bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combining translational and rotational seismic motions to invert local-scale seismic data for time-variable moment tensors: do rotational motions help for high-frequency seismic data produced by underground explosions?
Authors: Poppeliers Christian , Preston Leiph 
Published: March 2022

SUMMARYWe present an analysis of combining translational and rotational seismic data in an inversion for the time-variable source time functions corresponding to the components of the seismic moment tensor. We conduct a series of numerical experiments where the data are simulated by a combination of an underground explosion and a co-located double couple shear source and recorded on surface-mounted seismometers within 1–2 km of the source. The experiments are designed to mimic explosion seismology experiments, and thus the data are in the 1–10 Hz frequency range and contain very few surface waves. We use a Monte Carlo method to propagate Earth model uncertainty into the estimates of seismic source parameters. In our experiments, we find that the uncertainty of the estimated seismic source parameters increases when we add rotational seismic motions to the inversion when using a constant number of data channels. In this case, the increased degree of uncertainty in the final results is most likely due to the near-surface Earth model uncertainty that we introduce in our simulations. However, for a fixed number of seismic stations, adding rotational seismic motions to the inversion acts to decrease the uncertainty of the estimated seismic source parameters, most likely due to the increase in the number of data channels used in the inversion.
Analysis of tomographic models using resolution and uncertainties: a surface wave example from the Pacific
Authors: Latallerie Franck , Zaroli Christophe , Lambotte Sophie , Maggi Alessia 
Published: March 2022

SUMMARY
Since most tomographic problems deal with imperfect data coverage and noisy data, an estimate of the seismic velocity in the Earth can only be a local average of the ‘true’ velocity with some attached uncertainty. We use the SOLA (subtractive optimally localized averages) method, a Backus–Gilbert-type method based on the resolution–uncertainty trade-off, to build a range of models of Rayleigh-wave velocities in the Pacific upper mantle. We choose one solution and show how to analyse the model using its resolution and uncertainties. We exploit the model statistics to evaluate the significance of deviations from a theoretical prediction: a half-space cooling model of the Pacific lithosphere. We investigate a slow-velocity anomaly located northeast of Hawaii, at about 200 km depth, and a pattern of alternatively slow- and fast-velocity bands, aligned approximately northwest to southeast, between 200 and 300 km depth. According to our resolution and uncertainty analyses, both features seem to be resolved.
The First Fatal Intoxication with 3-MeO-PCP in the UK and a Review of the Literature
Authors: Copeland Caroline S , Hudson Simon , Treble Ric , Hamnett Hilary J 
Published: March 2022

Abstract
The phencyclidine derivative 3-methoxyphencyclidine (3-MeO-PCP) is a potent dissociative hallucinogen. Sought for recreational use as a novel psychoactive substance, it can also induce acute psychological agitation and pathophysiological cardiorespiratory effects. Due to the harms associated with its use, 3-MeO-PCP was added to the “Green List” of materials covered by the 1971 Convention on Psychotropic Substances as a Schedule II substance by the United Nations Commission on Narcotic Drugs in April 2021. There have been 15 previous reports of fatal intoxications following 3-MeO-PCP use, but only one was attributable to 3-MeO-PCP intoxication alone. In this report, we detail the first fatality due to 3-MeO-PCP intoxication to be reported in the UK, along with a review of the surrounding literature. While the blood concentrations associated with 3-MeO-PCP toxicity and fatality remain unclear, by providing details of sample collection and storage conditions, this case will aid in future interpretations. Furthermore, this case suggests that 3-MeO-PCP toxicity may be exacerbated by exercise. Users of 3-MeO-PCP should be cautioned against its use as a “club drug” or in a similar setting where elevations in heart rate, body temperature and blood pressure may occur.
Quantitative 1H-NMR analysis reveals steric and electronic effects on the substrate specificity of benzoate dioxygenase in Ralstonia eutropha B9
Authors: Bent James S , Clark Zachary T , Collins Jonathan A 
Published: March 2022

Abstract
The cis-dihydroxylation of arenes by Rieske dearomatizing dioxygenases (RDDs) represents a powerful tool for the production of chiral precursors in organic synthesis. Here, the substrate specificity of the RDD benzoate dioxygenase (BZDO) in Ralstonia eutropha B9 whole cells was explored using quantitative 1H nuclear magnetic resonance spectroscopy (q1H-NMR). The specific activity, specific carbon uptake, and regioselectivity of the dihydroxylation reaction were evaluated in resting cell cultures for a panel of 17 monosubstituted benzoates. Two new substrates of this dioxygenase system were identified (2-methyl- and 3-methoxybenzoic acid) and the corresponding cis-diol metabolites were characterized. Higher activities were observed for benzoates with smaller substituents, predominantly at the 3-position. Elevated activities were also observed in substrates bearing greater partial charge at the C-2 position of the benzoate ring. The regioselectivity of the reaction was directly measured using q1H-NMR and found to have positive correlation with increasing substituent size. These results widen the pool of cis-diol metabolites available for synthetic applications and offer a window into the substrate traits that govern specificity for BZDO.
Missed Tuberculosis Diagnoses: Analysis of Pediatric Autopsy Data From General Hospitals in Lviv, Ukraine
Authors: Kuzyk Petro V , Padilla Rachel , Rybak Natasha R , Hoshovska Iryna I , Kitov Vasyl O , Savchyna Mariia O , Jenkins Helen E , Chiang Silvia S , Horsburgh Charles Robert , Dolynska Maria , Petrenko Vasyl , Gychka Sergiy G 
Published: March 2022

Abstract
We reviewed autopsy data from general hospitals in Lviv, Ukraine to understand pediatric mortality due to tuberculosis (TB). We identified 14 (0.6%) of 2345 autopsied children with unrecognized or untreated TB. More sensitive TB diagnostics for children and improved strategies for identifying which children require TB evaluation are urgently needed.
Accuracy of power spectra in dissipationless cosmological simulations
Authors: Maleubre Sara , Eisenstein Daniel , Garrison Lehman H , Joyce Michael 
Published: March 2022

AbstractWe exploit a suite of large N-body simulations (up to N = 40963) performed with abacus, of scale-free models with a range of spectral indices n, to better understand and quantify convergence of the matter power spectrum. Using self-similarity to identify converged regions, we show that the maximal wavenumber resolved at a given level of accuracy increases monotonically as a function of time. At 1 per cent level it starts at early times from a fraction of $k_\Lambda$, the Nyquist wavenumber of the initial grid, and reaches at most, if the force softening is sufficiently small, ${\sim}2{-}3 k_\Lambda$ at the very latest times we evolve to. At the $5{{\ \rm per\ cent}}$ level, accuracy extends up to wavenumbers of order $5k_\Lambda$ at late times. Expressed as a suitable function of the scale-factor, accuracy shows a very simple n-dependence, allowing a extrapolation to place conservative bounds on the accuracy of N-body simulations of non-scale-free models like LCDM. We note that deviations due to discretization in the converged range are not well modelled by shot noise, and subtracting it in fact degrades accuracy. Quantitatively our findings are broadly in line with the conservative assumptions about resolution adopted by recent studies using large cosmological simulations (e.g. Euclid Flagship) aiming to constrain the mildly non-linear regime. On the other hand, we remark that conclusions about small-scale clustering (e.g. concerning the validity of stable clustering) obtained using PS data at wavenumbers larger than a few $k_\Lambda$ may need revision in light of our convergence analysis.
Age distribution of stars in boxy/peanut/X-shaped bulges formed without bar buckling
Authors: Baba Junichi , Kawata Daisuke , Schönrich Ralph 
Published: March 2022

ABSTRACT
Some barred galaxies, including the Milky Way, host a boxy/peanut/X-shaped bulge (BPX-shaped bulge). Previous studies suggested that the BPX-shaped bulge can either be developed by bar buckling or by vertical inner Lindblad resonance (vILR) heating without buckling. In this paper, we study the observable consequence of a BPX-shaped bulge built up quickly after bar formation via vILR heating without buckling, using an N-body/hydrodynamics simulation of an isolated Milky Way-like galaxy. We found that the BPX-shaped bulge is dominated by stars born prior to bar formation. This is because the bar suppresses star formation, except for the nuclear stellar disc (NSD) region and its tips. The stars formed near the bar ends have higher Jacobi energy, and when these stars lose their angular momentum, their non-circular energy increases to conserve Jacobi energy. This prevents them from reaching the vILR to be heated to the BPX-shaped bulge region. By contrast, the NSD forms after the bar formation. From this simulation and general considerations, we expect that the age distributions of the NSD and BPX-shaped bulge formed without bar buckling do not overlap each other. Then, the transition age between these components betrays the formation time of the bar, and is testable in future observations of the Milky Way and extragalactic barred galaxies.
Birth cluster simulations of planetary systems with multiple super-Earths: initial conditions for white dwarf pollution drivers
Authors: Stock Katja , Veras Dimitri , Cai Maxwell X , Spurzem Rainer , Portegies Zwart Simon 
Published: March 2022

