cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The distribution of B-site in the perovskite for a d5-d3 superexchange system studied with Molecular field theory and Monte Carlo simulation
Creators: name: Mo, Jiajun
name: Liu, Min
name: Xu, Shiyu
name: Zhang, Qinghang
name: Shen, Jiyu
name: Xia, Puyue
name: Xia, Yanfang
name: Jiang, Jizhou
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Atomic and Molecular Clusters (physics.atm-clus)
subject: FOS: Physical sciences

description: The B-site disorder in the d5 - d3 system of perovskites has been analyzed with molecular field theory and Monte Carlo method. The model is applicable to RFe1-pCrpO3 at any p value. When the saturation magnetization MS and phase transition temperature TP are known, a model can be built to calculate the order or disorder distribution of lattice B-sites. We analyze the case that the Fe-Cr superexchange is antiferromagnetic and ferromagnetic coupling respectively. The simulation result shows that the theoretical calculation formula is suitable for the calculation of different B-site distribution. Through the simulation, we find that when the x and y are large, the system will appear obvious long-range order. The DM interaction has a certain influence on the saturation magnetization. Via calculation, we found that the distribution states of Fe and Cr do not always conform to the uniform distribution but rather exhibit an effect that reduces the Fe-Fe clustering. The establishment of this model offers an explanation for several previously contentious issues, e.g., what is the phase transition temperature range of double perovskite, and why the different phase transition temperatures with the same doping proportion. It provides theoretical guidance for the design of functional materials with an arbitrary phase transition temperature.
AMBER-NACO aperture-synthesis imaging of the half-obscured central star and the edge-on disk of the red giant L2 Pup
Creators: name: Ohnaka, Keiichi
name: Schertl, Dieter
name: Hofmann, Karl-Heinz
name: Weigelt, Gerd
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The red giant L2 Pup started a dimming event in 1994, which is considered to be caused by the ejection of dust clouds. We present near-IR aperture-synthesis imaging of L2 Pup achieved by combining data from VLT/NACO speckle observations and long-baseline interferometric observations with the AMBER instrument of the Very Large Telescope Interferometer (VLTI). We also extracted an 8.7 micron image from the mid-IR VLTI instrument MIDI. Our aim is to spatially resolve the innermost region of the circumstellar environment. The diffraction-limited image at 2.27 micron obtained by bispectrum speckle interferometry with NACO with a spatial resolution of 57 mas shows an elongated component. The aperture-synthesis imaging combining the NACO speckle data and AMBER data (2.2--2.29 micron) with a spatial resolution of 5.6x7.3 mas further resolves not only this elongated component, but also the central star. The reconstructed image reveals that the elongated component is a nearly edge-on disk with a size of ~180x50 mas lying in the E-W direction, and furthermore, that the southern hemisphere of the central star is severely obscured by the equatorial dust lane of the disk. The angular size of the disk is consistent with the distance that the dust clouds that were ejected at the onset of the dimming event should have traveled by the time of our observations, if we assume that the dust clouds moved radially. This implies that the formation of the disk may be responsible for the dimming event. The 8.7 micron image with a spatial resolution of 220 mas extracted from the MIDI data taken in 2004 (seven years before the AMBER and NACO observations) shows an approximately spherical envelope without a signature of the disk. This suggests that the mass loss before the dimming event may have been spherical.
description: 11 pages, 11 figures, accepted for publication in Astronomy and Astrophysics
Semileptonic B_c decays to P-wave charmonia in the light-cone QCDSR
Creators: name: Akan, Tarik
name: Cincioglu, Elif
name: Ozpineci, Altug
name: Tegmen, Adnan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: B_c mesons are laboratories for probing heavy quark physics. Furthermore, they decay into charmonia and hence their decays can be used to analyze possible exotic charmonium. In this work, the semileptonic decays of B_c mesons into P wave charmonia are analysed using light cone QCD sum rules (LCSR). The distributions amplitudes for the charmonia are taken from a quark model computation. The obtained decay rates for the ground state and excited charmonia are compared with the results found in the literature.
description: 25 pages, 9 figures, 7 tables, minor changes, typos corrected
The non-singular Trautman-Kopczyński big-bang model and a torsional spinor description of dark matter
Creators: name: Cardoso, J. G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: A view is taken up whereby the non-singular Trautman-Kopczyński big-bang creation of the Universe produced a highly torsional hot state at early stages of the cosmic evolution which particularly brought about the formation of a dark matter cloud. It is thus assumed that the combination of Einstein-Cartan's theory with the torsionful version of the two-component ε-formalism of Infeld and van der Waerden supplies a natural local description of dark matter in terms of uncharged spin-one massive fields. In the case of either handedness, the pertinent spinor field equation arises directly from a suitable form of the world Bianchi identity. It appears that each such field equation bears a term that is thought of as carrying part of the information on the mass of the fields. The whole information turns out to be extracted by well prescribed derivatives of certain couplings involving the fields and spinor torsion pieces in such a way that the mass of dark matter is really thought of as arising from the interaction between the fields and spinor torsion.
