cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Theoretical methods for excitonic physics in two-dimensional materials
Creators: name: Quintela, M. F. C. Martins
name: Henriques, J. C. G.
name: Peres, N. M. R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this tutorial we introduce the reader to several theoretical methods of determining the exciton wave functions and the corresponding eigenenergies. The methods covered are either analytical, semi-analytical, or numeric. We make explicit all the details associated with the different methods, thus allowing newcomers to do research on their own, without experiencing a steep learning curve. The tutorial starts with a variational method and ends with a simple semi-analytical approach to solve the Bethe-Salpeter equation in two-dimensional (2D) gapped materials. For the first methods addressed in this tutorial, we focus on a single layer of hexagonal Boron Nitride (hBN) and of transition metal dichalcogenide (TMD), as these are exemplary materials in the field of 2D excitons. For explaining the Bethe- Salpeter method we choose the biased bilayer graphene, which presents a tunnable band gap. The system has the right amount of complexity (without being excessive). This allows the presentation of the solution of the Bethe-Salpeter equation in a context that can be easily generalized to more complex systems or to apply it to simpler models.
description: 31 pages, 111 references; we welcome comments and requests to add additional references; several changes relatively to version V1
Methodology for estimating the magnetic Prandtl number and application to solar surface small-scale dynamo simulations
Creators: name: Riva, Fabio
name: Steiner, Oskar
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. A crucial step in the numerical investigation of small-scale dynamos in the solar atmosphere consists of an accurate determination of the magnetic Prandtl number, Prm, stemming from radiative magneto-hydrodynamic (MHD) simulations. Aims. The aims are to provide a reliable methodology for estimating the effective Reynolds and magnetic Reynolds numbers, Re and Rem, and their ratio Prm=Rem/Re (the magnetic Prandlt number), that characterise MHD simulations and to categorise small-scale dynamo simulations in terms of these dimensionless parameters. Methods. The methodology proposed for computing Re and Rem is based on the method of projection on proper elements and it relies on a post-processing step carried out using higher order accurate numerical operators than the ones in the simulation code. A number of radiative MHD simulations with different effective viscosities and plasma resistivities were carried out with the CO5BOLD code, and the resulting growth rate of the magnetic energy and saturated magnetic field strengths were characterised in terms of Re and Rem. Results. Overall, the proposed methodology provides a solid estimate of the dissipation coefficients affecting the momentum and induction equations of MHD simulation codes, and consequently also a reliable evaluation of the magnetic Prandtl number characterising the numerical results. Additionally, it is found that small-scale dynamos are active and can amplify a small seed magnetic field up to significant values in CO5BOLD simulations with a grid spacing smaller than h=12 km, even at Prm=0.65. However, it is also evident that it is difficult to categorise dynamo simulations in terms of Prm alone, because it is not only important to estimate the amplitude of the dissipation coefficients, but also at which scales energy dissipation takes place.
description: 12 pages, 6 figures, ready for the production stage in A&A
Does Quality Matter for Citedness? A comparison with para-textual factors and over time
Creators: name: Bornmann, Lutz
name: Loet Leydesdorff
Publisher: name: figshare
Year: 2014
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: Using (binomial) regression analysis, we run models using citation windows of one to ten years with both annual citation and cumulative citations as dependent variables, and with both bibliometric and quality indicators (judgments of peers) as independent variables. The bibliometric variables are the journal impact factor (JIF) of the publication medium, the numbers of authors and pages, and the statistical citedness of the references used within the paper. We find that the JIF and the number of authors have a larger influence on the citation impact of a publication than the quality (measured by judgments of peers). However, the number of pages and the quality of the references are less influential. The influence of JIF and the number of authors peaks after three years and then declines, but remains higher than the influence of quality even after ten years. These results call into question a discrepancy between the algorithmically based indicators and the qualitative judgments by experts. The latter seems less predictive for future citation than a combination of algorithmic constructs.
Asyncval: A Toolkit for Asynchronously Validating Dense Retriever Checkpoints during Training
Creators: name: Zhuang, Shengyao
name: Zuccon, Guido
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: The process of model checkpoint validation refers to the evaluation of the performance of a model checkpoint executed on a held-out portion of the training data while learning the hyperparameters of the model, and is used to avoid over-fitting and determine when the model has converged so as to stop training. A simple and efficient strategy to validate deep learning checkpoints is the addition of validation loops to execute during training. However, the validation of dense retrievers (DR) checkpoints is not as trivial -- and the addition of validation loops is not efficient. This is because, in order to accurately evaluate the performance of a DR checkpoint, the whole document corpus needs to be encoded into vectors using the current checkpoint before any actual retrieval operation for checkpoint validation can be performed. This corpus encoding process can be very time-consuming if the document corpus contains millions of documents (e.g., 8.8m for MS MARCO and 21m for Natural Questions). Thus, a naive use of validation loops during training will significantly increase training time. To address this issue, in this demo paper, we propose Asyncval: a Python-based toolkit for efficiently validating DR checkpoints during training. Instead of pausing the training loop for validating DR checkpoints, Asyncval decouples the validation loop from the training loop, uses another GPU to automatically validate new DR checkpoints and thus permits to perform validation asynchronously from training. Asyncval also implements a range of different corpus subset sampling strategies for validating DR checkpoints; these strategies allow to further speed up the validation process. We provide an investigation of these methods in terms of their impact on validation time and validation fidelity. Asyncval is made available as an open-source project at https://github.com/ielab/asyncval.
