bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Academic, Sociodemographic, and Program Growth Factors on Admission Offers to U.S. Graduate Education Programs in Communication Sciences and Disorders: National Trends in 2016–2020 Cycles
Authors: Watts Christopher R. , DiLollo Anthony , Zhang Yan
Published: January 2023

Purpose:

The purpose of this study was to investigate the impact of academic factors and sociodemographic factors on offers of admission to graduate education programs in communication sciences and disorders (speech-language pathology and audiology) in the United States.

Method:

A retrospective analysis of extant data from undergraduate students applying to graduate education programs through the Communication Sciences and Disorders Centralized Application Service (CSDCAS) was conducted. Descriptive, parametric, nonparametric, and multivariate hierarchical logistic modeling analyses were applied to data from 38,625 unique applicants across four consecutive application cycles from 2016 to 2020 to assess relationships between admission offers, and academic and sociodemographic factors. The academic factors included Graduate Record Examination (GRE) and grade point average (GPA; cumulative undergraduate GPA and cumulative communication sciences and disorders [CSD] GPA), and sociodemographic factors included race/ethnicity, age, disadvantaged socioeconomic status, first-generation status, and multilinguistic status.

Results:

The rate of receiving an offer of admission continuously increased from 59.4% in the 2016–2017 cycle to 75.4% in the 2019–2020 cycle (
p
< .001). The significant predictors for admission offers across all four application cycles were GPA, GRE, and applicant age. While the odds ratios of GRE and age were relatively stable, the odds ratios of GPA had a decreasing trend. Bivariate analyses showed that students who were non-White, older, socioeconomically disadvantaged, first-generation, and nonmultilingual were significantly less likely to receive offers of admission than their counterparts, but the relationships between those sociodemographic factors, except for age, and admission offers diminished when all factors were considered in the logistic regression analyses.

Conclusions:

Academic and sociodemographic factors significantly affected the likelihood of obtaining at least one offer of admission to a graduate program in CSD at different levels. While the effect sizes were variable, these findings provide evidence-based guidance for admission committees seeking to improve the inclusiveness of admission processes and the realization of greater diversity across multidimensional domains (e.g., race/ethnicity, socioeconomic status, age).
Identifying Linguistic Markers of French-Speaking Teenagers With Developmental Language Disorder: Which Tasks Matter?
Authors: Courteau Émilie , Loignon Guillaume , Steinhauer Karsten , Royle Phaedra
Published: January 2023

Purpose:

This research aimed to identify reliable tasks discriminating French-speaking adolescents with developmental language disorder (DLD) from their peers with typical language (TL) and to assess which linguistic domains represent areas of particular weakness in DLD. Unlike English, morphosyntax has not been identified as a special area of weakness when compared with lexicosemantics in French preschoolers with DLD. Since there is evidence that subject–verb number agreement is consolidated in later childhood, one might expect morphosyntax to be a particular weakness and marker of French DLD only in (pre)adolescence.

Method:

We administered 20 subtasks that assessed linguistic and phonological working memory skills of two groups: 17 adolescents clinically identified as having DLD (
M
= 14.1 years) and 20 (pre)teens with TL (
M
= 12.2 years). Using robust statistics that are less affected by outliers, we selected the most discriminating subtasks between our groups, calculated their optimal cutoff score, and derived diagnostic accuracy statistics. We combined these subtasks in a multivariable model to identify which subtasks contributed the most to the identification of DLD.

Results:

Seven subtasks were selected as discriminating between our groups, and three showed outstanding diagnostic accuracy: Recalling Sentences, a multiword task assessing lexicosemantic skills, and a subject–verb number agreement production task. When combined, we found that the latter contributed the most to our multivariable model.

Conclusion:

This study provides evidence that the most relevant markers to identify DLD in French teenagers are tasks assessing lexicosemantics and morphosyntactic domains, and that morphosyntax should be considered an important area of weakness in French-speaking teenagers with DLD.

Supplemental Material:

https://doi.org/10.23641/asha.21753932
Eliminating Racial Bias and Challenges for Black Athletes With Sports-Related Concussion: The Role of Speech-Language Pathology Clinicians and Researchers
Authors: Davis Alaina S.
Published: January 2023

Purpose:

The aim of this tutorial is to highlight racial bias and challenges for Black adult athletes' cognitive-communication disorders associated with sports-related concussion (SRC). The author discusses racial bias in SRC literature and research and cultural differences in the cognitive and communication styles of Black athletes that lead to bias. The tutorial highlights challenges placed on the Black athletes when culturally responsive practices are not used in research and clinical practice. Finally, speech-language pathology clinicians and researchers are provided with practical solutions to decrease racial barriers in SRC research and clinical practice.

