Miracle-dz/UniFAR-FTUs huggingface dataset:
Topological thermal Hall effect for topological excitations in spin liquid: Emergent Lorentz force on the spinons

We study the origin of Lorentz force on the spinons in a U(1) spin liquid. We are partly inspired by the previous observation of gauge field correlation in the pairwise spin correlation using the neutron scattering measurement by P.A. Lee an N. Nagaosa [PhysRevB 87,064423(2013)] when the Dzyaloshinskii-Moriya interaction intertwines with the lattice geometry. We extend this observation to the Lorentz force that exerts on the (neutral) spinons. The external magnetic field, that polarizes the spins, effectively generates an internal U(1) gauge flux for the spinons and twists the spinon motion through the Dzyaloshinskii-Moriya interaction. Such a mechanism for the emergent Lorentz force differs fundamentally from the induction of the internal U(1) gauge flux in the weak Mott insulating regime from the charge fluctuations. We apply this understanding to the specific case of spinon metals on the kagome lattice. Our suggestion of emergent Lorentz force generation and the resulting topological thermal Hall effect may apply broadly to other non-centrosymmetric spin liquids with Dzyaloshinskii-Moriya interaction. We discuss the relevance with the thermal Hall transport in kagome materials volborthite and kapellasite.
Statistical and polarization properties of giant pulses of the millisecond pulsar B1937+21

We have studied the statistical and polarization properties of giant pulses (GPs) emitted by the millisecond pulsar B1937+21, with high sensitivity and time resolution. The observations were made in June 2005 with the 100-m Robert C. Byrd Green Bank Telescope at S-band (2052-2116 MHz) using the Mk5A VLBI recording system, with formal time resolution of 16 ns. The total observing time was about 4.5 hours; the rate of detection of GPs was about 130 per hour at the average longitudes of the main pulse (MPGPs) and 60 per hour at the interpulse (IPGPs). While the average profile shows well-defined polarization behavior, with regular evolution of the linear polarization position angle (PA), GPs exhibit random properties, occasionally having high linear or circular polarization. Neither MPGPs nor IPGPs show a preferred PA. The cumulative probability distribution (CPD) of GP pulse energy was constructed down to the level where GPs merge with regular pulses and noise. For both MPGPs and IPGPs, the CPD follows a power law with a break, the power index changing from -2.4 at high energy to -1.6 for low energy. Pulse smearing due to scattering masks the intrinsic shape and duration of the detected GPs. The smearing time varied during the observing session within a range of a few hundred nanoseconds. The measured polarization and statistical properties of GPs impose strong constraints on physical models of GPs. Some of these properties support a model in which GPs are generated by the electric discharge caused by magnetic reconnection of field lines connecting the opposite magnetic poles of a neutron star.
New theoretical approaches to Bose polarons

The Fr\"ohlich polaron model describes a ubiquitous class of problems concerned with understanding properties of a single mobile particle interacting with a bosonic reservoir. Originally introduced in the context of electrons interacting with phonons in crystals, this model found applications in such diverse areas as strongly correlated electron systems, quantum information, and high energy physics. In the last few years this model has been applied to describe impurity atoms immersed in Bose-Einstein condensates of ultracold atoms. The tunability of microscopic parameters in ensembles of ultracold atoms and the rich experimental toolbox of atomic physics should allow to test many theoretical predictions and give us new insights into equilibrium and dynamical properties of polarons. In these lecture notes we provide an overview of common theoretical approaches that have been used to study BEC polarons, including Rayleigh-Schr\"odinger and Green's function perturbation theories, self-consistent Born approximation, mean-field approach, Feynman's variational path integral approach, Monte Carlo simulations, renormalization group calculations, and Gaussian variational ansatz. We focus on the renormalization group approach and provide details of analysis that have not been presented in earlier publications. We show that this method helps to resolve striking discrepancy in polaron energies obtained using mean-field approximation and Monte Carlo simulations. We also discuss applications of this method to the calculation of the effective mass of BEC polarons. As one experimentally relevant example of a non-equililbrium problem we consider Bloch oscillations of Bose polarons and demonstrate that one should find considerable deviations from the commonly accepted phenomenological Esaki-Tsu model. We review which parameter regimes of Bose polarons can be achieved in various atomic mixtures.
Brain Metastases in Adults: A Five-Year Observational Study From King Abdulaziz Medical City

