Aerodynamic characteristics of two-dimensional wing configurations at angles of attack near -90 deg

Wind tunnel tests were conducted to determine the drag of two-dimensional wing sections operating in a near-vertical flow condition. Various leading- and trialing-edge configurations, including plain flaps of 25, 30, and 35% chord were tested at angles of attack from -75 to -105 deg. Reynolds numbers examined ranged from approximately 0.6 x 10 to the 6th power to 1.4 x 10 to the 6th power. The data were obtained using a wind tunnel force and moment balance system and arrays of chordwise pressure orifices. The results showed that significant reductions in drag, beyond what would be expected by virtue of the decreased frontal area, were obtainable with geometries that delayed flow separation. Rapid changes in drag with angle of attack were noted for many configurations. The results, however, were fairly insensitive to Reynolds number variations. Drag values computed from the pressure data generally agreed with the force data within 2%

Test Case Series 1

A simple one-dimensional test case is defined for the purpose of inter-code comparison. This year the focus is set on in-depth physics and chemistry. Material properties, boundary conditions, and output format are provided

Short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude: an update

We reassess the impact of short-distance constraints for the longitudinal component of the hadronic light-by-light amplitude on the anomalous magnetic moment of the muon, $a_\mu=(g-2)_\mu/2$, by comparing different solutions that have recently appeared in the literature. In particular, we analyze the relevance of the exact axial anomaly and its impact on $a_\mu$ and conclude that it remains rather limited. We show that all recently proposed solutions agree well within uncertainties on the numerical estimate of the impact of short-distance constraints on $a_\mu$, despite differences in the concrete implementation. We also take into account the recently calculated perturbative corrections to the massless quark loop to update our estimate and outline the path towards future improvements.Comment: 14 pages, 6 figure

Short-distance constraints on hadronic light-by-light scattering in the anomalous magnetic moment of the muon

A key ingredient in the evaluation of hadronic light-by-light (HLbL) scattering in the anomalous magnetic moment of the muon $(g-2)_\mu$ concerns short-distance constraints (SDCs) that follow from QCD by means of the operator product expansion. Here we concentrate on the most important such constraint, in the longitudinal amplitudes, and show that it can be implemented efficiently in terms of a Regge sum over excited pseudoscalar states, constrained by phenomenological input on masses, two-photon couplings, as well as SDCs on HLbL scattering and the pseudoscalar transition form factors (TFFs). Our estimate of the effect of the longitudinal SDCs on the HLbL contribution is: $\Delta a_\mu^\text{LSDC}=13(6)\times 10^{-11}$. This is significantly smaller than previous estimates, which mostly relied on an ad-hoc modification of the pseudoscalar poles and led to up to a $40\%$ increase with respect to the nominal pseudoscalar-pole contributions, when evaluated with modern input for the relevant TFFs. We also comment on the status of the transversal SDCs and, by matching to perturbative QCD, argue that the corresponding correction will be significantly smaller than its longitudinal counterpart.Comment: 7 pages, 2 figures; journal versio

Longitudinal short-distance constraints for the hadronic light-by-light contribution to (g−2)μ(g-2)_\mu with large-NcN_c Regge models

While the low-energy part of the hadronic light-by-light (HLbL) tensor can be constrained from data using dispersion relations, for a full evaluation of its contribution to the anomalous magnetic moment of the muon $(g-2)_\mu$ also mixed- and high-energy regions need to be estimated. Both can be addressed within the operator product expansion (OPE), either for configurations where all photon virtualities become large or one of them remains finite. Imposing such short-distance constraints (SDCs) on the HLbL tensor is thus a major aspect of a model-independent approach towards HLbL scattering. Here, we focus on longitudinal SDCs, which concern the amplitudes containing the pseudoscalar-pole contributions from $\pi^0$, $\eta$, $\eta'$. Since these conditions cannot be fulfilled by a finite number of pseudoscalar poles, we consider a tower of excited pseudoscalars, constraining their masses and transition form factors from Regge theory, the OPE, and phenomenology. Implementing a matching of the resulting expressions for the HLbL tensor onto the perturbative QCD quark loop, we are able to further constrain our calculation and significantly reduce its model dependence. We find that especially for the $\pi^0$ the corresponding increase of the HLbL contribution is much smaller than previous prescriptions in the literature would imply. Overall, we estimate that longitudinal SDCs increase the HLbL contribution by $\Delta a_\mu^\text{LSDC}=13(6)\times 10^{-11}$. This number does not include the contribution from the charm quark, for which we find $a_\mu^{c\text{-quark}}=3(1)\times 10^{-11}$.Comment: 85 pages, 33 figures, 5 tables; journal version, includes reply to arXiv:1911.0587

Initial soil carbon losses may offset decades of biomass carbon accumulation in Mediterranean afforestation

