Showing papers by "University of Melbourne published in 2003"

Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case series unselected for family history: a combined analysis of 22 studies

Abstract: Germline mutations in BRCA1 and BRCA2 confer high risks of breast and ovarian cancer, but the average magnitude of these risks is uncertain and may depend on the context. Estimates based on multiple-case families may be enriched for mutations of higher risk and/or other familial risk factors, whereas risk estimates from studies based on cases unselected for family history have been imprecise. We pooled pedigree data from 22 studies involving 8,139 index case patients unselected for family history with female (86%) or male (2%) breast cancer or epithelial ovarian cancer (12%), 500 of whom had been found to carry a germline mutation in BRCA1 or BRCA2. Breast and ovarian cancer incidence rates for mutation carriers were estimated using a modified segregation analysis, based on the occurrence of these cancers in the relatives of mutation-carrying index case patients. The average cumulative risks in BRCA1-mutation carriers by age 70 years were 65% (95% confidence interval 44%-78%) for breast cancer and 39% (18%-54%) for ovarian cancer. The corresponding estimates for BRCA2 were 45% (31%-56%) and 11% (2.4%-19%). Relative risks of breast cancer declined significantly with age for BRCA1-mutation carriers (P trend.0012) but not for BRCA2-mutation carriers. Risks in carriers were higher when based on index breast cancer cases diagnosed at <35 years of age. We found some evidence for a reduction in risk in women from earlier birth cohorts and for variation in risk by mutation position for both genes. The pattern of cancer risks was similar to those found in multiple-case families, but their absolute magnitudes were lower, particularly for BRCA2. The variation in risk by age at diagnosis of index case is consistent with the effects of other genes modifying cancer risk in carriers.

An introduction to MCMC for machine learning

Abstract: This purpose of this introductory paper is threefold. First, it introduces the Monte Carlo method with emphasis on probabilistic machine learning. Second, it reviews the main building blocks of modern Markov chain Monte Carlo simulation, thereby providing and introduction to the remaining papers of this special issue. Lastly, it discusses new interesting research horizons.

Observation of a Narrow Charmoniumlike State in Exclusive B±→K±π+π-J/ψ Decays

Abstract: We report the observation of a narrow charmoniumlike state produced in the exclusive decay process B+/--->K+/-pi(+)pi(-)J/psi. This state, which decays into pi(+)pi(-)J/psi, has a mass of 3872.0+/-0.6(stat)+/-0.5(syst) MeV, a value that is very near the M(D0)+M(D(*0)) mass threshold. The results are based on an analysis of 152M B-Bmacr; events collected at the Upsilon(4S) resonance in the Belle detector at the KEKB collider. The signal has a statistical significance that is in excess of 10sigma.

Activity–composition relations for phases in petrological calculations: an asymmetric multicomponent formulation

Abstract: For petrological calculations, including geothermobarometry and the calculation of phase diagrams (for example, P–T petrogenetic grids and pseudosections), it is necessary to be able to express the activity–composition (a–x) relations of minerals, melt and fluid in multicomponent systems Although the symmetric formalism—a macroscopic regular model approach to a–x relations—is an easy-to-formulate, general way of doing this, the energetic relationships are a symmetric function of composition We allow asymmetric energetics to be accommodated via a simple extension to the symmetric formalism which turns it into a macroscopic van Laar formulation We term this the asymmetric formalism (ASF) In the symmetric formalism, the a–x relations are specified by an interaction energy for each of the constituent binaries amongst the independent set of end members used to represent the phase In the asymmetric formalism, there is additionally a "size parameter" for each of the end members in the independent set, with size parameter differences between end members accounting for asymmetry In the case of fluid mixtures, for example, H2O–CO2, the volumes of the end members as a function of pressure and temperature serve as the size parameters, providing an excellent fit to the a–x relations In the case of minerals and silicate liquid, the size parameters are empirical parameters to be determined along with the interaction energies as part of the calibration of the a–x relations In this way, we determine the a–x relations for feldspars in the systems KAlSi3O8–NaAlSi3O8 and KAlSi3O8–NaAlSi3O8–CaAl2Si2O8, for carbonates in the system CaCO3–MgCO3, for melt in the melting relationships involving forsterite, protoenstatite and cristobalite in the system Mg2SiO4–SiO2, as well as for fluids in the system H2O–CO2 In each case the a–x relations allow the corresponding, experimentally determined phase diagrams to be reproduced faithfully The asymmetric formalism provides a powerful and flexible way of handling a–x relations of complex phases in multicomponent systems for petrological calculations

