Showing papers by "University of New South Wales published in 2000"

Comparison of Upper Gastrointestinal Toxicity of Rofecoxib and Naproxen in Patients with Rheumatoid Arthritis

Abstract: Background Each year, clinical upper gastrointestinal events occur in 2 to 4 percent of patients who are taking nonselective nonsteroidal antiinflammatory drugs (NSAIDs). We assessed whether rofecoxib, a selective inhibitor of cyclooxygenase-2, would be associated with a lower incidence of clinically important upper gastrointestinal events than is the nonselective NSAID naproxen among patients with rheumatoid arthritis. Methods We randomly assigned 8076 patients who were at least 50 years of age (or at least 40 years of age and receiving long-term glucocorticoid therapy) and who had rheumatoid arthritis to receive either 50 mg of rofecoxib daily or 500 mg of naproxen twice daily. The primary end point was confirmed clinical upper gastrointestinal events (gastroduodenal perforation or obstruction, upper gastrointestinal bleeding, and symptomatic gastroduodenal ulcers). Results Rofecoxib and naproxen had similar efficacy against rheumatoid arthritis. During a median follow-up of 9.0 months, 2.1 confirmed ga...

Stochastic Frontier Analysis

Abstract: 1. Introduction 2. Analytical foundations 3. The estimation of technical efficiency 4. The estimation and decomposition of cost efficiency 5. The estimation and decomposition of profit efficiency 6. The shadow price approach to the estimation and decomposition of economic efficiency 7. Incorporating exogenous influences on efficiency 8. The estimation of efficiency change and productivity change.

High performance scalable image compression with EBCOT

Abstract: A new image compression algorithm is proposed, based on independent embedded block coding with optimized truncation of the embedded bit-streams (EBCOT). The algorithm exhibits state-of-the-art compression performance while producing a bit-stream with a rich set of features, including resolution and SNR scalability together with a "random access" property. The algorithm has modest complexity and is suitable for applications involving remote browsing of large compressed images. The algorithm lends itself to explicit optimization with respect to MSE as well as more realistic psychovisual metrics, capable of modeling the spatially varying visual masking phenomenon.

Cyberostracism: Effects of being ignored over the Internet.

Abstract: Ostracism is such a widely used and powerful tactic that the authors tested whether people would be affected by it even under remote and artificial circumstances. In Study 1, 1,486 participants from 62 countries accessed the authors' on-line experiment on the Internet. They were asked to use mental visualization while playing a virtual tossing game with two others (who were actually computer generated and controlled). Despite the minimal nature of their experience, the more participants were ostracized, the more they reported feeling bad, having less control, and losing a sense of belonging. In Study 2, ostracized participants were more likely to conform on a subsequent task. The results are discussed in terms of supporting K. D. Williams's (1997) need threat theory of ostracism.

Antiretroviral Therapy in Adults: Updated Recommendations of the International AIDS Society–USA Panel

Abstract: Objective To update recommendations for antiretroviral therapy for adult human immunodeficiency virus type 1 (HIV-1) infection, based on new information and drugs that are available. Participants A 17-member international physician panel with antiretroviral research and HIV patient care experience initially convened by the International AIDS Society–USA in December 1995. Evidence Available clinical and basic science data including phase 3 controlled trials; data on clinical, virologic, and immunologic end points; research conference reports; HIV pathogenesis data; and panel expert opinion. Recommendations were limited to therapies available (US Food and Drug Administration approved) in 1999. Consensus Process The panel assesses new research reports and interim results and regularly meets to consider how the new data affect therapy recommendations. Recommendations are updated via full-panel consensus. Guidelines are presented as recommendations if the supporting evidence warrants routine use in the particular situation and as considerations if data are preliminary or incomplete but suggestive. Conclusions The availability of new antiretroviral drugs has expanded treatment choices. The importance of adherence, emerging long-term complications of therapy, recognition and management of antiretroviral failure, and new monitoring tools are addressed. Optimal care requires individualized management and ongoing attention to relevant scientific and clinical information in the field.

