cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spatially Resolved Magnetic Field Structure in the Disk of a T Tauri Star
Creators: name: Stephens, Ian W.
name: Looney, Leslie W.
name: Kwon, Woojin
name: Fernández-López, Manuel
name: Hughes, A. Meredith
name: Mundy, Lee G.
name: Crutcher, Richard M.
name: Li, Zhi-Yun
name: Rao, Ramprasad
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Magnetic fields in accretion disks play a dominant role during the star formation process but have hitherto been observationally poorly constrained. Field strengths have been inferred on T Tauri stars themselves and possibly in the innermost part of the accretion disk, but the strength and morphology of the field in the bulk of the disk have not been observed. Unresolved measurements of polarized emission (arising from elongated dust grains aligned perpendicular to the field) imply average fields aligned with the disks. Theoretically, the fields are expected to be largely toroidal, poloidal, or a mixture of the two, which imply different mechanisms for transporting angular momentum in the disks of actively accreting young stars such as HL Tau. Here we report resolved measurements of the polarized 1.25 mm continuum emission from HL Tau's disk. The magnetic field on a scale of 80 AU is coincident with the major axis (~210 AU diameter) of the disk. From this we conclude that the magnetic field inside the disk at this scale cannot be dominated by a vertical component, though a purely toroidal field does not fit the data well either. The unexpected morphology suggests that the magnetic field's role for the accretion of a T Tauri star is more complex than the current theoretical understanding.
description: Accepted for publication in Nature
Improving our understanding of the Klein-Gordon equation
Creators: name: Bussey, P. J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A detailed consideration of the Klein-Gordon equation in relativistic quantum mechanics is presented in order to offer more clarity than many standard approaches. The equation is frequently employed in the research literature, even though problems have often been raised regarding its second-order nature, the status of its negative-energy solutions and the formulation of particle density and flux. Most of these problems can be avoided by dismissing the negative-energy solutions. An application of the equation to a broad wave-packet shows that a small amendment to the usual relativistic formalism can be helpful to demonstrate continuity with the non-relativistic case, although difficulties remain when the proposed quantum state has a broad relativistic energy distribution.
description: 9 pages
Wettability and heat transfer enhancement associated with electrostatic suppression of the Leidenfrost state
Creators: name: Özkan, Onur
name: 0000-0002-4712-2182
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: Leidenfrost
Droplet
Electrowetting
Boiling
Heat transfer
Film boiling
Electrostatic suppression
Leidenfrost state suppression

description: The well-known Leidenfrost effect refers to a liquid drop levitating on its own vapor on a sufficiently hot surface. The Leidenfrost effect severely reduces heat transfer due to the insulating nature of the vapor layer. Application of an electrical potential difference across the vapor gap suppresses the Leidenfrost state by electrostatically attracting liquid towards the surface. The resulting transient solid-liquid contacts significantly reduce the thermal resistance to heat transfer across the vapor gap. This dissertation is a fundamental study of the wettability and heat transfer enhancement associated with electrostatic suppression of the Leidenfrost state. Chapter 1 details the motivation for this study and the objectives of this dissertation. Chapter 2 includes a literature review on relevant topics in boiling heat transfer and Leidenfrost droplets. Chapter 3 details a study on the influence of the frequency of the applied AC waveform on electrostatic suppression. This study involved high speed visualization of liquid-vapor instabilities and heat transfer measurements associated with evaporating droplets. Chapter 4 develops electrical impedance characterization as a powerful tool to measure the wetted fraction during suppression, and to estimate the threshold voltage for suppression. The statistical nature of wetting is highlighted and the influence of the electric field, superheat, and size of the Leidenfrost pool on the wetted area is quantified. Chapter 5 details a study on heat transfer enhancement accompanying electrostatic suppression of the Leidenfrost state. A first principles-based multiphysics analytical model is developed to predict heat transfer enhancement and is validated by heat flux measurements under electrostatic suppression. Chapter 6 is a fundamental study (experiments, numerical simulations) of vapor dome formation and bubble breakthrough in large Leidenfrost droplets under the influence of an electric field. Chapter 7 summarizes key conclusions and outlines suggestions for future work. Overall, this dissertation has led to stimulating contributions in the field of boiling heat transfer. This multidisciplinary work has involved experiments, analytical modeling and numerical simulations. The results show that electric fields make the critical heat flux (CHF) limit irrelevant and can reshape the boiling curve. This research impacts applications in energy production (solar-thermal, steam generation) and materials processing (quenching).