Conclusion:

Challenges for Black adult athletes with SRC can be overcome when speech-language pathology clinicians and researchers increase their awareness of what causes racial health disparities, eliminate beliefs in stereotypes centered around the cognitive and communication styles of Black adults, and engage in culturally responsive practices that promote equity and inclusion.
A new method for calculation of closed‐form response of linear time‐invariant systems to periodic input signals
Authors: Safaai‐Jazi Ahmad
Published: January 2023

A new method for finding closed‐form time‐domain solutions of linear time‐invariant (LTI) systems with arbitrary periodic input signals is presented. These solutions, unlike those obtained based on the conventional Fourier‐phasor method, have a finite number of terms in one period. To implement the proposed method, the following steps are carried out: (1) For a given system, represented by a transfer function, an impulse response, a block diagram etc., the governing differential equation relating the output of the system, , to its input, , is obtained. (2) An auxiliary differential equation is formed by simply replacing with and equating the input side to alone. The auxiliary differential equation is solved for each time segment of the input signal in one period, leaving the constant coefficients associated with the homogeneous solutions as unknowns. For an nth‐order system with an input signal consisting of q segments in one period, there are such unknown coefficients. (3) Continuity of and its derivatives, at the connection points of successive segments and the periodicity conditions for the beginning and end points of the period are implemented. (4) The outcome of step 3 is a system of equations in terms of unknown coefficients described in step 2. Solving this system of equations, the solution for in one period is obtained. (5) Finally, using the linearity and differentiation properties of the system and the coefficients of the input side of the differential equation of the system, the total response, , in one period is constructed in terms of and its derivatives. For stable LTI systems, the proposed method can be used without any limitations.
The globular cluster system of the nearest Seyfert II galaxy Circinus
Authors: Obasi C. , Gómez M. , Minniti D. , Alonso-García J. , Hempel M. , Pullen J. B. , Gregg M. D. , Baravalle L. D. , Alonso M. V. , Okere B. I.
Published: January 2023

Context. The globular cluster (GC) system of Circinus galaxy has not been probed previously partly because of the location of the galaxy at −3.8° Galactic latitude, which suffers severely from interstellar extinction, stellar crowding, and Galactic foreground contamination. However, the deep near-infrared (NIR) photometry by the VISTA Variables in the Via Láctea Extended Survey (VVVX) in combination with the precise astrometry of Gaia EDR3 allow us to map GCs in this region.

Aims. Our long-term goal is to study and characterise the distributions of GCs and ultra-compact dwarfs in Circinus galaxy, which is the nearest Seyfert II galaxy. Here we conduct the first pilot search for GCs in this galaxy.

Methods. We used NIR VVVX photometry in combination with Gaia EDR3 astrometric features, such as astrometric excess noise and the ratio of the sum of the blue photometer (BP) and red photometer (RP) to the broad G passband (BRexcess), to build the first homogeneous catalogue of GCs in Circinus galaxy. A robust combination of selection criteria allows us to effectively clean interlopers from our sample.

Results We report the detection of ∼70 GC candidates in this galaxy at a 3σ confidence level. They show a bimodal colour distribution with the blue peak at (G − Ks)0 = 0.985±0.127 mag with a dispersion of 0.211±0.091 mag and the red peak at (G − Ks)0 = 1.625±0.177 mag with a dispersion of 0.482±0.114 mag. A GC specific frequency (S​N) of 1.3±0.2 was derived for the galaxy, and we estimated a total population of 120±40 GCs. Based on the projected radial distribution it appears that Circinus has a different distribution of GC candidates than MW and M 31.

Conclusions. We demonstrate that Circinus galaxy hosts a sizeable number of cluster candidates. This result is the first leap towards understanding the evolution of old stellar clusters in this galaxy.
GaiaData Release 3
Authors: Marton Gábor , Ábrahám Péter , Rimoldini Lorenzo , Audard Marc , Kun Mária , Nagy Zsófia , Kóspál Ágnes , Szabados László , Holl Berry , Gavras Panagiotis , Mowlavi Nami , Nienartowicz Krzysztof , de Fombelle Grégory Jevardat , Lecoeur-Taïbi Isabelle , Karbevska Lea , Lario Pedro Garcia , Eyer Laurent
Published: January 2023

Context.TheGaiathird Data Release (DR3) presents the first catalogue of full-sky variable young stellar object (YSO) candidates observed by theGaiaspace telescope during the initial 34 months of science operations.

Aims.Numerous types of variable stars were classified using photometric data collected byGaia. One of the new classes presented in theGaiaDR3 is the class of YSOs showing brightness variability. We analysed 79 375 sources classified as YSO candidates in order to validate their young nature and investigate the completeness and purity of the sample.

Methods.We cross-matched theGaiaDR3 YSO sample with numerous catalogues from the literature, including YSO catalogues based on optical and infrared data, as well as catalogues of extragalactic sources and Galactic variable stars. YSO catalogues were used to quantify the completeness of theGaiaDR3 YSO sample, while others were inspected to calculate the contamination.

