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See detailCorrelated Wave Functions for Electron–Positron Interactions in Atoms and Molecules
Charry Martinez, Jorge Alfonso UL; Barborini, Matteo UL; Tkatchenko, Alexandre UL

in Journal of Chemical Theory and Computation (2022), 18(4), 22672280

The positron, as the antiparticle of the electron, can form metastable states with atoms and molecules before its annihilation with an electron. Such metastable matter–positron complexes are stabilized by ... [more ▼]

The positron, as the antiparticle of the electron, can form metastable states with atoms and molecules before its annihilation with an electron. Such metastable matter–positron complexes are stabilized by a variety of mechanisms, which can have both covalent and noncovalent character. Specifically, electron–positron binding often involves strong many-body correlation effects, posing a substantial challenge for quantum-chemical methods based on atomic orbitals. Here we propose an accurate, efficient, and transferable variational ansatz based on a combination of electron–positron geminal orbitals and a Jastrow factor that explicitly includes the electron–positron correlations in the field of the nuclei, which are optimized at the level of variational Monte Carlo (VMC). We apply this approach in combination with diffusion Monte Carlo (DMC) to calculate binding energies for a positron e+ and a positronium Ps (the pseudoatomic electron–positron pair), bound to a set of atomic systems (H–, Li+, Li, Li–, Be+, Be, B–, C–, O– and F–). For PsB, PsC, PsO, and PsF, our VMC and DMC total energies are lower than that from previous calculations; hence, we redefine the state of the art for these systems. To assess our approach for molecules, we study the potential-energy surfaces (PES) of two hydrogen anions H– mediated by a positron (e+H22–), for which we calculate accurate spectroscopic properties by using a dense interpolation of the PES. We demonstrate the reliability and transferability of our correlated wave functions for electron–positron interactions with respect to state-of-the-art calculations reported in the literature. [less ▲]

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See detailThe three-center two-positron bond
Charry Martinez, Jorge Alfonso UL; Moncada, Felix; Barborini, Matteo UL et al

in Chemical Science (2022)

Computational studies have shown that one or more positrons can stabilize two repelling atomic anions through the formation of two-center positronic bonds. In the present work, we study the energetic ... [more ▼]

Computational studies have shown that one or more positrons can stabilize two repelling atomic anions through the formation of two-center positronic bonds. In the present work, we study the energetic stability of a system containing two positrons and three hydride anions, namely 2e+[H3-3]. To this aim, we performed a preliminary scan of the potential energy surface of the system with both electrons and positron in a spin singlet state, with a multi-component MP2 method, that was further refined with variational and diffusion Monte Carlo calculations, and confirmed an equilibrium geometry with D3h symmetry. The local stability of 2e+[H3-3] is demonstrated by analyzing the vertical detachment and adiabatic energy dissociation channels. Bonding properties of the positronic compound, such as the equilibrium interatomic distances, force constants, dissociation energies, and bonding densities are compared with those of the purely electronic H+3 and Li+3 systems. Through this analysis, we find compelling similarities between the 2e+[H3-3] compound and the trilithium cation. Our results strongly point out the formation of a non-electronic three-center two-positron bond, analogous to the well-known three-center two-electron counterparts, which is fundamentally distinct from the two-center two-positron bond [D. Bressanini, J. Chem. Phys.155, 054306 (2021)], thus extending the concept of positron bonded molecules. [less ▲]

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See detailAktuelle Entwicklungen im Steuerrecht in der Informationstechnologie 2020/2021 - Teil 2
Sinnig, Julia UL; Schmittmann, Jens M.

in Kommunikation und Recht (2022), 25(3), 175-182

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See detailThe debate on digital taxes and its relevance for Luxembourg
Sinnig, Julia UL

in Cahiers de fiscalité luxembourgeoise et européenne (2022), 1(1), 79-94

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See detailPace of aging, family environment and cognitive skills in children and adolescents
Niccodemi, Gianmaria; Menta, Giorgia; Turner, Jonathan et al

in SSM - Population Health (2022)

Pace of aging is an epigenetic clock which captures the speed at which someone is biologically aging compared to the chronological-age peers. We here use data from the Avon Longitudinal Study of Parents ... [more ▼]

