bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of electrochemical probes for local void fraction measurement in air-water flows
Authors: Timkin L. S. , Rivière N. , Cartellier A. , Kashinsky O. N.
Published: July 2003

Although electrochemical sensors have been extensively used at the Institute of Thermophysics to diagnose various bubbly flows, their performances in terms of local void fraction measurements have never been checked. This note reports some qualifications of this sensor in air-water flows with bubbles above 2 mm in size. The electrochemical probe associated with an absolute thresholding technique underestimates the void fraction by −3% to −16% (in relative value). In the gas-lift regime, the performance drops to −23%. Although these uncertainties are expected to deteriorate as the bubble size decreases or the liquid viscosity increases, the above magnitudes provide reliable confidence intervals for the exploitation of existing data bases.
Demonstration of a low-noise near-infrared photon counter with multiphoton discrimination
Authors: Miller Aaron J. , Nam Sae Woo , Martinis John M. , Sergienko Alexander V.
Published: July 2003

We have demonstrated a system capable of directly measuring the photon-number state of a single pulse of light using a superconducting transition-edge sensor microcalorimeter. We verify the photon-number distribution of a weak pulsed-laser source at 1550 nm. Such single-photon metrology at telecommunication wavelengths provides the foundation for ensuring the security of photon sources used in implementations of quantum cryptography. Additionally, this system has the lowest noise equivalent power of any single-photon detector and combines high efficiency near-infrared photon counting with the ability to resolve multiphoton absorption events.
Spatially resolved electron energy-loss spectroscopy of an interfacial structure at a Ti thin film Cu interconnect
Authors: Ikarashi Nobuyuki , Ueki Makoto , Hiroi Masayuki
Published: July 2003

We previously showed that a Ti layer insertion suppressed the stress-induced void formation in the Cu line under a via without increasing the electric resistance of the line [Ueki et al., Tech. Dig.-Int. Electron Devices Meet. 2002, 749 (2002)]. We describe here a detailed analysis of the interfacial structure between the Ti layer and the lower Cu line, and show that a very thin (about 10 nm) Cu–Ti alloy layer was formed at the interface. We thus infer that the Ti–Cu alloy formation played an important role in suppressing the voiding in the Cu line, while the electronic resistance should hardly be changed because the alloy layer was very thin.
Monte Carlo simulations of Hg0.7Cd0.3Te avalanche photodiodes and resonance phenomenon in the multiplication noise
Authors: Ma Feng , Li Xiaowei , Campbell Joe C. , Beck Jeffrey D. , Wan Chang-Feng , Kinch Michael A.
Published: July 2003

Monte Carlo simulations of Hg0.7Cd0.3Te avalanche photodiodes are presented. The simulated very low excess noise and exponential gain curve are consistent with those that have been experimentally observed and are consistent with the speculated large ratio of electron and hole impact ionization rates. The simulations suggest that there is a large difference between the scattering rates of electrons and holes, a direct consequence of the band structure. A resonance behavior in the excess noise factor at gain values near 2, 4, 8, and 16 is also revealed in the simulations. This effect is explained by comparing to the gain and noise of a photomultiplier tube.
Diffraction properties of two-dimensional photonic crystals
Authors: von Freymann G. , Koch W. , Meisel D. C. , Wegener M. , Diem M. , Garcia-Martin A. , Pereira S. , Busch K. , Schilling J. , Wehrspohn R. B. , Gösele U.
Published: July 2003

We show that the envelope of the diffraction efficiency of a two-dimensional photonic crystal can exhibit spectral regions of very small diffraction efficiency (<5×10−3), while in other regions, the diffraction efficiency is near unity. The experimental results on higher bands of hexagonal, silicon-based photonic crystals agree well with corresponding numerical calculations and highlight the prominent role of the surface termination, an aspect which cannot be described by the photonic band structure alone. We speculate about possible applications of such additional spectral filters in Raman and photoluminescence spectroscopy.
“Giant” Josephson proximity effect
Authors: Kresin V. , Ovchinnikov Yu. , Wolf S.
Published: July 2003

The “giant” Josephson current through the superconductor–normal–superconductor (S–N′–S) junction where the barrier N′ is an underdoped cuprate is explained. The thickness of N′ greatly exceeds the coherence length. The origin of this phenomenon is related to the origin of the metallic pseudogap state. The ability of a giant barrier to transfer a Josephson current is due to the inhomogeneous nature of the barrier and the presence of the superconducting “islands” embedded in the normal metallic matrix.
High-quality AlInN for high index contrast Bragg mirrors lattice matched to GaN
Authors: Carlin J.-F. , Ilegems M.
Published: July 2003