Results.Among the 79 375 potential YSO candidates published in theGaiaDR3 variable star catalogue, the majority of these objects are distributed along the line of sight of well-known star forming regions and the Galactic midplane. We find that the upper limit of contamination is 26.7%, depending on the external catalogue used for the estimation, but find an average of ∼10% in general, while the completeness is at the percent level, taking into account that theGaiaDR3 YSO sample is based on sources that showed significant variability during the data-collection period. The number of sources in our sample that had not previously been catalogued as YSO candidates is ∼40 000 objects.
Reconstructing the extended structure of multiple sources strongly lensed by the ultra-massive elliptical galaxy SDSS J0100+1818
Authors: Bolamperti A. , Grillo C. , Cañameras R. , Suyu S. H. , Christensen L.
Published: January 2023

We study the total and baryonic mass distributions of the deflector SDSS J0100+1818 through a full strong lensing analysis. The system is composed of an ultra-massive early-type galaxy at z = 0.581, with a total stellar mass of (1.5 ± 0.3)×1012 M⊙ and a stellar velocity dispersion of (450 ± 40) km s−1, surrounded by ten multiple images of three background sources, two of which are spectroscopically confirmed at z = 1.880. We took advantage of high-resolution HST photometry and VLT/X-shooter spectroscopy to measure the positions of the multiple images and performed a strong lensing study with the software GLEE. We tested different total mass profiles for the lens and modeled the background sources first as point-like and then as extended objects. We successfully predict the positions of the observed multiple images and reconstruct over approximately 7200 HST pixels the complex surface brightness distributions of the sources. We measured the cumulative total mass profile of the lens and find a total mass value of (9.1 ± 0.1)×1012 M⊙, within the Einstein radius of approximately 42 kpc, and stellar-over-total mass fractions ranging from (49 ± 12)%, at the half-light radius (Re = 9.3 kpc) of the lens galaxy, to (10 ± 2)%, in the outer regions (R = 70 kpc). These results suggest that the baryonic mass component of SDSS J0100+1818 is very concentrated in its core and that the lens early-type galaxy (or group) is immersed in a massive dark matter halo, which allows it to act as a powerful gravitational lens, creating multiple images with exceptional angular separations. This is consistent with what has been found in other ultra-high-mass candidates at intermediate redshift. We also measured the physical sizes of the distant sources, resolving them down to a few hundred parsecs. Finally, we quantify and discuss a relevant source of systematic uncertainties on the reconstructed sizes of background galaxies, associated with the adopted lens total mass model.
A complete spectroscopic catalogue of local galaxies in the northern spring sky: Gas properties and nuclear activity in different environments
Authors: Cattorini Federico , Gavazzi Giuseppe , Boselli Alessandro , Fossati Matteo
Published: January 2023

With the aim of providing the complete demography of galaxies in the local Universe, including their nuclear properties, we present SPRING, a complete census of local galaxies limited to the spring quarter of the northern sky (10h < RA < 16h; 0° < Dec < 65°). The SPRING catalogue is a flux- and volume-limited sample (r < 17.7 mag,cz < 10 000 km s−1) of 30 597 galaxies, including the Virgo, Coma, and A1367 clusters. Images and spectra were individually examined to clear the sample from unwanted entries. To inspect possible secular and environmental dependencies of the various nuclear excitation properties (star-forming versus active nuclei), we performed a multi-dimensional analysis by dividing the total sample according to: (i) their position in the (NUV − i) versusMstardiagram, (ii) the local galaxy density, (iii) the stellar mass, (iv) the halo mass of the group to which galaxies belong, and (v) the neutral hydrogen content. We present a new calibration of the optical diameter-based H I-deficiency parameter H Idef, employing a reference sample of isolated galaxies extracted from SPRING. At intermediate distances between Virgo and Coma, we identify a ring-like structure of galaxies constituted by three large filaments, each with a length of approximately 20h−1Mpc, mostly composed of blue-cloud galaxies with stellar massesMstar ≲ 1010 M⊙. The fraction of H I-deficient galaxies within the filament (∼30%) suggests that filaments are a transitioning environment between lower- and higher-overdensity environments in terms of H I content, as we find a clear progression from field galaxies to the filament and cluster galaxies for an increasing H Idefparameter. We classify the nuclear spectra according to the four-line Baldwin-Phillips-Terlevich (BPT) and the two-line EWHαversus [NII]/Hα(WHAN) diagnostic diagrams, and investigate the variation in the fraction of active nuclei hosts with stellar mass, as well as their colours and environments. We observe that the fraction of low-ionisation nuclear emitting regions (LINERs) is a steep function of stellar mass, for example, it is consistent with zero up toMstar ≲ 109.5 M⊙and becomes ∼40% forMstar ≳ 1010.5 M⊙, whereas, forMstar ≲ 109 − 9.5 M⊙, almost the entire spectroscopic sample is constituted of galaxies with star-forming nuclei. We investigate whether the nuclear-excitation fractions depend predominantly on the stellar mass or, conversely, on the galaxy environment. In general, we observe that the mass dependence of the fraction of Seyfert nuclei is not very sensitive to the galaxy environment, whereas the fraction of star-forming nuclei is a steeper function of stellar mass in lower-density environments and in blue-cloud galaxies. We find that the fraction of LINERs depends on galaxy colour and, forMstar ≳ 109.5 − 10 M⊙, increases in galaxies belonging to the green valley.
Importance of source structure on complex organics emission
Authors: Nazari P. , Tabone B. , Rosotti G. P.
Published: January 2023

Context. The hot molecular core phase of massive star formation shows emission from complex organic molecules. However, these species are only detected toward a fraction of high-mass protostars. In particular, there is a spread of ~2 orders of magnitude in methanol emission intensity from high-mass protostars.

Aims. The goal of this work is to answer the question of whether high-mass disks can explain the lack of methanol emission from some massive protostellar systems.

