cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Evolution of the Loop-Top Source of Solar Flares--Heating and Cooling Processes
Creators: name: Jiang, Yan Wei
name: Liu, Siming
name: Liu, Wei
name: Petrosian, Vahe
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a study of the spatial and spectral evolution of the loop-top (LT) sources in a sample of 6 flares near the solar limb observed by {\it RHESSI}. A distinct coronal source, which we identify as the LT source, was seen in each of these flares from the early ``pre-heating'' phase through the late decay phase. Spectral analyses reveal an evident steep power-law component in the pre-heating and impulsive phases, suggesting that the particle acceleration starts upon the onset of the flares. In the late decay phase the LT source has a thermal spectrum and appears to be confined within a small region near the top of the flare loop, and does not spread throughout the loop, as is observed at lower energies. The total energy of this source decreases usually faster than expected from the radiative cooling but much slower than that due to the classical Spitzer conductive cooling along the flare loop. These results indicate the presence of a distinct LT region, where the thermal conductivity is suppressed significantly and/or there is a continuous energy input. We suggest that plasma wave turbulence could play important roles in both heating the plasma and suppressing the conduction during the decay phase of solar flares. With a simple quasi-steady loop model we show that the energy input in the gradual phase can be comparable to that in the impulsive phase and demonstrate how the observed cooling and confinement of the LT source can be used to constrain the wave-particle interaction.
description: 32 pages, 14 figures, submitted to ApJ
[Photographs from Kawaiisu fieldwork]
Creators: name: Klein, Carol
name: Klein, Sheldon
name: Peebles, Carmen
name: Peebles, George
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2015
Subjects: subject: xaw
subject: Kawaiisu language

description: Prints of two scanned originals. One page with a picture of a basket (front and back of original print on one sheet). One 3x5 picture of George and Carmen Peebles standing outside a cave in 1982.
Implicit Graph Neural Networks
Creators: name: Gu, Fangda
name: Chang, Heng
name: Zhu, Wenwu
name: Sojoudi, Somayeh
name: Ghaoui, Laurent El
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Graph Neural Networks (GNNs) are widely used deep learning models that learn meaningful representations from graph-structured data. Due to the finite nature of the underlying recurrent structure, current GNN methods may struggle to capture long-range dependencies in underlying graphs. To overcome this difficulty, we propose a graph learning framework, called Implicit Graph Neural Networks (IGNN), where predictions are based on the solution of a fixed-point equilibrium equation involving implicitly defined "state" vectors. We use the Perron-Frobenius theory to derive sufficient conditions that ensure well-posedness of the framework. Leveraging implicit differentiation, we derive a tractable projected gradient descent method to train the framework. Experiments on a comprehensive range of tasks show that IGNNs consistently capture long-range dependencies and outperform the state-of-the-art GNN models.
description: Accepted by NeurIPS 2020 at: https://papers.nips.cc/paper/2020/hash/8b5c8441a8ff8e151b191c53c1842a38-Abstract.html
DAIRY FARM SIZE, ENTRY, AND EXIT IN A DECLINING PRODUCTION REGION
Creators: name: Rahelizatovo, Noro C.
name: Gillespie, Jeffrey M.
name: Rahelizatovo, Noro C.
name: Gillespie, Jeffrey M.
Publisher: name: Unknown
Year: 1999
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: dairy farms
subject: Markov chain analysis
subject: seemingly unrelated regression

description: As with most agricultural industries, the U.S. dairy industry has evolved into a structure including fewer yet larger firms. In Louisiana, total milk production has declined along with dairy farm numbers since 1972. This study addresses the impact of alternative policies, macroeconomic factors, and technology on the structure of the Louisiana dairy industry using a micro-data non-stationary Markov chain analysis. Results indicate that a number of factors have affected the structure of the industry in Louisiana, including but not limited to prices, milk supply reduction programs, technology and interest rates.
Bjorken variable and scale dependence of quark transport coefficient in Drell-Yan process for proton incident on nucleus
Creators: name: Bai, Tian-Xing
name: Duan, Chun-Gui
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Drell-Yan process for proton incident on nuclei is an excellent place for deeply studying the parton propagation in a nucleus. By means of the nuclear parton distributions determined only with lepton-nuclear deep inelastic scattering experimental data and the analytic parameterization of quenching weight based on BDMPS formalism, a phenomenological analysis of the nuclear Drell-Yan differential cross section ratio as a function of Feynman variable is performed from Fermilab E906 and E866 experimental data. With the nuclear geometry effect on nuclear Drell-Yan process and the quark transport coefficient as a constant, our predictions are in good agreement with the experimental measurements. It is found that nuclear geometry effect has a significant impact on the quark transport coefficient in cold nuclear matter. It is necessary to consider the detailed nuclear geometry in studying the nuclear Drell-Yan process. Our calculated results reveal that the difference in the values of quark transport coefficient exists from E906 and E866 experiments. However, confirming the conclusion that the quark transport coefficient depends on the target-quark momentum fraction, still need more accurate experimental data on the Drell-Yan differential cross section ratio in the future. Three models are proposed and discussed for the quark transport coefficient as a function of the measurable kinematic variables. The quark transport coefficient $\hat{q}$ is determined as a function of the Bjorken variable $x_2$ and scale $Q^2$. It is hoped that the parametrization form of quark transport coefficient in the cold nuclear medium can help to think about the parton propagation mechanism in nuclear matter.