We report on the growth by metalorganic vapor phase epitaxy of high-quality Al1−xInxN layers and AlInN/GaN Bragg mirrors near lattice matched to GaN. Layers are grown on a GaN buffer layer with no cracks over full 2 in. sapphire wafers. The index contrast relative to GaN is around 7% for wavelengths ranging from 950 to 450 nm. We demonstrate the growth of a crack-free, 20 pairs Al0.84In0.16N/GaN distributed Bragg reflector centered at 515 nm with an over 90% reflectivity and a 35 nm stop band. The growth of high quality AlInN lattice matched to GaN may represent a breakthrough in GaN-based optoelectronics which is presently limited by the lack of a high-index-contrast and high-band gap lattice-matched material.
Photoluminescence of pyrochlore phase in SrBi2Ta2O9 thin films
Authors: Wang Y. P. , Ning H. F. , Zhou L. , Shen J. K. , Liu Z. G.
Published: July 2003

SrBi 2 Ta 2 O 9 thin films were prepared by pulsed laser deposition at different substrate temperatures. Photoluminescence (PL) has been detected at room temperature from the pyrochlore phase in the SrBi2Ta2O9 film deposited at 850 °C. The PL shows five luminescence bands of 330, 365, 407, 490, and 600 nm. And the PL excitation shows six excitation bands of 278, 330, 365, 407, 490, and 600 nm. The one-to-one correspondence of PL and PL excitation spectra reveals a band-to-band excitation and a multienergy-gap structure in the pyrochlore phase in SrBi2Ta2O9 films.
Nanoscale surface modification of glass using a 1064 nm pulsed laser
Authors: Theppakuttai Senthil , Chen Shaochen
Published: July 2003

We report a method to produce nanopatterns on borosilicate glass by a Nd:yttrium–aluminum–garnet laser (10 ns, 1064 nm), using silica nanospheres. Nonlinear absorption of the enhanced optical field between the spheres and glass sample is believed to be the primary reason for the creation of nanofeatures on the glass substrate. By shining the laser beam from the backside of the glass sample, the scattering effects are minimized and only the direct field enhancement due to the spheres is utilized for surface patterning. To confirm this, calculations based on the Mie scattering theory were performed, and the resulting intensity as a function of scattering angles are presented. The nanofeatures thus obtained by this method are 350 nm in diameter and the distance between them is around 640 nm, which is same as the size of spheres used.
Impact of ultraviolet-laser heating on the photoluminescence of ensembles of GaN microcrystallites
Authors: Bergman Leah , Chen Xiang-Bai , Feldmeier Joel , Purdy Andrew P.
Published: July 2003

We present optical analysis concerning the redshift of the photoluminescence (PL) of ensembles of GaN microcrystals. We found that the extent of the redshift depends on the laser power as well as on the size of the ensemble. For ensembles of ∼30 μm, the laser power in our experimental specification impacted the PL energy and caused a redshift of up to 120 meV. This phenomenon was not observed for a small ensemble of ∼1 μm or less. For the small ensemble, the PL redshift was negligible and depended weakly on the laser power; similar behavior was found in GaN thin film. The above findings were observed in the PL of GaN microcrystalline of wurtzite as well as the cubic structure. Our results point to a laser heating event occurring in the large ensemble; the emitted scattered light is confined among the microcrystallites thus causing heating. For a small ensemble, the light has a higher probability of diffusing outside the enclosure, and thus no laser heating occurs.
Developing an Infrastructure for Sharing Environmental Models
Authors: Crosier Scott J , Goodchild Michael F , Hill Linda L , Smith Terence R
Published: July 2003

The Internet and the World Wide Web offer a new solution to the problem of sharing scientific knowledge. Unlike traditional libraries based on print media, these new technologies facilitate the sharing of any information that can be expressed in a binary alphabet. Environmental models expressed as computer codes are instances of such information objects, and codes are the last of a four-stage process of model formulation. The transition to digital technologies changes the relative importance of the four stages. We present a six-stage model of the process of searching for information in distributed digital libraries. Search is made possible by metadata, which serve several distinct purposes, including description of the contents of information objects and their fitness for specified use, and the details needed to make use of information objects once accessed and retrieved. We present a straw-man structure for model metadata, explain the process used in its development, and invite its evaluation.
Urban Sprawl and the Cost of Public Services
Authors: Carruthers John I , Ulfarsson Gudmundur F
Published: July 2003

One of the principle criticisms of urban sprawl is that it undermines the cost-effective provision of public services. In this paper the authors examine whether or not this is true through an exploratory analysis of the influence that alternative development patterns have on twelve measures of public expenditure: total direct, capital facilities, roadways, other transportation, sewerage, trash collection, housing and community development, police protection, fire protection, parks, education, and libraries. The objectives of the analysis are threefold. First, the authors, through a background discussion, provide a brief overview of previous research on the relationship between urban development patterns and the cost of public services. Second, through empirical analysis, they examine how the character of urban development affects per capita public outlays in a cross-section of 283 metropolitan counties during the 1982–92 time period. A separate equation is estimated for each measure of expenditure, providing substantive evidence on how density, the spatial extent of urbanized land area, property value, and political fragmentation affect the cost of services. Finally, the authors use the results of the empirical analysis to develop a set of policy recommendations and directions for future research.
A GIS-based Decision Support System for Neighbourhood Greening
Authors: Randall Todd A , Churchill Cameron J , Baetz Brian W
Published: July 2003

