bluuebunny/crossref_metadata_2025 huggingface dataset:
Laser induced white emission of diamond
Authors: Strek W. , Oleszko M. , Wiewiórski O. , Tomala R. , Konovalova A. , Ignatenko O. , Chaika M.
Published: October 2022

Laser-induced white emission of diamond was investigated under irradiation with a focused beam of an infrared laser diode. It is a surface-related coherent emission, characterized by an excitation threshold and an exponential dependence on pumping laser power. The mechanism of white emission is discussed in terms of multiphoton ionization of carbon atoms in an irradiated spot. The excitation power dependence of white emission intensity has demonstrated hysteresis loop behavior. This phenomenon could be useful in new broadband laser sources and optical information storage.
Reinvestigation of the Herzberg-Lagerqvist-Malmberg transitions of C2 in vacuum ultraviolet region and the implications for astronomical observations
Authors: Yin Tonghui , Ma Liying , Cheng Min , Gao Hong
Published: October 2022

The dicarbon radical, C2, is one of the most abundant molecules in the universe, and has been widely observed in various energetic environments. Even though numerous experimental and theoretical investigations on C2 have been done during the last two centuries, spectroscopic study of C2 in vacuum ultraviolet (VUV) region has been rare. The only three known absorption band systems in VUV region were identified by Herzberg and co-workers in 1969 by VUV spectrograph, namely the electronic transitions F1Πu(v′)–X1Σg+(v″), f3Σg−(v′)–a3Πu(v″) and g3Δg(v′)–a3Πu(v″) (Herzberg-Lagerqvist-Malmberg transitions). In this study, we employ a two-photon resonance-enhanced four-wave mixing based VUV laser source and a time-of-flight mass spectrometer for reinvestigating the above three electronic transitions of C2 through a resonant (1VUV + 1′UV) photoionization scheme. Besides those vibronic transitions as identified by Herzberg and co-workers, many more absorption bands belonging to the electronic transitions f3Σg−(v′)–a3Πu(v″) and g3Δg(v′)–a3Πu(v″) are observed with their spectroscopic parameters determined. The rather astrophysically important F1Πu state is not observed here by the resonant (1VUV + 1′UV) photoionization scheme, which must be due to its fast predissociation process. Instead, our study shows that the vibronic band g3Δg(v′ = 2)–a3Πu(v″ = 0) exactly overlaps with F1Πu(v′ = 0)–X1Σg+(v″ = 0), which was not realized in previous studies. The potential implications of these findings to astronomical observations are discussed.
Development of a novel ReaxFF reactive potential for organochloride molecules
Authors: Wolf Matthieu , Bégué Didier , Salvato Vallverdu Germain
Published: October 2022

This article presents a new reactive potential in the ReaxFF formalism. It aims to include the chlorine element and opens up the fields of use of ReaxFF to the whole class of organochloride compounds including conjugated or aromatic groups. Numerous compounds in this family raise global awareness due to their environmental impact, and such a reactive potential will help investigate their degradation pathways. The new force field, named CHONCl-2022_weak, belongs to the aqueous branch. The force field parameters were fitted against high-level quantum chemistry calculations, including complete active space self-consistent field/NEVPT2 calculations and density functional theory calculations, and their accuracy was evaluated using a validation set. The root means square deviation against quantum mechanics energies is 0.38 eV (8.91 kcal mol−1). From a structural point of view, the root means square deviation is about 0.06 Å for the bond lengths, 11.86° for the angles, and 4.12° for the dihedral angles. With CHONCl-2022_weak new force field, we successfully investigated the regioselectivity for nucleophilic or electrophilic attacks on polychlorinated biphenyls, which are toxic and permanent pollutants. The rotation barriers along the bond linking the two benzene rings, which is crucial in the toxicity of these compounds, are well reproduced by CHONCl-2022_weak. Then, our new reactive potential is used to investigate the chlorobenzene reactivity in the presence of hydroxyl radicals in atmospheric condition or in aqueous solution. The reaction pathways computed with ReaxFF agree with the quantum mechanics results. We showed that, in the presence of dioxygen molecules, in atmospheric condition, the oxidation of chlorobenzene likely leads to the formation of highly oxygenated compounds after the abstraction of hydrogen radicals. In water, the addition of a hydroxyl radical leads to the formation of chlorophenol or phenol molecules, as already predicted from plasma-induced degradation experiments.
Phase separation during sedimentation of dilute bacterial suspensions
Authors: Torres Maldonado Bryan O. , Ran Ranjiangshang , Galloway K. Lawrence , Brosseau Quentin , Pradeep Shravan , Arratia Paulo E.
Published: October 2022

Numerous natural systems depend on the sedimentation of passive particles in the presence of swimming microorganisms. Here, we investigate the dynamics of the sedimentation of spherical colloids at various E. coli concentrations within the dilute regime. Results show the appearance of two sedimentation fronts: a spherical particle front and the bacteria front. We find that the bacteria front behave diffusive at short times, whereas at long times it decays linearly. The sedimentation speed of passive particles decays at a constant speed and decreases as bacteria concentration (ϕb) is increased. As ϕb is increased further, the sedimentation speed becomes independent of ϕb. The timescales of the bacteria front are associated with the particle settling speeds. Remarkably, all experiments collapse onto a single master line by using the bacteria front timescale. A phenomenological model is proposed that captures the sedimentation of passive particles in active fluids.
Identity of the reversible hole traps in InP/ZnSe core/shell quantum dots
Authors: Kelley Anne Myers , Cavanaugh Paul , Sun Haochen , Wang Xudong , Bautista Maria J. , Jen-La Plante Ilan , Ippen Christian , Kelley David F.
Published: October 2022