MC^2: Galaxy Imaging and Redshift Analysis of the Merging Cluster CIZA J2242.8+5301
Creators: name: Dawson, William A.
name: Jee, M. James
name: Stroe, Andra
name: Ng, Y. Karen
name: Golovich, Nathan
name: Wittman, David
name: Sobral, David
name: Bruggen, Marcus
name: Rottgering, H. J. A.
name: van Weeren, R. J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: X-ray and radio observations of CIZA J2242.8+5301 suggest that it is a major cluster merger. Despite being well studied in the X-ray, and radio, little has been presented on the cluster structure and dynamics inferred from its galaxy population. We carried out a deep (i<25) broad band imaging survey of the system with Subaru SuprimeCam (g & i bands) and the Canada France Hawaii Telescope (r band) as well as a comprehensive spectroscopic survey of the cluster area (505 redshifts) using Keck DEIMOS. We use this data to perform a comprehensive galaxy/redshift analysis of the system, which is the first step to a proper understanding the geometry and dynamics of the merger, as well as using the merger to constrain self-interacting dark matter. We find that the system is dominated by two subclusters of comparable richness with a projected separation of 6.9'^{+0.7}_{-0.5} (1.3^{+0.13}_{-0.10} Mpc). We find that the north and south subclusters have similar redshifts of z=0.188 with a relative line-of-sight velocity difference of 69+/-190 km/s. We also find that north and south subclusters have velocity dispersions of 1160^{+100}_{-90} km/s and 1080^{+100}_{-70} km/s, respectively. These correspond to masses of 16.1^{+4.6}_{-3.3}x10^14 M_sun and 13.0^{+4.0}_{-2.5}x10^14 M_sun, respectively. While velocity dispersion measurements of merging clusters can be biased we believe the bias in this system to be minor due to the large projected separation and nearly plane-of-sky merger configuration. CIZA J2242.8+5301 is a relatively clean dissociative cluster merger with near 1:1 mass ratio, which makes it an ideal merger for studying merger associated physical phenomena.
description: 17 pages, 14 figures, submitted to ApJ
Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
Creators: name: Jin, Sheng
name: Mordasini, Christoph
name: Parmentier, Vivien
name: van Boekel, Roy
name: Henning, Thomas
name: Ji, Jianghui
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We apply hydrodynamic evaporation models to different synthetic planet populations that were obtained from a planet formation code based on a core-accretion paradigm. We investigated the evolution of the planet populations using several evaporation models, which are distinguished by the driving force of the escape flow (X-ray or EUV), the heating efficiency in energy-limited evaporation regimes, or both. Although the mass distribution of the planet populations is barely affected by evaporation, the radius distribution clearly shows a break at approximately 2 $R_{\oplus}$. We find that evaporation can lead to a bimodal distribution of planetary sizes (Owen & Wu 2013) and to an "evaporation valley" running diagonally downwards in the orbital distance - planetary radius plane, separating bare cores from low-mass planet that have kept some primordial H/He. Furthermore, this bimodal distribution is related to the initial characteristics of the planetary populations because low-mass planetary cores can only accrete small primordial H/He envelopes and their envelope masses are proportional to their core masses. We also find that the population-wide effect of evaporation is not sensitive to the heating efficiency of energy-limited description. However, in two extreme cases, namely without evaporation or with a 100\% heating efficiency in an evaporation model, the final size distributions show significant differences; these two scenarios can be ruled out from the size distribution of $Kepler$ candidates.
description: Accepted for publication in ApJ; 24 pages, 16 figures
Intersubband polaritonic metasurfaces for flat nonlinear optics
Creators: name: Nookala, Nishant
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: Metasurfaces
Nonlinear optics
Intersubband transitions

description: Much attention has been drawn in recent years towards the creation of two-dimensional equivalents of traditionally three-dimensional optical elements. The reduction in dimensionality offers advantages such as a smaller spatial footprint, reduced manufacturing and operating complexity, and access to more exotic optical functionalities than can be achieved in a traditional bulk optics approach. Metasurface-based flat optical components, comprised of arrays of subwavelength-spaced scatterers, have emerged as a promising candidate for the realization of this vision, but have been largely constrained to the domain of linear interactions of light with matter. Nonlinear effects are intrinsically weak in bulk materials, and even more so across subwavelength volumes, meaning realization of practical and efficient nonlinear optical metasurfaces has generally been out of reach. In this thesis, a series of metasurface designs are proposed and experimentally verified to exhibit record setting nonlinearities across deeply subwavelength volumes. The metasurfaces are comprised of metallic nanoantennas patterned onto multiple-quantum well structures possessing tailored intersubband electronic resonances. We term the ensemble structure an Intersubband Polaritonic Metasurface (IPM), owing to the nature of the coupling of the electromagnetic antenna mode with the electronic intersubband transition. Suitable design of the antenna geometry allows one to access and enhance the giant intrinsic nonlinearity of intersubband transitions, which are subject to polarization-selection rules that typically inhibit their operation configuration. Further, due to their subwavelength thickness, IPMs are not constrained to the typical phase-matching considerations of bulk nonlinear optics. In the first part of this study, we investigate IPMs for efficient second-harmonic generation. A novel architecture consisting of etched nanoantenna volumes is proposed and experimentally demonstrated to exhibit a record setting second-order nonlinearity in the mid-infrared spectral range. Using this design, we experimentally demonstrate a means to control the phase of the generated nonlinear signal via the Pancharatnam-Berry geometric phase approach. We then present and demonstrate a simplified fabrication procedure for the creation of efficient IPMs, forgoing the rather cumbersome wafer-bonding and substrate removal process inherent to earlier designs. Finally, we propose and verify a metasurface design exhibiting an ultrafast third-order nonlinearity
