two‐item or three‐item scales. Future research should focus on the development of more comprehensive scales.

Practical implications

Various conclusions from the results were drawn. Particularly, there are important managerial impacts on supply management and human resource management.

Originality/value

The paper provides the first scientific insight into the relationships between oral communication capability, attitudes toward communication, communication behavior and managerial performance in the field of supply management.
Investigation of compliancy effects on the inviscid instability in fluid flow over a flat plate with heat transfer
Authors: Motsa S.S. , Sibanda P.
Published: August 2005

Purpose

A detailed investigation of the effects of surface flexibility on the inviscid instability of boundary‐layer flow over a horizontal flat plate with heat transfer when the fluid buoyancy is large is undertaken. The aim of this study is to determine whether the inviscid disturbances that arise at this limit are stabilized or destabilized by surface compliancy.

Design/methodology/approach

For large positive buoyancy numbers, the motion of the disturbances is governed by the Taylor‐Goldstein (TG) equation. Using the Chebyshev collocation spectral method, the eigen‐solutions of the TG equation are obtained and compared with known results from boundary‐layer flow over rigid flat plates.

Findings

The numerical results show that the effects of surface compliancy are important for small wave numbers and that for the inviscid modes, increasing surface parameters has the effect of destabilizing the flow. For large compliancy parameters the flow structure is indistinguishable from that which obtains in boundary layer flow over rigid surfaces.

Research limitations/implications

The multiplicity of the compliant wall parameters makes a full parametric study that should show the effect of varying the compliance of the boundary surface on the stability of the flow mathematically intractable. In this study only a brief parametric study, for selected parameters is presented.

Originality/value

It is believed that this paper would be of immense value to applied mathematicians and engineers working in the areas of boundary layer stability and natural convection flows. In the last four decades there has been overwhelming interest shown by researchers in convective boundary‐layer flow. This has largely stemmed from the numerous applications of such flows in geophysics and engineering problems. Many of these applications, for example, polymer and food processing involve the flow of a fluid over a flexible surface. This research aims to bring the dynamics of the surface as a possible mechanism to stabilize convective boundary layer flows and prevent separation.
A local radial point interpolation method for dissipation process of excess pore water pressure
Authors: Wang J.G. , Yan L. , Liu G.R.
Published: August 2005

Purpose

Develop a local radial point interpolation method (LRPIM) to analyze the dissipation process of excess pore water pressure in porous media and verify its numerical capability.

Design/methodology/approach

Terzaghi's consolidation theory is used to describe the dissipation process. A local residual form is formulated over only a sub‐domain. This form is spatially discretized by radial point interpolation method (RPIM) with basis of multiquadrics (MQ) and thin‐plate spline (TPS), and temporally discretized by finite difference method. One‐dimensional (1D) and two‐dimensional consolidation problems are numerically analyzed.

Findings

The LRPIM is suitable, efficient and accurate to simulate this dissipation process. The shape parameters, q=1.03, R=0.1 for MQ and η=4.001 for TPS, are still valid.

Research limitations/implications

The asymmetric system matrix in LRPIM spends more resources in storage and CPU time.

Practical implications

Local residual form requires no background mesh, thus being a truly meshless method. This provides a fast and practical algorithm for engineering computation.

Originality/value

This paper provides a simple, accurate and fast numerical algorithm for the dissipation process of excess pore water pressure, largely simplifies data preparation, shows that the shape parameters from solid mechanics are also suitable for the dissipation process.
Gendered management in Hungary: perceptions and explanations
Authors: Nagy Beáta
Published: August 2005

Purpose

To display both the statistical data and the subjective evaluation on the situation of women in management in Hungary.

Design/methodology/approach

In the last ten years research activity on gender and work countries have concentrated on the investigation of the sociological issue of the extent to which equal opportunity programmes at the company level have been accomplished in Hungary. The investigations consist of two interrelated parts: questionnaires on women's situation in top management completed by HR departments, and in‐depth interviews with employees. This paper brings together these studies and reports on women's management position at senior levels in Hungarian organisations.

