Measurement of the Crab nebula polarization at 90 GHz as a calibrator for CMB experiments

CMB experiments aiming at a precise measurement of the CMB polarization, such as the Planck satellite, need a strong polarized absolute calibrator on the sky to accurately set the detectors polarization angle and the cross-polarization leakage. As the most intense polarized source in the microwave sky at angular scales of few arcminutes, the Crab nebula will be used for this purpose. Our goal was to measure the Crab nebula polarization characteristics at 90 GHz with unprecedented precision. The observations were carried out with the IRAM 30m telescope employing the correlation polarimeter XPOL and using two orthogonally polarized receivers. We processed the Stokes I, Q, and U maps from our observations in order to compute the polarization angle and linear polarization fraction. The first is almost constant in the region of maximum emission in polarization with a mean value of alpha_Sky=152.1+/-0.3 deg in equatorial coordinates, and the second is found to reach a maximum of Pi=30% for the most polarized pixels. We find that a CMB experiment having a 5 arcmin circular beam will see a mean polarization angle of alpha_Sky=149.9+/-0.2 deg and a mean polarization fraction of Pi=8.8+/-0.2%.Comment: Accepted for publication in A&A, 9 pages, 4 figure

Who has a repeat abortion? Identifying women at risk of repeated terminations of pregnancy : analysis of routinely collected health care data

Authors’ thanks goes to Mr Peter Szchechina and Mr Alastair Soutar for extracting the data for this study and to Prof Allan Templeton for initiating the TOPS database in Grampian and for critically evaluating the manuscript.Peer reviewedPostprin

Perfectionism and training distress in junior athletes: A longitudinal investigation

Perfectionistic athletes may train harder and for longer than non-perfectionistic athletes, leaving them susceptible to elevated levels of training distress. So far, however, no study has investigated the relationships between perfectionism and training distress, a key indicator of overtraining syndrome. Furthermore, no study has determined psychological predictors of overtraining syndrome. Using a two-wave design, the present study examined perfectionistic strivings, perfectionistic concerns, and training distress in 141 junior athletes (mean age 17.3 years, range 16-19 years) over 3 months of active training. Multiple regression analyses were employed to test cross-sectional and longitudinal relationships between perfectionism and training distress. In all analyses, perfectionism emerged as a significant predictor, but strivings and concerns showed differential relationships. When the cross-sectional relationships were regarded, perfectionistic concerns positively predicted training distress (p .05). The findings suggest that sports scientists who wish to identify athletes at risk of overtraining syndrome may monitor athletes’ perfectionistic concerns as a possible risk factor

Cannabis use and disorder transitions among a mixed community sample of at-risk adolescents and adults: A prospective New Zealand study

Introduction and Aims: The trajectories of cannabis use disorder (CUD) require more comprehensive delineation to expedite recognition of incubating dependence among high-risk users. This study examined baseline cannabis use and CUD over 12 months using DSM-IV/ICD10 diagnoses to distinguish transition groups. Design and Methods: In a prospective naturalistic design, 194 heterogeneous cannabis users (128 adolescents, 66 adults) aged 13-61 years were voluntarily recruited and assessed at baseline, and then re-assessed 12-months later. Results: Most participants met criteria for a baseline CUD (70% dependence, 20% abuse), 12 adolescents were 'diagnostic orphans', and 5 symptom-free. At follow-up, 25% adolescents reported using less, 6% the same level, and 69% using more cannabis. Significantly increased symptoms and dependence severity were reported, with no adolescent/adult differences evident. Three diagnostic transition groups were identified. While 84% adolescents (n=108) remained stable, 5% (n=7) had improved, 10% (n=13) had deteriorated. ‘Deteriorators’ scored significantly higher than ‘improvers’ on cannabis use, symptoms, and dependence severity measures. A subjective loss of control over cannabis use was among the earliest DSM-IV features among younger users on a trajectory towards dependence. Most participants (79%) anticipated difficulty trying to reduce/quit their use. Discussion and Conclusions: Younger adolescents can rapidly develop cannabis dependence, reporting similar and equally severe symptoms as longer-term adult users. Impaired control over use occurs early in trajectories towards dependence. The seeming intractability of problematic cannabis use calls for concerted cannabis screening and early intervention (SEI) efforts at an earlier age to avert or reduce harmful consequences of cannabis use in the community.falsefals

