bluuebunny/crossref_metadata_2025 huggingface dataset:
Diamond-like carbon nanocomposite films
Authors: Chen Liang-Yih , Chau-Nan Hong Franklin
Published: May 2003

Diamond-like carbon (DLC) nanocomposite films were deposited at room temperature by inductively coupled plasma chemical vapor deposition using hexamethyldisilane (HMDS), hexamethyldisilazane (HMDSN), and hexamethyldisiloxane (HMDSO) precursors. High-resolution transmission electron microscopy showed that all the films contained nanoparticles. The DLC nanocomposite films deposited by HMDS contained hollow spherical nanocrystallites, called nanoballs, of hexagonal silicon carbide. The nanocomposite films deposited by HMDSN contained crystalline Si3N4 nanoparticles. The nanocomposite films deposited by HMDSO contained amorphous SiOx nanoparticles. Although both types of films had similar hardness, the DLC nanocomposite films exhibited much lower compressive stresses than the DLC films deposited by methane, i.e., 1.5 vs 11 GPa, respectively. Through the enhancement of gas phase reactions, the inductively coupled plasma should be responsible for the formation of nanoparticles in the nanocomposite films.
Atomic-layer doping in Si by alternately supplied NH3 and SiH4
Authors: Jeong Youngcheon , Sakuraba Masao , Murota Junichi
Published: May 2003

Low-temperature Si growth on the atomic-layer order nitrided Si(100) surface with N amount of 1–6×1014 cm−2 formed by NH3 reaction at 400 °C were investigated using an ultraclean low-pressure chemical vapor deposition system. The epitaxial growth of Si film on the nitrided Si(100) with the initial N amount as high as about 3×1014 cm−2 is realized at 500 °C, although the film becomes amorphous in the case at the initial surface N amount of 6×1014 cm−2. By the analysis of the x-ray photoelectron spectroscopy, it is observed that the surface structure of the atomic-layer order nitrided Si(100) is changed into Si3N4 structure by the increase of the surface N amount. It is suggested that the crystallinity of Si film deposited on the atomic-layer order nitrided Si(100) is degraded by the existence of Si3N4 structure. Depth profile of N atomic-layer doped Si film clearly shows that most of the N atoms are confined within about 1-nm-thick region.
Optical properties of the isoelectronic trap Hg in ZnO
Authors: Agne Th. , Dietrich M. , Hamann J. , Lany S. , Wolf H. , Wichert Th. ,   ISOLDE Collaboration
Published: May 2003

Nominally undoped ZnO crystals were doped with Hg by implanting radioactive Hg197/197Au atoms. After annealing at 1073 K, the photoluminescence (PL) spectra recorded at 1.6 K exhibit a Hg related band in the region between 3.28 and 2.85 eV. The sharp no-phonon line, which is observed at 3.276 51 eV, is assigned to a bound exciton. At lower energies, a phonon sideband is visible, which is caused by the strong coupling with acoustical and optical phonons. It is shown that these PL signals are caused by an exciton bound to a Hg atom that resides on a cation site.
Integrated piezoresistive sensors for atomic force-guided scanning Hall probe microscopy
Authors: Brook A. J. , Bending S. J. , Pinto J. , Oral A. , Ritchie D. , Beere H. , Henini M. , Springthorpe A.
Published: May 2003

We report the development of an advanced sensor for atomic force-guided scanning Hall probe microscopy whereby both a high mobility heterostructure Hall effect magnetic sensor and an n-Al0.4Ga0.6As piezoresistive displacement sensor have been integrated in a single III–V semiconductor cantilever. This allows simple operation in high-vacuum/variable-temperature environments and enables very high magnetic and topographic resolution to be achieved simultaneously. Scans of magnetic induction and topography of a number of samples are presented to illustrate the sensor performance at 300 and 77 K.
Microcantilever resonance-based DNA detection with nanoparticle probes
Authors: Su Ming , Li Shuyou , Dravid Vinayak P.
Published: May 2003

Microcantilevers are used to detect DNA strands with a specific sequence using gold nanoparticle modified DNA. The hybridization reactions lead to the attachment of gold nanoparticles. After the amplification process by catalyzing the nucleation of silver, the shift of the cantilever frequency signals the binding events. The method can detect target DNA at a concentration of 0.05 nM or lower. Combined with stringency washing, a single base pair mismatched DNA strand can be discriminated. The cantilever is 1/100 times smaller than its macroscopic counterpart (quartz crystal microbalance), and can be mass produced as miniaturized sensor arrays by current processing technology. Multiple DNA detection is possible by coating multiple cantilevers with various capture DNA strands and monitoring the change in their resonance frequencies.
Kelvin probe force microscopy study of SrBi2Ta2O9 and PbZr0.53Ti0.47O3 thin films for high-density nonvolatile storage devices
Authors: Son J. Y. , Bang S. H. , Cho J. H.
Published: May 2003