Dalla D.I.A. alla S.C.I.A.: nuovi percorsi dei rapporti tra pubblica amministrazione e cittadino
Creators: name: Saltelli, Serena
Publisher: name: Universita degli studi di Salerno
Year: 2013
Subjects: subject: IUS/17 DIRITTO PENALE
subject: Segnalazione certificata di inizio attività

description: 2011 - 2012
description: The troubled history of article 19 of Law 7th August 1990, n. 241 provides the undisputable proof of how impossible is to shape the relationship between Public Administration and Private Sector merely relying on the opposition between authority and freedom and on the required and fundamental supremacy of the former over the latter due to the sacrifice of the private interests over the common and general interest. The transformation of the relationship between public administration and Private Sector has involved the meaningful shift of the administrative function from an "active" power (commanding) to a power of control (ruling first and monitoring after) of the citizen's actions, whose statements are directly linked with administrative effects without the strict need for an official formal act from the Public. [edited by Author]
title: Technical Matter Wave Optics - Imaging devices for Bose condensed matter waves - an aberration analysis in space and time
Creators: name: Teske, Jan
Publisher: name: UNSPECIFIED
Year: 2023

description: Cold atomic gases are the ultimate quantum sensors. Embedded in a matter-wave interferometer, they provide a platform for high-precision sensing of accelerations and rotations probing fundamental physical questions. As in all optical instruments, these devices require careful modeling. Sources of possible aberrations need to be quantified and optimized to guarantee the best possible performance. This applies in particular to high-demanding experiments in microgravity with low repetition rates. In this thesis, we present a theoretical (3+1)d aberration analysis of expanded Bose-Einstein condensates. We demonstrate that the Bogoliubov modes of the scaled mean-field equation serve as good basis states to obtain the corresponding aberration coefficients. Introducing the Stringari polynomials, we describe density and phase variations in terms of a multipole decomposition analogous to the Zernike wavefront analysis in classical optics. We apply our aberration analysis to Bose-Einstein condensates on magnetic chip traps. We obtain the trapping potential using magnetic field simulations with finite wire elements. Using the multipole expansion, we characterize the anharmonic contributions of the Ioffe-Pritchard type Zeeman potential. Used as a matter-wave lens for delta-kick collimation, we determine the wavefront aberrations in terms of \say{Seidel-diagrams}. Supported by (3+1)d Gross-Pitaevskii simulations we study mean-field interactions during long expansion times. Matter-wave interferometry with Bose-Einstein condensates can also be performed in guiding potentials. One of the building blocks are toroidal condensates in a ring-shaped geometry. The required light field patterns are obtained by using the effect of conical refraction or with programmable digital micromirror devices. For the former, we study equilibrium properties and compare them with experimental data. We investigate the collective excitations in the two-dimensional ring-shaped condensate. Our result is compared to the numerical results of the Bogoliubov-de Gennes equations. The latter is used to find signatures in the excitation spectrum during the topological transition from simply connected harmonic to multiply connected ring traps. Changing the topology dynamically leads to radial excitations of the condensate. We propose a damping mechanism based on feedback measurements to control the motion within the toroidal ring.
Anomalous Second Harmonic Generation from Atomically Thin MnBi2Te4
Creators: name: Fonseca, Jordan
name: Diederich, Geoffrey M.
name: Ovchinnikov, Dmitry
name: Cai, Jiaqi
name: Wang, Chong
name: Yan, Jiaqiang
name: Xiao, Di
name: Xu, Xiaodong
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: MnBi2Te4 is a van der Waals topological insulator with intrinsic intralayer ferromagnetic exchange and A-type antiferromagnetic interlayer coupling. Theoretically, it belongs to a class of structurally centrosymmetric crystals whose layered antiferromagnetic order breaks inversion symmetry for even layer numbers, making optical second harmonic generation (SHG) an ideal probe of the coupling between the crystal and magnetic structures. Here, we perform magnetic field and temperature-dependent SHG measurements on MnBi2Te4 flakes ranging from bulk to monolayer thickness. We find that the dominant SHG signal from MnBi2Te4 is unexpectedly unrelated to both magnetic state and layer number. We suggest that surface SHG is the likely source of the observed strong SHG, whose symmetry matches that of the MnBi2Te4-vacuum interface. Our results highlight the importance of considering the surface contribution to inversion symmetry-breaking in van der Waals centrosymmetric magnets.
