bluuebunny/crossref_metadata_2025 huggingface dataset:
Contemporary Percutaneous Coronary Intervention Versus Balloon Angioplasty for Multivessel Coronary Artery Disease
Authors: Srinivas V.S. , Brooks Maria Mori , Detre Katherine M. , King Spencer B. , Jacobs Alice K. , Johnston Janet , Williams David O.
Published: September 2002

Background—

This investigation compares the results of contemporary percutaneous coronary intervention (PCI) with standard balloon angioplasty among patients with multivessel coronary disease. Patients having balloon angioplasty in the Bypass Angioplasty Revascularization Investigation (BARI) and those within the Dynamic Registry meeting BARI eligibility criteria were studied.

Methods and Results—

Clinical features and in-hospital and 1-year outcomes of 857 BARI-eligible patients in the Dynamic Registry (contemporary PCI) were compared with the 904 randomized patients who underwent percutaneous transluminal coronary angioplasty in BARI. Compared with BARI patients, Registry patients had fewer lesions attempted (1.53 versus 2.56,
P
=0.001), more frequent single-vessel PCI (76% versus 33%,
P
<0.001), greater use of intracoronary stents (76% versus 1%,
P
<0.001), and GP IIb/IIIa receptor antagonist (24% versus 0%,
P
<0.001). Angiographic success was achieved more often among Registry patients (91% versus 72%,
P
<0.001), whereas abrupt closure (1.5% versus 9.5%,
P
<0.001) and in-hospital coronary artery bypass graft (CABG) (1.9% versus 10.2%,
P
<0.001) and myocardial infarction (0.8% versus 2.1%,
P
=0.025) were less common. No differences were observed in either in-hospital or 1-year death, but 1-year death/myocardial infarction was lower in the Registry. Registry patients had lower 1-year rates of subsequent CABG (8.6% versus 22.7%,
P
<0.001) and PCI (12.4% versus 22.5%,
P
<0.001). By multivariate analysis, contemporary PCI was independently associated with reduced risk for in-hospital CABG, 1-year CABG, and 1-year PCI.

Conclusions—

Among patients with multivessel disease, contemporary PCI resulted in safer and more durable revascularization. These results support the role of PCI for selected patients with multivessel coronary artery disease.
Endothelin Mediates Increased Pulmonary Vascular Tone in Patients With Heart Failure
Authors: Ooi Henry , Colucci Wilson S. , Givertz Michael M.
Published: September 2002

Background—

In patients with chronic heart failure (HF), the pulmonary circulation is a major source of endothelin-1 (ET), and ET levels correlate with pulmonary vascular resistance (PVR). The role of ET in causing pulmonary vasoconstriction in HF is not known, however, in part because of the confounding effects of ET receptor antagonists on systemic hemodynamics.

Methods and Results—

To directly test the hypothesis that ET causes pulmonary vasoconstriction in patients with HF, we infused the selective ET
A
receptor antagonist sitaxsentan at increasing rates (0.3125 to 10 mg/min) into a left lower-lobe segmental pulmonary artery in 8 patients with left ventricular (LV) systolic failure (LV ejection fraction, 24±4%) and 4 control subjects with normal LV function. Changes in local PVR distal to the infusion site were assessed by measuring the change in pulmonary blood flow velocity with a Doppler-tipped wire and the mean pulmonary artery pressure (MPAP). Total PVR at baseline was elevated in HF patients (177±23 dyne · s · cm
−5
) versus controls (89±21 dyne · s · cm
−5
;
P
<0.05). In patients with HF, sitaxsentan caused an infusion rate–dependent decrease in local PVR (
P
<0.05 versus baseline;
P
<0.05 versus controls). In contrast, sitaxsentan infusion had no effect on local PVR in controls. Heart rate, mean arterial pressure, cardiac index, and MPAP were not affected by sitaxsentan in either group.

Conclusion—

Selective ET
A
receptor blockade caused local pulmonary vasodilation in patients with HF, but not in control subjects with normal LV function. These data indicate that ET contributes to the secondary pulmonary hypertension associated with HF.
Red Wine Polyphenols Enhance Endothelial Nitric Oxide Synthase Expression and Subsequent Nitric Oxide Release From Endothelial Cells
Authors: Leikert Jürgen F. , Räthel Thomas R. , Wohlfart Paulus , Cheynier Véronique , Vollmar Angelika M. , Dirsch Verena M.
Published: September 2002

Background—

Population-based studies suggest a reduced incidence of morbidity and mortality from coronary heart disease caused by moderate and regular consumption of red wine. Endothelial nitric oxide (NO) is a pivotal vasoprotective molecule. This study examines the influence of red wine polyphenols on the regulation of endothelial nitric oxide synthase (eNOS) expression and subsequent NO synthesis, focusing on the putative long-lasting antiatherosclerotic effects of red wine.

