cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Confirmation of X-Ray Absorption by WHIM in the Sculptor Wall
Creators: name: Fang, Taotao
name: Buote, David A.
name: Humphrey, Philip J.
name: Canizares, Claude R.
name: Zappacosta, Luca
name: Maiolino, Roberto
name: Tagliaferri, Gianpiero
name: Gastaldello, Fabio
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In a previous paper we reported a 3-sigma detection of an absorption line from the Warm-Hot Intergalactic Medium (WHIM) using the Chandra and XMM X-ray grating spectra of the blazar H2356-309, the sight-line of which intercepts the Sculptor Wall, a large-scale superstructure of galaxies at z ~ 0.03. To verify our initial detection, we obtained a deep (500 ks), follow-up exposure of H2356-309 as part of the Cycle-10 Chandra Large Project Program. From a joint analysis of the Cycle-10 and previous (Cycle-8) Chandra grating data we detect the redshifted OVII WHIM line at a significance level of 3.4-sigma, a substantial improvement over the 1.7-sigma level reported previously when using only the Cycle-8 data. The significance increases to 4.0-sigma when the existing XMM grating data are included in the analysis, thus confirming at higher significance the existence of the line at the redshift of the Sculptor Wall with an equivalent width of 28.5+/-10.5 mA (90% confidence). We obtain a 90% lower limit on the OVII column density of 0.8 10^16 cm^-2 and a 90% upper limit on the Doppler-b parameter of 460 km/s. Assuming the absorber is uniformly distributed throughout the ~ 15 Mpc portion of the blazar's sight-line that intercepts the Sculptor Wall, that the OVII column density is ~ 2 10^16 cm^-2 (corresponding to b > 150 km/s where the inferred column density is only weakly dependent on b), and that the oxygen abundance is 0.1 solar, we estimate a baryon over-density of ~ 30 for the WHIM, which is consistent with the peak of the WHIM mass fraction predicted by cosmological simulations. The clear detection of OVII absorption in the Sculptor Wall demonstrates the viability of using current observatories to study WHIM in the X-ray absorption spectra of blazars behind known large-scale structures.
description: 11 pages, 6 figures; accepted for publication in the Astrophysical Journal; minor revisions to match the accepted version; conclusions unchanged.
Isolation and phosphorylation of guinea pig cardiac sarcolemma
Creators: name: Hui, Chi Wai
Publisher: name: University of British Columbia
Year: 2010

description: Plasma membranes were prepared from guinea pig heart by homogenizing the tissue in a Polytron homogenizer, followed by four cycles of washing and differential centrifugation using low g forces (380 x g/10 minutes to 120 x g/10 minutes). The crude particles thus obtained were extracted with KCl (1.25 M), followed by isopycnic centrifugation in a discontinuous sucrose gradient. Adenylate cyclase was purified 10-15 fold over the whole homogenate with a specific activity of 3.6±0.72 nmoles/mg/minute. Ouabain-sensitive Mg⁺⁺-dependent Na⁺+K⁺-ATPase, another plasma membrane specific enzyme, was enriched by 4 fold, with a specific activity of 107±8.2 nmoles/mg/minute. Cytochrome C oxidase, an enzyme predominantly of mitochondrial origin, was recovered in low yield. These membrane "marker" enzyme studies indicated that the isolated membrane preparation consisted of highly purified plasma membranes. Functional studies with the cardiac sarcolemma indicated that an ATP-dependent Ca⁺⁺ binding system as well as Ca⁺⁺-dependent ATPases were present. Intrinsic protein kinase activities and membrane-bound substrates for phosphorylation were also found to be associated with these membranes, which were phosphorylated by endogenous or added protein kinase. Membrane phosphorylation was stimulated by cyclic AMP (1 μM) and was reversed by a membrane-bound phosphoprotein phosphatase, indicating the presence of a phosphorylation-dephosphorylation system in cardiac sarcolemma. Plasma membranes, when phosphor-ylated, were capable of accumulating twice as much Ca⁺⁺ as control preparations. For each nanomole of phosphate incorporated into the membrane, there were 15 nanomoles of net increase in Ca⁺⁺ uptake. These data are consistent with the possibility that cyclic AMP may facilitate Ca⁺⁺ movement into the cardiac cell via a phosphorylation-dephosphorylation mechanism.
title: Does Teaching Narrative Structure to Children with Language Impairments Improve Comprehension of Expository Text?
Creators: name: Evans, Brynne Cook
Publisher: name: Utah State University
Year: 2013