Pace of aging is an epigenetic clock which captures the speed at which someone is biologically aging compared to the chronological-age peers. We here use data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to investigate the interrelation between the study children’s parental social class at birth, and their pace of aging and cognitive skills measures in childhood and adolescence. We show that children from lower parental social classes display faster pace of aging and that the social class gradient in pace of aging is strongest in adolescence. About one third of this association can be explained by other socio-economic and demographic covariates, as well as life events. Similarly, study children’s pace of aging manifests a negative association with their measures of cognitive skills in late adolescence only. This association becomes stronger as the contemporary pace of aging of the mother becomes faster. Our results seem to identify adolescence as the period of life when pace of aging, family environment and cognitive skills measures begin to interact. [less ▲]

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See detailAktuelle Entwicklungen im Steuerrecht in der Informationstechnologie 2020/2021 - Teil 1
Sinnig, Julia UL; Schmittmann, Jens M.

in Kommunikation und Recht (2022), 25(2), 87-92

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See detailBuchbesprechung: Bernadette Duda/Jens M. Schmittmann, Steuerstrafrechtliche Risiken in Krise und Insolvenz, 2. Auflage
Sinnig, Julia UL

in Deutsche Zeitschrift für Wirtschafts- und Insolvenzrecht (2022), (4), 223

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See detailDistance-based social index numbers: a unifying approach
Bossert, Walter; d'Ambrosio, Conchita UL; Weber, Shlomo

in Journal of Mathematical Economics (2022)

We present a unified approach to the design of social index numbers. Our starting point is a model that employs an exogenously given partition of the population into subgroups. Three classes of group ... [more ▼]

We present a unified approach to the design of social index numbers. Our starting point is a model that employs an exogenously given partition of the population into subgroups. Three classes of group-dependent measures of deprivation are characterized. The three groups are nested and, beginning with the largest of these, we narrow them down by successively adding two additional axioms. This leads to a parameterized class the members of which are based on the differences between the income (or wealth) levels of an individual and those who are better off. We then proceed to show that our measures are sufficiently general to accommodate a plethora of indices, including measures of inequality and polarization as well as distance-based measures of phenomena such as diversity and fractionalization. [less ▲]

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See detailThe distributive impact of the Luxembourg tax-benefit system: a more comprehensive measurement
Vergnat, Vincent; d'Ambrosio, Conchita UL; Liégeois, Philippe

in Public Finance Review (2022), 50

This article studies the distribution of income in Luxembourg by integrating two aspects that have been previously neglected: indirect taxation and in-kind transfers. The integration of the latter is ... [more ▼]

This article studies the distribution of income in Luxembourg by integrating two aspects that have been previously neglected: indirect taxation and in-kind transfers. The integration of the latter is essential in Luxembourg, the country with the highest public expenditure per capita in the OECD. These issues have been understudied because of some methodological challenges, including the lack of data containing all the necessary information for this type of analysis. However, with the EUROMOD microsimulation model, different data sources, and imputation methods, we are able to obtain a more complete view of the income distribution in Luxembourg. We find that, as in many developed countries, indirect taxes are regressive. On the other hand, in-kind transfers play an important role in reducing income inequality, in particular through education and health services. [less ▲]

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See detailThe effects of IMF programs on income inequality: a semi-parametric treatment effects approach
Chletsos, Michael; Sintos, Andreas UL

in International Journal of Development Issues (2022)

Purpose This paper aims to provide new insights regarding the impact of International Monetary Fund (IMF) programs on income inequality. Design/methodology/approach The paper uses a novel methodological ... [more ▼]

Purpose This paper aims to provide new insights regarding the impact of International Monetary Fund (IMF) programs on income inequality. Design/methodology/approach The paper uses a novel methodological approach proposed by Acemoglu et al. (2019), using (1) the regression adjustment, (2) the inverse probability weighting and (3) the doubly robust estimator, which combines (1) and (2), and a sample of annual data for 135 developing countries over the time period 1970 to 2015. Findings The findings show that IMF programs are associated with greater income inequality for up to five years. By differentiating the effect of IMF programs, the authors find that only IMF non-concessional programs have a significant detrimental effect on income inequality, while IMF concessional programs do not have a consistent effect on income inequality. In addition, the authors find that only IMF programs with a higher number of conditions have a detrimental and statistically significant effect on income inequality, compared to IMF programs with a smaller number of conditions, where their effect on income inequality is found to be insignificant. Originality/value To the best of the authors’ knowledge, the analysis developed in this paper contributes to the existing literature by applying the most methodologically sound identification strategy, which does not rely on the linearity assumption, the selection of instruments or matching variables and additionally takes into account the selection bias related to IMF program participation. [less ▲]