Density functional theory calculations are combined with time-resolved photoluminescence experiments to identify the species responsible for the reversible trapping of holes following photoexcitation of InP/ZnSe/ZnS core/shell/shell quantum dots (QDs) having excess indium in the shell [P. Cavanaugh et al., J. Chem. Phys. 155, 244705 (2021)]. Several possible assignments are considered, and a substitutional indium adjacent to a zinc vacancy, In3+/VZn2−, is found to be the most likely. This assignment is consistent with the observation that trapping occurs only when the QD has excess indium and is supported by experiments showing that the addition of zinc oleate or acetate decreases the extent of trapping, presumably by filling some of the vacancy traps. We also show that the addition of alkyl carboxylic acids causes increased trapping, presumably by the creation of additional zinc vacancies. The calculations show that either a single In2+ ion or an In2+–In3+ dimer is much too easily oxidized to form the reversible traps observed experimentally, while In3+ is far too difficult to oxidize. Additional experimental data on InP/ZnSe/ZnS QDs synthesized in the absence of chloride demonstrates that the reversible traps are not associated with Cl−. However, a zinc vacancy adjacent to a substitutional indium is calculated to have its highest occupied orbitals about 1 eV above the top of the valence band of bulk ZnSe, in the appropriate energy range to act as reversible traps for quantum confined holes in the InP valence band. The associated orbitals are predominantly composed of p orbitals on the Se atoms adjacent to the Zn vacancy.
The US Forest Service Life First safety initiative: exploring unnecessary exposure to risk
Authors: Flores David , Haire Emily R.
Published: October 2022

In 2016, the US Forest Service initiated small-group safety discussions among members of its wildland firefighting organisation. Known as the Life First National Engagement Sessions, the discussions presented an opportunity for wildland firefighters to address systemic and cultural dysfunctions in the wildland fire system. The Life First initiative included a post-engagement survey in which more than 2600 Forest Service employees provided open-ended feedback. In that qualitative subset of results, survey respondents described four main situations in which wildland firefighters commonly accepted unnecessary exposure to risk, related to driving, mop up, aviation and communication. Findings reveal how firefighters experienced social, political and economic pressures upon and within the wildland fire system. They shared that these perceived pressures and their mission-oriented work culture interacted, transforming otherwise unremarkable work operations into situations of unnecessary exposure to risk.
Facing the challenges of endemic African Swine Fever in Vietnam
Authors: Lai Danh Cong , Le Hong Nho Thi , Nga Bui Thi To , Do Duy Tien
Published: October 2022

The objective of this article is to review and evaluate the epidemiological transition of African swine fever (ASF) from a typical epidemic to an endemic situation in Vietnam, and thereby propose appropriate solutions for disease prevention and re-herding for countries with similar situations. In the first year of its introduction, ASF has had a great impact on Vietnam’s pig industry, with the total number of households, the number of pig heads, and pork production decreasing sharply along with a marked change in structure and model. However, the Vietnamese pig herd has experienced rapid recovery and growth in the following two years, and ASF outbreaks have occurred much less frequently. The spread of ASFV in infected farms in Vietnam is reported to be very rapid, which is due to the very special epidemiological characteristics of ASF in pigs raised in Vietnam. Although vaccine ASF-G-Δl177L was commercialized in the endemic ASF context of Vietnam, changing the mindset of livestock production towards safer and more sustainable with strict implementation of biosecurity measures with a new approach is an effective key to disease control and prevention.
Core-resonance line-shape analysis of atoms undergoing strong-field ionization
Authors: Hartmann M , Hutcheson L , Borisova G D , Birk P , Hu S , Brown A C , van der Hart H W , Ott C , Pfeifer T
Published: October 2022

Using attosecond transient absorption spectroscopy for time delays where the near-infrared pump and the extreme ultraviolet (XUV) probe pulses overlap, sub-cycle structures in the build-up of absorption lines in xenon ions are investigated as a function of the pump intensity during strong-field ionization. We observe a half-cycle-periodic change in the line-shape asymmetry of the ionic 4d–5p resonances. Analyzing the line shapes, we find that in particular the phase of the induced dipole emission is modified, and the magnitude of this phase modulation decreases with increasing laser intensity. We discuss the influence of ground state depletion on interfering pathways involved in XUV-assisted strong-field ionization.
Second-order phase transition of silicon from a band insulator to metal induced by strong magnetic fields
Authors: Higuchi Katsuhiko , Hamal Dipendra Bahadur , Higuchi Masahiko
Published: October 2022

