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The prevalence of eating difficulties in children and young people in England: A large, cross‐sectional school survey
No full textBackground: Accurate population prevalence estimates of eating difficulties in children and young people provide essential information for the design and implementation of prevention efforts. We aimed to (I) explore the proportion of students reporting eating difficulties in a large English secondary school sample, (II) analyse factors associated with increased odds of eating difficulties and (III) estimate a weighted prevalence of eating difficulties in England. Methods: 19,797 students in school years 7–11 (aged 11–16 years) and 3037 in school years 12–13 (aged 16–19 years) from the OxWell Student Survey completed questions from the Development and Well‐Being Assessment. A further 2664 had answers imputed using multiple imputation by chained equations, resulting in n = 25,498 students. The survey happened during February and March 2023. Logistic regression models estimated associations between gender, year group, ethnic group and eating difficulties. For students in Years 7–11, we estimated the prevalence of eating difficulties weighted to England's population. Results: The most endorsed difficulty was students thinking they were fat when others said they were very thin (47.3%; 11,277/23,837) and the least endorsed was self‐induced vomiting (17.7%; 4203/23,748). Girls (aOR 3.1, 95% CI 2.9, 3.2) and gender diverse/gender non‐disclosing young people (aOR 3.3, 95% CI 2.9, 3.9) had higher odds of having eating difficulties compared to boys, with increasing odds in older year groups. The weighted prevalence of eating difficulties in students in school years 7–11 was 62.5% (95% CI: 61.8, 63.3). Conclusion: The findings show that eating difficulties are common in secondary school students with more than half of our sample self‐reporting at least one type of eating difficulty. These data provide insight for clinical services, and the high prevalence further suggests that early intervention in community settings may have a valuable role in reducing the demand on eating disorder services
Batch Bayesian optimization of attosecond betatron pulses from laser wakefield acceleration
No full textLaser wakefield acceleration can generate a femtosecond-scale broadband X-ray betatron radiation pulse from electrons accelerated by an intense laser pulse in a plasma. The micrometer-scale of the source makes wakefield betatron radiation well-suited for advanced imaging techniques, including diffraction and phase-contrast imaging. Recent progress in laser technology can expand these capabilities into the attosecond regime, where the practical applications would significantly benefit from the increased energy contained within the pulse. Here we use numerical simulations combined with batch Bayesian optimization to enhance the radiation produced by an attosecond betatron source. The method enables an efficient exploration of a multi-parameter space and identifies a regime in which a plasma density spike triggers the generation of a high-charge electron beam. This results in an improvement of more than one order of magnitude in the on-axis time-averaged power within the central time containing half of the radiated energy, compared to the reference case without the density spike
MOdulation‐Guided ENcoding (MOGEN) scheme for vessel‐encoded arterial spin labeling
No full textPurpose
Vessel-encoded arterial spin labeling (VEASL) enables simultaneous, non-contrast imaging of multiple vascular territories that is useful for differential diagnosis and treatment monitoring of cerebrovascular diseases. However, the existing encoding methods are signal-to-noise ratio (SNR) inefficient.
Methods
We developed a MOdulation-Guided ENcoding (MOGEN) scheme that directly exploits the inversion spatial modulation profile to obtain SNR-efficient encoding matrix. Simulations, phantom tests, and healthy volunteer scans were performed to demonstrate its feasibility in multiple application scenarios.
Results
Simulation studies demonstrated that MOGEN achieves significantly higher theoretical SNR efficiency than previous methods for both four- and six-artery configurations. In healthy volunteers, MOGEN improved in vivo SNR by approximately 15% and provided more robust vessel decoding, particularly when the spatial modulation deviated from a cosine profile. In patients with Moyamoya disease, MOGEN enabled reliable visualization of collateral pathways even when scan time was reduced to ˜5 min for six arteries. Furthermore, by considering vessel size with multi-voxel vessel representation, MOGEN enhanced single-artery selectivity in vessel-encoded angiography. We also demonstrated that a straightforward approach of off-resonance correction for VEASL at ultra-high field was feasible by using MOGEN.