A prototype decision support tool is described which provides options for the management of existing green spaces and for the establishment of new green space in suburban neighbourhoods. Suggested neighbourhood greening techniques include the naturalization of existing parks and increased foliage along streets and rights of way. The naturalization approach involves less frequent cutting in grassy fields, the introduction of native species, and the cessation of pesticide and herbicide applications. Increased plantings along streets and boulevards would improve the aesthetics of neighbourhoods, and may provide some relief from climatic extremes and urban heat island effects. The creation of new green space in already-built suburban neighbourhoods provides a longer term challenge to neighbourhood planners. Potential strategies include the introduction of small pocket parks and community gardens in vacant lots and school yards. Modelled outcomes from such neighbourhood greening strategies could be used in public meetings both to incorporate attitudes of the impacted community and to demonstrate benefits to a wider community. In particular, strategies should take into account issues of safety and perceived safety that commonly arise with the greater use of naturalization in green space management. The developed prototype decision support tool has been coded as an ArcView GIS extension and provides the opportunity to model and evaluate future scenarios better aligned to principles of sustainable community development. Three applications of this tool are discussed to illustrate some of the benefits of undertaking a range of neighbourhood greening strategies.
The Spatial Structure of Power: Traditional Villages and Houses in Korea
Authors: Choi Yoon Kyung
Published: July 2003

This paper is an attempt to understand the relationship between power and space constituted in traditional Korean society, a strictly status-oriented society. The author speculates on two traditional villages and houses within them. The analysis of the villages shows not only different patterns of spatial morphology but also different spatial strategies for consolidating power innate to each community. In Hahoe, with a spatial structure in the form of a concentric circle, the ruling class located their houses in more easily accessible and exposed spaces with the lower class's houses in secluded spaces. By contrast, in Yangdong, with its more complicated spatial and power structures, the ruling class appeared to locate their houses in an opposite way to that of Hahoe. The analysis of the positioning of important houses shows a basic principle of sustaining the power structure, that is, a strong congruence between consanguine hierarchy and spatial hierarchy. The analysis of the historical transition of the spatial structure of houses suggests a shift of power structure between male and female members within a family. The study clearly illustrates that a spatial structure can be understood as a historical text on which one can read a history of producing and sustaining the power structure within a society as shown in the analysis. The findings also imply that the power-space relationship can be meaningfully described only in its cultural context.
Revolutionizing the Core: GIS in the Planning Curriculum
Authors: Chapin Timothy S
Published: July 2003

Geographic information systems (GIS) have emerged over the past decade to become the most powerful and important computer application to hit the profession of planning. Although GIS is now used by most public sector planning agencies and private planning firms, planning schools have been slow to adapt their core curricula to ensure that all students gain some exposure to this technology before entering the job market. A review of the core curricula of accredited programs in North America revealed GIS to be a rare element of the core. This paper outlines potential reasons that GIS has been slow to emerge as an element in the planning core and offers some guidance on how to remedy this situation with a minimum of disruption to existing programs.
Modelling the Ecological Footprint of Green Travel Plans Using GIS and Network Analysis: From Metaphor to Management Tool?
Authors: Wood Graham
Published: July 2003

The author explores the use of ecological-footprint analysis for evaluating and communicating the environmental implications of transport alternatives within a company travel plan. From a case study of the Vodafone headquarters in Newbury, a component ecological footprint methodology is developed that employs geographic information systems (GIS) and network analysis to model the impacts of commuting activity prior to and after implementation of the company's ‘green travel plan’. Having provided an in-depth exploration of the footprint approach, the author considers the extent to which ecological footprinting may be used as a management tool for formulating, implementing, and refining company travel plans, in addition to its well-established role as a metaphor for communicating the consequences of consumption.
Making the outside World Dementia-Friendly: Design Issues and Considerations
Authors: Mitchell Lynne , Burton Elizabeth , Raman Shibu , Blackman Tim , Jenks Mike , Williams Katie
Published: July 2003

Design guidelines for dementia care homes have, in recent years, acknowledged the important role the internal environment plays in influencing the functional capabilities and emotional well-being of people with dementia. However, although the majority of people with dementia live in the community, similar guidance does not exist in relation to the outdoor environment. To identify aspects of design that should be considered in making the outside world dementia-friendly an analysis of the literature on the needs of older people with dementia and on current knowledge of best practice for internal environments was carried out. By drawing parallels with the outside environment this paper demonstrates that design solutions do potentially exist which would enable older people with dementia to continue to negotiate and use their local neighbourhoods. Familiarity, legibility, distinctiveness, accessibility, comfort, and safety all appear to have a major influence. Small street blocks with direct, connected routes and good visual access, varied urban form, and architectural features, and distinctive, unambiguous environmental cues could enhance successful orientation and wayfinding. Services and facilities within walking distance with adequate seating, lighting, shelter, and well-maintained, smooth, level, plain paving would ameliorate attending problems of physical frailty. The authors are now empirically testing these initial findings.
A 3-D Visual Method for Comparative Evaluation of Dense Built-up Environments
Authors: Fisher-Gewirtzman Dafna , Burt Michael , Tzamir Yigal
Published: July 2003