ABSTRACT
Previous investigations have revealed that eccentric super-Earths represent a class of planets that are particularly effective at transporting minor bodies towards white dwarfs and subsequently polluting their atmospheres with observable chemical signatures. However, the lack of discoveries of these planets beyond a few astronomical units from their host stars prompts a better understanding of their orbital architectures from their nascent birth cluster. Here, we perform stellar cluster simulations of three-planet and seven-planet systems containing super-Earths on initially circular, coplanar orbits. We adopt the typical stellar masses of main-sequence progenitors of white dwarfs ($1.5\, \mathrm{M}_{\odot }$–$2.5\, \mathrm{M}_{\odot }$) as host stars and include 8000 main-sequence stars following a Kroupa initial mass function in our clusters. Our results reveal that about 30 per cent of the simulated planets generate eccentricities of at least 0.1 by the time of cluster dissolution, which would aid white dwarf pollution. We provide our output parameters to the community for potential use as initial conditions for subsequent evolution simulations.
The ultraviolet upturn in field luminous red galaxies at 0.3 &lt; z &lt; 0.7
Authors: De Propris R , Ali S S , Chung C , Bremer M N , Phillipps S 
Published: March 2022

ABSTRACT
We derive the evolution of the ultraviolet upturn colour from a sample of field luminous red galaxies at 0.3 &lt; z &lt; 0.7 with −24 &lt; Mr &lt; −21.5. No individual objects are securely detected, so we stack several hundred galaxies within absolute magnitude and redshift intervals. We find that the colour of the ultraviolet upturn (in observed NUV − i which is approximately equivalent to the classical FUV − V at the redshifts of our targets) does not change strongly with redshift to z = 0.7. This behaviour is similar to that observed in cluster ellipticals over this same mass range and at similar redshifts, and we speculate that the processes involved in the origin of the UV upturn are the same. The observations are most consistent with spectral synthesis models containing a fraction of a helium rich stellar population with abundances between 37 per cent and 42 per cent, although we cannot formally exclude a contribution due to residual star formation at the $\sim 0.5\, \mathrm{ per\,cent}$ level (however, this appears unlikely for cluster galaxies that are believed to be more quenched). This suggests that the ultraviolet upturn is a primordial characteristic of early-type galaxies at all redshifts and that an unexpected nucleosynthesis channel may lead to nearly complete chemical evolution at early times.
Spreading pressure bumps in gas-dust discs can stall planet migration via planet-vortex interactions
Authors: Chametla R O , Chrenko O 
Published: March 2022

ABSTRACT
We investigate the gravitational interaction between low- to intermediate-mass planets ($M_p \in [0.06-210]\, \mathrm{ M}_{\oplus }$) and two previously formed pressure bumps in a gas-dust protoplanetary disc. We explore how the disc structure changes due to planet-induced perturbations and also how the appearance of vortices affects planet migration. We use multifluid 2D hydrodynamical simulations and the dust is treated in the pressureless-fluid approximation, assuming a single grain size of $5\, \mu {\mathrm{m}}$. The initial surface density profiles containing two bumps are motivated by recent observations of the protoplanetary disc HD163296. When planets are allowed to migrate, either a single planet from the outer pressure maximum or two planets from each pressure maximum, the initial pressure bumps quickly spread and merge into a single bump which is radially wide and has a very low amplitude. The redistribution of the disc material is accompanied by the Rossby Wave Instability and an appearance of mini-vortices that merge in a short period of time to form a large vortex. The large vortex induces perturbations with a spiral wave pattern that propagate away from the vortex as density waves. We found that these vortex-induced spiral waves strongly interact with the spiral waves generated by the planet and we called this mechanism the ‘Faraway Interaction’. It facilitates much slower and/or stagnant migration of the planets and it excites their orbital eccentricities in some cases. Our study provides a new explanation for how rocky planets can come to have a slow migration in protoplanetary discs where vortex formation occurs.
On the polytropic Bondi accretion in two-component galaxy models with a central massive BH
Authors: Mancino Antonio , Ciotti Luca , Pellegrini Silvia 
Published: March 2022