Methods and Results—

Treatment (20 hours) of human umbilical vein endothelial cells (HUVECs) and of the HUVEC-derived cell line EA.hy926 with a alcohol-free red wine polyphenol extract (RWPE) led to a concentration-dependent (100 to 600 μg/mL), significant increase in NO release (up to 3.0-fold/HUVEC and 2.0-fold/EA.hy926) as shown by use of the fluorescent probe DAF-2. This effect was corroborated by the [
14
C]
l
-arginine/
l
-citrulline conversion assay in intact EA.hy926 cells. RWPE (20 hours, 100 to 600 μg/mL) also significantly increased eNOS protein levels up to 2.1-fold. Furthermore, we found an increased human eNOS promotor activity (up to 2-fold) in response to red wine polyphenols (18 hours, 100 to 600 μg/mL), as demonstrated by a luciferase reporter gene assay.

Conclusion—

We provide conclusive data showing for the first time that a RWPE increases eNOS expression and subsequent endothelial NO release. Increased active eNOS levels may antagonize the development of endothelial dysfunction and atherosclerosis, a hypothesis that supports the view that red wine indeed may have long-term protective cardiovascular properties mediated by its polyphenols.
Persistent Inhibition of Neointimal Hyperplasia After Sirolimus-Eluting Stent Implantation
Authors: Degertekin Muzaffer , Serruys Patrick W. , Foley David P. , Tanabe Kengo , Regar Evelyn , Vos Jeroen , Smits Peter C. , van der Giessen Wim J. , van den Brand Marcel , de Feyter Pim , Popma Jeffrey J.
Published: September 2002

Background—

Early results of sirolimus-eluting stent implantation showed a nearly complete abolition of neointimal hyperplasia. The question remains, however, whether the early promising results will still be evident at long-term follow-up. The objective of our study was to evaluate the efficiency of sirolimus-eluting stent implantation for up to 2 years of follow-up.

Methods and Results—

Fifteen patients with de novo coronary artery disease were treated with 18-mm sirolimus-eluting Bx-Velocity stents (Cordis) loaded with 140 μg sirolimus/cm
2
metal surface area in a slow release formulation. Quantitative angiography (QCA) and intravascular ultrasound (IVUS) were performed according to standard protocol. Sirolimus-eluting stent implantation was successful in all 15 patients. During the in-hospital course, 1 patient died of cerebral hemorrhage after periprocedural administration of abciximab, and 1 patient underwent repeat stenting after 2 hours because of edge dissection that led to acute occlusion. Through 6 months and up to 2 years of follow-up, no additional events occurred. QCA analysis revealed no significant change in stent minimal lumen diameter or percent diameter stenosis, and 3-dimensional IVUS showed no significant deterioration in lumen volume. In 2 patients, additional stenting was performed because of significant lesion progression remote from the sirolimus-eluting stent.

Conclusion—

Sirolimus-eluting stents showed persistent inhibition of neointimal hyperplasia for up to 2 years of follow-up.
Reading the Ventriloquist's Lips: The Performance Genre behind the Metaphor
Authors: Davis Charles B.
Published: September 2002

Ventriloquist performance foregrounds “voice” as the mark of an identity that is always under construction.
Guidance for Improving Life‐Cycle Design and Management of Milk Packaging
Authors: Keoleian Gregory A. , Spitzley David V.
Published: September 2002

Life‐cycle inventory and cost‐analysis tools applied to milk packaging offer guidelines for achieving better environmental design and management of these systems. Life‐cycle solid waste, energy, and costs were analyzed for seven systems including single‐use and refillable glass bottles, single‐use and refillable high‐density polyethylene (HDPE) bottles, paperboard gable‐top cartons, linear low‐density polyethylene (LLDPE) flexible pouches, and polycarbonate refillable bottles on a basis of 1,000 gal of milk delivered. In addition, performance requirements were also investigated that highlighted potential barriers and trade‐offs for environmentally preferable alternatives. Sensitivity analyses, indicated that material production energy, postconsumer solid waste, and empty container costs were key parameters for predicting life‐cycle burdens and costs. Recent trends in recycling rates, tipping fees, and recycled materials market value had minimal effect on the results. Inventory model results for life‐cycle solid waste and energy indicated the same rank order as results from previously published life‐cycle inventory studies of container systems.

Refillable HDPE and polycarbonate, and the flexible pouch were identified as the most environmentally preferable with respect to life‐cycle energy and solid waste. The greater market penetration of these containers may be limited by performance issues such as empty container storage, handling requirements, and deposit fees for refillables, and resealability and puncture resistance for the pouch.
Conoco and the Vapor Recovery Project: Using Innovation to Preserve Autonomy
Authors: Sharfman Mark , Ellington Rex T. , Meo Mark
Published: September 2002

We describe Conoco's closed‐loop approach to reducing undesirable emissions through vapor recovery at some of its natural gas production facilities near Corpus Christi, Texas. In response to the U.S. Clean Air Act Amendments of 1990 (CAAA), Conoco developed a technological solution that routed emissions from the facilities to fuel scrubbers and condensers to capture usable product and hazardous air pollutants. Usable product was sold. Nonsalable emissions were routed to on‐site equipment as fuel. The new technology was designed without power needs because electricity was not available. In completing these modifications, a closed system (approaching zero emissions) for these facilities was achieved. This innovation saved and earned money for the firm and allowed Conoco to retain its autonomy in these operations.