The work reported here is a contribution by the authors to the search for reliable metric method for spatial evaluation, related to human perception of ‘openness’ and to the development of evaluation tools for urban planning and design. A recent innovation, the ‘spatial openness index’ (SOI), a quantitative index, based on a three-dimensional visual analysis of space is applied here. This approach reflects the hierarchical order found in the urban environment: dwelling unit, building, neighbourhood, etc. This index expresses oppenness to natural light, air, and near and distant views, for each level in the hierarchical order. At the basis of this work is the assumption that the SOI is correlated with the ‘perceived density’, evaluated by people responding to alternative spatial configurations. A preliminary indication test was carried out in order to justify this assumption. In this test, groups of spatial configurations with equal built masses were ranked both by their calculated SOI and by statistical analysis of perceived density evaluated by participating individuals. Good agreement was found between pairs of results obtained for most of the spatial configurations.
Stabilization of the Activity of ATP-sensitive Potassium Channels by Ion Pairs Formed between Adjacent Kir6.2 Subunits
Authors: Lin Yu-Wen , Jia Taiping , Weinsoft Anne M. , Shyng Show-Ling
Published: July 2003

ATP-sensitive potassium (KATP) channels are formed by the coassembly of four Kir6.2 subunits and four sulfonylurea receptor subunits (SUR). The cytoplasmic domains of Kir6.2 mediate channel gating by ATP, which closes the channel, and membrane phosphoinositides, which stabilize the open channel. Little is known, however, about the tertiary or quaternary structures of the domains that are responsible for these interactions. Here, we report that an ion pair between glutamate 229 and arginine 314 in the intracellular COOH terminus of Kir6.2 is critical for maintaining channel activity. Mutation of either residue to alanine induces inactivation, whereas charge reversal at positions 229 and 314 (E229R/R314E) abolishes inactivation and restores the wild-type channel phenotype. The close proximity of these two residues is demonstrated by disulfide bond formation between cysteine residues introduced at the two positions (E229C/R314C); disulfide bond formation abolishes inactivation and stabilizes the current. Using Kir6.2 tandem dimer constructs, we provide evidence that the ion pair likely forms by residues from two adjacent Kir6.2 subunits. We propose that the E229/R314 intersubunit ion pairs may contribute to a structural framework that facilitates the ability of other positively charged residues to interact with membrane phosphoinositides. Glutamate and arginine residues are found at homologous positions in many inward rectifier subunits, including the G-protein–activated inwardly rectifying potassium channel (GIRK), whose cytoplasmic domain structure has recently been solved. In the GIRK structure, the E229- and R314-corresponding residues are oriented in opposite directions in a single subunit such that in the tetramer model, the E229 equivalent residue from one subunit is in close proximity of the R314 equivalent residue from the adjacent subunit. The structure lends support to our findings in Kir6.2, and raises the possibility that a homologous ion pair may be involved in the gating of GIRKs.
Side-chain Charge Effects and Conductance Determinants in the Pore of ClC-0 Chloride Channels
Authors: Chen Mei-Fang , Chen Tsung-Yu
Published: July 2003

The charge on the side chain of the internal pore residue lysine 519 (K519) of the Torpedo ClC-0 chloride (Cl−) channel affects channel conductance. Experiments that replace wild-type (WT) lysine with neutral or negatively charged residues or that modify the K519C mutant with various methane thiosulfonate (MTS) reagents show that the conductance of the channel decreases when the charge at position 519 is made more negative. This charge effect on the channel conductance diminishes in the presence of a high intracellular Cl− concentration ([Cl−]i). However, the application of high concentrations of nonpermeant ions, such as glutamate or sulfate (SO42−), does not change the conductance, suggesting that the electrostatic effects created by the charge at position 519 are unlikely due to a surface charge mechanism. Another pore residue, glutamate 127 (E127), plays an even more critical role in controlling channel conductance. This negatively charged residue, based on the structures of the homologous bacterial ClC channels, lies 4–5 Å from K519. Altering the charge of this residue can influence the apparent Cl− affinity as well as the saturated pore conductance in the conductance-Cl− activity curve. Amino acid residues at the selectivity filter also control the pore conductance but mutating these residues mainly affects the maximal pore conductance. These results suggest at least two different conductance determinants in the pore of ClC-0, consistent with the most recent crystal structure of the bacterial ClC channel solved to 2.5 Å, in which multiple Cl−-binding sites were identified in the pore. Thus, we suggest that the occupancy of the internal Cl−-binding site is directly controlled by the charged residues located at the inner pore mouth. On the other hand, the Cl−-binding site at the selectivity filter controls the exit rate of Cl− and therefore determines the maximal channel conductance.
Probing the Pore of ClC-0 by Substituted Cysteine Accessibility Method Using Methane Thiosulfonate Reagents
Authors: Lin Chia-Wei , Chen Tsung-Yu
Published: July 2003