description: Some strong suggestions have been made such that the comments made earlier should be withdrawn. The current version of the article is to appear in the European Physical Journal C
Studying the mechanisms of HP1-mediated heterochromatin formation and memory of repression
Creators: name: Bregio, Celyn
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2019

description: Heterochromatic pathways play a key role in the regulation of the genetic code. While there are numerous pathways that achieve the inactivation of specific genes, some have been evolutionarily conserved due to their effectiveness. One of the best examples of this is concept is Heterochromatin Protein 1 (HP1), which has been found to be a versatile protein that serves various roles across the genome. There are 3 different HP1 isoforms known to date: CBX5 (HP1α), CBX1 (HP1β), and CBX3 (HP1γ) that despite their similarities have been reported to behave differently. In this study, our aim is to determine the interplay between the identity of HP1 isoforms and their effect on the velocity and memory of gene repression. For this, we used a chromatin in vivo assay (CiA) system to chemically recruit HP1 to a reporter gene and study its effect. Our experimental data support the established notion that HP1α is a more efficient repressor than the other isoforms. Due to the collaborative relationship between biochemical activity, gene repression, and cellular memory, we believe that investigation of HP1 behavior can be relevant for the development of therapeutic drugs to treat genetically-linked diseases in which epigenetic misregulation often has a significant effect.
Large Brillouin Amplification in Silicon
Creators: name: Kittlaus, Eric A.
name: Shin, Heedeuk
name: Rakich, Peter T.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Strong Brillouin coupling has only recently been realized in silicon using a new class of optomechanical waveguides that yield both optical and phononic confinement. Despite these major advances, appreciable Brillouin amplification has yet to be observed in silicon. Using a new membrane-suspended silicon waveguide we report large Brillouin amplification for the first time, reaching levels greater than 5 dB for modest pump powers, and demonstrate a record low (5 mW) threshold for net amplification. This work represents a crucial advance necessary to realize high-performance Brillouin lasers and amplifiers in silicon.
Caring for Pachamama: Recommendations for Engaging with Agricultural Development
Creators: name: Whitfield, Emily
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: This research has led me to craft a guide for organizations that wish to engage with agricultural development in the developing world. Government agencies and NGOs in the international development sector that wish to support programs of agricultural development have a variety of options to choose from. These options range from efforts to increase yields through cash crop agriculture and chemicals to initiatives that prioritize environmental sustainability. This guide will explain the strengths and weaknesses of two seemingly opposing forms of agricultural development: the Green Revolution and indigenous agriculture. This information is located in chapters two and three, while chapter four will provide a case study of how an alternative, indigenous form of agricultural development was implemented in Northern Potosí, as an example of a successful program. Chapter five will explain the specific contexts in which one style of agriculture might be more effective than the other, and provide guidance to development organizations on the kind of agricultural program they should consider supporting based on the conditions of the area with which they are engaging.
Stronger 3SUM-Indexing Lower Bounds
Creators: name: Chung, Eldon
name: Larsen, Kasper Green
Publisher: name: arXiv
Year: 2022
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences
subject: E.1; F.2.0
subject: 68P05

description: The $3$SUM-Indexing problem was introduced as a data structure version of the $3$SUM problem, with the goal of proving strong conditional lower bounds for static data structures via reductions. Ideally, the conjectured hardness of $3$SUM-Indexing should be replaced by an unconditional lower bound. Unfortunately, we are far from proving this, with the strongest current lower bound being a logarithmic query time lower bound by Golovnev et al. from STOC'20. Moreover, their lower bound holds only for non-adaptive data structures and they explicitly asked for a lower bound for adaptive data structures. Our main contribution is precisely such a lower bound against adaptive data structures. As a secondary result, we also strengthen the non-adaptive lower bound of Golovnev et al. and prove strong lower bounds for $2$-bit-probe non-adaptive $3$SUM-Indexing data structures via a completely new approach that we find interesting in its own right.