We present the second-order phase transition from a band insulator to metal that is induced by a strong magnetic field. The magnetic-field dependences of the magnetization and energy band gap of a crystalline silicon immersed in a magnetic field are investigated by means of the nonperturbative magnetic-field-containing relativistic tight-binding approximation method (2018 Phys. Rev. B 97 195135). It is shown that the energy band gap disappears at the critical magnetic field of 2.22 × 104 (T). At the critical magnetic field, the magnetic-field dependence of the magnetization exhibits a kink behavior, which means that this phenomenon is the second-order phase transition from a band insulator to metal. It is found that in strong magnetic fields above the critical magnetic field, namely in the metallic phase, the oscillation of the magnetization appears. It is shown that this magnetic oscillation comes from the magnetic energy bands in the magnetic Brillouin zone that change from the occupied states to unoccupied states or vice vasa.
Horocycle Dynamics: New Invariants and Eigenform Loci in the Stratum ℋ(1,1)
Authors: Bainbridge Matt , Smillie John , Weiss Barak
Published: October 2022

We study dynamics of the horocycle flow on strata of translation surfaces, introduce new invariants for ergodic measures, and analyze the interaction of the horocycle flow and real Rel surgeries. We use this analysis to complete and extend results of Calta and Wortman classifying horocycle-invariant measures in the eigenform loci. In addition we classify the horocycle orbit-closures and prove that every orbit is equidistributed in its orbit-closure. We also prove equidistribution results describing limits of sequences of measures. Our results have applications to the problem of counting closed trajectories on translation surfaces of genus 2.
Legal Pluralism and the Struggle for Customary Law in the Vietnamese Highlands
Authors: Gillespie John , Quang Tran Hong Thi
Published: October 2022

For centuries, diverse groups of people living in the highlands of Southeast Asia have resisted lowland empires in China, Myanmar, Thailand, and Vietnam. The interaction between lowlanders and highlanders has been described as “internal colonization”—a process involving the absorption or displacement of highland communities and customary law. This Article draws on an empirical study to explore whether the Vietnamese Government’s new “village covenant” (Hương ước) program is continuing internal colonization by transforming and displacing customary law in the Vietnamese Central Highlands. It uses a novel analytical framework—synthetized from legal pluralism and systems theory—to argue the state legal system and highland communities lack a shared conceptual grammar in which to identify common ground, reconcile differences, and converge. The Article closes with the conclusion that, although highland communities are resisting internal colonization, the forces of modernity are slowly changing the deeply held epistemic assumptions underlying customary law.
Independent effects of emotional arousal and reward anticipation on episodic memory formation
Authors: Gieske Astrid , Sommer Tobias
Published: October 2022

Events that elicit emotional arousal or are associated with reward are more likely remembered. Emotional arousal activates the amygdala and the central noradrenergic system, whereas reward anticipation results in an activity in the mesocorticolimbic dopaminergic system. The activation of both pathways enhances memory formation in the hippocampus where their effects are based on similar neural substrates, e.g. tagging of active hippocampal synapses. Moreover, emotional arousal and reward anticipation both enhance attention, which can also affect memory formation. In addition, both neuromodulators interact on the cellular level. Therefore, we tested in the current functional magnetic resonance imaging study whether simultaneously occurring emotional arousal and reward anticipation might have interacting effects on memory formation. We did not find evidence for such an interaction, neither on the behavioral nor on the neural level. Our results further suggest that reward anticipation enhances memory formation rather by an increase in anticipation-related arousal—reflected in activity in the dorsal anterior cingulate cortex—and not dopaminergic midbrain activity. Accompanying behavioral experiments indicated that the effect of reward anticipation on memory is (i) caused at least to some extent by anticipating the speeded response to obtain the reward and not by the valance of the outcome and (ii) can be observed already immediately after encoding, i.e. before consolidation.
Influence of Care Network Characteristics on Physician Visit Experiences for Black, White, and Hispanic Older Adults With Dementia
Authors: Wyman Mary F , Vega Irving E , Cabrera Laura Y , Amini Reza , Kim Kyeongmo , Tarraf Wassim
Published: October 2022

Objectives

Most older adults with dementia are assisted by multiple caregivers, but the relationship of care network structure with health care access and quality is underexamined. We sought to test the associations of care network characteristics with the physician visit experience for older adults with dementia across diverse racial/ethnic groups.

Methods

We used data on Medicare beneficiaries (aged 65+) with dementia from the National Health and Aging Trends Study (2015–2019) to fit logistic regression models to test associations between physician visit outcomes and (a) size of the potential care network and (b) proportion of potential care network members (PCNMs) currently helping with daily functioning tasks. We also tested for modifications by race/ethnicity.

Results

Hispanic respondents had the largest potential care networks (M = 6.89, standard deviation [SD] = 3.58) and the smallest proportion of PCNMs providing help with daily functioning (M = 29.89%, SD = 22.29). In models adjusted for demographics and dementia classification, both network size and proportional involvement of PCNMs were positively associated with the presence of a PCNM and assistance during the visit. Associations remained significant at 4-year follow-up for the presence of PCNM at the visit and were robust to further adjustments for insurance type, income, and health factors. Associations were not modified by race/ethnicity.