description: Demo paper, accepted at SIGIR2022
Four-body system of ${}^4\mathrm{He}$ atoms: Dimer-dimer scattering
Creators: name: Deltuva, A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The strong short-range repulsion, characteristic to realistic interatomic potentials, complicates the description of weakly-bound few-body systems such as those of \He atoms. The present work proposes an approach for solving this problem and applies it to a realistic system of four ${}^4\mathrm{He}$ atoms. The potential is gradually softened such that rigorous four-body equations for bound and scattering tates can be accurately solved in the momentum-space framework, and the results are extrapolated back to the limit of the original potential. Linear correlations between three- and four body quantities are observed, and the accuracy of the procedure is improved by extrapolating in one of the three-body quantities. Results for the ${}^4\mathrm{He}$ tetramer ground and excited state binding energies and atom-trimer scattering agree well with at least some of earlier determinations and shed light on the existing disagreements. An additional case of the Phillips correlation line is established for the dimer-dimer scattering length. The trimer production rate via the ultracold two-dimer collisions is estimated, it exhibits significant finite-range effects despite the weak binding of the dimer.
description: 6+ pages, 4 figures
title: Istanbul, ville durable ?
Publisher: name: Institut Français d'Études Anatoliennes Georges Dumézil
Year: 2015

description: Istanbul, ville durable? Questionnements, débats, expériences de terrain et perspectives croisées  Propos   On peut commencer par une question naïve :   au-delà des incantations souvent intéressées des politiques et de   certains segments de la “société civile”, la plus grande agglomération   du pourtour méditerranéen se cartactérise-t-elle par un mode de   développement durable? Plus que nombre de questions qui occupent   l’agenda de recherche, cette question nous semble centrale. L’OUI se   propose, en relation avec ses partenaires, d’apporter quelques éléments   de réponse et de réflexion. L’idée est à la fois de prendre connaissance   des initiatives prises à Istanbul et de mettre en relation des acteurs   convaincus par les mêmes nécessités. En effet, l’urgence d’une action   plus intégrée et territorialisée est grande, comme les ino
title: Politiques énergétiques métropolitaines : le cas des villes turques
Publisher: name: Institut Français d'Études Anatoliennes Georges Dumézil
Year: 2015

description: PROGRAMME  Séminaire organisé par l'Institut français d’études anatoliennes, l'Université de Galatasaray et Environnement Ville Société, CNRS-Université de Lyon  Organisateurs : Eric Verdeil (EVS CNRS-Lyon University) – Jean-François Pérouse (Toulouse-II University/Galatasaray U.)  Avec le soutien de la Région Rhône Alpes (Coopera 2012) et l'aide du LATTS (ENPC-Paris Est University)  Lieu: Institut français d’études anatoliennes - Palais de France - Nur-i Ziya Sokak, 10 P.K.54 - TR-34433 - Beyoğlu - Istanbul  Date : 29th May 2012, 9 :30 – 17:00.  Une visite sur le terrain est prévue le 30 mai.  http://calenda.revues.org/nouvelle23382.html  Langue : les conférenciers interviendront en anglais ou donneront un résumé en anglais de leur communication.       séminaire à l'Institut français d'études anatoliennes, co-organisé par Eric Verdeil (U
Does Quality and Content Matter for Citedness? A comparison with para-textual factors and over time
Creators: name: Bornmann, Lutz
name: Loet Leydesdorff
Publisher: name: figshare
Year: 2015
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: Using (binomial) regression analysis, we run models using citation windows of one to ten years with both annual citation and cumulative citations as dependent variables, and with both bibliometric and quality indicators (judgments of peers) as independent variables. The bibliometric variables are the journal impact factor (JIF) of the publication medium, the numbers of authors and pages, and the statistical citedness of the references used within the paper. We find that the JIF have a larger influence on the citation impact of a publication than the quality (measured by judgments of peers). However, the number of pages and the quality of the references are less influential. The influence of JIF peaks after three years and then declines (in most regression analyses), but remains higher than the influence of quality judgments even after ten years. These results call into question a discrepancy between the algorithmically based indicators and the qualitative judgments by experts. The latter seems less predictive for future citation than a combination of algorithmic constructs. The results of this study can contribute to the empirical specification of the relevance of a normative versus a constructivist theory of citation.