description: arXiv admin note: text overlap with arXiv:2011.14350
Viscosity and mutual diffusion in strongly asymmetric binary ionic mixtures
Creators: name: Bastea, Sorin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present molecular dynamics simulation results for the viscosity and mutual diffusion constant of a strongly asymmetric binary ionic mixture (BIM). We compare the results with available theoretical models previously tested for much smaller asymmetries. For the case of viscosity we propose a new predictive framework based on the linear mixing rule, while for mutual diffusion we discuss some consistency problems of widely used Boltzmann equation based models.
description: 10 pages, 4 figures
The Impact of Direct Reading Strategy Instruction on Student Academic Achievement
Creators: name: Bolander, Maria
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: subject: Education -- Research papers (Graduate)

description: The purpose of this study was to determine the impact of teaching select reading strategies on academic achievement of fifth grade students in the area of reading comprehension. For this quasi-experimental study, students in a fifth grade reading class were randomly assigned to a treatment group who received traditional comprehension instruction with additional reading strategy instruction, or assigned to a control group which received the traditional comprehension instruction only. A pre- and post--assessment design was used in this study. The analysis of this study suggested significant improvement in reading performance for students provided with direct instruction in reading. The promising results and other research suggest that direct reading strategy instruction can improve reading comprehension scores in fifth grade students. Implications of the results and future research are discussed within the paper.
Evolutionary graph theory derived from eco-evolutionary dynamics
Creators: name: Pattni, Karan
name: Overton, Christopher E.
name: Sharkey, Kieran J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: A biologically motivated individual-based framework for evolution in network-structured populations is developed that can accommodate eco-evolutionary dynamics. This framework is used to construct a network birth and death model. The evolutionary graph theory model, which considers evolutionary dynamics only, is derived as a special case, highlighting additional assumptions that diverge from real biological processes. This is achieved by introducing a negative ecological feedback loop that suppresses ecological dynamics by forcing births and deaths to be coupled. We also investigate how fitness, a measure of reproductive success used in evolutionary graph theory, is related to the life-history of individuals in terms of their birth and death rates. In simple networks, these ecologically motivated dynamics are used to provide new insight into the spread of adaptive mutations, both with and without clonal interference. For example, the star network, which is known to be an amplifier of selection in evolutionary graph theory, can inhibit the spread of adaptive mutations when individuals can die naturally.
Self-enrichment in globular clusters. I. An analytic approach
Creators: name: Recchi, S.
name: Danziger, I. J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: By means of analytical calculations, we explore the self-enrichment scenario for Globular Cluster formation. According to this scenario, an initial burst of star formation occurs inside the core radius of the initial gaseous distribution. The outward-propagating shock wave sweeps up a shell in which gravitational instabilities may arise, leading to the formation of a second, metal-enriched, population of stars. We find a minimum mass of the proto-globular cluster of the order of 10^6 solar masses. We also find that the observed spread in the Magnitude-Metallicity relation can be explained assuming cluster-to-cluster variations of some parameters like the thermalization efficiency, the mixing efficiency and the Initial Mass Function, as well as variations of the external pressure.
description: 12 pages, 13 figures, accepted for publication in A&A
PRICE DISCOVERY IN WHEAT FUTURES MARKETS
Creators: name: Yang, Jian
name: Leatham, David J.
name: Yang, Jian
name: Leatham, David J.
Publisher: name: Unknown
Year: 1999
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: error correction model
subject: price discovery
subject: wheat futures

description: This paper examines the price discovery function for three U.S. wheat futures markets: the Chicago Board of Trade, Kansas City Board of Trade, and Minneapolis Grain Exchange. The maintained hypothesis is that futures markets search more for information than cash markets to find an equilibrium price, thus greatly improving the price discovery function. The tests reveal the existence of one equilibrium price across the three futures markets in the long run, but no cointegration among prices in the three representative cash markets.