Discussion

Larger networks and a higher proportion of PCNMs providing assistance predicted caregiver presence and assistance at the physician visit but not access to care. Findings suggest that strengthening care networks early in the disease may support improved health care outcomes for persons with dementia across diverse populations.
Deformations of Semi-Smooth Varieties
Authors: Fantechi Barbara , Franciosi Marco , Pardini Rita
Published: October 2022

For a singular variety $X$, an essential step to determine its smoothability and study its deformations is the understanding of the tangent sheaf and of the sheaf $\mathcal {T}^{1}_{X}:={{\mathcal {E}}xt}^{1}(\Omega _{X},\mathcal {O}_{X})$. A variety is semi-smooth if its singularities are étale locally the product of a double crossing point ($uv=0$) or a pinch point ($u^2-v^2w=0$) with affine space; equivalently, if it can be obtained by gluing a smooth variety along a smooth divisor via an involution with smooth quotient. Our main result is the explicit computation of the tangent sheaf and the sheaf $\mathcal {T}^{1}_{X}$ for a semi-smooth variety $X$ in terms of the gluing data.
Two-Point Boundary Value Problems on Diffeomorphism Groups
Authors: Heslin Patrick
Published: October 2022

We consider a variety of geodesic equations on Sobolev diffeomorphism groups, including the equations of ideal hydrodynamics. We prove that solutions of the corresponding two-point boundary value problems are precisely as smooth as their boundary conditions. We further utilise this regularity property to construct continuously differentiable exponential maps in the Frechét setting.
On Explicit Representations of Isotropic Measures in John and Löwner Positions
Authors: Baêta Fernanda Moreira , Haddad Julián
Published: October 2022

Given a convex body $K \subseteq {{\mathbb {R}}}^n$ in Löwner position, we study the problem of constructing a non-negative centered isotropic measure supported in the contact points, whose existence is guaranteed by John’s Theorem. The method we propose requires the minimization of a convex function defined in an $\frac {n(n+3)}2$ dimensional vector space. We find a geometric interpretation of the minimizer as $\left . \frac {\partial }{\partial r}(A_r, v_r)\right |_{r=1}$, where $A_r K + v_r$ is a one-parameter family of positions of $K$ that are in some sense related to the maximal intersection position of radius$r$ defined recently by Artstein-Avidan and Katzin.
Optimal Range of Haar Martingale Transforms and Its Applications
Authors: Astashkin Sergey , Huang Jinghao , Pliev Marat , Sukochev Fedor , Zanin Dmitriy
Published: October 2022

Let $({{\mathcal {F}}}_n)_{n\ge 0}$ be the standard dyadic filtration on $[0,1)$. Let ${\mathbb {E}}_{{{\mathcal {F}}}_n}$ be the conditional expectation from $ L_1=L_1[0,1)$ onto ${{\mathcal {F}}}_n$, $n\ge 0$, and let ${\mathbb {E}}_{{{\mathcal {F}}}_{-1}} =0$. We present the sharp estimate for the distribution function of the martingale transform $T$ defined by $$ \begin{align*} Tf=\sum_{m=0}^\infty \left( \mathbb{E}_{\mathcal{F}_{2m}} f-\mathbb{E}_{\mathcal{F}_{2m-1}}f \right), ~f\in L_1, \end{align*}$$in terms of the classical Calderón operator. As an application, for a given symmetric function space $E$ on $[0,1)$, we identify the symmetric space $\mathcal {S}_E$, the optimal Banach symmetric range of martingale transforms/Haar basis projections acting on $E$.
Oscillation of the Remainder Term in the Prime Number Theorem of Beurling, “Caused by a Given ζ-Zero”
Authors: Révész Szilárd Gy.
Published: October 2022

Continuing previous studies of the Beurling zeta function, here, we prove two results, generalizing long existing knowledge regarding the classical case of the Riemann zeta function and some of its generalizations. First, we address the question of Littlewood, who asked for explicit oscillation results provided a zeta-zero is known. We prove that given a zero $\rho _0$ of the Beurling zeta function $\zeta _{{\mathcal {P}}}$ for a given number system generated by the primes ${\mathcal {P}}$, the corresponding error term $\Delta (x):=\psi _{{\mathcal {P}}}(x)-x$, where $\psi _{{\mathcal {P}}}(x)$ is the von Mangoldt summatory function shows oscillation in any large enough interval, as large as $\frac {\pi /2-\varepsilon }{|\rho _0|}x^{\Re \rho _0}$. The somewhat mysterious appearance of the constant $\pi /2$ is explained in the study. Finally, we prove as the next main result of the paper the following: given $\varepsilon>0$, there exists a Beurling number system with primes ${\mathcal {P}}$, such that $|\Delta (x)| \le \frac {\pi /2+\varepsilon }{|\rho _0|}x^{\Re \rho _0}$. In this 2nd part, a nontrivial construction of a low norm sine polynomial is coupled by the application of the wonderful recent prime random approximation result of Broucke and Vindas, who sharpened the breakthrough probabilistic construction due to Diamond, Montgomery, and Vorhauer.
A Delphi consensus study to identify priorities for improving and measuring medication safety for intensive care patients on transfer to a hospital ward
Authors: Bourne Richard S , Jennings Jennifer K , Ashcroft Darren M
Published: October 2022

Background

Intensive care patients surviving to transfer to a lower-acuity hospital ward experience ongoing challenges to their recovery and lack a well-defined and developed care pathway. The transfer process to a hospital ward exposes intensive care patients to high rates of medication errors, which increase their risk of adverse drug events.

Objective

The aims of this study were to identify priorities for medication-related intervention components and outcome measures for improving medication safety for intensive care patients transferring to a hospital ward.