Non-iterative finite amplitude methods for E1 and M1 giant resonances
Creators: name: Sasaki, Hirokazu
name: Kawano, Toshihiko
name: Stetcu, Ionel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The finite amplitude method (FAM) is a very efficient approach for solving the fully self-consistent random-phase approximation (RPA) equations. We use FAM to rederive the RPA matrices for general Skyrme-like functionals, calculate the electric dipole (E1) and the magnetic dipole (M1) giant resonances, and compare the results with available experimental and evaluated data. For the E1 transitions in heavy nuclei, the calculations reproduce well the resonance energy of the photoabsorption cross sections. In the case of M1 transitions, we show that the residual interaction does not affect the transition strength of double-magic nuclei, which suggests that the spin terms in the Skyrme force currently neglected in the present computation could improve the agreement between FAM and experimental data.
description: 15 pages, 6 figures
Does Quality and Content Matter for Citedness? A comparison with para-textual factors and over time
Creators: name: Bornmann, Lutz
name: Loet Leydesdorff
Publisher: name: figshare
Year: 2015
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: Using (binomial) regression analysis, we run models using citation windows of one to ten years with both annual citation and cumulative citations as dependent variables, and with both bibliometric and quality indicators (judgments of peers) as independent variables. The bibliometric variables are the journal impact factor (JIF) of the publication medium, the numbers of authors and pages, and the statistical citedness of the references used within the paper. We find that the JIF have a larger influence on the citation impact of a publication than the quality (measured by judgments of peers). However, the number of pages and the quality of the references are less influential. The influence of JIF peaks after three years and then declines (in most regression analyses), but remains higher than the influence of quality judgments even after ten years. These results call into question a discrepancy between the algorithmically based indicators and the qualitative judgments by experts. The latter seems less predictive for future citation than a combination of algorithmic constructs.
Forming planets around stars with non-solar elemental composition
Creators: name: Jorge, D. M.
name: Kamp, I. E. E.
name: Waters, L. B. F. M.
name: Woitke, P.
name: Spaargaren, R. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Stars in the solar neighbourhood have refractory element ratios slightly different from the Sun. It is unclear how much the condensation of solids and thus the composition of planets forming around these stars is affected. We aim to understand the impact of changing the ratios of refractory elements Mg, Si, and Fe within the range observed in solar type stars within 150~pc on the composition of planets forming around them. We use the GGchem code to simulate the condensation of solids in protoplanetary disks with a Minimum Mass Solar Nebula around main sequence G-type stars in the Solar neighbourhood. We extract the stellar elemental composition from the Hypatia database. We find that a lower Mg/Si ratio shifts the condensation sequence from forsterite (Mg$_2$SiO$_4$) and SiO to enstatite (MgSiO$_3$) and quartz (SiO$_2$); a lower Fe/S ratio leads to the formation of FeS and FeS$_2$ and little or no Fe-bearing silicates. Ratios of refractory elements translate directly from the gas phase to the condensed phase for $T\,
description: Accepted for publication in A&A
RDM Green Shoots Project Report: "Research data management: Where software meets data"
Creators: name: Jacobs, Christian
name: Avdis, Alexandros
name: Gorman, Gerard
name: Piggott, Matthew
Publisher: name: figshare
Year: 2014
Subjects: subject: Computer Software
subject: FOS: Computer and information sciences

description: A report for an RDM Green Shoots project at Imperial College London, entitled "Research data management: Where software meets data".
Generalised point vortices on a plane
Creators: name: Galajinsky, Anton
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: A three-vortex system on a plane is known to be minimally superintegrable in the Liouville sense. In this work, integrable generalisations of the three-vortex planar model, which involve root vectors of simple Lie algebras, are proposed. It is shown that a generalised system, which is governed by a positive definite Hamiltonian, admits a natural integrable extension by spin degrees of freedom. It is emphasised that the n-vortex planar model and plenty of its generalisations enjoy the nonrelativistic scale invariance, which gives room for possible holographic applications.
description: 11 pages
CHEMOUT: CHEMical complexity in star-forming regions of the OUTer Galaxy. I. Organic molecules and tracers of star-formation activity
Creators: name: Fontani, F.
name: Colzi, L.
name: Bizzocchi, L.
name: Rivilla, V. M.
name: Elia, D.
name: Beltrán, M. T.
name: Caselli, P.
name: Magrini, L.
name: Sánchez-Monge, A.
name: Testi, L.
name: Romano, D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The outer Galaxy is an environment with metallicity lower than the Solar one. Because of this, the formation and survival of molecules in star-forming regions located in the inner and outer Galaxy is expected to be different. To gain understanding on how chemistry changes throughout the Milky Way, it is crucial to observe outer Galaxy star-forming regions to constrain models adapted for lower metallicity environments. In this paper we present a new observational project: chemical complexity in star-forming regions of the outer Galaxy (CHEMOUT). The goal is to unveil the chemical composition in 35 dense molecular clouds associated with star-forming regions of the outer Galaxy through observations obtained with the IRAM 30m telescope. In this first paper, we present the sample, and report the detection at 3~mm of simple organic species HCO+, H13CO+, HCN, c-C3H2, HCO, C4H, and HCS+, of the complex hydrocarbon CH3CCH, and of SiO, CCS and SO. From c-C3H2, we estimate new kinematic heliocentric and Galactocentric distances based on an updated rotation curve of the Galaxy. The detection of the molecular tracers does not seem to have a clear dependence on the Galactocentric distance. We also analyse the HCO+ line profiles. We find high velocity wings in ~71% of the targets, and their occurrence does not depend on the Galactocentric distance. Our results, confirmed by a statistical analysis, show that the presence of organic molecules and tracers of protostellar activity is ubiquitous in the low-metallicity environment of the outer Galaxy. Based on this, and on the additional evidence that small, terrestrial planets are omnipresent in the Galaxy, we support previous claims that the definition of Galactic Habitable Zone should be rediscussed in view of the ubiquitous capacity of the interstellar medium to form organic molecules.