Polycrystalline ferroelectric thin films of SrBi2Ta2O9 (SBT) and PbZr0.53Ti0.47O3 (PZT) were deposited on Pt/Ti/SiO2/Si substrate by pulsed laser deposition using an eclipse method and the surface potentials were observed by Kelvin probe force microscopy. The data suggest that the surface charge trap is a dominant effect over the ferroelectric polarization when a high electric field is applied on a cantilever during writing. This results from the increase of surface trapped charge and the saturation of ferroelectric remanent polarization. The data also indicate that the SBT thin films can easily trap surface charges than that of the PZT thin films. By properly biasing low voltage, the magnitude and the sign of surface potential are determined by the ferroelectric polarization than by the trapped surface charges.
An accumulative x-ray streak camera with sub-600-fs temporal resolution and 50-fs timing jitter
Authors: Liu Jinyuan , Wang Jin , Shan Bing , Wang Chun , Chang Zenghu
Published: May 2003

We demonstrated that the shot-to-shot timing jitter of an x-ray streak camera was reduced to close to 50 fs when it was triggered by a standard kilohertz laser with 1.2% rms pulse energy fluctuation. This was achieved by improving the response time of deflection plates and the rise time of the ramp pulse generated by a photoconductive switch, and by operating the photoconductive switch at optimum conditions. Furthermore, after reducing the angular distribution of electron bunch, the temporal resolution of the x-ray streak camera operating in accumulation mode was measured to be better than 600 fs.
Damping of micromechanical structures by paramagnetic relaxation
Authors: Harris J. G. E. , Knobel R. , Maranowski K. D. , Gossard A. C. , Samarth N. , Awschalom D. D.
Published: May 2003

We find that the damping of micromechanical cantilevers is sensitive to the relaxation dynamics of paramagnetic ions contained within the levers. We measure cantilevers containing paramagnetic Mn ions as a function of temperature, magnetic field, and the vibrational mode of the lever and find that the levers’ damping is strongly enhanced by the interplay between the motion of the lever, the ions’ magnetic anisotropy, and the ratio of the ions’ longitudinal relaxation rate to the resonance frequency of the cantilever. This enhancement can improve the levers’ ability to probe the relaxation behavior of paramagnetic or superparamagnetic systems; it may also represent a previously unrecognized source of “intrinsic” dissipation in micromechanical structures.
Continuous formation and faceting of SiGe islands on Si(100)
Authors: Sutter P. , Zahl P. , Sutter E.
Published: May 2003

The multiscale mechanisms leading to the formation of faceted quantum dot (QD) islands during Si1−xGex/Si(100) heteroepitaxy were studied by scanning tunneling microscopy. The entire evolution from an initial morphological instability of the strained alloy to final {105} faceted pyramidal QD islands is continuous. Shallow mounds, generated by the alloy instability, are bounded by alternating (100) terraces and single-layer steps. Growth of the mounds in height without lateral expansion drives a continuous increase in mound slope and step density up to a critical angle of about 6°. Kinetic constraints then force the nucleation of small {105} protofacets, which expand and ultimately coalesce to form the {105} facets bounding pyramidal QD islands.
Easy method to adjust the angle of the carbon nanotube probe of an atomic force microscope
Authors: Chang Y. C. , Wang D. C. , Chang C. S. , Tsong Tien T.
Published: May 2003

A simple, practical, and reliable method has been developed to bend the carbon nanotube probe of an atomic force microscope to vertically align with the sample structure. It must first be realized that carbon nanotubes can be plastically deformed only when they are in bundle. The bundled tubes can be bent gradually and almost continuously. By scanning a patterned sample, both the bent position and angle of the attached tube probe can be adjusted. These probes also display a self-tuning character, which makes them superior than other supersharp tips for imaging structures of great depth.
Far-infrared-magneto-optic ellipsometry characterization of free-charge-carrier properties in highly disordered n-type Al0.19Ga0.33In0.48P
Authors: Hofmann T. , Schubert M. , Herzinger C. M. , Pietzonka I.
Published: May 2003

For highly disordered n-type Al0.19Ga0.33In0.48P grown lattice matched to an undoped GaAs substrate, using far-infrared-magneto-optic generalized ellipsometry, the room-temperature free-charge-carrier parameters effective mass m*=0.12(0.01) m0, concentration N=6.7(0.2)×1017 cm−3, and mobility μ=339(15) cm2/(V s) are determined by modeling the observed magneto-optic birefringence originating from the far-infrared free-charge-carrier excitations in the Al0.19Ga0.33In0.48P layer without additional electrical measurements.
Contributions from gallium vacancies and carbon-related defects to the “yellow luminescence” in GaN
Authors: Armitage R. , Hong William , Yang Qing , Feick H. , Gebauer J. , Weber E. R. , Hautakangas S. , Saarinen K.
Published: May 2003

Carbon-doped GaN layers grown by molecular-beam epitaxy are studied with photoluminescence and positron annihilation spectroscopy. Semi-insulating layers doped with >1018 cm−3 carbon show a strong luminescence band centered at ∼2.2 eV (yellow luminescence). The absolute intensity of the 2.2 eV band is compared with the gallium vacancy concentration determined by positron annihilation spectroscopy. The results indicate that a high concentration of gallium vacancies is not necessary for yellow luminescence and that there is in fact a causal relationship between carbon and the 2.2 eV band. Markedly different deep-level ionization energies are found for the high-temperature quenching of the 2.2 eV photoluminescence in carbon-doped and reference samples. We propose that while the model of Neugebauer and Van de Walle [Appl. Phys. Lett. 69, 503 (1996)] applies for GaN of low carbon concentration, a different yellow luminescence mechanism is involved when the interstitial carbon concentration is comparable to or exceeds the gallium vacancy concentration.
Laser ablation of Co:ZnO films deposited from Zn and Co metal targets on (0001) Al2O3 substrates
Authors: Prellier W. , Fouchet A. , Mercey B. , Simon Ch. , Raveau B.
Published: May 2003