ClC channels are a family of protein molecules containing two ion-permeation pores. Although these transmembrane proteins are important for a variety of physiological functions, their molecular operations are only superficially understood. High-resolution X-ray crystallography techniques have recently revealed the structures of two bacterial ClC channels, but whether vertebrate ClC channel pores are similar to those of bacterial homologues is not clear. To study the pore architecture of the Torpedo ClC-0 channel, we employed the substituted-cysteine-accessibility method (SCAM) and used charged methane thiosulfonate (MTS) compounds to modify the introduced cysteine. Several conclusions were derived from this approach. First, the MTS modification pattern from Y512C to E526C in ClC-0, which corresponds to residues forming helix R in bacterial ClC channels, is indeed consistent with the suggested helical structure. Second, the ClC-0 pore is more accessible to the negatively charged than to the positively charged MTS compound, a pore property that is regulated by the intrinsic electrostatic potential in the pore. Finally, attempts to modify the introduced cysteine at positions intracellular to the selectivity filter did not result in larger MTS modification rates for the open-state channel, suggesting that the fast gate of ClC-0 cannot be located at a position intracellular to the Cl− selectivity filter. Thus, the proposal that the glutamate side chain is the fast gate of the channel is applicable to ClC-0, revealing a structural and functional conservation of ClC channels between bacterial and vertebrate species.
External TEA Block of Shaker K+ Channels Is Coupled to the Movement of K+ Ions within the Selectivity Filter
Authors: Thompson Jill , Begenisich Ted
Published: July 2003

Recent molecular dynamic simulations and electrostatic calculations suggested that the external TEA binding site in K+ channels is outside the membrane electric field. However, it has been known for some time that external TEA block of Shaker K+ channels is voltage dependent. To reconcile these two results, we reexamined the voltage dependence of block of Shaker K+ channels by external TEA. We found that the voltage dependence of TEA block all but disappeared in solutions in which K+ ions were replaced by Rb+. These and other results with various concentrations of internal K+ and Rb+ ions suggest that the external TEA binding site is not within the membrane electric field and that the voltage dependence of TEA block in K+ solutions arises through a coupling with the movement of K+ ions through part of the membrane electric field. Our results suggest that external TEA block is coupled to two opposing voltage-dependent movements of K+ ions in the pore: (a) an inward shift of the average position of ions in the selectivity filter equivalent to a single ion moving ∼37% into the pore from the external surface; and (b) a movement of internal K+ ions into a vestibule binding site located ∼13% into the membrane electric field measured from the internal surface. The minimal voltage dependence of external TEA block in Rb+ solutions results from a minimal occupancy of the vestibule site by Rb+ ions and because the energy profile of the selectivity filter favors a more inward distribution of Rb+ occupancy.
Efficacy and Safety of Oral Pleconaril for Treatment of Colds Due to Picornaviruses in Adults: Results of 2 Double-Blind, Randomized, Placebo-Controlled Trials
Authors: Hayden Frederick G. , Herrington Darrell T. , Coats Teresa L. , Kim Kenneth , Cooper Ellen C. , Villano Stephen A. , Liu Siyu , Hudson Spencer , Pevear Daniel C. , Collett Marc , McKinlay Mark ,   Pleconaril Respiratory Infection Study Group
Published: July 2003

The novel capsid-binding antiviral pleconaril inhibits in vitro replication of most rhinoviruses and enteroviruses. Oral pleconaril treatment was studied in 2 parallel randomized, double-blind, placebo-controlled trials. Among 1363 picornavirus-infected participants (65%) in the studies combined, the median time to alleviation of illness was 1 day shorter for pleconaril recipients than for placebo recipients (P > .001). Cold symptom scores and frequency of picornavirus cultured from nasal mucus specimens were lower among pleconaril recipients by day 2 of treatment. No treatment effects were seen in those without picornavirus infection. Pleconaril was associated with a higher incidence of nausea (6% vs. 4%) and diarrhea (9% vs. 7%) and with small increases in mean serum cholesterol levels and platelet counts, compared with baseline measurements. A subsequent 6-week prophylaxis study found that pleconaril induces cytochrome P-450 3A enzymes, which metabolize a variety of drugs, including ethinyl estradiol. Early pleconaril treatment was well tolerated and significantly reduced the duration and severity of colds due to picornaviruses in adults.
The Fourier-Jacobi map and small representations
Authors: Weissman Martin
Published: July 2003

We study the “Fourier-Jacobi” functor on smooth representations of split, simple, simply-laced

p
p

-adic groups. This functor has been extensively studied on the symplectic group, where it provides the representation-theoretic analogue of the Fourier-Jacobi expansion of Siegel modular forms. Our applications are different from those studied classically with the symplectic group. In particular, we are able to describe the composition series of certain degenerate principal series. This includes the location of minimal and small (in the sense of the support of the local character expansion) representations as spherical subquotients.
Constructing rational maps from subdivision rules
Authors: Cannon J. , Floyd W. , Kenyon R. , Parry W.
Published: July 2003

