Miracle-dz/UniFAR-FTUs huggingface dataset:
Ab initio Computation of the Static Exchange–Correlation Kernel of Real Materials: From Ambient Conditions to Warm Dense Matter

The electronic exchange—correlation (XC) kernel constitutes a fundamental input for the estimation of a gamut of material properties such as the dielectric characteristics, the thermal and electrical conductivity, the construction of eﬀective potentials, or the response to an external perturbation. In practice, no reliable method has been known that allows to compute the kernel of real materials. In this work, we overcome this long-standing limitation by introducing a new, formally exact methodology for the computation of the static XC kernel of arbitrary materials exclusively within the framework of density functional theory (DFT)—no external input apart from the usual XC-functional is required. As a ﬁrst practical demonstration of the utility and ﬂexibility of our methodology, we compare our new results with exact quantum Monte Carlo (QMC) data for the archetypical uniform electron gas model at both ambient and warm dense matter conditions. This gives us unprecedented insights into the performance of diﬀerent XC-functionals, and has important implications for the development of new functionals that are designed for the application at extreme temperatures. In addition, we obtain new DFT results for the XC kernel of warm dense hydrogen as it occurs in fusion applications and astrophysical objects such as planetary interiors. The observed excellent agreement to the recent QMC results by B¨ohme et al. [Phys. Rev. Lett. 129 , 066402 (2022)] clearly demonstrates that our framework is capable to even capture nontrivial eﬀects such as XC-induced isotropy breaking in the density response of hydrogen at large wave numbers. Our method can easily be applied using standard DFT codes and will open up new avenues for the computation of the properties of real materials.
How Developers Extract Functions: An Experiment

Creating functions is at the center of writing computer programs. But there has been little empirical research on how this is done and what are the considerations that developers use. We design an experiment in which we can compare the decisions made by multiple developers under exactly the same conditions. The experiment is based on taking existing production code,"flattening"it into a single monolithic function, and then charging developers with the task of refactoring it to achieve a better design by extracting functions. The results indicate that developers tend to extract functions based on structural cues, such as 'if' or 'try' blocks. And while there are significant correlations between the refactorings performed by different developers, there are also significant differences in the magnitude of refactoring done. For example, the number of functions that were extracted was between 3 and 10, and the amount of code extracted into functions ranged from 37% to 95%.
Finite-temperature tensor network study of the Hubbard model on an infinite square lattice

The Hubbard model is a longstanding problem in the theory of strongly correlated electrons and a very active one in the experiments with ultracold fermionic atoms. Motivated by current and prospective quantum simulations, we apply a two-dimensional tensor network, an infinite projected entangled pair state, evolved in imaginary time by the neighborhood tensor update algorithm working directly in the thermodynamic limit. With U(1)xU(1) symmetry and the bond dimensions up to 29, we generate thermal states down to the temperature of 0.17 times the hopping rate. We obtain results for spin and charge correlators, unaffected by boundary effects. The spin correlators, measurable in prospective ultracold atoms experiments attempting to approach the thermodynamic limit, provide evidence of disruption of the antiferromagnetic background with mobile holes in a slightly doped Hubbard model. The charge correlators reveal the presence of hole-doublon pairs near half filling and signatures of hole-hole repulsion on doping. We also obtain specific heat in the slightly doped regime.
XFL: Naming Functions in Binaries with Extreme Multi-label Learning

Reverse engineers benefit from the presence of identifiers such as function names in a binary, but usually these are removed for release. Training a machine learning model to predict function names automatically is promising but fundamentally hard: unlike words in natural language, most function names occur only once. In this paper, we address this problem by introducing eXtreme Function Labeling (XFL), an extreme multi-label learning approach to selecting appropriate labels for binary functions. XFL splits function names into tokens, treating each as an informative label akin to the problem of tagging texts in natural language. We relate the semantics of binary code to labels through Dexter, a novel function embedding that combines static analysis-based features with local context from the call graph and global context from the entire binary. We demonstrate that XFL/Dexter outperforms the state of the art in function labeling on a dataset of 10,047 binaries from the Debian project, achieving a precision of 83.5%. We also study combinations of XFL with alternative binary embeddings from the literature and show that Dexter consistently performs best for this task. As a result, we demonstrate that binary function labeling can be effectively phrased in terms of multi-label learning, and that binary function embeddings benefit from including explicit semantic features.
Polarization and its discontents: How polarized foregrounds affect 21cm epoch of reionization measurements