Controls of a superconducting quantum parametron under a strong pump field
Creators: name: Masuda, Shumpei
name: Ishikawa, Toyofumi
name: Matsuzaki, Yuichiro
name: Kawabata, Shiro
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Pumped at approximately twice the natural frequency, a Josephson parametric oscillator called parametron or Kerr parametric oscillator shows self-oscillation. Quantum annealing and universal quantum computation using self-oscillating parametrons as qubits were proposed. However, controls of parametrons under the pump field are degraded by unwanted rapidly oscillating terms in the Hamiltonian, which we call non-resonant rapidly oscillating terms (NROTs) coming from the violation of the rotating wave approximation. Therefore, the pump field can be an intrinsic origin of the imperfection of controls of parametrons. Here, we theoretically study the influence of the NROTs on the accuracy of controls of a parametron: a cat-state creation and a single-qubit gate. It is shown that there is a trade-off relationship between the suppression of the nonadiabatic transitions and the validity of the rotating wave approximation in a conventional approach. We also show that the tailored time dependence of the detuning of the pump field can suppress both of the nonadiabatic transitions and the disturbance of the state of the parametron due to the NROTs.
Human [alpha]-L-iduronidase : substrate synthesis and mechanistic analysis
Creators: name: Nieman, Catharine E.
Publisher: name: University of British Columbia
Year: 2009

description: Glycosidases are enzymes responsible for hydrolysis of glycosidic bonds. On the basis of sequence sirnilarities, glycosidases have been assigned to a series of families, one of which, Family 39, contains both β-D-xylosidases and α-L-iduronidases. However, the level of sequence similarity between these two enzymes is relatively low, calling into question mechanistic conclusions made about the iduronidases on the basis of results from xylosidases. By being assigned to a family of retaining glycosidases, human α -L-iduronidase (IDUA) is also predicted to operate with net retention of anomeric configuration, and sequence alignments suggest that E299 is the catalytic nucleophile. When 4- methylumbelliferyl- α -L-idopyranosiduronic acid was incubated with IDUA in the presence of 3 M methanol, ¹H NMR analysis of the resulting products revealed the presence of methyl a-L-idopyranosiduronic acid, and a complete absence of the β -methanolysis product, thus proving IDUA to be a retaining glycosidase. In order to identify the catalytic nucleophile, 5-fluoro- α -L-idopyranosyluronic acid fluoride (5F-IdoAF) was used to label the enzyme via trapping of the intermediate. MS analysis of a peptic digest of an assay mixture containing IDUA and 5F-IdoAF permitted the identification of the labeled peptide ²⁹¹ADTPIYNDEADPLVG³⁰⁵, having m/z = 893 ± 1. Further analysis revealed that the label was attached to E299, proving it to be the catalytic nucleophile. This, together with the proof of retention of anomeric configuration, supports the assignment of IDUA to Family 39. To further probe the mechanism of this enzyme, we required a series of aryl α-Liduronides of varying reactivities. Because the glycosylation chemistry of ido compounds is poorly understood, a methodology study was performed in which five glycosylation methods were tested for their ability to form the desired anomeric stereochemistry with a range of acceptors of varying pK[sub a]. The trichloroacetimidate method was found to produce the best results, and a series of aryl α -L-iduronides was synthesized. Kinetic parameters for their hydrolysis by IDUA were determined, and it was found that both kcai and k[sub cai]/K[sub m] were independent of leaving group pK[sub a]- This indicates that either glycosylation is rate-determining, with extremely efficient proton donation at the transition state, or that some other step, such as conformational change is ratedetermining.
EDUCATIONAL PROGRAMS TO ADDRESS THE ECONOMIC ADJUSTMENTS FACING TOBACCO FARMERS AND RURAL COMMUNITIES
Creators: name: Woods, Timothy A.
name: Isaacs, Steven G.
name: Mundy, S. Darrell
name: Givan, William D.
name: Woods, Timothy A.
name: Isaacs, Steven G.
name: Mundy, S. Darrell
name: Givan, William D.
Publisher: name: Unknown
Year: 1999
Subjects: subject: Community/Rural/Urban Development
subject: educational programs
subject: tobacco producers

description: This paper discusses the context within which educational programs tailored to tobacco producers and related rural communities have developed. Discussion is expanded by examining current program approaches employed by various organizations. Many of these organizations have a manual stake in helping producers in tobacco communities develop their management capacity. A range of initiatives aimed at facilitating economic adjustment is compared, including the major issues addressed and expected outcomes. Many of the initiatives have made useful contributions; however, gaps and limitations remain. These are considered as future educational efforts and issues are discussed.
Skyrmions as quasiparticles: free energy and entropy
Creators: name: Schick, Daniel
name: Weißenhofer, Markus
name: Rózsa, Levente
name: Nowak, Ulrich
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The free energy and the entropy of magnetic skyrmions with respect to the collinear state are calculated for a (Pt$_{0.95}$Ir$_{0.05}$)/Fe bilayer on Pd(111) via atomistic spin model simulations. The simulations are carried out starting from very low temperatures where the skyrmion number is conserved up to the range where skyrmions are constantly created and destroyed by thermal fluctuations, highlighting their quasiparticle nature. The higher entropy of the skyrmions at low temperature leads to a reduced free energy, such that the skyrmions become energetically preferred over the collinear state due to entropic stabilization as predicted by linear spin-wave theory. Going beyond the linear spin-wave approximation, a sign change is shown to occur in the free energy as well as the entropy at elevated temperature.
description: 10 pages, 5 figures
The Effects of Looping on Second Graders’ Reading Achievement and Attitudes Towards School
Creators: name: Riley, Jillian
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: subject: Education -- Research papers (Graduate)

description: The purpose of this study was to examine the impact of looping on the reading achievement of second graders. The impact of looping on the attitudes towards school of these students and their parents also was assessed. The Fountas and Pinnell Benchmark System was used to collect baseline reading scores for both looping and non-looping students at the beginning of their first grade year. The same measurement was used in the third quarter of the students’ second grade year and the amount of reading growth between the looping and non-looping students was compared. Results indicated the gains in reading levels were statistically significantly larger for the students who looped compared to those who did not ( t=3.33, p
A compute-bound formulation of Galerkin model reduction for linear time-invariant dynamical systems
Creators: name: Rizzi, Francesco
name: Parish, Eric J.
name: Blonigan, Patrick J.
name: Tencer, John
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Mathematical Software (cs.MS)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: This work aims to advance computational methods for projection-based reduced order models (ROMs) of linear time-invariant (LTI) dynamical systems. For such systems, current practice relies on ROM formulations expressing the state as a rank-1 tensor (i.e., a vector), leading to computational kernels that are memory bandwidth bound and, therefore, ill-suited for scalable performance on modern many-core and hybrid computing nodes. This weakness can be particularly limiting when tackling many-query studies, where one needs to run a large number of simulations. This work introduces a reformulation, called rank-2 Galerkin, of the Galerkin ROM for LTI dynamical systems which converts the nature of the ROM problem from memory bandwidth to compute bound. We present the details of the formulation and its implementation, and demonstrate its utility through numerical experiments using, as a test case, the simulation of elastic seismic shear waves in an axisymmetric domain. We quantify and analyze performance and scaling results for varying numbers of threads and problem sizes. Finally, we present an end-to-end demonstration of using the rank-2 Galerkin ROM for a Monte Carlo sampling study. We show that the rank-2 Galerkin ROM is one order of magnitude more efficient than the rank-1 Galerkin ROM (the current practice) and about 970X more efficient than the full order model, while maintaining accuracy in both the mean and statistics of the field.
description: Revised version, 28 pages, 9 figures
The Shapley super-cluster. New X-ray detections and mass distribution
Creators: name: De Filippis, E.
name: Schindler, S.
name: Erben, T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The largest and the deepest super-structure known today is the Shapley super-cluster. This is the sky area with the highest over-density of galaxy clusters and therefore also an ideal region to test the effects of a high density environment on galaxies and on clusters. We performed an X-ray survey of a wide region surrounding the Shapley super-structure. Additionally to previously known super-cluster X-ray members, we identified diffuse X-ray emission from 35 cluster candidates without previous X-ray detection. 21 of them were previously known, optically selected super-cluster members, while the other candidates had not been previously detected in any wavelength range. Optical follow-up observations revealed that at least four of these new candidates also have optical cluster counterparts. The super-cluster shows a slightly flattened and elongated morphology. Clusters outside the central dense core are preferentially located in four perpendicular filaments in a similar way to what is seen in simulations of Large Scale Structure. We measure the cluster number density in the region to be more than one order of magnitude higher than the mean density of rich Abell clusters previously observed at similar Galactic latitudes; this over-density, in the super-cluster outskirts, is mainly due to an excess of low X-ray luminous clusters (with respect to an average population), which leads us to think that the whole region is still accreting low luminosity, small objects from the outskirts. Pushing our total X-ray mass estimate to fainter clusters would drastically increase the total super-cluster mass measure, because of the presence of the rich X-ray low luminosity population.
description: 27 pages; accepted for publication in A&A. A version of the paper with higher resolution images can be downloaded at: http://people.na.infn.it/~betty/publications_files/Shapley.ps.gz
Some remarks on $X(6900)$
Creators: name: Cao, Qin-Fang
name: Chen, Hao
name: Qi, Hong-Rong
name: Zheng, Han-Qing
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The analysis of the LHCb data on $X(6900)$ found in the di-$\jpsi$ system is performed using a momentum-dependent Flatté-like parameterization. The use of the pole counting rule and spectral density function sum rule give consistent conclusions that both confining states and molecular states are possible, or it is unable to distinguish the nature of $X(6900)$, if only the di-$\jpsi$ experimental data with current statistics are available. Nevertheless, we found that the lowest state in the di-$J/ψ$ system has very likely the same quantum numbers as $X(6900)$, and $X(6900)$ is probably not interpreted as a $J/ψ-ψ(2S)$ molecular state.