Background As a well-documented fact, metastatic brain tumors are the most common cause of brain tumors in adults, with an incidence of 9-17%, based on various studies, although it was thought to be higher. The aim of this study was to describe recorded cases of metastatic brain tumors in the adult population of a tertiary care and oncology center in Jeddah, Saudi Arabia. Methods This study was conducted at King Abdulaziz Medical City (KAMC) at King Khalid Hospital in Jeddah, Saudi Arabia, including records from January 2016 to December 2020. The study implemented a retrospective cohort design to fulfill its aim. A data collection sheet containing demographic data such as age and gender, and information pertaining to the primary pathology, multiplicity, and survival outcome was used. Results A total number of 213 patients were enrolled in this study. Overall, 68.1% of the sample comprised of females. Approximately two-thirds (61.9%) of the patients’ imaging results revealed multiplicity, whereas the remaining third (38.1%) had solitary lesions. The estimated overall survival median after the diagnosis of brain metastasis was six months (95% CI: 5.5-6.5). Conclusion We recommend conducting a nationwide study to better understand the incidence in accordance to geographical and gender differences. We can further expand our research to include other institutes in Saudi Arabia, and include important predictors such as time from the diagnosis of primary pathology to brain metastasis, disease progression cost, and disease progression in the months prior to the patients’ death.
Spin and energy currents in integrable and nonintegrable spin-1/2 chains: A typicality approach to real-time autocorrelations

We use the concept of typicality to study the real-time dynamics of spin and energy currents in spin-1/2 models in one dimension and at nonzero temperatures. These chains are the integrable XXZ chain and a nonintegrable modification due to the presence of a staggered magnetic field oriented in z direction. In the framework of linear response theory, we numerically calculate autocorrelation functions by propagating a single pure state, drawn at random as a typical representative of the full statistical ensemble. By comparing to small-system data from exact diagonalization (ED) and existing short-time data from time-dependent density matrix renormalization group (tDMRG), we show that typicality is satisfied in finite systems over a wide range of temperature and is fulfilled in both, integrable and nonintegrable systems. For the integrable case, we calculate the long-time dynamics of the spin current and extract the spin Drude weight for large systems outside the range of ED. We particularly provide strong evidence that the high-temperature Drude weight vanishes at the isotropic point. For the nonintegrable case, we obtain the full relaxation curve of the energy current and determine the heat conductivity as a function of magnetic field, exchange anisotropy, and temperature.
Probing Radio Emission in Seyfert Galaxies on Parsec- and Kiloparsec-scales

Seyfert galaxies have traditionally been classified as radio-quiet active galactic nuclei. A proper consideration of the nuclear optical emission however proves that a majority of Seyferts are radio-loud. Kpc-scale radio lobes/bubbles are in fact revealed in sensitive observations at low radio frequencies of several Seyferts. Through the use of very long baseline interferometry, we have been able to determine the direction of the parsec-scale jets in some of these Seyfert galaxies. The misalignment between the parsec-scale jets and the kpc-scale lobes that is typically observed, is either suggestive of no connection between the two, or the presence of curved jets that power the radio lobes. In this context, we briefly discuss our new low radio frequency GMRT observations of two Seyfert galaxies with lobes.
Effect of Different Horizontal Condylar Guidance Registration Methods and Articulators on Bilateral Balanced Occlusion of Complete Denture