A Rose by Any Name? The Values Construct

Abstract: Definitional inconsistency has been epidemic in values theory and research. An abbreviated review of values-related theory and research is provided, and 5 aspects of the values construct that may have contributed to this inconsistency and the resulting lack of synthesis are discussed. A proposal for the process by which value priorities influence attitudinal and behavioral decisions also is outlined. Attitudinal and behavioral decisions are shown to be traceable to personal value priorities, although the link is indirect. The importance of 4 constructs in this process is highlighted. In the past, personal value systems, social value systems, worldviews, and ideologies each may have been given the generic label values.

Spin crossover phenomena in Fe(II) complexes

Abstract: The behaviour of spin crossover compounds is among the most striking and fascinating shown by relatively simple molecular species. This review aims to draw attention to the various ways in which spin crossover phenomena are manifested in iron(II) complexes, to offer some rationalisation for these, and to highlight their possible applications. Typical examples have been selected along with more recent ones in order to give an overall view of the scope and development of the area. The article is structured to provide the basic material for those who wish to enter the field of spin crossover.

Surface passivation of crystalline silicon solar cells: a review

Abstract: In the 1980s, advances in the passivation of both cell surfaces led to the first crystalline silicon solar cells with conversion efficiencies above 20%. With today's industry trend towards thinner wafers and higher cell efficiency, the passivation of the front and rear surfaces is now also becoming vitally important for commercial silicon cells. This paper presents a review of the surface passivation methods used since the 1970s, both on laboratory-type as well as industrial cells. Given the trend towards lower-cost (but also lower-quality) Si materials such as block-cast multicrystalline Si, ribbon Si or thin-film polycrystalline Si, the most promising surface passivation methods identified to date are the fabrication of a p–n junction and the subsequent passivation of the resulting silicon surface with plasma silicon nitride as this material, besides reducing surface recombination and reflection losses, additionally provides a very efficient passivation of bulk defects. Copyright © 2000 John Wiley & Sons, Ltd.

Determinants of User Innovation and Innovation Sharing in a Local Market

Abstract: It is known that end users of products and services sometimes innovate, and that innovations developed by users sometimes become the basis for important newcommercial products and services. It has also been argued and to some extent shown that such innovations will be found concentrated in a "lead user" segment of the user community. However, neither the characteristics of innovating users nor the scope of the community that they "lead" has been explored in depth.In this paper, we explore the characteristics of innovation, innovators, and innovation sharing by library users of OPAC information search systems in Australia. This market has capable users, but it is nonetheless clearly a "follower" with respect to worldwide technological advance. Wefind that 26% of users in this local market nonetheless do modify their OPACs in both major and minor ways, and that OPAC manufacturers judge many of these user modifications to be of commercial interest. We find that we can distinguish modifying from nonmodifying users on the basis of a number of factors, including their "leading-edge status" and their in-house technical capabilities. We find that many innovating users freely share their innovations with others, and find that we can distinguish users that share information about their modifications from users that do not. We conclude by considering some implications of our findings for idea generation practices in marketing.

A syndrome of lipoatrophy, lactic acidaemia and liver dysfunction associated with HIV nucleoside analogue therapy: contribution to protease inhibitor-related lipodystrophy syndrome.

Abstract: Background: Lipodystrophy (LD; peripheral lipoatrophy, central adiposity) hyperlipidaemia and insulin resistance often complicate protease inhibitor-containing antiretroviral therapy. Lipoatrophy and abdominal distension were observed in protease inhibitor-naive nucleoside analogue reverse transcriptase inhibitor (NRTI) recipients with lactic acidaemia and hepatic impairment, which are known NRTI-induced mitochondrial toxicities. Design and setting: Case-control study in a university-based outpatient clinic. Patients and methods: The patients studied included 14 NRTI recipients with lipoatrophy, 32 antiretroviral-naive patients without LD, 28 NRTI recipients without LD, 44 combined NRTI-protease inhibitor recipients without LD, and 102 NRTI-protease inhibitor recipients with LD. Data was obtained on body composition (questionnaire, physical examination, dual-energy x-ray absorptiometry and abdominal computerized tomography), with biochemical, lipid and glycaemic parameters. Results: The NRTI-LD syndrome was characterized by recent onset fatigue and nausea, peripheral lipoatrophy (6 kg loss over 4 months), abdominal distension (ascites ± hepatomegaly) and elevated lactate (4.6, 1.1, 1.2, 1.4 and 1.7 mmol/l, respectively; P< 0.0001) and liver enzymes. Cases without hepatic involvement also had lower body fat and greater lactate than unaffected controls. Metabolic disturbances and weight improved after cessation. The NRTI-LD syndrome differed from protease inhibitor-related LD syndrome by the presence of recent onset symptoms and weight loss, higher lactate and alanine aminotransferase, and lower albumin, cholesterol, triglycerides, glucose and insulin. In treated controls, current stavudine therapy, protease inhibitor duration, and lactic acidaemia were independently associated with both lipoatrophy and abdominal obesity; total NRTI duration was also associated with lipoatrophy, and lamivudine and protease inhibitor duration with buffalo hump. Conclusions: A syndrome of lipoatrophy, constitutional illness, lactic acidaemia and hepatic dysfunction can complicate NRTI therapy. Both protease inhibitor and NRTI therapies, particularly if associated with lactic acidaemia, contribute to LD syndrome, but have some distinguishable clinical and metabolic effects.

Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication

Abstract: Objectives—To compare the relative effects on performance of sleep deprivation and alcohol. Methods—Performance eVects were studied in the same subjects over a period of 28 hours of sleep deprivation and after measured doses of alcohol up to about 0.1% blood alcohol concentration (BAC). There were 39 subjects, 30 employees from the transport industry and nine from the army. Results—After 17‐19 hours without sleep, corresponding to 2230 and 0100, performance on some tests was equivalent or worse than that at a BAC of 0.05%. Response speeds were up to 50% slower for some tests and accuracy measures were significantly poorer than at this level of alcohol. After longer periods without sleep, performance reached levels equivalent to the maximum alcohol dose given to subjects (BAC of 0.1%). Conclusions—These findings reinforce the evidence that the fatigue of sleep deprivation is an important factor likely to compromise performance of speed and accuracy of the kind needed for safety on the road and in other industrial settings. (Occup Environ Med 2000;57:649‐655)

Contesting global governance : multilateral economic institutions and global social movements

Abstract: This book argues that increasing engagement between international institutions and sectors of civil society is producing a new form of global governance. The authors investigate 'complex multilateralism' by studying the relationship between three multilateral economic institutions (the IMF, World Bank, and World Trade Organization), and three global social movements (environmental, labour and women's movements). They provide a rich comparative analysis of the institutional response to social movement pressure, tracing institutional change, policy modification and social movement tactics as they struggle to influence the rules and practices governing trade, finance and development regimes. The contest to shape global governance is increasingly being conducted upon a number of levels and amongst a diverse set of actors. Analysing a unique breadth of institutions and movements, this book charts an important part of that contest.

When the Underwriter Is the Market Maker: An Examination of Trading in the IPO Aftermarket

Abstract: This paper examines aftermarket trading of underwriters and unaffiliated market makers in the three-month period after an IPO. We find that the lead underwriter is always the dominant market maker; he takes substantial inventory positions in the aftermarket trading, and co-managers play a negligible role in aftermarket trading. The lead underwriter engages in stabilization activity for less successful IPOs, and uses the overallotment option to reduce his inventory risk. Compensation to the underwriter arises primarily from fees, but aftermarket trading does generate positive profits, which are positively related to the degree of underpricing.

The Rush Hour: The Character of Leisure Time and Gender Equity

Abstract: The distribution of leisure time between the genders is contested. Becker's theory of specialization suggests that there is an underlying gender equity in leisure, while the competing view suggests that women are now bearing a "dual burden" as both family providers and family carers. Using indicators of the quantity and quality of leisure drawn from the Multinational Time Budget Data Archive and the Australian Time Use Survey, we find some support for both views. Although men and women have similar quantities of free time; when the character of leisure is considered the gap between genders reemerges.

Novel Photocatalyst: Titania-Coated Magnetite. Activity and Photodissolution

Abstract: Magnetic photocatalysts were synthesized by coating titanium dioxide particles onto colloidal magnetite and nano-magnetite particles. The photoactivity of the prepared coated particles was lower than that of single-phase TiO2 and was found to decrease with an increase in the heat treatment. These observations were explained in terms of an unfavorable heterojunction between the titanium dioxide and the iron oxide core, leading to an increase in electron−hole recombination. Interactions between the iron oxide core and the titanium dioxide matrix upon heat treatment were also seen as a possible cause of the observed low activities of these samples. Other issues considered include the physical and chemical characteristics of the samples, such as surface area and the presence of surface hydroxyl groups. Depending on the calcination conditions, these photocatalysts were found to suffer from varying degrees of photodissolution. Photodissolution tests revealed the greater the extent of the heat treatment, the low...