Suppose

R

\mathcal {R}

is an orientation-preserving finite subdivision rule with an edge pairing. Then the subdivision map

σ

R

\sigma _{\mathcal {R}}

is either a homeomorphism, a covering of a torus, or a critically finite branched covering of a 2-sphere. If

R

\mathcal {R}

has mesh approaching

0
0

and

S

R

S_{\mathcal {R}}

is a 2-sphere, it is proved in Theorem 3.1 that if

R

\mathcal {R}

is conformal, then

σ

R

\sigma _{\mathcal {R}}

is realizable by a rational map. Furthermore, a general construction is given which, starting with a one-tile rotationally invariant finite subdivision rule, produces a finite subdivision rule

Q

\mathcal {Q}

with an edge pairing such that

σ

Q

\sigma _{\mathcal {Q}}

is realizable by a rational map.
Magma Emplacement and Remobilization Timescales Beneath Montserrat: Insights from Sr and Ba Zonation in Plagioclase Phenocrysts
Authors: ZELLMER G. F. , SPARKS R. S. J. , HAWKESWORTH C. J. , WIEDENBECK M.
Published: July 2003

Since 1995, the Soufrière Hills volcano on Montserrat, Lesser Antilles island arc, has erupted crystal-rich andesite magma that is geochemically very similar to the volcanic products of at least the last 174 ± 3 kyr (1σ). Nomarski images of plagioclase phenocrysts from six andesites erupted between 151 ± 4 ka (1σ) and AD 1999 reveal multiple crystal resorption events, and major shifts in anorthite content suggest that these are due to temperature variations. A model is developed that uses partitioning data for Ba and Sr to quantify the degree of intracrystalline disequilibrium of these elements with respect to anorthite content in 12 selected plagioclase phenocrysts. Intracrystalline diffusive equilibration of both Ba and Sr profiles is incomplete. However, local disequilibria do not consistently decrease towards crystal cores, i.e. potential differences between core and rim ages cannot be resolved, and so the timescale for crystal growth is considerably shorter than their residence time at magmatic temperatures. Using two-dimensional finite difference modelling of intracrystalline Sr diffusion as a first-order approximation of diffusion in three dimensions, it is possible to calculate bulk crystal residence times at the estimated Soufrière Hills magmatic temperature of 850°C. These range from ∼10 to ∼1200 years, independent of eruption age. Crystal residence times in the currently erupting andesite range from ∼15 to ∼320 years. Diffusion in three dimensions would result in shorter residence times. Such results can be explained by repeated intrusion of small volumes of andesitic material to upper-crustal levels, followed by rapid crystallization during degassing and rapid cooling. Remobilization of the intruded andesites by influx of hotter, more mafic magma, and amalgamation of andesites of different crystallization ages by associated convective processes, produced the currently erupting andesite that contains abundant inclusions of mafic magma. The short residence times of andesite magma in the upper crust, and the episodic character of volcanism at the Soufrière Hills with short periods of intense volcanism alternating with much longer periods of dormancy, are consistent with deep magma generation and storage and with episodic ascent to form ephemeral shallow chambers.
Losing ground? Tuvalu, the greenhouse effect and the garbage can
Authors: Connell John
Published: July 2003

Abstract:Greenhouse‐induced sea‐level rise (SLR) threatens coral atolls and particularly the few atoll states, such as Tuvalu. This central Pacific island microstate has minimal economic development options, and has increasingly perceived emigration and remittances as a development strategy, despite restricted opportunities. Internal migration, in search of wage employment, has brought almost half the national population to Funafuti atoll, with negative local environmental consequences. Short‐term scientific data show no evidence of SLR in Tuvalu, but the Government of Tuvalu has argued that there is visual evidence of SLR, through such consequences as increased erosion, flooding and salinity. Global media have increasingly emphasised a doomsday scenario, with Tuvalu as synecdoche and symbol of all threatened island environments. Environmental problems of diverse origin have been entirely attributed to distant processes causing SLR, in terms of ‘garbage can anarchy’ or a ‘conspiracy narrative’, and thus to distant causes. The Tuvalu Government has consequently sought compensation from, and migration opportunities in, distant states. The construction of apparently imminent hazard has potential domestic political and economic advantages, but environmental costs.
The ethnic geography of New Zealand: A decade of growth and change, 1991–2001
Authors: Johnston Ron J. , Poulsen Mike F. , Forrest Jim
Published: July 2003

Abstract: New Zealand's population growth of 10 per cent over the decade 1991–2001 resulted substantially from an increasing number of those claiming Pacific Island and Asian ethnicity, and to a lesser extent of the New Zealand Maori. Using census data for a comparable set of small areas with average populations of just over 100, this paper examines the changing geography of the four main ethnic categories – New Zealand European, New Zealand Maori, Pacific Island Peoples, and Asians – across the country as a whole and in its major settlements, especially Auckland. There is little extreme segregation of the three minority groups, but most of the Europeans live in areas where there is little exposure to those of other ethnicities. Most of the changes in segregation reflect the growth of Auckland's Pacific Island and, especially, Asian populations.
A family business: Women, children and smallholder sugar cane farming in Fiji
Authors: Carswell Sue
Published: July 2003

