bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tidal disruption events in the first billion years of a galaxy
Authors: Pfister Hugo , Dai Jane Lixin , Volonteri Marta , Auchettl Katie , Trebitsch Maxime , Ramirez-Ruiz Enrico 
Published: November 2020

ABSTRACT
Accretion of stars on massive black holes (MBHs) can feed MBHs and generate tidal disruption events (TDEs). We introduce a new physically motivated model to self-consistently treat TDEs in cosmological simulations, and apply it to the assembly of a galaxy with final mass $3\times 10^{10}\, \mathrm{M}_{\odot }$ at z = 6. This galaxy exhibits a TDE rate of $\sim 10^{-5}\, \mathrm{yr}^{-1}$, consistent with local observations but already in place when the Universe was one billion year old. A fraction of the disrupted stars participate in the growth of MBHs, dominating it until the MBH reaches mass $\sim 5 \times 10^5 \, \mathrm{M}_{\odot }$, but their contribution then becomes negligible compared to gas. TDEs could be a viable mechanism to grow light MBH seeds, but fewer TDEs are expected when the MBH becomes sufficiently massive to reach the luminosity of, and be detected as, an active galactic nucleus. Galaxy mergers bring multiple MBHs in the galaxy, resulting in an enhancement of the global TDE rate in the galaxy by ∼1 order of magnitude during $100\, \mathrm{Myr}$ around mergers. This enhancement is not on the central MBH, but caused by the presence of MBHs in the infalling galaxies. This is the first self-consistent study of TDEs in a cosmological environment and highlights that accretion of stars and TDEs are a natural process occurring in a Milky Way-mass galaxy at early cosmic times.
Explosion energies for core-collapse supernovae I: analytic, spherically symmetric solutions
Authors: Gogilashvili Mariam , Murphy Jeremiah W , Mabanta Quintin 
Published: November 2020

ABSTRACT
Recent multidimensional simulations of core-collapse supernovae are producing successful explosions and explosion-energy predictions. In general, the explosion-energy evolution is monotonic and relatively smooth, suggesting a possible analytic solution. We derive analytic solutions for the expansion of the gain region under the following assumptions: spherical symmetry, one-zone shell, and powered by neutrinos and α particle recombination. We consider two hypotheses: (I) explosion energy is powered by neutrinos and α recombination and (II) explosion energy is powered by neutrinos alone. Under these assumptions, we derive the fundamental dimensionless parameters and analytic scalings. For the neutrino-only hypothesis (II), the asymptotic explosion energy scales as $E_{\infty } \approx 1.5 M_\mathrm{ g}\nu _0^2 \eta ^{2/3}$, where Mg is the gain mass, $\nu _0$ is the free-fall velocity at the shock, and η is a ratio of the heating and dynamical time-scales. Including both neutrinos and recombination (hypothesis I), the asymptotic explosion energy is $E_{\infty } \approx M_g \nu _0^2 (1.5\eta ^{2/3} + \beta f(\rho _0))$, where β is the dimensionless recombination parameter. We use Bayesian inference to fit these analytic models to simulations. Both hypotheses fit the simulations of the lowest progenitor masses that tend to explode spherically. The fits do not prefer hypothesis I or II; however, prior investigations suggest that α recombination is important. As expected, neither hypothesis fits the higher mass simulations that exhibit aspherical explosions. In summary, this explosion energy theory is consistent with the spherical explosions of low progenitor masses; the inconsistency with higher progenitor-mass simulations suggests that a theory for them must include aspherical dynamics.
Getting the model right: an information criterion for spectroscopy
Authors: Webb John K , Lee Chung-Chi , Carswell Robert F , Milaković Dinko 
Published: November 2020

ABSTRACT
Robust model-fitting to spectroscopic transitions is a requirement across many fields of science. The corrected Akaike and Bayesian information criteria (AICc and BIC) are most frequently used to select the optimal number of fitting parameters. In general, AICc modelling is thought to overfit (too many model parameters) and BIC underfits. For spectroscopic modelling, both AICc and BIC lack in two important respects: (a) no penalty distinction is made according to line strength such that parameters of weak lines close to the detection threshold are treated with equal importance as strong lines and (b) no account is taken of the way in which a narrow spectral line impacts only on a very small section of the overall data. In this paper, we introduce a new information criterion that addresses these shortcomings, the Spectral Information Criterion (SpIC). Spectral simulations are used to compare performances. The main findings are (i) SpIC clearly outperforms AICc for high signal-to-noise data, (ii) SpIC and AICc work equally well for lower signal-to-noise data, although SpIC achieves this with fewer parameters, and (iii) BIC does not perform well (for this application) and should be avoided. The new method should be of broader applicability (beyond spectroscopy), wherever different model parameters influence separated small ranges within a larger data set and/or have widely varying sensitivities.
In search of radio emission from exoplanets: GMRT observations of the binary system HD 41004
Authors: Narang Mayank , Manoj P , Ishwara Chandra C H , Lazio Joseph , Henning Thomas , Tamura Motohide , Mathew Blesson , Ujwal Nitish , Mandal Pritha 
Published: November 2020