Purpose: To evaluate the effect of different horizontal condylar guidance registration methods and articulators on bilateral balanced occlusion of complete denture. Materials and Methods: Twelve completely edentulous patients with ages ranging from 50-60 years old were selected from the outpatient clinics of the Removable Prosthodontic Department, Faculty of Dental Medicine for Girls, Al-Azhar University. Twelve complete dentures were constructed according to the balanced occlusal concept and then duplicated for experimental work. Horizontal condylar guidance angles were measured using three different methods; the protrusive interocclusal wax record method, tracing method, and Cone Beam Computed Tomography (CBCT) scan. The angles were adjusted on two types of articulators; Arcon and non-Arcon articulators. The effect of each method and the effect of the two types of articulators on bilateral balanced occlusion were studied. Results: The result of this study showed that there was no significant difference in bilateral balanced occlusion when using different types of articulators or different horizontal condylar guidance registration methods during the construction of complete denture. Conclusion: Within the limitation of this study, it can be concluded that the Hanau system with the wax protrusive record may be the most practical way to obtain the desired relative horizontal condylar angle.
THE s-PROCESS IN ASYMPTOTIC GIANT BRANCH STARS OF LOW METALLICITY AND THE COMPOSITION OF CARBON-ENHANCED METAL-POOR STARS

We present models for the slow neutron-capture process (s-process) in asymptotic giant branch stars of metallicity [Fe/H] = −2.3 and masses 0.9–6 M☉. We encountered different regimes of neutron-capture nucleosynthesis listed here increasing in importance as the stellar mass decreases: the 22Ne(α, n)25Mg reaction activated during the thermal pulses (TPs), the 13C(α, n)16O reaction activated in radiative conditions during the interpulse periods, and the 13C(α, n)16O reaction activated during the TPs, also as a result of mild proton-ingestion episodes. The models where the 13C burns radiatively (masses ≃2 M☉) produce an overall good match to carbon-enhanced metal-poor (CEMP) stars showing s-process enhancements (CEMP-s), except they produce too much Na and F. On the other hand, none of our models can provide a match to the composition of CEMP stars also showing rapid-process enhancements (CEMP-s/r). The models fail to reproduce the observed Eu abundances, and they also fail to reproduce the correlation between the Eu and Ba abundances. They also cannot match the ratio of heavy-to-light s-process elements observed in many CEMP-s/r stars, which can be more than 10 times higher than in the solar system. To explain the composition of CEMP-s/r stars we need to invoke the existence of a different “s/r” neutron-capture process either with features in between the s- and the r-processes, or generated by superpositions of different neutron-capture processes in the same astrophysical site or in sites linked to each other—for example, in multiple stellar systems.
From the first stars to the first black holes

The growth of the first super massive black holes (SMBHs) at z > 6 is still a major challenge for theoretical models. If it starts from black hole (BH) remnants of Population III stars (light seeds with mass ~ 100 Msun) it requires super-Eddington accretion. An alternative route is to start from heavy seeds formed by the direct collapse of gas onto a ~ 10^5 Msun BH. Here we investigate the relative role of light and heavy seeds as BH progenitors of the first SMBHs. We use the cosmological, data constrained semi-analytic model GAMETE/QSOdust to simulate several independent merger histories of z > 6 quasars. Using physically motivated prescriptions to form light and heavy seeds in the progenitor galaxies, we find that the formation of a few heavy seeds (between 3 and 30 in our reference model) enables the Eddington-limited growth of SMBHs at z > 6. This conclusion depends sensitively on the interplay between chemical, radiative and mechanical feedback effects, which easily erase the conditions that allow the suppression of gas cooling in the low metallicity gas (Z Jcr). We find that heavy seeds can not form if dust cooling triggers gas fragmentation above a critical dust-to-gas mass ratio (D > Dcr). In addition, the relative importance of light and heavy seeds depends on the adopted mass range for light seeds, as this dramatically affects the history of cold gas along the merger tree, by both SN and AGN-driven winds.
Authentic Leadership and Job Satisfaction: Measuring the Mediating Role of Affective Organizationl Commitment in Healthcare Sector of Pakistan