MC^2: Constraining the Dark Matter Distribution of the Violent Merging Galaxy Cluster CIZA J2242.8+5301 by Piercing through the Milky Way
Creators: name: Jee, M. James
name: Stroe, Andra
name: Dawson, William
name: Wittman, David
name: Hoekstra, Henk
name: Bruggen, Marcus
name: Rottggering, Huub
name: Sobral, David
name: van Weeren, Reinout J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: CIZA J2242.8+5301 is a merging system with a prominent (~2 Mpc long) radio relic, which together with the morphology of the X-ray emission provides strong evidence for a violent collision along the N-S axis. We present our constraints on the dark matter distribution of this unusual system using Subaru and CFHT imaging data. Measuring a high S/N lensing signal from this cluster is potentially a challenging task because of its proximity to the Milky Way plane (|b|~5 deg). We overcome this challenge with careful observation planning and systematics control, which enables us to successfully map the dark matter distribution of the cluster with high fidelity. The resulting mass map shows that the mass distribution is highly elongated along the N-S merger axis inferred from the orientation of the radio relics. Based on our mass reconstruction, we identify two sub-clusters, which coincide with the cluster galaxy distributions. We determine their masses using MCMC analysis by simultaneously fitting two NFW halos without fixing their centroids. The resulting masses of the northern and southern systems are $M_{200}=11.0_{-3.2}^{+3.7}\times10^{14} M_{\sun}$ and $9.8_{-2.5}^{+3.8}\times10^{14} M_{\sun}$, respectively, indicating that we are witnessing a post-collision of two giant systems of nearly equal mass. When the mass and galaxy centroids are compared in detail, we detect ~ 1' (~190 kpc) offsets in both northern and southern sub-clusters. We find that the galaxy luminosity-mass offset for the northern clump is statistically significant at the ~2 sigma level whereas the detection is only marginal for the southern sub-cluster in part because of a relatively large mass centroid error. We conclude that it is yet premature to uniquely attribute the galaxy-mass misalignment to SIDM and discuss caveats.
description: submitted to ApJ
Statistical characterization of turbulence intermittency in SOL-like regimes in the Helimak
Creators: name: Taylor, Edward I.
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: Turbulence
Intermittency
Nuclear fusion
Tokamaks
Scrape-off layer
Blobs
Filaments
Plasma

description: Plasma turbulence intermittency is investigated in the Texas Helimak, a simple magnetic torus which is a physical approximation to the sheared cylindrical slab. The statistical properties of the intermittency are examined through a conditional analysis of probe signal bursts and the existence of so called "blobs", coherent plasma objects which transport large amounts of particles and heat, is explored. It is shown that the conditional analysis most likely extracts artifacts due to the finite ensemble size and that no coherent part of the bursts is detected throughout the Helimak radii for all the externally applied biases. The probe signal bursts rarely follow Poisson statistics, and a match with a recently developed stochastic model based upon this is more than likely due to the large number of parameters.
title: Personal naming practices in early modern Scotland: a comparative study of eleven parishes, 1680-1839
Creators: name: Crook, Alice Louise
Publisher: name: University of Glasgow
Year: 2016
Subjects: subject: Early modern Scotland, personal names, naming practices, naming patterns.

description: This thesis investigates name giving in early modern Scotland through the collection and analysis of a corpus of 63,460 baptismal records from the Old Parish Registers of eleven parishes between 1680 and 1839. Some use is also made of marital and burial records. Parishes were chosen to represent a range of geographical, linguistic, and social variables, and comprise Auchtermuchty, Dundonald, Durness, Govan, Holm, Kilmallie, Kilrenny, Longside, Saltoun, Tiree, and Tongland.
While large collections of first names from both mediaeval and modern Scotland have recently been made available, a dataset of early modern names has not previously been produced. The lack of such data and subsequent lack of analysis are particularly important to redress due to both the political and social upheaval in Scotland during this time, and the development of naming systems in contemporary Europe. This thesis therefore contributes both a dataset of early modern names and preliminary analysis of these names, allowing Scotland to be situated within the wider European context.
The principal methodology is quantitative. By this means, the study establishes and compares the name-stock in the different parishes. It also investigates sources of names, such as first names derived from surnames, and female names derived from male names, and highlights regional and other patterns.
Naming motivations are investigated through close analysis of name-sharing. Records for 16,426 families are used to establish the incidence of name-sharing with parents, maternal and paternal grandparents, deceased elder siblings, other relatives, and non-relatives such as godparents, landowners, and ministers. Birth order and unusual names are used to investigate the likelihood of name-sharing being deliberate. Rates of name-sharing are also used to demonstrate the varying incidence of conformity to the so-called Scottish ‘traditional’ naming pattern (naming after relatives in fixed sequence). For all naming practices, regional differences between these geographically disparate communities are examined, with particular focus on the Highland/Lowland divide.
Although the thesis focuses primarily on first names, middle names are also examined, in terms of the name-stock, the influences behind naming, and the upward trend of this emerging practice throughout the period studied. The research establishes the primacy of mothers’ maiden names in this position, and also investigates the incidence of other types of commemorative middle names.
In addition to quantitative analysis, complementary qualitative analysis of 12 case studies is presented. Each case study comprises one extended familial group, making it possible to explore in greater detail how various naming practices were used within individual families.