Findings

The results show that, although women's share in the elite pool of economic life increased, women are badly represented in higher managerial positions. Neither employers nor employees find this situation problematic, and continuously emphasised the liberal meaning of equality. There were various ideas about the explanation for the poor representation of women in the company boards, but none of them stressed the organisation as the hindrance of women's advancement.

Research limitations/implications

It is not based on a representative sample.

Originality/value

There have been minimal investigations on gender issues at companies in Hungary. These results display not only companies' official opinion but also the employees' perceptions on gender inequality. The paper contributes to the neglected area of gender and management research with the Hungarian and Eastern European context.
Fibre brand promotion and consumer product awareness: case study of Tactel
Authors: Twine C. , Ruckman J.E.
Published: August 2005

Purpose

This case study investigates the consumer perception of Tactel that has resulted from Invista's marketing strategy of generating brand recognition for Tactel and considers whether the consumer understanding of the product and its benefits correlate to the intentions of Invista.

Design/methodology/approach

Interviews, questionnaire and consumer garment comparisons test.

Findings

It was found from interviews conducted with representatives of companies involved in a UK based supply chain producing Tactel lingerie during both the Autumn/Winter (A/W) 2000‐2001 and A/W 2003‐2004 seasons that all representatives agreed that consumers do not understand the meaning of Tactel and do not really understand its benefits. The results from the consumer questionnaire confirm this view as consumers were not able to identify key words associated with Tactel effectively. It was found from the consumer garment comparisons test, however, that although consumers may not be sure about the particular attributes of Tactel and its benefits awareness of the brand has increased following a very focused brand promotion since A/W 2000‐2001. Whilst Tactel may not mean anything to consumers, it is now becoming an integral part of consumers' vocabulary in the A/W 2003‐2004 season as Invista had intended.

Originality/value

A useful insight into consumer recognition of a fibre brand.
A “square‐root rule” for reinsurance? Evidence from several national markets
Authors: Venezian Emilio C. , Viswanathan Krupa S. , Jucá Iana B.
Published: August 2005

Purpose

Using a game‐theoretic model of insurance markets, Powers and Shubik in 2001 derived a mathematical expression for the optimal number of reinsurers for a given number of primary insurers. Subsequently in 2005, Powers and Shubik showed analytically that, for large numbers of primary insurers, this expression is effectively a “square‐root rule”, i.e. the optimal number of reinsurers in a market is given asymptotically by the square root of the total number of primary insurers. In this paper, we test the accuracy of the square‐root rule empirically.

Design/methodology/approach

The numbers of primary insurers and reinsurers existing in a range of 18‐20 different national insurance markets over a period of 11 years are used.

Findings

The empirical results are consistent with the square‐root rule. In addition, we find that the number of reinsurers may also be associated with the market's willingness to pay for risk. When the market's perception of risk is high, there is a greater supply of reinsurance to provide capacity to primary insurers.

Originality/value

An empirical model is presented that deals explicitly with the number of insurers and reinsurers in a market. This is of value to government policymakers and insurance regulators.
Beliefs in Conspiracy Theories Among African Americans: A Comparison of Elites and Masses*
Authors: Simmons William Paul , Parsons Sharon
Published: August 2005

Objective. Several studies have reported a widespread belief in conspiracy theories among African Americans. Such theories have been shown to have possible deleterious effects, especially when they deal with HIV/AIDS. It has been conjectured that African‐American elites could play a role in dispelling these beliefs, unless, of course, they believe in these theories themselves. To examine this possibility the present study examines the conspiratorial beliefs of African‐American locally elected officials in Louisiana and compares them with a previous study of African‐American churchgoers in the same state.

Methods. A systematic sample of 400 African‐American locally elected officials was drawn from a list of all African‐American elected officials in the state and 170 officials completed and returned the mail survey. Confirmatory factor analysis and OLS regression were used to analyze the attitude structure and determinants of beliefs, respectively.

Results. The locally elected officials believe in these theories as much as the churchgoers and the structures of their beliefs are also very similar. In some very important ways, however, the predictors of these beliefs differ between the two samples.