We report on the synthesis of high-quality Co-doped ZnO thin films using the pulsed laser deposition technique on (0001)-Al2O3 substrates performed in an oxidizing atmosphere, using Zn and Co metallic targets. We first optimized the growth of ZnO in order to obtain the less strained film. Highly crystallized Co:ZnO thin films are obtained by an alternative deposition from Zn and Co metal targets. This procedure allows an homogenous repartition of the Co in the ZnO wurzite structure which is confirmed by the linear dependence of the out-of-plane lattice parameter as a function of the Co dopant. In the case of 5% Co doped, the film exhibits ferromagnetism with a Curie temperature close to the room temperature.
Reduced scaling in electronic structure calculations using Cholesky decompositions
Authors: Koch Henrik , Sánchez de Merás Alfredo , Pedersen Thomas Bondo
Published: May 2003

We demonstrate that substantial computational savings are attainable in electronic structure calculations using a Cholesky decomposition of the two-electron integral matrix. In most cases, the computational effort involved calculating the Cholesky decomposition is less than the construction of one Fock matrix using a direct O(N2) procedure.
Biosynthesis of chondroitinase and hyaluronidase by different strains of Paracoccidioides brasiliensis
Authors: de Assis C.  M. , Gandra R.  F. , Gambale W. , Shimizu M.  T. , Paula C.  R.
Published: May 2003

The biosynthesis of chondroitinase and hyaluronidase by different isolates of Paracoccidioides brasiliensis was investigated in 20 strains isolated from patients (17 strains), a penguin (Pygocelis adeliae, one strain), an armadillo (Dasypus novemcinctus, one strain) and the environment (dog food, one strain). All the P. brasiliensis isolates studied had the ability to produce chondroitinase and hyaluronidase, although differences in colony morphology and enzyme production were detected among them. These results suggest that further investigations should be carried out in the clinical field in order to clarify the potential role of P. brasiliensis enzyme production in the pathogenesis of paracoccidioidomycosis.
Genotypic and phenotypic characterization of attaching and effacing Escherichia coli (AEEC) isolated from children with and without diarrhoea in Londrina, Brazil
Authors: Nunes Eliane Blanco , Saridakis Halha Ostrensky , Irino Kinue , Pelayo Jacinta Sanchez
Published: May 2003

Attaching and effacing Escherichia coli (AEEC) have been implicated in diarrhoea in humans in several countries. A total of 919 E. coli strains, isolated from 125 children with diarrhoea and 98 without diarrhoea, was investigated by PCR for the presence of the EAF, bfp, eae and stx genes. Thirty-four of these isolates were found to carry the eae gene; they were isolated from 27 (79.4 %) children with diarrhoea and seven (20.6 %) controls, in the city of Londrina, Brazil. These strains were investigated for their genotypic and phenotypic characteristics. Different genetic profiles were observed; strains containing the eae gene alone were most common (47.1 %). The characteristic genetic profile of typical enteropathogenic E. coli (EPEC), eae, bfp and EAF, was only found in isolates from children with diarrhoea. The stx gene was not detected in any of the 34 strains studied. Ten (29.4 %) strains were negative in the fluorescent actin-staining test. Localized adhesion (LA) was the most common pattern of adhesion (44.1 %), followed by the aggregative adhesion (AA) (23.5 %) and localized adhesion-like (LAL) (14.7 %) patterns. The results showed a strong association between strains presenting the LA pattern and diarrhoea. Forty-seven per cent of the strains studied belonged to classical O-serogroups of EPEC. The most common serotype found was O119 : H6; these isolates all showed the LA pattern, were positive for fluorescent actin-staining and were associated with diarrhoea. Intimin β was detected in seven strains, four of which belonged to serotype O119 : H6 and three to serotype ONT : H7; all were associated with diarrhoea. On the other hand, intimin ϵ was detected in two strains of serotype O111 : H38 and one of serotype ONT : H19, isolated from children without diarrhoea. To our knowledge, this is the first report of the occurrence of intimin ϵ in strains of E. coli isolated from humans in Brazil.
Tracing clonality of Helicobacter pylori infecting family members from analysis of DNA sequences of three housekeeping genes (ureI, atpA and ahpC), deduced amino acid sequences, and pathogenicity-associated markers (cagA and vacA)
Authors: Owen, Robert J. , Xerry Jacqueline
Published: May 2003