Methods

Three panels involving 129 participants covering (i) intensive care, (ii) hospital ward health-care professionals and (iii) public representatives completed an electronic Delphi survey conducted over three phases. The Delphi process comprised three sections (medication-related intervention components, medication outcomes and patient outcomes). Items were graded in their level of importance, with predefined important criteria. Item agreement required consensus across all three panels. Intervention barriers and facilitators identified in participant comments were categorized according to a socio-technical systems approach to the patient journey and patient safety (Systems Engineering Initiative for Patient Safety 3.0 model).

Results

Of the 129 (84.5%) participants, 109 completed all three Delphi phases. Consensus was achieved for 48 intervention components, 13 medication outcome measures and 11 patient outcome measures. Phase 1 provided 158 comments comprising >200 individual barriers and facilitators to intervention delivery. Frequently cited facilitators included clearly specified roles and responsibilities (10.7% (organizational conditions)), patient and family as agents (8.8% (care team)), medicines-related information easily accessible (7.8% (tools and technologies)) and clear medication plan and communication (7.3% (tasks)).

Conclusions

Our findings provide identification of priorities for medication-related intervention components to improve medication safety for intensive care patients transferring to a hospital ward. Prioritization is complemented by the identification and socio-technical categorization of barriers and facilitators to intervention delivery. The identified important medication and patient outcomes to measure will inform the design of a future patient medication safety intervention study.
Predictive score for patients with carbapenemase-producing enterobacterales colonization upon admission in a tertiary care hospital in an endemic area
Authors: Papafotiou Chrysanthe , Roussos Sotirios , Sypsa Vana , Bampali Sofia , Spyridopoulou Kalliopi , Karapanou Amalia , Moussouli Anastasia , Samarkos Michael , Daikos George L , Psichogiou Mina
Published: October 2022

Objectives

Carbapenemase-producing Enterobacterales (CPE) comprise important nosocomial pathogens worldwide. Colonized patients are the source of further dissemination in healthcare settings. Considering that timely detection of CPE carriers is pivotal but universal screening is unfeasible, we aimed to develop and validate a prediction score to detect patients harbouring CPE on hospital admission.

Methods

The study was conducted in a tertiary care hospital located in a CPE endemic area. Rectal swabs were obtained from 2303 patients, screened shortly after hospital admission. The Enterobacterales isolated in cultures were examined for the presence of blaVIM, KPC, NDM, OXA-48 by PCR. Demographic data and patient history of the previous 6 months were recorded. Risk factors for CPE carriage were identified using a multivariable logistic regression model and a points-system risk score was developed. The discriminative ability of the risk score was assessed using the AUC and its predictive performance was validated in a second dataset of 1391 patients in a different time period.

Results

Seven predictors were identified: previous CPE colonization or infection, prior hospitalization, stay in a long-term health care facility, history of ≥2 interventions, renal replacement therapy, diabetes with end-organ damage and Karnofsky score. The developed risk score in the derivation dataset ranged between 0 and 79 points, with an AUC of 0.84 in the derivation and 0.85 in the validation dataset.

Conclusions

This prediction tool may assist in identifying patients who are at risk of harbouring CPE on hospital admission in an endemic area and guide clinicians to implement prompt and appropriate infection control measures.
Sexual Assault: Approach to Reality in the Area of Santiago de Compostela (Galicia, Spain) through a 12-Year Retrospective Study
Authors: Cabarcos-Fernández P , Tabernero-Duque M J , Álvarez-Freire I , Bermejo-Barrera A M
Published: October 2022

Sexual assault constitutes a severely traumatic experience that impacts the lives of far too many victims each year. The underlying behaviors of the offenders are often associated with psychological, physical and social distress, and the use of psychotropic substances was found in a good number of cases. A descriptive and retrospective review of sexual assault cases has been undertaken to identify trends in the toxicology findings in Drug-Facilitated Sexual Assault in Santiago de Compostela over the past 12 years. During this period, a total of 69 cases were referred to the Forensic Toxicology Service as sexual assault cases. The sex and age distribution of the cases showed that females between the ages of 14 and 65 years constituted the group most frequently submitted to sexual assault, with a peak of 55.1% in the 18- to 30-year age group. Alcohol consumption was positive in 77.1% of positive cases determined, followed by drugs (34.4%) and illicit drugs (26.2%). Our results showed a high percentage of alcohol consumption in sexual assault cases.
Towards super-resolution via iterative multi-exposure coaddition
Authors: Wang Lei , Li Guoliang , Kang Xi
Published: October 2022

In this article, we provide an alternative upsampling and point-spread function (PSF) deconvolution method for iterative multi-exposure coaddition. In contrast to previous works, the new method has a ratio-correction term, which allows the iterations to converge more rapidly to an accurate representation of the underlying image than methods with difference-correction terms. By employing this method, one can coadd undersampled multi-exposures to a super-resolution and obtain a higher peak signal-to-noise ratio. A set of simulations shows that there are many advantages of the new method, e.g. in the signal-to-noise ratio, average deviation of all source fluxes, super-resolution, and source distortion ratio, which are friendly to astronomical photometry and morphology and benefit faint source detection and shear measurement of weak gravitational lensing. The method provides an improvement in fidelity over the previous ones tested in this work.
Modelling globular clusters in the TNG50 simulation: predictions from dwarfs to giant galaxies
Authors: Doppel Jessica E , Sales Laura V , Nelson Dylan , Pillepich Annalisa , Abadi Mario G , Peng Eric W , Marinacci Federico , Naiman Jill , Torrey Paul , Vogelsberger Mark , Weinberger Rainer , Hernquist Lars
Published: October 2022