description: 11 pages, 5 figures, 3 appendices, accepted for publication in A&A
An Onsager-Machlup approach to the most probable transition pathway for a genetic regulatory network
Creators: name: Hu, Jianyu
name: Chen, Xiaoli
name: Duan, Jinqiao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Molecular Networks (q-bio.MN)
subject: Dynamical Systems (math.DS)
subject: FOS: Biological sciences
subject: FOS: Mathematics

description: We investigate a quantitative network of gene expression dynamics describing the competence development in Bacillus subtilis. First, we introduce an Onsager-Machlup approach to quantify the most probable transition pathway for both excitable and bistable dynamics. Then, we apply a machine learning method to calculate the most probable transition pathway via the Euler-Lagrangian equation. Finally, we analyze how the noise intensity affects the transition phenomena.
A Radial Velocity Study of the Planetary System of Pi Mensae: Improved Planet Parameters for PI Mensae c and a Third Planet on a 125-d Orbit
Creators: name: Hatzes, Artie P.
name: Gandolfi, Davide
name: Korth, Judith
name: Rodler, Florian
name: Sabotta, Silvia
name: Esposito, Massimiliano
name: Barragan, Oscar
name: Livingston, Vincent Van Eylen John H.
name: Serrano, Luisa Maria
name: Luque, Rafael
name: Smith, Alexis M. S.
name: Redfield, Seth
name: Persson, Carina M.
name: Paetzold, Martin
name: Palle, Enric
name: Nowak, Grzegorz
name: Osborne, Hannah L. M.
name: Narita, Norio
name: Mathur, Savita
name: Lam, Kristine W. F.
name: Kabath, Petr
name: Johnson, Marshall C.
name: Guenther, Eike W.
name: Grziwa, Sascha
name: Goffo, Elisa
name: Fridlund, Malcolm
name: Endl, Michael
name: Deeg, Hans J.
name: Csizmadia, Szilard
name: Cochran, William D.
name: Cuesta, Lucia Gonzalez
name: Chaturvedi, Priyanka
name: Carleo, Ilaria
name: Cabrera, Juan
name: Beck, Paul G.
name: Albrecht, Simon
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Pi Men hosts a transiting planet detected by the TESS space mission and an outer planet in a 5.7-yr orbit discovered by RV surveys. We studied this system using new radial velocity (RV) measurements taken with the HARPS spectrograph on ESO's 3.6-m telescope as well as archival data. We constrain the stellar RV semi-amplitude due to the transiting planet, Pi Men c, as K_c = 1.21 +/- 0.12 m/s resulting in a planet mass of M_c = 3.63 +/- 0.38 M_Earth. A planet radius of R_c= 2.145 +/- 0.015 R_Earth yields a bulk density of rho = 2.03 +/- 0.22 g/cm^{-3}. The precisely determined density of this planet and the brightness of the host star make Pi Men c an excellent laboratory for internal structure and atmospheric characterization studies. Our HARPS RV measurements also reveal compelling evidence for a third body, PI Men d, with a minimum mass M sin i = 13.38 +/- 1.35 M_Earth orbiting with a period of P_d = 125 d on an eccentric orbit (e = 0.22). A simple dynamical analysis indicates that the orbit of Pi Men d is stable on timescales of at least 20 Myrs. Given the mutual inclination between the outer gaseous giant and the inner rocky planet and the presence of a third body at 125 d, Pi Men is an important planetary system for dynamical and formation studies.
description: Accepted for publication in the Astronomical Journal. 40 pages, 16 figures
Random Models for Exploring Planet Compositions I: Uranus as an Example
Creators: name: Podolak, Joshua
name: Malamud, Uri
name: Podolak, Morris
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Modeling the interior of a planet is difficult because the small number of measured parameters is insufficient to constrain the many variables involved in describing the interior structure and composition. One solution is to invoke additional constraints based on arguments about how the planet formed. However, a planet's actual structure and composition may hold clues to its formation which would be lost if this structure were not allowed by the initial assumptions. It is therefore interesting to explore the space of allowable compositions and structures in order to better understand which cosmogonic constraints are absolutely necessary. To this end, we describe a code for generating random, monotonic, density distributions, rho(r), that fit a given mass, radius, and moment of inertia. Integrating the equation of hydrostatic equilibrium gives the pressure, P(r), at each point in the body. We then provide three algorithms for generating a monotonic temperature distribution, T(r), and an associated composition that is consistent with the rho-P relation, and realistic equations of state. We apply this code to Uranus as a proof of concept, and show that the ratio of rock to water cannot be much larger than 2.