ABSTRACT
This paper reports Giant Metrewave Radio Telescope (GMRT) observations of the binary system HD 41004 that are among the deepest images ever obtained at 150 and 400 MHz in the search for radio emission from exoplanets. The HD 41004 binary system consists of a K1 V primary star and an M2 V secondary; both stars are host to a massive planet or brown dwarf. Analogous to planets in our Solar system that emit at radio wavelengths due to their strong magnetic fields, one or both of the planet or brown dwarf in the HD 41004 binary system are also thought to be sources of radio emission. Various models predict HD 41004Bb to have one of the largest expected flux densities at 150 MHz. The observations at 150 MHz cover almost the entire orbital period of HD 41004Bb, and about $20{{\ \rm per\ cent}}$ of the orbit is covered at 400 MHz. We do not detect radio emission, setting 3σ limits of 1.8 mJy at 150 MHz and 0.12 mJy at 400 MHz. We also discuss some of the possible reasons why no radio emission was detected from the HD 41004 binary system.
Measuring individual masses of binary white dwarfs with space-based gravitational-wave interferometers
Authors: Wolz Anna , Yagi Kent , Anderson Nick , Taylor Andrew J 
Published: November 2020

ABSTRACT
Unlike gravitational waves from merging black holes and neutron stars that chirp significantly over the observational period of ground-based detectors, gravitational waves from binary white dwarfs are almost monochromatic. This makes it extremely challenging to measure their individual masses. Here, we take a novel approach of using finite-size effects and applying certain universal relations to measure individual masses of binary white dwarfs using Laser Interferometer Space Antenna. We found quasi-universal relations among the mass, moment of inertia, and tidal deformability of a white dwarf that do not depend sensitively on the white dwarf composition. These relations allow us to rewrite the moments of inertia and tidal deformabilities in the waveform in terms of the masses. We then carried out a Fisher analysis to estimate how accurately one can measure the individual masses from the chirp mass and finite-size measurements. We found that the individual white dwarf masses can be measured with LISA for a 4-yr observation if the initial frequency is high enough (∼0.02 Hz) and either the binary separation is small (∼1 kpc) or the masses are relatively large (m ≳ 0.8 M⊙). This opens a new possibility of measuring individual masses of binary white dwarfs with space-based interferometers.
Further evidence to support a tidal disruption event in the changing-look AGN SDSS J0159
Authors: Zhang Xue-Guang 
Published: November 2020

ABSTRACT
In this Letter, we report further evidence to support a tidal disruption event (TDE) in the known changing-look AGN SDSS J0159, through the unique variabilities of asymmetric broad Hα: broader but redder in 2010 than in 2000. If we accept that broad Hα emission regions are tightly related to accreting debris in a central TDE, the well-known relativistic accretion disc origination can be applied to explain the asymmetric broad Hα variabilities in SDSS J0159 well. Moreover, the model-determined broad Hα emission regions have sizes that do not follow the empirical R−L relation valid in normal broad-line active galactic nuclei (AGNs), but have locations basically similar to the regions of accreting debris from a central TDE in SDSS J0159, indicating tight connections between the broad Hα emission material and central TDE debris. Therefore, the explanation of asymmetric broad Hα variabilities through a relativistic accretion disc origination provides further clues to support a central TDE in SDSS J0159.
Alignment free identification of clones in B cell receptor repertoires
Authors: Lindenbaum Ofir , Nouri Nima , Kluger Yuval , Kleinstein Steven H 
Published: November 2020