The solution was so effective that the air quality permits under the CAAA were not required for these production facilities, for a total out‐of‐pocket cost of 560,000 (plus earned revenue). The firm saved 2,535,000 in initial and 1,359,000 in annual permit costs and fees. The technology recovered 210,000/yr worth of vent gas as on‐site fuel and 3,633 barrels/yr of saleable condensate valued at 58,128/ yr. At the same time, it reduced its division environmental impact by 884 tons/year of nitrogen oxides, 2,366 tons/yr of volatile organic compounds, and 495 tons/yr of other hazardous air pollutants. Payout of this 560,000 investment was less than 2 years.
The Revenge of the Machines: On Modernity, Digital Technology and Animism
Authors: Aupers Stef
Published: September 2002

The classical assumption that scientific and technological progress are the main driving forces behind, what Weber called, the 'disenchantment of the western world', is basic knowledge in contemporary sociology. In this paper, however, it is argued that the implementation of digital technology also stimulates the religious, or more specific, animistic imagination. A qualitative analysis of

Wired

magazine (1993-2000) shows that various computer specialists, who are 'supposed' to be the pioneers of a rational, secular and disenchanted society, can be seen as 'technoanimists'. They consider our new technological surroundings as an intelligent, autonomous force and express feelings of humility. Exemplary for this phenomenon is a group of ICTexperts who refer to themselves as 'technopagans'. Paradoxically, the explanation for this unforeseen development of 're-enchantment' can be found in progress in the technological fields of Artificial Intelligence and Artificial Life. More generally, the ongoing process of rationalization seems to provide a good explanation for the contemporary emergence of technoanimism.
The Real in the Virtual—Speech, Self and Sex in the Realm of Pure Text
Authors: Koh Stella
Published: September 2002

'Virtual Reality' (VR) is a terminological umbrella for an assortment of technologies that are lumped together under one broad label. Internet Relay Chat (IRC) is a text-based VR that does not involve the use of data gloves and 3-D objects. IRC communication takes place via strings of text typed in by its users. Unlike face-to-face communication, IRC conversations lack the nonverbal component of language. This lack is, to some extent, rectified by the use of paralanguage techniques. Despite the paucity of nonverbal and social cues, IRC users are able to engage in a variety of activities. IRC culture is essentially a culture of play and imagination, as the users take advantage of the lack of information about other users to fill in idealised details and images of their own. However, IRC is not merely about play. Data on identity experimentation illustrate that some users leave IRC with newfound knowledge about their self-identities, and about the social world and its workings. With the IRC experience, boundaries between the 'real' and the 'virtual' are sometimes blurred, and some participants are no longer able to view the world in terms of binary divisions of 'real' and 'unreal' and 'human' and 'machine'.
The Culture of Technology of Singapore
Authors: Lim Alwyn
Published: September 2002

The objective of this paper is to map the sociological context in which the cultural economy of technology of Singapore exists. Taking a socio-historical perspective, this paper argues that the development of Singapore as a technological 'intelligent island' must take centre stage in relation to the sociological analysis of modern Singapore's political, economic, and socio-cultural structure. This involves a critique of theories of the information society and empirical research on East Asian developmental states. The aim is to chart the development of technology in Singapore, from its founding as a colonial port-city to its current status as an 'intelligent island', and to situate this development in its social context. In addressing the issue of the global expansion of localized technological knowledge hubs, I argue that while these technological 'hubs' are increasingly linked in complex political, economic and social networks, one must also account for the developmental trajectory of each particular 'hub' and to explain the socio-cultural complex of societies, which promote themselves as such. This paper intends to demonstrate how this construction of a technological nation state is neither a context-free project nor one that is free of complex historical antagonisms and contradictions.
Mineralogy for the new millennium
Authors: Parsons I.
Published: September 2002

This issue of Mineralogical Magazine – Journal of Mineral Sciences contains nine articles by distinguished mineralogists which were delivered as plenary lectures to the 18th General Meeting of the International Mineralogical Association held in Edinburgh in early September 2002. The IMA is the only truly international organization representing mineralogy, and is supported by subscriptions from 37 mineralogical societies world-wide. Its main activity is to hold a General Meeting every four years in one of the subscribing countries, and in 2002 the organization was handled jointly by a group based in Edinburgh and by the Mineralogical Society of Great Britain & Ireland. The organizers invited lecturers who we believed would provide an authoritative and exciting overview of the most vigorous areas of the science of mineralogy as we enter a new millennium. In this the lecturers have unquestionably succeeded and we are very grateful for the scholarship, time and effort that they have put into these presentations. Each article was checked by an expert, and I thank Ross Angel, Derek Bain, Bill Brown, Martin Lee, David Manning, Bryne Ngwenya and Alison Pawley for their help.
Sustaining Earth: Thoughts on the present and future roles of mineralogy in environmental science
Authors: Hochella M. F.
Published: September 2002