Comparison of T1 mapping techniques for ECV quantification. histological validation and reproducibility of ShMOLLI versus multibreath-hold T1 quantification equilibrium contrast CMR

BACKGROUND: Myocardial extracellular volume (ECV) is elevated in fibrosis or infiltration and can be quantified by measuring the haematocrit with pre and post contrast T1 at sufficient contrast equilibrium. Equilibrium CMR (EQ-CMR), using a bolus-infusion protocol, has been shown to provide robust measurements of ECV using a multibreath-hold T1 pulse sequence. Newer, faster sequences for T1 mapping promise whole heart coverage and improved clinical utility, but have not been validated. METHODS: Multibreathhold T1 quantification with heart rate correction and single breath-hold T1 mapping using Shortened Modified Look-Locker Inversion recovery (ShMOLLI) were used in equilibrium contrast CMR to generate ECV values and compared in 3 ways.Firstly, both techniques were compared in a spectrum of disease with variable ECV expansion (n=100, 50 healthy volunteers, 12 patients with hypertrophic cardiomyopathy, 18 with severe aortic stenosis, 20 with amyloid). Secondly, both techniques were correlated to human histological collagen volume fraction (CVF%, n=18, severe aortic stenosis biopsies). Thirdly, an assessment of test:retest reproducibility of the 2 CMR techniques was performed 1 week apart in individuals with widely different ECVs (n=10 healthy volunteers, n=7 amyloid patients). RESULTS: More patients were able to perform ShMOLLI than the multibreath-hold technique (6% unable to breath-hold). ECV calculated by multibreath-hold T1 and ShMOLLI showed strong correlation (r(2)=0.892), little bias (bias -2.2%, 95%CI -8.9% to 4.6%) and good agreement (ICC 0.922, range 0.802 to 0.961, p<0.0001). ECV correlated with histological CVF% by multibreath-hold ECV (r(2)= 0.589) but better by ShMOLLI ECV (r(2)= 0.685). Inter-study reproducibility demonstrated that ShMOLLI ECV trended towards greater reproducibility than the multibreath-hold ECV, although this did not reach statistical significance (95%CI -4.9% to 5.4% versus 95%CI -6.4% to 7.3% respectively, p=0.21). CONCLUSIONS: ECV quantification by single breath-hold ShMOLLI T1 mapping can measure ECV by EQ-CMR across the spectrum of interstitial expansion. It is procedurally better tolerated, slightly more reproducible and better correlates with histology compared to the older multibreath-hold FLASH techniques

A short empirical note on perfectionism and flourishing

Flourishing describes an optimal state of mental health characterized by emotional, psychological, and social well-being. In a recent publication, Flett and Hewitt (2015) suggested that perfectionism prevents people from flourishing. Perfectionism, however, is a multidimensional personality characteristic, and its various dimensions show different relationships with indicators of subjective well-being. In the first empirical study of perfectionism and flourishing, we examined the relationships of multidimensional perfectionism (self-oriented, other-oriented, and socially prescribed perfectionism) and self-reported flourishing in the past two weeks. Results from the sample of 388 university students revealed that only socially prescribed perfectionism showed a negative relationship with flourishing, whereas self-oriented perfectionism showed a positive relationship. These results were unchanged when positive and negative affect were controlled statistically. Our findings indicate that not all dimensions of perfectionism undermine flourishing and that it is important to differentiate perfectionistic strivings and concerns when regarding the perfectionism–flourishing relationship