Conclusion
MOGEN offered several benefits for VEASL, including high SNR efficiency, flexible spatial modulation and PCASL parameters selection, vessel size consideration, and straightforward off-resonance correction, thereby substantially improving robustness and usability of VEASL across various applications
From CO2 emissions to resource efficiency: a new simplified methodology for assessing resource use in clinker manufacturing
No full textA new simplified methodology for calculating industrial exergy-based Resource Efficiency (RE), estimating clinker manufacturing RE from publicly available CO2 emissions data and existing technical knowledge, is proposed. The analysis builds on previous control-data exergy-based RE analysis of a real cement plant. The results of the two models tested follow the same trends found in the plant’s exergy-based RE analysis employing real-time control-data: fuels dominate total exergetic resource input; the clinker burning section is responsible for the higher consumption of energy and emissions; exhaust gases have significant exergy content, while dust losses are small. Estimation of the raw feed flow from reported CO2 emissions gives a good proxy of the real exergy content of both raw feed and clinker. The use of average EU28 data on fuels yields a fuel mix exergy content which differs by less than 10% of the one obtained employing control-data analysis. The RE results of the models compare well with both those from the control-data analysis and the values reported in the literature. The new proposed methodology is, thus, found to be capable of estimating a plant’s RE that constitutes a good proxy of its real value, using publicly available data
Halide segregation governs interfacial charge-transfer pathways in mixed-halide perovskites
No full textMixed-halide perovskites offer ideal bandgaps for tandem solar cells, but they suffer from light-induced halide segregation, which compromises their operational stability. Here, we directly probe the impact of halide segregation on charge-carrier dynamics at the interface between a mixed-halide perovskite and charge transport layers by using a free-space synchronous multimodal spectroscopy approach, combining time-resolved microwave conductivity, time-resolved photoluminescence (PL) and steady-state PL. We present a method to distinguish directly between charge-carrier dynamics dominated by either majority or minority carriers, enabling us to isolate effects arising from charge-selective extraction from the perovskite to commonly used hole- or electron transport layers, i.e. poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) and SnO2, respectively. We show that halide segregation creates iodide-rich phases that capture charge carriers within sub-nanoseconds, which slightly reduces their mobilities at microwave frequencies. We reveal that charge extraction from such iodide-rich domains is still surprisingly feasible, but competes with enhanced radiative recombination resulting from higher charge concentrations caused by funnelling into these minority phases. We demonstrate that together such effects reduce charge diffusion lengths and can account for the widely observed reduction in open-circuit voltages and short-circuit currents in solar cells under operational conditions. Our findings unravel the causes underpinning the adverse impact of halide segregation and provide guidelines to improve device performance
Neuroanatomical localization of faciobrachial dystonic seizures in LGI1-antibody encephalitis
No full textFaciobrachial dystonic seizures (FBDS), paroxysmal dizziness spells, and thermal sensory attacks are highly frequent and stereotypic phenomena experienced in leucine-rich glioma inactivated 1 (LGI1)-antibody encephalitis. This study aims to describe the electrophysiologic mechanism underlying these pathognomonic symptoms. LGI1-antibody encephalitis patients with active symptoms were enrolled from two separate centers in South Korea and the United States. Patients were evaluated with simultaneous magnetoencephalography (306 channels) and electroencephalography. Regional alterations in neuronal excitability represented by interictal epileptiform discharges were present in the faciobrachial area of the motor cortex, insula, and somatosensory cortex, somatotopically aligned with each of the ictal semiologies observed in patients. FBDS and other LGI1-antibody encephalitis-specific spells localized to cortical regions neuroanatomically corresponding to ictal semiologies: the faciobrachial homunculus (FBDS), insular cortex (paroxysmal dizziness spells), and somatosensory cortex (thermal sensory attacks). Our findings support the ictal hypothesis underlying these unique phenomena
Search for heavy neutral leptons in B-meson decays
No full textA search for long-lived heavy neutral leptons produced in B-meson decays and decaying to a μ±π∓ final state is performed with data collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5 fb−1. The results are interpreted in both lepton-number-conserving and lepton-number-violating scenarios. No significant excess is observed. Constraints are placed on the squared mixing element |UμN|2 to the active muon neutrino, under the assumption that couplings to other lepton flavours are negligible, in the mass range of 1.6–5.5 GeV
Clinically reported covert cerebrovascular disease and risk of neurological disease: a whole-population cohort of 367 988 people using natural language processing
No full textBackground
The relevance of covert cerebrovascular disease (CCD) in practice is uncertain, partly because estimation of risk in whole clinical populations is difficult. Studies have had success extracting CCD from clinical text using natural language processing (NLP), though they have been limited to specific CCD phenotypes. Here, we used NLP to measure multiple clinically-reported CCD phenotypes in a large clinical cohort and estimated subsequent disease risk in health record data.
