265 research outputs found

    Solutions to the reconstruction problem in asymptotic safety

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    Starting from a full renormalised trajectory for the effective average action (a.k.a. infrared cutoff Legendre effective action) Γk\Gamma_k, we explicitly reconstruct corresponding bare actions, formulated in one of two ways. The first step is to construct the corresponding Wilsonian effective action SkS^k through a tree-level expansion in terms of the vertices provided by Γk\Gamma_k. It forms a perfect bare action giving the same renormalised trajectory. A bare action with some ultraviolet cutoff scale Λ\Lambda and infrared cutoff kk necessarily produces an effective average action ΓkΛ\Gamma^\Lambda_k that depends on both cutoffs, but if the already computed SΛS^\Lambda is used, we show how ΓkΛ\Gamma^\Lambda_k can also be computed from Γk\Gamma_k by a tree-level expansion, and that ΓkΛ→Γk\Gamma^\Lambda_k\to\Gamma_k as Λ→∞\Lambda\to\infty. Along the way we show that Legendre effective actions with different UV cutoff profiles, but which correspond to the same Wilsonian effective action, are related through tree-level expansions. All these expansions follow from Legendre transform relationships that can be derived from the original one between ΓkΛ\Gamma^\Lambda_k and SkS^k.Comment: 32 page

    Fixed point structure of the conformal factor field in quantum gravity

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    The O(?2) background-independent flow equations for conformally reduced gravity are shown to be equivalent to flow equations naturally adapted to scalar field theory with a wrong-sign kinetic term. This sign change is shown to have a profound effect on the renormalization group properties, broadly resulting in a continuum of fixed points supporting both a discrete and a continuous eigenoperator spectrum, the latter always including relevant directions. The properties at the Gaussian fixed point are understood in particular depth, but also detailed studies of the local potential approximation, and the full O(?2) approximation are given. These results are related to evidence for asymptotic safety found by other authors

    Major Depression among methamphetamine users entering drug treatment programs

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    Objective: To determine the prevalence of major depression among people entering treatment for methamphetamine use. Design, setting and participants: The study was a cross-sectional survey involving 41 specialised drug and alcohol treatment agencies in Brisbane and Sydney. Services provided by these agencies included residential rehabilitation, detoxification and counselling. Participants were 400 people entering treatment for methamphetamine use who were recruited from participating treatment agencies between January 2006 and November 2007. Participants underwent a structured, face-to-face, 1.5-hour interview. Assessment instruments included the Composite International Diagnostic Interview and the Short Form 12. Main outcome measure: Diagnosis of a major depressive episode in the year prior to the study. Results: The prevalence of major depression in the year prior to the study was 40% (95% CI, 35%-44%). A noteworthy post-hoc observation was that a further 44% of participants met the symptom criteria for major depression but were excluded from a diagnosis because their symptoms were better accounted for by psychoactive substance use. Both major depression and these latter cases of "substance-induced depression" were associated with severe symptoms of depression, high levels of disability and suicidal ideation. Conclusion: Most people entering treatment programs for methamphetamine use have levels of depression that require clinical management. Making a diagnosis of major depression in the context of heavy methamphetamine use is problematic because of substance-induced symptoms of depression

    Universal cannabis outcomes from the Climate and Preventure (CAP) study : a cluster randomised controlled trial