Methods. We considered an envelope-only and an envelope-plus-disk model and used the code RADMC-3D to calculate the methanol emission. High and low millimeter (mm) opacity dust (representing large and small dust distributions) were considered for both models separately, and the methanol abundance was parameterized. Viscous heating was included due to the high accretion rates of these objects in the disk.

Results. In contrast with low-mass protostars, the presence of a disk does not significantly affect the temperature structure and methanol emission. The shadowing effect of the disk is not as important for high-mass objects, and the disk midplane is hot because of viscous heating, which is effective due to the high accretion rates. The methanol emission is lower for models with high mm opacity dust because the dust attenuation blocks the emission in the envelope and hides it in the disk through continuum oversubtraction, but the disk needs to be large for this to become effective. A minimum disk size of ~2000–2500 au is needed (at L = 104 L⊙) with high mm opacity dust for drop of a factor of about one order of magnitude in the methanol emission compared with the envelope-only models with low mm opacity dust. Consistent with observations of infrared absorption lines toward high-mass protostars, we find a vertical temperature inversion, that is, higher temperatures in the disk midplane than the disk surface, at radii ≲50 au for models with L = 104 L⊙ and high mm opacity dust as long as the envelope mass is ≳550 M⊙ (Ṁ = 3.6 × 10−3 M⊙ yr−1).

Conclusions. The large observed scatter in methanol emission from massive protostars can be mostly explained toward lower-luminosity objects (~103 L⊙) with the envelope-plus-disk models including low and high mm opacity dust. The methanol emission variation toward sources with high luminosities (≳104 L⊙) cannot be explained by models with or without a disk with a relatively high gas-phase abundance of methanol. However, the luminosity-to-mass ratios of these objects suggest that they might be associated with hypercompact or ultracompact HII regions. Therefore, the low methanol emission toward the high-luminosity sources can be explained by them hosting an HII region in which methanol is absent.
Tidal perturbations and eclipse mapping in the pulsations in the hierarchical triple system U Gru
Authors: Johnston C. , Tkachenko A. , Van Reeth T. , Bowman D. M. , Pavlovski K. , Sana H. , Sekaran S.
Published: January 2023

Context. Unambiguous examples of the influence of tides on self-excited, free stellar pulsations have recently been observationally detected in space-based photometric data.

Aims. We aim to investigate U Gru and contextualise it within the growing class of tidally influenced pulsators. An initial analysis of U Gru revealed frequencies spaced by the orbital frequency that are difficult to explain by currently proposed tidal mechanisms.

Methods. We reinvestigate the TESS photometry for U Gru alongside new UVES spectroscopy. We analyse the UVES spectroscopy with least-squares deconvolution and spectral disentangling techniques, and perform an atmospheric analysis. We remove the binary signature from the light curve using an effective model in order to investigate the pulsation signal in the residuals. We track the amplitudes and phases of the residual pulsations as a function of the orbital period to reveal their tidal influence.

Results. We establish that U Gru is likely a hierarchical triple system. We identify a single p-mode oscillation that exhibits amplitude and phase variation over the binary orbit. We propose a toy model to demonstrate that the series of frequencies separated by the orbital frequency can be reproduced by eclipse mapping. We find no evidence of modulation to the other independent oscillation modes.

Conclusions. We demonstrate that U Gru hosts at least one tidally perturbed pulsation. Additionally, we argue that eclipse mapping of the dominant, tidally perturbed mode can produce the series of frequencies separated by the observed orbital frequency. Our simulations show that the effects of eclipse mapping are mode dependent, and are not expected to produce an observable signature for all pulsation modes in an eclipsing binary.
Massive pre-main-sequence stars in M17
Authors: Backs F. , Poorta J. , Rab Ch. , Derkink A. R. , de Koter A. , Kaper L. , Ramírez-Tannus M. C. , Kamp I.
Published: January 2023

Context.The young massive-star-forming region M17 contains optically visible massive pre-main-sequence stars that are surrounded by circumstellar disks. Such disks are expected to disappear when these stars enter the main sequence. The physical and dynamical structure of these remnant disks are poorly constrained, especially the inner regions where accretion, photo-evaporation, and companion formation and migration may be ongoing.

Aims.We aim to constrain the physical properties of the inner parts of the circumstellar disks of massive young stellar objects B243 (6M⊙) and B331 (12M⊙), two systems for which the central star has been detected and characterized previously despite strong dust extinction.

Methods.Two-dimensional radiation thermo-chemical modelling with PRODIMOof double-peaked hydrogen lines of the Paschen and Brackett series observed with X-shooter was used to probe the properties of the inner disk of the target sources. The model was modified to treat these lines. Additionally, the dust structure was studied by fitting the optical and near-infrared spectral energy distribution.

Results.B243 features a hot gaseous inner disk with dust at the sublimation radius at ~3 AU. The disk appears truncated at roughly 6.5 AU; a cool outer disk of gas and dust may be present, but it cannot be detected with our data. B331 also has a hot gaseous inner disk. A gap separates the inner disk from a colder dusty outer disk starting at up to ~100 AU. In both sources the inner disk extends to almost the stellar surface. Chemistry is essential for the ionization of hydrogen in these disks.