As the first luminous objects began to form, they heated their surrounding medium, ionizing it. This event is the most recent cosmic phase transition, and occured during what is called the Epoch of Reionization (EoR). The ionization history of the intergalactic medium can be directly measured by 21cm emission from the hyperfine transition of hydrogen. Measurments of the 21cm signal from the EoR can yield information about those first luminous objects and help complete our understanding of cosmic history. Today, we measure the 21cm EoR signal in radio frequencies. Excavating the 21cm EoR signal from beneath the bright foregrounds present at meter wavelengths requires pristine characterization of all foregrounds. We discuss how spectrally smooth foregrounds are isolated to particular regions of the 21cm EoR power spectrum, but Faraday-rotated, polarized sources can contaminate all regions, even those typically reserved for the 21cm EoR signal. To estimate the level of contamination we can expect from polarized foregrounds, we create a physically motivated simulation of the polarized sky at these wavelengths. These simulations imply that polarized foregrounds will contaminate the power spectrum at levels much higher than the 21cm signal. To confirm the theories we develop in simulation, we turn to data taken with the Donald C. Backer Precision Array to Probe the Epoch of Reionization (PAPER), an array of antennae operating from 100 to 200 MHz in the Karoo desert of South Africa. Using data taken during a six month deployment with PAPER elements configured into an 8 Ã? 4 grid, we measure the power spectrum of all four Stokes parameters. The measured Q power spectrum exceeds its simulated values, allowing us to constrain the input parameters to the simulations. In particular, we are able to limit the mean polarized fraction of sources to 2.2 Ã? 10-3 , a factor of ten lower than existing measurements at 1.4 GHz, on which we based the simulations. Finally, we present three new tools for characterizing polarized foregrounds. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Physics & Astronomy First Advisor James E. Aguirre Subject Categories Astrophysics and Astronomy | Physics This dissertation is available at ScholarlyCommons: http://repository.upenn. edu/edissertations/1375 POLARIZATION AND ITS DISCONTENTS: HOW POLARIZED FOREGROUNDS AFFECT 21CM EPOCH OF REIONIZATION MEASUREMENTS David F. Moore A DISSERTATION in Physics and Astronomy Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy
Chandra View of Kesteven 79: A Nearly Isothermal Supernova Remnant with Rich Spatial Structure

A 30 ks Chandra ACIS-I observation of Kes 79 reveals rich spatial structures, including many filaments, three partial shells, a loop, and a "protrusion. " Most of them have corresponding radio features. Regardless of the different results from two nonequilibrium ionization (NEI) codes, temperatures of different parts of the remnant are all around 0.7 keV, which is surprisingly constant for a remnant with such rich structure. If thermal conduction is responsible for smoothing the temperature gradient, a lower limit on the thermal conductivity of ~1/10 of the Spitzer value can be derived. Thus, thermal conduction may play an important role in the evolution of at least some supernova remnants (SNRs). No spectral signature of the ejecta is found, which suggests that the ejecta material has been well mixed with the ambient medium. From the morphology and the spectral properties, we suggest that the bright inner shell is a wind-driven shell (WDS) overtaken by the blast wave (the outer shell) and estimate the age of the remnant to be ~6 kyr for the assumed dynamics. Projection is also required to explain the complicated morphology of Kes 79.
Note on Solution for Plane Oseen Flow Past a Semi -infinite Plate

The solution for viscous incompressible flow past a semi-infinite flat plate aligned with the flow are obtained under Oseen's approximation. The problem has been reduced to the solution of an integral equation which in turn reduce to the solution of a Reiman Hilbert boundary value problem. The boundary value problem has, ultimately, been solved by standard technique as sought by Gakhov.
Stable Configurations of Linear Subspaces and Quotient Coherent Sheaves

In this paper we provide some stability criteria for systems of linear subspaces of $V \otimes W$ and for systems of quotient coherent sheaves, using, respectively, the Hilbert-Mumford numerical criterion and moment map. Along the way, we generalize the Gelfand-MacPherson correspondence [11] from point sets to sets of linear subspaces (of various dimensions). And, as an application, we provide some examples of $G$-ample cones without any top chambers. The results of this paper are based upon and/or generalize some earlier works of Klyachko [18], Totaro [28], Gelfand-MacPherson [11], Kapranov [17], Foth-Lozano [8], Simpson [24], Wang [30], Phong-Sturm [22], Zhang [32] and Luo [20], among others.
Prevalence study of type 2 diabetes mellitus in the Ashanti region of Ghana: a systematic review of risk factors