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    Background: The Climate and Preventure (CAP) study was the first trial to assess and demonstrate the effectiveness of a combined universal and selective approach for preventing alcohol use and related harms among adolescents. The current paper reports universal effects from the CAP study on cannabis-related outcomes over three years. Methods: A cluster randomized controlled trial was conducted with 2190 students from twenty-six Australian high schools (mean age: 13.3 yrs., SD 0.48). Participants were randomised to one of four conditions; universal prevention for all students (Climate); selective prevention for high-risk students (Preventure); combined universal and selective prevention (Climate and Preventure; CAP); or health education as usual (Control). Participants were assessed at baseline, post intervention (6–9 months post baseline), and at 12-, 24- and 36-months, on measures of cannabis use, knowledge and related harms. This paper compares cannabis-related knowledge, harms and cannabis use in the Control, Climate and CAP groups as specified in the protocol, using multilevel mixed linear models to assess outcomes. Results: Compared to Control, the Climate and CAP groups showed significantly greater increases in cannabis-related knowledge initially (p < 0.001), and had higher knowledge at the 6, 12 and 24-month follow-ups. There was no significant difference between the Climate and CAP groups. While no differences were detected between Control and the CAP and Climate groups on cannabis use or cannabis-related harms, the prevalence of these outcomes was lower than anticipated, possibly limiting power to detect intervention effects. Additional Bayesian analyses exploring confidence in accepting the null hypothesis showed there was insufficient evidence to conclude that the interventions had no effect, or to conclude that they had a meaningfully large effect. Conclusions: Both the universal Climate and the combined CAP programs were effective in increasing cannabisrelated knowledge for up to 2 years. The evidence was inconclusive regarding whether the interventions reduced cannabis use and cannabis-related harms. A longer-term follow-up will ascertain whether the interventions become effective in reducing these outcomes as adolescents transition into early adulthood

    Drink driving among Aboriginal and Torres Strait Islander Australians: what has been done and where to next?

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    The Australian Government will set the direction for addressing road safety over the next decade with its 2021–2030 National Road Safety Strategy. This road map will detail objectives and goals agreed upon by all Australian states and territories. Similar to previous national strategies, Aboriginal and Torres Strait Islander (Indigenous) Australians are a high priority population. Indigenous Australians are over-represented in serious injury and fatal road crashes, with alcohol a leading factor. Therapeutic and educational programs are a major strategy among the suite of measures designed to reduce and prevent drink driving in Australia. The release of this new strategy provides a timely opportunity to reflect on what is known about drink driving among Indigenous Australians and to consider the suitability of existing therapeutic and educational drink driving programs for Indigenous Australian contexts. Here, we summarise factors that contribute to drink driving in this population and identify outstanding knowledge gaps. Then, we present an overview of drink driving programs available for Indigenous Australians along with suggestions for why tailored programs are needed to suit local contexts. The response to address drink driving among Indigenous Australians has been fragmented Australia-wide. A coordinated national response, with ongoing monitoring and evaluation, would improve policy effectiveness and inform more efficient allocation of resources. Together this information can help create suitable and effective drink driving programs for Indigenous drivers and communities Australia-wide

    The validity of the Substance Use Risk Profile Scale (SURPS) among Australian adolescents

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    Aims: This study investigated the validity of a brief personality screening measure for substance use in adolescents, the Substance Use Risk Profile Scale (SURPS), among Australian adolescents. Design and participants: A total of 527 adolescents (mean age: 13.38 years, SD=0.43) from seven Australian schools were assessed at two time points 24 months apart. The concurrent and predictive validity of the SURPS was determined using a series of linear and logistic regressions, and was compared to the results in a United Kingdom (UK) sample. SURPS subscale scores for the Australian population were also reported and compared to those in the UK. Findings: Overall, the SURPS subscale scores for Australian adolescents were similar to those for adolescents from the UK. Tests of concurrent and predictive validity in the Australian sample demonstrated that the all four personality profiles - Hopelessness (H), Anxiety Sensitivity (AS), Impulsivity (IMP), and Sensation Seeking (SS) - were related to measures of substance use and other behavioural and emotional characteristics. In addition, all the predicted specific prospective relationships between the personality profiles and particular substance use and other behavioural problems were confirmed except that H was not associated with illicit drug use. Overall, the results were similar between the Australian and UK samples. Conclusions: The SURPS is a valid and useful measure for identifying Australian adolescents at high-risk for substance use and other emotional and behavioural problems. Implications for prevention are discussed

    Short screening tools for risky drinking in Aboriginal and Torres Strait Islander Australians : Modified AUDIT-C and a new approach

