The oral medicine of tooth wear

This review illustrates, through a series of case histories, how oral medicine insights aid the diagnosis and management of patients with excessive tooth wear. The cases reviewed are drawn from the records of 500 southeast Queensland patients referred to the author over a 12 year period. Patients most at risk of dental erosion have work and sports dehydration, caffeine addiction, gastro-oesophageal reflux, asthma, diabetes mellitus, hypertension or other systemic diseases or syndromes that predispose to xerostomia. Saliva protects the teeth from the extrinsic and intrinsic acids which cause dental erosion. Erosion, exacerbated by attrition and abrasion, is the main cause of tooth wear. These cases illustrate that teeth, oral mucosa, salivary glands, skin and eyes should be examined for evidence of salivary hypofunction and attendant medical conditions. Based on comprehensive oral medicine, dietary analyses and advice, it would seem patients need self-management plans to deal with incipient chronic tooth wear. The alternative is the expensive treatment of pain, occlusal damage and pulp death required to repair the effects of acute severe tooth wear.

Predicting sheetwash and rill erosion over the Australian continent

Soil erosion is a major environmental issue in Australia. It reduces land productivity and has off-site effects of decreased water quality. Broad-scale spatially distributed soil erosion estimation is essential for prioritising erosion control programs and as a component of broader assessments of natural resource condition. This paper describes spatial modelling methods and results that predict sheetwash and rill erosion over the Australian continent using the revised universal soil loss equation (RUSLE) and spatial data layers for each of the contributing environmental factors. The RUSLE has been used before in this way but here we advance the quality of estimation. We use time series of remote sensing imagery and daily rainfall to incorporate the effects of seasonally varying cover and rainfall intensity, and use new digital maps of soil and terrain properties. The results are compared with a compilation of Australian erosion plot data, revealing an acceptable consistency between predictions and observations. The modelling results show that: (1) the northern part of Australia has greater erosion potential than the south; (2) erosion potential differs significantly between summer and winter; (3) the average erosion rate is 4.1 t/ha. year over the continent and about 2.9 x 10(9) tonnes of soil is moved annually which represents 3.9% of global soil erosion from 5% of world land area; and (4) the erosion rate has increased from 4 to 33 times on average for agricultural lands compared with most natural vegetated lands.

The psychological symptoms of conjugal bereavement in elderly men over the first 13 months

Objective. The purpose of this study was to investigate the psychological symptoms experienced by recently widowed older men. It was hypothesized that conjugal bereavement in this group would be characterized by a mixture of depression, anxiety and loneliness. Design. Double cohort study. Setting. Suburban community population of Brisbane, Australia. Participants. Consecutive widowers (65+ years; N = 57) identified from official death records. Married men (65+ years; N = 57) identified from the electoral roll. Widowers interviewed at 6 weeks, 6 months and 13 months post-bereavement. Married men interviewed at similar intervals. Measures. Bereavement Phenomenology Questionnaire (BPQ), a 22-item self-report measure employing a four-point response scale to rate the frequency of phenomena over the previous fortnight. Zung Self-rating Depression Scale (SDS). State component of the Spielberger State/Trait Anxiety Inventory (STAI). Revised UCLA Loneliness Scale (ULS). 28-item General Health Questionnaire (GHQ). Results. Widowers reported more state anxiety and general psychological distress, but not more depression or loneliness, than matched married men over the first 13 months post-bereavement. Widowers also reported more sleep disturbance and thoughts of death and suicide than married men. Level of state anxiety was strongly correlated with intensity of grief, but not with age, income, education, occupational prestige, cognitive function, duration of wife's final illness or expectedness of wife's death. Conclusions. The main hypothesis was not supported, as anxiety symptoms were the predominant clinical feature of recent conjugal bereavement among older men. The nature of these anxiety symptoms requires further investigation in recently widowed older persons.

Handing over the keys : Contingency, power and resistance in the context of section 3LA of the Australian Crimes Act 1914

Using the work and ideas of French theorist Michel Foucault the writer examines s 3LA of the Crimes Act, which provides law enforcement officers with power to compel a person to reveal their private encryption keys and other personal information, and concludes that such a section creates fear, redirects flow of power between law enforcement agencies and citizens, and creates resistance.