ABSTRACT
In many investigations involving accretion on a central point mass, ranging from observational studies to cosmological simulations, including semi-analytical modelling, the classical Bondi accretion theory is the standard tool widely adopted. Previous works generalized the theory to include the effects of the gravitational field of the galaxy hosting a central black hole and of electron scattering in the optically thin limit. Here, we apply this extended Bondi problem, in the general polytropic case, to a class of new two-component galaxy models recently presented. In these models, a Jaffe stellar density profile is embedded in a dark matter halo such that the total density distribution follows a r−3 profile at large radii; the stellar dynamical quantities can be expressed in a fully analytical way. The hydrodynamical properties of the flow are set by imposing that the gas temperature at infinity is proportional to the virial temperature of the stellar component. The isothermal and adiabatic (monoatomic) cases can be solved analytically; in the other cases, we explore the accretion solution numerically. As non-adiabatic accretion inevitably leads to an exchange of heat with the ambient, we also discuss some important thermodynamical properties of the polytropic Bondi accretion and provide the expressions needed to compute the amount of heat exchanged with the environment as a function of radius. The results can be useful for the subgrid treatment of accretion in numerical simulations, as well as for the interpretation of observational data.
Wide-band view of high-frequency quasi-periodic oscillations of GRS 1915+105 in ‘softer’ variability classes observed with AstroSat
Authors: Majumder Seshadri , Sreehari H , Aftab Nafisa , Katoch Tilak , Das Santabrata , Nandi Anuj 
Published: March 2022

ABSTRACT
We present a comprehensive temporal and spectral analysis of the ‘softer’ variability classes (i.e. θ, β, δ, ρ, κ, ω and γ) of the source GRS 1915+105 observed by AstroSat during the 2016−2021 campaign. Wide-band (3−60 keV) timing studies reveal the detection of high-frequency quasi-periodic oscillations (HFQPOs) with frequencies of 68.14−72.32 Hz, significance of 2.75−11σ and rms amplitude of 1.48–2.66 per cent in δ, κ, ω and γ variability classes. Energy-dependent power spectra show that HFQPOs are detected only in the 6−25 keV energy band and rms amplitude is found to increase (1–8 per cent) with energy. The dynamical power spectra of the κ and ω classes demonstrate that HFQPOs seem to be correlated with high count rates. We observe that wide-band (0.7−50 keV) energy spectra can be described by the thermal Comptonization component (nthComp) with a photon index (Γnth) of 1.83−2.89 along with an additional steep (ΓPL ∼ 3) power-law component. The electron temperature (kTe) of 1.82−3.66 keV and optical depth (τ) of 2−14 indicate the presence of a cool and optically thick corona. In addition, nthComp components, 1.97 ≲ Γnth ≲ 2.44 and 1.06 × 10−8 ≲ Fnth (erg cm−2 s−1) ≲ 4.46 × 10−8, are found to dominate in the presence of HFQPOs. Overall, these findings infer that HFQPOs are possibly the result of the modulation of the ‘Comptonizing corona’. Further, we find that the bolometric luminosity (0.3−100 keV) of the source lies within the sub-Eddington (3–34 per cent LEdd) regime. Finally, we discuss and compare the obtained results in the context of existing models on HFQPOs.
The spins of the Galactic black holes in MAXI J1535–571 and 4U 1630–472 from Insight-HXMT
Authors: Liu Qichun , Liu Honghui , Bambi Cosimo , Ji Long 
Published: March 2022

ABSTRACT
Insight-HXMT is the first Chinese X-ray astronomical mission. With a 1–250 keV bandpass, an energy resolution of 150 eV at 6 keV, and without being subject to pile-up distortions, it is suitable to study bright X-ray sources like Galactic black holes. In this paper, we study Insight-HXMT observations of the X-ray binaries MAXI J1535–571 and 4U 1630–472 during their outbursts in 2017 and 2020, respectively. From the analysis of the reflection features, we are able to infer the black hole spin parameter in the two sources. For MAXI J1535–571, we find a spin parameter very close to 1, a* = 0.9916 ± 0.0012 (90 per cent C.L., statistical error), which is consistent with the previous NuSTAR measurement. For 4U 1630–472, we find a moderately high value of the black hole spin parameter, a* = 0.817 ± 0.014 (90 per cent C.L., statistical error), which is lower than the almost extremal value found with NuSTAR data.
Stellar multiplicity affects the correlation between protoplanetary disc masses and accretion rates: binaries explain high accretors in Upper Sco
Authors: Zagaria Francesco , Clarke Cathie J , Rosotti Giovanni P , Manara Carlo F 
Published: March 2022