Sustaining Earth, in the face of both technology thrusts and population dynamics, depends on our ability to maintain a delicate balance between human-promoted planetary modification and decline thresholds for land (soils), water, atmosphere, and biological systems. Mineralogy, as much as any other single science, will be central to this process. A set of links between Earth sustainability issues and the science of mineralogy are formulated and discussed in this discourse. The strongest ties exist in the areas of mineral-water and mineral-atmosphere interactions. Minerals are also particularly important in human disease generation. In addition, due to the role of minerals as invaluable economic resources, the environmental consequences of mining also come into play. New subdisciplines have recently emerged to bring mineralogy even closer to Earth sustainability issues, particularly mineral-microbe interaction science and nanomineralogy
Minerals, metals and molecules: ore and environmental mineralogy in the new millennium
Authors: Vaughan D. J. , Pattrick R. A. D. , Wogelius R. A.
Published: September 2002

Aspects of the (bio)geochemical cycling of metals (including Fe, Cu, Pb, Zn, Hg, As, Sb, U, Tc, Np) at or near the Earth's surface are discussed with reference to the recent work of the authors. Key stages of the breakdown of metalliferous minerals, transport of metals as solution complexes or colloidal precipitates, and interaction of metals in solution with the surfaces of minerals are considered. Emphasis is on molecular-scale observations using techniques such as scanning probe microscopy, photoelectron and (synchrotron) X-ray spectroscopies. The importance of the biological/mineralogical interface is also emphasized with reference to the bacterial colonization of mineral surfaces and formation of biofilms, and their influence on mineral surface reactivity and flow of fluids through rocks and sediments. Also noted is the importance of relating molecular and micro-scale observations to macroscopic phenomena. Molecular-scale understanding is central to attempts to model many processes of relevance in mineral exploration and exploitation, and in the containment of hazardous wastes and remediation of polluted areas. Mineralogists have a central role to play in the relevant environmental sciences and technologies.
Quantitative mineralogy of sedimentary rocks with emphasis on clays and with applications to K-Ar dating
Authors: Środoń J.
Published: September 2002

Clays are the most complicated objects in quantitative mineral analysis of sedimentary rocks. Complex quantitative analysis of clays comprises four major steps: measuring bulk quantities, quantifying the mixed layering, determining the three-dimensional organization, and measuring the particle size. Computerization has resulted in major progress in all four areas during the last decade. X-ray diffraction remains the major tool of the quantitative studies of clays, supported by Fourier Transform Infrared Spectroscopy (bulk quantities), chemical analysis (bulk quantities) and electron microscopy (particle size). This contribution reviews recent developments in the techniques used for quantifying clays and their properties, and looks at the use of these quantification techniques in K-Ar dating of geological processes.
Mineral replacement reactions: from macroscopic observations to microscopic mechanisms
Authors: Putnis A.
Published: September 2002

Mineral replacement reactions take place primarily by dissolution-reprecipitation processes. Processes such as cation exchange, chemical weathering, deuteric alteration, leaching, pseudomorphism, metasomatism, diagenesis and metamorphism are all linked by common features in which one mineral or mineral assemblage is replaced by a more stable assemblage. The aim of this paper is to review some of these aspects of mineral replacement and to demonstrate the textural features they have in common, in order to emphasize the similarities in the underlying microscopic mechanisms. The role of volume change and evolution of porosity is explored both from natural microtextures and new experiments on model replacement reactions in simple salts. It is shown that the development of porosity is often a consequence of mineral replacement processes, irrespective of the relative molar volumes of parent and product solid phases. The key issue is the relative solubility of the phases in the fluid phase. Concepts such as coupled dissolution-precipitation, and autocatalysis are important in understanding these processes. Some consequences of porosity generation for metamorphic fluid flow as well as subsequent crystal growth are also discussed.
Microstructures of the silicates: key information about mineral reactions and a link with the Earth and materials sciences
Authors: Baronnet A. , Belluso E.
Published: September 2002

From a few examples, the first part of this paper discusses the use of transmission electron microscopy in characterizing arrested silicate reaction mechanisms in coherent rocks, including nucleation, crystal growth, and resorption events. Some attention is given to the role of reaction sites and strain. The second part of the paper addresses the wealth of mutual arrangement of serpentine tubules (chrysotilesl) found recently in serpentinite cracks, the result of hydration reactions. It is suggested that their great flexibility of association as fascinating mesostructures may indicate how veins formed and how they were filled. Micro- to nano-cracks might potentially serve as markers of brittle deformation in the submicron range, and therefore might document nanostructural geology. When possible the topological and self-assembly features observed for chrysotile are compared with those reported for graphene nanotubes.
Mineral physics: the atomic, mesoscopic and macroscopic perspective
Authors: Salje E. K. H. , Ríos S.
Published: September 2002