We present a post-processing catalogue of globular clusters (GCs) for the 39 most massive groups and clusters in the TNG50 simulation of the IlllustrisTNG project (virial masses $M_{200} =[5\times 10^{12} \rm {\!-\!} 2 \times 10^{14}$] M⊙). We tag GC particles to all galaxies with stellar mass M* ≥ 5 × 106 M⊙, and we calibrate their masses to reproduce the observed power-law relation between GC mass and halo mass for galaxies with M200 ≥ 1011 M⊙ (corresponding to M* ∼ 109 M⊙). Here, we explore whether an extrapolation of this MGC–M200 relation to lower mass dwarfs is consistent with current observations. We find a good agreement between our predicted number and specific frequency of GCs in dwarfs with $\rm {\it M}_*=[5 \times 10^6 \rm {\!-\!} 10^9]$ M⊙ and observations. Moreover, we predict a steep decline in the GC occupation fraction for dwarfs with M* < 109 M⊙ that agrees well with current observational constraints. This declining occupation fraction is due to a combination of tidal stripping in all dwarfs plus a stochastic sampling of the GC mass function for dwarfs with M* < 107.5 M⊙. Our simulations also reproduce available constraints on the abundance of intracluster GCs in Virgo and Centaurus A. These successes provide support to the hypothesis that the MGC–M200 relation holds, albeit with more scatter, all the way down to the regime of classical dwarf spheroidals in these environments. Our GC catalogues are publicly available as part of the IllustrisTNG data release.
Evidence for strong progenitor age dependence of type Ia supernova luminosity standardization process
Authors: Lee Young-Wook , Chung Chul , Demarque Pierre , Park Seunghyun , Son Junhyuk , Kang Yijung
Published: October 2022

Supernova (SN) cosmology is based on the assumption that the width–luminosity relation (WLR) and the colour–luminosity relation (CLR) in the type Ia SN luminosity standardization would not show absolute magnitude differences with progenitor age. Unlike this expectation, recent age datings of stellar populations in host galaxies have shown significant correlations between progenitor age and Hubble residual (HR). Here, we show that this correlation originates from a strong progenitor age dependence of the zero-points of the WLR and the CLR, in the sense that SNe from younger progenitors are fainter each at given light-curve parameters x1 and c. This 4.6σ result is reminiscent of Baade’s discovery of the zero-point variation of the Cepheid period–luminosity relation with age, and, as such, causes a serious systematic bias with redshift in SN cosmology. Other host properties show substantially smaller and insignificant offsets in the WLR and CLR for the same data set. We illustrate that the differences between the high-$z$ and low-$z$ SNe in the WLR and CLR, and in HR after the standardization, are fully comparable to those between the correspondingly young and old SNe at intermediate redshift, indicating that the observed dimming of SNe with redshift may well be an artefact of overcorrection in the luminosity standardization. When this systematic bias with redshift is properly taken into account, there is little evidence left for an accelerating universe, in discordance with other probes, urging the follow-up investigations with larger samples at different redshift bins.
The high-energy probability distribution of accretion disc luminosity fluctuations
Authors: Mummery Andrew , Balbus Steven
Published: October 2022

The probability density function of accretion disc luminosity fluctuations at high observed energies (i.e. energies larger than the peak temperature scale of the disc) is derived, under the assumption that the temperature fluctuations are lognormally distributed. Thin disc theory is used throughout. While lognormal temperature fluctuations would imply that the disc’s bolometric luminosity is also lognormal, the observed Wien-like luminosity behaves very differently. For example, in contrast to a lognormal distribution, the standard deviation of the derived distribution is not linearly proportional to its mean. This means that these systems do not follow a linear rms-flux relationship. Instead they exhibit very high intrinsic variance, and undergo what amounts to a phase transition, in which the mode of the distribution (in the statistical sense) ceases to exist, even for physically reasonable values of the underlying temperature variance. The moments of this distribution are derived using asymptotic expansion techniques. A result that is important for interpreting observations is that the theory predicts that the fractional variability of these disc systems should increase as the observed frequency is increased. The derived distribution will be of practical utility in quantitatively understanding the variability of disc systems observed at energies above their peak temperature scale, including X-ray observations of tidal disruption events.
SN 2019ein: a Type Ia supernova likely originated from a sub-Chandrasekhar-mass explosion
Authors: Xi Gaobo , Wang Xiaofeng , Li Wenxiong , Mo Jun , Zhang Jujia , Liu Jialian , Chen Zhihao , Filippenko Alexei V , Zheng Weikang , Brink Thomas G , Zhang Xinghan , Sai Hanna , Ehgamberdiev Shuhrat A , Mirzaqulov Davron , Zhang Jicheng
Published: October 2022