Helicobacter pylori, a Gram-negative bacterium, is a causal agent of peptic ulcers and is estimated to infect the gastric mucosa of at least half of the world's population. As primary infections are acquired mainly by household contact, studies on family clusters provide a model for investigating transmission and the natural history of initial infection. Here, sequence typing exploiting genetic variation in core fragments of three key housekeeping loci (ureI, atpA and ahpC) was used to determine clonal descent amongst isolates of ten members of four families in Northern Ireland and a family with three generations in central England. Phylogenetic analysis of each locus for 73 strains of H. pylori from 11 countries indicated high background intraspecific diversity, apart from identical paired isolates from five unrelated patients and strains with identical sequence types (STs) detected in adult members of two families. In several families carrying strains with different STs, evidence of residual clonal descent was detected at one or two loci by comparison of nucleotide and amino acid sequences. Pathogenicity-associated genotypes were heterogeneous with respect to ST and amino acid type. Analysis of these three housekeeping genes provides unique evidence for precise tracing of clonal descent in isolates of H. pylori in family groups.
Incidence of virulence determinants in clinical Enterococcus faecium and Enterococcus faecalis isolates collected in Sardinia (Italy)
Authors: Duprè I. , Zanetti S. , Schito A.  M. , Fadda G. , Sechi L.  A.
Published: May 2003

Enterococci are widely distributed in the environment; within the human body, they are normal commensals of the oral cavity, gastrointestinal tract and vagina. In recent years, enterococci have become one of the most frequent causes of acquired nosocomial infections worldwide. The molecular mechanism of virulence of these bacteria is still not completely understood. The aims of this work were to characterize phenotypically 47 isolates of Enterococcus faecalis and Enterococcus faecium collected in Sardinia (Italy) by their abilities to adhere to different epithelial cell lines (Vero and Caco-2 cells) and to associate their phenotypes with the presence of known virulence genes detected within their genomes by PCR. The following genes were amplified: AS (aggregation substance), esp (surface protein gene), ace (accessory colonization factor), efaA (E. faecalis endocarditis antigen) and gelE (gelatinase). The virulence genes were detected in E. faecalis isolates only, with the exception of esp, which was found in both species. The phenotypic and genotypic results were also compared with the susceptibility of isolates to various antibiotics.
NapA protects Helicobacter pylori from oxidative stress damage, and its production is influenced by the ferric uptake regulator
Authors: Cooksley Clare , Jenks Peter J. , Green Andrew , Cockayne Alan , Logan Robert P.  H. , Hardie Kim R.
Published: May 2003

The Helicobacter pylori protein NapA has been identified as a homologue of the Escherichia coli protein Dps. It is shown in this study that, like Dps, NapA is produced maximally in stationary phase cells and contributes to the ability of H. pylori to survive under oxidative stress conditions. Moreover, NapA co-localizes with the nuclear material, suggesting that it can interact with DNA in vivo. Furthermore, it is demonstrated that repression of NapA production by iron starvation was not so pronounced in a H. pylori fur mutant, suggesting that the ferric uptake regulator (Fur) is involved in napA regulation, and a potential fur box by which this control could be mediated is identified. This finding is consistent with the regulation of iron-binding proteins by Fur and also the modulation of Fur during oxidative stress, thus allowing NapA levels to be increased in the environmental conditions under which its ability to protect DNA from attack by toxic free radicals is most beneficial to the cell.
Molecular comparison of bacterial isolates from blood with strains colonizing pharynx and intestine in immunocompromised patients with sepsis
Authors: Murono Koichi , Hirano Yoshiki , Koyano Shin , Ito Kiminari , Fujieda Kenji
Published: May 2003

Most causative organisms of sepsis in immunocompromised patients are the same species as those that colonize their own nasopharynx or intestinal tract. To determine whether the strains recovered from blood originate mainly from patients’ own flora, isolates from blood and throat and/or stool were investigated by genomic analyses. Surveillance cultures of throat and stool were taken prospectively from cancer patients being treated with intensive chemotherapy followed by haematopoietic stem-cell transplantation. In those cases of sepsis in which the isolate from blood was the same species as that from the throat and/or stool, the genomic profiles of the isolates were compared by PFGE. Ten cases of blood culture-positive sepsis were documented in six of 14 subjects during a 2 year period; isolates of Pseudomonas aeruginosa, Staphylococcus epidermidis, Enterococcus sp., viridans streptococci and Fusobacterium sp. were recovered from blood. In five of seven cases in which the blood isolate was the same species as that from the throat or stool, the genotypes of the isolates from both sites were identical. In the majority of immunocompromised patients, the causative organisms of bloodstream infections originated mainly from their own flora.
Lysogeny and bacteriophage host range within the Burkholderia cepacia complex
Authors: Langley Ross , Kenna Dervla T. , Vandamme Peter , Ure Rebecca , Govan John R.  W.
Published: May 2003

The Burkholderia cepacia complex comprises a group of nine closely related species that have emerged as life-threatening pulmonary pathogens in immunocompromised patients, particularly individuals with cystic fibrosis or chronic granulomatous disease. Attempts to explain the genomic plasticity, adaptability and virulence of the complex have paid little attention to bacteriophages, particularly the potential contribution of lysogenic conversion and transduction. In this study, lysogeny was observed in 10 of 20 representative strains of the B. cepacia complex. Three temperate phages and five lytic phages isolated from soils, river sediments or the plant rhizosphere were chosen for further study. Six phages exhibited T-even morphology and two were lambda-like. The host range of individual phages, when tested against 66 strains of the B. cepacia complex and a representative panel of other pseudomonads, was not species-specific within the B. cepacia complex and, in some phages, included Burkholderia gladioli and Pseudomonas aeruginosa. These new data indicate a potential role for phages of the B. cepacia complex in the evolution of these soil bacteria as pathogens of plants, humans and animals, and as novel therapeutic agents.
Five postulates for resolving outbreaks of infectious disease
Authors: Mortimer Philip P.
Published: May 2003