The convergent evolution of mammalian reliance on a 'keystone vegetation structure' in Madagascar and Australia
Creators: name: Romanello, Domenic Michael
name: 0000-0001-8353-0020
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: Tree hollows
Lemurs
Marsupials

description: Tree hollow inhabitance is a trait that has evolved multiple times over the course of mammalian evolution, but the selective pressures for this trait are not well-understood, especially in the tropics. In Australia, there are 35 species of tree hollow-inhabiting marsupials (75% of the continent’s arboreal marsupials). The adaptive radiation of Australian tree hollow inhabiting mammals is hypothesized to have been driven by thermoregulatory demands and constrained by tree hollow abundance and body size. Because Australia exhibits disparate temperature extremes and the highest tree hollow abundance globally, the continent can support a high diversity of tree hollow inhabiting species. However, tree hollow inhabitance has not been investigated similarly in the tropics, and there is a paucity of data on tree hollow abundance in low-latitude forests. My investigation of tree hollow inhabitance in Madagascar identified 36 species of tree hollow-inhabiting lemurs, comparable to the mammalian tree hollow inhabitant species richness of Australia. I hypothesized that tree hollow inhabitance within Madagascar was driven by thermoregulatory demands and constrained by tree hollow abundance and body size. I tested this hypothesis by comparing the selective pressures and constraints acting on lemuriform tree hollow inhabitants, lemuriform non-tree hollow inhabitants, and tree hollow inhabitant marsupials in Australia. Because data on tree hollow abundance are lacking in Madagascar, I used a proxy for tree hollow abundance: mean yearly rainfall, which positively correlates with global tree hollow abundance. Within Madagascar, tree hollow inhabitant sites did not differ in thermoregulatory demands or tree hollow abundance, but non-tree hollow inhabiting lemuriformes were significantly larger than tree hollow inhabiting lemuriformes. Furthermore, tree hollow inhabitant sites in Madagascar had significantly higher rainfall levels (suggesting high tree hollow abundance) than Australian tree hollow inhabitant sites, but Australian tree hollow inhabitant sites had significantly higher temperature variability (suggesting higher thermoregulatory demands) than tree hollow inhabitant sites in Madagascar. Therefore, the species richness of mammalian tree hollow inhabitants in both regions may be due to different selective pressures. Because nearly 80% of tree hollow inhabiting lemuriformes are critically endangered, endangered, or vulnerable, understanding the selective pressures and constraints for inhabitance of this keystone vegetation structure is critical to conserving tree hollow inhabitant species threatened with extinction.
Identifying climatic drivers of hybridization with a new ancestral niche reconstruction method
Creators: name: Folk, Ryan A.
name: Gaynor, Michelle L.
name: Engle-Wrye, Nicholas J.
name: O'Meara, Brian C.
name: Soltis, Pamela S.
name: Soltis, Douglas E.
name: Guralnick, Robert P.
name: Smith, Stephen A.
name: Grady, Charles J.
name: Okuyama, Yudai
Publisher: name: Zenodo
Year: 2024
Subjects: subject: ancestral niche reconstruction
subject: Hybridization
subject: Pleistocene
subject: paleoclimate
subject: Genetics
subject: FOS: Biological sciences
subject: Ecology, Evolution, Behavior and Systematics

description: Applications of molecular phylogenetic approaches have uncovered evidence of hybridization across numerous clades of life, yet the environmental factors responsible for driving opportunities for hybridization remain obscure. Verbal models implicating geographic range shifts that brought species together during the Pleistocene have often been invoked, but quantitative tests using paleoclimatic data are needed to validate these models. Here, we produce a phylogeny for Heuchereae, a clade of 15 genera and 83 species in Saxifragaceae, with complete sampling of recognized species, using 277 nuclear loci and nearly complete chloroplast genomes. We then employ an improved framework with a coalescent simulation approach to test and confirm previous hybridization hypotheses and identify one new intergeneric hybridization event. Focusing on the North American distribution of Heuchereae, we introduce and implement a newly developed approach to reconstruct potential past distributions for ancestral lineages across all species in the clade and across a paleoclimatic record extending from the late Pliocene. Time calibration based on both nuclear and chloroplast trees recovers a mid- to late-Pleistocene date for most inferred hybridization events, a timeframe concomitant with repeated geographic range restriction into overlapping refugia. Our results indicate an important role for past episodes of climate change, and the contrasting responses of species with differing ecological strategies, in generating novel patterns of range contact among plant communities and therefore new opportunities for hybridization. The new ancestral niche method flexibly models the shape of niche while incorporating diverse sources of uncertainty and will be an important addition to the current comparative methods toolkit.
description: Standard phylogenetic tree, alignment, and GIS software such as QGIS.
Funding provided by: National Science FoundationCrossref Funder Registry ID: https://ror.org/021nxhr62Award Number: DBI-1523667
Funding provided by: iDigBioAward Number: DBI-1547229
Funding provided by: iDigBioAward Number: DGE-1842473
description: Published here are the complete Supplements as a collated document, phylogenies, gene trees, alignments, and paleoclimatic interpolations.
