Miracle-dz/UniFAR-FTUs huggingface dataset:
Is the accretion flow in ngc 4258 advection-dominated?

The mass of the central black hole in the active galaxy NGC 4258 (M106) has been measured to be $M=3.6\times10^7\Msun$ (Miyoshi et al. 1995). The Eddington luminosity corresponding to this mass is $L_E=4.5\times10^{45}$ erg s$^{-1}$. By contrast the X-ray luminosity of the nucleus of NGC 4258 between $2-10$ keV is $(4\pm 1)\times10^{40}~{\rm erg\,s^{-1}}$ while the optical/UV luminosity is less than $1.5\times10^{42} ~{\rm erg\,s^{-1}}$. The luminosity of NGC 4258 is therefore extremely sub-Eddington, $L\sim10^{-5}L_E$ in X-rays and $L\sim3\times10^{-4} L_E$ even if we take the maximum optical/UV luminosity. Assuming the usual accretion efficiency of 0.1 would imply accretion rates orders of magnitude lower than in Seyfert galaxies and quasars. We show that the properties of the AGN in NGC 4258 can be explained by an accretion flow in the form of a very hot, optically-thin plasma which advects most of the viscously generated thermal energy into the central black hole and radiates only a small fraction of the energy. In this case the accretion rate in Eddington units could be as high as $\sim 0.16\alpha$, where $\alpha$ is the standard viscosity parameter; and the size of the hot disk should be larger than $\sim 10$ times the Schwarzschild radius. We compare the predictions of this model with observations and discuss its application to other low luminosity AGN.
Exceptionally fast ejecta seen in light echoes of Eta Carinae’s Great Eruption

In our ongoing study of eta Carinae's light echoes, there is a relatively bright echo that has been fading slowly, reflecting the 1845-1858 plateau of the eruption. A separate paper discusses its detailed evolution, but here we highlight one important result: the H-alpha line shows extremely broad emission wings that reach -10,000km/s to the blue and +20,000km/s to the red. The line profile shape is inconsistent with electron scattering wings, indicating high-velocity outflowing material. These are the fastest outflow speeds ever seen in a non-terminal massive star eruption. The broad wings are absent in early phases of the eruption, but strengthen in the 1850s. These speeds are two orders of magnitude faster than the escape speed from a warm supergiant, and 5-10 times faster than winds from O-type or Wolf-Rayet stars. Instead, they are reminiscent of fast supernova ejecta or outflows from accreting compact objects, profoundly impacting our understanding of eta Car and related transients. This echo views eta Car from latitudes near the equator, so the high speed does not trace a collimated polar jet aligned with the Homunculus. Combined with fast material in the Outer Ejecta, it indicates a wide-angle explosive outflow. The fast material may constitute a small fraction of the total outflowing mass, most of which expands at 600 km/s. This is reminiscent of fast material revealed by broad absorption during the presupernova eruptions of SN2009ip.
Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 6: Variability of NGC 3783 from ground-based data

The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which complement the data set formed by the International Ultraviolet Explorer (IUE) spectra, discussed elsewhere. Spectroscopic and photometric data from several observatories were combined in order to obtain well-sampled light curves of the continuum and of H(beta). During the campaign the source underwent significant variability. The light curves of the optical continuum and of H(beta) display strong similarities to those obtained with the IUE. The near-IR flux did not vary significantly except for a slight increase at the end of the campaign. The cross-correlation analysis shows that the variations of the optical continuum have a lag of 1 day or less with respect to those of the UV continuum, with an uncertainty of is less than or equal to 4 days. The integrated flux of H(beta) varies with a delay of about 8 days. These results confirm that (1) the continuum variations occur simultaneously or with a very small lag across the entire UV-optical range, as in the Seyfert galaxy NGC 5548; and (2) the emission lines of NGC 3783 respond to ionizing continuum variations with less delay than those of NGC 5548. As observed in NGC 5548, the lag of H(beta) with respect to the continuum is greater than those of the high-ionization lines.
IMPACT OF ONLINE TEACHING AND LEARNING EXPERIENCES OF UNDERGRADUATE DENTAL STUDENTS OF BAPUJI DENTAL COLLEGE DURING COVID-19 PANDEMIC – A CROSS SECTIONAL SURVEY