description: SODA 2023
Household Food Insecurity in Al-Haymah Ad-Dakhiliyah district, Sana’a, Yemen: a mixed methods approach
Creators: name: Ajeen, Rawan
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2019

description: Food insecurity in Yemen is currently being addressed by numerous humanitarian organizations and global donations as an estimated 80% of those in Yemen require food assistance (FAO, 2017). This study aimed to answer whether traditional food insecurity trends are applicable in an emergency situation, such as the Yemeni humanitarian crisis. This study was a mixed methods approach, using quantitative and qualitative data, to recognize food insecurity trends in emergency situations and contextualize the food insecurity situation in Yemen. A secondary data analysis from War Child UK’s DRA4 Baseline Questionnaire (collected in July 2018) was used to address quantitative aims. Key Informant Interviews were conducted to better understand how food insecurity has impacted livelihoods of those in Yemen. Traditional food insecurity trends such as female headed household and IDP households being more vulnerable to household food insecurity was not observed by this study. However, explanatory variables such as access and coping strategies could account for a household’s food insecurity. This study concludes that majority of the households assessed in Al-Haymah Ad-Dakhiliyah are facing high levels of food insecurity, therefore in dire need of food assistance. The emergency food insecurity situation in Yemen has been exacerbated by the ongoing political clashes and conflict over the course of the past four years. Given the extent of famine, malnutrition, and inevitable food insecurity rates in the country, it is important to take into consideration a long-term solution, rather than long-term assistance to address this humanitarian crisis. The findings from this study further asserts the stance and solution that individuals in Yemen would like to see happen and humanitarian organization. The findings from this study can also provide background for further integration of emergency-complex situation models regarding food insecurity of humanitarian assistance intervention methods.
Topological self-dual configurations in a Maxwell--Higgs model with a CPT-odd and Lorentz-violating nonminimal coupling
Creators: name: Casana, Rodolfo
name: Ferreira, Manoel M.
name: Mota, Alexsandro Lucena
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We have studied the existence of topological self-dual configurations in a nonminimal CPT-odd and Lorentz-violating (LV) Maxwell-Higgs model, where the LV interaction is introduced by modifying the minimal covariant derivative. The Bogomol'nyi-Prasad-Sommerfield formalism has been implemented, revealing that the scalar self-interaction implying self-dual equations contains a derivative coupling. The CPT-odd self-dual equations describe electrically neutral configurations with finite total energy proportional to the total magnetic flux, which differ from the charged solutions of other CPT-odd and LV models previously studied. In particular, we have investigated the axially symmetrical self-dual vortex solutions altered by the LV parameter. For large distances, the profiles possess general behavior similar to the vortices of Abrikosov-Nielsen-Olesen. However, within the vortex core, the profiles of the magnetic field and energy can differ substantially from ones of the Maxwell-Higgs model depending if the LV parameter is negative or positive.
description: 8 pages, 13 figures, Latex2e
Two-Real-Singlet-Model Benchmark Planes
Creators: name: Robens, Tania
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this manuscript, I briefly review the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets that obey a Z2 x Z2' symmetry. In this model, all fields acquire a vacuum expectation value, such that the model contains in total 3 CP-even neutral scalars that can interact with each other. All interactions with SM-like particles are inherited from the SM-like doublet via mixing. I remind the readers of the previously proposed benchmark planes, and briefly discuss possible production at future Higgs factories, as well as regions in a more generic scan of the model. For these, I also discuss the use of the W-boson mass as a precision observable to determine allowed/ excluded regions in the models parameter space. This work builds on a whitepaper submitted to the Snowmass process.
description: 21 pages, 14 figures; extension of Whitepaper presented at arXiv:2205.14486; v2: slightly changed phrasing of abstract to clarify this is not a Snowmass Whitepaper; v3: minor changes, corresponds to published journal version
The Rhetoric of Persecution: Narratives of Witchcraft in Early Modern German Prints
Creators: name: Lee, Zachary
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2019

description: This thesis is about reframing the analysis of the German witch persecutions by exploring rhetoric and images in early modern German print media. The focus lies specifically on strategies of persuasion in pamphlets and broadsides published from 1589 to 1591. “The Rhetoric of Persecution” utilizes an interdisciplinary approach, drawing on sociological, historical, and literary concepts and frameworks. While the witch persecutions have long been a topic of historical study, there is less scholarship on the use of rhetorical devices in print media at the time and the potential effects of their use. Furthermore, many studies explore large-scale reasons behind the witch persecutions such as environmental and economic factors. In contrast, this thesis explores cultures of persecution by examining how media—and particularly printed works—incite fear and encourage the persecution of representative figures at which anxieties can be directed.