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See detailIncome-related health inequality in urban China (1991-2015): The role of homeownership and housing conditions
Peng, Nie; Clark, Andrew; d'Ambrosio, Conchita UL et al

in Health and Place (2022), 73

Unprecedented economic growth has been experienced over the several decades worldwide, but such rapid economic growth wasn’t accompanied by equally-substantial improvement in health, especially health ... [more ▼]

Unprecedented economic growth has been experienced over the several decades worldwide, but such rapid economic growth wasn’t accompanied by equally-substantial improvement in health, especially health inequalities between the rich and poor. This study examines the role of housing in income-related health inequalities (income-health gradient) in urban China. We here analyze 1991-2015 China Health and Nutrition Survey data to ask how housing affects income-related health inequalities in urban China. We find pro-poor inequalities in self-reported bad health but pro-rich inequalities in objective bad health (general overweight/obesity, central obesity and high blood pressure). Housing conditions serve to reduce the health gradient, especially for objective health. On the contrary, homeownership exacerbates the health gradient. Improving housing conditions thus appears to be an effective way of reducing the income-health gradient in urban China. [less ▲]

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See detailConstructivism
Heidemann, Dietmar UL

in Kant Yearbook (2022), 14

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See detailRez.: Rolf G. Renner, "Peter Handke. Erzählwelten – Bilderordnungen"
Kohns, Oliver UL

in Zeitschrift für Germanistik (2022), 32(1), 239-241

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See detailMulticast MMSE-based Precoded Satellite Systems: User Scheduling and Equivalent Channel Impact
Lagunas, Eva UL; Ha, Vu Nguyen UL; Chien, Trinh-Van et al

in IEEE 96st Vehicular Technology Conference, London-Beijing, Sept. 2022 (2022)

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See detailQoE-Oriented Resource Allocation Design Coping with Time-Varying Demands in Wireless Communication Networks
Kebedew, Teweldebrhan Mezgebo UL; Ha, Vu Nguyen UL; Lagunas, Eva UL et al

in IEEE 96st Vehicular Technology Conference, London-Beijing, Sept. 2022 (2022)

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See detailHiring in Border Regions: Experimental and Qualitative Evidence from a Recruiter Survey in Luxembourg
Gutfleisch, Tamara; Samuel, Robin UL

in Journal for Labour Market Research (2022), 56

Firms in border regions typically deal with heterogeneous applicant pools that include both (foreign) domestic workers and cross-border commuters. However, we know little about recruiters’ workforce needs ... [more ▼]

Firms in border regions typically deal with heterogeneous applicant pools that include both (foreign) domestic workers and cross-border commuters. However, we know little about recruiters’ workforce needs and hiring practices in cross-border labour markets. Based on a survey of real recruiters in Luxembourg, this study presents experimental and qualitative findings on the role of country of residence in recruiters’ hiring intentions against foreigners. Luxembourg presents a rarely studied but highly relevant case for hiring practices owing to a combination of a strong economy, strict labour market regulations, and a transnational workforce. Drawing on data from a factorial survey experiment, we found no discrimination against Portuguese and French applicants living in Luxembourg. Yet, (highly skilled) cross-border workers from France and Germany faced disadvantages regarding recruiters’ hiring intentions. However, differences in effect sizes between foreigners and cross-border workers were small and not statistically significant. When further asked about the potential challenges of recruiting in Luxembourg’s cross-border labour market, respondents expressed concerns about flexibility, poor social fit, and cultural differences in hiring foreign and cross-border employees. Overall, our study provides further points of reference for studies on hiring intentions in cross-border labour markets across Europe. [less ▲]