Pre-LHB Evolution of the Earth's Obliquity
Creators: name: Li, Gongjie
name: Batygin, Konstantin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The Earth's obliquity is stabilized by the Moon, which facilitates a rapid precession of the Earth's spin-axis, de-tuning the system away from resonance with orbital modulation. It is however, likely that the architecture of the Solar System underwent a dynamical instability-driven transformation, where the primordial configuration was more compact. Hence, the characteristic frequencies associated with orbital perturbations were likely faster in the past, potentially allowing for secular resonant encounters. In this work we examine if at any point in the Earth's evolutionary history, the obliquity varied significantly. Our calculations suggest that even though the orbital perturbations were different, the system nevertheless avoided resonant encounters throughout its evolution. This indicates that the Earth obtained its current obliquity during the formation of the Moon.
description: 5 pages, 3 figures. Accepted for publication to ApJ
Symmetry Breaking in an Extended-O(2) Model
Creators: name: Hostetler, Leon
name: Sakai, Ryo
name: Zhang, Jin
name: Unmuth-Yockey, Judah
name: Bazavov, Alexei
name: Meurice, Yannick
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Motivated by attempts to quantum simulate lattice models with continuous Abelian symmetries using discrete approximations, we consider an extended-O(2) model that differs from the ordinary O(2) model by an explicit symmetry breaking term. Its coupling allows to smoothly interpolate between the O(2) model (zero coupling) and a $q$-state clock model (infinite coupling). In the latter case, a $q$-state clock model can also be defined for non-integer values of $q$. Thus, such a limit can also be considered as an analytic continuation of an ordinary $q$-state clock model to non-integer $q$. The phase diagram of the extended-O(2) model in the infinite coupling limit was established in our previous work, where it was shown that for non-integer $q$, there is a second-order phase transition at low temperature and a crossover at high temperature. In this work, we investigate the model at finite values of the coupling using Monte Carlo and tensor methods. The results may be relevant for configurable Rydberg-atom arrays.
description: 7 pages, 4 Figures; Talk given at the 39th International Symposium on Lattice Field theory (LATTICE2022) in Bonn, Germany; August 8-13 2022
title: Tra Sagres e Lisbona: progetti museali e identità nazionale nell’Estado Novo portoghese
title: Between Sagres and Lisbon: museum projects and national identity in the Portuguese Estado
titleType: AlternativeTitle
Creators: name: Gori, Annarita
Publisher: name: A. Gori, Tra Sagres e Lisbona: progetti museali e identità nazionale nell’Estado Novo portoghese, «Memoria e Ricerca», 54, 2017, pp. 61-79
Year: 2017

description: The Portuguese national identity is closely linked to the deeds of the Age of Discovery. During the long period of the Estado Novo (1933-1974) the regime extensively resorted to the myth of descobridores to legitimize itself, build consensus and self-represent. One of the most interesting examples in this regard is the monument and the museum dedicated to Henry the Navigator on the Sagres promontory. The regime launched three contests - in 1933, 1936 and 1954 - but all were resolved in stalemate. This article aims to analyze the different solutions presented in the three contests, taking into consideration the museum as a socio-political institution that, through collections and exhibitions, conveyed myths and value and tried to build a shared national identity. Furthermore the long-term approach allowed for the investigation of difficulties in representing the National past in relation to political and social vicissitudes, both nationally and internationally, and the consequent change in the museum setting over a period of almost thirty years.
Coupled atmospheric, hydrodynamic, and hydrologic models for simulation of complex phenomena
Creators: name: Choudhary, Gajanan Krishna
name: 0000-0003-0826-8493
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: 2D-3D coupling
Strong and weak coupling
Shallow water equations
Diffusive wave equations
Primitive equations
Wetting and drying
Baroclinic flow
Compound flooding

description: Simulating the interplay between atmospheric, ocean, and overland physics is often too complicated for any single model to handle due to limitations on developmental and computational costs. A variety of models that specialize in specific physics exist, such as 2D and 3D shallow water and transport models in ADvanced CIRCulation (ADCIRC) and Adaptive Hydraulics (AdH) for ocean and estuarine dynamics, Gridded Surface Subsurface Hydrologic Analysis (GSSHA) and Hydrologic Engineering Center's (HEC) River Analysis System (HEC-RAS) for 2D/1D overland flow, and Global Forecast System (GFS) and North American Mesoscale Forecast System (NAM) for atmospheric physics. This dissertation explores strong and weak coupling between different models to simulate complex phenomena that they cannot individually handle. One-way weak coupling from atmospheric models to ocean or overland flow models is already ubiquitous in the form of usage of meteorological forcing on the flow models. Coupling between 2D and 3D shallow water models including baroclinic transport, and between shallow water and overland flow models remain relatively unexplored. Strong coupling between 2D and 3D shallow water and baroclinic transport models is the major focus of this work. On studying multiple verification and validation cases, and applications testing the limits of 2D-3D coupling, it is concluded that strongly coupled 2D and 3D shallow water and transport models are conservative, stable, accurate, and convergent in line with theory, and are able to simulate physics that solely 2D or 3D models cannot in general. They also enable building computationally cheaper 3D models by enabling replacement of non-critical 3D regions with 2D subdomains. The second focus of this work is weak one/two-way coupling between 2D shallow water and 2D/1D overland flow models, which are in turn driven by one-way coupling from an atmospheric model. Two-way coupled models are shown to be conservative and capable of simulating compound flooding effects. An application of the coupled models to simulate flooding in Houston, Texas, due to Hurricane Harvey of August 2017 is presented, the results of which demonstrate the suitability of the models for use in high-fidelity forecasts of flooding during hurricanes, after some improvements.