UV variability and accretion dynamics in the young open cluster NGC 2264
Creators: name: Venuti, Laura
name: Bouvier, Jerome
name: Irwin, Jonathan
name: Stauffer, John
name: Hillenbrand, Lynne
name: Rebull, Luisa
name: Cody, Ann Marie
name: Alencar, Silvia
name: Micela, Giuseppina
name: Flaccomio, Ettore
name: Peres, Giovanni
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We explore UV and optical variability signatures for several hundred members of NGC 2264 (3 Myr). We performed simultaneous u- and r-band monitoring over two full weeks with CFHT/MegaCam. About 750 young stars are probed; 40% of them are accreting. Statistically distinct variability properties are observed for accreting and non-accreting cluster members. The accretors exhibit a significantly higher level of variability than the non-accretors, especially in the UV. The amount of u-band variability correlates statistically with UV excess in disk-bearing objects, which suggests that accretion and star-disk interaction are the main sources of variability. Cool magnetic spots, several hundred degrees colder than the photosphere and covering from 5 to 30% of the stellar surface, appear to be the leading factor of variability for the non-accreting stars. In contrast, accretion spots, a few thousand degrees hotter than the photosphere and covering a few percent of the stellar surface, best reproduce the variability of accreting objects. The color behavior is also found to be different between accreting and non-accreting stars. Typical variability amplitudes for accreting members rapidly increase from r to u, which indicates a much stronger contrast at short wavelengths; a lower color dependence in the amplitudes is instead measured for diskless stars. We find that u-band variability on hour timescales is typically about 10% of the peak-to-peak variability on day timescales, while longer term (years) variability is consistent with amplitudes measured over weeks. We conclude that for both accreting and non-accreting stars, the mid-term rotational modulation by spots is the leading timescale for a variability of up to several years. In turn, this suggests that the accretion process is essentially stable over years, although it exhibits low-level shorter term variations in single accretion events.
description: 14 pages, 13 figures, accepted for publication in Astronomy & Astrophysics
Physics-/Model-Based and Data-Driven Methods for Low-Dose Computed Tomography: A survey
Creators: name: Xia, Wenjun
name: Shan, Hongming
name: Wang, Ge
name: Zhang, Yi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Machine Learning (cs.LG)
subject: Signal Processing (eess.SP)
subject: Medical Physics (physics.med-ph)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Since 2016, deep learning (DL) has advanced tomographic imaging with remarkable successes, especially in low-dose computed tomography (LDCT) imaging. Despite being driven by big data, the LDCT denoising and pure end-to-end reconstruction networks often suffer from the black box nature and major issues such as instabilities, which is a major barrier to apply deep learning methods in low-dose CT applications. An emerging trend is to integrate imaging physics and model into deep networks, enabling a hybridization of physics/model-based and data-driven elements. %This type of hybrid methods has become increasingly influential. In this paper, we systematically review the physics/model-based data-driven methods for LDCT, summarize the loss functions and training strategies, evaluate the performance of different methods, and discuss relevant issues and future directions.
Finite Dimensionality of the Global Attractor for the Solutions to 3D Primitive Equations with Viscosity
Creators: name: Ju, Ning
Publisher: name: arXiv
Year: 2015
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: A new method is presented to prove finiteness of the fractal and Hausdorff dimensions of the global attractor for the strong solutions to the 3D Primitive Equations with viscosity, which is applicable to even more general situations than the recent result of [7] in the sense that it removes all extra technical conditions imposed by previous analyses. More specifically, for finiteness of the dimensions of the global attractor, we only need the heat source $Q\in L^2$ which is exactly the condition for the existence of global strong solutions and the existence of the global attractor of these solutions; while the best existing result, which was obtained very recently in [7], still needs the extra condition that $\partial_z Q\in L^2 $ for finiteness of the dimensions of the global attractor. Moreover, the new method can be applied to cases with more complicated boundary conditions which present essential difficulties for previous methods.
Tetra-ethylene glycol coated gold nanoparticles are stable and have an extended half-life in vivo
Creators: name: Willett, Julian Daniel Sunday
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: Nanoparticles are becoming increasingly used in medicine as carriers of anti-tumor drugs. Published evidence suggests that they produce better patient outcomes than current delivery systems.  I have investigated a little studied nanoparticle coating, tetra-ethylene glycol (TEG), to determine if it provides pharmacologically relevant advantages, such as increased serum half-life and resistance to protein adsorption.  I compared the TEG-coated particles to those coated with glutathione (GSH), which are relatively unaltered in circulation and readily filtered by the kidney.  Nanoparticles coated with GSH and TEG were intravenously injected into mice and their half-lives and final destinations were determined via photometric analysis, light microscopy, and inductively coupled plasma mass spectrometry.  Protein adsorption, which facilitates macrophage phagocytosis of nanoparticles, was studied via column chromatography and gel electrophoresis.  I found that the GSH particles had a shorter half-life than the TEG particles (approximately 10 minutes versus 70 minutes) and predominantly accumulated in the kidney.  The TEG particles predominantly accumulated in the spleen and liver, although kidney proximal convoluted tubule cells also took them up.  The TEG particles were largely unaggregated in serum.  Those aggregates that did form, possibly by transient protein adsorption following ligand exchange reactions, were taken up by the spleen as shown by light microscopy.  These results demonstrate that TEG nanoparticles have an increased serum half-life and resistance to protein adsorption suggesting TEG could be an alternative to currently used coating agents.  TEG could prove a more efficient coat considering its minimal impact on nanoparticle size and its synthesis producing greatly mono-dispersed samples.