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See detailIndividualised prediction of drug resistance and seizure recurrence after medication withdrawal in people with juvenile myoclonic epilepsy: A systematic review and individual participant data meta-analysis
Stevelink, Remi; Al-Toma, Dania; Jansen, Floor E. et al

in eClinicalMedicine (2022)

Summary Background A third of people with juvenile myoclonic epilepsy (JME) are drug-resistant. Three-quarters have a seizure relapse when attempting to withdraw anti-seizure medication (ASM) after ... [more ▼]

Summary Background A third of people with juvenile myoclonic epilepsy (JME) are drug-resistant. Three-quarters have a seizure relapse when attempting to withdraw anti-seizure medication (ASM) after achieving seizure-freedom. It is currently impossible to predict who is likely to become drug-resistant and safely withdraw treatment. We aimed to identify predictors of drug resistance and seizure recurrence to allow for individualised prediction of treatment outcomes in people with JME. Methods We performed an individual participant data (IPD) meta-analysis based on a systematic search in EMBASE and PubMed – last updated on March 11, 2021 – including prospective and retrospective observational studies reporting on treatment outcomes of people diagnosed with JME and available seizure outcome data after a minimum one-year follow-up. We invited authors to share standardised IPD to identify predictors of drug resistance using multivariable logistic regression. We excluded pseudo-resistant individuals. A subset who attempted to withdraw ASM was included in a multivariable proportional hazards analysis on seizure recurrence after ASM withdrawal. The study was registered at the Open Science Framework (OSF; https://osf.io/b9zjc/). Findings  368) was predicted by an earlier age at the start of withdrawal, shorter seizure-free interval and more currently used ASMs, resulting in an average internal-external cross-validation concordance-statistic of 0·70 (95%CI 0·68–0·73). Interpretation We were able to predict and validate clinically relevant personalised treatment outcomes for people with JME. Individualised predictions are accessible as nomograms and web-based tools. Funding MING fonds. [less ▲]

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See detailRaman imaging of twist angle variations in twisted bilayer graphene at intermediate angles
Schäpers, A.; Sonntag, J.; Valerius, L. et al

in 2D Mater. (2022), 9(4), 045009

Van der Waals layered materials with well-defined twist angles between the crystal lattices of individual layers have attracted increasing attention due to the emergence of unexpected material properties ... [more ▼]

Van der Waals layered materials with well-defined twist angles between the crystal lattices of individual layers have attracted increasing attention due to the emergence of unexpected material properties. As many properties critically depend on the exact twist angle and its spatial homogeneity, there is a need for a fast and non-invasive characterization technique of the local twist angle, to be applied preferably right after stacking. We demonstrate that confocal Raman spectroscopy can be utilized to spatially map the twist angle in stacked bilayer graphene for angles between 6.5 and 8 degree when using a green excitation laser. The twist angles can directly be extracted from the moiré superlattice-activated Raman scattering process of the transverse acoustic (TA) phonon mode. Furthermore, we show that the width of the TA Raman peak contains valuable information on spatial twist angle variations on length scales below the laser spot size of ∼500 nm. [less ▲]

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See detailFake News in Literatur und Medien. Fakten und Fiktionen im interdisziplinären Diskurs
Bendheim, Amelie UL; Pavlik, Jennifer

Book published by transcript (2022)

›Fake News‹ sind aus privaten wie politischen Unterhaltungen nicht mehr wegzudenken und erfahren mit der omnipräsenten Nutzung digitaler Kommunikationskanäle eine geradezu inflationäre Verbreitung. Die ... [more ▼]

›Fake News‹ sind aus privaten wie politischen Unterhaltungen nicht mehr wegzudenken und erfahren mit der omnipräsenten Nutzung digitaler Kommunikationskanäle eine geradezu inflationäre Verbreitung. Die Beiträger*innen diskutieren vor dem Hintergrund verschiedener Disziplinen der Humanities Formen und Folgen von Wissens- und Informationsvermittlung, Wahrheitsreduktion und Wirklichkeitsbeschneidung sowie Täuschung und Beeinflussung der öffentlichen Meinung. Sie erschließen den Begriff aus einer interdisziplinären und diachronen Perspektive und eröffnen Einsichten in die verschiedenen Bedeutungsnuancen des Phänomens. [less ▲]

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