Exclusive J/ψJ/\psi production in ultraperipheral Pb+Pb collisions to NLO pQCD

We present the first NLO pQCD study of coherent exclusive $J/\psi$ photoproduction in ultraperipheral heavy-ion collisions (UPCs) at the LHC. Taking the generalized parton distributions (GPDs) in their forward limit, as parton distribution functions (PDFs), we quantify the NLO contributions in the rapidity-differential cross section, show that the real part of the amplitude must not be neglected, study the gluon and quark contributions, chart the scale-choice and PDF uncertainties, and compare the NLO results with LHC and HERA data. We show that the scale dependence is significant but a scale choice can be found with which we reproduce the 2.76 and 5.02 TeV UPC data. In particular, we show that the process is clearly more sensitive to the nuclear quark PDFs than thought before.Comment: 5 pages, 5 figures, contributed talk by T.L. at the XXIX International Conference on Ultra-relativistic Nucleus-Nucleus Collisions, Quark Matter 2022, 4-10 April, 2022, Krakow, Polan

Exclusive quarkonium photoproduction in AA+AA UPCs at the LHC in NLO pQCD

We present the first study of coherent exclusive quarkonium ($J/\psi$, $\Upsilon$) photoproduction in ultraperipheral nucleus-nucleus collisions (UPCs) at the LHC in the framework of collinear factorization and next-to-leading order (NLO) perturbative QCD (pQCD). We make NLO predictions for the $J/\psi$ and $\Upsilon$ rapidity distributions for lead (Pb) and oxygen (O) beams, and quantify their dependence on the factorization/renormalization scale, nuclear parton distribution functions (PDFs) and their uncertainties, and on differences between nuclear PDFs and generalized parton distribution functions (GPDs). We show that within the PDF-originating uncertainties our approach provides a good description of the available $J/\psi$ photoproduction data in Pb+Pb UPCs at the LHC but that the scale uncertainty is significant. We demonstrate that at NLO pQCD the quark contributions are important in the $J/\psi$ case but that gluons clearly dominate the $\Upsilon$ cross sections. We also study how the scale dependence could be tamed by considering O+O/Pb+Pb ratios of the exclusive $J/\psi$ UPC cross sections, and how HERA and p+p/Pb LHC data can help in obtaining better-controlled NLO predictions in the $\Upsilon$ case.Comment: 6 pages, 5 figures, contributed talk by K.J.E. at the 11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, Hard Probes 2023, 26-31 March 2023, Aschaffenburg, German

Systematic review of the clinical effectiveness and cost-effectiveness of rapid point-of-care tests for the detection of genital chlamydia infection in women and men.

Peer reviewedPublisher PD

Assessing the risks associated with internal erosion phenomena in aging embankment dams: a New Zealand perspective

Earth embankment dams form a vital part of New Zealand’s hydropower, agricultural, and water supply infrastructure. The challenges faced in the management of aging embankment dams are compounded by factors specific to New Zealand, including large variability in soil types and the highly tectonic environment in which the dams are located. Internal erosion, triggered by both seismic and non-seismic events, is considered one of the primary risks to New Zealand embankment dams. Spurred by the recent Canterbury Earthquake Sequence, hydropower asset owners in New Zealand have expressed a need for improved guidance for the evaluation of embankments (1) following significant earthquake ground motions, and (2) from a whole-life perspective. This study considers the applicability of existing empirical methods to assess the potential for internal erosion in the New Zealand context. Two distinct mechanisms of internal erosion are considered: (1) internal instability, and (2) filter incompatibility. Four existing empirical geometric methods were used to assess the potential for internal instability in 19 widely-graded New Zealand soils. One existing method was found to be mathematically ineffectual with respect to the widely-graded soils considered in this study and all methods lack reliable verification using volcanic soils. Existing screening methods suggest that a number of glacial, alluvial, and volcanic materials used in construction of New Zealand’s large earth dams may be susceptible to some degree of internal instability phenomena, irrespective of seismic hazard. Secondly, a case-study concerning a common type of widely-graded base-filter soil interface demonstrates ambiguous analysis results arising from overlap in No Erosion and Excessive Erosion thresholds. Uncertainties in interpretation could be resolved by the future development of statistical guidelines for filter assessment. With regard to both internal instability and filter incompatibility mechanisms, the applicability of existing empirical analysis techniques to New Zealand soils appears limited due to a lack verification for the diverse geological range of fill soils encountered. In addition, existing stability thresholds have not been verified for long-term or seismic loading conditions inherent in the New Zealand context. This study highlights significant shortcomings in the applicability of existing screening methods used to assess the potential for internal erosion in New Zealand soils