Outbreaks of infection challenge the surveillance of infectious disease, but they also offer opportunities to improve and refine it. An outbreak may be the first sign of an emerging pathogen or it may draw attention to a new risk group or route of infection. Postulates analogous to those used a century ago by Robert Koch to prove the microbial aetiology of infectious diseases can be employed to verify the existence of an outbreak, demonstrate its cause and pinpoint its origins. In doing this, high-resolution molecular finger printing of micro-organisms has now assumed a crucial role. Without formal analysis based on postulates, the existence, extent and source of outbreaks may be overlooked and public health interventions misapplied or lost.
Role of elastase in a mouse model of chronic respiratory Pseudomonas aeruginosa infection that mimics diffuse panbronchiolitis
Authors: Yanagihara Katsunori , Tomono Kazunori , Kaneko Yukihiro , Miyazaki Yoshitsugu , Tsukamoto Kazuhiro , Hirakata Yoichi , Mukae Hiroshi , Kadota Jun-ichi , Murata Ikuo , Kohno Shigeru
Published: May 2003

Pseudomonas aeruginosafrequently colonizes the respiratory tract of patients suffering from cystic fibrosis (CF) and diffuse panbronchiolitis (DPB). However, the relationship between lung inflammation and extracellular products ofP. aeruginosais not well-defined. To assess the role of elastase released byP. aeruginosain DPB, a murine model of DPB was employed in this study. Mice were inoculated with eitherP. aeruginosaPAO1 or PAO-E64; the latter produces elastase with greatly reduced enzymic activity. Throughout the 90-day experiments, counts of viable bacteria from the PAO1- and PAO-E64-infected mice were found to be equivalent. However, the number of lymphocytes isolated from the lungs of PAO-E64-infected mice was significantly lower than the number isolated from the lungs of PAO1-infected animals. Histopathological examination of the lungs of mice infected by PAO1 on day 90 revealed an intense accumulation of chronic respiratory cells surrounding the bronchi, in sharp contrast to the more localized inflammatory response found in those mice infected by PAO-E64. These data suggest thatP. aeruginosaelastase (PE) is a potent inflammatory factor in a mouse model of DPB and that the control of PE release byP. aeruginosamay be beneficial for patients with DPB.
Increasing incidence of group A streptococcal infections amongst injecting drug users in England and Wales
Authors: Efstratiou Androulla , Emery Michaela , Lamagni Theresa L. , Tanna Asha , Warner Marina , George Robert C.
Published: May 2003

During 2000, the UK witnessed a sudden increase in severe infections and related deaths in injecting drug users (IDUs), sparking off a UK-wide investigation. A worrying upward trend in severe group A streptococcal (GAS) infections has recently been observed in IDUs based upon isolate referrals to the PHLS Respiratory and Systemic Infection Laboratory. Most cases were young male adults who presented with skin sepsis and bacteraemia. Serotyping revealed a diverse range of M types, with higher types predominating in some geographical areas. The data suggest that GAS invasive soft-tissue infections may present in an epidemic fashion among IDUs in the absence of a common source.
Development of acquired immunity to Salmonella
Authors: Mastroeni, Pietro , Ménager Nathalie
Published: May 2003

Salmonella entericaserovar Typhi (S. typhi) causes human typhoid fever, a serious and widespread disease in developing countries. OtherSalmonellaserovars are associated with food-borne infections. The recent emergence of multi-drug-resistantSalmonellastrains highlights the need for better preventive measures, including vaccination. The available vaccines againstSalmonellainfection do not confer optimal protection. The design of newSalmonellavaccines must be based on the identification of suitable virulence genes and on knowledge of the immunological mechanisms of resistance to the disease. Control and clearance of a vaccine strain rely on the phagocyte oxidative burst, reactive nitrogen intermediates, inflammatory cytokines and CD4+TCR-αβ+T cells and are controlled by genes includingNRAMP1and MHC class II. Vaccine-induced resistance to reinfection requires the presence of Th1-type immunological memory and anti-Salmonellaantibodies. The interaction between T and B cells is essential for the development of resistance following vaccination. The identification of immunodeficiencies that render individuals more susceptible to salmonellosis must be taken into consideration when designing and testing live attenuatedSalmonellavaccines. An ideal liveSalmonellavaccine should therefore be safe, regardless of the immunological status of the vaccinee, but still immunogenic.
Financial service firms’ entry‐mode choice and cultural diversity: Spanish companies in Latin America
Authors: José Álavarez‐Gil María , Cardone‐Riportella Clara , Lado‐Cousté Nora , Samartín‐Sáenz Margarita
Published: May 2003

Emerging markets in newly industrialised countries have caught the attention of managers of manufacturing companies facing heavy domestic and global pressure. Key barriers to the effective management of international manufacturing operations need to be identified. The same applies to the management of international service operations. The share of services in international trade, the amount of foreign direct investments made and the number of multinational service‐sector enterprises has been increasing rapidly in the last two decades. Existing studies on service internationalisation apply a fairly broad theoretical base. This paper contributes by examining the internationalisation behaviour of Spanish financial service‐sector companies in Latin America to find out if general internationalisation patterns are applicable or if the manufacturing sector influences their internationalisation behaviour.
Voices from the Top of the Pile: Elite Perceptions of Poverty and the Poor in the Philippines
Authors: Clarke Gerard , Sison Marites
Published: May 2003

How do elites perceive poverty and the poor? In this article, we present the results of interviews with eighty members of the Filipino elite, undertaken as part of a larger six‐country study of elite perceptions of poverty and the poor. Poverty, we argue, is a highly subjective phenomenon. People's perceptions of poverty, of who is and who is not poor, of how poverty affects them and others, and of how poverty can be effectively tackled, vary enormously between different types of people (defined in terms of class, status, occupation, nationality, ethnicity, gender or a myriad of other social identities). Wherever people cohere as groups, classes or other social constructs, perceptions of poverty are aggregated and refined and then embedded in social dynamics. The study of elite perceptions of poverty and the poor, we conclude, can both add to our understanding of the social dynamics of poverty and inequality and inform pro‐poor public policy.
Whose Modernity? Indigenous Modernities and Land Claims after Apartheid
Authors: Robins Steven
Published: May 2003

This article questions some of the key assumptions of post‐development and anti‐development critics such as Arturo Escobar and Wolfgang Sachs, who tend to prescribe a puritanical and principled rejection of ‘exogenous development’ that does not necessarily reflect the needs and desires of the beneficiaries of development. Drawing on fieldwork research on land claims in Northern Cape and Northern Provinces (South Africa), the author argues that these beneficiaries tend to deploy hybrid and highly selective and situational responses to development interventions. These hybrid responses can be regarded as indigenous modernities. Development packages are resisted, embraced, reshaped or accommodated depending on the specific content and context. The author also questions James Ferguson's conclusion that depoliticizing development discourses inevitably buttresses bureaucratic state power. Rather, the fieldwork findings suggest that state‐led development is often an extremely risky business that can undermine the legitimacy and authority of governments. In addition, in many parts of the developing world, it is the retreat of the neo‐liberal state, rather than ‘the tyranny of development’, that poses the most serious threat to household livelihood strategies and economic survival. The case studies discussed here suggest that responses to development are usually neither wholesale endorsements nor radical rejections of modernity. Even when resisting and subverting development ideas and practices, people do not generally do so on the basis of either radical populist politics or in defence of pristine and authentic local cultural traditions.
Examining the Potential of Indigenous Institutions for Development: A Perspective from Borana, Ethiopia
Authors: Watson Elizabeth E.
Published: May 2003

This article examines an institutional approach to development in which indigenous institutions are viewed as a resource for achieving development. It concentrates on indigenous natural resource management (NRM) institutions which have been seen by some development agencies to be a means to address the needs of people and the environment in a way that is also participatory. Using material from Borana, Ethiopia, the article describes the indigenous NRM institutions and examines the outcome of one attempt to work with them. In the process, it shows that partnerships between development agencies and indigenous NRM institutions are often fragile, and tend to dissolve when they fail to meet the preconceptions of the developers. Through an examination of this approach to development, the article also examines the usefulness of recent broad approaches to institutions.
Robustness of Spatial Autocorrelation Specifications: Some Monte Carlo Evidence
Authors: Dubin Robin
Published: May 2003

Abstract This paper examines the robustness of various models of spatial autocorrelation through a series of Monte Carlo experiments in which each model takes a turn at the data generator. The generated data are then used to estimate all of the models. The estimated models are evaluated primarily on their predictive power.
The Role of Cultural Clustering in Attracting New Immigrants
Authors: Gross Dominique M. , Schmitt Nicolas
Published: May 2003

Abstract This paper argues that new immigrants cluster in culturally homogeneous groups in the host country because of imperfect information. However, a pulling effect exists provided that the cultural communities are not too large. With a panel of migration flows to the major O.E.C.D. countries from the mid 1980s to the mid 1990s, it is shown that the existence of similar cultural communities attracts new immigrants. However, the effect is not homogeneous for all types of source and destination countries. Furthermore, the pulling effect is shown to fall to zero for cultural communities above a certain threshold size.
Building Spatial Choice Models from Aggregate Data
Authors: Orpana Tommi , Lampinen Jouko
Published: May 2003

AbstractChoice model construction is usually based on information about a number of separate choice situations, for which all relevant quantities are known. This paper concerns the case where only higher level, aggregate information is available about the choice results and the prevailing conditions. We demonstrate the applicability of a generic inverse parameter estimation method in estimating a model for grocery store choice. We also propose some enhancements to standard spatial choice models and demonstrate their applicability.
The Impact of a Customs Union with the European Union on Internal Migration in Turkey
Authors: De Santis Roberto A.
Published: May 2003