A new Directional Algebraic Fast Multipole Method based iterative solver for the Lippmann-Schwinger equation accelerated with HODLR preconditioner
Creators: name: Gujjula, Vaishnavi
name: Ambikasaran, Sivaram
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65R20, 65F55 (Primary) 31A10, 35J05, 35J08, 65R10 (Secondary)

description: We present a fast iterative solver for scattering problems in 2D, where a penetrable object with compact support is considered. By representing the scattered field as a volume potential in terms of the Green's function, we arrive at the Lippmann-Schwinger equation in integral form, which is then discretized using an appropriate quadrature technique. The discretized linear system is then solved using an iterative solver accelerated by Directional Algebraic Fast Multipole Method (DAFMM). The DAFMM presented here relies on the directional admissibility condition of the 2D Helmholtz kernel. And the construction of low-rank factorizations of the appropriate low-rank matrix sub-blocks is based on our new Nested Cross Approximation (NCA)~\cite{ arXiv:2203.14832 [math.NA]}. The advantage of our new NCA is that the search space of so-called far-field pivots is smaller than that of the existing NCAs. Another significant contribution of this work is the use of HODLR based direct solver as a preconditioner to further accelerate the iterative solver. In one of our numerical experiments, the iterative solver does not converge without a preconditioner. We show that the HODLR preconditioner is capable of solving problems that the iterative solver can not. Another noteworthy contribution of this article is that we perform a comparative study of the HODLR based fast direct solver, DAFMM based fast iterative solver, and HODLR preconditioned DAFMM based fast iterative solver for the discretized Lippmann-Schwinger problem. To the best of our knowledge, this work is one of the first to provide a systematic study and comparison of these different solvers for various problem sizes and contrast functions. In the spirit of reproducible computational science, the implementation of the algorithms developed in this article is made available at \url{https://github.com/vaishna77/Lippmann_Schwinger_Solver}.
description: 36 pages, 15 figures, 8 tables
Planar Josephson junctions in germanium: Effect of cubic spin-orbit interaction
Creators: name: Luethi, Melina
name: Laubscher, Katharina
name: Bosco, Stefano
name: Loss, Daniel
name: Klinovaja, Jelena
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Planar Josephson junctions comprising semiconductors with strong spin-orbit interaction (SOI) are promising platforms to host Majorana bound states (MBSs). Previous works on MBSs in planar Josephson junctions have focused on electron gases, where SOI is linear in momentum. In contrast, a two-dimensional hole gas in planar germanium (Ge) exhibits SOI that is cubic in momentum. Nevertheless, we show here that due to the particularly large SOI, Ge is a favorable material. Using a discretized model, we numerically simulate a Ge planar Josephson junction and demonstrate that also cubic SOI can lead to the emergence of MBSs. Interestingly, we find that the cubic SOI yields an asymmetric phase diagram as a function of the superconducting phase difference across the junction. We also find that trivial Andreev bound states can imitate the signatures of MBSs in a Ge planar Josephson junction, therefore making the experimental detection of MBSs difficult. We use experimentally realistic parameters to assess if the topological phase is accessible within experimental limitations. Our analysis shows that two-dimensional Ge is an auspicious candidate for topological phases.
Ordered state of magnetic charge in the pseudo-gap phase of a cuprate superconductor (HgBa2CuO4)
Creators: name: Lovesey, S. W.
name: Khalyavin, D. D.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: A symmetry-based interpretation of published experimental results demonstrates that the pseudo-gap phase of underdoped HgBa2CuO4(Hg1201) possesses an ordered state of magnetic charge epitomized by Cu magnetic monopoles. Magnetic properties of one-layer Hg1201 and two-layer YBa2Cu3O6 + x (YBCO) cuprates have much in common, because their pseudo-gap phases possess the same magnetic space-group, e.g., both underdoped cuprates allow the magneto-electric (Kerr) effect. Differences in their properties stem from different Cu site symmetries, leaving Cu magnetic monopoles forbidden in YBCO. Resonant x-ray Bragg diffraction experiments can complement the wealth of information available from neutron diffraction experiments on five Hg1201 samples on which our findings are based. In the case of Hg1201 emergence of the pseudo-gap phase, with time-reversal violation, is accompanied by a reduction of Cu site symmetry that includes loss of a centre of inversion symmetry. In consequence, parity-odd x-ray absorption events herald the onset of the enigmatic phase, and we predict dependence of corresponding Bragg spots on magneto-electric multipoles, including the monopole, and the azimuthal angle (crystal rotation about the Bragg wavevector).
Intersectionality and the Digital Divide in Guatemala: Internet Access Disparities and Maya Hackerdom in an Indigenous Lake Capital
Creators: name: Austin, Sofia
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: In reality, in both the United States and Guatemala, the current sociocultural context
includes inequality by intersecting factors such as race/ethnicity, gender, and class. The
intersectional approach is an academic perspective that acknowledges these multidimensional
factors, especially as experienced by women of color (e.g. Crenshaw 1989). When this inequality
persists in access to information and communication technology (ICT), a “digital divide” is
created between the empowered and the marginalized. This paper explores how the digital divide
is experienced and addressed by the local population of Sololá, based on my study of disparities
in Internet access through an intersectional lens.
Self-regulated AGN feedback of light jets in cool-core galaxy clusters
Creators: name: Ehlert, Kristian
name: Weinberger, Rainer
name: Pfrommer, Christoph
name: Pakmor, Rüdiger
name: Springel, Volker
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Heating from active galactic nuclei (AGN) is thought to stabilize cool-core clusters, limiting star formation and cooling flows. We employ radiative magneto-hydrodynamic (MHD) simulations to model light AGN jet feedback with different accretion modes (Bondi-Hoyle-Lyttleton and cold accretion) in an idealised Perseus-like cluster. Independent of the probed accretion model, accretion efficiency, jet density and resolution, the cluster self-regulates with central entropies and cooling times consistent with observed cool-core clusters in this non-cosmological setting. We find that increased jet efficiencies lead to more intermittent jet powers and enhanced star formation rates. Our fiducial low-density jets can easily be deflected by orbiting cold gaseous filaments, which redistributes angular momentum and leads to more extended cold gas distributions and isotropic bubble distributions. In comparison to our fiducial low momentum-density jets, high momentum-density jets heat less efficiently and enable the formation of a persistent cold-gas disc perpendicular to the jets that is centrally confined. Cavity luminosities measured from our simulations generally reflect the cooling luminosities of the intracluster medium (ICM) and correspond to averaged jet powers that are relatively insensitive to short periods of low-luminosity jet injection. Cold gas structures in our MHD simulations with low momentum-density jets generally show a variety of morphologies ranging from discy to very extended filamentary structures. In particular, magnetic fields are crucial to inhibit the formation of unrealistically massive cold gas discs by redistributing angular momentum between the hot and cold phases and by fostering the formation of elongated cold filaments that are supported by magnetic pressure.
description: 26 pages, 19 figures, published in MNRS
Should Investors Forecast Macroeconomic News Events? Effects of Perfect Foresight on Portfolio Sharpe Ratio
Creators: name: Moehring, Alex
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: This paper examines the portfolio response to scheduled macroeconomic news events
using both daily and high frequency data. This is accomplished by comparing Sharpe
ratios of portfolios formed using naive forecasting methods for expected return and
volatility with those formed using ex ante knowledge of the release value as an additional
term in the conditional mean and conditional variance equations. The workhorse
Autoregressive (AR(1)) and Generalized Autoregressive Conditional Heteroscedasticity
(GARCH(1,1)) models are utilized to forecast expected return and variance respectively.
The hypothetical portfolios are purchased at the end of the period before the
release, and exited at the end of the period containing the release. This paper finds
that in the time period 2002-2012 there is little evidence to support the claim that
knowledge of the macroeconomic news release value improves portfolio performance
at the daily frequency. For the five minute frequency, the additional knowledge only
significantly improved the portfolio performance for the CPI release.
The Effect Of Organizational Support On Work Satisfaction In Regional Secretariat Employees In Pariaman District
Creators: name: Saputra, Nika
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Employee Job Satisfaction
subject: Organizational Support

description: Human resources are one of the resources that exist in a company besides other resources, for example capital, materials, machinery in the company, so that it becomes useful. For this reason, companies are beginning to strive to excel in such competitive competition by trying to create quality and presentative human resources. This study aims to provide evidence that to determine whether or not there is an influence of organizational support on the work satisfaction of the Regional Secretariat Staff in Pariaman Regency. Data collection is done by survey method with a questionnaire. The data analysis technique used in this study is descriptive and quantitative analysis. The data collected is primary and secondary data which can be classified as independent variables and dependent variables. Organizational Support (influence variable), and Job Satisfaction in Regional Secretariat Staff of Pariaman Regency (affected variable). Testing the hypothesis in this study using a simple linear regression test. Based on the results of the study, it is known that there is a positive and significant influence between organizational support for and Job Satisfaction in the Regional Secretariat Staff of Pariaman Regency, obtained by a calculation that is greater than the Ttable where 2.806> 2.015 with a significance of 0.007 <0.05.