Seasoned Public Offerings: Resolution of the 'New Issues Puzzle'

Abstract: The 'new issues puzzle' is that stocks of common stock issuers subsequently underperform nonissuers matched on size and book-to-market ratio. With 7000 seasoned equity and debt issues, we document that issuer underperformance reflects lower systematic risk exposure for issuing firms relative to the matches. A consistent explanation is that, as equity issuers lower leverage, their exposures to unexpected inflation and default risks decrease, thus decreasing their stocks' expected returns relative to matched firms. Equity issues also significantly increase stock liquidity (turnover), again lowering expected returns relative to nonissuers. We conclude that the 'new issue puzzle' is explained by a failure of the matched-firm technique to provide a proper control for risk. This conclusion is robust to issue characteristics and the choice of factor model framework.

Turbo Codes: Principles and Applications

Abstract: List of Acronyms. List of Figures. List of Tables. Preface. 1. Introduction. 2. Block Codes. 3. Convolutional Codes. 4. Turbo Coding Performance Analysis and Code Design. 5. Trellis Based Decoding of Linear Codes. 6. Iterative Decoding. 7. Interleavers. 8. Turbo Coding for Fading Channels. 9. Turbo Trellis Coded Modulation Schemes. 10. Applications of Turbo Codes. Index.

Critically evaluated rate coefficients for free-radical polymerization, 2.. Propagation rate coefficients for methyl methacrylate

Abstract: Propagation rate coefficients, k(P), for free-radical polymerization of butyl acrylate (BA) previously reported by several groups are critically evaluated. All data were determined by the combination of pulsed-laser polymerization (PLP) and subsequent polymer analysis by size exclusion (SEC) chromatography. The PLP-SEC technique has been recommended as the method of choice for the determination of k(P) by the IUPAC Working Party on Modeling of Polymerization Kinetics and Processes. Application of the technique to acrylates has proven to be very difficult and, along with other experimental evidence, has led to the conclusion that acrylate chain-growth kinetics are complicated by intramolecular transfer (backbiting) events to form a mid-chain radical structure of lower reactivity. These mechanisms have a significant effect on acrylate polymerization rate even at low temperatures, and have limited the PLP-SEC determination of k(P) of chain-end radicals to low temperatures (<20 degreesC) using high pulse repetition rates. Nonetheless, the values for BA from six different laboratories, determined at ambient pressure in the temperature range of -65 to 20 degreesC mostly for bulk monomer with few data in solution, fulfill consistency criteria and show excellent agreement, and are therefore combined together into a benchmark data set. The data are fitted well by an Arrhenius relation resulting in a pre-exponential factor of 2.21 x 10(7) L (.) mol(-1) (.) s(-1) and an activation energy of 17.9 kJ (.) mol(-1). It must be emphasized that these PLP-determined k(P) values are for monomer addition to a chain-end radical and that, even at low temperatures, it is necessary to consider the presence of two radical structures that have very different reactivity. Studies for other alkyl acrylates do not provide sufficient results to construct benchmark data sets, but indicate that the family behavior previously documented for alkyl methacrylates also holds true within the alkyl acrylate family of monomers. [GRAPHICS] Arrhenius plot of propagation rate coefficients, k(P), for BA as measured by PLP-SEC.

Incorporating Learner Experience into the Design of Multimedia Instruction.