Abstract The impact of the recent Customs Union (CU) agreement between Turkey and the European Union on internal migration is studied using an intra‐industry trade Computable General Equilibrium (CGE) model with intersectoral capital mobility under two alternative specifications for the labor market: the traditional Harris‐Todaro approach and the existence of a “wage curve” in the urban sector. Under both specifications, the numerical results show that the CU is welfare enhancing and causes a reduction of the urban‐rural wage gap as suggested by theoretical studies. At the same time, it leads to rural‐to‐urban migration and raises the capital rent, results that are counter intuitive with respect to the dual economy literature. Furthermore, the rise in formal labor demand and the migration response to the CU have not resulted in an increase in urban unemployment (i.e. the “Todaro paradox”), but rather to a fall in the unemployment pool. The study also shows that the Bhagwati‐Srinivasan proposal of maximizing welfare by uniformly subsidizing the entire labor market is impracticable, especially if the high wage union sector can negotiate employment conditions.
Predicting National and Regional Recessions Using Probit Modeling and Interest‐Rate Spreads
Authors: Shoesmith Gary L.
Published: May 2003

Abstract This study extends the work of Estrella and Mishkin (1996, 1998) to show that interest‐rate spreads and probit modeling can be used to predict recessions in many states as well as the nation. State recessions are defined as two or more consecutive quarters of declining real gross state product. The yield spread, SPREAD, is defined as the difference between the 10‐year Treasury bond rate and the three‐month Treasury bill rate. The national results are similar to those obtained by Estrella and Mishkin. Probit models are estimated for all 50 states using SPREAD and unemployment insurance claims, UI, as alternative explanatory variables. For 34 of the 50 states, SPREAD is significant at the 0.01 level as a predictor of state recessions. Much weaker results are obtained using UI. Simulations for the 1979–2001 period are used to compute loss functions for the national and state models at probability screens of 30, 40, 50, and 60 percent. The results demonstrate that probit models based on SPREAD can be useful in improving business and policy decisions in many states.
Maximum Sustainable Government Debt in the Overlapping Generations Model
Authors: Rankin Neil , Roffia Barbara
Published: May 2003

The theoretical determinants of maximum sustainable government debt are investigated using Diamond's overlapping generations model. A level of debt is defined to be ‘sustainable’ if a steady state with non‐degenerate values of economic variables exists. We show that a maximum sustainable level of debt almost always exists, and it normally occurs where variables such as capital are in the interiors, rather than at the limits, of their economically feasible ranges. This leads to a situation where, when debt is at its maximum, a further infinitesimal increase in debt causes a ‘catastrophe’, i.e. the economy embarks on a path of unchecked capital decumulation.
On Public Investment, the Real Exchange Rate and Growth: Some Empirical Evidence from the UK and the USA
Authors: Ghosh Sugata , Mourmouras Iannis A. , Pal Sarmistha , Paya Ivan
Published: May 2003

This study is based on a two‐country endogenous growth model with optimizing agents, where public investment affects the real exchange rate and the long‐run growth rate, and does so in a non‐linear fashion. Non‐parametric regression analysis of quarterly data from the UK and the USA suggests that there is a significant non‐linear relationship between public investment and the real exchange rate, and also between public investment and the growth rate. This is also supported by our parametric generalized method of moments model that jointly determines the real exchange rate, growth rate and net foreign assets in terms of public investment.
A Tale of Two Cycles: Co‐Fluctuations Between UK Regions and the Euro Zone
Authors: Barrios Salvador , Brülhart Marius , Elliott Robert J.R. , Sensier Marianne
Published: May 2003

We examine the patterns and determinants of business cycle correlations among 11 UK regions and six euro‐zone countries over the 1966–97 period, using the generalized method of moments to allow for sampling error in comparing estimated correlations. The British business cycle is found to be persistently out of phase with that of the main euro‐zone economies, and the trend is towards lower correlations. We detect only minor cyclical heterogeneity among UK regions. Differences in sectoral specialization drive some of the asymmetry in GDP fluctuations, but they do not appear significant in explaining the observed reduction in UK–EU business cycle correlations over time.
Some Econometric Issues in Convergence Regressions
Authors: Liberto Adriana Di , Symons James
Published: May 2003

Despite the abundance of different econometric techniques introduced in the empirical literature on convergence, it is usually assumed that shocks are uncorrelated across countries. This is unlikely for most of the data sets considered and we investigate a possibility so far ignored, namely the annual panel estimator where shocks are allowed to be correlated. Our analysis is restricted to the case of T > N which allows us to estimate by maximum likelihood with an unrestricted variance–covariance matrix of cross‐country shocks. We examine by Monte Carlo robustness against certain possible misspecifications, namely measurement error and heterogeneity of the convergence coefficients.
Wage Centralization and the Scope of Firm–Union Bargaining: ‘Efficient Bargains’ or ‘Labour Demand’?
Authors: Vlassis Minas
Published: May 2003

This paper focuses on the role that wage centralization may play regarding the endogenous determination of the scope of firm–union bargaining. Findings suggest that, as long as the alternative wage is sufficiently low, compliance with the centralized (minimum) wage deal is sustained by wage‐takers (small inefficient employers and their employees), and ‘labour demand’ proves to be an equilibrium bargaining arrangement for wage‐setters (large efficient employers and their workers’ union). Otherwise, and also if union power is low enough, ‘efficient bargains’ may be unanimously chosen by the latter agents, as a strategic device to counter losses arising from wage‐undercutting rivalry.
A Framework for Promoting Mental Health in School
Authors: Hornby Garry , Atkinson Mary
Published: May 2003