The macroscopic behaviour of minerals is not always directly related to their crystalline structure at the atomic scale but often depends explicitly on mesoscopic (nanometer–micrometer) features. This paper reviews various cases where the macroscopic phenomena differ from those of the bulk, with structural and chemical variations related to: domain walls, leading to enhanced or reduced transport properties; surfaces controlling growth morphologies; and radiation-damaged minerals where the interface between the amorphous and crystalline phase is believed to play a key role in hydrothermal leaching behaviour. Minerals explicitly discussed are: quartz, agate, hydroxylapatite, cordierite and metamict zircon.
Mineralogical and geochemical aspects of impact craters
Authors: Koeberl C.
Published: September 2002

The importance of impact cratering on terrestrial planets is obvious from the abundance of craters on their surfaces. On Earth, active geological processes rapidly obliterate the cratering record. To date only about 170 impact structures have been recognized on the Earth's surface. Mineralogical, petrographic, and geochemical criteria are used to identify the impact origin of such structures or related ejecta layers. The two most important criteria are the presence of shock metamorphic effects in mineral and rock inclusions in breccias and melt rocks, as well as the demonstration, by geochemical techniques, that these rocks contain a minor extraterrestrial component. There is a variety of macroscopic and microscopic shock metamorphic effects. The most important ones include the presence of planar deformation features in rock-forming minerals, high-pressure polymorphs (e.g. of coesite and stishovite from quartz, or diamond from graphite), diaplectic glass, and rock and mineral melts. These features have been studied by traditional methods involving the petrographic microscope, and more recently with a variety of instrumental techniques, including transmission electron microscopy, Raman spectroscopy, cathodoluminescence imaging and spectroscopy, and high-resolution X-ray computed tomography. Geochemical methods to detect an extraterrestrial component include measurements of the concentrations of siderophile elements, mainly of the platinum-group elements (PGEs), and, more recently, chromium and osmium isotopic studies. The latter two methods can provide confirmation that these elements are actually of meteoritic origin. The Cr isotopic method is also capable of providing information on the meteorite type. In impact studies there is now a trend towards the use of interdisciplinary and multi-technique approaches to solve open questions.
Application of synchrotron radiation and Kawai-type apparatus to various studies in high-pressure mineral physics
Authors: Irifune T.
Published: September 2002

A combination of Kawai-type multianvil apparatus and highly brilliant X-rays at the third generation synchrotron radiation facility (SPring-8) in Japan has been successfully applied to various studies in high-pressure mineral sciences such as determinations of phase transition boundaries, P–V–T relations of high-pressure phases, kinetics of phase transitions, structure and viscosity of melts. These studies are now comfortably made at pressures of ˜25 GPa and at temperatures to 2300°C, using the intense X-ray beam and the large capacity of the high-pressure apparatus at SPring-8. Moreover, efforts have been made to further extend the pressure limit using large sintered diamond anvils. Thus in situ X-ray observations are now possible at pressures to 50 GPa with the Kawai-type apparatus, which may be doubled in the near future when the potential of sintered diamond anvils is fully utilized. On the other hand, some problems, such as those related to pressure and temperature measurement, have been manifested in these studies. These should be overcome for further quantitative studies of the mineralogy of the Earth's deep interior based on these techniques.
New windows on earth and planetary interiors
Authors: Hemley R. J. , Mao H. K.
Published: September 2002

Recent diamond-anvil cell experiments are providing windows of unprecedented clarity on the interiors of the Earth, other planets, and their moons from highP-Tstudies of the materials that comprise these bodies. With recent advances in techniques, the component minerals can be examined with a growing array ofin situmethods over an expanding range of conditions that extend to hundreds of gigaspascals in pressure and thousands of degrees in temperature. Such investigations reveal that major, if not profound, changes in physical and chemical properties of these materials occur with depth. This information is crucial for understanding the materials basis of regional to global structure and processes documented by a wealth of recent observational and geophysical data. This paper reviews selected recent studies of major planet-forming minerals, focusing on key examples that illustrate different microscopic origins of macroscopic behaviour. This comparative mineralogical approach provides insight into phenomena occurring over a wide range of length scales. For terrestrial planets, the high-pressure behaviour of representative silicates, oxides and sulphides is examined. This includes the silicate perovskite assemblages that form the bulk of the Earth's lower mantle, for which a number of new findings concerning effects of non-stoichiometry and defect properties, pressure-induced electronic and magnetic transitions, and rheology have been obtained. HighP-Tstudies of Fe-Ni alloys, together with various light elements, provide constraints on the composition, structure and dynamics of terrestrial planet cores. Water is a key component of many planetary bodies; as ice it undergoes numerous high-pressure transformations and as a volatile component it is involved in potentially important highP-Tmineral reactions and is incorporated in dense mineral phases. Striking behaviour is observed in other molecular systems, including CO2and CH4and their mixtures with H2O; these form new phases, some relevant at the relatively modest conditions of deep marine sediments, others at the extreme states found in the deepest planetary interiors. Additional highP-Tinteractions between rare gases and ices and silicates are also documented. For the large planets, the most abundant ‘mineral’ is hydrogen, which has been shown to undergo novel mineral/gas reactions, possibly in cloud decks deep within the dense atmospheres of these bodies.
Untangling word webs: graph theory and the notion of density in second language word association networks
Authors: Wilks Clarissa , Meara Paul
Published: September 2002

