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

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

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

Perfectionism, achievement motives, and attribution of success and failure in female soccer players

While some researchers have identified adaptive perfectionism as a key characteristic to achieving elite performance in sport, others see perfectionism as a maladaptive characteristic that undermines, rather than helps, athletic performance. Arguing that perfectionism in sport contains both adaptive and maladaptive facets, the present article presents a study of N 5 74 female soccer players investigating how two facets of perfectionism—perfectionistic strivings and negative reactions to imperfection (Stoeber, Otto, Pescheck, Becker, & Stoll, 2007)—are related to achievement motives and attributions of success and failure. Results show that striving for perfection was related to hope of success and self-serving attributions (internal attribution of success). Moreover, once overlap between the two facets of perfectionism was controlled for, striving for perfection was inversely related to fear of failure and self-depreciating attributions (internal attribution of failure). In contrast, negative reactions to imperfection were positively related to fear of failure and self-depreciating attributions (external attribution of success) and inversely related to self-serving attributions (internal attribution of success and external attribution of failure). It is concluded that striving for perfection in sport is associated with an adaptive pattern of positive motivational orientations and self-serving attributions of success and failure, which may help athletic performance. In contrast, negative reactions to imperfection are associated with a maladaptive pattern of negative motivational orientations and self-depreciating attributions, which is likely to undermine athletic performance. Consequently, perfectionism in sport may be adaptive in those athletes who strive for perfection, but can control their negative reactions when performance is less than perfect

Exclusive J/psi : photoproduction in ultraperipheral Pb plus Pb collisions at the CERN Large Hadron Collider calculated at next-to-leading order perturbative QCD

We present the first next-to-leading-order (NLO) perturbative QCD (pQCD) study of rapidity-differential cross sections of coherent exclusive photoproduction of J/psi mesons in heavy-ion ultraperipheral collisions (UPCs) at the CERN Large Hadron Collider (LHC), d sigma /dy(Pb + Pb -> Pb + J/psi + Pb). For this, we account for the photon-nucleon NLO cross sections at the forward limit, the t dependence using a standard nuclear form factor, and the photon fluxes of the colliding nuclei. Approximating the generalized parton distributions with their forward-limit parton distribution functions (PDFs), we quantify the NLO contributions in the cross sections, show that the real part of the amplitude and quark-PDF contributions must not be neglected, quantify the uncertainties arising from the scale choice and PDFs, and compare our results with ALICE, CMS, and LHCb J/psi photoproduction data in Pb + Pb UPCs, exclusive J/psi photoproduction data from HERA, and LHCb data in p + p. The scale dependence in d sigma /dy(Pb + Pb & RARR; Pb + J/psi + Pb) is significant, but we can find a scale choice that reproduces the Pb + Pb UPC data at both 2.76 and 5.02 TeV collision energies. This process has traditionally been suggested to be a direct probe of nuclear gluon distributions. We show that the situation changes rather dramatically from LO to NLO: the NLO cross sections reflect the nuclear effects of both gluons and quarks in a complicated manner, where the relative signs of the LO and NLO terms in the amplitude play a significant role.Peer reviewe

Do Electronic Cigarettes Increase Cigarette Smoking in UK Adolescents? Evidence from a 12-month Prospective Study

Background In cross-sectional surveys, increasing numbers of adolescents report using both electronic cigarettes (e-cigarettes) and cigarettes. This study assessed whether adolescent e-cigarette use was associated prospectively with initiation or escalation of cigarette use. Methods Data were from 2836 adolescents (aged 13–14 years at baseline) in 20 schools in England. At baseline, breath carbon monoxide levels, self-reported e-cigarette and cigarette use, sex, age, friends and family smoking, beliefs about cigarette use and percentage receiving free school meals (measure of socioeconomic status) were assessed. At 12-month follow-up, self-reported cigarette use was assessed and validated by breath carbon monoxide levels. Results At baseline, 34.2% of adolescents reported ever using e-cigarettes (16.0% used only e-cigarettes). Baseline ever use of e-cigarettes was strongly associated with subsequent initiation (n=1726; OR 5.38, 95% CI 4.02 to 7.22; controlling for covariates, OR 4.06, 95% CI 2.94 to 5.60) and escalation (n=318; OR 1.91, 95% CI 1.14 to 3.21; controlling for covariates, this effect became non-significant, OR 1.39, 95% CI 0.97 to 1.82) of cigarette use. Conclusions This is the first study to report prospective relationships between ever use of e-cigarettes and initiation and escalation of cigarette use among UK adolescents. Ever use of e-cigarettes was robustly associated with initiation but more modestly related to escalation of cigarette use. Further research with longer follow-up in a broader age range of adolescents is required