A Comparison of Outcomes With Angiotensin-Converting--Enzyme Inhibitors and Diuretics for Hypertension in the Elderly

Abstract: Background Treatment of hypertension with diuretics, beta-blockers, or both leads to improved outcomes. It has been postulated that agents that inhibit the renin–angiotensin system confer benefit beyond the reduction of blood pressure alone. We compared the outcomes in older subjects with hypertension who were treated with angiotensin-converting–enzyme (ACE) inhibitors with the outcomes in those treated with diuretic agents. Methods We conducted a prospective, randomized, open-label study with blinded assessment of end points in 6083 subjects with hypertension who were 65 to 84 years of age and received health care at 1594 family practices. Subjects were followed for a median of 4.1 years, and the total numbers of cardiovascular events in the two treatment groups were compared with the use of multivariate proportional-hazards models. Results At base line, the treatment groups were well matched in terms of age, sex, and blood pressure. By the end of the study, blood pressure had decreased to a similar exte...

Metal-Protein Attenuation With Iodochlorhydroxyquin (Clioquinol) Targeting Aβ Amyloid Deposition and Toxicity in Alzheimer Disease: A Pilot Phase 2 Clinical Trial

Abstract: Background Alzheimer disease (AD) may be caused by the toxic accumulation of β-amyloid (Aβ). Objective To test this theory, we developed a clinical intervention using clioquinol, a metal-protein–attenuating compound (MPAC) that inhibits zinc and copper ions from binding to Aβ, thereby promoting Aβ dissolution and diminishing its toxic properties. Methods A pilot phase 2 clinical trial in patients with moderately severe Alzheimer disease. Results Thirty-six subjects were randomized. The effect of treatment was significant in the more severely affected group (baseline cognitive subscale score of the Alzheimer's Disease Assessment Scale, ≥25), due to a substantial worsening of scores in those taking placebo compared with minimal deterioration for the clioquinol group. Plasma Aβ 42 levels declined in the clioquinol group and increased in the placebo group. Plasma zinc levels rose in the clioquinol-treated group. The drug was well tolerated. Conclusion Subject to the usual caveats inherent in studies with small sample size, this pilot phase 2 study supports further investigation of this novel treatment strategy using a metal-protein–attenuating compound.

Neurobehavioral outcomes of school-age children born extremely low birth weight or very preterm in the 1990s.

Abstract: ContextThe outcome into school age of regional cohorts of children born in the 1990s with birth weights less than 1000 g (extremely low birth weight, ELBW) or earlier than 28 weeks' gestation (very preterm) is not known.ObjectiveTo determine the cognitive, educational, and behavioral outcome of ELBW or very preterm infants born in the 1990s compared with normal birth weight (NBW) controls.DesignRegional cohort study.SettingVictoria, Australia.ParticipantsThe ELBW or very preterm cohort was composed of 298 consecutive survivors born during 1991-1992. The NBW cohort was composed of 262 randomly selected children with birth weights of more than 2499 g.Main Outcome MeasuresCognitive ability, educational progress, and behavioral problems.ResultsThe follow-up rates from birth to 8 years of age for survivors were 92.3% (275/298) for the ELBW or very preterm cohort and 85.1% (223/262) for the NBW cohort. The ELBW or very preterm children scored significantly below NBW controls on full-scale IQ (mean difference, –9.4; 95% confidence interval [CI], –12.1 to –6.7; P<.001) and indices of verbal comprehension (mean difference, –6.8; 95% CI, –9.5 to –4.2; P<.001), perceptual organization (mean difference, –9.9; 95% CI, –12.7 to –7.2; P<.001), freedom from distractibility (mean difference, –8.1; 95% CI, –10.8 to –5.5; P<.001), and processing speed (mean difference, –6.7; 95% CI, –9.4 to –4.0; P<.001). The ELBW or very preterm children performed significantly worse than the NBW cohort on tests of reading (mean difference, –6.7; 95% CI, –9.5 to –3.9; P<.001), spelling (mean difference, –5.6; 95% CI, –8.0 to –3.3; P<.001), and arithmetic (mean difference, –8.8; 95% CI, –11.3 to –6.2; P<.001). Attentional difficulties, internalizing behavior problems, and immature adaptive skills were more prevalent in the ELBW or very preterm cohort.ConclusionSchool-aged ELBW or very preterm children born in the 1990s continue to display cognitive, educational, and behavioral impairments.