description: 32 pages, 15 figures
Referential currency (r)
Creators: name: J Perezgonzalez
Publisher: name: figshare
Year: 2014
Subjects: Economics

description: This document describes a technological application for the field of economics. It aims to fix part of the economical wandering between the 'real' and 'nominal' value of money in order to increase standardization in reporting, as well as to allow for more meaningful comparisons in time and easier understanding by readers. The proposal made here is for a fix at sovereign currency levels rather than at international levels. That is, it works at the level of, for example, the US dollar, Australian dollar, British pound or Euro, but does not propose an international currency.
Constraints on r-modes and mountains on millisecond neutron stars in binary systems
Creators: name: Covas, P. B.
name: Papa, M. A.
name: Prix, R.
name: Owen, B. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Continuous gravitational waves are nearly monochromatic signals emitted by asymmetries in rotating neutron stars. These signals have not yet been detected. Deep all-sky searches for continuous gravitational waves from isolated neutron stars require significant computational expense. Deep searches for neutron stars in binary systems are even more expensive, but potentially these targets are more promising emitters, especially in the hundreds-Hz region, where ground-based gravitational wave detectors are most sensitive. We present here an all-sky search for continuous signals with frequency between 300 and 500 Hz, from neutron stars in binary systems with orbital period between 15 and 60 days, and projected semi-major axis between 10 and 40 light-seconds. This is the only binary search on Advanced-LIGO data that probes this frequency range. Compared to previous results, our search is over an order of magnitude more sensitive. We do not detect any signals, but our results exclude plausible and unexplored neutron star configurations, for example, neutron stars with relative deformations greater than 3e-6 within 1 kpc from Earth and r-mode emission at the level of alpha ~ few 1e-4 within the same distance.
description: Accepted for publication in The Astrophysical Journal Letters
Chemical composition, antimicrobial and insecticidal activities of the essential oils of Conyza linifolia and Chenopodium ambrosioides
Creators: name: Fathalla M. Harraz
name: Hammoda, Hala M.
name: Ghazouly, Maged G. El
name: Farag, Mohamed A.
name: El-Aswad, Ahmed F.
name: Bassam, Samar M.
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Biological Sciences
subject: Sociology
subject: FOS: Sociology
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Microbiology
subject: Biochemistry

description: Two essential oil-containing plants growing wildly in Egypt: Conyza linifolia (Willd.) Täckh. (Asteraceae) and Chenopodium ambrosioides L. (Chenopodiaceae) were subjected to essential oil analysis and biological investigation. The essential oils from both plants were prepared by hydrodistillation, and GC/MS was employed for volatiles profiling. This study is the first to perform GC/MS analysis of C. linifolia essential oil growing in Egypt. C. linifolia essential oil contained mainly sesquiterpenes, while that of C. ambrosioides was rich in monoterpenes. Ascaridole, previously identified as the major component of the latter, was found at much lower levels. In addition, the oils were investigated for their antimicrobial activity against two Gram positive and two Gram negative bacteria, and one fungus. The insecticidal activities of both oils, including mosquitocidal and pesticidal potentials, were also evaluated. The results of biological activities encourage further investigation of the two oils as antimicrobial and insecticidal agents of natural origin.
A Possible 3-Year Quasi-Periodic Oscillation in γ-Ray Emission from the FSRQ S5 1044+71
Creators: name: Wang, G. G.
name: Cai, J. T.
name: Fan, J. H.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Variability is a typical observation feature of Fermi blazars, sometimes it shows quasi-periodic oscillation (QPO). In this work, we obtained 5-day binned light curves (with a time coverage of $\sim$ 12.9 yr) for S5 1044+71 based on Fermi LAT data, adopted five different methods: Date-compensated Discrete Fourier Transform (DCDFT), Jurkevich (JV), Lomb-Scargle Periodogram (LSP), a Fortran 90 program (REDFIT) and the Weighted Wavelet Z-transform (WWZ) to the $γ$-ray light curve, and found a possible QPO of 3.06 $\pm$ 0.43 yr at the significance level of $\sim3.6σ$. A binary black hole model including accretion model and dual-jets model is used to explain this quasi-periodic variability. We also estimated the Doppler factors and the apparent velocity for the two jet components. We speculate that this $γ$-ray quasi-periodic modulation suggest the presence of a binary supermassive black hole in S5 1044+71.