Determinantal Point Process Priors for Bayesian Variable Selection in Linear Regression
Creators: name: Kojima, Mutsuki
name: Komaki, Fumiyasu
Publisher: name: arXiv
Year: 2014
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: We propose discrete determinantal point processes (DPPs) for priors on the model parameter in Bayesian variable selection. By our variable selection method, collinear predictors are less likely to be selected simultaneously because of the repulsion property of discrete DPPs. Three types of DPP priors are proposed. We show the efficiency of the proposed priors through numerical experiments and applications to collinear datasets.
Discovery of interstellar NC4NH+: dicyanopolyynes are indeed abundant in space
Creators: name: Agundez, M.
name: Cabezas, C.
name: Marcelino, N.
name: Fuentetaja, R.
name: Tercero, B.
name: de Vicente, P.
name: Cernicharo, J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The previous detection of two species related to the non polar molecule cyanogen (NCCN), its protonated form (NCCNH+) and one metastable isomer (CNCN), in cold dense clouds supported the hypothesis that dicyanopolyynes are abundant in space. Here we report the first identification in space of NC4NH+, which is the protonated form of NC4N, the second member of the series of dicyanopolyynes after NCCN. The detection was based on the observation of six harmonically related lines within the Yebes 40m line survey of TMC-1 QUIJOTE. The six lines can be fitted to a rotational constant B = 1293.90840 +/- 0.00060 MHz and a centrifugal distortion constant D = 28.59 +/- 1.21 Hz. We confidently assign this series of lines to NC4NH+ based on high-level ab initio calculations, which supports the previous identification of HC5NH+ by Marcelino et al. (2020) from the observation of a series of lines with a rotational constant 2 MHz lower than that derived here. The column density of NC4NH+ in TMC-1 is (1.1 +1.4 -0.6)e10 cm-2, which implies that NC4NH+ is eight times less abundant than NCCNH+. The species CNCN, previously reported toward L483 and tentatively in TMC-1, is confirmed in this latter source. We estimate that NCCN and NC4N are present in TMC-1 with abundances a few times to one order of magnitude lower than HC3N and HC5N, respectively. This means that dicyanopolyynes NC-(CC)n-CN are present at a lower level than the corresponding monocyanopolyynes HCC-(CC)n-CN. The reactions of the radicals CN and C3N with HNC arise as the most likely formation pathways to NCCN and NC4N in cold dense clouds.
description: Accepted for publication in A&A Letters
Lessons from supersymmetry: "Instead-of-Confinement" Mechanism
Creators: name: Shifman, M.
name: Yung, A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We review physical scenarios in different vacua of N=2 supersymmetric QCD deformed by the mass term μfor the adjoint matter. This deformation breaks supersymmetry down to N=1 and, at large μ, the theory flows to N=1 SQCD. We focus on dynamical scenarios which can serve as prototypes of what we observe in real-world QCD. The so-called r=N vacuum is especially promising in this perspective. In this vacuum an "instead-of-confinement" phase was identified previously, which is qualitatively close to the conventional QCD confinement: the quarks and gauge bosons screened at weak coupling, at strong coupling evolve into monopole-antimonopole pairs confined by non-Abelian strings. We review genesis of this picture.