PAR reduction in OFDM via active constellation extension

Abstract: The high peak-to-average power ratio (PAR) in orthogonal frequency division multiplexing (OFDM) modulation systems can significantly reduce power efficiency and performance. Methods exist which alter or introduce new signal constellations to combat large signal peaks. We present a new PAR-reduction method that dynamically extends outer constellation points in active (data-carrying) channels, within margin-preserving constraints, in order to minimize the peak magnitude. This scheme simultaneously decreases the bit error rate slightly while substantially reducing the peak magnitude of an OFDM transmit block. Furthermore, there is no loss in data rate and, unlike other methods, no side information is required. PAR reduction for an approximated analog signal is considered, and about a 4.6 dB reduction at a 10/sup -5/ symbol-clip probability is obtained for 256-channel QPSK OFDM. The results show great promise for use in commercial systems.

Improving precision and reducing bias in biological surveys: estimating false‐negative error rates

Abstract: The use of presence/absence data in wildlife management and biological surveys is widespread. There is a growing interest in quantifying the sources of error associated with these data. We show that false-negative errors (failure to record a species when in fact it is present) can have a significant impact on statistical estimation of habitat models using simulated data. Then we introduce an extension of logistic modeling, the zero-inflated binomial (ZIB) model that permits the estimation of the rate of false-negative errors and the correction of estimates of the probability of occurrence for false-negative errors by using repeated visits to the same site. Our simulations show that even relatively low rates of false negatives bias statistical estimates of habitat effects. The method with three repeated visits eliminates the bias, but estimates are relatively imprecise. Six repeated visits improve precision of estimates to levels comparable to that achieved with conventional statistics in the absence of false-negative errors. In general, when error rates are ≤50% greater efficiency is gained by adding more sites, whereas when error rates are >50% it is better to increase the number of repeated visits. We highlight the flexibility of the method with three case studies, clearly demonstrating the effect of false-negative errors for a range of commonly used survey methods.

Working at a Cynical Distance: Implications for Power, Subjectivity and Resistance

Abstract: Subjectivity and power are important concepts for understanding corporate culture engineering in critical organization studies. Although recent research indicates that many workers do identify with the organization as a result of these management strategies, they have also shown that some workers resist through dis-identification, in particular cynicism. Managerialist literature views cynicism as a psychological defect that needs to be `corrected', while a radical humanist approach constructs cynicism as a defence mechanism, a way of blocking the colonization of a pre-given self. We highlight a third and increasingly dominant perspective that suggests cynicism is a process through which employees dis-identify with cultural prescriptions, yet often still perform them. Cynical employees have the impression that they are autonomous, but they still practice the corporate rituals nonetheless. We label this the `ideology' interpretation because in dis-identifying with power, it is inadvertently reproduced at th...

Resources, Knowledge and Influence: The Organizational Effects of Interorganizational Collaboration*

Abstract: Inter-organizational collaboration has been linked to a range of important outcomes for collaborating organizations. The strategy literature emphasizes the way in which collaboration between organizations results in the sharing of critical resources and facilitates knowledge transfer. The learning literature argues that collaboration not only transfers existing knowledge among organizations, but also facilitates the creation of new knowledge and produce synergistic solutions. Finally, research on networks and interorganizational politics suggests that collaboration can help organizations achieve a more central and influential position in relation to other organizations. While these effects have been identified and discussed at some length, little attention has been paid to the relationship between them and the nature of the collaborations that produce them. In this paper, we present the results of a qualitative study that examines the relationship between the effects of interorganizational collaboration and the nature of the collaborations that produce them. Based on our study of the collaborative activities of a small, nongovernmental organization (NGO) in Palestine over a four-year period, we argue that two dimensions of collaboration – embeddedness and involvement – determine the potential of a collaboration to produce one or more of these effects.