Abstract: This paper highlights the contribution of women and children to the sugar industry in Fiji by examining the importance of family labour in the historical development of the smallholder system and describing the present situation for the study participants. It is based on ethnographic fieldwork conducted during 1996–97, on the island of Vanua Levu in the northern region of Fiji. The twenty smallholder households in the study comprised both Fijian and Fiji Indian respondents who relied primarily on selling sugar cane for their cash income. How inequalities within the household in terms of allocation of labour and resources are legitimated is outlined. Resource distribution within the household in regards to two important issues for the sugar industry, land and trade liberalisation, are examined. In light of global trends in trade liberalisation and probable falls in sugar prices, future strategies for survival identified by Fijian and Fiji Indian smallholders are also discussed. The case study demonstrates that the sugar industry is still largely reliant on family labour and, particularly for low socio‐economic smallholders, the unremunerated labour of family members makes an essential contribution to the production of sugar cane.
Plan and market mismatch: Urban redevelopment in Beijing during a period of transition
Authors: Fang Ke , Zhang Yan
Published: July 2003

Abstract: With the emergence of the real estate market since 1990, the operation Beijing's economy has led to a re‐shaping of its inner city. By reviewing the Old and Dilapidated Housing Redevelopment (ODHR) programme in Beijing in the 1990s, this paper seeks to uncover the forces that led to the prevailing large‐scale urban redevelopment which induced serious environmental and socio‐economic problems. By analysing conflicts between major stakeholders of the ODHR programme, the paper finds that the root cause of these problems was embedded in the ‘mismatch of plan and market’ by which local officials and local developers utilised their privileges inherited from a planned economy to benefit from the emerging real estate markets. As a result, the hidden agenda of local elites was facilitated during the urban redevelopment process.
Fijian teachers on the move: Causes, implications and policies
Authors: Voigt‐Graf Carmen
Published: July 2003

Abstract: Education has increasingly come to be seen as a potent development tool, not least because the quality of the education system today affects a country's development for decades to come. The migration of teachers – both internationally by way of emigration and internally within countries – may adversely affect the quality of education especially in a country like Fiji with a limited human resource capacity. The emigration of workers, particularly of highly skilled workers who are endowed with high levels of human capital, has severe implications for a small country like Fiji. The emigration of teachers who are the largest professional group of migrants has led to the filling of vacancies by less experienced and junior teachers and is widely believed to have led to falling educational standards. In addition to international migration, there is substantial internal migration of teachers, mostly away from remote schools to urban areas. Rural schools find it particularly difficult to recruit and keep qualified and experienced personnel. In the process, rural areas have been drained of some of their best human resources. This article provides an overview of the scale of migration of secondary teachers from Fiji, raises development issues connected to the international and internal migration of teachers, describes policy responses that this migration has elicited and identifies areas requiring further research with a view to making policy recommendations as well as contributing to the literature on skilled migration in the Pacific.
Cross‐cultural interaction in the appraisal of disaster trauma in three Pacific Island countries
Authors: Taylor Antony J. W.
Published: July 2003

Abstract: The methods adopted in the appraisal of the trauma of three communities after different disasters in the South Pacific are described and discussed. The outcome affirms the need for non‐indigenous clinicians to be ready to adjust their concepts and methods to suit the cultural frameworks they encounter when they are invited abroad, and for local health professionals to be ready to share their knowledge and skills with their collegues from abroad. The outcome, it is argued, should improve the quality of service provided at all stages of disaster recovery, and still enable questions to be raised about matters of fundamental concern – such as the power of religious belief and of social justice in the process of healing. These questions were found to be of particular importance in the context of the South Pacific cultures.
Entrepreneurship and Unemployment in the UK
Authors: Thurik Roy
Published: July 2003

The influence of industrial structure, more specifically of entrepreneurship, is investigated on the level of unemployment in the UK. The question is to what extent entrepreneurship, i.e., business ownership can reduce the level of unemployment. The alleged differences between the managed and the entrepreneurial economy will be discussed as well as the links between entrepreneurship and unemployment. It will be concluded that the UK is a relative outlier when using a simple model of the relationship between unemployment and the rate of business ownership. The model is calibrated using recent data of some 23 OECD countries. It underestimates the decrease in unemployment in the UK in the period 1982–1990. Some arguments are brought forward why this might be the case.
Ricardo on Agricultural Improvements: a Note
Authors: Gehrke Christian , Kurz Heinz D. , Salvadori Neri
Published: July 2003

This note discusses the numerical examples of land saving and capital saving agricultural improvements Ricardo provided in the chapter on the rent of land in the Principles. Especially his illustration of the second kind of improvements met with fierce criticism. It is argued that Ricardo was not wrong in any substantive sense and that he could only be criticized for having changed the definition of rent as regards the timing of its payment from post to ante factum.
‘Independence’ and the founding of the Federal Reserve
Authors: Forder James
Published: July 2003