Lack of ethics, values, morality and integrity of leadership has always been an issue for corporate world. Keeping in view the disastrous effects of lack of leadership character; this study aims to determine the impact of authentic leadership on job satisfaction of healthcare staff with the mediating effect of affective organizational commitment. This is a cross-sectional hypothesis testing research based on primary data collected from 332 respondents from five healhcare institutions based in Karachi. Confirmatory factor analysis (CFA), reliability analysis and regression analysis were performed to measure the initial validity of constrsuct and to test proposed hypotheses. The results supported the proposed hypotheses suggesting that there is a significant impact of authentic leadership on job satisfaction with complete mediation of affective organizational commitment. Implying that a committed, satisfied and engaged employee is an asset for any organizations; it will be a loss for any organization to loose such an employee. Senior management of healthcare organizations should aim to focus on training of leaders and managers so they can equip themselves with the skills and traits of authentic leadership; this will not only help organizations to retain quality human resource but will also help to enhance the positive work environment.
Dust formation in the ejecta of the type II-P supernova 2004dj

Aims. Core-collapse supernovae (CC SNe), especially type II-Plateau ones, are thought to be important contributors to cosmic dust production. SN 2004dj, one of the closest and brightest SN since 1987A, offered a good opportunity to examine dust-formation processes. To find signs of newly formed dust, we analyze all available mid-infrared (MIR) archival data from the Spitzer space telescope. Methods. We re-reduced and analyzed data from IRAC, MIPS, and IRS instruments obtained between +98 and +1381 days after explosion and generated light curves and spectra for each epoch. Observed spectral energy distributions are fitted with both analytic and numerical models, using the radiative-transfer code MOCASSIN for the latter ones. We also use imaging polarimetric data obtained at +425 days by the Hubble space telescope. Results. We present convincing evidence of dust formation in the ejecta of SN 2004dj from MIR light curves and spectra. Significant MIR excess flux is detected in all bands between 3.6 and 24 μm. In the optical, a ∼0.8% polarization is also detected at a 2-sigma level, which exceeds the interstellar polarization in that direction. Our analysis shows that the freshly-formed dust around SN 2004dj can be modeled assuming a nearly spherical shell that contains amorphous carbon grains, which cool from ∼700 K to ∼400 K between +267 and +1246 days. Persistent excess flux is found above 10 μ m, which is explained by ac old (∼115 K) dust component. If this cold dust is of circumstellar origin, it is likely to be condensed in a cool, dense shell between the forward and reverse shocks. Pre-existing . ––– – +++ –– –––– –
POST-MERGER SIGNATURES OF RED-SEQUENCE GALAXIES IN RICH ABELL CLUSTERS AT z ≲ 0.1

We have investigated the post-merger signatures of red-sequence galaxies in rich Abell clusters at z ≲ 0.1: A119, A2670, A3330, and A389. Deep images in u′, g′, r′, and medium-resolution galaxy spectra were taken using MOSAIC II CCD and Hydra MOS mounted on a Blanco 4 m telescope at Cerro Tololo Inter-American Observatory. Post-merger features are identified by visual inspection based on asymmetric disturbed features, faint structures, discontinuous halo structures, rings, and dust lanes. We found that ∼25% of bright (Mr < −20) cluster red-sequence galaxies show post-merger signatures in four clusters consistently. Most (∼71%) of the featured galaxies were found to be bulge dominated, and for the subsample of bulge-dominated red-sequence galaxies, the post-merger fraction rises to ∼38%. We also found that roughly 4% of bulge-dominated red-sequence galaxies interact (ongoing merger). A total of 42% (38% post-merger, 4% ongoing merger) of galaxies show merger-related features. Compared to a field galaxy study with a similar limiting magnitude by van Dokkum in 2005, our cluster study presents a similar post-merger fraction but a markedly lower ongoing merger fraction. The merger fraction derived is surprisingly high for the high density of our clusters, where the fast internal motions of galaxies are thought to play a negative role in galaxy mergers. The fraction of post-merger and ongoing merger galaxies can be explained as follows. Most of the post-merger galaxies may have carried over their merger features from their previous halo environment, whereas interacting galaxies interact in the current cluster in situ. According to our semi-analytic calculation, massive cluster halos may very well have experienced tens of halo mergers over the last 4–5 Gyr; post-merger features last that long, allowing these features to be detected in our clusters today. The apparent lack of dependence of the merger fraction on the clustocentric distance is naturally explained this way. In this scenario, the galaxy morphology and properties can be properly interpreted only when the halo evolution characteristics are understood first.
X-ray emission from the ultramassive black hole candidate NGC 1277: implications and speculations on its origin

