bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of dasabuvir inhibition of acetaminophen glucuronidation
Authors: Zhang Qingchen , Duan Su Xiang , Harmatz Jerold S , Wei Zixuan , Singleton Christopher A , Greenblatt David J 
Published: September 2021

Abstract

Objectives
Acetaminophen (APAP) (paracetamol) is a widely used non-prescription drug for pain relief and antipyretic effects. The clearance of APAP is mainly through phase-2 biotransformation catalysed by UDP-glucuronosyl transferases (UGT). Dasabuvir is an anti-hepatitis C drug reported to inhibit several UGT isoforms. The study evaluated the in-vitro inhibitory capacity of dasabuvir versus APAP glucuronidation.

Methods
Procedures included human liver microsomal incubations with APAP and isoform-selective probe substrates.

Key findings
Dasabuvir inhibited APAP metabolism by a reversible, mixed-type (competitive and non-competitive) partial inhibition, with an inhibition constant Ki = 3.4 µM. The index constant ‘a’ was 6.7, indicating the relative contribution of competitive and non-competitive inhibition. The enzyme-inhibitor complex was still able to catalyse the reaction by 12% of the control capacity. Dasabuvir produced strong partial inhibition effect of UGT1A1 and UGT1A9 and relatively complete inhibition of UGT1A6.

Conclusions
Consistent with previous reports, dasabuvir inhibits the activity of 3 UGT isoforms associated with APAP metabolism. In-vitro to in-vivo scaling by 2 different approaches showed identical results, predicting an increased AUC of APAP by a factor of 1.3-fold with coadministration of dasabuvir. Until the findings are confirmed in clinical drug interaction studies, APAP dosage should not exceed 3 g per day in dasabuvir-treated patients to avoid potentially hepatotoxic APAP exposures.
Surgical correction of foot equino-cavocarus deformity in Klippel-Trénaunay-Weber syndrome: a case report
Authors: Arafa Orfan M , Alzuhair Abduljabar R , Alharbi Sultan K , Alromaih Norah I 
Published: September 2021

Abstract
Klippel-Trénaunay-Weber syndrome (KTWS) is a rare condition characterized by a classic clinical triad. However, it can also have other features, such as cavocarus foot deformity, which is a rare presentation in a patient with KTWS. In this case report, we present our surgical technique of correcting such a complex deformity. Also, there are no other similar cases reported in the literature. An 18-year-old girl who is a known case of KTWS with a complaint of progressive unilateral left foot deformity. Her examination, revealed a rigid pes cavus with an equinus deformity in the left foot. Radiography of the left foot revealed marked cavus as well as hindfoot and forefoot varus. A successful surgical correction of the deformity was described in a stepwise fashion. The management of foot cavocarus deformity in KTWS patients is associated with high intra- and post-operative risk due to its complexity. Therefore, the management requires a multidisciplinary team approach.
Linguistic features evaluation for hadith authenticity through automatic machine learning
Authors: Mohamed Emad , Sarwar Raheem 
Published: September 2021

Abstract
There has not been any research that provides an evaluation of the linguistic features extracted from the matn (text) of a Hadith. Moreover, none of the fairly large corpora are publicly available as a benchmark corpus for Hadith authenticity, and there is a need to build a ‘gold standard’ corpus for good practices in Hadith authentication. We write a scraper in Python programming language and collect a corpus of 3,651 authentic prophetic traditions and 3,593 fake ones. We process the corpora with morphological segmentation and perform extensive experimental studies using a variety of machine learning algorithms, mainly through automatic machine learning, to distinguish between these two categories. With a feature set including words, morphological segments, characters, top N words, top N segments, function words, and several vocabulary richness features, we analyze the results in terms of both prediction and interpretability to explain which features are more characteristic of each class. Many experiments have produced good results and the highest accuracy (i.e. 78.28%) is achieved using word n-grams as features using the Multinomial Naive Bayes classifier. Our extensive experimental studies conclude that, at least for Digital Humanities, feature engineering may still be desirable due to the high interpretability of the features. The corpus and software (scripts) will be made publicly available to other researchers in an effort to promote progress and replicability.
High-resolution parameter study of the vertical shear instability – II: dependence on temperature gradient and cooling time
Authors: Manger Natascha , Pfeil Thomas , Klahr Hubert 
Published: September 2021