Normative Data From the Cantab. I: Development of Executive Function Over the Lifespan

Abstract: The study of executive function within a developmental framework has proven integral to the advancement of knowledge concerning the acquisition and decline of higher skill processes. Still in its early stages, there exists a discontinuity in the literature between the exploration of executive capacity in young children and the elderly. Research of age-related differences utilising a lifespan approach has been restricted by the lack of assessment tools for the measurement of executive skills that are applicable across all age levels. This paper addresses these issues using the computer-based Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify periods of development in executive capacities using a normative sample of 194 participants ranging in age from 8 to 64 years. Findings of executive function in children as young as 8 years of age were extended, with functional gains found in the efficiency of working memory capacity, planning and problem-solving abilities, between the ages of 15 and 19 years and again at 20-29 years of age. Cognitive flexibility was assessed at adult-levels in even the youngest children. Declines in performance on all tasks were revealed for the 50-64 year old sample, providing support for the vulnerability of executive skills to normal aging.

New ages for human occupation and climatic change at Lake Mungo, Australia

Abstract: Australia's oldest human remains, found at Lake Mungo, include the world's oldest ritual ochre burial (Mungo III) and the first recorded cremation (Mungo I). Until now, the importance of these finds has been constrained by limited chronologies and palaeoenvironmental information. Mungo III, the source of the world's oldest human mitochondrial DNA, has been variously estimated at 30 thousand years (kyr) old, 42-45 kyr old and 62 +/- 6 kyr old, while radiocarbon estimates placed the Mungo I cremation near 20-26 kyr ago. Here we report a new series of 25 optical ages showing that both burials occurred at 40 +/- 2 kyr ago and that humans were present at Lake Mungo by 50-46 kyr ago, synchronously with, or soon after, initial occupation of northern and western Australia. Stratigraphic evidence indicates fluctuations between lake-full and drier conditions from 50 to 40 kyr ago, simultaneously with increased dust deposition, human arrival and continent-wide extinction of the megafauna. This was followed by sustained aridity between 40 and 30 kyr ago. This new chronology corrects previous estimates for human burials at this important site and provides a new picture of Homo sapiens adapting to deteriorating climate in the world's driest inhabited continent.

The epidemiology of childhood cardiomyopathy in Australia.

Abstract: Background The incidence and age distribution of primary cardiomyopathy in children are not well defined. We undertook a population-based, retrospective cohort study in Australia to document the epidemiology of childhood cardiomyopathy. Methods We analyzed all cases of primary cardiomyopathy in children who presented between 1987 and 1996 and who were younger than 10 years of age. Children were recruited from multiple sources, and cases of cardiomyopathy were classified according to World Health Organization guidelines. Results Over the 10-year period, 314 new cases of primary cardiomyopathy were identified, for an annual incidence of 1.24 per 100,000 children younger than 10 years of age (95 percent confidence interval, 1.11 to 1.38). Dilated cardiomyopathy made up 58.6 percent of cases, hypertrophic cardiomyopathy 25.5 percent, restrictive cardiomyopathy 2.5 percent, and left ventricular noncompaction 9.2 percent of cases. The incidence of all types of cardiomyopathy except restrictive declined rapidly ...

Argumentation-based negotiation

Abstract: Negotiation is essential in settings where autonomous agents have conflicting interests and a desire to cooperate. For this reason, mechanisms in which agents exchange potential agreements according to various rules of interaction have become very popular in recent years as evident, for example, in the auction and mechanism design community. However, a growing body of research is now emerging which points out limitations in such mechanisms and advocates the idea that agents can increase the likelihood and quality of an agreement by exchanging arguments which influence each others' states. This community further argues that argument exchange is sometimes essential when various assumptions about agent rationality cannot be satisfied. To this end, in this article, we identify the main research motivations and ambitions behind work in the field. We then provide a conceptual framework through which we outline the core elements and features required by agents engaged in argumentation-based negotiation, as well as the environment that hosts these agents. For each of these elements, we survey and evaluate existing proposed techniques in the literature and highlight the major challenges that need to be addressed if argument-based negotiation research is to reach its full potential.