description: 4 figures
The Effect of Stereotype Threat on the Success of Minority Students on the PSAT
Creators: name: Brenner, Paul
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: subject: Education -- Research papers (Graduate)

description: The purpose of this study was to determine what effect stereotype threat might have on student success on the PSAT when the students attend a school composed primarily of minority students. The participants were enrolled in a county school’s Gifted and Talented and Honors Geometry classes during the 2013-2014 school year. The first measurement tool had participants complete a survey on stereotype threat and student performance. These answers were linked to the student PSAT scores, which was used as a second measurement tool. This study implemented a descriptive design. The data collected was analyzed for patterns based on student responses and the mean PSAT scores of students that felt similarly. Findings showed that the participants that felt the pressure of stereotype threat and felt that they were accountable for their actions had higher mean PSAT scores than their peers on the PSAT.
Coulombian disorder in Charge Density Waves
Creators: name: Rosso, Alberto
name: Orignac, Edmond
name: Chitra, R.
name: Giamarchi, Thierry
Publisher: name: arXiv
Year: 2006
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: When unscreened charged impurities are introduced in charge density wave system the long wavelength component of the disorder is long ranged and dominates static correlation functions. We calculate the x-ray intensity and find that it is identical to the one produced by thermal fluctuations in a disorder-free smectic-A. We suggest that this effect could be observed in the blue bronze material K$_{0.3}$MoO$_3$ doped with charged impurities such as Vanadium.
description: 4 pages, Proceedings of ECRYS-2005 International Workshop on Electronic Crystal
The Effect of the Kodaly Music Methodology on Reading Fluency in Second Grade Students
Creators: name: Confair-Weimer, Erica
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: subject: Education -- Research papers (Graduate)

description: The purpose of this study was to examine the effects of the Kodály Music Methodology on the reading fluency of second grade students. The participants in this study were enrolled in a Baltimore County Public School for the 2013-2014 school year. All of the students received the Baltimore County Public Schools Music Curriculum while the treatment group was instructed primarily in the Kodály Methodolgy. The treatment group also participated in a take home study that focused on music literacy, sight reading, and pitch exploration all outlined by the Kodály Method. The study lasted over the course of 6 weeks with the participants receiving 50 minutes of instruction once a week, and then at home practice that was monitored by parents. While both groups increased their score on the post-test, the null hypothesis was retained.
Massive Stars as Cosmic Engines through the Ages
Creators: name: Maeder, Andre
name: Meynet, Georges
name: Ekstrom, Sylvia
name: Hirschi, Raphael
name: Georgy, Cyril
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Some useful developments in the model physics are briefly presented, followed by model results on chemical enrichments and WR stars. We discuss the expected rotation velocities of WR stars. We emphasize that the (C+O)/He ratio is a better chemical indicator of evolution for WC stars than the C/He ratios. With or without rotation, at a given luminosity the (C+O)/He ratios should be higher in regions of lower metallicity Z. Also, for a given (C+O)/He ratio the WC stars in lower Z regions have higher luminosities. The WO stars, which are likely the progenitors of supernovae SNIc and of some GRBs, should preferentially be found in regions of low Z and be the descendants of very high initial masses. Finally, we emphasize the physical reasons why massive rotating low Z stars may also experience heavy mass loss
description: 12 pages, 11 figures, to be published by CUP, F. Bresolin, P.A. Crowther, J. Puls Eds
Charactoceras estonicum Foerste 1924
Creators: name: Kröger, Björn
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Apsidoceratidae
Charactoceras

description: Genus Charactoceras Foerste, 1924
Type species
Trochoceras (?) baeri Meek & Worthen, 1866, Richmond, Indiana, USA, Whitewater Formation, late Katian, Ordovician; by original designation.
Diagnosis
Closely coiled, rapidly expanding conchs with dorsally impressed whorl cross section, with flattened venter and rounded sides that converge towards the dorsum; sutures essentially straight laterally but forming broad ventral and dorsal lobes; surface with transverse growth lines that form distinct hyponomic sinus on venter, and transverse ribs in early stages only; siphuncle between center and venter, with cyrtochoanitic septal necks, empty; segments expanding slightly within camerae.” (Adopted from Sweet 1964a.)