description: To be published in {\sl Quarks 50}, Murray Gell-Mann Festschrift, (World Scientific, Singapore, 2015). 20 pp., 3 figs
En etapas : parenting practices and resiliency of mothers migrating with children from Central America’s Northern Triangle
Creators: name: Gonzalez, Dora Idalia
name: 0000-0002-9668-3146
Publisher: name: The University of Texas at Austin
Year: 2019
Subjects: Trauma
Migration
Central America
Migrating mothers
Migrant mothers
Asylum-seeking mothers
Migrant children
Migrating with children
Migrating families
Migration process
Migrant trauma
Migration trauma

description: In this project, I explored the ways asylum-seeking mothers from Central America’s Northern Triangle who migrated with children to the U.S. navigated their parental role during the migration process. Specifically, I considered the resilience and coping strategies mothers employed during difficult experiences, transitions, and parenting dilemmas. Employing a qualitative research design and hybrid grounded theory/template approach, I interviewed 10 asylum-seeking mothers in Austin. Upon analyzing my data, I discovered a variety of themes and grouped them into three core categories: 1) experiencing hardship and loss in the context of precarious migration and/or past traumas, 2) building resilience and strength, and 3) navigating parental responsibilities and dilemmas. From my findings, I developed working model of building resilience and strength (RS) that is comprised of eight conceptual codes: 1) faith, church and religion, 2) resettlement assistance and/or community programs, 3) determination and agency, 4) family and community closeness, 5) children as meaning and purpose, 6) opportunities for children, 7) appreciation for safety and access to resources and services, 8) hope for a better life and future; rebuild and survive. My data also shows how context affects parenting decisions. Mothers discussed issues related to socialization, communication, family separation, and transnational parenting. Based on my findings, I posit that the RS working model helps build resilience frameworks that are theoretically and practically useful with vulnerable populations, and I make specific recommendations toward social work practice concerning parenting
title: Die Virtuelle Klemmleiste – ein Ansatz zur Integration der Verhaltenslogik in den Digitalen Zwilling
Creators: name: Kutscher, Vladimir
Publisher: name: UNSPECIFIED
Year: 2023

description: Die Vision eines Digitalen Zwillings beschreibt ein durchgängiges Abbild eines Systems, welches in diversen Anwendungsfällen als virtuelle Repräsentation eingesetzt werden kann und in einer bidirektionalen Verbindung mit dem Physischen Zwilling steht. Der Digitale Zwilling soll dabei Eigenschaften der Physischen Zwillings abbilden. Zu den wesentlichen Eigenschaften eines mechatronischen bzw. Cyber-Physischen Systems gehört auch das inhärente Verhalten, welches auf der individuellen Verhaltenslogik des Systems basiert. Die Verhaltenslogik wird durch die eingebettete Software und Elektronik implementiert. Die Integration der originalgetreuen Verhaltenslogik, welche aus der Elektronik und der eingebetteten Software des Physischen Zwillings hervorgeht, ist wissenschaftlich bisher nicht durchdrungen. Aus dieser Forschungslücke leitet sich die Zielsetzung der Dissertation ab. Das Ziel der Dissertation ist die Integration der Verhaltenslogik in den Digitalen Zwilling. Im Fokus liegt dabei die Nutzung der originalen eingebetteten Software, die mittels einer virtuellen Abbildung der Elektronik zum direkten Einsatz im Digitalen Zwilling befähigt wird. Zur Erreichung des Ziels erfolgt im Kern der Dissertation die Entwicklung eines Konzepts einer Virtuellen Klemmleiste, welche die Verbindung zwischen der virtuellen Verhaltenslogik und den anschließenden Partialmodellen des Digitalen Zwillings herstellt und dadurch die Integration des Verhaltens in den Digitalen Zwilling ermöglicht. Der zugehörige Prozess der Integration der Verhaltenslogik in den Digitalen Zwilling besteht aus den zwei Teilprozessen der Virtualisierung der Verhaltenslogik und der Erweiterung eines Digitalen Zwillings durch virtualisierte Verhaltenslogik. Zur Validierung der Tragfähigkeit des Konzepts wird der Prozess am Beispiel eines CNC (Computerized Numerical Control) Laserplotters durchgeführt und implementiert. Die Validierung zeigt, dass das entwickelte Konzept geeignet ist, um das originalgetreue Verhalten in den Digitalen Zwilling zu integrieren.
Genetic Algorithm in Audio Steganography
Creators: name: Rana, Manisha
name: Tanwar, Rohit
Publisher: name: arXiv
Year: 2014
Subjects: subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: With the advancement of communication technology,data is exchanged digitally over the network. At the other side the technology is also proven as a tool for unauthorized access to attackers. Thus the security of data to be transmitted digitally should get prime focus. Data hiding is the common approach to secure data. In steganography technique, the existence of data is concealed. GA is an emerging component of AI to provide suboptimal solutions. In this paper the use of GA in Steganography is explored to find future scope of research.
description: 6 pages,2 figures Published with International Journal of Engineering Trends and Technology (IJETT). arXiv admin note: text overlap with arXiv:1003.4084, arXiv:1205.2800 by other authors without attribution
A Uniform History for Galaxy Evolution
Creators: name: Steinhardt, Charles L.
name: Speagle, Josh S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Recent observations indicate a remarkable similarity in the properties of evolving galaxies at fixed mass and redshift, prompting us to consider the possibility that most galaxies may evolve with a common history encompassing star formation, quasar accretion, and eventual quiescence. We quantify this by defining a "synchronization timescale" for galaxies as a function of mass and redshift that characterizes the extent to which different galaxies of a common mass are evolving in the same manner at various cosmic epochs. We measure this synchronization timescale using 9 different star-forming galaxy observations from the literature and SDSS quasar observations spanning $0 < z \lesssim 6$. Surprisingly, this synchronization timescale is a constant, approximately 1.5 Gyr for all combinations of mass and time. We also find that the ratio between the stellar mass of galaxies turning off star formation and black hole mass of turnoff quasars is approximately 30:1, much lower than the 500:1 for quiescent galaxies at low redshift. As a result, we propose a model in which the star-forming "main sequence", analogous quasar behavior, and other observations form a galactic evolution "main sequence", in which star formation occurs earliest, followed by supermassive black hole accretion, and feedback between the two are dominated by deterministic rather than stochastic processes.
description: ApJ, in press