Conclusions.The lack of a gap between the central objects and these disks suggests that they accrete through boundary-layer accretion. This would exclude the stars having a strong magnetic field. Their structures suggest that both disks are transitional in nature, that is to say they are in the process of being cleared, either through boundary-layer accretion, photo-evaporation, or through companion activity.
Physical conditions for dust grain alignment in Class 0 protostellar cores
Authors: Le Gouellec V. J. M. , Maury A. J. , Hull C. L. H.
Published: January 2023

Context. High angular resolution observations of Class 0 protostars have produced detailed maps of the polarized dust emission in the envelopes of these young embedded objects. Interestingly, the improved sensitivity brought by ALMA has revealed wide dynamic ranges of polarization fractions, with specific locations harboring surprisingly large amounts of polarized dust emission.

Aims. Our aim is to characterize the grain alignment conditions and dust properties responsible for the observed polarized dust emission in the inner envelopes (≤1000 au) of Class 0 protostars.

Methods. We analyzed the polarized dust emission maps obtained with ALMA and compared them to molecular line emission maps of specific molecular tracers, mainly C2H, which allowed us to probe one of the key components in dust grain alignment theories: the irradiation field.

Results. We show that C2H peaks toward outflow cavity walls, where the polarized dust emission is also enhanced. Our analysis provides a tentative correlation between the morphology of the polarized intensity and C2H emission, suggesting that the radiation field impinging on the cavity walls favors both the grain alignment and the warm carbon chain chemistry in these regions. We propose that shocks happening along outflow cavity walls could potentially represent an additional source of photons contributing to dust grain alignment. However, some parts of the cores, such as the equatorial planes, exhibit enhanced polarized flux, although no radiation driven chemistry is observed, for example where radiative torques are theoretically not efficient enough. This suggests that additional physical conditions, such as source geometry and dust grain evolution, may play a role in grain alignment.

Conclusions. Comparing chemical processes with grain alignment physics opens a promising avenue to develop our understanding of the dust grain evolution (i.e., their origin, growth, and structure) in the interior of Class 0 protostars. The source geometry and evolution can represent important factors that set the environmental conditions of the inner envelope, determining whether the radiation field strength and spectrum can drive efficient dust grain alignment via radiative torques.
Misalignment of the outer disk of DK Tau and a first look at its magnetic field using spectropolarimetry
Authors: Nelissen M. , McGinnis P. , Folsom C. P. , Ray T. , Vidotto A. A. , Alecian E. , Bouvier J. , Morin J. , Donati J.-F. , Devaraj R.
Published: January 2023

Context. Misalignments between a forming star’s rotation axis and its outer disk axis, although not predicted by standard theories of stellar formation, have been observed in several classical T Tauri stars (cTTs). The low-mass cTTs DK Tau is suspected of being among them. In addition, it is an excellent subject to investigate the interaction between stellar magnetic fields and material accreting from the circumstellar disk, as it presents clear signatures of accretion.

Aims. The goal of this paper is to study DK Tau’s average line-of-sight magnetic field in both photospheric absorption lines and emission lines linked to accretion, using spectropolarimetric observations, as well as to examine inconsistencies regarding its rotation axis.

Methods. We used data collected with the ESPaDOnS spectropolarimeter, at the Canada-France-Hawaii Telescope, and the NARVAL spectropolarimeter, at the Télescope Bernard Lyot, probing two distinct epochs (December 2010 to January 2011 and November to December 2012), each set spanning a few stellar rotation cycles. We first determined the stellar parameters of DK Tau, such as effective temperature and vsini. Next, we removed the effect of veiling from the spectra, then obtained least-squares deconvolution (LSD) profiles of the photospheric absorption lines for each observation, before determining the average line-of-sight magnetic field from them. We also investigated accretion-powered emission lines, namely the 587.6 nm HeI line and the CaII infrared triplet (at 849.8 nm, 854.2 nm and 866.2 nm), as tracers of the magnetic fields present in the accretion shocks.

Results. We find that DK Tau experiences accretion onto a magnetic pole at an angle of ∼30° from the pole of its rotation axis, with a positive field at the base of the accretion funnels. In 2010 we find a magnetic field of up to 0.95 kG (from the CaII infrared triplet) and 1.77 kG (from the HeI line) and in 2012 we find up to 1.15 kG (from the CaII infrared triplet) and 1.99 kG (from the HeI line). Additionally, using our derived values of period, vsini and stellar radius, we find a value of 58° (+18)(−11) for the inclination of the stellar rotation axis, which is significantly different from the outer disk axis inclination of 21° given in the literature.

Conclusion. We find that DK Tau’s outer disk axis is likely misaligned compared to its rotation axis by 37°.
Non-local thermodynamic equilibrium analysis of the methylidyne radical molecular lines in metal-poor stellar atmospheres
Authors: Popa S. A. , Hoppe R. , Bergemann M. , Hansen C. J. , Plez B. , Beers T. C.
Published: January 2023

Aims. An analysis of the methylidyne (CH) radical in non-local thermodynamic equilibrium (NLTE) is performed for the physical conditions of cool stellar atmospheres typical of red giants (log ɡ = 2.0, Teff = 4500 K) and the Sun. The aim of the present work is to explore whether the G band of the CH molecule, which is commonly used in abundance diagnostics of carbon-enhanced metal-poor stars, is sensitive to NLTE effects.

Methods. LTE and NLTE theoretical spectra were computed with the MULTI code. We used one-dimensional (1D) LTE hydrostatic MARCS model atmospheres with parameters representing eleven red giant stars with metallicities ranging from [Fe/H] = −4.0 to [Fe/H] = 0.0 and carbon-to-iron ratios of [C/Fe] = 0.0, +0.7, +1.5, and +3.0. The CH molecule model was represented by 1981 energy levels, 18 377 radiative bound-bound transitions, and 932 photo-dissociation reactions. The rates due to transitions caused by collisions with free electrons and hydrogen atoms were computed using classical recipes.

Results. Our calculations suggest that NLTE effects in the statistical equilibrium of the CH molecule are significant and cannot be neglected for precision spectroscopic analysis of C abundances. The NLTE effects are mostly driven by radiative over-dissociation, owing to the very low dissociation threshold of the molecule and significant resonances in the photo-dissociation cross-sections. The NLTE effects in the G band increase with decreasing metallicity. When comparing the C abundances determined from the CH G band in LTE and in NLTE, we show that the C abundances are always under-estimated if LTE is assumed. The NLTE corrections to C abundance inferred from the CH feature range from +0.04 dex for the Sun to +0.21 dex for a red giant with metallicity [Fe/H] = −4.0.

Conclusions. Departures from the LTE assumption in the CH molecule are non-negligible, and NLTE effects have to be taken into account in the diagnostic spectroscopy based on the CH lines. We show here that the NLTE effects in the optical CH lines are non-negligible for the Sun and red giant stars, but further calculations are warranted to investigate the effects in other regimes of stellar parameters.
Effects of rotation on the spectroscopic observables of massive stars
Authors: Abdul-Masih M.
Published: January 2023

Context. Rotation is ubiquitous among massive stars and with rotation comes a deformation to the surface geometry. This, in turn leads to alterations in the distribution of parameters across the surface including surface gravity, temperature, and ionization balance of the surface elements. These 3D effects are often neglected when analyzing the spectra of rapidly rotating massive stars.

Aims. We aim to determine whether neglecting the 3D deformations resulting from rapid rotation has an impact on the final spectroscopic observables, and if so to what degree.

Methods. Using the SPAMMS code, we generated a grid of synthetic spectra that account for the 3D geometry of rapidly rotating stars and compared them to synthetic spectra generated assuming spherical geometry. Using equivalent width (EW) and full width half maximum (FWHM) measurements as proxies, we determined how the measured temperature, helium abundance, and projected rotation rates of individual lines in different ionization states vary with rotation rates and inclinations.

Results. We find that the 3D geometry can have a significant impact on the measured parameters. We show that the temperature is highly dependent on both the rotation rate and the inclination, and that the same system viewed at different inclinations can have measured temperatures that differ by as much as 10%. We also find that the helium abundance can be underestimated by as much as 60% and that lines in different ionization states can have measurable differences in rotation rates. We demonstrate that these differences in rotation rates can be seen in observed data and show that this could allow for an inclination-independent measurement of the rotational velocity.

Conclusions. Our results indicate that neglecting the 3D effects of rotation can cause significant biases in the measured spectroscopic parameters and that in many cases, the measured values are more than 3σ away from the true values.
History of the iron furnace using the physical-chemical blast furnace model
Authors: Nicolle Rémy
Published: January 2023

The physical–chemical blast furnace model first built by Michard and Rist has proven to be a very efficient tool to predict and drive the present blast furnaces. It mostly describes the iron blast furnace as a counter current gas-solids dual heat and oxygen exchanger. The onset of coke gasification (orelse of iron oxide direct reduction), leads to a two-zones exchange model. This theory is used to look back at the operation of the earlier and smaller iron furnaces such as the early XIXth century charcoal blast furnace or the much older low shaft furnaces. It shows the interest of using physical-chemical models to better understand the operation of past production tools.
L’équipe mobile d’urgence pédopsychiatrique : un passeur d’espace-temps
Authors: Priol Anne-Clémence , Ferley Sébastien , Chauliac Olivier , Fagon Henry , Le Gouestre Diane , Dubois Vincent-Henri , Thepaut Mathieu , Guillemot Paul , Tordjman Sylvie
Published: January 2023

Cet article rend compte de plus de 10 ans de fonctionnement d’une équipe mobile d’urgence pédopsychiatrique, l’EMUP – équipe mobile basée aux urgences pédiatriques qui y accueille en blouse blanche les jeunes et leurs familles, mais sort des urgences dès le 2e rendez-vous en se déplaçant sans blouse blanche au domicile ou au CMP – et permet d’illustrer ainsi l’importance du passage, accompagné par cette équipe mobile, de l’espace-temps de l’urgence à l’espace-temps du soin et de l’élaboration psychiques. Le dispositif TEARS (dispositif Téléphonique d’évaluation chez les Enfants et Adolescents du Risque Suicidaire sur une durée d’un an après la crise suicidaire) a pour objectif de prolonger précisément la continuité de ce travail psychique qui s’inscrit dans une nouvelle temporalité. Le dispositif TEARS a été établi suite à une étude longitudinale d’une année des effets de l’EMUP sur le risque suicidaire et les tentatives de suicide chez les préadolescents/adolescents de moins de 16 ans. Cette recherche met en évidence l’importance de l’environnement familial dans la prise en charge des crises suicidaires avec une sévérité d’autant plus élevée des idéations suicidaires chez le jeune que l’attachement aux figures parentales est insécure et le fonctionnement familial chaotique, et un risque suicidaire d’autant plus faible que l’alliance thérapeutique a pu se construire avec le père et la mère. C’est dire l’importance de se déplacer à domicile et d’aller ainsi vers les membres de la famille qu’il serait difficile de rencontrer ailleurs, comme cela peut être le cas des pères. Le changement d’espace-temps, renforcé par le changement d’environnement social (changement de binômes), permet d’accéder à différentes représentations en fonction de l’environnement spatial (selon le lieu), temporel (selon la temporalité convoquée) et relationnel (selon la configuration professionnelle et familiale des entretiens). Les changements d’environnement spatial, temporel et relationnel entraînent un changement de perspectives, condition nécessaire au processus de changement. L’équipe mobile assure ainsi auprès du jeune, de ses parents, et de façon plus générale sa famille, une fonction majeure de passeur d’espace-temps (de l’espace-temps de l’urgence à l’espace-temps du soin et de l’élaboration psychiques) qui permet de les accompagner vers le changement (d’une représentation de soi unique et figée à une pluralité et mobilisation des représentations).
Aminotetrazole Synthesis from Secondary Amides by C–C Bond Nitrogenation
Authors: Jiao Ning , Zhang Cheng , Liu Jianzhong , Cheng Zengrui , Li Junhua , Song Song
Published: January 2023

The development of novel methods for the preparation of aminotetrazoles is of long-standing interest to chemists due to the great importance of these compounds in chemistry and biology. Here, we report an efficient method for the preparation of aminotetrazoles from secondary amides by selective C–C bond cleavage. Compared with the conventional laborious and cumbersome approaches to aminotetrazoles, this chemistry provides a highly efficient nitrogenation strategy, with the installation of four nitrogen atoms into a secondary amide in one step.
Assessment of Knowledge and Self-Awareness about Temporomandibular Joint Disorders among Dental Students
Authors: Najmuddin Mohammed , Shabi Afnan Y. , Alqadi Amna M. , Moafa Reem N. , Abdul Khader Saheb Safeena , Attafi Maisah A. , Khormi Fatimah B. , Alqadi Aziza M. , Bokamani Haifa F. , Hakami Abdullah J.
Published: January 2023

Objectives This Study Aimed To Find The Relationship Between Lack Of Knowledge And Self-Awareness About Temporomandibular Disorders (Tmds) And Their Signs And Symptoms Among Dental Students Of College Of Dentistry, Jazan University, Jazan, KSA.

Materials and Methods A self-administered structured questionnaire was used to assess the demographic variables, information regarding self-awareness and knowledge about TMDs among dental students. The data obtained were subjected to statistical analysis using the IBM SPSS version 20.0 software.

Statistical Analysis The data obtained were subjected to statistical analysis using the IBM SPSS version 20.0 software. Descriptive statistics, that is, frequencies and percentages were computed. The comparative analysis was done using Chi-square statistical analysis.

Results Out of 406 participants, 44.08% were male and 55.91% were female. Also, 329 were undergraduate students and 77 were interns. Almost a similar percentage of undergraduates and interns were suffering with trismus, articular sounds, pain, and arthralgia. Interns had more incidence of injuries of the head and neck, and had undergone orthodontic treatment, with a significant difference statistically (p < 0.05). A significant relation (p < 0.05) was observed between responses, with interns having better knowledge regarding investigations and treatment interventions.

Conclusion A direct relationship exists between the level of knowledge about temporomandibular joint (TMJ) and TMDs and self-awareness of its signs and symptoms. A thorough knowledge is required among the students to investigate, diagnose, and treat TMDs at early stages.
Polymorphic Variants across Population of the Growth Hormone Receptor with Mandible Prognathism: A Systematic Review
Authors: Sadputranto Seto A. , Maskoen Ani M. , Laviana Avi , Sjamsudin Endang
Published: January 2023

Genetic influences are critical for determining mandibular protrusion in class IIImalocclusion cases, and growth hormone receptors (GHRs) are thought to have an essential impact on craniofacial bone growth. This review aimed to assess the association between GHR gene polymorphism variants and mandibular morphology. Studies were extensively searched using PubMed and Google Scholar until December 2020. The study design according to PECOS was: P, class III malocclusion; E, GHR polymorphism; no polymorphism in C, GHR; O, linear dimensional changes in maxillary and mandibular measurements; and S, cross-sectional and case-control studies. Selected studies were of acceptable methodological quality on a 10-point scale. A preliminary search identified 107 studies; after excluding duplicate abstracts, 63 studies were screened. Nine studies were subsequently included in the systematic review. Conclusion Polymorphic variants at rs6180, rs6182, and rs6184 in the GHR gene were associated with condylion-gonion measures in Asians and Turks but not in Colombians and Egyptians.
Do personal values and motivation affect women’s solo travel intentions in Taiwan?
Authors: Teng Yi-Man , Wu Kun-Shan , Lee Ying-Chieh
Published: January 2023

Female solo travel is experiencing a global increase and specifically, gaining popularity in Asia. This study explores how personal values and female solo travel motivation affect travel behavior. Using a sample comprising 381 single females in Taiwan, partial least squares structural equation modeling was utilized to investigate the hypotheses. The results revealed Hypothesis 1 and Hypothesis 3 are supported, which verifies personal internal values significantly affect female solo travel motivation, and are identified as significant factors influencing female solo travel intention. Additionally, Hypothesis 5 is partially support, indicating the female solo travel motivations of escape/relaxation, relationship, and self-actualization contribute to the formation of positive female solo travel intention. As Hypothesis 2 and Hypothesis 4 are unsupported, external values have no impact on female solo travel motivation or any significant effect on female solo travel intention. This research adds to the vast gap in tourism literature by identifying the personal values and motivations of female solo travel, and benefits the development of the female solo travel market.
Direct hydrogen quantification in high-pressure metal hydrides
Authors: Meier Thomas , Laniel Dominique , Trybel Florian
Published: January 2023

High-pressure metal hydride (MH) research evolved into a thriving field within condensed matter physics following the realization of metallic compounds showing phonon mediated near room-temperature superconductivity. However, severe limitations in determining the chemical formula of the reaction products, especially with regards to their hydrogen content, impedes a deep understanding of the synthesized phases and can lead to significantly erroneous conclusions. Here, we present a way to directly access the hydrogen content of MH solids synthesized at high pressures in (laser-heated) diamond anvil cells using nuclear magnetic resonance spectroscopy. We show that this method can be used to investigate MH compounds with a wide range of hydrogen content, from MHx with x = 0.15 (CuH0.15) to x ≲ 6.4 (H6±0.4S5).
Atomic-displacement threshold energies and defect generation in irradiated β-Ga2O3: A first-principles investigation
Authors: Tuttle Blair R. , Karom Nathaniel J. , O’Hara Andrew , Schrimpf Ronald D. , Pantelides Sokrates T.
Published: January 2023

Gallium oxide is an emerging wide-bandgap semiconductor with promise for applications in space systems that may be exposed to energetic particles. We use molecular dynamics simulations, based on first principles density-functional methods, to determine the nature and stability of the defects generated by atoms knocked-out by particle irradiation at near threshold energies (found to be 28±1eV for Ga and 14±1eV for O). For Ga atoms, several types of low energy knock-out events result in defect complexes, but the final structures depend critically on the initial displacement direction. In contrast, a vacancy plus a peroxide linkage occurs in all types of low energy knock-out events of O atoms. Based on energy-barrier calculations, there is a low (high) probability for Ga (O) defect recombination. The electronic structure of residual, relaxed defects generated by Ga knock-outs reveals defect levels near the band edges.
Learning pair potentials using differentiable simulations
Authors: Wang Wujie , Wu Zhenghao , Dietschreit Johannes C. B. , Gómez-Bombarelli Rafael
Published: January 2023

Learning pair interactions from experimental or simulation data is of great interest for molecular simulations. We propose a general stochastic method for learning pair interactions from data using differentiable simulations (DiffSim). DiffSim defines a loss function based on structural observables, such as the radial distribution function, through molecular dynamics (MD) simulations. The interaction potentials are then learned directly by stochastic gradient descent, using backpropagation to calculate the gradient of the structural loss metric with respect to the interaction potential through the MD simulation. This gradient-based method is flexible and can be configured to simulate and optimize multiple systems simultaneously. For example, it is possible to simultaneously learn potentials for different temperatures or for different compositions. We demonstrate the approach by recovering simple pair potentials, such as Lennard-Jones systems, from radial distribution functions. We find that DiffSim can be used to probe a wider functional space of pair potentials compared with traditional methods like iterative Boltzmann inversion. We show that our methods can be used to simultaneously fit potentials for simulations at different compositions and temperatures to improve the transferability of the learned potentials.
Observation of double layer formation in low-temperature E × B plasma based negative ion sources
Authors: Shah Miral , Chaudhury Bhaskar , Bandyopadhyay Mainak , Chakraborty Arun
Published: January 2023

In this paper, formation of a double layer (DL) is studied in the background plasma (considering only electrons and ions) in the presence of a magnetic field in the context of the Rf operated beam source in India for negative ion research negative ion source by using 2D-3V particle-in-cell Monte Carlo collision kinetic simulations. A rectangular geometry to model the source, expansion, and magnetic filter regions in the negative ion source is considered in the XY plane. A Gaussian shaped magnetic field is applied in the Z-direction (perpendicular to the simulation plane), and a bias voltage is applied on the extraction boundary. Our simulations show the presence of instabilities as reported in the literature. We confirm the formation of a weak DL in the magnetic filter region under some specific combinations of the magnetic field and bias voltage. Initiation of DL leads to ion acceleration in the magnetic filter region. Split in ion velocities is also visible in the phase space plots due to the presence of free and trapped ions in the DL region. Our study highlights the effect of DL on plasma transport, which should be taken into account when interpreting the experimental observations associated with E × B plasma based negative ion sources.