Quantum computing and polynomial equations over the finite field Z(2)

What is the computational power of a quantum computer? We show that determining the output of a quantum computation is equivalent to counting the number of solutions to an easily computed set of polynomials defined over the finite field Z(2). This connection allows simple proofs to be given for two known relationships between quantum and classical complexity classes, namely BQP subset of P-#P and BQP subset of PP.

Changes in use of disease-modifying anti-rheumatic drugs in Australia over the period 1992-2004

Purpose Evidence is growing that early use of disease-modifying anti-rheumatic drugs (DMARDs) and combinations of these drugs provide optimal care for people with rheumatoid arthirits. The aim of this study was to describe objectively the pattern of consumption of DMARDs in the Australian community (community-based prescribing, specialist and general practitioner) 1992-2004, and to compare this with prescribing patterns reported in other countries. Method Dispensing statistics from the Pharmaceutical Benefit Scheme (PBS-Australia's universal prescription subsidy scheme) were analysed and temporal trends evaluated. Drug consumption was calculated as the number of dispensed defined daily doses (DDD)/1000 inhabitants/day (WHO ATC/DDD classification 2005). Results The consumption of DMARDs in the Australian community increased steadily from 2.6 DDD/1000 inhabitants/ day in 1992 to 5.5 DDD/1000 inhabitants/day. Over the period 1992-2004, methotrexate (MTX) was the most commonly used DMARD (from 0.6 to 3.0 DDD/1000 inhabitants/day). Consumption of gold (parentcral and oral) and penicillamine declined during this time. The inclusion of leflunomide on the PBS in 2000 contributed to the increase in DMARD usage. Conclusion Use of DMARDs within the Australian community has increased in recent years, coinciding with the change in guidelines for therapy for rheumatoid arthritis (RA) to earlier use of DMARDs and the more common use of combinations. This study used DDD methodology to quantify trends for DMARD consumption and these trends are broadly consistent with international prescribing patterns assessed using different methodologies. Copyright (c) 2006 John Wiley & Sons, Ltd.

Geochemical changes recorded in Lynch's Crater, Northeastern Australia, over the past 50 ka

There are many geochemical reconstructions of environmental change in the mid and high latitudes but relatively few in the tropical latitudes, despite their considerable potential for reconstructing environmental processes that cannot be identified using more traditional proxies. Here we present one reconstruction of environmental change for the tropics. This reconstruction covers the past 50 ka using a suite of geochemical data from the high-resolution sequence of Lynch's Crater in northeast Queensland, Australia, a region highly sensitive to El Nino-Southern Oscillation (ENSO) activity. The 23 major oxides and trace elements measured Could be summarised by extracting three axes using principal components analysis (accounting for 72% of the variability). The data indicate that the greatest variability in the geochemical data accounted for erosional activity within the catchment that was associated with past changes in the frequency of ENSO activity (though this was less sensitive during wetter periods, probably as a result of buffering by high vegetation cover). The remaining variability was largely explained by elements that form complexes with organic compounds (e.g., humic acids) and those that are important nutrients for specific vegetation types (and therefore a measure of vegetation distribution). For more detailed reconstructions, further work is required to disentangle the complex controls of clements within sedimentary sequences. (c) 2005 Elsevier B.V. All rights reserved.

Modelling sediment delivery ratio over the Murray Darling Basin

This paper presents a scientific and technical description of the modelling framework and the main results of modelling the long-term average sediment delivery at hillslope to medium-scale catchments over the entire Murray Darling Basin (MDB). A theoretical development that relates long-term averaged sediment delivery to the statistics of rainfall and catchment parameters is presented. The derived flood frequency approach was adapted to investigate the problem of regionalization of the sediment delivery ratio (SDR) across the Basin. SDR, a measure of catchment response to the upland erosion rate, was modeled by two lumped linear stores arranged in series: hillslope transport to the nearest streams and flow routing in the channel network. The theory shows that the ratio of catchment sediment residence time (SRT) to average effective rainfall duration is the most important control in the sediment delivery processes. In this study, catchment SRTs were estimated using travel time for overland flow multiplied by an enlargement factor which is a function of particle size. Rainfall intensity and effective duration statistics were regionalized by using long-term measurements from 195 pluviograph sites within and around the Basin. Finally, the model was implemented across the MDB by using spatially distributed soil, vegetation, topographical and land use properties under Geographic Information System (GIs) environment. The results predict strong variations in SDR from close to 0 in floodplains to 70% in the eastern uplands of the Basin. (c) 2005 Elsevier Ltd. All rights reserved.