Conclusions. Our findings suggest that beliefs in conspiracy theories are widespread and that African‐American locally elected officials will not seek to dispel these beliefs.
Immunoadsorption patients with multiple sclerosis: an open‐label pilot study
Authors: Moldenhauer A. , Haas J. , Wäscher C. , Derfuss T. , Hoffmann K.‐T. , Kiesewetter H. , Salama A.
Published: August 2005

Background  Immunoadsorption (IA) is occasionally applied in patients with acute relapses of multiple sclerosis (MS). This pilot study was undertaken to determine whether IA might help in secondary progressive and relapsing‐remitting multiple sclerosis.

Design  IA was performed at 1‐week intervals in 12 patients with secondary progressive or relapsing‐remitting MS. These patients had an extended disability status scale (EDSS) score of 4·5–7 and an EDSS increase of 0·5 within 6 months before inclusion in the study despite conventional drug therapy. The change in the EDSS and that in the MS functional composite (MSFC) score, which consisted of quantitative tests of arm function, ambulation, visual acuity and cognition, served as the primary outcome variables, which were measured at baseline and at 3, 6 and 12 months. Changes in quality of life and cerebral lesions by magnetic resonance imaging (MRI) were also assessed at baseline and after the last immunoadsorption (month 3).

Results  A significant reduction of the median EDSS change was observed after the treatment period, which reversed 3 months after the immunoadsorptions had been stopped. Ten of 12 patients remained stable during the first year of follow‐up with no significant changes of the MSFC scores. No significant changes in magnetic resonance imaging T2‐hyperintense brain lesions or in the number of gadolinium‐positive lesions and in the patients’ quality of life were observed. Western blot analyses demonstrated a reduction of serum myelin‐specific antibodies, which were collected in the adsorber eluates.

Conclusions  Removal of immunoglobulins, including myelin‐specific antibodies by immunoadsorption, seems to delay disease progression as defined by EDSS, MSFC and MRI, while the patients’ quality of life did not deteriorate.
Gallbladder Na+/H+ exchange activity is up‐regulated prior to cholesterol crystal formation
Authors: Narins S. C. , Ramakrishnan R. , Park E. H. , Smith P. R. , Meyers W. C. , Abedin M. Z.
Published: August 2005

Background  Gallbladder Na+ and H2O absorption are increased prior to gallstone formation and may promote cholesterol nucleation. Na+/H+ exchange (NHE) isoforms NHE2 and NHE3 are involved in gallbladder Na+ transport in prairie dogs. We examined whether increased gallbladder Na+ absorption observed during early gallstone formation is the result of NHE up‐regulation.

Materials and methods  Native gallbladder and primary cultures of gallbladder epithelial cells (GBECs) harvested from prairie dogs fed nonlithogenic (CON) or 1·2% cholesterol diet for varying lengths of time to induce cholesterol‐saturated bile (PreCRYS), cholesterol crystals (CRYS), or gallstones (GS) were used. NHE activity was assessed by measuring dimethylamiloride‐inhibitable 22Na+ uptake under H+ gradient in primary GBECs. HOE‐694 was used to determine NHE2 and NHE3 contributions. NHE protein and mRNA expression were examined by Western and Northern blots, respectively.

Results  Gallbladder total NHE activity was 25·1 ± 1·3 nmol mg protein−1 min−1 in the control and increased during gallstone formation peaking at the PreCRYS stage (98·4 ± 3·9 nmol mg protein−1 min−1). There was a shift in NHE activity from NHE2 to NHE3 as the animals progressed from no stones through the PreCRYS and CRYS stages to gallstones. The increase in NHE activity was partly caused by an increased Vmax without any change in KNam. Both NHE2 and NHE3 protein increased moderately during the PreCRYS stage without increases in mRNA expression.

Conclusions  Increased gallbladder Na+ absorption observed prior to crystal formation is in part caused by an increase NHE activity which is not fully accounted for by an increase in NHE proteins and mRNA levels but may be explained by enhanced localization in the membranes and/or altered regulation of NHE.