description: 11 pages, 10 figures, accepted by APJ
Antioxidant activities and phenolics profiling of different parts of Carica papaya by LCMS-MS
Creators: name: V. Zunjar
name: D. Mammen
name: B.M. Trivedi
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Plant Biology
subject: FOS: Biological sciences
subject: Science Policy
subject: Biological Sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Ecology
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Molecular Biology
subject: Cell Biology
subject: Microbiology
subject: Biochemistry

description: This article deals with the comparison of the antioxidant activity of aqueous extracts of various parts of Carica papaya L. The evaluation of total phenolic content and total flavonoid content revealed high antioxidant potential of the seeds and fruits. The free radical-scavenging potential of the aqueous extracts indicated the seeds to have better DPPH-scavenging activity than fruits. The results were augmented by the FRAP activity as well. The phenolics present in the extracts were separated and identified as 5-hydroxy feruloyl quinic acid, acetyl p-coumaryl quinic acid, quercetin-3-O-rhamnoside, syringic acid hexoside, 5-hydroxy caffeic quinic acid, peonidin-3-O-glucoside, sinapic acid-O-hexoside, cyaniding-3-O-glucose and methyl feruloyl glycoside by LCMS-MS technique.
Massive black hole formation in dense stellar environments: Enhanced X-ray detection rates in high velocity dispersion nuclear star clusters
Creators: name: Baldassare, Vivienne F.
name: Stone, Nicholas C.
name: Foord, Adi
name: Gallo, Elena
name: Ostriker, Jeremiah P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We analyze Chandra X-ray Observatory imaging of 108 galaxies hosting nuclear star clusters (NSCs) to search for signatures of massive black holes (BHs). NSCs are extremely dense stellar environments with conditions that can theoretically facilitate massive BH formation. Recent work by Stone et al. (2017) finds that sufficiently dense NSCs should be unstable to the runaway growth of a stellar mass BH into a massive BH via tidal captures. Furthermore, there is a velocity dispersion threshold ($40\;\rm{km\;s^{-1}}$) above which NSCs should inevitably form a massive BH. To provide an observational test of these theories, we measure X-ray emission from NSCs and compare to the measured velocity dispersion and tidal capture runaway timescale. We find that NSCs above the $40\;\rm{km\;s^{-1}}$ threshold are X-ray detected at roughly twice the rate of those below (after accounting for contamination from X-ray binaries). These results are consistent with a scenario in which dense, high-velocity NSCs can form massive BHs, providing a formation pathway that does not rely on conditions found only at high redshift.
description: Resubmitted to AAS Journals on March 1, 2022
Metallicity, ionization parameter, and pressure variations of HII regions in the TYPHOON spiral galaxies
Creators: name: Grasha, K.
name: Chen, Q. H.
name: Battisti, A. J.
name: Acharyya, A.
name: Ridolfo, S.
name: Poehler, E.
name: Mably, S.
name: Verma, A. A.
name: Hayward, K. L.
name: Kharbanda, A.
name: Poetrodjojo, H.
name: Seibert, M.
name: Rich, J. A.
name: Madore, B. F.
name: Kewley, L. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a spatially-resolved HII region study of the gas-phase metallicity, ionization parameter, and ISM pressure maps of 6 local star-forming and face-on spiral galaxies from the TYPHOON program. Self-consistent metallicity, ionization parameter, and pressure maps are calculated simultaneously through an iterative process to provide useful measures of the local chemical abundance and its relation to localized ISM properties. We constrain the presence of azimuthal variations in metallicity by measuring the residual metallicity offset $Δ$(O/H) after subtracting the linear fits to the radial metallicity profiles. We however find weak evidence of azimuthal variations in most of the galaxies, with small (mean 0.03 dex) scatter. The galaxies instead reveal that HII regions with enhanced and reduced abundances are found distributed throughout the disk. While the spiral pattern plays a role in organizing the ISM, it alone does not establish the relatively uniform azimuthal variations we observe. Differences in the metal abundances are more likely driven by the strong correlations with the local physical conditions. We find a strong and positive correlation between the ionization parameter and the local abundances as measured by the relative metallicity offset $Δ$(O/H), indicating a tight relationship between local physical conditions and their localized enrichment of the ISM. Additionally, we demonstrate the impact of unresolved observations on the measured ISM properties by rebinning the datacubes to simulate low-resolution (1 kpc) observations, typical of large IFU surveys. We find that the ionization parameter and ISM pressure diagnostics are impacted by the loss of resolution such that their measured values are larger relative to the measured values on sub-HII region scales.
description: 31 pages, 14 figures. Accepted for publication in ApJ
Sassarandainol: a new neolignan and anti-inflammatory constituents from the stem of Sassafras randaiense
Creators: name: Hou, Ya-Ling
name: Hsun-Shuo Chang
name: Wang, Hui-Chun
name: Sheng-Yang Wang
name: Tze-Ying Chen
name: Chu-Hung Lin
name: Ih-Sheng Chen
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Science Policy
subject: Biological Sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Ecology
subject: FOS: Biological sciences
subject: Chemistry
subject: Earth and Environmental Sciences
subject: Cell Biology
subject: Physics
subject: Biochemistry

description: A new neolignan, (R)-( − )-sassarandainol (1), together with 10 known compounds (2–11), was isolated from the stem of Sassafras randaiense. The structures were determined by spectroscopic techniques. Among these isolates, γ-tocopherol (5), subamolide B (7) and β-sitosterone (9) exhibited moderate iNOS inhibitory activity on nitrite production induced (%) value of 30.51, 28.68 and 16.96, respectively.