Background: Dental schools were compelled to temporarily close clinics due to the coronavirus disease (COVID-19) and switch from traditional classroom instruction to distance learning. The aim of our survey was to determine the impact of online education on dental students and to find out the preparedness of final year dental students for independent practice after their graduation.Methods: A cross sectional survey was conducted among 300 BDS students studying in Bapuji dental College. The questionnaire was distributed online using email. The questionnaire was divided into two parts: the first portion included online learning experience, while the second section concentrated on readiness for independent dental practise.Results: The survey received an 81% response rate. Nearly 95.6% of fourth-year BDS students reported that their clinical training had a negative impact. Due to lockdown, the majority (82%) of our students missed their clinical classes. BDS students in the first (81%) second (85%) third (54%) and fourth (82%) years favoured the traditional lecture method (p 0.001). Online lessons are not a suitable way to improve communication skills, according to our students (70.5%). Students in the final year reported decreased confidence in their ability to set up independent practise following graduation.Conclusion: Online learning is not a substitute for in-person clinical classes, according to our students. The amount of readiness for independent practise was not positive.
Antitumor Activities of Interleukin-12 in Melanoma

Simple Summary Immunotherapy has been evolving rapidly in recent years. As a key component of the immune system, cytokines play essential roles not only in immune regulation but also in anti-tumor immunity. In the present review, we summarized the basic biological activities of IL-12 and its application in clinical trials for the therapy of melanoma. We also discussed the combined therapy of IL-12 with immune checkpoint inhibitors, cytokines and other therapeutic drugs in preclinical and clinical studies. The immune-related side effects of IL-12 and promising technological approaches that improve the efficacy and safety of IL-12 or IL-12 encoding vectors in the treatment of melanoma are also discussed. Abstract Melanoma is the most common and serious malignant tumor among skin cancers. Although more and more studies have revolutionized the systematic treatment of advanced melanoma in recent years, access to innovative drugs for melanoma is still greatly restricted in many countries. IL-12 produced mainly by antigen-presenting cells regulates the immune response and affects the differentiation of T cells in the process of antigen presentation. However, the dose-limited toxicity of IL-12 limits its clinical application. The present review summarizes the basic biological functions and toxicity of IL-12 in the treatment of melanoma and discusses the clinical application of IL-12, especially the combination of IL-12 with immune checkpoint inhibitors, cytokines and other therapeutic drugs. We also summarize several promising technological approaches such as carriers that have been developed to improve the pharmacokinetics, efficacy and safety of IL-12 or IL-12 encoding plasmid application.
Motion of a Solar Mass Compact Object Around a Massive Rotating Black Hole

This preprint is based on two articles accepted by MNRAS and ApJ. Our aim is to study the evolution of the orbit of a star under the influence of interactions with an accretion disc in an AGN. The model considered consists of a low-mass compact object orbiting a supermassive black hole and colliding periodically with the accretion disc. Gravitational field of the nucleus is described by the Kerr metric. The star is assumed to move along a geodesic arc between successive interactions with an equatorial accretion disc. We study the gravitomagnetic (Lense-Thirring) precession of the trajectory. We do not assume any particular value for the eccentricity or inclination of the orbit or the angular momentum of the black hole. We also discuss the periodicity related to the relativistic shift of the pericenter. The model of star-disc interactions has been suggested to explain the X-ray variability observed in the Seyfert galaxy NGC~6814. We briefly discuss on this subject.
Solar photocatalytic degradation of amoxicillin using Ni:TiO2 nanocatalyst stabilized on ceramic plates

The main aim of this study was to investigate the photocatalytic degradation of amoxicillin in an aqueous medium using Ni:TiO 2 nanoparticles stabilized on ceramic surfaces under natural sun- light irradiation. Ni:TiO 2 nanoparticles were synthesized using a hydrothermal method and char- acterized using X-ray diffraction, scanning electron microscope, and Fourier-transform infrared spectroscopy techniques. The nanoparticles were then stabilized on the ceramic surface in a fur- nace. The effects of operational parameters such as the doping percentage (doping ratio), initial pH, contact time, and initial amoxicillin concentration on the photocatalytic degradation efficiency (PDE) of amoxicillin were examined in the presence of natural sunlight irradiation. The reusability of the stabilized nanoparticles was also studied. Based on these results, the amoxicillin PDE under natural sunlight irradiation was enhanced by increasing the doping percentage of synthesized nanoparticles and the contact time, while increasing the initial pH and the initial concen- tration of amoxicillin led to a reduction in the amoxicillin PDE. The results revealed that 78.4% PDE was obtained for amoxicillin using Ni:TiO 2 nanoparticles under optimal conditions for the photocatalytic process. This efficiency rate was higher than the PDE of TiO 2 nanoparticles and the degradation efficiency of solar irradiation by 22.97% and 66.1%, respectively. Moreover, the amoxicillin PDE was reduced after each reuse of the Ni:TiO 2 nanoparticles stabilized on the ceramic.
Convection-aided Explosions in One-dimensional Core-collapse Supernova Simulations. I. Technique and Validation

