bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constraining black hole feedback in galaxy clusters from X-ray power spectra
Authors: Heinrich Annie , Chen Yi-Hao , Heinz Sebastian , Zhuravleva Irina , Churazov Eugene 
Published: May 2021

ABSTRACT
Jets launched by the supermassive black holes in the centres of cool-core clusters are the most likely heat source to solve the cooling flow problem. One way for this heating to occur is through generation of a turbulent cascade by jet-inflated bubbles. Measurements of the X-ray intensity power spectra show evidence of this cascade in different regions of the cluster, constraining the role of driving mechanisms. We analyse feedback simulations of the Perseus cluster to constrain the effect of the jet activity on the intensity fluctuations and kinematics of the cluster atmosphere. We find that, within the inner 60 kpc, the power spectra of the predicted surface brightness fluctuations are broadly consistent with those measured by Chandra and that even a single episode of jet activity can generate a long-lasting imprint on the intensity fluctuations in the innermost region of the cluster. Active galactic nucleus (AGN)-driven motions within the same region approach the values reported by Hitomi during and right after the AGN episode. However, the line-of-sight velocity dispersion excited by the jet in simulations underpredicts the Hitomi measurement. This indicates that driving a volume-filling sustained level of turbulence requires several episodes of jet activity, and/or additional processes drive turbulence outside the 60-kpc sphere. This also suggests that sharp edges of the bubbles in the innermost region of the cluster contribute substantially to the intensity of fluctuations, consistent with the Perseus observations in the inner 30-kpc region. We discuss new diagnostics to decompose annular power spectra to constrain past episodes of jet activity.
Binary black hole mergers from hierarchical triples in open clusters
Authors: Britt Dylan , Johanson Ben , Wood Logan , Miller M Coleman , Michaely Erez 
Published: May 2021

ABSTRACT
A promising channel for producing binary black hole mergers is the Lidov–Kozai orbital resonance in hierarchical triple systems. While this mechanism has been studied in isolation, the distribution of such mergers in time and across star-forming environments is not well characterized. In this work, we explore Lidov–Kozai-induced black hole mergers in open clusters, combining semi-analytical and Monte Carlo methods to calculate merger rates and delay times for nine different population models. We predict a merger rate density of ∼1–10 Gpc−3 yr−1 for the Lidov–Kozai channel in the local Universe, and all models yield delay-time distributions in which a significant fraction of binary black hole mergers (e.g. ∼20–50 per cent in our baseline model) occur during the open cluster phase. Our findings suggest that a substantial fraction of mergers from hierarchical triples occur within star-forming regions in spiral galaxies.
The galaxy size–halo mass scaling relations and clustering properties of central and satellite galaxies
Authors: Rodriguez Facundo , Montero-Dorta Antonio D , Angulo Raul E , Artale M Celeste , Merchán Manuel 
Published: May 2021

ABSTRACT
In this work, we combine size and stellar mass measurements from the Sloan Digital Sky Server (SDSS) with the group finder algorithm of Rodriguez & Merchán in order to determine the stellar and halo mass–size relations of central and satellite galaxies separately. We show that, while central and satellite galaxies display similar stellar mass–size relations, their halo mass–size relations differ significantly. As expected, more massive haloes tend to host larger central galaxies. However, the size of satellite galaxies depends only slightly on halo virial mass. We show that these results are compatible with a remarkably simple model in which the size of central and satellite galaxies scales as the cubic root of their host halo mass, with the normalization for satellites being ∼30 per cent smaller than that for central galaxies, which can be attributed to tidal stripping. We further check that our measurements are in excellent agreement with predictions from the IllustrisTNG hydrodynamical simulation. In the second part of this paper, we analyse how the clustering properties of central and satellite galaxies depend on their size. We demonstrate that, independently of the stellar mass threshold adopted, smaller galaxies are more tightly clustered than larger galaxies when either the entire sample or only satellites are considered. The opposite trend is observed on large scales when the size split is performed for the central galaxies alone. Our results place significant constraints for halo–galaxy connection models that link galaxy size with the properties of their hosting haloes.
A long-term multifrequency study of solar rotation using the solar radio flux and its relationship with solar cycles
Authors: Singh Vivek Kumar , Chandra Satish , Thomas Sanish , Sharma Som Kumar , Vats Hari Om 
Published: May 2021