AbstractFollowing antigenic challenge, activated B cells rapidly expand and undergo somatic hypermutation, yielding groups of clonally related B cells with diversified immunoglobulin receptors. Inference of clonal relationships based on the receptor sequence is an essential step in many adaptive immune receptor repertoire sequencing studies. These relationships are typically identified by a multi-step process that involves: (i) grouping sequences based on shared V and J gene assignments, and junction lengths and (ii) clustering these sequences using a junction-based distance. However, this approach is sensitive to the initial gene assignments, which are error-prone, and fails to identify clonal relatives whose junction length has changed through accumulation of indels. Through defining a translation-invariant feature space in which we cluster the sequences, we develop an alignment free clonal identification method that does not require gene assignments and is not restricted to a fixed junction length. This alignment free approach has higher sensitivity compared to a typical junction-based distance method without loss of specificity and PPV. While the alignment free procedure identifies clones that are broadly consistent with the junction-based distance method, it also identifies clones with characteristics (multiple V or J gene assignments or junction lengths) that are not detectable with the junction-based distance method.
Efficacy and Safety of Eravacycline in Obese Patients: A Post Hoc Analysis of Pooled Data From the IGNITE1 and IGNITE4 Clinical Trials
Authors: Asempa Tomefa E , Izmailyan Sergey , Lawrence Kenneth , Nicolau David P 
Published: November 2020

AbstractBackgroundThe increasing prevalence of obesity worldwide merits an examination of the efficacy and safety profiles of agents dosed by weight.MethodsData for patients (n = 1037) were obtained from the pooled IGNITE1 and IGNITE4 randomized double-blind trials in which patients with complicated intra-abdominal infections received eravacycline 1 mg/kg (actual body weight [ABW]) every 12 hours or comparator (ertapenem 1 g every 24 hours or meropenem 1 g every 8 hours) intravenously. This post hoc analysis evaluated clinical cure rates, adverse events, and drug discontinuation rates stratified by body mass index (BMI) categories of BMI &gt;40 kg/m2 (Obese, Class III), BMI 35–39.9 kg/m2 (Obese, Class II), BMI 30–34.9 kg/m2 (Obese, Class I), BMI 25–29.9 kg/m2 (Overweight), BMI 18.5–24.9 kg/m2 (Healthy weight), and BMI &lt;18.5 kg/m2 (Underweight).ResultsClinical cure rates were high across BMI categories and ranged from 82% to 94% in the eravacycline group and 88.5%–100% in the comparator group. Similar cure rates were observed among eravacycline-treated healthy weight (126/134; 94%), overweight (127/146; 87%), and obese (BMI ≥30 kg/m2; 110/129; 85.3%) patients. In the comparator group, a similar proportion of patients demonstrated clinical response (healthy weight [132/145; 91%], overweight [130/144; 90.3%], and obese [115/129; 89.1%]). Of the treatment-emergent adverse events that occurred in eravacycline-treated obese patients, a larger proportion were gastrointestinal-related (ie, nausea and vomiting); however, discontinuation rates were low and similar between eravacycline and carbapenems.ConclusionsThis post hoc analysis demonstrates the therapeutic utility and acceptable safety profile of eravacycline dosed by ABW in obese patients (BMI ≥30 kg/m2).
Isolated Cerebral Mucormycosis in Immunocompetent Adults who Inject Drugs: Case Reports and Systematic Review of the Literature
Authors: Meyerowitz Eric A , Sanchez Sarimer , Mansour Michael K , Triant Virginia A , Goldberg Marcia B 
Published: November 2020

Abstract

Background
Mucormycosis involves life-threatening rapidly progressive angioinvasion with infiltration across tissue planes, resulting in necrosis and thrombosis, most commonly seen in the setting of immunocompromised states. We describe 2 cases of isolated cerebral mucormycosis in immunocompetent adults and describe this syndrome in detail in the context of a systemic literature review.

Methods
Using the criteria (1) isolated cerebral disease, (2) mucormycosis (by polymerase chain reaction, culture, or pathology), and (3) affected an immunocompetent individual, we identified 53 additional cases from 1969 to 2020.

Results
Of these 55 cases, ~60% occurred in men, &gt;70% were in patients under age 35, 92% were associated with intravenous drug use, and &gt;85% had infection centered in the basal ganglia. Many presented with cranial nerve deficits, headache, focal weakness, or altered mental status.