We study the X-ray emission from NGC1277, a galaxy in the core of the Perseus cluster, for which van den Bosch et al. have recently claimed the presence of an UltraMassive Black Hole (UMBH) of mass 1.7 times 10^10 Msun, unless the IMF of the stars in the stellar bulge is extremely bottom heavy. The X-rays originate in a power-law component of luminosity 1.3 times 10^40 erg/s embedded in a 1 keV thermal minicorona which has a half-light radius of about 360 pc, typical of many early-type galaxies in rich clusters of galaxies. If Bondi accretion operated onto the UMBH from the minicorona with a radiative efficiency of 10 per cent, then the object would appear as a quasar with luminosity 10^46 erg/s, a factor of almost 10^6 times higher than observed. The accretion flow must be highly radiatively inefficient, similar to past results on M87 and NGC3115. The UMBH in NGC1277 is definitely not undergoing any significant growth at the present epoch. We note that there are 3 UMBH candidates in the Perseus cluster and that the inferred present mean mass density in UMBH could be 10^5 Msun/Mpc^3, which is 20 to 30 per cent of the estimated mean mass density of all black holes. We speculate on the implied growth of UMBH and their hosts, and discuss the possibiity that extreme AGN feedback could make all UMBH host galaxies have low stellar masses at redshifts around 3. Only those which end up at the centres of groups and clusters later accrete large stellar envelopes and become Brightest Cluster Galaxies. NGC1277 and the other Perseus core UMBH, NGC1270, have not however been able to gather more stars or gas owing to their rapid orbital motion in the cluster core.
Behavioural Intention to Use e-Wallet: The Perspective of Security and Trust

This study aims to determine the Behavioral intention (BI) to use E-wallets among the users. The model was developed based on the technology acceptance model (TAM). The study extended the model by examining the impact of Perceived security (PS) and Perceived trust (PT) beside the main TAM elements Perceived Ease of Use (PEOU) and Perceived Usefulness (PU). The data was collected from Iraqi citizens who have no experience with e-wallets. The data was collected by an online survey. 205 valid questionnaires were analyzed by the partial least squares technique. PEOU, PU, security, and trust has statistical positive value on BI to use e-wallets.
H i scaling relations of galaxies in the environment of H i-rich and control galaxies observed by the Bluedisk project

Our work is based on the 'Bluedisk' project, a programme to map the neutral gas in a sample of 25 HI-rich spirals and a similar number of control galaxies with the Westerbork Synthesis Radio Telescope (WSRT). In this paper, we focus on the H I properties of the galaxies in the environment of our targeted galaxies. In total, we extract 65 galaxies from the WSRT cubes with stellar masses between 10(8) and 10(11) M-circle dot. Most of these galaxies are located on the same H I mass-size relation and 'H I-plane' as normal spiral galaxies. We find that companions around H I-rich galaxies tend to be H I-rich as well and to have larger R-90, (H I)/R-50,R- H (I). This suggests a scenario of 'H I conformity', similar to the colour conformity found by Weinmann et al.: galaxies tend to adopt the HI properties of their neighbours. We visually inspect the outliers from the H I mass-size relation and galaxies which are offset from the H I plane and find that they show morphological and kinematical signatures of recent interactions with their environment. We speculate that these outliers have been disturbed by tidal or ram-pressure stripping processes, or in a few cases, by accretion events.