ABSTRACT
This paper examines long-term (more than four solar cycles) temporal and spatial fluctuations in the solar rotation by investigating radio-emission escapes from various layers of the solar atmosphere during the years 1967–2010. The flux modulation approach can also be used to investigate variations in solar rotation, which is a contentious topic in solar physics. This study makes use of a time-series of radio flux data at various frequencies (245–15 400 MHz) obtained at Sagamore Hill Solar Radio Observatory in Massachusetts, USA, and at other observatories from 1967 to 2010. The periodicity present in the temporal variation of the time-series is estimated through a Lomb–Scargle periodogram. The rotation period estimated for five radio emissions (606, 1415, and 2695 MHz from the corona, and 4995 and 8800 MHz from the transition region) through a statistical approach shows continuous temporal and spatial variations throughout the years. The smoothed rotation period shows the presence of periodic ∼22-yr and ∼11-yr components. The 22-yr component could be linked to the reversal of the solar magnetic field (Hale) cycle, while the 11-yr component is most likely related to the sunspot (Schwabe) cycle. In addition to these two components, random components are also prominently present in the analysed data. The cross-correlation between the sunspot number and the rotation period obtained shows a strong correlation with the 11-yr Schwabe and 22-yr Hale cycle. The corona rotates faster or slower than the transition region in different epochs. The alternation of the faster rotation speed between the corona and transition region also follows the 22-yr cycle.
Atomistic basis of force generation, translocation, and coordination in a viral genome packaging motor
Authors: Pajak Joshua , Dill Erik , Reyes-Aldrete Emilio , White Mark A , Kelch Brian A , Jardine Paul J , Arya Gaurav , Morais Marc C 
Published: May 2021

AbstractDouble-stranded DNA viruses package their genomes into pre-assembled capsids using virally-encoded ASCE ATPase ring motors. We present the first atomic-resolution crystal structure of a multimeric ring form of a viral dsDNA packaging motor, the ATPase of the asccφ28 phage, and characterize its atomic-level dynamics via long timescale molecular dynamics simulations. Based on these results, and previous single-molecule data and cryo-EM reconstruction of the homologous φ29 motor, we propose an overall packaging model that is driven by helical-to-planar transitions of the ring motor. These transitions are coordinated by inter-subunit interactions that regulate catalytic and force-generating events. Stepwise ATP binding to individual subunits increase their affinity for the helical DNA phosphate backbone, resulting in distortion away from the planar ring towards a helical configuration, inducing mechanical strain. Subsequent sequential hydrolysis events alleviate the accumulated mechanical strain, allowing a stepwise return of the motor to the planar conformation, translocating DNA in the process. This type of helical-to-planar mechanism could serve as a general framework for ring ATPases.
sRNA-mediated RNA processing regulates bacterial cell division
Authors: Grützner Julian , Remes Bernhard , Eisenhardt Katrin M H , Scheller Daniel , Kretz Jonas , Madhugiri Ramakanth , McIntosh Matthew , Klug Gabriele 
Published: May 2021

Abstract
Tight control of cell division is essential for survival of most organisms. For prokaryotes, the regulatory mechanisms involved in the control of cell division are mostly unknown. We show that the small non-coding sRNA StsR has an important role in controlling cell division and growth in the alpha-proteobacterium Rhodobacter sphaeroides. StsR is strongly induced by stress conditions and in stationary phase by the alternative sigma factors RpoHI/HII, thereby providing a regulatory link between cell division and environmental cues. Compared to the wild type, a mutant lacking StsR enters stationary phase later and more rapidly resumes growth after stationary phase. A target of StsR is UpsM, the most abundant sRNA in the exponential phase. It is derived from partial transcriptional termination within the 5′ untranslated region of the mRNA of the division and cell wall (dcw) gene cluster. StsR binds to UpsM as well as to the 5′ UTR of the dcw mRNA and the sRNA-sRNA and sRNA-mRNA interactions lead to a conformational change that triggers cleavage by the ribonuclease RNase E, affecting the level of dcw mRNAs and limiting growth. These findings provide interesting new insights into the role of sRNA-mediated regulation of cell division during the adaptation to environmental changes.
Fecal Microbiota Functional Gene Effects Related to Single-Dose Antibiotic Treatment of Travelers’ Diarrhea
Authors: Johnson Ryan C , Van Nostrand Joy D , Tisdale Michele , Swierczewski Brett , Simons Mark P , Connor Patrick , Fraser Jamie , Melton-Celsa Angela R , Tribble David R , Riddle Mark S 
Published: May 2021