Conclusions
No patient survived without amphotericin, and steroid administration was associated with worse outcomes. Given the current opioid crisis, this syndrome may be seen more frequently.
Poverty and survival from COVID-19 in Mexico
Authors: Millán-Guerrero Rebeca Olivia , Caballero-Hoyos Ramiro , Monárrez-Espino Joel 
Published: November 2020

Abstract

Background
Recent evidence points to the relevance of poverty and inequality as factors affecting the spread and mortality of the COVID-19 pandemic in Latin America. This study aimed to determine whether COVID-19 patients living in Mexican municipalities with high levels of poverty have a lower survival compared with those living in municipalities with low levels.

Methods
Retrospective cohort study. Secondary data was used to define the exposure (multidimensional poverty level) and outcome (survival time) among patients diagnosed with COVID-19 between 27 February and 1 July 2020. Crude and adjusted hazard ratios (HR) from Cox regression were computed.

Results
Nearly 250 000 COVID-19 patients were included. Mortality was 12.3% reaching 59.3% in patients with ≥1 comorbidities. Multivariate survival analyses revealed that individuals living in municipalities with extreme poverty had 9% higher risk of dying at any given time proportionally to those living in municipalities classified as not poor (HR 1.09; 95% CI 1.06–1.12). The survival gap widened with the follow-up time up to the third to fourth weeks after diagnosis.

Conclusion
Evidence suggests that the poorest population groups have a lower survival from COVID-19. Thus, combating extreme poverty should be a central preventive strategy.
Equilibrium of Two Rods in Contact Under Pressure
Authors: Turzi S , Zoppello M , Ambrosi D 
Published: November 2020

Summary
We study the equilibrium of a mechanical system composed by two rods that bend under the action of a pressure difference; they have one fixed endpoint and are partially in contact. This system can be viewed as a bi-valve made by two smooth leaflets that lean on each other. We obtain the balance equations of the mechanical system exploiting the principle of virtual work and the contact point is identified by a jump condition. The problem can be simplified exploiting a first integral. In the case of quadratic energy, another first integral exists: its peculiarity is discussed and a further reduction of the equations is carried out. Numerical integration of the differential system shows how the shape of the beams and the position of the contact point depend on the applied pressure. For small pressure, an asymptotic expansion in a small parameter allows us to find an approximate solutions of polynomial form which is in surprisingly good agreement with the solution of the original system of equations, even beyond the expected range of validity. Finally, the asymptotics predicts a value of the pressure that separates the contact from the no-contact regime of the beams that compares very well with the one numerically evaluated.
EVALUATION OF ORGAN DOSE BASED ON PATIENT DATA IN EAST ASIAN DESCENT PEDIATRIC HEAD CT EXAMINATIONS
Authors: Kawamoto Keishin , Fukushima Yasuhiro , Matsuda Akira , Nakata Manabu 
Published: November 2020

Abstract
The purpose of this study was to investigate other indices estimating absorbed dose for eye lens and brain, using clinical images of East Asian pediatric patients. We simulated head computed tomography (CT ) examinations in 104 pediatric patients. Effective diameter (deff) and water equivalent diameter (dw) were measured on clinical images. Various size metrics and age were compared with absorbed dose normalised by CTDIvol (nD). The nD was estimated for eye and brain. The nD tended to decrease with advancing age. R2 between age and nD were 0.38 and 0.31 for eye and brain, respectively. Increasing head diameters decreased each nD. R2 between deff and dw, and nD were 0.20–0.24 and 0.51–0.53 for eye and brain, respectively. Head sizes allowed us to estimate absorbed dose in brain CT on East Asian pediatric patients. Scanning parameters for pediatric head CT may need to be based on individual patient information.
Inhibition of Acetyl-CoA Carboxylase Causes Malformations in Rats and Rabbits: Comparison of Mammalian Findings and Alternative Assays
Authors: Catlin Natasha R , Bowman Christopher J , Campion Sarah N , Davenport Scott D , Esler William P , Kumpf Steven W , Lewis Elise M , Nowland William S , Ross Trenton T , Stedman Donald S , Stethem Christine , Cappon Gregg D 
Published: November 2020