ABSTRACT
A certain appeal to the alpha model for turbulence and related viscosity in accretion discs was that one scales the Reynolds stresses simply on the thermal pressure, assuming that turbulence driven by a certain mechanism will attain a characteristic Mach number in its velocity fluctuations. Besides the notion that there are different mechanism driving turbulence and angular momentum transport in a disc, we also find that within a single instability mechanism, here the vertical shear instability, stresses do not linearly scale with thermal pressure. Here, we demonstrate in numerical simulations the effect of the gas temperature gradient and the thermal relaxation time on the average stresses generated in the non-linear stage of the instability. We find that the stresses scale with the square of the exponent of the radial temperature profile at least for a range of dlog T/dlog R = [−0.5, −1], beyond which the pressure scale height varies too much over the simulation domain, to provide clear results. Stresses are also dependent on thermal relaxation times, provided they are longer than 10−3 orbital periods. The strong dependence of viscous transport of angular momentum on the local conditions in the disc (especially temperature, temperature gradient, and surface density/optical depth) challenges the ideas of viscosity leading to smooth density distributions, opening a route for structure (ring) formation and time variable mass accretion.
Can high-velocity protostellar jets help to drive low-velocity outflow?
Authors: Machida Masahiro N 
Published: September 2021

ABSTRACT
Using three-dimensional magnetohydrodynamics simulations, the driving of protostellar jets is investigated in different star-forming cores with the parameters of magnetic field strength and mass accretion rate. Powerful high-velocity jets appear in strongly magnetized clouds when the mass accretion rate on to the protostellar system is lower than $\dot{M} \lesssim 10^{-4}\, {\rm M}_\odot$ yr−1. On the other hand, even at this mass accretion rate range, no jets appear for magnetic fields of prestellar clouds as weak as μ0 ≳ 5–10, where μ0 is the mass-to-flux ratio normalized by the critical value (2πG1/2)−1. For $\dot{M}\gtrsim 10^{-4}\, {\rm M}_\odot$ yr−1, although jets usually appear just after protostar formation independent of the magnetic field strength, they soon weaken and finally disappear. Thus, they cannot help drive the low-velocity outflow when there is no low-velocity flow just before protostar formation. As a result, no significant mass ejection occurs during the early mass accretion phase either when the prestellar cloud is weaky magnetized or when the mass accretion rate is very high. Thus, protostars formed in such environments would trace different evolutionary paths from the normal star formation process.
Mass accretion rates and multiscale halo environment in cold and warm dark matter cosmologies
Authors: Dhoke Payaswinee , Paranjape Aseem 
Published: September 2021

ABSTRACT
We study the evolving environment dependence of mass accretion by dark haloes in simulations of cold and warm dark matter (CDM and WDM) cosmologies. The latter allows us to probe the nature of halo growth at scales below the WDM half-mode mass, which form an extreme regime of non-linear collisionless dynamics and offer an excellent test-bed for ideas relating to hierarchical growth. As environmental proxies, we use the local halo-centric matter density δ and tidal anisotropy α, as well as large-scale halo bias b1. Our analysis, while reproducing known trends for environment-dependent accretion in CDM, as well as the comparison between accretion in CDM and WDM, reveals several interesting new features. As expected from excursion set models, WDM haloes have higher specific accretion rates, dominated by the accretion of diffuse mass, as compared to CDM haloes. For low-mass WDM haloes, we find that the environment-dependence of both diffuse mass accretion as well as accretion by mergers is almost fully explained by α. For the other cases, δ plays at least a comparable role. We detect, for the first time, a significant and evolving assembly bias due to diffuse mass accretion for low-mass CDM and WDM haloes (after excluding splashback objects), with a z = 0 strength higher than with almost all known secondary variables and largely explained by α. Our results place constraints on semi-analytical merger tree algorithms, which in turn could affect the predictions of galaxy evolution models based on them.
A panoramic view of the Local Group dwarf galaxy NGC 6822
Authors: Zhang Shumeng , Mackey Dougal , Da Costa Gary S 
Published: September 2021