description: Published as part of Kröger, Björn, 2025, The Lyckholm acme of cephalopods - Review of the late Katian (Vormsi-Pirgu regional stages) Ordovician cephalopods of Estonia, pp. 1-169 in European Journal of Taxonomy 978 on page 53, DOI: 10.5852/ejt.2025.978.2801, http://zenodo.org/record/14988376
Impurity induced magnetic ordering in Sr$_2$RuO$_4$
Creators: name: Zinkl, Bastian
name: Sigrist, Manfred
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Ti substituting Ru in Sr$_2$RuO$_4$ in small concentrations induces incommensurate spin density wave order with a wave vector $\boldsymbol{Q} \simeq (2 π/3, 2 π/3)$ corresponding to the nesting vector of two out of three Fermi surface sheets. We consider a microscopic model for these two bands and analyze the correlation effects leading to magnetic order through non-magnetic Ti-doping. For this purpose we use a position dependent mean field approximation for the microscopic model and a phenomenological Ginzburg-Landau approach, which both deliver consistent results and allow us to examine the inhomogeneous magnetic order. Spin-orbit coupling additionally leads to spin currents around each impurity, which in combination with the magnetic polarization produce a charge current pattern. This is also discussed within a gauge field theory in both charge and spin channel. This spin-orbit coupling effect causes an interesting modification of the magnetic structure, if currents run through the system. Our findings allow a more detailed analysis of the experimental data for Sr$_{2}$Ru$_{1-x}$Ti$_{x}$O$_{4}$. In particular, we find that the available measurements are consistent with our theoretical predictions.
description: 17 pages, 12 figures
Probing minimal scattering events in enhanced backscattering of light using low-coherence induced dephasing
Creators: name: Kim, Young L.
name: Pradhan, Prabhakar
name: Subramanian, Hariharan
name: Liu, Yang
name: Kim, Min H.
name: Backman, Vadim
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We exploit low spatial coherence illumination to dephase time-reversed partial waves outside its finite coherence area, which virtually creates a controllable coherence volume and isolates the minimal number of scattering events from higher order scattering in enhanced backscattering (EBS, also known as coherent backscattering) of light. We report the first experimental evidence that the minimum number of scattering events in EBS is double scattering in discrete random media, which has been hypothesized since the first observation of EBS of light. We discuss several unique characteristics and potential applications of low-coherence EBS in weakly scattering random media.
description: 4 pages and 5 figures
The Self-Organization of Speech Sounds
Creators: name: Oudeyer, Pierre-Yves
Publisher: name: arXiv
Year: 2005
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Robotics (cs.RO)
subject: Dynamical Systems (math.DS)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: The speech code is a vehicle of language: it defines a set of forms used by a community to carry information. Such a code is necessary to support the linguistic interactions that allow humans to communicate. How then may a speech code be formed prior to the existence of linguistic interactions? Moreover, the human speech code is discrete and compositional, shared by all the individuals of a community but different across communities, and phoneme inventories are characterized by statistical regularities. How can a speech code with these properties form? We try to approach these questions in the paper, using the "methodology of the artificial". We build a society of artificial agents, and detail a mechanism that shows the formation of a discrete speech code without pre-supposing the existence of linguistic capacities or of coordinated interactions. The mechanism is based on a low-level model of sensory-motor interactions. We show that the integration of certain very simple and non language-specific neural devices leads to the formation of a speech code that has properties similar to the human speech code. This result relies on the self-organizing properties of a generic coupling between perception and production within agents, and on the interactions between agents. The artificial system helps us to develop better intuitions on how speech might have appeared, by showing how self-organization might have helped natural selection to find speech.
The Switch Point Algorithm
Creators: name: Aghaee, Mahya
name: Hager, William W.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: The Switch Point Algorithm is a new approach for solving optimal control problems whose solutions are either singular or bang-bang or both singular and bang-bang, and which possess a finite number of jump discontinuities in an optimal control at the points in time where the solution structure changes. Problems in this class can often be reduced to an optimization over the switching points. Formulas are derived for the derivative of the objective with respect to the switch points, the initial costate, and the terminal time. All these derivatives can be computed simultaneously in just one integration of the state and costate dynamics. Hence, gradient-based unconstrained optimization techniques, including the conjugate gradient method or quasi-Newton methods, can be used to compute an optimal control. The performance of the algorithm is illustrated using test problems with known solutions and comparisons with other algorithms from the literature.