Schools have an important role to play in the promotion of children's mental health, as well as in the identification and treatment of children with mental health problems. This article proposes a framework for a whole school approach to mental health. The framework focuses on four levels of involvement. The most general level is concerned with school ethos, which encompasses the values shared by all staff and pupils. The next level is whole‐school organization, which comprises a range of school policies. Then there is pastoral provision, which concerns procedures in place throughout the school. The final level is classroom practice, which involves the practical strategies used by teachers. A model is presented in order to illustrate visually the four levels in the framework for the promotion of mental health in schools. It is intended that the model will provide schools with a useful framework with which to review their provisions for children with mental health problems and consider the issue of mental health promotion.
A Social Skills Training (SST) Programme for Victims of Bullying
Authors: Fox Claire L. , Boulton Michael J.
Published: May 2003

The article begins with an introduction to the problem of bullying in schools. Next, the relative strengths and weaknesses of some interventions for victims of bullying are discussed. In the second part of this article the reader is introduced to the Social Skills Training Programme that the writers developed. In particular, some of the practicalities of setting up and conducting the groups are mentioned. The content of the sessions, in terms of the skills that were focused on and the techniques that were used, are described. In concluding the article some lessons learned for those interested in this type of intervention are offered.
Explaining Location Patterns of Suburban Offices
Authors: Archer Wayne R. , Smith Marc T.
Published: May 2003

Suburban office markets exhibit a pattern of variegated clustering that is little explained by the conventional theories of urban form based on agglomeration effects and the cost of distance. To explain the pattern, this paper introduces industry economies of scale for “Class A” offices. Empirical tests for industry economies of scale are reported, based on data from the office market of Houston, Texas. The models presented, under conditions typical of North American cities in recent decades, imply the patterns of variegated clustering that are observed. They suggest a sequence of clusters, increasing in size and distance from the central business district. Further, they imply the potential for mass movement by tenants from older clusters to new.
Prepayment Behavior of Dutch Mortgagors: An Empirical Analysis
Authors: Charlier Erwin , Van Bussel Arjan
Published: May 2003

The suboptimal exercise of the prepayment option in a mortgage is relevant for mortgage pricing and the management of a mortgage portfolio. Construction of an accurate prepayment model requires quantification of driving factors such as seasoning, seasonality, refinance incentive and burnout. We focus on Dutch mortgages but also discuss the Dutch market in a European setting. Within the euro‐denominated MBS market, the Dutch market is often referred to as the benchmark market. In our application we include typical Dutch market and contract characteristics such as the annual penalty‐free prepayment of 10 to 20% of the original loan amount. We use loan‐level historical data on mortgages originated between January 1989 and June 1999 to estimate separate models for two popular redemption types: savings mortgages and interest‐only mortgages. In both models we allow for suboptimal prepayment behavior. The results clearly indicate that prepayment rates depend on interest rates and the age of the mortgage contract. Moreover, we find that burnout is an important element in describing the prepayment behavior of Dutch mortgagors.
Tax Structure and Natural Vacancy Rates in the Commercial Real Estate Market
Authors: Vandell Kerry D.
Published: May 2003

A number of studies have postulated that the Economic Recovery Tax Act of 1981 (ERTA 1981) was responsible for the dramatic overbuilding that occurred between 1981 and 1986, primarily because returns became less sensitive to “real” demand. While there has been much research on how equilibrium or “natural” vacancy rates in the real estate market are determined, beginning with Rosen and Smith's seminal paper in 1983, virtually none of this work has dealt with the impact of the tax environment. This study makes an initial attempt to answer this question with respect to equilibrium vacancies resulting from tenant (or owner) turnover. A formal model is developed that considers as an objective function the landlord's desire to maximize his/her after‐tax equity returns in an environment of monopolistic competition in which individual projects face downward‐sloping demand curves, owing to market conditions and a degree of heterogeneity among tenants in search costs or some other characteristic. The natural vacancy rate is shown not to depend directly upon the tax environment, but to depend indirectly upon it only to the extent that equilibrium market rents are lowered. The nature of the vacancy response depends critically upon the shape of the tenant demand response relationship upon its transition to a lower‐rent region. This response is interactive with the degree of turnover and supply responsiveness within individual markets.
Controlling for the Impact of Variable Liquidity in Commercial Real Estate Price Indices
Authors: Fisher Jeffrey , Gatzlaff Dean , Geltner David , Haurin Donald
Published: May 2003

Liquidity in private asset markets is notoriously variable over time. Therefore, indices of changes in market value that are based on asset transaction prices will systematically reflect intertemporal differences in the ease of selling a property. We define and develop a concept of “constant‐liquidity value” in the context of a model that is characterized by pro‐cyclical volume of trading. We then present an econometric model that allows for estimation of both a standard transaction‐based price index and a constant‐liquidity index. Our application to the NCREIF database reveals that, in the case of institutional commercial real estate investment, constant‐liquidity values tend to lead transaction‐based and appraisal‐based indices in time, and also to display greater volatility and cycle amplitude. The differences can be significant for strategic investment policy viewed from a mean‐variance portfolio optimization perspective.