Epidermal Viral Immunity Induced by CD8α+ Dendritic Cells But Not by Langerhans Cells

Abstract: The classical paradigm for dendritic cell function derives from the study of Langerhans cells, which predominate within skin epidermis. After an encounter with foreign agents, Langerhans cells are thought to migrate to draining lymph nodes, where they initiate T cell priming. Contrary to this, we show here that infection of murine epidermis by herpes simplex virus did not result in the priming of virus-specific cytotoxic T lymphocytes by Langerhans cells. Rather, the priming response required a distinct CD8α + dendritic cell subset. Thus, the traditional view of Langerhans cells in epidermal immunity needs to be revisited to accommodate a requirement for other dendritic cells in this response.

Compactness results in Symplectic Field Theory

Abstract: This is one in a series of papers devoted to the foundations of Symplectic Field Theory sketched in (4). We prove compactness results for moduli spaces of holomorphic curves arising in Symplectic Field Theory. The theorems generalize Gromov's compactness theorem in (8) as well as compactness theorems in Floer homology theory, (6, 7), and in contact geometry, (9, 19).

International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification. XXXVIII. Update on Terms and Symbols in Quantitative Pharmacology

Abstract: The recommendations that follow have been updated from the proposals of a Technical Subcommittee set up by the International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification (Jenkinson DH, Barnard EA, Hoyer D, Humphrey PPA, Leff P, and Shankley NP (1995) International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification. IX. Recommendations on terms and symbols in quantitative pharmacology. Pharmacol Rev 47:255-266).

Physiotherapy interventions for shoulder pain

Abstract: Background The prevalence of shoulder disorders has been reported to range from seven to 36% of the population (Lundberg 1969) accounting for 1.2% of all General Practitioner encounters in Australia (Bridges Webb 1992). Substantial disability and significant morbidity can result from shoulder disorders. While many treatments have been employed in the treatment of shoulder disorders, few have been proven in randomised controlled trials. Physiotherapy is often the first line of management for shoulder pain and to date its efficacy has not been established. This review is one in a series of reviews of varying interventions for shoulder disorders, updated from an earlier Cochrane review of all interventions for shoulder disorder. Objectives To determine the efficacy of physiotherapy interventions for disorders resulting in pain, stiffness and/or disability of the shoulder. Search methods MEDLINE, EMBASE, the Cochrane Clinical Trials Regiter and CINAHL were searched 1966 to June 2002. The Cochrane Musculoskeletal Review Group's search strategy was used and key words gained from previous reviews and all relevant articles were used as text terms in the search. Selection criteria Each identified study was assessed for possible inclusion by two independent reviewers. The determinants for inclusion were that the trial be of an intervention generally delivered by a physiotherapist, that treatment allocation was randomised; and that the study population be suffering from a shoulder disorder, excluding trauma and systemic inflammatory diseases such as rheumatoid arthritis. Data collection and analysis The methodological quality of the included trials was assessed by two independent reviewers according to a list of predetermined criteria, which were based on the PEDro scale specifically designed for the assessment of validity of trials of physiotherapy interventions. Outcome data was extracted and entered into Revman 4.1. Means and standard deviations for continuous outcomes and number of events for binary outcomes were extracted where available from the published reports. All standard errors of the mean were converted to standard deviation. For trials where the required data was not reported or not able to be calculated, further details were requested from first authors. If no further details were provided, the trial was included in the review and fully described, but not included in the meta-analysis. Results were presented for each diagnostic sub group (rotator cuff disease, adhesive capsulitis, anterior instability etc) and, where possible, combined in meta-analysis to give a treatment effect across all trials. Main results Twenty six trials met inclusion criteria. Methodological quality was variable and trial populations were generally small (median sample size = 48, range 14 to 180). Exercise was demonstrated to be effective in terms of short term recovery in rotator cuff disease (RR 7.74 (1.97, 30.32), and longer term benefit with respect to function (RR 2.45 (1.24, 4.86). Combining mobilisation with exercise resulted in additional benefit when compared to exercise alone for rotator cuff disease. Laser therapy was demonstrated to be more effective than placebo for adhesive capsulitis (RR 8, 95%CI 2.11 to 30.34) but not for supraspinatus tendinitis (RR 2, 95%CI 0.98 to 4.09). Both ultrasound and pulsed electromagnetic field therapy resulted in improvement compared to placebo in pain in calcific tendinitis (RR 1.81 (1.26, 2.60) and RR 19 (1.16, 12.43) respectively). There is no evidence of the effect of ultrasound in shoulder pain (mixed diagnosis), adhesive capsulitis or rotator cuff tendinitis. When compared to exercises, ultrasound is of no additional benefit over and above exercise alone. There is some evidence that for rotator cuff disease, corticosteroid injections are superior to physiotherapy and no evidence that physiotherapy alone is of benefit for adhesive capsulitis Authors' conclusions The small sample sizes, variable methodological quality and heterogeneity in terms of population studied, physiotherapy intervention employed and length of follow up of randomised controlled trials of physiotherapy interventions results in little overall evidence to guide treatment. There is evidence to support the use of some interventions in specific and circumscribed cases. There is a need for trials of physiotherapy interventions for specific clinical conditions associated with shoulder pain, for shoulder pain where combinations of physiotherapy interventions, as well as, physiotherapy interventions as an adjunct to other, non physiotherapy interventions are compared. This is more reflective of current clinical practice. Trials should be adequately powered and address key methodological criteria such as allocation concealment and blinding of outcome assessor.