Most one-dimensional core-collapse simulations fail to explode, yet multidimensional simulations often explode. A dominant multidimensional effect aiding explosion is neutrino-driven convection. We incorporate a convection model in approximate one-dimensional core-collapse supernova (CCSN) simulations. This is the 1D+ method. This convection model lowers the neutrino luminosity required for explosion by %, similar to the reduction observed in multidimensional simulations. The model is based upon the global turbulence model of Mabanta & Murphy and models the mean-field turbulent flow of neutrino-driven convection. In this preliminary investigation, we use simple neutrino heating and cooling algorithms to compare the critical condition in the 1D+ simulations with the critical condition observed in two-dimensional simulations. Qualitatively, the critical conditions in the 1D+ and the two-dimensional simulations are similar. The assumptions in the convection model affect the radial profiles of density, entropy, and temperature, and comparisons with the profiles of three-dimensional simulations will help to calibrate these assumptions. These 1D+ simulations are consistent with the profiles and explosion conditions of equivalent two-dimensional CCSN simulations but are ∼102 times faster, and the 1D+ prescription has the potential to be ∼105 faster than three-dimensional CCSN simulations. With further calibration, the 1D+ technique could be ideally suited to test the explodability of thousands of progenitor models.
Hyper-sparsity of the density matrix in a wavelet representation

O(N) methods are based on the decay properties of the density matrix in real space, an effect sometimes refered to as near-sightedness. We show, that in addition to this near-sightedness in real space there is also a near-sightedness in Fourier space. Using a basis set with good localization properties in both real and Fourier space such as wavelets, one can exploit both localization properties to obtain a density matrix which exhibits additional sparseness properties compared to the scenario where one has a basis set with real space localization only. We will call this additional sparsity hyper-sparsity. Taking advantage of this hyper-sparsity, it is possible to represent very large quantum mechanical systems in a highly compact way. This can be done both for insulating and metallic systems and for arbitrarily accurate basis sets. We expect that hyper-sparsity will pave the way for O(N) calculations of large systems requiring many basis functions per atom, such as Density Functional calculations.
An independent calibration of stellar ages: Hubble Space Telescope observations of white dwarfs at V = 25

The white dwarf luminosity function of a stellar cluster will have a sharp truncation at a luminosity which is determined by the time since formation of the first white dwarfs in that cluster. Calculation of the dependence of this limiting luminosity on age requires relatively well-understood physics and is independent of stellar evolutionary models. Thus, measurement of the termination of the white dwarf luminosity function provides an independent method to determine the age of a cluster, and thereby to calibrate stellar evolutionary ages. We have obtained HST WFPC2 data in two open clusters, identified the white dwarf sequence, and proved the feasibility of this approach, by detecting white dwarfs to V=25. Much deeper data are feasible. From our present limited data, we show that degenerate cooling ages are not consistent with some published isochrone ages for clusters with ages of order 1Gyr.
The Milky Way, Local Galaxies, and the Infrared Tully-Fisher Relation

Using the near-infrared fluxes of local galaxies derived from Cosmic Background Explorer (COBE)/ Diffuse Infrared Background Experiment (DIRBE)COBE data sets were devloped by the NASA Goddard Space Flight Center under the guidance of the COBE Science Working Group and were provided by the National Space Science Data Center (NSSDC). J- (1.25 μm) K- (2.2 μm), and L-band (3.5 μm) maps and published Cepheid distances, we construct Tully-Fisher (TF) diagrams for nearby galaxies. The measured dispersions in these luminosity-line width diagrams are remarkably small: σJ = 0.09 mag, σK = 0.13 mag, and σL = 0.20 mag. These dispersions include contributions from the intrinsic TF relation scatter and the errors in estimated galaxy distances, fluxes, inclination angles, extinction corrections, and circular speeds. For the J and K bands, Monte Carlo simulations give a 95% confidence interval upper limit on the true scatter in the TF diagram of σJ ≤ 0.35 and σK ≤ 0.45. We determine the Milky Way's luminosity and place it in the TF diagram by fitting a bar plus exponential disk model of the Milky Way to the all-sky DIRBE maps. For “standard” values of its size and circular speed (Sun-Galactic center distance R0 = 8.5 kpc and Θ0 = 220 km s–1), the Milky Way lies within 1.5 σ of the TF relations. We can use the TF relation and the Cepheid distances to nearby bright galaxies to constrain R0 and Θ: 1.63 log (Θ0/220 km s–1) - log (R0/8.5 kpc) = 0.08 ± 0.03. Alternatively, we can fix the parameters of the Galaxy to their standard values, ignore the Cepheid zero point, and use the TF relation to determine the Hubble constant directly: H0 = 72 ± 12 km s–1 Mpc–1. We have also tested the TF relation at longer wavelengths, where the emission is dominated by dust. We find no evidence for a TF relation at wavelengths beyond 10 μm. The tight correlation seen in the L band suggests that stellar emission dominates over the 3.3 μm polycyclic aromatic hydrocarbon emission.
Diverse Long-term Variability of Five Candidate High-mass X-Ray Binaries from Swift Burst Alert Telescope Observations

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ∼30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.
Numerical Solution of Singularly Perturbed Problems via both Galerkin and Subdomain Galerkin methods

In this paper, numerical solutions of singularly perturbed boundary value problems are given by using variants of finite element method. Both Galerkin and subdomain Galerkin method based on quadratic B-spline functions are applied over the geometrically graded. Results of some text problems are compated with analytical solutions of the singularly perturbed problem
Meteorology in society and practical developments

The intellectual and cultural dimensions of the science of meteorology and its applications are now widely appreciated. The revolutions in worldwide media and communication technology enable the public and decision‐makers to be much better informed about the present and future state of weather, environment and climate, and their practical implications. Non‐specialists can now understand and engage in debating some of the main scientific questions facing meteorologists. The institutional and political issues associated with these developments are discussed, particularly the organizational arrangements for the measurement, forecasting, exchange of data and public communication. The effectiveness and functioning of national meteorological services (NMS) and international organizations involved in meteorology depend on their financing and governance, and also their policies for the exchange of data. These factors also affect how they collaborate with other public and private organizations, especially those in related sciences and technologies. Advances in science and computing are progressively improving the accuracy and reliability of weather forecasting and climate predictions, including estimates of their intrinsic limitations. The Internet, which is providing a greater variety of meteorological data to members of the public, also enables them to contribute, not only as voluntary observers and in assisting with warnings of extreme events, but even in participating in computer experiments about climate predictions. The public as well as weather professionals now also provide valuable feedback to forecasting organizations. The role of meteorology becomes even more central to societies as they prepare for the dangers associated with significant changes in climate and environment caused by human activities. Policies to reduce these dangers have to be based on predicting future climate trends, taking into account how societies will respond to these dangers over periods of decades and centuries. There are doubts as to whether emissions of greenhouse gases will be reduced soon enough to avoid critical changes to the environment; failing that, what local and/or global measures might be taken to moderate climate change artificially? Suggestions are made about a better understanding between meteorology, government and society to deal with such issues. Copyright © 2012 Royal Meteorological Society
Fully Coupled Simulation of Cosmic Reionization. III. Stochastic Early Reionization by the Smallest Galaxies

Previously we identified a new class of early galaxy that we estimate contributes up to 30% of the ionizing photons responsible for reionization. These are low-mass halos in the range = 106.5–108 that have been chemically enriched by supernova ejecta from prior Population III star formation. Despite their low star formation rates, these metal cooling halos (MCs) are significant sources of ionizing radiation, especially at the onset of reionization, owing to their high number density and ionizing escape fractions. Here we present a fully coupled radiation hydrodynamic simulation of reionization that includes these MCs, as well the more massive hydrogen atomic line cooling halos. Our method is novel: we perform halo finding in line with the radiation hydrodynamical simulation and assign escaping ionizing fluxes to halos using a probability distribution function (pdf) measured from the galaxy-resolving Renaissance Simulations. The pdf captures the mass dependence of the ionizing escape fraction, as well as the probability that a halo is actively forming stars. With MCs, reionization starts earlier than if only halos of 108 and above are included; however, the redshift when reionization completes is only marginally affected, as this is driven by more massive galaxies. Because star formation is intermittent in MCs, the earliest phase of reionization exhibits a stochastic nature, with small H ii regions forming and recombining. Only later, once halos of mass ∼109 and above begin to dominate the ionizing emissivity, does reionization proceed smoothly in the usual manner deduced from previous studies. This occurs at z ≈ 10 in our simulation.
THE INFLUENCE OF AN INDIVIDUAL OPINION IN THE SZNAJD MODEL

The method of Damage Spreading was used to simulate the influence that a single persons' change of opionion has on the consensus opinion built up in a population if one assumes opinions to form according to the Sznajd Model. The results confirm the intuitive assumption that there is hardly any chance for one person to change the consensus, that the effect of this change dies out after a certain time and its range decreases with time. The consensus times were compared and it turned out that the consensus can be delayed or accelerated by this slight modification and that the amount of the difference in the consensus times obeys a certain power law as well as the lifetime of the effect. Moreover, two scaling laws concerning temporal and spatial aspects could be observed up to a certain size of population.