The association between school performance at 14 years and young adults' use of cannabis: An Australian birth cohort study

This study examines, firstly, the association between school performance at 14 years and frequency of use of cannabis in early adulthood and, secondly, whether this association is explained by family and individual characteristics, including child cognitive capacity in childhood and adolescence. Data are from a cohort of 3,478 Australian young adults who were followed up from birth to age 21 years. Data on child school performance and use of cannabis were collected at the 14- and 21-year follow-ups, respectively. Child school performance was assessed at 14 years via self- and maternal-report. Potential confounding factors were measured between the child's birth and age 14 years. School performance at 14 years predicts young adults' use of cannabis. Children who had lower school performance had increased risk of frequent use of cannabis in young adulthood. Exploration of the pathway linking school performance and cannabis use in young people may help identify opportunities for preventive interventions

Systematic review of economic evaluations and cost analyses of guideline implementation strategies

Objectives To appraise the quality of economic studies undertaken as part of evaluations of guideline implementation strategies; determine their resources use; and recommend methods to improve future studies. Methods Systematic review of economic studies undertaken alongside robust study designs of clinical guideline implementation strategies published (1966-1998). Studies assessed against the BMJ economic evaluations guidelines for each stage of the guideline process (guideline development, implementation and treatment). Results 235 studies were identified, 63 reported some information on cost. Only 3 studies provided evidence that their guideline was effective and efficient. 38 reported the treatment costs only, 12 implementation and treatment costs, 11 implementation costs alone, and two guideline development, implementation and treatment costs. No study gave reasonably complete information on costs. Conclusions Very few satisfactory economic evaluations of guideline implementation strategies have been performed. Current evaluations have numerous methodological defects and rarely consider all relevant costs and benefits. Future evaluations should focus on evaluating the implementation of evidence based guidelines. Keywords: Cost-effectiveness analysis, physician (or health care professional) behaviour, practice guidelines, quality improvement, systematic review.Peer reviewedAuthor versio

Large slow-roll corrections to the bispectrum of noncanonical inflation

Nongaussian statistics are a powerful discriminant between inflationary models, particularly those with noncanonical kinetic terms. Focusing on theories where the Lagrangian is an arbitrary Lorentz-invariant function of a scalar field and its first derivatives, we review and extend the calculation of the observable three-point function. We compute the "next-order" slow-roll corrections to the bispectrum in closed form, and obtain quantitative estimates of their magnitude in DBI and power-law k-inflation. In the DBI case our results enable us to estimate corrections from the shape of the potential and the warp factor: these can be of order several tens of percent. We track the possible sources of large logarithms which can spoil ordinary perturbation theory, and use them to obtain a general formula for the scale dependence of the bispectrum. Our result satisfies the next-order version of Maldacena's consistency condition and an equivalent consistency condition for the scale dependence. We identify a new bispectrum shape available at next-order, which is similar to a shape encountered in Galileon models. If fNL is sufficiently large this shape may be independently detectable.Comment: v1: 37 pages, plus tables, figures and appendices. v2: supersedes version published in JCAP; some clarifications and more detailed comparison with earlier literature. All results unchanged. v3:improvements to some plots; text unchange

Beauty is Distractive: Particle production during multifield inflation

We consider a two-dimensional model of inflation, where the inflationary trajectory is "deformed" by a grazing encounter with an Extra Species/Symmetry Point (ESP) after the observable cosmological scales have left the Hubble radius. The encounter entails a sudden production of particles, whose backreaction causes a bending of the trajectory and a temporary decrease in speed, both of which are sensitive to initial conditions. This "modulated" effect leads to an additional contribution to the curvature perturbation, which can be dominant if the encounter is close. We compute associated non-Gaussianities, the bispectrum and its scale dependence as well as the trispectrum, which are potentially detectable in many cases. In addition, we consider a direct modulation of the coupling to the light field at the ESP via a modulaton field, a mixed scenario whereby the modulaton is identified with a second inflaton, and an extended Extra Species Locus (ESL); all of these scenarios lead to similar additional contributions to observables. We conclude that inflaton interactions throughout inflation are strongly constrained if primordial non-Gaussianities remain unobserved in current experiments such as PLANCK. If they are observed, an ESP encounter leaves additional signatures on smaller scales which may be used to identify the model.Comment: 41 pages, 6 figures; v2: references and minor clarifications added, conclusions unchange

The age and hydrological history of Blue Lake, South Australia

Three sediment cores from the Blue Lake, a groundwater fed lake of volcanic origin in South Australia, have been investigated using a range of chemical and isotopic parameters. The C-14 activity of both the inorganic and organic carbon fractions of the sediment decreases monotonically with depth. The rate of change with depth is greater for near-surface samples with an apparent hiatus in sedimentation rate at about 7000 yr B.P. Estimates of age for the precipitated authigenic carbonate, after correction for dilution with dead carbon from the groundwater, agree well with calculated ages from the organic carbon fraction of the sediment. We suggest the lake is much older than previously proposed using other dating techniques. Variations in the delta(13)C and delta(18)O composition of the authigenic carbonate reflect different residence times of dissolved inorganic carbon and water in the lake caused by changes in the lake level. During periods of hydrologic steady-state, it is suggested that relative changes in the temperature of the lake can be seen in delta(18)O changes in authigenic carbonate. Blue Lake has been undergoing sedimentation for at least 28,000 years, including two lengthy periods of hydrologic steady state. The lake, for a large proportion of its existence, was much shallower while for the last 7000 years has maintained a level close to the present one. The influence of pumping from the lake for urban water supply during this century is reflected in the isotopic composition of carbonate in the sediment

Collaborative meta-analysis finds no evidence of a strong interaction between stress and 5-HTTLPR genotype contributing to the development of depression

The hypothesis that the S allele of the 5-HTTLPR serotonin transporter promoter region is associated with increased risk of depression, but only in individuals exposed to stressful situations, has generated much interest, research, and controversy since first proposed in 2003. Multiple meta-analyses combining results from heterogeneous analyses have not settled the issue. To determine the magnitude of the interaction and the conditions under which it might be observed, we performed new analyses on 31 datasets containing 38 802 European-ancestry subjects genotyped for 5-HTTLPR and assessed for depression and childhood maltreatment or other stressful life events, and meta-analyzed the results. Analyses targeted two stressors (narrow, broad) and two depression outcomes (current, lifetime). All groups that published on this topic prior to the initiation of our study and met the assessment and sample size criteria were invited to participate. Additional groups, identified by consortium members or self-identified in response to our protocol (published prior to the start of analysis1) with qualifying unpublished data were also invited to participate. A uniform data analysis script implementing the protocol was executed by each of the consortium members. Our findings do not support the interaction hypothesis. We found no subgroups or variable definitions for which an interaction between stress and 5-HTTLPR genotype was statistically significant. In contrast, our findings for the main effects of life stressors (strong risk factor) and 5-HTTLPR genotype (no impact on risk) are strikingly consistent across our contributing studies, the original study reporting the interaction, and subsequent meta-analyses. Our conclusion is that if an interaction exists in which the S allele of 5-HTTLPR increases risk of depression only in stressed individuals, then it is not broadly generalizable, but must be of modest effect size and only observable in limited situations

Track D Social Science, Human Rights and Political Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd