bluuebunny/crossref_metadata_2025 huggingface dataset:
A Search for Faint Resolved Galaxies Beyond the Milky Way in DES Year 6: A New Faint, Diffuse Dwarf Satellite of NGC 55
Authors: McNanna M. , Bechtol K. , Mau S. , Nadler E. O. , Medoff J. , Drlica-Wagner A. , Cerny W. , Crnojević D. , Mutlu-Pakdıl B. , Vivas A. K. , Pace A. B. , Carlin J. L. , Collins M. L. M. , Ferguson P. S. , Martínez-Delgado D. , Martínez-Vázquez C. E. , Noel N. E. D. , Riley A. H. , Sand D. J. , Smercina A. , Tollerud E. , Wechsler R. H. , Abbott T. M. C. , Aguena M. , Alves O. , Bacon D. , Bom C. R. , Brooks D. , Burke D. L. , Carballo-Bello J. A. , Carnero Rosell A. , Carretero J. , da Costa L. N. , Davis T. M. , De Vicente J. , Diehl H. T. , Doel P. , Ferrero I. , Frieman J. , Giannini G. , Gruen D. , Gutierrez G. , Gruendl R. A. , Hinton S. R. , Hollowood D. L. , Honscheid K. , James D. J. , Kuehn K. , Marshall J. L. , Mena-Fernández J. , Miquel R. , Pereira M. E. S. , Pieres A. , Plazas Malagón A. A. , Sakowska J. D. , Sanchez E. , Sanchez Cid D. , Santiago B. , Sevilla-Noarbe I. , Smith M. , Stringfellow G. S. , Suchyta E. , Swanson M. E. C. , Tarle G. , Weaverdyck N. , Wiseman P. ,   DES & DELVE Collaboration
Published: January 2024

We report results from a systematic wide-area search for faint dwarf galaxies at heliocentric distances from 0.3 to 2 Mpc using the full 6 yr of data from the Dark Energy Survey (DES). Unlike previous searches over the DES data, this search specifically targeted a field population of faint galaxies located beyond the Milky Way virial radius. We derive our detection efficiency for faint, resolved dwarf galaxies in the Local Volume with a set of synthetic galaxies and expect our search to be complete to M

V
∼ (−7, −10) mag for galaxies at D = (0.3, 2.0) Mpc. We find no new field dwarfs in the DES footprint, but we report the discovery of one high-significance candidate dwarf galaxy at a distance of

2.2

−
0.12

+
0.05

Mpc

, a potential satellite of the Local Volume galaxy NGC 55, separated by 47′ (physical separation as small as 30 kpc). We estimate this dwarf galaxy to have an absolute V-band magnitude of

−

8.0

−
0.3

+
0.5

mag

and an azimuthally averaged physical half-light radius of

2.2

−
0.4

+
0.5

kpc

, making this one of the lowest surface brightness galaxies ever found with

μ
=
32.3

mag

arcsec

−
2

. This is the largest, most diffuse galaxy known at this luminosity, suggesting possible tidal interactions with its host.
Brightest Cluster Galaxy Formation in the z = 4.3 Protocluster SPT 2349-56: Discovery of a Radio-loud Active Galactic Nucleus
Authors: Chapman Scott C. , Hill Ryley , Aravena Manuel , Archipley Melanie , Babul Arif , Burgoyne James , Canning Rebecca E. A. , Deane Roger P. , De Breuck Carlos , Gonzalez Anthony H. , Hayward Christopher C. , Kim Seon Woo , Malkan Matt , Marrone Dan P. , McIntyre Vincent , Murphy Eric , Pass Emily , Perry Ryan W. , Phadke Kedar A. , Rennehan Douglas , Reuter Cassie , Rotermund Kaja M. , Scott Douglas , Seymour Nick , Solimano Manuel , Spilker Justin , Stark Anthony A. , Sulzenauer Nikolaus , Tothill Nick , Vieira Joaquin D. , Vizgan David , Wang George , Weiss Axel
Published: January 2024

We have observed the z = 4.3 protocluster SPT2349−56 with the Australia Telescope Compact Array (ATCA) with the aim of detecting radio-loud active galactic nuclei (AGNs) among the ∼30 submillimeter (submm) galaxies (SMGs) identified in the structure. We detect the central complex of submm sources at 2.2 GHz with a luminosity of L
2.2 = (4.42 ± 0.56) × 1025 W Hz−1. MeerKAT and the Australian Square Kilometre Array Pathfinder also detect the source at 816 MHz and 888 MHz, respectively, constraining the radio spectral index to α = −1.45 ± 0.16, implying L
1.4,rest = (2.2 ± 0.2) × 1026 W Hz−1. The radio observations do not have sufficient spatial resolution to uniquely identify one of the three Atacama Large Millimeter/submillimeter Array (ALMA) galaxies as the AGN, however the ALMA source properties themselves suggest a likely host. This radio luminosity is ∼100× higher than expected from star formation, assuming the usual far-infrared–radio correlation, indicating an AGN driven by a forming brightest cluster galaxy. None of the SMGs in SPT2349−56 show signs of AGNs in any other diagnostics available to us, highlighting the radio continuum as a powerful probe of obscured AGNs. We compare these results to field samples of radio sources and SMGs, along with the 22 gravitationally lensed SPT-SMGs also observed in the ATCA program, as well as powerful radio galaxies at high redshifts. The (3.3 ± 0.7) × 1038 W of power from the radio-loud AGN sustained over 100 Myr is comparable to the binding energy of the gas mass of the central halo, and similar to the instantaneous energy injection from supernova feedback from the SMGs in the core region. The SPT2349−56 radio-loud AGNs may be providing strong feedback on a nascent intracluster medium.
Magnetic Fields of the Starless Core L 1512
Authors: Lin Sheng-Jun , Lai Shih-Ping , Pattle Kate , Berry David , Clemens Dan P. , Pagani Laurent , Ward-Thompson Derek , Thieme Travis J. , Ching Tao-Chung
Published: January 2024

We present JCMT POL-2 850 μm dust polarization observations and Mimir H-band stellar polarization observations toward the starless core L 1512. We detect the highly ordered core-scale magnetic field traced by the POL-2 data, of which the field orientation is consistent with the parsec-scale magnetic fields traced by Planck data, suggesting the large-scale fields thread from the low-density region to the dense core region in this cloud. The surrounding magnetic field traced by the Mimir data shows a wider variation in the field orientation, suggesting there could be a transition of magnetic field morphology at the envelope-scale. L 1512 was suggested to be presumably older than 1.4 Myr in a previous study via time-dependent chemical analysis, hinting that the magnetic field could be strong enough to slow the collapse of L 1512. In this study, we use the Davis–Chandrasekhar–Fermi method to derive a plane-of-sky magnetic field strength (B
pos) of 18 ± 7 μG and an observed mass-to-flux ratio (λ
obs) of 3.5 ± 2.4, suggesting that L 1512 is magnetically supercritical. However, the absence of significant infall motion and the presence of an oscillating envelope are inconsistent with the magnetically supercritical condition. Using a virial analysis, we suggest the presence of a hitherto hidden line-of-sight magnetic field strength of ∼27 μG with a mass-to-flux ratio (λ
tot) of ∼1.6, in which case both magnetic and kinetic pressures are important in supporting the L 1512 core. On the other hand, L 1512 may have just reached supercriticality and will collapse at any time.
Testing the Polarization of Gravitational-wave Background with the LISA-TianQin Network
Authors: Hu Yu , Wang Pan-Pan , Tan Yu-Jie , Shao Cheng-Gang
Published: January 2024

While general relativity predicts only two tensor modes for gravitational-wave (GW) polarization, general metric theories of gravity allow for up to four additional modes, including two vector and two scalar modes. Observing the polarization modes of GWs could provide a direct test of the modified gravity. The stochastic GW background (SGWB), which can be detected by space-based laser-interferometric detectors at design sensitivity, will provide an opportunity to directly measure alternative polarization. In this paper, we investigate the performance of the LISA-TianQin network for detecting alternative polarizations of stochastic backgrounds, and propose a method to separate different polarization modes. First, we generalize the small antenna approximation to compute the overlap reduction functions for the SGWB with arbitrary polarization, which is suitable for any time-delay interferometry combination. Then we analyze the detection capability of LISA-TianQin for the SGWB with different polarizations. Based on the orbital characteristics of LISA-TianQin, we propose a method to distinguish different polarization modes from their mixed data. Finally, simulation tests are performed to verify the effectiveness of the method. The results of the simulations demonstrate that LISA-TianQin, when employing our proposed method, has the ability to differentiate between various polarization modes, with a specific emphasis on the ability to distinguish between the breathing and longitudinal modes.
Atmospheric Escape From Three Terrestrial Planets in the L 98-59 System
Authors: Fromont Emeline F. , Ahlers John P. , do Amaral Laura N. R. , Barnes Rory , Gilbert Emily A. , Quintana Elisa V. , Peacock Sarah , Barclay Thomas , Youngblood Allison
Published: January 2024

A critically important process affecting the climate evolution and potential habitability of an exoplanet is atmospheric escape, in which high-energy radiation from a star drives the escape of hydrogen atoms and other light elements from a planet’s atmosphere. L 98-59 is a benchmark system for studying such atmospheric processes, with three transiting terrestrial-sized planets receiving Venus-like instellations (4–25 S
⊕) from their M3 host star. We use the VPLanet model to simulate the evolution of the L 98-59 system and the atmospheric escape of its inner three small planets, given different assumed initial water quantities. We find that, regardless of their initial water content, all three planets accumulate significant quantities of oxygen due to efficient water photolysis and hydrogen loss. All three planets also receive enough strong X-ray and extreme-ultraviolet flux to drive rapid water loss, which considerably affects their developing climates and atmospheres. Even in scenarios of low initial water content, our results suggest that the JWST will be sensitive to observations of retained oxygen on the L 98-59 planets in its future scheduled observations, with planets b and c being the most likely targets to possess an extended atmosphere. Our results constrain the atmospheric evolution of these small rocky planets, and they provide context for current and future observations of the L 98-59 system to generalize our understanding of multiterrestrial planet systems.
The Age Distribution of Stellar Orbit Space Clumps
Authors: Fürnkranz Verena , Rix Hans-Walter , Coronado Johanna , Seeburger Rhys
Published: January 2024

The orbit distribution of young stars in the Galactic disk is highly structured, from well-defined clusters to streams of stars that may be widely dispersed across the sky, but are compact in orbital action-angle space. The age distribution of such groups can constrain the timescales over which conatal groups of stars disperse into the “field.” Gaia data have proven powerful in identifying such groups in action-angle space, but the resulting member samples are often too small and have too narrow a color–magnitude diagram (CMD) coverage to allow robust age determinations. Here, we develop and illustrate a new approach that can estimate robust stellar population ages for such groups of stars. This first entails projecting the predetermined action-angle distribution into the 5D space of positions, parallaxes, and proper motions, where much larger samples of likely members can be identified over a much wider range of the CMD. It then entails isochrone fitting that accounts for: (a) widely varying distances and reddenings; (b) outliers and binaries; (c) sparsely populated main-sequence turnoffs, by incorporating the age information of the low-mass main sequence; and (d) the possible presence of an intrinsic age spread in the stellar population. When we apply this approach to 92 nearby stellar groups identified in 6D orbit space, we find that they are predominantly young (≲1 Gyr), mono-age populations. Many groups are established (known) localized clusters with possible tidal tails, while others tend to be widely dispersed and manifestly unbound. This new age-dating tool offers a stringent approach to understanding on which orbits stars form in the solar neighborhood and how quickly they disperse into the field.
Investigating Extreme Scattering Events by Volumetric Ray-tracing
Authors: Au Kelvin , Fiege Jason D. , Rogers Adam
Published: January 2024

Extreme scattering events (ESEs) are observed as dramatic (>50%) drops in flux density that occur over an extended period of weeks to months. Discrete plasma lensing structures are theorized to scatter the radio waves produced by distant sources such as pulsars, causing the signature decrease in flux density and characteristic caustic spikes in ESE light curves. While plasma lens models in the extant literature have reproduced key features of ESE light curves, they have all faced the problem of being highly overdense and overpressured relative to the surrounding interstellar medium by orders of magnitude. We model ESEs by numerically ray tracing through analytic, volumetric plasma lens models by solving the eikonal equation. Delaunay triangulation connecting the rays approximates the wave front, generating a mapping from the observer plane to the source plane to account for multiple imaging. This eikonal method of ray tracing is tested against known analytic solutions and is then applied to a three-dimensional Gaussian-distributed electron volume density lens and a filament model inspired by Grafton et al. We find convergence of our numerical results with established analytic solutions, validating our numerical method, and reproduce ESE-like light curves. Our numerical ray-tracing method lends itself well to exploring the lensing effects of volumetric turbulence as well as sheet-like lenses, which is currently in progress.
Black Hole Ultracompact X-Ray Binaries as Galactic Low-frequency Gravitational Wave Sources: The He Star Channel
Authors: Qin Ke , Xu Kun , Liu Dong-Dong , Jiang Long , Wang Bo , Chen Wen-Cong
Published: January 2024

Black hole (BH) ultracompact X-ray binaries (UCXBs) are potential Galactic low-frequency gravitational wave (GW) sources. As an alternative channel, BH UCXBs can evolve from BH+He star binaries. In this work, we perform a detailed stellar evolution model for the formation and evolution of BH UCXBs evolving from the He star channel to diagnose their detectability as low-frequency GW sources. Our calculations found that some nascent BH+He star binaries after the common-envelope (CE) phase could evolve into UCXB-LISA sources with a maximum GW frequency of ∼5 mHz, which can be detected in a distance of 10 kpc (or 100 kpc). Once BH+He star systems become UCXBs through mass transfer, they would emit X-ray luminosities of ∼1038 erg s−1, making them ideal multimessenger objects. If the initial He-star masses are ≥0.7 M
⊙, those systems are likely to experience two Roche lobe overflows, and the X-ray luminosity can reach a maximum of 3.5 × 1039 erg s−1 in the second mass-transfer stage. The initial He-star masses and initial orbital periods of progenitors of Galactic BH UCXB-LISA sources are in the range of 0.32–2.9 M
⊙ and 0.02–0.19 days, respectively. Nearly all BH+He star binaries in the above parameter space can evolve into GW sources whose chirp masses can be accurately measured. Employing a population synthesis simulation, we predict the birthrate and detection number of Galactic BH UCXB-LISA sources evolving from the He star channel are R = 2.2 × 10−6 yr−1 and 33 for an optimistic CE parameter, respectively.
FRAMEx. V. Radio Spectral Shape at Central Subparsec Region of Active Galactic Nuclei
Authors: Shuvo Onic I. , Johnson Megan C. , Secrest Nathan J. , Gliozzi Mario , Cigan Phillip J. , Fischer Travis C. , Van Der Horst Alexander J.
Published: January 2024

We present results from the Very Long Baseline Array multifrequency (1.6, 4.4, 8.6, and 22 GHz), high-sensitivity (∼25 μJy beam−1), subparsec-scale (<1 pc) observations and spectral energy distributions for a sample of 12 local active galactic nuclei (AGNs), a subset from our previous volume-complete sample with hard-X-ray (14–195 keV) luminosities above 1042 erg s−1, out to a distance of 40 Mpc. All 12 of the sources presented here were detected in the C (4.4 GHz) and X (8.6 GHz) bands, 75% in the L band (1.6 GHz), and 50% in the K band (22 GHz). Most sources showed compact, resolved/slightly resolved, central subparsec-scale radio morphology, except for a few with extended outflow-like features. A couple of sources have an additional component that may indicate the presence of a dual-core, single or double-sided jet or a more intricate feature, such as radio emission resulting from interaction with the nearby interstellar medium. The spectral slopes are mostly gigahertz-peaked or curved, with a few showing steep, flat, or inverted spectra. We found that at the subparsec scale, the gigahertz-peaked spectra belong to the low-accreting, radio-loud AGNs, with a tendency to produce strong outflows, possibly small-scale jets, and/or have a coronal origin. In contrast, flat/inverted spectra suggest compact radio emission from the central regions of highly accreting AGNs, possibly associated with radio-quiet AGNs producing winds/shocks or nuclear star formation in the vicinity of black holes.
Infrared Emission of Specific Polycyclic Aromatic Hydrocarbon Molecules: Cyanonaphthalenes
Authors: Li Kaijun , Li Aigen , Yang X. J. , Fang Taotao
Published: January 2024

The unidentified infrared emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μm are ubiquitously seen in a wide variety of astrophysical regions and commonly attributed to polycyclic aromatic hydrocarbon (PAH) molecules. However, the unambiguous identification of any individual, specific PAH molecules has proven elusive until very recently, when two isomers of cyanonapthalene, which consists of two fused benzene rings and substitutes a nitrile (–CN) group for a hydrogen atom, were discovered in the Taurus Molecular Cloud, based on their rotational transitions at radio frequencies. To facilitate the James Webb Space Telescope (JWST) to search for cyanonapthalenes in astrophysical regions, we model the vibrational excitation of cyanonapthalenes and calculate their infrared emission spectra in a number of representative astrophysical regions. The model emission spectra and intensities will allow JWST to quantitatively determine or place an upper limit on the abundances of cyanonapthalenes.
MeerKAT 1.3 GHz Observations of Supernova Remnants
Authors: Cotton W. D. , Kothes R. , Camilo F. , Chandra P. , Buchner S. , Nyamai M.
Published: January 2024

We present full Stokes MeerKAT L-band (856–1712 MHz) observations of 36 high-latitude supernova remnants (SNRs). Sensitive, high-dynamic-range images show a wealth of structure. G15.1−1.6 appears to be a H ii region rather than an SNR. G30.7−2.0 consists of three background extragalactic sources which appear to form an arc when imaged with much lower resolution. At least half of the remnants in the sample contain “blowouts” or “ears,” showing these to be a common feature. Analysis of the polarimetric data reveals details of the magnetic field structure in the emitting regions of the remnants as well as magnetized thermal plasma in front of polarized emission. The chance alignment of G327.6+14.6 with a background active galactic nucleus with very extended polarized jets allows testing for the presence of Faraday effects in the interior of the remnant. Scant evidence of Faraday rotating material is found in the interior of this remnant.
New Polarimetric Data for the Galilean Satellites: Io and Ganymede Observations and Modeling
Authors: Kiselev Nikolai , Rosenbush Vera , Leppälä Ari , Muinonen Karri , Kolokolova Ludmilla , Savushkin Aleksandr , Karpov Nikolai
Published: January 2024

New high-precision disk-integrated measurements of the polarization of Io and Ganymede in the UBVRI bands are presented. The observations were obtained using polarimeters mounted on the Crimean Astrophysical Observatory and the Peak Terskol Observatory in 2019–2023. For Io, the negative polarization branch (NPB) reaches a minimum of P
min ≈ −0.25 ± 0.02% in the V band at a phase angle of α
min = 2.°1 ± 0.°5. The inversion angle is α
inv = 26° ± 6° in the V and R bands. The NPB for Ganymede is an asymmetric curve, with P
min = −0.34 ± 0.01% at α
min = 0.°52 ± 0.°06 and α
inv = 8.°5 ± 0.°2 in the V band. Although Io and Europa have similar geometric albedos (0.63 and 0.67, respectively), their NPB shapes differ. The NPB of Ganymede (albedo of 0.43) is morphologically similar to that of Europa, although it is described by different parameter values (P
min, α
min, and α
inv). This discrepancy is likely due to the compositions of their surfaces: Europa’s with H2O ice, Io’s with sulfuric/silicate composition, and Ganymede’s with H2O ice and silicates. Numerical computations using the radiative transfer coherent backscattering method demonstrated a match to the polarimetric observations and to the geometric albedos for Ganymede with the single-scattering albedo ≈ 0.943 and mean free path length kl = 2πl/λ
eff ≈ 150, where λ
eff is the wavelength. For Io’s regolith, the single-scattering albedo was found to be ≈ 0.979 and kl ≈ 40.
Midget cave spiders (Araneae, Leptonetidae) from Jiangxi and Fujian Province, China
Authors: Liu Bin-Lu , Yao Yan-bin , Jiang Zi-Min , Xiao Yong-hong , Liu Ke-Ke
Published: January 2024

Eleven leptonetid species belonging to four genera collected in Jiangxi and Fujian Provinces, China are presented. Ten new species of midget cave spiders from southern China are diagnosed, described, and illustrated: Leptonetela dawu Yao & Liu, sp. nov., L. yuanhaoi Yao & Liu, sp. nov. and L. zuojiashanensis Yao & Liu, sp. nov. from Jiangxi; Longileptoneta guadunensis Yao & Liu, sp. nov., L. huboliao Yao & Liu, sp. nov., L. jiaxiani Yao & Liu, sp. nov., L. letuensis Yao & Liu, sp. nov., L. renzhouensis Yao & Liu, sp. nov., L. tianmenensis Yao & Liu, sp. nov., and Pararana mingxuani Yao & Liu, sp. nov. from Fujian. Furthermore, Falcileptoneta monodactyla (Yin, Wang & Wang, 1984) is recorded from Jiangxi province for the first time. Distributions records are given for all investigated species.
Les méthodes mixtes de recherche pour l’analyse de l’activité et de l’expérience en Éducation physique et en Sport
Authors: Vors Olivier , Adé David , Gal-Petitfaux Nathalie , Joing Isabelle , Andrieu Bernard
Published: January 2024

Dans les recherches actuelles en STAPS, les chercheurs recourent de plus en plus aux méthodes mixtes de recherche (MMR) pour l’étude d’un même phénomène, en articulant des données, des méthodes et des théories (Vors & Bourcier, 2022). L’objet de cet édito est de questionner, d’un point de vue épistémologique et méthodologique, la conception et les usages par les chercheurs des MMR pour l’analyse de l’activité et de l’expérience en Éducation physique (EP) et en Sport, afin d’en discuter le potentiel heuristique. Les positionnements scientifiques quant aux MMR et leurs usages s’avèrent très hétérogènes, pouvant aller d’une articulation de données qualitatives et quantitatives soutenue par un même cadre théorique, à des analyses de données hétérogènes issues d’approches scientifiques distinctes (Johnson & Onwuegbuzie, 2004). Cette hétérogénéité est une invitation à questionner notamment la congruence de données hétérogènes et leur équilibre statutaire, ou la cohérence paradigmatique entre les cadres théoriques mobilisés (e.g., Creswell, 2011). Les MMR sont utilisées pour investiguer de nombreux objets de recherche, relatifs à des terrains d’études variés tels que ceux de l’enseignement de l’EP, de l’entraînement sportif, de l’Activité Physique Adaptée, des loisirs sportifs ou de l’expertise sportive (Camerino et al. , 2014). Les travaux concernant l’analyse de l’activité ou de l’expérience défendent en particulier la fécondité du mixage de données hétérogènes (Adé et al. , 2020). Pour autant, face à la diversité des terrains, des données, des méthodes et des théories, un questionnement épistémologique semble incontournable pour clarifier les potentiels avantages et limites des MMR en STAPS. Ce numéro spécial est l’occasion, à travers différents objets et terrains issus du champ des sciences de l’intervention de poser un regard critique et constructif sur les MMR afin d’envisager des perspectives ou des spécificités quant à leurs conceptions et usages en STAPS.
L’importation de méthodes non-supervisées en fouille de données dans le programme de recherche empirique et technologique du cours d’action : Apports et réflexions critiques
Authors: Ganachaud Clément , Seifert Ludovic , Adé David
Published: January 2024

Actuellement, les méthodes mixtes de recherche suscitent un intérêt croissant dans le domaine des sciences du sport. À ce jour, des réflexions épistémologiques et paradigmatiques ont été engagées lorsqu’il s’agit d’articuler des méthodes, outils et/ou données hétérogènes dans ce type de recherche. Cet article s’inscrit dans cette veine. Il propose une réflexion critique sur des études conduites dans le cadre du programme de recherche empirique et technologique du cours d’action (PRETCA) ayant eu recours à la fouille de données pour mettre en forme des données phénoménologiques à des fins de présentation des résultats de recherche. Cette réflexion est l’occasion de mettre en avant des apports et des points de questionnement sur le recours à la fouille de données, notamment lorsqu’il s’agit de conduire une analyse de classification hiérarchique non supervisée pour identifier des modes typiques d’expériences en situation de pratique sportive. Il ressort que cette importation d’outils et de méthodes de fouille de données nous semble traduire chez les chercheurs du PRETCA une volonté de sophistiquer le traitement des données et la présentation des résultats de recherche.
Appréhender les perceptions d’efficacité en coaching par l’utilisation des méthodes mixtes : le cas de la formation des entraîneurs de football
Authors: Lesellier Jérémy , Escalié Guillaume , Drolez Yoann , Legrain Pascal
Published: January 2024

L’article présente une méthodologie mixte originale pour appréhender une expérience de formation des entraîneurs de football en intégrant les perceptions d’efficacité en coaching. Le choix méthodologique répond notamment à un besoin identifié par les concepteurs de la formation fédérale d’optimiser les formations par l’identification des circonstances favorables au développement des perceptions d’efficacité. L’adoption d’une approche anthropo-psychologique d’une expérience de formation permet d’appréhender différentes dimensions de l’expérience de formation qui dépassent le caractère autorapporté de cette dernière. Cette vision holistique de la signification d’une expérience engage le recours à divers outils dont l’article présente l’articulation sur les plans théorique et méthodologique. Les résultats mettent en évidence, d’une part, l’effet du dispositif sur les perceptions d’efficacité des entraîneurs collectées par questionnaire, et d’autre part, les circonstances de formation qui en nourrissent le développement, à partir des entretiens d’autoconfrontation. Notamment, les expériences de vicariantes vécues en centre de formation sont identifiées comme une ressource majeure de développement professionnel pour les stagiaires. En discussion, le potentiel effet d’ordre issu de cette méthodologie mixte est questionné.
Evaluation of technological development of hydrogen fuel cells based on patent analysis
Authors: Moura Lawrence , González Mario , Silva Jéssica , Silva Lara , Braga Izaac , Ferreira Paula , Sampaio Priscila
Published: January 2024

Reducing greenhouse gas emissions is one of the major factors for the energy transformation to clean and renewable energy sources. In this context, hydrogen fuel cells play an important role in this transition, as they convert the energy stored in hydrogen into electrical energy, acting as a zero-emission technology. Therefore, an analysis of patents is relevant since it is a technology under development. We aim to evaluate the technological development of hydrogen fuel cells through a patent analysis from the Derwent Innovations Index to assess the technological advances between 2001 and 2020. The research strategies returned 22,165 patents and the study shows that: (ⅰ) There is a consistent number of patent applications in the period analyzed, which is a reflection of the high rates of research and development for this technology, and the number of patent applications of hydrogen fuel cells had two moments of growth—the first one was between 2001 and 2005, and the second was from 2015 to 2020; (ⅱ) Japan, China, South Korea, and the United States have the highest number of patent applications; (ⅲ) Toyota, Panasonic, Nissan, and Hyundai are the companies with the most patent applications, and the leading technology adopted is the polymer electrolyte membrane fuel cell; (ⅳ) the main knowledge areas of patents are engineering, electrochemistry, energy fuels, and chemistry; (ⅴ) most of the documents are subdivided by the international patent classification into patents for the improvement of technology (H01M8/04), patents for fuel cells using solid polymeric membranes (H01M8/10), and patents for reducing pollution, with a predominance of technologies aligned with the reduction of greenhouse gas emissions (H01M8/06); and (ⅵ) there is a prominence of deposited patents for polymer electrolyte membrane and solid oxide fuel cells.
The relationship between two kinds of structural credit migration models
Authors: Lin Yang , Liang Jin
Published: January 2024

In this paper, we presented an asymptotic relationship between the single threshold model and the model with different upgrade and downgrade thresholds for credit migration problems with fixed boundaries. By partial differential equation (PDE) techniques, we proved that the solution of the asymmetric threshold problem converges to that of a single threshold problem uniformly as one of the asymmetric thresholds approaches the other.
A novel parallel ant colony optimization algorithm for mobile robot path planning
Authors: Si Jian , Bao Xiaoguang
Published: January 2024

With the continuous development of mobile robot technology, its application fields are becoming increasingly widespread, and path planning is one of the most important topics in the field of mobile robot research. This paper focused on the study of the path planning problem for mobile robots in a complex environment based on the ant colony optimization (ACO) algorithm. In order to solve the problems of local optimum, susceptibility to deadlocks, and low search efficiency in the traditional ACO algorithm, a novel parallel ACO (PACO) algorithm was proposed. The algorithm constructed a rank-based pheromone updating method to balance exploration space and convergence speed and introduced a hybrid strategy of continuing to work and killing directly to address the problem of deadlocks. Furthermore, in order to efficiently realize the path planning in complex environments, the algorithm first found a better location for decomposing the original problem into two subproblems and then solved them using a parallel programming method-single program multiple data (SPMD)-in MATLAB. In different grid map environments, simulation experiments were carried out. The experimental results showed that on grid maps with scales of 20 $ \times $ 20, 30 $ \times $ 30, and 40 $ \times $ 40 compared to nonparallel ACO algorithms, the proposed PACO algorithm had less loss of solution accuracy but reduced the average total time by 50.71, 46.83 and 46.03%, respectively, demonstrating good solution performance.
Design and evaluation of INS/GNSS loose and tight coupling applied to launch vehicle integrated navigation
Authors: Cánepa Victor , Servidia Pablo
Published: January 2024

A satellite launcher requires accurate and reliable navigation to reach orbit safely. This challenging application includes vertical launch, flying through diverse layers of the atmosphere, discontinuous acceleration and stages separation, high terminal velocities and hostile temperature and vibration ranges. The Inertial Navigation System (INS) is typically coupled with a Global Navigation Satellite System (GNSS) receiver to achieve the desired solution quality along the complete ascent trajectory. Here, several INS/GNSS integrated navigation strategies are described and evaluated through numerical simulations. In particular, we evaluate different INS/GNSS integration using: loose coupling, tight coupling and an intermediate Kalman filter on the receiver to enhance the loosely coupled navigation solution. The main contributions are: a compensation model of tropospheric delays on the GNSS observables, a compensation of processing/communication delays on GNSS receiver outputs, covariance adaptations to consider vehicle's high dynamics, and an specific way to integrate the filtered solution and its covariance provided by the GNSS receiver. The tightly coupled integrated navigation proved to be the best choice to handle possible GNSS receiver positioning solution outages, to exploit more degrees of freedom for the compensation of GNSS observables and the possibility to make a cross validation of individual GNSS observables with INS-based information. This is specially important during the periods with a low number of satellites in view when the GNSS positioning solution can not be validated or even computed by the GNSS receiver alone. Finally, a test with hardware in the loop is provided to validate the numerical result for the selected tightly coupled INS/GNSS.
Effects of various disinfectants on surface roughness and color stability of thermoset and 3D-printed acrylic resin
Authors: Fotovat Farnoush , Abbasi Samaneh , Nikanjam Saeed , Alafchi Behnaz , Baghiat Mandana
Published: January 2024

Denture cleansers are extensively utilized to inhibit the colonization of various Candida species. Currently, additive technology in denture fabrication has become more prevalent. This study aims to assess the impact of disinfectants on the surface roughness and color stability of distinct denture bases. Disc-shaped samples (N=66) were exposed to three different disinfectants: 0.5% sodium hypochlorite, 1% hydrogen peroxide, and 2% chlorhexidine. The samples underwent evaluation via spectrophotometry and profilometry, respectively. Data analysis was conducted utilizing analysis of variance (ANOVA) (p < 0.05). Within the heat-cured group, sodium hypochlorite resulted in the most notable change in surface roughness (0.2 μm), while chlorhexidine exhibited the least impact (0.001 μm), showing a significant difference (p <0.008). The color change (ΔE) for 3D-printed samples immersed in all disinfectants was higher compared to heat-cured samples. Among the heat-cured samples, chlorhexidine induced the highest ΔE (2.76), while sodium hypochlorite resulted in the lowest (ΔE = 1.44), and this difference was statistically significant (p <0.008). Chlorhexidine caused the most significant color alteration among the solutions, while sodium hypochlorite induced the most considerable changes in surface roughness.
Prevalence and correlates of internet addiction among undergraduate health sciences students of Usmanu Danfodiyo University, Sokoto
Authors: Magaji Bello Arkilla , Abubakar Ahmad , Abubakar Wababe Mubarak , Chika Anas , Azeez Ibrahim , Tambuwal Sirajo Haliru
Published: January 2024

The internet is an essential aspect of our daily life, and its binge has resulted in internet addiction. Students are vulnerable to internet addiction, since they utilize it for academic and extracurricular objectives. Problematic internet use can predispose individuals to mental illnesses. We aim to determine the prevalence of internet addiction among undergraduate health sciences students at Usmanu Danfodiyo University in Sokoto, Nigeria. This was a cross-sectional study, using a multistage sampling technique. The Young Internet Addiction Test was used to obtain the data, which was analyzed using the Statistical Package for Social Sciences (SPSS) version 23.0 for Windows. The frequencies, percentages, means, and standard deviations were used to summarize the data. A chi-square was used to compare the categorical variables, and a p-value <0.05 was considered significant. A total of 294 students were interviewed, with a mean age and standard deviation of 24±2.9 years, and a male-to-female ratio of 2.3:1. Approximately, 42% of the students had mild internet addiction, and 13% had moderate internet addiction. A significant association was found between the severity of internet addiction and time spent on the internet per day. More than half of the students had mild to moderate internet addiction, which was associated with the time spent on the internet. Internet addiction among health sciences students is common and requires prompt intervention.
Compliance and Side effects of face mask use in medical team managing COVID-19: A cross-sectional survey in a tertiary care hospital
Authors: Mohamed Hussein Aliae A R , Khalaf Mohammad G A , Abd_Elaal Howida Khalaf , Kholief Karima M S , Abdelnaser Mariam G , Makhlouf Hoda A , Makhlouf Nahed A , Galal Islam
Published: January 2024

Introduction

The necessity of wearing personal protective equipment specially facemasks to prevent the spread of COVID-19 to healthcare workers has been emphasized in the current COVID-19 pandemic. This survey aimed to estimate the compliance and perceived side effects causing non-adherence to their use in medical personnel.

Methods

This cross-sectional survey was conducted in the period from March to June 2021including healthcare workers in a tertiary care isolation hospital in contact with COVID-19 cases. A designed online questionnaire was distributed to all teams and data were obtained with response rate 97.3%.

Results

The study included 302 participants. Adherence was recorded in 293 (97%) during shifts for mean duration of 6.84 ± 2.9 h. Nearly 53% reported changing masks during shift due mask damage, then contamination with secretions of COVID-19 or suspected patients. The causes of non- adherence were perceived dyspnea then headache in 65.3 and 17%. The most commonly reported side effects in all participants were dyspnea (87.4%), headache (42.7%), and 62.3% of the participants reported that these side effects began within 6 h after wearing the mask and 41.1% said that these side effects disappear after less than 1 h.

Conclusion

Adherence to use of protective facemask between medical teams during the COVID-19 in our hospital was very satisfactory. The main side effects were perceived dyspnea and headache and recorded after prolonged use. There is a need to follow the burden of these side effects to avoid non-adherence and to take measures to reduce hours of work shifts especially during pandemics.
Clinical, radiological varieties and diagnostic facilities of smear negative pulmonary tuberculosis in HIV uninfected patients, a retrospective analysis
Authors: Ibrahim Mohammed A , Shehta Mohammed
Published: January 2024

Context

Pulmonary tuberculosis (TB) is still one of the most common infectious diseases in the world. It is the second leading cause of death from an infectious disease worldwide, after the human immunodeficiency virus (HIV). WHO estimated TB incidence in Egypt in 2019 at 12 000.

Purpose

The aim of this study was to make a re-look at the epidemiological characteristics, clinical presentations, and radiological findings of patients with smear-negative pulmonary tuberculosis (SNPT) in non-HIV infected patients.

Methods

Retrospective analysis was performed including non-HIV patients with smear negative TB, with studying of demographics, symptoms, radiological patterns, and radiological distribution and the used diagnostic methods.

Statistical analysis

The demographic, clinical, and radiological data were gathered together, tabulated, and statistically analyzed. Data analysis was performed by Statistical Package for Social Science (SPSS – version 22).

Results

74 smear-negative TB, non-HIV, age mean 47.17 ± 12.8 SD, 72.2% were males, DM was present in (39.2%), fever in (83.3%), weight loss in (61.1%), cough in (59.7%), consolidation pattern in (63.8%), cavities in (36.1%), an apical segment of right upper lobe in (41.9%), bronchoscopic lavage with Ziehl–Neelsen stain (BAL ZN) diagnosed (52.7%) of sputum negative cases.

Conclusion

Common variables among recorded cases were male sex, middle-aged individuals, Diabetes Mellitus (DM), toxic manifestation, an involved right apical segment of the upper lobe, consolidation and cavitary patterns, and most cases were diagnosed by bronchoscopic lavage with Ziehl–Neelsen.
Role of Agnihotra in Maternal and Child Healthcare: A Narrative Review
Authors: Sanu Usharani Shyamasundar , Vernekar Sunil S.
Published: January 2024

Ayurveda, the Traditional Indian system of medicine with a philosophical background, has a holistic approach to health. Yuktivyapashraya chiktsa (rational treatment by use of drugs), Satvavjaya chikitsa (psychotherapy), and Daivavyapashraya chikitsa (celestial therapy) are the methods of treatment adopted in Ayurveda. Daivavyapashraya chikitsa includes the wearing of gems, chanting of mantras, and performances of homas (fire oblation rituals) which have great results but lack scientific documentation. Agnihotra is advised as a part of garbhasamskara therapy, but its scientific benefits are not documented. These therapies revive normal functioning of the mind, build sattva guna, and remove obstacles from rajas. Agnihotra, also known as homa therapy, yaga, yajna, or sacrifice, is one of the rituals of ancient Vedic traditions. This study aims to review the earlier studies on Agnihotra and illuminate the scientific benefits of Agnihotra rituals and further relate their application as rakshognavidhi (preventive measures) in pregnant women (grabhini), postnatal women (sutika), and in infants (bala). This review covers the concepts of “Agnihotra,” “Mantra,” “Maternal and child health,” “Preconception care,” “Postpartum care” with the hope to evoke more studies and scientific evidences in this area. There were 13 articles selected from PubMed central and two articles from the Cochrane database. These reviews pay attention to the clinical trials and the scientific effect of the ingredients used in the rituals of Agnihotra with their benefits. Agnihotra rituals are practiced by chanting Vedic mantras. The scientific aspects of Agnihotra rituals and their application as rakshognavidhi in pregnant women (grabhini), postnatal women (sutika), and infants (bala) were analyzed with references for the antibacterial, antifungal, and antimicrobial factors that cause sterilization effects. The ingredients such as cow dung cakes, ghee, and rice grains used in these rituals are antimicrobial and hence cause sterilization of the environment. The combined result of all ingredients practiced at the prescribed time produces positive vibrations that enrich electromagnetic radiation and cosmic energy. Such rituals are beneficial for maternal and child health because they maintain physical, mental, and spiritual health.
Efficacy of a Eucalyptus oil-based dentifrice in reducing plaque and gingival bleeding scores – A randomized clinical crossover study
Authors: Osman Fatema Alzahraa , Sarhan Leen Abdulghani , Eladl Nirmeen Elhussein , Desai Vijay , Narayanan Jayaraj , Thangavelu Lakshmi , Varma Sudhir Rama
Published: January 2024

ABSTRACT

Herbal products in dentistry have grown significantly. In the current scenario, herbal products are believed to be an effective adjunct to other medications. The present study aims to evaluate Eucalyptus oil and miswak (Salvadora persica) toothpaste for its efficacy in observable reduction in plaque and gingival bleeding. Sixty participants with gingivitis were enrolled in the present study. The study included an interim period (washout) comparing miswak and Eucalyptus toothpaste. Plaque scores were measured at designated time intervals. Both herbal toothpastes significantly decreased plaque index. Nevertheless, with relation to miswak (P = 0.002), Eucalyptus oil-based toothpaste exhibited reduction in bleeding scores. When participants were asked to return to their routine toothpaste, no changes were observed. Results from the study showed that the toothpaste containing Eucalyptus showed a significant decrease in gingival bleeding. More investigations should be looked on the medicinal applications of Eucalyptus toothpaste on commonly seen periodontal parameters.
Test of insulin resistance in nondiabetic and streptozotocin-induced diabetic rats using glycosylated hemoglobin test and other interventions
Authors: AlTamimi Lina , Zakaraya Zainab Z. , Hailat Mohammad , Ahmad Mousa N. , Qinna Nidal A. , Hamad Mohammed F. , Dayyih Wael Abu
Published: January 2024

ABSTRACT

Type 2 diabetes is common globally. Pioglitazone (PGZ) is an oral TZD antidiabetic, whereas chromium-picolinate (Cr-PL) and Cr-glucose tolerance factor (Cr-GTF) are useful type 2 diabetes mellitus (T2DM) supplements. Cr-PL/GTF antioxidants cure T2DM. They may fail in diabetes with or without insulin-sensitizing medications. It examined how Cr-PL, Cr-GTF, PGZ, and their combination affected glucose, glycosylated hemoglobin, insulin, and HOMA-IR. Sixty-three adult Sprague-Dawley rats (220–300 g) were selected, and nine rats were randomly assigned to a normal nondiabetic group. In contrast, 54 rats were randomly split into 9 rats per each of the 6 major groups and injected intraperitoneally with 40 mg/kg STZ to induce T2DM. Rats were administered PGZ = 0.65 mg/kg (rat weight)/day, Cr-PL = 1 mg/kg, Cr-GTF = 1 mg/kg, and their combinations (PGZ + Cr-PL and Cr-GTF) daily for 6 weeks per intervention. The PGZ + Cr-PL and PGZ + Cr-GTF groups had substantially lower insulin levels than the PGZ group (13.38 ± 0.06, 12.98 ± 0.19 vs. 14.11 ± 0.02, respectively), with the PGZ + Cr-GTF group having the lowest insulin levels (12.98 ± 0.19 vs. 14.11 ± 0.02, 13.38±0.06, respectively). Intervention substantially reduced HOMA-IR in the PZ + Cr-PL and PZ + Cr-GTF groups compared to PGZ (7.49 ± 0.04, 6.69 ± 0.11 vs. 8.37 ± 0.04, respectively). This research found that combining PGZ with Cr-GTF resulted in considerably lower HOMA-IR levels than the PGZ and Cr-PL groups (6.69 ± 0.11 vs. 8.37 ± 0.04, 7.49 ± 0.04, respectively). Both Cr-PL and Cr-GTF may control T2DM. Both Cr complexes improved T2DM biomarkers more than the control diabetic group without medication. PGZ alone and PGZ + Cr-PL had less pharmacological synergy than Cr-GTF and PGZ in altering insulin and HOMA-IR blood levels. These encouraging discoveries need more study.
The interaction of Suk-Saiyasna remedy with GABAA and CB1 receptor-targeting drugs: Enhancing hypnotic and sedative effects in in vivo models
Authors: Damjuti Watchara , Thitikornpong Worathat , Saengow Sinsamut , Thanusuwannasak Thanundorn , Fuangfoo Thanes , Boonruab Jurairat
Published: January 2024

ABSTRACT

The Suk-Saiyasna remedy, an herbal treatment, was historically used but ceased due to its cannabis content. After a relaxation of drug control laws in Thailand, its use re-emerged. This study examines the Suk-Saiyasna remedy’s impact on rodent behavior and its receptor effects. This study was conducted to assess the sedative-like effects of the remedy on mice. The mice were divided into groups receiving 0.6, 3, 30, and 60 mg/kg extracts, with negative controls for comparison. We also investigated the impact on receptors, utilizing negative controls and pretreatment with receptor blockers, followed by either a negative control or a 60 mg/kg extract. Furthermore, this study investigated the behavioral aspects of mice, including anxiolytic effects, antidepressant-like effects, and motor coordination, utilizing the elevated plus-maze, open-field, and rotarod performance tests. The Suk-Saiyasna remedy (P < 0.05) decreased significantly in the latent period and increased sleeping time in the treated groups. Moreover, the Suk-Saiyasna remedy also showed efficacy in reaction to GABAA receptors and cannabinoid CB1 receptors (P < 0.05). In addition, positive effects were observed regarding the animal behavior in the arena, as the animal activity, behavior, and muscle coordination were reduced (P < 0.05). The Suk-Saiyasna remedy may be involved in a sedative–hypnotic-like effect in rodents under normal conditions through the modulation of GABAergic neurons and induction of the cannabinoid CB1 receptor mechanism.