Wave-function geometry of band crossing points in two-dimensions
Creators: name: Hwang, Yoonseok
name: Jung, Junseo
name: Rhim, Jun-Won
name: Yang, Bohm-Jung
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Geometry of the wave function is a central pillar of modern solid state physics. In this work, we unveil the wave-function geometry of two-dimensional semimetals with band crossing points (BCPs). We show that the Berry phase of BCPs are governed by the quantum metric describing the infinitesimal distance between quantum states. For generic linear BCPs, we show that the corresponding Berry phase is determined either by an angular integral of the quantum metric, or equivalently, by the maximum quantum distance of Bloch states. This naturally explains the origin of the $π$-Berry phase of a linear BCP. In the case of quadratic BCPs, the Berry phase can take an arbitrary value between 0 and $2π$. We find simple relations between the Berry phase, maximum quantum distance, and the quantum metric in two cases: (i) when one of the two crossing bands is flat; (ii) when the system has rotation and/or time-reversal symmetries. To demonstrate the implication of the continuum model analysis in lattice systems, we study tight-binding Hamiltonians describing quadratic BCPs. We show that, when the Berry curvature is absent, a quadratic BCP with an arbitrary Berry phase always accompanies another quadratic BCP so that the total Berry phase of the periodic system becomes zero. This work demonstrates that the quantum metric plays a critical role in understanding the geometric properties of topological semimetals.
description: 7+9 pages, 4+1 figures, published version
DLBFoam: An open-source dynamic load balancing model for fast reacting flow simulations in OpenFOAM
Creators: name: Tekgül, Bulut
name: Peltonen, Petteri
name: Kahila, Heikki
name: Kaario, Ossi
name: Vuorinen, Ville
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Numerical Analysis (math.NA)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Computational load imbalance is a well-known performance issue in multiprocessor reacting flow simulations utilizing directly integrated chemical kinetics. We introduce an open-source dynamic load balancing model named DLBFoam to address this issue within OpenFOAM, an open-source C++ library for Computational Fluid Dynamics (CFD). Due to the commonly applied operator splitting practice in reactive flow solvers, chemistry can be treated as an independent stiff ordinary differential equation (ODE) system within each computational cell. As a result of the highly non-linear characteristics of chemical kinetics, a large variation in the convergence rates of the ODE integrator may occur, leading to a high load imbalance across multiprocessor configurations. However, the independent nature of chemistry ODE systems leads to a problem that can be parallelized easily (called an embarrassingly parallel problem in the literature) during the flow solution. The presented model takes advantage of this feature and balances the chemistry load across available resources. Additionally, a reference mapping model is utilized to further speed-up the simulations. When DLBFoam it utilized with both these features enabled, a speed-up by a factor of 10 is reported for reactive flow benchmark cases. To the best of our knowledge, this model is the first open-source implementation of chemistry load balancing in the literature.
description: 30 pages, published version in Elsevier
Discovery of Radio Emission from Transient Anomalous X-ray Pulsar XTE J1810-197
Creators: name: Halpern, J. P.
name: Gotthelf, E. V.
name: Becker, R. H.
name: Helfand, D. J.
name: White, R. L.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the first detection of radio emission from any anomalous X-ray pulsar (AXP). Data from the Very Large Array (VLA) MAGPIS survey with angular resolution 6" reveals a point-source of flux density 4.5 +/- 0.5 mJy at 1.4 GHz at the precise location of the 5.54 s pulsar XTE J1810-197. This is greater than upper limits from all other AXPs and from quiescent states of soft gamma-ray repeaters (SGRs). The detection was made in 2004 January, 1 year after the discovery of XTE J1810-197 during its only known outburst. Additional VLA observations both before and after the outburst yield only upper limits that are comparable to or larger than the single detection, neither supporting nor ruling out a decaying radio afterglow related to the X-ray turn-on. Another hypothesis is that, unlike the other AXPs and SGRs, XTE J1810-197 may power a radio synchrotron nebula by the interaction of its particle wind with a moderately dense environment that was not evacuated by previous activity from this least luminous, in X-rays, of the known magnetars.
description: 13 pages, 1 figure, to appear in ApJ Letters
Hints on the quadrupole deformation of the $Δ$(1232)
Creators: name: Fernandez-Ramirez, C.
name: de Guerra, E. Moya
name: Udias, J. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The E2/M1 ratio (EMR) of the $Δ$(1232) is extracted from the world data in pion photoproduction by means of an Effective Lagrangian Approach (ELA).This quantity has been derived within a crossing symmetric, gauge invariant, and chiral symmetric Lagrangian model which also contains a consistent modern treatment of the $Δ$(1232) resonance. The \textit{bare} s-channel $Δ$(1232) contribution is well isolated and Final State Interactions (FSI) are effectively taken into account fulfilling Watson's theorem. The obtained EMR value, EMR$=(-1.30\pm0.52)$%, is in good agreement with the latest lattice QCD calculations [Phys. Rev. Lett. 94, 021601 (2005)] and disagrees with results of current quark model calculations.
description: Enlarged conclusions and explanations on the E2/M1 ratio. Figure 3 improved. References updated. 5 pages. 3 figures. 2 tables. Accepted for publication in Physical Review C
[Photographs of Fred and Rosie Collins]
Creators: name: Collins, Fred
name: Collins, Rose
name: Klein, Carol
name: Klein, Sheldon
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2015
Subjects: subject: xaw
subject: Kawaiisu language

description: Prints of three pictures of Fred and Rosie Collins taken by Sheldon Klein in 1958. Includes one index card with a list of language consultants Klein worked with in his fieldwork in Tehachapi in the early 1980s.