Afforestation of degraded areas was suggested as CO2 sink, contributing to climate change mitigation. Yet, few studies have assessed this sink by combining measurements on carbon (C) in the biomass and the soil, despite it being crucial to properly estimate the mitigation potential. Here, we assessed the combined C stocks of afforestation plots of different ages on former cropland in a Cambisol landscape in Extremadura, Spain. The plots were afforested with two native tree species (Quercus ilex L. and Quercus suber L. in a density ratio of 3:1), planted at several occasions between 1998 and 2011. Stocks of afforested areas in 2022 were compared to non-afforested negative controls on arable land, to a closeby olive grove and a forest with signs of degradation. Tree biomass was estimated from allometric equations, soil organic carbon (SOC) stocks were measured to 30 cm depth, based on equivalent soil mass. The biomass C accumulation rate in afforested plots increased with tree density and elevation (p <0.05; range: 25 to 75 g C m2 yr 1). SOC stocks, in contrast, were not significantly different in afforested and non-afforested plots at any depth and in tendency even lower in afforested plots younger than 20 years. Consequently, total (biomass plus soil) C stocks in afforested plots were not significantly higher than in non-afforested ones. Nevertheless, SOC stocks and contents between the tree rows were significantly lower compared to soil next to the trees in the olive grove (about 1200 vs. 2200 g C m2 in the top 30 cm) and in tendency in the afforested plots (about 1200 vs. 1500 g C m2 in the top 30 cm; p <0.1). The fact that the degraded forest (about 6800 g C m2) and the olive grove (about 5300 g C m2) did have significantly higher total C stocks than the afforested and non-afforested sites (about 2300 and 1800 g C m2) could indicate that afforestation could soon become a C sink. However, our study clearly shows that afforestation is not automatically a C sink. Timing of different C pools` losses and gains affect net ecosystem carbon sequestration. While improved soil management in afforestation may reduce SOC losses, afforestation with Mediterranean Quercus trees under current management practices may require decades before being a C sink. This finding should temper expectations that afforestation with such tree species is a rapid solution to combat climate change

Longitudinal changes of mental health problems in children and adolescents treated in a primary care-based health-coaching programme – results of the PrimA-QuO cohort study

BACKGROUND: In Germany, 19.1% of boys and 14.5% of girls are affected by mental health problems (MHP). Paediatricians are usually the first in line to be contacted but they often do not feel adequately trained to diagnose and treat MHP in primary care. A major statutory health insurance fund introduced a health coaching (HC) programme to strengthen primary care consultation for MHP. The HC includes a training concept for paediatricians, standardised guidelines for actions and additional payments. The aim of this study was to investigate the potential effects of the HC programme on the change of MHP in children and adolescents. METHODS: A prospective cohort study was conducted in Bavaria, Germany, in 2018 and 2019. Data were collected at 2 points 1 year apart using an online questionnaire. Parents of patients with developmental disorder of speech and language, head/abdominal pain, conduct disorder or non-organic enuresis were approached by their health insurance. Families treated according to the HC programme form the intervention group while all others serve as controls. MHP was assessed using the Strengths and Difficulties Questionnaire (SDQ) as a child self-assessment (SDQ-S)/or external assessment by parents (SDQ-P). Determinants of SDQ total score were analysed using linear mixed effects models. RESULTS: Cross-sectional (n = 1090) and longitudinal analyses (n = 599) were performed. At baseline, a total of 23.5% had an SDQ total score “at risk” (SDQ-S > 15/SDQ-P > 13). There were no significant differences between intervention and controls. After full adjustment for all potential confounders, higher SDQ scores indicating more problems were significantly associated with male sex (2.000, p < 0.001) whereas a high parental education level was significantly associated with decreased SDQ scores (-2.127, p =0.034). There was a significant improvement in the control group over time (-0.814, p = 0.001) while the SDQ scores in the intervention group remained stable (-0.012, p = 0.020). CONCLUSION: This evaluation of the HC programme could not prove a clinically relevant intervention’s effect on the MHP developmental course. Nevertheless, (HC) paediatricians have crucial potential to improve the care of MHP patients. Targeting families with less access to support measures might help reduce the burden of MHP and be a step towards continuous improvement of care. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12875-022-01780-1

Mixed-methods evaluation of a structured primary care programme for children and adolescents with mental health problems (PrimA-QuO): a study protocol

INTRODUCTION More than 17% of German children and adolescents have clinically relevant mental health problems (MHP). Typically, general paediatricians are often the first contact for children with MHP, and referrals to specialised care tend to be the standard approach. A statutory health insurance fund developed a programme for children with MHP (Health Coaching (HC)) aiming to offer targeted but low-threshold services. However, little is known about whether HC has the potential for optimising patient care. The aim of the PrimA-QuO study is to examine the effectiveness and the acceptance, barriers and facilitators of all stakeholders of this structured primary care programme for children affected by the most frequently encountered MHP in paediatric practice. METHODS AND ANALYSIS In this mixed-methods approach, children (n=800; aged 0-17 years) with MHP meeting all inclusion criteria will be identified in the health insurance database according to International Classification of Diseases, 10th Revision diagnoses between 2018 and 2019. The qualitative component uses a series of semistructured interviews with programme developers, paediatricians trained in HC, adolescents with MHP treated according to the programme guidelines and their parents. In addition, a prospective, pragmatic, parallel-group cohort study will be conducted using an online questionnaire to examine the effects of HC on health-related quality of life of affected children and their families as well as on change in MHP. Children treated according to the HC guidelines form the intervention group, whereas all others serve as controls. Primary data from the cohort study are linked to children's health insurance claims data to calculate the costs of care as proxies for healthcare utilisation. The hypothesis is that HC is an effective and efficient primary care programme with the potential to improve patients' and their families' health outcomes. ETHICS AND DISSEMINATION The study was approved by the Ethical Committee of Ludwig-Maximilians-Universität München. Grant number 01VSF16032 (funded by the German Innovationsfonds)

Computation with Advice

Computation with advice is suggested as generalization of both computation with discrete advice and Type-2 Nondeterminism. Several embodiments of the generic concept are discussed, and the close connection to Weihrauch reducibility is pointed out. As a novel concept, computability with random advice is studied; which corresponds to correct solutions being guessable with positive probability. In the framework of computation with advice, it is possible to define computational complexity for certain concepts of hypercomputation. Finally, some examples are given which illuminate the interplay of uniform and non-uniform techniques in order to investigate both computability with advice and the Weihrauch lattice