ABSTRACT
We present a panoramic survey of the isolated Local Group dwarf irregular galaxy NGC 6822. Our photometry reaches ∼2–3 mag deeper than most previous studies and spans the widest area around the dwarf compared to any prior work. We observe no stellar overdensities in the outskirts of NGC 6822 to V ∼ 30 mag arcsec−2 and a projected radius of 16.5 kpc. This indicates that NGC 6822 has not experienced any recent interaction with a companion galaxy, despite previous suggestions to the contrary. Similarly, we find no evidence for any dwarf satellites of NGC 6822 to a limiting luminosity MV ≈ −5. NGC 6822 contains a disc of H i gas and young stars, oriented at ∼60○ to an extended spheroid composed of old stellar populations. We observe no correlation between the distribution of young stars and spheroid members. Our imaging allows us to trace the spheroid to nearly 11 kpc along its major axis, commensurate with the extent of the NGC 6822 globular cluster system. We find that the spheroid becomes increasingly flattened at larger radii, and its position angle twists by up to 40○. We use Gaia EDR3 astrometry to measure a proper motion for NGC 6822, and then sample its orbital parameter space. While this galaxy has spent the majority of its life in isolation, we find that it likely passed within the virial radius of the Milky Way ∼3–4 Gyr ago. This may explain the apparent flattening and twisting observed in the outskirts of its spheroid.
MIGHTEE-H i: the baryonic Tully–Fisher relation over the last billion years
Authors: Ponomareva Anastasia A , Mulaudzi Wanga , Maddox Natasha , Frank Bradley S , Jarvis Matt J , Teodoro Enrico M Di , Glowacki Marcin , Kraan-Korteweg Renée C , Oosterloo Tom A , Adams Elizabeth A K , Pan Hengxing , Prandoni Isabella , Rajohnson Sambatriniaina H A , Sinigaglia Francesco , Adams Nathan J , Heywood Ian , Bowler Rebecca A A , Hatfield Peter W , Collier Jordan D , Sekhar Srikrishna 
Published: September 2021

ABSTRACT
Using a sample of 67 galaxies from the MeerKAT International GigaHertz Tiered Extragalactic Exploration Survey Early Science data, we study the H i-based baryonic Tully–Fisher relation (bTFr), covering a period of ∼1 billion years (0 ≤ z ≤ 0.081). We consider the bTFr based on two different rotational velocity measures: the width of the global H i profile and Vout, measured as the outermost rotational velocity from the resolved H i rotation curves. Both relations exhibit very low intrinsic scatter orthogonal to the best-fitting relation (σ⊥ = 0.07 ± 0.01), comparable to the SPARC sample at z ≃ 0. The slopes of the relations are similar and consistent with the z ≃ 0 studies ($3.66^{+0.35}_{-0.29}$ for W50 and $3.47^{+0.37}_{-0.30}$ for Vout). We find no evidence that the bTFr has evolved over the last billion years, and all galaxies in our sample are consistent with the same relation independent of redshift and the rotational velocity measure. Our results set-up a reference for all future studies of the H i-based bTFr as a function of redshift that will be conducted with the ongoing deep SKA pathfinders surveys.
Lyman-alpha emitters and the 21 cm power spectrum as probes of density–ionization correlation in the epoch of reionization
Authors: Pagano Michael , Liu Adrian 
Published: September 2021