Analysis of Police Use of Force in the New York Stop and Frisk Policy
Creators: name: Alam, Ishrat Zarin
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2015

description: This study analyzes the Stop and Frisk policy in New York City to see if there is any evidence of racial profiling in force used by police officers. The study uses a logit model to estimate the probability of having force used on an individual conditional on being stopped. The probability of having force used on blacks and Hispanics is higher. A model specification with an interaction term between race of the suspect and crime rate of the precinct where the individual stopped further suggests that the difference in probability of force between blacks, Hispanics and whites is highest in low crime rate precincts. For precincts with higher crime rates the difference in probability between blacks, Hispanic and whites is lower.
Machine Learning and Deep Learning -- A review for Ecologists
Creators: name: Pichler, Maximilian
name: Hartig, Florian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Machine Learning (stat.ML)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences

description: 1. The popularity of Machine learning (ML), Deep learning (DL), and Artificial intelligence (AI) has risen sharply in recent years. Despite this spike in popularity, the inner workings of ML and DL algorithms are often perceived as opaque, and their relationship to classical data analysis tools remains debated. 2. Although it is often assumed that ML and DL excel primarily at making predictions, ML and DL can also be used for analytical tasks traditionally addressed with statistical models. Moreover, most recent discussions and reviews on ML focus mainly on DL, missing out on synthesizing the wealth of ML algorithms with different advantages and general principles. 3. Here, we provide a comprehensive overview of the field of ML and DL, starting by summarizing its historical developments, existing algorithm families, differences to traditional statistical tools, and universal ML principles. We then discuss why and when ML and DL models excel at prediction tasks and where they could offer alternatives to traditional statistical methods for inference, highlighting current and emerging applications for ecological problems. Finally, we summarize emerging trends such as scientific and causal ML, explainable AI, and responsible AI that may significantly impact ecological data analysis in the future. 4. We conclude that ML and DL are powerful new tools for predictive modeling and data analysis. The superior performance of ML and DL algorithms compared to statistical models can be explained by their higher flexibility and automatic data-dependent complexity optimization. However, their use for causal inference is still disputed as the focus of ML and DL methods on predictions creates challenges for the interpretation of these models. Nevertheless, we expect ML and DL to become an indispensable tool in E&E, comparable to other traditional statistical tools.
description: 62 pages, 10 figures
The Antheatres
Creators: name: Narendra Prasath
Publisher: name: Zenodo
Year: 2021
Subjects: Piracy
Movie Theatre
Antheatres
Antipiracy
Finacrapolo

description: Any unauthorized use for self, distribution, or trade of one’s copyrighted material in evasion from the fee of use is deliberated piracy. Apparently, a substantial count of real pirates had been long eradicated before now; the definition remained static. At present, the proclivity of piracy from a private attitude to a public behavior obliged us to reconcile this with a much more psychological viewpoint: Humans’ intrinsic behavior to share resources with personal intentions, often unsophisticated to make a profit yet capable of financially vandalizing the subject for fame in anonymity; alongside with a so-called ideology of free digital media. Secondary to The Antheatres, the primary intention here is to show where piracy is headed than to propose a panacea. Using numerical data and experimental parameters, here demonstrated a model that implies existing infrared technology to forbade movie pirates from recording the in-theatres movie, let alone marring rendered movie. Of course, I could not do this alone, or I alone could do this; It is a huge picture from above, and I just help connect the dots of my part below. In the end, I hope someone takes this pen from where I left it.
description: My debut as a scholarly writer in the field of astonishing sciences.
Ground-state electronic structure of quasi-one-dimensional wires in semiconductor heterostructures
Creators: name: Owen, E. T.
name: Barnes, C. H. W.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We apply density functional theory, in the local density approximation, to a quasi-one-dimensional electron gas in order to quantify the effect of Coulomb and correlation effects in modulating, and therefore patterning, the charge density distribution. Our calculations are presented specifically for surface-gate-defined quasi-one-dimensional quantum wires in a GaAs-AlGaAs heterostructure but we expect our results to apply more generally for other low dimensional semiconductor systems. We show that at high densities with strong confinement, screening of electrons in the direction transverse to the wire is efficient and density modulations are not visible. In the low-density, weak-confinement regime, the exchange-correlation potential induces small density modulations as the electrons are depleted from the wire. At the weakest confinements and lowest densities, the electron density splits into two rows thereby forming a pair of quantum wires that lie beneath the surface gates. An additional double-well external potential forms at very low density which enhances this row splitting phenomenon. We produce phase diagrams that show a transition between the presence of a single quantum wire in a split-gate structure and two quantum wires. We suggest that this phenomenon can be used to pattern and modulate the electron density in low-dimensional structures with particular application to systems where a proximity effect from a surface gate would be valuable.