We present extensive optical photometric and spectroscopic observations for the nearby Type Ia supernova (SN Ia) 2019ein, spanning the phases from ∼3 to ∼330 d after the explosion. This SN Ia is characterized by extremely fast expansion at early times, with initial velocities of Si ii and Ca ii being above ∼25 000–30 000 km s−1. After experiencing an unusually rapid velocity decay, the ejecta velocity dropped to ∼13 000 km s−1 around maximum light. Photometrically, SN 2019ein has a moderate post-peak decline rate (Δm15(B) = 1.35 ± 0.01 mag), while being fainter than normal SNe Ia by about 40 per cent (with $M^{\rm max}_{B} \approx -18.71 \pm 0.15$ mag). The nickel mass synthesized in the explosion is estimated to be 0.27–0.31 M⊙ from the bolometric light curve. Given such a low nickel mass and a relatively high photospheric velocity, we propose that SN 2019ein likely had a sub-Chandrasekhar-mass white dwarf (WD) progenitor, MWD ≲ 1.22 M⊙. In this case, the explosion could have been triggered by a double-detonation mechanism, for which 1D and 2D models with WD mass MWD ≈ 1 M⊙ and a helium shell of 0.01 M⊙ can reasonably produce the observed bolometric light curve and spectra. The predicted asymmetry as a result of double detonation is also favoured by the redshifted Fe ii and Ni ii lines observed in the nebular-phase spectrum. Possible diversity in origin of high velocity SNe Ia is also discussed.
Inferring binary black holes stellar progenitors with gravitational wave sources
Authors: Mastrogiovanni S , Lamberts A , Srinivasan R , Bruel T , Christensen N
Published: October 2022

With its last observing run, the LIGO, Virgo, and KAGRA collaboration has detected almost one hundred gravitational waves from compact binary coalescences. A common approach to studying the population properties of the observed binaries is to use phenomenological models to describe the spin, mass, and redshift distributions. More recently, with the aim of providing a clearer link to astrophysical processes forming the observed compact binaries coalescences, several authors have proposed to employ synthetic catalogues for population studies. In this paper, we review how to employ and interpret synthetic binary catalogues for gravitational-wave progenitors studies. We describe how to build multichannel merger rates and describe their associated probabilities focusing on stellar progenitor properties. We introduce a method to quantify the match between the phenomenological reconstruction of merger rates with synthetic catalogues. We detail the implementation of synthetic catalogues for multichannel hierarchical Bayesian inference, highlighting computational aspects and issues related to hyper-prior choice. We find that when inferring stellar progenitors’ properties from gravitational-wave observations, the relative efficiency in compact objects production should be taken into account. Finally, by simulating binary black hole detections with LIGO and Virgo sensitivity expected for the O4 observing run, we present two case studies related to the inference of the common envelope efficiency and progenitor metallicity of the binary black holes. We finally discuss how progenitors’ properties can be linked to binary black hole properties.
Stellar angular momentum can be controlled from cosmological initial conditions
Authors: Cadiou Corentin , Pontzen Andrew , Peiris Hiranya V
Published: October 2022

The angular momentum of galaxies controls the kinematics of their stars, which in turn drives observable quantities such as the apparent radius, the bulge fraction, and the alignment with other nearby structures. To show how angular momentum of galaxies is determined, we build high (35 pc) resolution numerical experiments in which we increase or decrease the angular momentum of the Lagrangian patches in the early universe. We perform cosmological zoom-in simulations of three galaxies over their histories from z = 200 to z = 2, each with five different choices for the angular momentum (15 simulations in total). Our results show that altering early universe angular momentum changes the timing and orbital parameters of mergers, which in turn changes the total stellar angular momentum within a galaxy’s virial radius in a predictable manner. Of our three galaxies, one has no large satellite at z = 2; in this case, the specific angular momentum is concentrated in the central galaxy. Our changes to the initial conditions result in its stellar angular momentum changing over 0.7 dex (from 61 to ${320}\, {\rm kpc\, km\, s}^{-1}$) at z = 2. This causes its effective radius to grow by 40 per cent, its v/σ parameter to grow by a factor of 2.6, and its bulge fraction to decrease from 0.72 to 0.57. This proof of concept illustrates how causal studies can contribute to a better understanding of the origin of galaxy scaling relations and intrinsic alignments.
Comparing simulated Milky Way satellite galaxies with observations using unsupervised clustering
Authors: Chen Li-Hsin , Hartwig Tilman , Klessen Ralf S , Glover Simon C O
Published: October 2022

We develop a new analysis method that allows us to compare multidimensional observables to a theoretical model. The method is based on unsupervised clustering algorithms which assign the observational and simulated data to clusters in high dimensionality. From the clustering result, a goodness of fit (the p-value) is determined with the Fisher–Freeman–Halton test. We first show that this approach is robust for 2D Gaussian distributions. We then apply the method to the observed MW satellites and simulated satellites from the fiducial model of our semi-analytic code a-sloth . We use the following five observables of the galaxies in the analysis: stellar mass, virial mass, heliocentric distance, mean stellar metallicity [Fe/H], and stellar metallicity dispersion σ[Fe/H]. A low p-value returned from the analysis tells us that our a-sloth fiducial model does not reproduce the mean stellar metallicity of the observed MW satellites well. We implement an ad hoc improvement to the physical model and show that the number of dark matter merger trees which have a p-value > 0.01 increases from 3 to 6. This method can be extended to data with higher dimensionality easily. We plan to further improve the physical model in a-sloth using this method to study elemental abundances of stars in the observed MW satellites.
A Gaia EDR3 search for tidal tails in disintegrating open clusters
Authors: Bhattacharya Souradeep , Rao Khushboo K , Agarwal Manan , Balan Shanmugha , Vaidya Kaushar
Published: October 2022