Abstract: In Experiment 1, inexperienced trade apprentices were presented with one of four alternative instructional designs: a diagram with visual text, a diagram with auditory text, a diagram with both visual and auditory text, or the diagram only. An auditory presentation of text proved superior to a visual-only presentation but not when the text was presented in both auditory and visual forms. The diagram-only format was the least intelligible to inexperienced learners. When participants became more experienced in the domain after two specifically designed training sessions, the advantage of a visual diagram-auditory text format disappeared. In Experiment 2, the diagram-only group was compared with the audio-text group after an additional training session. The results were the reverse of those of Experiment 1: The diagram-only group outperformed the audio-text group. Suggestions are made for multimedia instruction that takes learner experience into consideration. The experiments reported in this article were designed to test some hypotheses generated on the basis of cognitive load theory (see Sweller, 1999, and Sweller, van Merrienboer, & Paas, 1998, for a recent review of the theoretical model). Central to the theory is the notion that working memory limitations should be a major consideration when designing instruction. Although working memory considerations are often overlooked, storage and processing limita

rpoB-Based Microbial Community Analysis Avoids Limitations Inherent in 16S rRNA Gene Intraspecies Heterogeneity

Abstract: Contemporary microbial community analysis frequently involves PCR-amplified sequences of the 16S rRNA gene (rDNA). However, this technology carries the inherent problem of heterogeneity between copies of the 16S rDNA in many species. As an alternative to 16S rDNA sequences in community analysis, we employed the gene for the RNA polymerase beta subunit (rpoB), which appears to exist in one copy only in bacteria. In the present study, the frequency of 16S rDNA heterogeneity in bacteria isolated from the marine environment was assessed using bacterial isolates from the red alga Delisea pulchra and from the surface of a marine rock. Ten strains commonly used in our laboratory were also assessed for the degree of heterogeneity between the copies of 16S rDNA and were used to illustrate the effect of this heterogeneity on microbial community pattern analysis. The rock isolates and the laboratory strains were also used to confirm nonheterogeneity of rpoB, as well as to investigate the versatility of the primers. In addition, a comparison between 16S rDNA and rpoB PCR-DGGE (denaturing gradient gel electrophoresis)-based community analyses was performed using a DNA mixture of nine isolates from D. pulchra. Eight out of 14 isolates from D. pulchra, all rock isolates, and 6 of 10 laboratory strains displayed multiple bands for 16S rDNA when analyzed by DGGE. There was no indication of heterogeneity for either the rock isolates or the laboratory strains when rpoB was used for PCR-DGGE analysis. Microbial community pattern analysis using 16S rDNA PCR-DGGE showed an overestimation of the number of laboratory strains in the sample, while some strains were not represented. Therefore, the 16S rDNA PCR-DGGE-based community analysis was proven to be severely limited by 16S rDNA heterogeneity. The mixture of isolates from D. pulchra proved to be more accurately described using rpoB, compared to the 16S rDNA-based PCR-DGGE.

Membrane separation bioreactors for wastewater treatment

Abstract: With continuing depletion of fresh water resources, focus has shifted more toward water recovery, reuse, and recycling, which require an extension of conventional wastewater treatment technologies. Downstream external factors like stricter compliance requirements for wastewater discharge, rising treatment costs, and spatial constraints necessitate renewed investigation of alternative technologies. Coupled with biological treatment processes, membrane technology has gained considerable attention due to its wide range of applicability and the performance characteristics of membrane systems that have been established by various investigations and innovations during the last decade. This article summarizes research efforts and presents a review of the how and why of their development and applications. The focus is on appraising and comparing technologies on the basis of their relative merits and demerits. Additional facts and figures, especially regarding process parameters and effluent quality, are used to e...

Computer simulation of the packing of fine particles

Abstract: This paper presents a simulation study of the packing of uniform fine-spherical particles where the van der Waals force is dominant. It is shown that porosity increases with the decreases of particle size from about 100 to 1 mm and the simulated relationship can match the literature data well. The packing structure of fine particles is qualitatively depicted by illustrative pictures and quantified in terms of radial distribution function, angular distribution, and coordination number. The results indicate that in line with the increase in porosity, the first component of the split second peak and then the other peaks beyond the second one in the radial distribution function gradually vanish; the first peak becomes narrower, with a sharp decrease to the first minimum. As particle size decreases, the peaks at 120 degrees and then 60 degrees in the angular distribution will gradually vanish; the coordination number distribution shifts to the left and becomes narrower. The mean coordination number can decrease to a value as low as two for 1 mm particles, giving a very loose and chainlike structure. The interparticle forces acting on individual particles in a stable packing are analyzed and shown to be related to the packing properties.