Null Cosmic Strings: Scattering by Black Holes, Optics and Spacetime Content
Creators: name: Davydov, E. A.
name: Fursaev, D. V.
name: Tainov, V. A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Equations of motion of null cosmic strings near black holes, or other massive sources, are solved exactly in the weak field approximation. The stress-energy tensor of a null string in a curved spacetime is introduced and used to show how scattering by black holes transforms linear and angular momenta of the string. The corresponding recoil effect of a black hole and change of its angular momentum caused by a null cosmic string are calculated. For a null string, its energy $μ$ per unit length evolves along the null direction of the string trajectory. The evolution of $μ$ is connected with a string optical scalar $Z$. Optical properties of null strings are that their energy is concentrated on caustics, where $Z$ has poles. String parameters $μ$ and $Z$ capture important features of the spacetime where strings move. Explicit dependence of $μ$ and $Z$ on the strain and Bondi news tensors of gravitational wave background, mass and angular momentum aspects are established, near the future null infinity, up to the 4-th order in expansion in an inverse null parameter in asymptotically flat spacetimes.
description: 22 pages, 3 figures, 2d version which corresponds to the published manuscript
Adiabatic accretion onto black holes in Einstein-Maxwell-scalar theory
Creators: name: Feng, Haiyuan
name: Li, Miao
name: Liang, Gui-Rong
name: Yang, Rong-Jia
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the adiabatic accretion process of ordinary baryonic gas onto spherically symmetric black holes in Einstein-Maxwell-scalar theory, with two parameters $α$ and $β$ in the coupling term. Especially, we demonstrate the range of the transonic points in terms of the charge-to-mass ratio squared and the dimensionless coordinate radius, in two important classes of black holes as examples. Further, we find that the two coupling parameters give modifications to the mass accretion rate at different orders of the sound speed at infinity. We also present their different effects on the temperature ratios of the accreted gas.
description: 17 pages, 4 figures
A new and critically endangered species and genus of Onychophora (Peripatidae) from the Brazilian savannah – a vulnerable biodiversity hotspot
Creators: name: Oliveira, Ivo De Sena
name: Lacorte, Gustavo A.
name: Weck-Heimann, Andreas
name: Cordeiro, Lívia M.
name: Wieloch, Alfredo H.
name: Mayer, Georg
Publisher: name: Taylor & Francis
Year: 2015
Subjects: subject: Plant Biology
subject: FOS: Biological sciences
subject: Biological Sciences
subject: Ecology
subject: Earth and Environmental Sciences
subject: Evolutionary Biology
subject: Molecular Biology
subject: Genetics

description: In recent years, a high number of endemic species might have gone extinct silently in the Brazilian savannah (=Cerrado), a biodiversity hotspot, as researchers are not able to describe them as fast as their natural habitats are being destroyed. This especially holds true for onychophorans, or velvet worms, which include many point endemic species and, in this biome, only occur in small gallery forests susceptible to disturbances. In the present work, we use a combined morphological and molecular approach to describe a relict and critically endangered onychophoran species from the Cerrado. Our morphological analyses using light and scanning electron microscopy revealed novel characters and character states for Peripatidae, such as six interpedal structures per segment, modified scales on the genital and posterior body region of females and a third class of dermal papillae, herein named peripheral accessory papillae. Since Cerradopatus sucuriuensis gen. et sp. nov. showed a unique set of morphological characters and could not be assigned to any described genus of Peripatidae, a new genus is raised for this species herein. In addition to morphological data, the new taxon is supported by karyotypic, slime protein profiling and molecular data, including sequences of the mitochondrial genes COI and 12S rRNA. Unfortunately, Cerradopatus sucuriuensis gen. et sp. nov. is prone to an extremely high risk of extinction in the wild, as it only occurs in specific humid patches within three small, unprotected fragments of forest that are being progressively affected by human activities. According to the IUCN Red List categories and criteria, this species is classified as Critically Endangered and requires urgent conservation efforts.http://zoobank.org/urn:lsid:zoobank.org:pub:10D0762E-7842-428B-8ABB-9096BED10F65
EXORCISM: a spectroscopic survey of young eruptive variables (EXor and candidates)
Creators: name: Giannini, T.
name: Giunta, A.
name: Gangi, M.
name: Carini, R.
name: Lorenzetti, D.
name: Antoniucci, S.
name: Garatti, A. Caratti o
name: Cassarà, L.
name: Nisini, B.
name: Rossi, A.
name: Testa, V.