Introduction: The prevalence and risk factors of type 2 diabetes vary across the urban and rural milieus of Ghana's Ashanti Region, yet no study has been conducted to synthesise the available studies. Methods: A comprehensive literature search was carried out in PubMed, CINAHL, Scopus and Web of Science with hand searches in Google Scholar and grey literature between May 15, 2021 and June 30, 2021. Searches were made for articles published between January 1, 2011 and December 31, 2020 on type 2 diabetes mellitus in the Ashanti region of Ghana. MeSH terms and keywords, separated by some Boolean operators, were used. Results: The searches yielded a total of 268 articles, of which 12 studies were selected for the final review. Physical inactivity and obesity were identified as the major risk factors of type 2 diabetes in the region. Higher prevalence of the disease was also identified in females. More so, in terms of rural and urban divides, type 2 diabetes mellitus was found predominantly among urban dwellers. Conclusion: Findings from the study call for mass sensitisation and awareness creation in respect of diabetes, to ensure that people are well informed on the dynamics of the disease in the region and, by extension, the country at large.
Testing Non‐Correlation and Non‐Causality between Multivariate ARMA Time Series

Abstract. Haugh [Journal of the American Statistical Association (1976) Vol. 71, pp. 378–85] developed an approach to the problem of testing non‐correlation (at all leads and lags) between two univariate time series. Haugh's tests however have low power against two series which are related over a long distributed lag when individual lag coefficients are relatively small. As a remedy, Koch and Yang [Journal of the American Statistical Association (1986) Vol. 8, pp. 533–44] proposed an alternative method that performs better than Haugh's under such dependencies. A multivariate extension of Haugh's procedure was proposed by El Himdi and Roy [The Canadian Journal of Statistics (1997) Vol. 25, pp. 233–56], but suffers the same weaknesses as the original univariate method. We develop here an asymptotic test generalizing Koch and Yang's method to the multivariate case. Our method includes El Himdi and Roy's as a special case. Based on the same idea, we also suggest a generalization of the El Himdi and Roy procedure for testing causality in the sense of Granger [Econometrica (1969) Vol. 37, pp. 424–38] between two multivariate series. A Monte Carlo study is conducted, which indicates that our approach performs better than El Himdi and Roy's for a wide range of models. Both procedures are applied to the problem of testing the absence of correlation between Canadian and US economic indicators, and to a brief study of causality between money and income in Canada.
Colour vision in thrips (Thysanoptera)

Insects are an astonishingly successful and diverse group, occupying the gamut of habitats and lifestyle niches. They represent the vast majority of described species and total terrestrial animal biomass on the planet. Their success is in part owed to their sophisticated visual systems, including colour vision, which drive a variety of complex behaviours. However, the majority of research on insect vision has focused on only a few model organisms including flies, honeybees and butterflies. Especially understudied are phytophagous insects, such as diminutive thrips (Thysanoptera), in spite of their damage to agriculture. Thrips display robust yet variable colour-specific responses despite their miniaturized eyes, but little is known about the physiological and ecological basis of their visual systems. Here, we review the known visual behavioural information about thrips and the few physiological studies regarding their eyes. Eye structure, spectral sensitivity, opsin genes and the presence of putative colour filters in certain ommatidia strongly imply dynamic visual capabilities. Finally, we discuss the major gaps in knowledge that remain for a better understanding of the visual system of thrips and why bridging these gaps is important for expanding new possibilities for applied pest management strategies for these tiny insects. This article is part of the theme issue ‘Understanding colour vision: molecular, physiological, neuronal and behavioural studies in arthropods’.
Women’s access to health care for non-communicable diseases in South Africa: A scoping review. [version 1; peer review: awaiting peer review]

Background : Non-communicable diseases (NCDs) such as obesity, hypertension (HPT), and type II diabetes (T2D) are of increasing concern in South Africa (SA), with women being more at risk. Authors conducted a scoping review to identify and map the evidence available about the barriers of access to obesity, HPT, and T2D care among women in SA. Methods: Arksey and O'Malley's framework for scoping review was used. The search of the literature was completed in the Scopus, Web of Science, and PubMed databases between April and May 2022. Only studies conducted among women in SA were eligible for inclusion. Identified barriers were mapped onto Levesque’s framework of access to health care to determine which points along the chain of accessing NCD health perception of need to benefitting from care. Articles included identified barriers affecting the availability and accommodation dimension of access to care, suggesting that HPT and T2D care is often unavailable or that women are unable to reach health facilities or service providers. There is need for more and better-quality research about access to NCD health care in SA, especially among women having a disproportionately high burden of obesity, T2D, and HPT.
Fundamentals of Plasma Physics: Intuitive method for vector calculus identities