ABSTRACT
Due to the large cross-section of Ly α photons with hydrogen, Lyman-alpha emitters (LAEs) are sensitive to the presence of neutral hydrogen in the intergalactic medium (IGM) during the epoch of reionization (EoR): the period in the Universe’s history where neutral hydrogen in the IGM is ionized. The type of correlation between the ionized regions of the IGM with respect to the underlying intrinsic LAEs has a pronounced effect on the number of observed LAEs and their apparent clustering. As a result, observations of LAEs during the EoR can be used as a probe of the EoR morphology. Here, we build on previous works where we parametrize the density–ionization correlation during the EoR, and study how the observed number density and angular correlation function (ACF) of LAEs depend on this parametrization. Using Subaru measurements of the number density of LAEs and their ACF at z = 6.6, we place constraints on the EoR morphology. We find that measurements of LAEs at z = 6.6 alone cannot distinguish between different density–ionization models at $68{{\ \rm per\ cent}}$ credibility. However, adding information regarding the number density, and ACF, of LAEs at z = 6.6 to 21 cm power spectrum measurements using the hydrogen Epoch of Reionization Array at the mid-point of reionization can rule out uncorrelated and outside-in reionization at $99{{\ \rm per\ cent}}$ credibility.
Parker Solar Probe observations of helical structures as boundaries for energetic particles
Authors: Pecora F , Servidio S , Greco A , Matthaeus W H , McComas D J , Giacalone J , Joyce C J , Getachew T , Cohen C M S , Leske R A , Wiedenbeck M E , McNutt R L , Hill M E , Mitchell D G , Christian E R , Roelof E C , Schwadron N A , Bale S D 
Published: September 2021

ABSTRACT
Energetic particle transport in the interplanetary medium is known to be affected by magnetic structures. It has been demonstrated for solar energetic particles in near-Earth orbit studies, and also for the more energetic cosmic rays. In this paper, we show observational evidence that intensity variations of solar energetic particles can be correlated with the occurrence of helical magnetic flux tubes and their boundaries. The analysis is carried out using data from Parker Solar Probe orbit 5, in the period 2020 May 24 to June 2. We use FIELDS magnetic field data and energetic particle measurements from the Integrated Science Investigation of the Sun (IS⊙IS) suite on the Parker Solar Probe. We identify magnetic flux ropes by employing a real-space evaluation of magnetic helicity, and their potential boundaries using the Partial Variance of Increments method. We find that energetic particles are either confined within or localized outside of helical flux tubes, suggesting that the latter act as transport boundaries for particles, consistent with previously developed viewpoints.
Identifying distinct metrics for assessing night sky brightness
Authors: Hung Li-Wei 
Published: September 2021

ABSTRACT
Studying light pollution is an interest to researchers in a wide range of fields including astronomy, biology, civil engineering, ecology, and social science. Consequently, numerous sky brightness metrics have been developed over the years. However, what metrics are truly representative of the night sky quality and unique to the measured feature? The US National Park Service Night Skies Program has collected more than 1500 sets of night skies data throughout the United States. For each data set, a maximum of 56 metrics were measured through the combination of the captured images, Sky Quality Meter readings, and visual observations. This paper analyses these measurements and identifies a distinctive set of night sky brightness metrics based on the principal component analysis. Three major findings emerge. First, the commonly used metrics, such as the zenith brightness, horizontal illuminance, maximum vertical illuminance, all-sky light pollution ratio, Bortle class, and limiting magnitude, are highly correlated. Secondly, the observed sky brightness often offers a good estimate of the artificial light level despite the natural varying night sky background. Thirdly, a set of six metrics that consists of the zenith brightness and sky brightness percentiles are more distinctive when used to concisely describe night sky characteristics. These findings suggest that long-term night sky monitoring can be efficiently carried out by measuring the sky brightness percentiles on the observed all-sky images.
Revisiting the Cygnus OB associations
Authors: Quintana Alexis L , Wright Nicholas J 
Published: September 2021