Abstract

Background
Travelers’ diarrhea (TD) is common among military personnel deployed to tropical and subtropical regions. It remains unclear how TD and subsequent antibiotic treatment impact the resident microflora within the gut, especially given increased prevalence of antibiotic resistance among enteric pathogens and acquisition of multidrug-resistant organisms. We examined functional properties of the fecal microflora in response to TD, along with subsequent antibiotic treatment.

Methods
Fecal samples from US and UK military service members deployed to Djibouti, Kenya, and Honduras who presented with acute watery diarrhea were collected. A sample was collected at acute presentation to the clinic (day 0, before antibiotics), as well as 7 and/or 21 days following a single dose of antibiotics (azithromycin [500 mg], levofloxacin [500 mg], or rifaximin [1650 mg], all with loperamide). Each stool sample underwent culture and TaqMan reverse transcription polymerase chain reaction analyses for pathogen and antibiotic resistance gene detection. Purified DNA from each sample was analyzed using the HumiChip3.1 functional gene array.

Results
In total, 108 day 1 samples, 50 day 7 samples, and 94 day 21 samples were available for analysis from 119 subjects. Geographic location and disease severity were associated with distinct functional compositions of fecal samples. There were no overt functional differences between pre- and postantibiotic treatment samples, nor was there increased acquisition of antibiotic resistance determinants for any of the antibiotic regimens.

Conclusions
These results indicate that single-dose antibiotic regimens may not drastically alter the functional or antibiotic resistance composition of fecal microflora, which should inform clinical practice guidelines and antimicrobial stewardship.

Clinical Trials Registration Number
NCT01618591.
The Generation of Arc Andesites and Dacites in the Lower Crust of a Cordilleran Arc, Fiordland, New Zealand
Authors: Carty Kendra , Schwartz Joshua J , Wiesenfeld John , Klepeis Keith A , Stowell Harold H , Tulloch Andy J , Barnes Calvin G 
Published: May 2021

Abstract
We present microbeam major- and trace-element data from 14 monzodiorites collected from the Malaspina Pluton (Fiordland, New Zealand) with the goal of evaluating processes involved in the production of andesites in lower arc crust. We focus on relict igneous assemblages consisting of plagioclase and amphibole with lesser amounts of clinopyroxene, orthopyroxene, biotite and quartz. These relict igneous assemblages are heterogeneously preserved in the lower crust within sheeted intrusions that display hypersolidus fabrics defined by alignment of unstrained plagioclase and amphibole. Trace-element data from relict igneous amphiboles in these rocks reveal two distinct groups: one relatively enriched in high field strength element concentrations and one relatively depleted. The enriched amphibole group has Zr values in the range of ∼25–110 ppm, Nb values of ∼5–32 ppm, and Th values up to 2·4 ppm. The depleted group, in contrast, shows Zr values &lt;35 ppm and Nb values &lt;0·25 ppm, and Th is generally below the level of detection. Amphibole crystallization temperatures calculated from major elements range from ∼960 to 830 °C for all samples in the pluton; however, we do not observe significant differences in the range of crystallization temperatures between enriched (∼960–840 °C) and depleted groups (∼940–830 °C). Bulk-rock Sr and Nd isotopes are also remarkably homogeneous and show no apparent difference between enriched (εNdi = 0·1 to –0·1; 87Sr/86Sri = 0·70420–0·70413) and depleted groups (εNdi = 0·3 to –0·4; 87Sr/86Sri = 0·70424–0·70411). Calculated amphibole-equilibrium melt compositions using chemometric equations indicate that melts were highly fractionated (molar Mg# &lt;50), andesitic to dacitic in composition, and were much more evolved than bulk lower continental crust or primitive basalts and andesites predicted to have formed from hydrous melting of mantle-wedge peridotite beneath an arc. We suggest that melts originated from a common, isotopically homogeneous source beneath the Malaspina Pluton, and differences between enriched and depleted trace-element groups reflect varying contributions from subducted sediment-derived melt and sediment-derived fluid, respectively. Our data demonstrate that andesites and dacites were the dominant melts that intruded the lower crust, and their compositions mirror middle and upper bulk-continental crust estimates. Continental crust-like geochemical signatures were acquired in the source region from interaction between hydrous mantle-wedge melts and recycled subducted sediment rather than assimilation and/or remelting of pre-existing lower continental crust.
Trade-offs between risks of predation and starvation in larvae make the shelf break an optimal spawning location for Atlantic bluefin tuna
Authors: Shropshire Taylor A , Morey Steven L , Chassignet Eric P , Karnauskas Mandy , Coles Victoria J , Malca Estrella , Laiz-Carrión Raúl , Fiksen Øyvind , Reglero Patricia , Shiroza Akihiro , Quintanilla Hervas José M , Gerard Trika , Lamkin John T , Stukel Michael R 
Published: May 2021