name: Vitali, F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra ($\Re$ $\sim$ 1500-2000) were collected between 2014-2019 with the Large Binocular Telescope (LBT). From the spectral analysis we have derived the accretion luminosity and mass accretion rate, the visual extinction, the temperature and density of the permitted line formation region, and the signature of the outflowing matter. Two sources (ASASSN-13db and iPTF15afq) have been observed in outburst and quiescence, three during a high-level of brightness (XZ Tau, PV Cep, and NY Ori), and the others in quiescence. These latter have accretion luminosity and mass accretion rates in line with the values measured in classical T Tauri stars of similar mass. All sources observed more than once present accretion variability. The most extreme case is ASASSN-13db, for which the mass accretion rate decreases by two orders of magnitude from the outburst peak in 2015 to quiescence in 2017. Also, in NY Ori the accretion luminosity decreases by a factor 25 in one year. In 80% of the sample we detect the [OI]630 nm line, a tracer of mass loss. From the variability of the H$α$/[OI]630, ratio, we conclude that mass accretion variations are larger than mass loss variations. From the analysis of the HI recombination lines a correlation is suggested between the density of the line formation region and the level of accretion activity of the source.
description: To appear in ApJ
X-ray Emission and Radio Emission from the Jets and Lobes of the Spiderweb Radio Galaxy
Creators: name: Carilli, Christopher L.
name: Anderson, Craig S.
name: Tozzi, Paolo
name: Pannella, Maurilio
name: Clarke, Tracy
name: Pentericci, L.
name: Liu, Ang
name: Mroczkowski, Tony
name: Miley, G. K.
name: Rottgering, H. J.
name: Borgani, S.
name: Norman, Colin
name: Saro, A.
name: Nonino, M.
name: Di Mascolo, L.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Deep Chandra and VLA imaging reveals a clear correlation between X-ray and radio emission on scales $\sim 100$~kpc in the Spiderweb radio galaxy at z=2.16. The X-ray emission associated with the extended radio source is likely dominated by inverse Compton up-scattering of cosmic microwave background photons by the radio emitting relativistic electrons. For regions dominated by high surface brightness emission, such as hot spots and jet knots, the implied magnetic fields are $\sim 50~μ$G to $70~μ$G. The non-thermal pressure is these brighter regions is then $\sim 9\times 10^{-10}$ dyne cm$^{-2}$, or three times larger than the non-thermal pressure derived assuming minimum energy conditions, and an order of magnitude larger than the thermal pressure in the ambient cluster medium. Assuming ram pressure confinement implies an average advance speed for the radio source of $\sim 2400$ km s$^{-1}$, and a source age of $\sim 3\times 10^7$ years. Considering the lower surface brightness, diffuse radio emitting regions, we identify an evacuated cavity in the Ly$α$ emission coincident with the tail of the eastern radio lobe. Making reasonable assumptions for the radio spectrum, we find that the relativistic electrons and fields in the lobe are plausibly in pressure equilibrium with the thermal gas, and close to a minimum energy configuration. The radio morphology suggests that the Spiderweb is a high-$z$ example of the rare class of hybrid morphology radio sources (or HyMoRS), which we attribute to interaction with the asymmetric gaseous environment indicated by the Ly$α$ emission.
description: 8 figures, 25 pages, to appear in the ApJ
An Infrared view of the obscured AGN environment in NGC 4945
Creators: name: Gaspar, Gaia
name: Díaz, Rubén J.
name: Mast, Damián
name: Agüero, María Paz
name: Schirmer, Mischa
name: Günthardt, Guillermo
name: Schmidt, Eduardo O.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: NGC 4945 harbors one of the nearest active galactic nuclei (AGN), which allows reaching high spatial resolution with the current observational facilities. The Seyfert 2 nucleus is deeply obscured by an edge-on disk with $A_V\sim14$, requiring infrared observations to study circumnuclear structures and the interstellar medium. In this work, we present an imaging and longslit spectroscopic study of the nuclear region with a spatial resolution of 6.5 pc, based on Flamingos-2 (F2) and T-ReCS data taken at the Gemini South observatory. We report sub-arcsecond photometric measurements of the nucleus in $J$, $H$ and $K_{\rm s}$ filters, and at larger apertures. We do not detect nuclear variability. The nuclear spectra confirm that even in $K$-band the AGN emission-line features are completely obscured by dust. We detect a circumnuclear disk in $K$-band as well as in the mid-infrared (MIR) $N$- and $Q_{\rm a}$-bands, with a radial scale length of $\sim$120 pc. The disk shows knots mostly in a ring-like arrangement that has been previously detected with HST Pa $α$ observations, indicating that these are deeply embedded, massive young star clusters. We present here the spectrum of one of the brightest and unresolved object (R$<5$pc), which we identify as a super star cluster candidate with M$_{K_{\rm s}} -16.6\pm0.4$. For the circumnuclear region, a detailed rotation curve allows to measure a nuclear mass of $M=(4.4 \pm 3)\times 10^{6} M_\odot$ within a radius of $\sim6.5$ pc. We also report the detection of hot dust ($\sim 1000$ K) out to a nuclear distance of 80 pc measured along the semi-major axis.
description: 14 pages