This article examines the implications of the metaphor of the ‘vocabulary network’. It takes a formal approach to the exploration of this metaphor by applying the principles of Graph Theory to word association data in order to compare the relative densities of first language (L1) and second language (L2) lexical networks. Earlier graph theoretical research into L2 word associations is reviewed and methodological flaws in this work discussed. It describes the development of a new elicitation tool which is able to provide a means of quantifying lexical density levels. Levels of linkage in the L1 and L2 lexical networks are shown to be higher than previously assumed in the literature. It is argued that it will be helpful to develop a more complex interpretation of the notion of lexical density.
The role of ambiguity in second language change: the case of Mozambican African Portuguese
Authors: Gonçalves Perpétua
Published: September 2002

In this article, my point of departure is that language change is driven by acquisition, and I argue that the triggers for establishing the properties of language-specific grammars differ according to whether first language (L1) or second language (L2) acquisition is involved. The reason for this is that in L2 acquisition evidence about the target grammar may be ambiguous in ways which do not occur in L1 acquisition. To illustrate the argument, I present two case studies of Mozambican African Portuguese, a nonnative variety of Portuguese acquired during childhood by L1 speakers of Bantu languages. These case studies show that strings generated by the grammar of European Portuguese may trigger ‘wrong/new’ parameter values which, although nonexistent in the original grammatical system, are perfectly legitimate from the point of view of the speakers’ L1 grammars. In both cases, although the new parameter settings (NPSs) are not convergent with the target grammar, resetting is blocked because the new parameter values successfully analyse the input. The nonresetting of the ‘wrong/new’ parameter values in the direction of the target European norm can be attributed to the social context of language acquisition, where the original European model is considerably diluted, and the surface effects they set off appear to be denser since the L2 speakers are in the majority.
Structural Minimality, CP and the initial state in second language acquisition
Authors: Bhatt Rakesh M. , Hancin-Bhatt Barbara
Published: September 2002

This article considers the current debate on the initial state of second language acquisition (L2) and presents critical empirical evidence from Hindi learners of English as an L2 that supports the claim that the CP (complementizer phase) is initially absent from the grammar of L2 learners. Contrary to the predictions of Full Transfer (Schwartz and Sprouse, 1994; 1996), the data we present suggest that L2 learners start out without a CP and then graduate to a stage where overt expressions of CP (complementizer phase) are in fact manifest. Although the lack of evidence of CP appears to support the Minimal Trees/Partial Transfer (MT/PT) hypothesis (Vainikka and Young-Scholten, 1996a; 1996b), we show that the MT/PT hypothesis also fails to honour all the empirical facts.To account for the patterns in our data, we propose Structural Minimality - that clausal projections are IPs - as a hypothesis on the initial state of L2 acquisition. We argue that the Structural Minimality hypothesis accounts for the entire array CP-acquisition facts in Hindi-speaking learners of English as an L2.
The rediscovery of vocabulary
Authors: Meara Paul
Published: September 2002

This article reviews four recent books of current research in vocabulary acquisition. Vocabulary acquisition has moved from being a neglected backwater in second language acquisition (SLA) to a position of some importance, and this importance looks like increasing as lexical issues become more central to theoretical linguistics.The review suggests, however, that most vocabulary research in applied linguistics is based on a narrow linguistic agenda that was to a large extent defined by the concerns of the vocabulary control movement in the 1920s, particularly the work of H.E. Palmer and his successors (Smith, 1998; Institute of Research in Language Teaching, 2000). Current work in psycholinguistics and computational linguistics does not seem to have made much of an impact on the field, and this has led to a serious divergence between the theories of vocabulary acquisition that appear in these books, and the theories that are developing in other related fields.
Rapid volumetric calibration of coordinate measuring machines using a hole bar artefact
Authors: Lim C K , Burdekin M
Published: September 2002

The paper reports on the development of a new rapid volumetric accuracy calibration system for multiaxis coordinate measuring machines (CMMs). The system utilizes a calibrated mechanical artefact, in the form of a 540mm long I-beam hole bar. The 21 effective parametric error components for a three-axis machine can be obtained by probing the artefact when it is placed at 17 specified orientations within the measuring volume. The parametric errors are then further transformed into the CMM volumetric error by applying formulae derived from the rigid-body motion for the structural configuration of the CMM. Software has been developed to automate the probing of the artefact, data acquisition and the analysis of the parametric errors. Options for graphical and numerical data output of the volumetric error map is also included. Practical calibration tests and results from a moving bridge CNC (computer numerically controlled) CMM are shown, where the overall time for the calibration process, including equipment set-up time, was found to be less than two hours.
An automatic visual system for marble tile classification
Authors: Carrino L , Polini W , Turchetta S
Published: September 2002