Methods
From all people with brain imaging in Scotland (2010–2018), we selected people with no prior hospitalisation for neurological disease (n=367 988). NLP of imaging reports identified: white matter hypoattenuation or hyperintensities (WMH), lacunes, cortical infarcts and cerebral atrophy. Adjusted HRs (aHRs) were estimated between each phenotype and stroke, dementia and Parkinson’s disease (conditions previously associated with CCD), epilepsy and colorectal cancer (control conditions).
Results
For each phenotype, the aHR of stroke was WMH 1.4 (95% CI 1.3–1.4), lacunes 1.6 (1.5–1.6), cortical infarct 1.8 (1.7–1.9) and cerebral atrophy 1.1 (1.0–1.1). The aHR of dementia was WMH 1.3 (1.3–1.3), lacunes 1.0 (0.9–1.0), cortical infarct 1.1 (1.1–1.2) and cerebral atrophy 1.7 (1.7–1.8). The aHR of Parkinson’s disease was WMH 1.1 (1.0–1.2), lacunes 1.1 (0.9–1.2), cortical infarct 0.7 (0.6–0.9) and cerebral atrophy 1.4 (1.3–1.5). The aHRs between CCD phenotypes and epilepsy and colorectal cancer were around the null.
Conclusion
CCD and atrophy have implications for future disease risk and can be identified at scale using NLP of clinical reports. Prevention of neurological disease in people with CCD should be a priority for healthcare policy makers
Where ideology matters: evidence from a global analysis of market intervention policies
No full textWhile many studies argue that the ideology of governments affects their policies, most research has focused on OECD countries. This narrow scope is because of a lack of data and common assumptions that political institutions in non-OECD countries extinguish the impact of government ideology. This article challenges these assumptions by analyzing a new dataset on the ideological orientation of governments in 182 countries since 1945. Focusing on market intervention policies, fixed-effects estimates show that government ideology influences certain market intervention tools worldwide, including in non-OECD countries. The analysis further suggests that ideology matters more in countries with fewer constraints on the executive. But counter to common expectations, ideology does not seem to matter more in countries with strong states, democratic institutions, and little clientelism. The findings have important implications for the study of partisan politics, political institutions, and politics in young and non-democracies
Design principles for transpiration cooled ceramic sharp leading edges
No full textTranspiration cooling is an active methodology in reducing surface heat flux for hypersonic vehicles, which offers the possibility of reducing nose bluntness and therefore increasing aerodynamic performance. This paper presents a numerical analysis of transpiration cooled sharp leading edges made from ultra-high-temperature ceramics (UHTCs). The structural integrity of a 10 mm radius wedge leading edge is investigated numerically with regard to different coolant plenum geometries and pressurisation magnitudes. It is found that the close spacing of individual plenum chambers reduces the stress in the material significantly and provides the maximum possible coolant mass flux. An optimisation procedure of plenum pressure distribution is carried out using an analytical description of the porous flow in the leading edge. It is found that there exists an optimum plenum pressure that minimises the probability of failure of the leading edge model. Nitrogen coolant requires less pressure than Helium to reach this criterion and furthermore requires less pressure to displace the air freestream and thus protect the leading edge from oxidation