description: 12 pages, 7 figures
Ba{0.4}Rb{0.6}Mn2As2: A Prototype Half-Metallic Ferromagnet
Creators: name: Pandey, Abhishek
name: Johnston, D. C.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Half-metallic ferromagnetism (FM) in single-crystal Ba{0.39(1)}Rb{0.61(1)}Mn2As2 below its Curie temperature TC = 103(2) K is reported. The magnetization M versus applied magnetic field H isotherm data at 1.8 K show complete polarization of the itinerant doped-hole magnetic moments that are introduced by substituting Rb for Ba. The material exhibits extremely soft FM, with unobservably small remanent magnetization and coercive field. Surprisingly, and contrary to typical itinerant FMs, the M(H) data follow the Arrott-plot paradigm that is based on a mean-field theory of local-moment FMs. The in-plane electrical resistivity data are fitted well by an activated-T^2 expression for T < TC, whereas the data sharply deviate from this model for T > TC. Hence the activated-T^2 resistivity model is an excellent diagnostic for determining the onset of half-metallic FM in this compound, which in turn demonstrates the presence of a strong correlation between the electronic transport and magnetic properties of the material. Together with previous data on 40% hole-doped Ba{0.6}K{0.4}Mn2As2, these measurements establish 61%-doped Ba{0.39}Rb{0.61}Mn2As2 as a prototype for a new class of half-metallic ferromagnets in which all the itinerant carriers in the material are ferromagnetic.
description: 5 pages, 6 figures
DR.BENCH: Diagnostic Reasoning Benchmark for Clinical Natural Language Processing
Creators: name: Gao, Yanjun
name: Dligach, Dmitriy
name: Miller, Timothy
name: Caskey, John
name: Sharma, Brihat
name: Churpek, Matthew M
name: Afshar, Majid
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: The meaningful use of electronic health records (EHR) continues to progress in the digital era with clinical decision support systems augmented by artificial intelligence. A priority in improving provider experience is to overcome information overload and reduce the cognitive burden so fewer medical errors and cognitive biases are introduced during patient care. One major type of medical error is diagnostic error due to systematic or predictable errors in judgment that rely on heuristics. The potential for clinical natural language processing (cNLP) to model diagnostic reasoning in humans with forward reasoning from data to diagnosis and potentially reduce the cognitive burden and medical error has not been investigated. Existing tasks to advance the science in cNLP have largely focused on information extraction and named entity recognition through classification tasks. We introduce a novel suite of tasks coined as Diagnostic Reasoning Benchmarks, DR.BENCH, as a new benchmark for developing and evaluating cNLP models with clinical diagnostic reasoning ability. The suite includes six tasks from ten publicly available datasets addressing clinical text understanding, medical knowledge reasoning, and diagnosis generation. DR.BENCH is the first clinical suite of tasks designed to be a natural language generation framework to evaluate pre-trained language models. Experiments with state-of-the-art pre-trained generative language models using large general domain models and models that were continually trained on a medical corpus demonstrate opportunities for improvement when evaluated in DR. BENCH. We share DR. BENCH as a publicly available GitLab repository with a systematic approach to load and evaluate models for the cNLP community.
description: Under review
Health Care Disparities Among Latinx Migrant Field Workers: A Literature Review
Creators: name: Garcia, Sandra
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2019

description: Despite being one of the fastest growing populations in the United States, the health of migrant agricultural workers often goes unnoticed. The purpose of this literature review was to understand the health care disparities experienced by Latinx migrant farmworkers related to pesticide exposures in their occupation. This project specifically focuses on the Latinx migrant community. The term Latinx was selected as it is an all-inclusive term with no limitations based on gender. The migrant community consists of people who relocated to the United States from Central and South America and now work in the agricultural occupations. Analysis of the research gathered engages the possibility of interventions to promote health equity among this community and cultural competent care needed in the context of nursing to improve the health disparities for the Latinx migrant farmworker population.
Irregularity of the Bergman projection on smooth unbounded worm domains
Creators: name: Krantz, Steven G.
name: Monguzzi, Alessandro
name: Peloso, Marco M.
name: Stoppato, Caterina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 32A25, 32A36

description: In this work we consider smooth unbounded worm domains $\mathcal Z_λ$ in $\mathbb C^2$ and show that the Bergman projection, densely defined on the Sobolev spaces $H^{s,p}(\mathcal Z_λ)$, $p\in(1,\infty)$, $s\ge0$, does not extend to a bounded operator $P_λ:H^{s,p}(\mathcal Z_λ)\to H^{s,p}(\mathcal Z_λ)$ when $s>0$ or $p\neq2$. The same irregularity was known in the case of the non-smooth unbounded worm. This improved result shows that the irregularity of the projection is not a consequence of the irregularity of the boundary but instead of the infinite windings of the worm domain.
description: Revised version. To appear on the Mediterranean Journal of Mathematics