description: Research has shown that knowledge of narrative text structure enhances students’ abilities to comprehend and produce narrative discourse. The current study was designed to determine if training in narrative text structure was associated with improved comprehension for expository passages that adhered to a narrative structure. Six children between the ages of 5:3 and 9:7 with language impairments participated. Children were matched by grade and randomly assigned to the intervention or control group. Participants in the intervention group received instruction 2 times a week for 45-minute sessions for a duration of 12 weeks from a graduate student in speech-language pathology with 80% supervision by a certified speech-language pathologist. A literature- based narrative intervention that centered on knowledge of story grammar components, use of new vocabulary and grammatical structures, as well as, answering comprehension questions and retelling stories was utilized. Narrative outcomes and expository outcomes were measured before and after intervention. Narrative outcome measures included the Test of Narrative Language Index Score (TNLAI) and the Monitoring Indicators of Scholarly Language rubric (MISL) analyzing a single scene narrative. Expository outcomes included two expository passages provided to each participant. After the participants were told the expository passage, they were asked to answer explicit and implicit comprehension questions about the passage as well as recall the passage in its entirety. Inter-rater reliability was determined to be 85% or above for scoring of all measures. Analysis of pre-test measurements found no significant difference between the groups. A series of one-way analysis of variance tests were conducted to evaluate whether children who received narrative instruction differed from children who did not receive instruction on the narrative and expository dependent variables after intervention. The ANOVAs conducted to test the relationship between group and narrative outcomes were significant favoring the experimental group for the TNLAI and the MISL scores. The ANOVAs conducted to test the relationship between group and expository outcomes were also significantly favoring the experimental group for the number of comprehension questions answered correctly, but not for the number of story details recalled. The implications of these results are discussed.
QCD and the Hagedorn spectrum
Creators: name: Cohen, Thomas D.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: It is shown that large Nc QCD must have a Hagedorn spectrum (i.e. a spectrum of hadron which grows exponentially with the hadrons mass) provided that certain technical assumptions concerning the applicability of perturbation theory to a certain class of correlation functions apply. The basic argument exploits the interplay of confinement and asymptotic freedom.
description: 16 pages, 1 figure. This version is expanded from the original version. Additional discussion has been added to clarify the central issues. Typos have been fixed. The appendix has been updated and greatly expanded.
Verifiable conditions of $\ell_1$-recovery of sparse signals with sign restrictions
Creators: name: Iouditski, Anatoli
name: Karzan, Fatma Kilinc
name: Nemirovski, Arkadii S.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistics Theory (math.ST)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We propose necessary and sufficient conditions for a sensing matrix to be "s-semigood" -- to allow for exact $\ell_1$-recovery of sparse signals with at most $s$ nonzero entries under sign restrictions on part of the entries. We express the error bounds for imperfect $\ell_1$-recovery in terms of the characteristics underlying these conditions. Furthermore, we demonstrate that these characteristics, although difficult to evaluate, lead to verifiable sufficient conditions for exact sparse $\ell_1$-recovery and to efficiently computable upper bounds on those $s$ for which a given sensing matrix is $s$-semigood. We concentrate on the properties of proposed verifiable sufficient conditions of $s$-semigoodness and describe their limits of performance.
title: A Validation and Comparison About VABS-IDE and VABS-GUI
Creators: name: Hu, Teng
Publisher: name: Utah State University
Year: 2012

description: Variational Asymptotic Beam Section (VABS) analysis is a computer code for design and analysis of slender structure such as rotor blades, wind turbine blades, missiles, and rockets more efficiently than a full three-dimensional finite element analysis. VABS enables a rigorously a dimensional reduction of the original three-dimensional nonlinear analysis into a one-dimensional nonlinear beam analysis and a two-dimensional linear cross-sectional analysis. The VABS code has been extensively used in academia and industry for comput- ing the sectional properties and recovering three-dimensional fields of composite slender structures. Recently two graphic user interface, namely VABS-IDE and VABS-GUI, have been developed to automatic the preprocessing and postprocessing for the VABS software. This report uses a few benchmark examples, including a circular aluminum tube, a highly heterogeneous section, a multi-layer composite pipe, and an isotropic blade-like section to validate and compare both tools. And also this report studies the mesh convergence of VABS and loss of accuracy using smeared properties, two questions raised by an industry user.
Non-Gaussian Probability Distribution for the CMB Angular Power Spectra?
Creators: name: Golovnev, Alexey
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: This is my contribution to Proceedings of the International Workshop on Cosmic Structure and Evolution, September 23-25, 2009, Bielefeld, Germany. In my talk I presented some non-Gaussian features of the foreground reduced WMAP five year full sky temperature maps, which were recently reported in arXiv:0906.4954 paper by V.Vanchurin. And in these notes I first discuss the statistics behind this analysis in some detail. Then I describe invaluable insights which I got from discussions after my talk on the Workshop. And finally I explain why, in my current opinion, the signal detected in arXiv:0906.4954 can hardly have something to do with cosmological perturbations, but rather it presents a fancy measurement of the Milky Way angular width in the microwave frequency range.
description: A contribution to Proceedings of the International Workshop on Cosmic Structure and Evolution, September 23-25, 2009, Bielefeld, Germany. 6 pages, 1 figure
Superconductivity induced by doping Platinum in BaFe2As2
Creators: name: Zhu, Xiyu
name: Han, Fei
name: Mu, Gang
name: Tang, Jun
name: Ju, Jing
name: Tanigaki, Katsumi
name: Wen, Hai-Hu
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: By substituting Fe with the 5d-transition metal Pt in BaFe2As2, we have successfully synthesized the superconductors BaFe2-xPtxAs2. The systematic evolution of the lattice constants indicates that the Fe ions were successfully replaced by Pt ions. By increasing the doping content of Pt, the antiferromagnetic order and structural transition of the parent phase is suppressed and superconductivity emerges at a doping level of about x = 0.02. At a doping level of x = 0.1, we get a maximum transition temperature Tc of about 25 K. The synchrotron powder x-ray diffraction shows that the resistivity anomaly is in good agreement with the structural transition. The superconducting transitions at different magnetic fields were also measured at the doping level of about x = 0.1, yielding a slope of -dHc2/dT = 5.4 T/K near Tc. A phase diagram was established for the Pt doped 122 system. Our results suggest that superconductivity can also be easily induced in the FeAs family by substituting the Fe with Pt, with almost the similar maximum transition temperatures as doping Ni, Co, Rh and Ir.
description: 6 pages, 5 figures
Finite-Size Geometric Entanglement from Tensor Network Algorithms
Creators: name: Shi, Qian-Qian
name: Orus, Roman
name: Fjaerestad, John Ove
name: Zhou, Huan-Qiang
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The global geometric entanglement is studied in the context of newly-developed tensor network algorithms for finite systems. For one-dimensional quantum spin systems it is found that, at criticality, the leading finite-size correction to the global geometric entanglement per site behaves as $b/n$, where $n$ is the size of the system and $b$ a given coefficient. Our conclusion is based on the computation of the geometric entanglement per spin for the quantum Ising model in a transverse magnetic field and for the spin-1/2 XXZ model. We also discuss the possibility of coefficient $b$ being universal.
description: 5 pages, 2 figures, and 3 tables.
Effect of Sm-, Gd- codoping on structural modifications in aluminoborosilicate glasses under beta-irradiation
Creators: name: Malchukova, Evguenia
name: Boizot, Bruno
name: Petite, Guillaume
name: Ghaleb, Dominique
Publisher: name: arXiv
Year: 2008
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two series of Sm-, Gd-codoped aluminoborosilicate glasses with different total rare earth content have been studied in order to examine the codoping effect on the structural modifications of beta-irradiated glasses. The data obtained by Electron Paramagnetic Resonance spectroscopy indicated that relative amount of Gd3+ ions located in network former position reveals non-linear dependence on Sm/Gd ratio. Besides, codoping leads to the evolution of the EPR signal attributed to defects created by irradiation: superhyperfine structure of boron oxygen hole centres EPR line becomes less noticeable and resolved with increase of Gd amount. This fact manifests that Gd3+ ions are mainly diluted in vicinity of the boron network. By Raman spectroscopy, we showed that the structural changes induced by the irradiation also reveal non-linear behaviour with Sm/Gd ratio. In fact, the shift of the Si-O-Si bending vibration modes has a clear minimum for the samples containing equal amount of Sm and Gd (50:50) in both series of the investigated glasses. In contrast, for single doped glass there is no influence of dopant's content on Si-O-Si shift (in case of Gd) or its diminution (in case of Sm) occurs which is explained by the reduction process influence. At the same time, no noticeable effect of codoping on Sm3+ intensity as well as on Sm2+ emission or on Sm reduction process was observed.
title: Power Efficient Restart-Capable Acrylonitrile Butadiene Styrene-Based Arc Ignition for Hybrid Rocket Motors
Creators: name: Inkley, Nathan R.
Publisher: name: Utah State University
Year: 2013

description: Hybrid rocket ignition has historically involved either dangerous energetic materials or inefficient and failure-prone plasma sources. The vast majority of such systems cannot sup- port multiple restart cycles, thus limiting the applicability of hybrid rockets–especially for in-space propulsion. During research investigating its use as a fuel for hybrid rockets, it was discovered that Acrylonitrile Butadiene Styrene (ABS) plastic possesses unique electrical breakdown characteristics. During a properly designed breakdown event, application of a strong electric field induces a high-temperature arc along the surface of the ABS, concurrent with rapid production of hydrocarbon vapor. This behavior forms the basis of a novel ABS arc ignition system. Several such systems were designed, built and tested. Minimum conditions for successful operation were discovered, including minimum ignition pressure and electrical power requirements. Hands-off restart capability was demonstrated repeatedly. Finally, paths of inquiry for future research are outlined.
title: Anti-Corruption Efforts and Russian Perceptions: Presidents Putin and Menvedev's Efforts to Influence Perceptions of Corruption
Creators: name: Kendall, Jeris
Publisher: name: Utah State University
Year: 2013

description:

The problems affecting Russia because of corruption are serious and pressing. Police officers, judges, government officials, and many others are involved in taking bribes for services or benefits they provide. These actions are contrary to the laws they are to follow, and they are preventing the rule of law from operating properly in Russia. In order to resolve this issue Russia needs to understand how corruption works against national progress, how society perceives the efforts of Russian presidents in the battle against corruption, and how those perceptions can be utilized to help improve the situation.
Some new near-normal sequences
Creators: name: Djokovic, Dragomir Z.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05B20, 05B30

description: The normal sequences NS(n) and near-normal sequences NN(n) play an important role in the construction of orthogonal designs and Hadamard matrices. They can be identified with certain base sequences (A;B;C;D), where A and B have length n+1 and C and D length n. C.H. Yang conjectured that near-normal sequences exist for all even n. While this has been confirmed for n not exceeding 30, so far nothing else was known for larger n. We show that NN(32) consists of 8 equivalence classes and we exhibit their representatives. We also construct representatives for two equivalence classes of NN(34). On the other hand our exhaustive computer searches show that NS(31) and NS(33) are void.
description: 7 pages, 1 table
title: Business Aviation: Utilization, Benefits, and Value
Creators: name: Roberts, Tony
Publisher: name: Utah State University
Year: 2013

description: In this study, I compare the performance of U.S. companies that use their own aviation transportation for business purposes (users) and those that use commercial transportation (non-users). I conduct qualitative analysis by interviewing CEOs and CFOs of various companies that are both users and non-users. Interviews of CEO’s and CFO’s coupled with numerical evidence are considered to determine advantages or disadvantages of business aviation. Data from the S&P 500 is used to calculate and provide explanation of how using business aviation affects the firms value, profitability, and asset utilization. Using both CAPM and Fama-French Three Factor model, I assess the expected returns of firms who are users compared to those who are not. Findings suggest that users have a competitive edge relative to non-users. I am able to conclude that business aviation is a tool and asset in assisting firms to run more efficient and maintain better relationships with clients. Firms who utilize business aviation receive many benefits while providing value to shareholders.
VEDA: Empowering Open Science for Earth Observation Data
Creators: name: Adhikari, Slesa
name: Kirk, Alexandra
name: Marouane, Abdelhak
name: Solvsteen, Jonas
name: Boyd, Anthony
name: Barciauskas, Aimee
name: Freitag, Brian
name: Maskey, Manil
Publisher: name: NASA Marshall Space Flight Center
Year: 2023
Subjects: Data Science
Earth Science
Open Science
Data Analysis
Data Visualization
Data Exploration
NASA Earth Science
NASA
AGU 2023
FAIR
Platform as a Service

description: Presentation Abstract

Open science has emerged as a transformative approach to scientific research, fostering inclusivity, accessibility, and reproducibility. Developed by NASA, Visualization, Exploration and Data Analysis (VEDA) stands as a powerful open science platform, aiming to facilitate discovery, interactive visualization, and Earth observation data analysis.

VEDA’s foundation lies in its commitment to openness and inclusivity. By intelligently integrating community-standard open-source software and interfaces, VEDA offers an open Earth data science environment. Notable components include the Spatio-Temporal Asset Catalog (STAC) storage and APIs, OGC-standard dynamic tiling for raster and vector data, and the community-friendly JupyterLab interface. Additionally, VEDA presents a novel, lightweight, and customizable website (dashboard), enhancing data discovery, light analytics, and storytelling capabilities.

VEDA's forward-thinking approach embraces cloud-native technology, harnessing the power of analysis-ready, cloud-optimized (ARCO) data in cloud-optimized GeoTIFFs (COGs) and Zarr formats. This approach transcends traditional data compatibility barriers, ensuring efficient data access and exploration.

Accessibility and reproducibility are key to open science. VEDA makes data, visualization, and analysis accessible to the global scientific community via the dashboard and APIs. Further, science insights published on the dashboard are reproducible through VEDA’s JupyterHub.

In this workshop session, we intend to showcase the seamless transition from the VEDA dashboard to the JupyterHub environment, demonstrating how researchers can "jump into" open science. Our exploration will encompass the discovery, visualization, and analysis of VEDA datasets through the accessible VEDA APIs. Notably, this knowledge can be seamlessly extended to embrace a wider array of community tools, emphasizing the versatility and applicability of VEDA beyond its core platform.
title: The Effects of Mnemonics to Increase Accuracy of Multiplication Facts in Upper-Elementary School Students with Mild to Moderate Disabilities
Creators: name: Eubanks, Logan James
Publisher: name: Utah State University
Year: 2013

description: The intent of this project is to replicate a specific instructional method used in Wood et al.’s study focusing on the use of the pegword mnemonic strategy paired with stories and illustrations for 15 targeted multiplication facts remaining after mastering math facts in the zeros, ones, twos, fives, or nines groups. Three questions will be asked during this project on the effects of mnemonic instruction using pegword strategies on the percentage of multiplication facts answered correctly by third, fourth, and fifth grade students with learning disabilities? 1) Does pegword instruction paired with stories and illustrations result in immediate improvement for the specific multiplication facts taught? 2) Are students’ performances on previously taught multiplication facts maintained as new multiplication facts are introduced? 3) Do students maintain accuracy on 2 and 4 week follow-up tests?
Remarks on endomorphisms and rational points
Creators: name: Amerik, Ekaterina
name: Bogomolov, Fedor
name: Rovinsky, Marat
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14G05

description: Let X be a variety over a number field and let f: X --> X be an "interesting" rational self-map with a fixed point q. We make some general remarks concerning the possibility of using the behaviour of f near q to produce many rational points on X. As an application, we give a simplified proof of the potential density of rational points on the variety of lines of a cubic fourfold (originally obtained by Claire Voisin and the first author in 2007).
description: LaTeX, 22 pages. v2: some minor observations added, misprints corrected, appendix modified.
title: Sd de Herlin Werner Wunderlinch
Creators: name: Quintana de la Cruz, Rosa
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Ultrasound
subject: CT
subject: MR
subject: Kidney
subject: Genital / Reproductive system female

description: Objetivo docente
Revisión del tema
Conclusiones
Bibliografía
description: Objetivo docente:
El S.H.W.W es una anomalía congénita rara del tracto urogenital que afecta a los conductos de Müller y de Wolff .
Consiste en la triada útero didelfo,
obstrucción de hemivagina y agenesia renal ipsilateral . Fig. 1 Nuestro objetivo es presentar...
title: Land Use And Land Cover Dynamics Under Climate Change In Urbanizing Intermountain West: A Case Study From Cache County, Utah
Creators: name: Li, Enjie
Publisher: name: Utah State University
Year: 2013

description: Climate change is tightly linked with urbanization. Urban development with increasing greenhouse gas emission worsens climate change, while climate change in turn influence hydroclimate and ecosystem functions, and indirectly affect urban systems. The Intermountain West is experiencing rapid urban growth, climate change interacting with urbanization poses new challenges to the Intermountain West. Urban planning needs to adapt to these new changes and constrains, and to develop new tools and plans to effectively respond to climate changes. An urban growth model SLEUTH is applied to predict the future urban growth and land use dynamics in the Intermountain west, using Cache County as a case study. Through the creation of scenarios, model outputs provide best estimates of future land use dynamics and urban growth under different policy and management conditions related to climate change scenarios. The success of integrating climate change into urban planning model opened up the opportunities for planners and decisions makers to foresee the potential consequences brought by individual policy or management, and to better address climate change issues in the “transitional” urban environment.
title: Ca de recto: Estadificación y planificación quirúrgica mediante RM
Creators: name: Lorenzo Quesada, Verónica
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Neoplasia
subject: Staging
subject: MR
subject: Gastrointestinal tract
subject: Abdomen