Abstract
Acetyl-CoA carboxylase (ACC) is an enzyme within the de novo lipogenesis (DNL) pathway and plays a role in regulating lipid metabolism. Pharmacologic ACC inhibition has been an area of interest for multiple potential indications including oncology, acne vulgaris, metabolic diseases such as type 2 diabetes mellitus, and nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. A critical role for ACC in de novo synthesis of long-chain fatty acids during fetal development has been demonstrated in studies in mice lacking Acc1, where the absence of Acc1 results in early embryonic lethality. Following positive predictions of developmental toxicity in the alternative in vitro assays (positive in murine embryonic stem cell [mESC] assay and rat whole embryo culture, but negative in zebrafish), developmental toxicity (growth retardation and dysmorphogenesis associated with disrupted midline fusion) was observed with the oral administration of the dual ACC1 and 2 inhibitors, PF-05175157, in Sprague Dawley rats and New Zealand White rabbits. The results of these studies are presented here to make comparisons across the assays, as well as mechanistic insights from the mESC assay demonstrating high ACC expression in the mESC and that ACC-induced developmental toxicity can be rescued with palmitic acid providing supportive evidence for DNL pathway inhibition as the underlying mechanism. Ultimately, while the battery of alternative approaches and weight-of-evidence case were useful for hazard identification, the embryo-fetal development studies were necessary to inform the risk assessment on the adverse fetal response, as malformations and/or embryo-fetal lethality were limited to doses that caused near-complete inhibition of DNL.
Specific leaf metabolic changes that underlie adjustment of osmotic potential in response to drought by four Quercus species
Authors: Aranda Ismael , Cadahía Estrella , Fernández de Simón Brígida 
Published: November 2020

Abstract
Osmotic adjustment is almost ubiquitous as a mechanism of response to drought in many forest species. Recognized as an important mechanism of increasing turgor under water stress, the metabolic basis for osmotic adjustment has been described in only a few species. We set an experiment with four species of the genus Quercus ranked according to drought tolerance and leaf habit from evergreen to broad-leaved deciduous. A cycle of watering deprivation was imposed on seedlings, resulting in well-watered (WW) and water-stressed (WS) treatments, and their water relations were assessed from pressure–volume curves. Leaf predawn water potential (Ψpd) significantly decreased in WS seedlings, which was followed by a drop in leaf osmotic potential at full turgor (Ψπ100). The lowest values of Ψπ100 followed the ranking of decreasing drought tolerance: Quercus ilex L. &lt; Quercus faginea Lam. &lt; Quercus pyrenaica Willd. &lt; Quercus petraea Matt. Liebl. The leaf osmotic potential at the turgor loss point (ΨTLP) followed the same pattern as Ψπ100 across species and treatments. The pool of carbohydrates, some organic acids and cyclitols were the main osmolytes explaining osmotic potential across species, likewise to the osmotic adjustment assessed from the decrease in leaf Ψπ100 between WW and WS seedlings. Amino acids were very responsive to WS, particularly γ-aminobutyric acid in Q. pyrenaica, but made a relatively minor contribution to osmotic potential compared with other groups of compounds. In contrast, the cyclitol proto-quercitol made a prominent contribution to the changes in osmotic potential regardless of watering treatment or species. However, different metabolites, such as quinic acid, played a more important role in osmotic adjustment in Q. ilex, distinguishing it from the other species studied. In conclusion, while osmotic adjustment was present in all four Quercus species, the molecular processes underpinning this response differed according to their phylogenetic history and specific ecology.
Adaptation of advanced clinical virology assays from HIV-1 to SARS-CoV-2
Authors: McCormick Kevin D. , Mellors John W. , Jacobs Jana L. 
Published: November 2020

Purpose of review
In response to the HIV–AIDS pandemic, great strides have been made in developing molecular methods that accurately quantify nucleic acid products of HIV-1 at different stages of viral replication and to assess HIV-1 sequence diversity and its effect on susceptibility to small molecule inhibitors and neutralizing antibodies. Here, we review how knowledge gained from these approaches, including viral RNA quantification and sequence analyses, have been rapidly applied to study SARS-CoV-2 and the COVID-19 pandemic.

Recent findings
Recent studies have shown detection of SARS-CoV-2 RNA in blood of infected individuals by reverse transcriptase PCR (RT-PCR); and, as in HIV-1 infection, there is growing evidence that the level of viral RNA in plasma may be related to COVID disease severity. Unlike HIV-1, SARS-CoV-2 sequences are highly conserved limiting SARS-CoV-2 sequencing applications to investigating interpatient genetic diversity for phylogenetic analysis. Sensitive sequencing technologies, originally developed for HIV-1, will be needed to investigate intrapatient SARS-CoV-2 genetic variation in response to antiviral therapeutics and vaccines.

Summary
Methods used for HIV-1 have been rapidly applied to SARS-CoV-2/COVID-19 to understand pathogenesis and prognosis. Further application of such methods should improve precision of therapy and outcome.