Remote state preparation of two-component Bose-Einstein condensates
Creators: name: Chaudhary, Manish
name: Fadel, Matteo
name: Ilo-Okeke, Ebubechukwu O.
name: Pyrkov, Alexey N.
name: Ivannikov, Valentin
name: Byrnes, Tim
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A protocol for remote state preparation is proposed for spin ensembles, where the aim is to prepare a state with a given set of spin expectation values on a remote spin ensemble using entanglement, local spin rotations, and measurements in the Fock basis. The spin ensembles could be realized by thermal atomic ensembles or spinor Bose-Einstein condensates. The protocol works beyond the Holstein-Primakoff approximation, such that spin expectation values for the full Bloch sphere can be prepared. The main practical obstacle is the preparation of the maximally entangled state between the spin ensembles. To overcome this, we examine using states based on the two-axis two-spin (2A2S) Hamiltonian in place of the maximally entangled state and examine its performance. We find that the version of the protocol with 2A2S squeezing well-approximates the maximally entangled state, such that spin averages can be remotely prepared. We evaluate the errors of using 2A2S squeezed states, and find that it decreases with the ensemble size. With post-selection, errors can be systematically decreased further.
description: 12 pages, 6 figures
Preservation in Practice: Adaptive Use of Historic Buildings as Arts Facilities in the San Francisco Bay
Creators: name: Fry, Julie
Publisher: name: Maryland Shared Open Access Repository
Year: 2012

description: Julia Rogers Research Prize: Graduate Winner, 2012
description: As a mature student, I had not researched and written a term paper in over thirty years. The last time I did so, I wrote the paper on a manual typewriter, and spent many happy hours in my university library, hoping to find relevant source material. Oh, how things have changed, and yet, interestingly, have stayed the same! Good research requires a keen understanding of the questions to ask, and that will never go away. However, the tools for obtaining information and historical research have proliferated well beyond the library stacks and card catalogs of my past.
My approach to writing this paper was to select a topic of interest and relevance to my career and studies, but also one that enabled me to include primary research. I wanted to combine both library sources and contemporary perspectives in how old buildings in the Bay Area have been adapted and used as arts venues. The four buildings I selected were all built in the first quarter of the 20th century and adapted within the last forty years. I was able to speak with the executive directors of the resident arts organizations included, as well as architects involved in the projects. As I hoped, I was also able to spend time in libraries across the country. All had books and periodicals of use. But the wonder of the internet now means that I was able to look for research material on my local library’s website and order a copy from anywhere in the country, that archived materials in the Stanford University Library were at my fingertips, that I could find information in books, periodicals, and studies online, without having to leave my desk.
description: Dr. Richard Wagner
Competitiveness of U.S. Meats in Japan and South Korea: A Source Differentiated Market Study
Creators: name: Mutondo, Joao E.
name: Henneberry, Shida Rastegari
name: Mutondo, Joao E.
name: Henneberry, Shida Rastegari
Publisher: name: Unknown
Year: 2007
Subjects: subject: Demand and Price Analysis
subject: BSE
subject: competitive advantage
subject: FMD
subject: Japanese meat demand
subject: RSDAIDS
subject: South Korean Meat Demand

description: The restricted source differentiated almost ideal demand system (RSDAIDS) is used to estimate the parameters of the Japanese and South Korean source differentiated meat demand models. Expenditure and own-price elasticities indicate that Japanese beef, Canadian and Danish pork, and Brazilian and Thai poultry have a competitive advantage in Japan. The BSE outbreak in Japan decreased the shares of Japanese and U.S. beef. Regarding South Korea, the results indicate that imported beef from the U.S. and Australia, Danish pork, and South Korean and Thai poultry have a competitive advantage. The U.S. BSE outbreak decreased the market shares of U.S. beef in the South Korean beef market.
Stochastic monotonicity and the Markov product for copulas
Creators: name: Siburg, Karl Friedrich
name: Strothmann, Christopher
Publisher: name: arXiv
Year: 2020
Subjects: subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62H05, 37A30

description: Given two random variables $X$ and $Y$, stochastic monotonicity describes a monotone influence of $X$ on $Y$. We prove two different characterizations of stochastically monotone $2$-copulas using the isomorphism between $2$-copulas and Markov operators. The first approach establishes a one-to-one correspondence between stochastically monotone copulas and monotonicity-preserving Markov operators. The second approach characterizes stochastically monotone copulas by their monotonicity property with respect to the Markov product. Applying the latter result, we identify all idempotent stochastically monotone copulas as ordinal sums of the independence copula $Π$.