We carry out a search for tidal tails in a sample of open clusters with known relatively elongated morphology. We identify the member stars of these clusters from the precise astrometric and deep photometric data from Gaia Early Data Release 3 using the robust membership determination algorithm, ML-MOC. We identify 46 open clusters having a stellar corona beyond the tidal radius, 20 of which exhibit extended tails aligned with the cluster orbit direction in Galactocentric coordinates. Notably, we find NGC 6940 (at a distance of ∼1 kpc) is the furthest open cluster, exhibiting tidal tails that are ∼50 pc from its centre, while also identifying ∼40 pc long tidal tails for the nearby Pleiades. Using the minimum spanning tree length for the most massive stars relative to all cluster members, we obtain the mass segregation ratio ($\rm \lambda _{MSR}$) profiles as a function of the number of massive stars in each cluster. From these profiles, we can classify the open clusters into four classes based on the degree of mass segregation experienced by the clusters. We find that clusters in the most mass segregated classes are the oldest on average and have the flattest mass function slope. Of the 46 open clusters studied in this work, 41 exhibit some degree of mass segregation. Furthermore, we estimate the initial masses (M$\rm _{i}$) of these open clusters, finding that some of them, having M$\rm _{i}\gtrsim 10^{4} M_{\odot }$, could be the dissolving remnants of young massive clusters.
Testing source confusion and identification capability in Cherenkov telescope array data
Authors: Mestre Enrique , Torres Diego F , de Oña Wilhelmi Emma , Martí Josep
Published: October 2022

The Cherenkov Telescope Array will provide the deepest survey of the Galactic Plane performed at very-high-energy gamma-rays. Consequently, this survey will unavoidably face the challenge of source confusion, i.e. the non-unique attribution of signal to a source due to multiple overlapping sources. Among the known populations of Galactic gamma-ray sources and given their extension and number, pulsar wind nebulae (PWNe, and PWN TeV haloes) will be the most affected. We aim to probe source confusion of TeV PWNe in forthcoming CTA data. For this purpose, we performed and analysed simulations of artificially confused PWNe with CTA. As a basis for our simulations, we applied our study to TeV data collected from the H.E.S.S. Galactic Plane Survey for ten extended and two point-like firmly identified PWNe, probing various configurations of source confusion involving different projected separations, relative orientations, flux levels, and extensions among sources. Source confusion, defined here to appear when the sum of the Gaussian width of two sources is larger than the separation between their centroids, occurred in ∼30 per cent of the simulations. For this sample and 0.5° of average separation between sources, we found that CTA can likely resolve up to 60 per cent of those confused sources above 500 GeV. Finally, we also considered simulations of isolated extended sources to see how well they could be matched to a library of morphological templates. The outcome of the simulations indicates a remarkable capability (more than 95 per cent of the cases studied) to match a simulation with the correct input template in its proper orientation.
003 Juvenile idiopathic arthritis: a series of 22 cases
Authors: Yechouti C , Elouali A , Ayyad G , Rkain M , Benajiba N , Babakhoya A
Published: October 2022

Introduction

Juvenile Idiopathic Arthritis (JIA) is a group of conditions in which the first sign of the disease appears before the child's 16th birthday. The common feature is the presence of at least one arthritis of > 6 weeks’ duration with no recognized aetiology. JIA affect approximately one child in 5000 before the age of 16.

Materials and Methods

This is a retrospective study of 22 cases of juvenile idiopathic arthritis from the department of pediatrics at the Mohammed VI University Hospital in Oujda seen over a period of four years and 7 months (January 2014 to August 2018).

Results

The patients were 10 girls and 12 boys aged from 1 to 13 years. The hospital frequency of this disease was 0.49%, six clinical forms of onset were seen: 8(36%) had systemic onset JIA, 5(23%) had Oligoarticular JIA, 2(9%) had rheumatoid positive polyarticular JIA, 3(14%) had rheumatoid negative polyarticular JIA, 2(9%) had enthesitis related arthritis, and 2(9%) had undifferentiated arthritis. The diagnosis was based on clinical, biological, radiological and evolutionary elements. The biologic inflammatory syndrome was present in almost all patients in our series. Anti-nuclear antibodies were positive in two cases of polyarticular JIA and rheumatoid factor was positive in 10% of our patients. 25% had radiological features: one patient was classified as Steinbrocker stage I and the second with systemic JIA as stage III. Two other patients with oligoarticular JIA had small joint effusion and fixed flexion deformities. The treatment was with non-steroidal anti-inflammatory drugs, corticosteroids, salicylates and disease modifying anti-rheumatic drugs which were methotrexate in 47% of cases, and biotherapy in 9% of them. Outcome was favorable in most of the patients, but 31% developed complications which were: growth retardation (2), joint deformities (1), and iatrogenic complications of medical treatment (4). The variability of the outcome reflects the extreme heterogeneity of clinical forms of JIA.

Conclusion

The treatment of a child with JIA cannot be conceived outside of a multidisciplinary pediatric team. The treatment includes medication and measures to maintain a good functional state of the joints, notably rehabilitation and surgery. The biotherapies have revolutionized the therapeutic approach to JIA, with a notable effect of these new molecules, particularly anti TNF, anti-IL 1 and anti-IL 6.