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    Background Alcohol consumption among Indigenous Australians can involve a stop-start pattern of drinking, with consumption well above recommended guidelines on each occasion. Such intermittent drinking patterns can make screening for risky drinking difficult. This study evaluates the ability of several short alcohol screening tools, contained in the Grog Survey Application, to detect short- or long-term risky drinking as defined by Australian guidelines. Tested tools include a modification of Alcohol Use Disorders Identification Test-Consumption (AUDIT-Cm). Methods Alcohol consumption was assessed in current drinkers in the past year (n = 184) using AUDIT-Cm and using the last four drinking occasions (Finnish method). Sensitivity and specificity were assessed relative to the Finnish method, for how AUDIT-Cm score (3 + for women, 4 + for men), and how subsets of AUDIT-Cm questions (AUDIT-1m and AUDIT-2m; and AUDIT-3mV alone) were able to determine short- or long-term risk from drinking. Responses to AUDIT-Cm were used to calculate the average standard drinks consumed per day, and the frequency at which more than four standard drinks were consumed on single occasions. Finally, shorter versions of the Finnish method (1, 2, or 3 occasions of drinking) were compared to the full Finnish method, by examining the percentage of variance retained by shorter versions. Results AUDIT-Cm has a high sensitivity in detecting at-risk drinking compared with the Finnish method (sensitivity = 99%, specificity = 67%). The combination of AUDIT-1m and AUDIT-2m was able to classify the drinking risk status for all but four individuals in the same way as the Finnish method did. For the Finnish method, two drinking sessions to calculate drinks per drinking occasion, and four to calculate frequency resulted in nearly identical estimates to data on all four of the most recent drinking occasions (r2 = 0.997). Conclusions The combination of AUDIT-1m and AUDIT-2m may offer advantages as a short screening tool, over AUDIT-3mV, in groups where intermittent and high per occasion drinking is common. As an alternative to the full Finnish method, the quantity consumed on the last two occasions and timing of the last four occasions may provide a practical short screening tool

    Pathways to prevention: protocol for the CAP (Climate and Preventure) study to evaluate the long-term effectiveness of school-based universal, selective and combined alcohol misuse prevention into early adulthood

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    Background: Alcohol use and associated harms are among the leading causes of burden of disease among young people, highlighting the need for effective prevention. The Climate and Preventure (CAP) study was the first trial of a combined universal and selective school-based approach to preventing alcohol misuse among adolescents. Initial results indicate that universal, selective and combined prevention were all effective in delaying the uptake of alcohol use and binge drinking for up to 3 years following the interventions. However, little is known about the sustainability of prevention effects across the transition to early adulthood, a period of increased exposure to alcohol and other drug use. This paper describes the protocol for the CAP long-term follow-up study which will determine the effectiveness of universal, selective and combined alcohol misuse prevention up to 7 years post intervention, and across the transition from adolescence into early adulthood. Methods: A cluster randomized controlled trial was conducted between 2012 and 2015 with 2190 students (mean age: 13.3 yrs) from 26 Australian high schools. Participants were randomized to receive one of four conditions; universal prevention for all students (Climate); selective prevention for high-risk students (Preventure); combined universal and selective prevention (Climate and Preventure; CAP); or health education as usual (Control). The positive effect of the interventions on alcohol use at 12-, 24- and 36-month post baseline have previously been reported. This study will follow up the CAP study cohort approximately 5- and 7-years post baseline. The primary outcome will be alcohol use and related harms. Secondary outcomes will be cannabis use, alcohol and other drug harms including violent behavior, and mental health symptomatology. Analyses will be conducted using multi-level, mixed effects models within an intention-to-treat framework. Discussion: This study will provide the first ever evaluation of the long-term effectiveness of combining universal and selective approaches to alcohol prevention and will examine the durability of intervention effects into the longer-term, over a 7-year period from adolescence to early adulthood
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