Preface 1. Basic concepts 2. The Vlasov, two-fluid, and MHD models of plasma dynamics 3. Motion of a single plasma particle 4. Elementary plasma waves 5. Streaming instabilities and the Landau problem 6. Cold plasma waves in a magnetized plasma 7. Waves in inhomogeneous plasmas and wave energy relations 8. Vlasov theory of warm electrostatic waves in a magnetized plasma 9. MHD equilibria 10. Stability of static MHD equilibria 11. Magnetic helicity interpreted and Woltjer-Taylor relaxation 12. Magnetic reconnection 13. Fokker-Planck theory of collisions 14. Wave-particle nonlinearities 15. Wave-wave nonlinearities 16. Non-neutral plasmas 17. Dusty plasmas Appendix A. Intuitive method for vector calculus identities Appendix B. Vector calculus in orthogonal curvilinear coordinates Appendix C. Frequently used physical constants and formulae Bibliography References Index.
Generalizing Cross Products and Maxwell's Equations to Universal Extra Dimensions

In the past five years, there has been considerable research on the collider phenomenology of TeV-scale extra compact dimensions which are universal - i.e. accessible to all the Standard Model fields. We consider in detail a fundamental conceptual issue in the higher-dimensional theory: Since the cross product is only physically meaningful in three spatial dimensions, how do traditional vector formulas involving the cross product or curl operation generalize in the case of universal extra dimensions? For example, is angular momentum physically meaningful, and, if so, how is it related to the position and momentum vectors? We find that if angular velocity, torque, angular momentum, and magnetic field, for example, are regarded as anti-symmetric second-rank tensors instead of pseudovectors, we can construct tensor forms of the standard cross product and curl equations that do generalize to higher dimensions. Although Maxwell's equations have been generalized to extra dimensions in terms of differential forms, we show that our simple technique casts the generalized Maxwell's equations in a form very similar to the standard vector calculus. We also provide direct integrals for the fields in a practical tensor calculus form. We explore the electric and magnetic fields in detail to show that there are no fundamental conceptual problems hidden in the theory - e.g. how the Lorentz force can be meaningfully expressed in terms of the velocity and magnetic field when the traditional cross product and right-hand rule do not apply. Finally, we explore the effects that compactification has on the effective form of Maxwell's equations, which could be useful for direct tests of Coulomb's law.
Structural and multiferroic properties of BiFeO3 thin films at room temperature

BiFeO3 thin films have been prepared on Pt∕TiO2∕SiO2∕Si substrates under various oxygen pressures of 0.15–0.005Torr at a temperature of 450°C by pulsed-laser deposition. The effects of deposition pressure on their crystal structure and multiferroic properties have been investigated at room temperature. X-ray diffraction analysis (θ-2θ scans and 2-dimensional scans) shows that the BiFeO3 thin films consist of perovskite single phase with tetragonal crystal structure and space group P4mm. The c-axis lattice constant decreases (4.062–4.006A) and c∕a ratio of the films decreases from 1.032 to 1.014 with a decrease in the oxygen pressure. The surface roughness and grain size of the films depend dramatically on oxygen pressures. The dielectric constant of the films decreases with decreasing oxygen pressure. The film deposited at 0.05Torr shows a stable current density and well-saturated hysteresis loop with twice the remanent polarization (2Pr) of 136μC∕cm2 and coercive field (2Ec) of 109kV∕cm. The BiFeO3 thin .
Chandra X-Ray Observatory Study of Vela Shrapnel A

We present high-resolution Chandra observations of shrapnel A in the vicinity of the Vela supernova remnant. The Chandra image reveals a bright X-ray region at the head position of shrapnel A and a fainter extended tail. The spectral analysis shows that the plasma is in a condition of nonequilibrium ionization. The abundance of O is 0.34 times that of the solar value, whereas that of Si is 3 times solar, showing an anomalous abundance ratio for the two elements. The ionization timescale indicates that the shrapnel had been heated up about 104 yr ago. We confirm that the pressure in the head region is ≃10 times higher than that in the tail region, which is not explained by a simple blast-wave model. These facts strongly support the view that shrapnel A is a fragment of the progenitor star created in the supernova explosion.
Test‐particle simulation of energetic electron‐H2O elastic collision along Saturn's magnetic field line around Enceladus

We examine the variation of energetic electron pitch angle distribution at the magnetic equator and loss rate of precipitated electrons into Saturn's atmosphere through pitch angle scattering due to elastic collisions with neutral H2O along Saturn's magnetic field line around Enceladus. To examine the variation of those, we perform one‐dimensional test‐particle simulation when the co‐rotating electron flux tube passes through the dense H2O region in the vicinity of Enceladus (~6.4 min). We focus on 1 keV as a typical kinetic energy of the electrons in this study. The initial pitch angle distribution is assumed to be isotropic. Results show that the equatorial electron pitch angle distribution near the loss cone (<20° and >160°) decreases with time through pitch angle scattering due to elastic collisions. It is found that the electrons of ~11.4% to the total number of equatorial electrons at the initial condition are lost in ~380 s. The calculated loss time is twice faster than the loss time under the strong diffusion.