Security and climate change

Abstract: Despite it being the most studied and arguably most profound of global environmental change problems, there is relatively little research that explores climate change as a security issue. This paper systematically explores the range of possible connections between climate change and security, including national security considerations, human security concerns, military roles, and a discussion of the widely held assumption that climate change may trigger violent conflict. The paper explains the ways in which climate change is a security issue. It includes in its discussion issues to do with both mitigation and adaptation of climate change.

Laboratory Cultivation of Widespread and Previously Uncultured Soil Bacteria

Abstract: Most soil bacteria belong to family-level phylogenetic groups with few or no known cultivated representatives. We cultured a collection of 350 isolates from soil by using simple solid media in petri dishes. These isolates were assigned to 60 family-level groupings in nine bacterial phyla on the basis of a comparative analysis of their 16S rRNA genes. Ninety-three (27%) of the isolates belonged to 20 as-yet-unnamed family-level groupings, many from poorly studied bacterial classes and phyla. They included members of subdivisions 1, 2, 3, and 4 of the phylum Acidobacteria, subdivision 3 of the phylum Verrucomicrobia, subdivision 1 of the phylum Gemmatimonadetes, and subclasses Acidimicrobidae and Rubrobacteridae of the phylum Actinobacteria. In addition, members of 10 new family-level groupings of subclass Actinobacteridae of the phylum Actinobacteria and classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria of the phylum Proteobacteria were obtained. The high degree of phylogenetic novelty and the number of isolates affiliated with so-called unculturable groups show that simple cultivation methods can still be developed further to obtain laboratory cultures of many phylogenetically novel soil bacteria.

"Stress" and coronary heart disease: psychosocial risk factors.

Abstract: An Expert Working Group of the National Heart Foundation of Australia undertook a review of systematic reviews of the evidence relating to major psychosocial risk factors to assess whether there are independent associations between any of the factors and the development and progression of coronary heart disease (CHD), or the occurrence of acute cardiac events. The expert group concluded that (i) there is strong and consistent evidence of an independent causal association between depression, social isolation and lack of quality social support and the causes and prognosis of CHD; and (ii) there is no strong or consistent evidence for a causal association between chronic life events, work-related stressors (job control, demands and strain), Type A behaviour patterns, hostility, anxiety disorders or panic disorders and CHD. The increased risk contributed by these psychosocial factors is of similar order to the more conventional CHD risk factors such as smoking, dyslipidaemia and hypertension. The identified psychosocial risk factors should be taken into account during individual CHD risk assessment and management, and have implications for public health policy and research.

Demand for Sport

Abstract: This article reviews international literature on the demand for professional sport. The first part presents a conceptual framework for understanding the sources and determinants of the demand for professional sporting contests. The second part reviews empirical evidence on key determinants of attendance at sporting events, and on other sources of demand, such as broadcasting, sponsorship, and merchandising. The review concludes that there is still much to be learned about demand for professional sport, and that there are no simple lessons to be drawn from existing literature. But important messages do emerge from studies of demand for attendance with regard to effects of uncertainty of outcome, quality of contest, and quality of viewing. © 2003 Oxford University Press and the Oxford Review of Economic Policy Limited.