ABSTRACT
OB associations play an important role in Galactic evolution, though their origins and dynamics remain poorly studied, with only a small number of systems analysed in detail. In this paper, we revisit the existence and membership of the Cygnus OB associations. We find that of the historical OB associations only Cyg OB2 and OB3 stand out as real groups. We search for new OB stars using a combination of photometry, astrometry, evolutionary models, and an SED-fitting process, identifying 4680 probable OB stars with a reliability of &gt;90 per cent. From this sample, we search for OB associations using a new and flexible clustering technique, identifying six new OB associations. Two of these are similar to the associations Cyg OB2 and OB3, though the others bear no relationship to any existing systems. We characterize the properties of the new associations, including their velocity dispersions and total stellar masses, all of which are consistent with typical values for OB associations. We search for evidence of expansion and find that all are expanding, albeit anisotropically, with stronger and more significant expansion in the direction of Galactic longitude. We also identify two large-scale (160 pc and 25 km s−1) kinematic expansion patterns across the Cygnus region, each including three of our new associations, and attribute this to the effects of feedback from a previous generation of stars. This work highlights the need to revisit the existence and membership of the historical OB associations, if they are to be used to study their properties and dynamics.
Advances in control of a pyramid single conjugate adaptive optics system
Authors: Agapito Guido , Rossi Fabio , Plantet Cedric , Puglisi Alfio , Pinna Enrico 
Published: September 2021

ABSTRACT
Adaptive optics systems are an essential technology for the modern astronomy for ground-based telescopes. One of the most recent revolution in the field is the introduction of the pyramid wavefront sensor. The higher performance of this device is paid with increased complexity in the control. In this work, we report about advances in the adaptive optics (AO) system control obtained with SOUL at the Large Binocular Telescope. The first is an improved Tip/Tilt temporal control able to recover the nominal correction even in presence of high temporal frequency resonances. The second one is a modal gain optimization that has been successfully tested on sky for the first time. Pyramid wavefront sensors are the key technology for the first light AO systems of all Extremely Large Telescopes and the reported advances can be relevant contributions for such systems.
Structure of an inactive RNA polymerase II dimer
Authors: Aibara Shintaro , Dienemann Christian , Cramer Patrick 
Published: September 2021

Abstract
Eukaryotic gene transcription is carried out by three RNA polymerases: Pol I, Pol II and Pol III. Although it has long been known that Pol I can form homodimers, it is unclear whether and how the two other RNA polymerases dimerize. Here we present the cryo-electron microscopy (cryo-EM) structure of a mammalian Pol II dimer at 3.5 Å resolution. The structure differs from the Pol I dimer and reveals that one Pol II copy uses its RPB4-RPB7 stalk to penetrate the active centre cleft of the other copy, and vice versa, giving rise to a molecular handshake. The polymerase clamp domain is displaced and mobile, and the RPB7 oligonucleotide-binding fold mimics the DNA–RNA hybrid that occupies the cleft during active transcription. The Pol II dimer is incompatible with nucleic acid binding as required for transcription and may represent an inactive storage form of the polymerase.
Quantitative assessment of engineered Cas9 variants for target specificity enhancement by single-molecule reaction pathway analysis
Authors: Bak So Young , Jung Youngri , Park Jinho , Sung Keewon , Jang Hyeon-Ki , Bae Sangsu , Kim Seong Keun 
Published: September 2021

Abstract
There have been many engineered Cas9 variants that were developed to minimize unintended cleavage of off-target DNAs, but detailed mechanism for the way they regulate the target specificity through DNA:RNA heteroduplexation remains poorly understood. We used single-molecule FRET assay to follow the dynamics of DNA:RNA heteroduplexation for various engineered Cas9 variants with respect to on-target and off-target DNAs. Just like wild-type Cas9, these engineered Cas9 variants exhibit a strong correlation between their conformational structure and nuclease activity. Compared with wild-type Cas9, the fraction of the cleavage-competent state dropped more rapidly with increasing base-pair mismatch, which gives rise to their enhanced target specificity. We proposed a reaction model to quantitatively analyze the degree of off-target discrimination during the successive process of R-loop expansion. We found that the critical specificity enhancement step is activated during DNA:RNA heteroduplexation for evoCas9 and HypaCas9, while it occurs in the post-heteroduplexation stage for Cas9-HF1, eCas9, and Sniper-Cas9. This study sheds new light on the conformational dynamics behind the target specificity of Cas9, which will help strengthen its rational designing principles in the future.