Abstract
Atlantic bluefin tuna (ABT) (Thunnus thynnus) travel long distances to spawn in oligotrophic regions of the Gulf of Mexico (GoM) which suggests these regions offer some unique benefit to offspring survival. To better understand how larval survival varies within the GoM a spatially explicit, Lagrangian, individual-based model was developed that simulates dispersal and mortality of ABT early life stages within realistic predator and prey fields during the spawning periods from 1993 to 2012. The model estimates that starvation is the largest cumulative source of mortality associated with an early critical period. However, elevated predation on older larvae is identified as the main factor limiting survival to late postflexion. As a result, first-feeding larvae have higher survival on the shelf where food is abundant, whereas older larvae have higher survival in the open ocean with fewer predators, making the shelf break an optimal spawning area. The modeling framework developed in this study explicitly simulates both physical and biological factors that impact larval survival and hence could be used to support ecosystem based management efforts for ABT under current and future climate conditions.
Bound states of the Yukawa potential from hidden supersymmetry
Authors: Napsuciale M , Rodríguez S 
Published: May 2021

Abstract
We present a phenomenological study of the complete analytical solution to the bound eigenstates and eigenvalues of the Yukawa potential obtained previously using the hidden supersymmetry of the system and a systematic expansion of the Yukawa potential in terms of $\delta=a_{0}/D$, where $a_{0}$ is the Bohr radius and $D$ is the screening length. The eigenvalues, $\epsilon_{nl}(\delta)$, are given in the form of Taylor series in $\delta$ which can be systematically calculated to the desired order $\delta^{k}$. Coulomb $l$-degeneracy is broken by the screening effects and, for a given $n$, $\epsilon_{nl}(\delta)$ is larger for higher values of $l$, which causes the crossing of levels for $n\ge4$. The convergence radius of the Taylor series can be enlarged up to the critical values using the Padé approximants technique, which allows us to calculate the eigenvalues with high precision in the whole range of values of $\delta$ where bound states exist, and to reach a precise determination of the critical screening lengths, $\delta_{nl}$. Eigenstates have a form similar to the solutions of the Coulomb potential, with the associated Laguerre polynomials replaced by new polynomials of order $\delta^{k}$ with $r$-dependent coefficients which, in turn, are polynomials in $r$. In general we find sizable deviations from the Coulomb radial probabilities only for screening lengths close to their critical values. We use these solutions to find the squared absolute value at the origin of the wave function for $l=0$, and their derivatives for $l=1$, for the lowest states, as functions of $\delta$, which enter the phenomenology of dark matter bound states in dark gauge theories with a light dark mediator.
The biological responses and mechanisms of endothelial cells to magnesium alloy
Authors: Hou Zhe , Xiang Maolong , Chen Nuoya , Cai Xiao , Zhang Bo , Luo Rifang , Yang Li , Ma Xiaoyi , Zhou Lifeng , He Fugui , Yu Hongchi , Wang Yunbing 
Published: May 2021