The Federal Reserve is ‘independent’, but contrary to opinions often expressed, it was not intended by its creators to be free from political control, although others involved in the debate over its establishment hoped that it would be. ‘Independence’ was independence from banking interests, not government. A gradual development of independence preceded a much greater acquisition of power during the Reagan Presidency. The lessons of history include the fact that with few changes in the Federal Reserve Act, its position in the American government has been dramatically transformed. Consequently, contrary to common practice in the economics literature, the ‘independence’ (from government) of a central bank evidently cannot be measured by tabulating characteristics of its statutes.
The Influence of Economists On the Federal Reserve Act
Authors: Caporale Barbara
Published: July 2003

Many economists helped to lay the groundwork for the Federal Reserve. Some did important work analyzing the problems of the National Bank System and arguing for formation of a central bank in economics journals. At least as importantly, if not more so, some economists took an active role in the reform movement and provided help and advice with the actual Congressional bill. Among these are J. Lawrence Laughlin, who chaired a group that actively raised support for the Federal Reserve Act in Congressional districts, and H. Parker Willis, who served as an expert for the subcommittee which wrote the original draft of what became the Federal Reserve Act. More broadly, this episode illustrates the impact that intellectuals and ideas can have on actual events; the analysis contemporary economists did in academic journals and in more political activities before and after the panic of 1907 guided the actual formation of a working central bank (JEL B10, N21).
Measuring central bank independence: a latent variables approach
Authors: De Haan Jakob , Leertouwer Erik , Meijer Erik , Wansbeek Tom
Published: July 2003

We argue that central bank independence (CBI) is a latent variable of which the various existing quantifications are imperfect indicators. We show how factor analysis techniques can be employed to assess the quality of the various indicators, and how an optimal weighting of the indicators can be obtained that gives the best approximation of CBI. We also show how these results can be utilized in models in which CBI is an explanatory variable. In contrast to the well‐known study ofCampillo and Miron (1997), we find that our CBI indicator is significantly related to inflation, also when various control variables are included.
China: Further Evidence on the Evolution of Stock Markets in Transition Economies
Authors: Li Xiao‐Ming
Published: July 2003

We revisit the weak‐form efficiency of China's stock markets by examining its changing behaviour over the entire history of the Shanghai and Shenzhen Stock Exchanges. The Kalman Filter technique is applied to the system consisting of a time‐varying AR model and an asymmetric TGARCH equation. The estimates of predictability combined with other non‐quantifiable, evolutionary characteristics of the markets are used to infer on their efficiency. It is shown that, at their initial development stages, both the Shanghai and Shenzhen markets were inefficient. However, the past decade saw a steady convergence of the two markets towards efficiency. An abnormal leverage effect is detected for Shanghai, but no strong evidence is found that there exists the information transmission between the two markets.
Dollar‐Deutschemark Polarisation: Comparing The Pound And Franc
Authors: Forder James , Hurn Stan
Published: July 2003

The extent to which movements in the sterling and franc bilateral exchange rates are associated with changes in the dollar‐deutschemark exchange rate is measured. In the case of the pound we find, in contrast to the impression that might be gained from previous studies, that its linkage to the dollar has been, since the late 1990s, as high as it was in the late 1970s. In the case of the franc, we find that it has for some time been a powerfully deutschemark‐linked currency. This calls into question the view that there has been significant ‘dollar‐deutschemark polarity’ with respect to the franc in the recent past. We suggest that policymaker guidance and market rules of thumb may partially explain the developments we observe.
Have output growth rates stabilised? evidence from the g‐7 economies
Authors: Mills Terence C. , Wang Ping
Published: July 2003

In this paper we consider an extension of Hamilton's Markov chain model of output growth that allows for a one‐time structural break in the hyperparameters. We fit this model to post‐war quarterly output growth data from the G‐7 economies and find evidence for such a structural break in each of them, although the break occurs at different times. The break is always associated with a decline in volatility and often with a narrowing of the mean growth differential between the expansionary and recessionary regimes. The results show that stabilisation has typically been achieved at the expense of a reduction in growth rates.
Why exporting countries agree to voluntary export restraints: the oligopolistic power of the foreign supplier
Authors: De Santis Roberto A.
Published: July 2003

This paper studies the impact of VER on an exporting country. It shows that a VER at the free‐trade level favours the concentration of industry, allows firms with an export licence to expand, causes the contraction of the size of the firms producing for the domestic market only, and raises the price mark‐up in the domestic market. The impact on welfare is indeterminate depending upon the effect on global efficiency. If a VER is binding, also the price mark‐up in the foreign market rises and this effect on terms of trade, ceteris paribus, is welfare improving. An applied general equilibrium model for Turkey supports the conjecture that with a VER the increased oligopolistic power of incumbent firms with an export licence, the higher price mark‐up in the domestic market and a possible social welfare gain, are the key elements in understanding the rationale behind VERs. However, if authorities induce firms to engage in unproductive profit‐seeking activities, rent dissipation occurs and the impact on social welfare becomes negative.