The international market of ornamental stone has seen the use of materials quarrying from East Europe, Africa, Asia and South America, characterized by a low cost of labour. This event has embittered the competition in this field. Hence, it becomes fundamental to produce machined products of high quality in a more efficient way. This work aims to design and fulfil a prototype to automatically classify the Royal Perlato tiles of Coreno. It is based on artificial vision. The implemented hardware visual system is cheap because it is made up of components readily available and is easily obtainable by small and medium ornamental stone businesses. The developed software algorithm is based on a multifactor analysis of variance and a quadratic discriminant analysis. The experimental results show that the developed hardware and software system permits all the tiles of Royal Perlato of Coreno to be classified properly. Moreover, the developed system not only improves the efficiency of the selection but also reduces the controversies between the manufacturer and buyer, making tile classification more selective and increasing the number of qualitative classes taken into consideration. Finally, it allows the duplication on the selection line without altering data dispersion.
Analysis of fracture at the exit of engineering ceramics during the vibration drilling of a hole
Authors: Zhang Q H , Zhang J H , Sun D M , Zhang Q J , Deng J X
Published: September 2002

The widespread utilization of engineering ceramics has been limited by fracture in the machining process. A technical basis for avoiding fracture requires a fundamental understanding of the fracture mechanisms in machining. The present paper is intended to discuss the fracture mechanisms during the vibration drilling of holes in engineering ceramics. In this paper, the stress distribution during the vibration drilling of holes in ceramics has been analysed. The results show that, in the terminal period of vibration drilling, the stress on the periphery of the hole exit is at its maximum. It is the main reason for fracture at the exit of holes in engineering ceramics. The condition for no fracture at the exit is given, and an effective method is proposed to avoid such fracture.
A numerical analysis of a gas—tungsten arc welding considering the current density and temperature distribution on the electrode surface
Authors: Lee J H , Cho Y T , Na S-J
Published: September 2002

In numerical analysis of an arc plasma, the current density distribution and temperature distribution along the electrode surface are the most important boundary conditions, and a more accurate analysis can be achieved with a correct description of them. It was found that a distributed temperature condition taken from measured data makes isothermal contours broaden. The current density on the electrode surface was assumed to have a Gaussian distribution and its distribution parameters could be calculated for various electrode vertex angles. Analytically calculated distribution parameters helped the calculated temperature contours of the arc plasma to conform fairly well with experimental data.
Boundary model between casting and mould and its influence on the dimensional accuracy analysis of precision castings
Authors: Song Y , Yan Y , Zhang R , Lu Q , Xu D
Published: September 2002

In the past, when the solidification of castings has been simulated, the mould has not been considered or it has been treated as rigid while the boundary model between casting and mould has been considered. In qualitative analysis or semi-quantitative analysis, these assumptions may be reasonable. However, for numerical simulation of the dimensional accuracy of precision castings, which is a quantitative problem, these simplifications are no longer accurate. The boundary model between casting and mould directly influences the accuracy of numerical simulation of solidification for precision castings. This paper discusses in detail the boundary model between casting and mould and its influence on the accuracy of numerical simulation for precision castings. Three different boundary models are adopted to analyse the solidification process of a typical part, and the simulation results are compared with experimental results. The first boundary model assumes that the mould gives way. The second boundary model assumes that the mould is rigid and the casting is a thermoelastic-plastic deformable body. The third boundary model assumes that both the mould and the casting are elastic-plastic deformable bodies. The comparison between simulation and experimental results indicates that adopting the third kind of contact boundary model and analysing the mould and die both as deformable bodies would be more accurate for numerical simulation of dimensional accuracy in the solidification of precision castings. This contact boundary model, assuming both the mould and the casting to be elastic-plastic deformable bodies, is applied to the coupled thermomechanical analysis of the die of an automobile deck part. The simulation result also matches the practical casting quite well. This demonstrates that the contact boundary model adopted in this paper is accurate and feasible.
Enhanced strategy for milling corners
Authors: Choy H S , Chan K W
Published: September 2002

Tool path generation based on contour-parallel offset has many practical applications, especially in pocket milling. However, the tool path segments offset from the pocket boundary usually form many corners. In milling operation, these corners with accumulated material will have an adverse effect on milling performance. This paper proposes an improved numerically controlled (NC) tool path pattern for pocket milling. Bow-like tool path segments are appended to a conventional contour-parallel tool path at the corner positions. The cutter loops along the appended tool path so that the corner material is machined progressively in several passes. By adjusting the number of appended tool path loops, cutting resistance can be controlled. The proposed tool path generation for dealing with different corner shapes was implemented as an addon user function in a computer aided design/manufacture (CAD/CAM) system. Cutting tests confirmed that the proposed tool path pattern is useful for clearing accumulated material at pocket corners while maintaining a higher cutting stability.
A fuzzy basis channel-spanning performance measurement method for supply chain management
Authors: Chan F T S , Qi H J
Published: September 2002