AbstractDue to its good biocompatibility and degradability, magnesium alloy (Mg alloy) has shown great promise in cardiovascular stent applications. Rapid stent re-endothelialization is derived from migrated and adhered endothelial cells (ECs), which is an effective way to reduce late thrombosis and inhibit hyperplasia. However, fundamental questions regarding Mg alloy affecting migration and adhesion of ECs are not fully understood. Here, we evaluated the effects of Mg alloy on the ECs proliferation, adhesion and migration. A global gene expression profiling of ECs co-culturing with Mg alloy was conducted, and the adhesion- and migration-related genes were examined. We found that Mg alloy had no adverse effects on ECs viability but significantly affected ECs migration and adhesion. Co-cultured with Mg alloy extract, ECs showed contractive adhesion morphology and decreased motility, which was supported by the down-regulation of adhesion-related genes (Paxillin and Vinculin) and migration-related genes (RAC 1, Rho A and CDC 42). Accordingly, the re-endothelialization of Mg alloy stent was inhibited in vivo. Our results may provide new inspiration for improving the broad application of Mg alloy stents.
Journal citation reports and the definition of a predatory journal: The case of the Multidisciplinary Digital Publishing Institute (MDPI)
Authors: Oviedo-García M Ángeles 
Published: May 2021

AbstractThe extent to which predatory journals can harm scientific practice increases as the numbers of such journals expand, in so far as they undermine scientific integrity, quality, and credibility, especially if those journals leak into prestigious databases. Clarivate's Journal Citation Reports (JCR), a reference for the assessment of researchers and for grant-making decisions, is used as a standard whitelist, in so far as the selectivity of a JCR-indexed journal adds a legitimacy of sorts to the articles that the journal publishes. The Multidisciplinary Digital Publishing Institute (MDPI) had 53 journals ranked in the 2018 JCRs annual report. These journals are analysed, not only to contrast the formal criteria for the identification of predatory journals, but taking a step further, their background is also analysed with regard to self-citations and the source of those self-citations in 2018 and 2019. The results showed that the self-citation rates increased and was very much higher than those of the leading journals in the JCR category. Besides, an increasingly high rate of citations from other MDPI-journals was observed. The formal criteria together with the analysis of the citation patterns of the 53 journals under analysis all suggest they may be predatory journals. Hence, specific recommendations are given to researchers, educational institutions and prestigious databases advising them to review their working relations with those sorts of journals.
Society of Behavioral Medicine (SBM) Position Statement: increase access to mental health services due to COVID-19-related parent and family stress
Authors: Bean Melanie K , Adams Elizabeth L , Buscemi Joanna , Ford Sabrina , Wischenka Danielle , Behrman Pam , Wilson Dawn K , Gladstone Tracy R G , Fitzgibbon Marian L 
Published: May 2021

Abstract
COVID-19 has caused drastic increases in family stress contributing to deleterious social and emotional ramifications. Before COVID-19, millions of Americans lacked access to mental health resources, and now in the midst of a global pandemic, resources are more limited in times of greater need. In March 2020, the Coronavirus Aid, Relief, and Economic Security (CARES) Act provided funding for mental health reforms; yet many barriers remained to receiving sufficient care. In February 2021, the Society of Behavioral Medicine recommended federal legislators expand Community Behavioral Healthcare Centers, increase funding for Federally Qualified Healthcare Centers and School Based Health Centers, incentivize providers to accept Medicaid, and institute more statewide licensing flexibilities to expand the reach of mental health care. In March 2021, the American Rescue Plan was signed into law and provided an additional ~$4 billion in funding for community mental health services, implementing substance abuse prevention and treatment programs, increasing the behavioral health workforce, promoting behavioral telehealth within primary care, increasing school-based mental health services, implementing suicide prevention programs, and improving services for traumatized families. This significant investment in parents and children’s mental health is a tremendous step in the right direction and provides reassurance that relief is underway. Ongoing surveillance of the programmatic and clinical outcomes that result from these new policy reforms will be important for identifying areas that may need continual support as our nation recovers from COVID-19.