ABSTRACT
In recent years, a correlation between mass accretion rates onto new-born stars and their protoplanetary disc masses was detected in nearby young star-forming regions. Although such a correlation can be interpreted as due to viscous-diffusion processes in the disc, highly accreting sources with low disc masses in more evolved regions remain puzzling. In this paper, we hypothesize that the presence of a stellar companion truncating the disc can explain these outliers. First, we searched the literature for information on stellar multiplicity in Lupus, Chamaeleon I, and Upper Sco, finding that roughly 20 per cent of the discs involved in the correlation are in binaries or higher order multiple stellar systems. We prove with high statistical significance that at any disc mass these sources have systematically higher accretion rates than those in single-stars, with the bulk of the binary population being clustered around $M_\mathrm{disc}/\dot{M}_\mathrm{acc}\approx 0.1\, \mathrm{Myr}$. We then run coupled gas and dust one-dimensional evolutionary models of tidally truncated discs to be compared with the data. We find that these models are able to reproduce well most of the population of observed discs in Lupus and Upper Sco, even though the unknown eccentricity of each binary prevents an object by object comparison. In the latter region, the agreement improves if the grain coagulation efficiency is reduced, as may be expected in discs around close binaries. Finally, we mention that thermal winds and sub-structures can be important in explaining few outlying sources.
Expanding the DNA-encoded library toolbox: identifying small molecules targeting RNA
Authors: Chen Qiuxia , Li You , Lin Chunrong , Chen Liu , Luo Hao , Xia Shuai , Liu Chuan , Cheng Xuemin , Liu Chengzhong , Li Jin , Dou Dengfeng 
Published: March 2022

AbstractDNA-encoded library (DEL) technology is a powerful tool for small molecule identification in drug discovery, yet the reported DEL selection strategies were applied primarily on protein targets in either purified form or in cellular context. To expand the application of this technology, we employed DEL selection on an RNA target HIV-1 TAR (trans-acting responsive region), but found that the majority of signals were resulted from false positive DNA–RNA binding. We thus developed an optimized selection strategy utilizing RNA patches and competitive elution to minimize unwanted DNA binding, followed by k-mer analysis and motif search to differentiate false positive signal. This optimized strategy resulted in a very clean background in a DEL selection against Escherichia coli FMN Riboswitch, and the enriched compounds were determined with double digit nanomolar binding affinity, as well as similar potency in functional FMN competition assay. These results demonstrated the feasibility of small molecule identification against RNA targets using DEL selection. The developed experimental and computational strategy provided a promising opportunity for RNA ligand screening and expanded the application of DEL selection to a much wider context in drug discovery.
Inferring the contribution of small RNAs to changes in gene expression in response to stress
Authors: Barsheshet Meshi , Fisher Shira , Margalit Hanah 
Published: March 2022

AbstractA main strategy of bacteria adapting to environmental changes is the remodeling of their transcriptome. Changes in the transcript levels of specific genes are due to combined effects of various regulators, including small RNAs (sRNAs). sRNAs are post-transcriptional regulators of gene expression that mainly control translation, but also directly and indirectly affect the levels of their target transcripts. Yet, the relative contribution of an sRNA to the total change in the transcript level of a gene upon an environmental change has not been assessed. We present a design of differential gene expression analysis by RNA-seq that allows extracting the contribution of an sRNA to the total change in the transcript level of each gene in response to an environmental change by fitting a linear model to the data. We exemplify this for the sRNA RyhB in cells growing under iron limitation and show a variation among genes in the relative contribution of RyhB to the change in their transcript level upon iron limitation, from subtle to very substantial. Extracting the relative contribution of an sRNA to the total change in expression of genes is important for understanding the integration of regulation by sRNAs with other regulatory mechanisms in the cell.