Nowadays supply chain management has gained a tremendous amount of attention from both academics and practitioners. It provides an innovative management technology in order to assist enterprises to survive in the ever-increasing business competition and to sustain competitive advantages. Although there is an ever-increasing amount of literature addressing theories and practices of supply chain management, the existing performance measurement methods fail to provide significant assistance in supply chain development and an effective method is lacking. The objective of this paper is to propose an innovative channel-spanning performance measurement method from a system perspective. Fuzzy set theory is introduced to address the real situation in the judgement and evaluation processes. A simple example is given. The whole framework of this method is outlined with some suggestions, which, if appropriately applied, aims to facilitate performance improvement of supply chains.
Determination of the heat transfer coefficient at the workpiece—die interface for the forging process
Authors: Chang C C , Bramley A N
Published: September 2002

This paper describes an investigation of the determination of the heat transfer coefficient at the workpiece-die interface for the forging process. A surface thermocouple has been constructed to measure the temperature at the die surface, where a high pressure occurs, for the simple upsetting forging process. The process was also simulated by a commercial finite element package. The measured and predicted temperatures were then used in an inverse algorithm with an iterative approach to determine the interface heat transfer coefficient (IHTC). The results show that the predicted temperatures modelled by a constant IHTC at the rest-on-die stage were in good agreement with the experimental measurement. However, for the forging stage, the IHTC values vary significantly during the process. This has important consequences in the implementation of simulation software.
Optimized design with topology and shape optimization
Authors: Spath D , Neithardt W , Bangert C
Published: September 2002

International competition forces companies to use computer methods in order to accelerate the time-consuming development processes and further to improve the product quality. The use of numeric optimization methods can be very helpful to obtain ‘systematic and proper’ solution variants. Solutions that have been generated automatically provide the designer with new, previously unknown suggestions for problem solution.

These structural optimization tools have not yet been sufficiently integrated into the design process. Within a research project, software companies, research institutes and users are working on the integration of topology and shape optimization. This article presents an example of this process and describes the potential of the structure optimization tools based on the example of a machine tool.
Mechanical implementation services for rapid prototyping
Authors: Ahn S H , McMains S , Séquin C H , Wright P K
Published: September 2002

Inspired by the metal oxide system implementation service (MOSIS) project, CyberCut is an experimental fabrication testbed for an Internet-accessible, computerized prototyping and machining service. Client-designers can create mechanical components, generally using our web-based computer aided design (CAD) system (available at http://cad.berkeley.edu ), and submit appropriate files to the server at Berkeley for process planning. CyberCut then utilizes an open-architecture, computer numerical control (CNC) machine tool for fabrication. Rapid tool path planning, novel fixturing techniques and sensor-based precision machining techniques allow the designer to take delivery of a component machined from high-strength materials with good tolerances, e.g. ±0.002in (0.05 mm). There are also instances where the complex geometry of a component cannot be prototyped on our three-axis machine tool. For these components use is made of solid freeform fabrication (SFF) technologies such as fused deposition modelling (FDM) to build a prototype of the design. Based on experience with this testbed, a new characterization of types of relationship, or ‘couplings’, between design and manufacturing has been developed using the three classifications ‘loose and repetitive’, ‘stiff and one-way’ or ‘strong and bidirectional’. These three couplings represent different trade-offs between ‘design flexibility’ and ‘guaranteed manufacturability’.
Learning communities in remote retreat settings
Authors: Bersch Gretchen T. , Lund Carole L.
Published: October 2002

The formation of learning communities in remote retreat settings, specifically Yukon Island in Alaska, is the focus of this chapter. Testimony by learners and facilitators is included to enhance the discussion of the learning environment, the creation of community, and the learning process.
Attending to the peripheral world while driving
Authors: Crundall David , Underwood Geoffrey , Chapman Peter
Published: October 2002

Do inexperienced drivers see less of the world when driving? Previous research suggests that participants detect fewer peripheral targets while watching video clips of dynamic hazardous driving scenes due to increases in foveal demand (i.e. the presence of a hazard), increases in peripheral target eccentricity, and the lack of driving experience. The current study aimed to further explore the role of experience as a key factor in the potential narrowing of spatial attention, and the possibility of differences in the time course of attentional deployment. It was predicted that the amount of narrowing due to central processing demands would change as a function of driving experience, with more experienced drivers suffering less narrowing due to their mastery of central processing demands in road scenes. The data did not support the narrowing hypothesis, though they did support the alternative strategic difference between the driver groups in the time‐course of attentional deployment. Learners seem to suffer attentional degradation in extra‐foveal regions over a longer period of time whereas experienced drivers seem to invest peripheral attention at the hazard location in short but intense bursts. Copyright © 2002 John Wiley & Sons, Ltd.