description: Objetivo docente
Revisión del tema
Conclusiones
Bibliografía
description: Objetivo docente:
-Describir la técnica de RM utilizada en la estadificación preoperatoria del Ca de recto. -Enumerar los puntos clave que son necesarios reseñar en un informe radiológico para la estadificacion del Ca de recto. -Describir los hallazgos...
title: Toxina botulínica en el dolor miofascial lumbar
Creators: name: Mullor Delgado, Luis Alberto
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Puncture
subject: Education
subject: Fluoroscopy
subject: Musculoskeletal soft tissue
subject: Interventional non-vascular

description: Objetivo docente
Revisión del tema
Conclusiones
Bibliografía
description: Objetivo docente:
Conocer los procedimientos intervencionistas para tratar el dolor miofascial lumbar,
mediante la técnica de infiltración de los músculos profundos de la cintura pelviana,
bajo control fluoroscópico,
con contraste radiológico. Revisar las...
Structured Variable Selection with Sparsity-Inducing Norms
Creators: name: Jenatton, Rodolphe
name: Audibert, Jean-Yves
name: Bach, Francis
Publisher: name: arXiv
Year: 2009
Subjects: subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We consider the empirical risk minimization problem for linear supervised learning, with regularization by structured sparsity-inducing norms. These are defined as sums of Euclidean norms on certain subsets of variables, extending the usual $\ell_1$-norm and the group $\ell_1$-norm by allowing the subsets to overlap. This leads to a specific set of allowed nonzero patterns for the solutions of such problems. We first explore the relationship between the groups defining the norm and the resulting nonzero patterns, providing both forward and backward algorithms to go back and forth from groups to patterns. This allows the design of norms adapted to specific prior knowledge expressed in terms of nonzero patterns. We also present an efficient active set algorithm, and analyze the consistency of variable selection for least-squares linear regression in low and high-dimensional settings.
Torsion in string-inspired cosmologies and the universe dark sector
Creators: name: Mavromatos, Nick E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: I review several aspects of torsion in string-inspired cosmologies. In particular, I discuss its connection with fundamental, string-model independent, axion fields associated with the massless gravitational multiplet of the string. I argue in favour of the role of primordial gravitational anomalies coupled to such axions in inducing inflation of a type encountered in the "running-vacuum-model (RVM)" cosmological framework, without fundamental inflaton fields. The gravitational-anomaly terms owe their existence to the Green-Schwarz mechanism for the (extra-dimensional) anomaly cancellation, and may be non-trivial in such theories in the presence of (primordial) gravitational waves at early stages of the four-dimensional string Universe (after compactification). I also discuss how the torsion-induced stringy axions can acquire a mass in the post inflationary era, due to non perturbative effects, thus having the potential to play the rôle of (a component of) dark matter in such models. Finally, I describe briefly the current-era phenomenology of this model, with the emphasis placed on the possibility of alleviating tensions observed in the current-era cosmological data. A brief phenomenological comparison with other cosmological models in contorted geometries is also made.
description: 37 pages revtex, 2 pdf figures incorporated.References and Subsection IV.C added, on potential primordial black hole effects on gravitational waves during inflation. No effects on conclusions. Version to be published in special issue of Universe "Beyond Riemannian Geometry in Classical and Quantum Gravity" (Guest eds. Marco Danilo Claudio Torri, Christian Pfeifer and Nicoleta Voicu)
Community building in Scientific open source in latin america
Creators: name: Peña-Castellanos, Gonzalo Andrés
Publisher: name: Zenodo
Year: 2021
Subjects: Latin america, Open Source

description: The CZI mission to "cure, prevent, or manage all diseases by the end of the century" implicitly requires reaching everyone on Earth, which creates an imperative for Open Science to have global reach. This requires situated (e.g., in the local language, locally and culturally grounded) Open Science organizations that flourish in their local context. Our presenters will discuss their experience with efforts building Open Source and Open Science in Latin America.
Self-assembly of amphiphilic peanut-shaped nanoparticles
Creators: name: Whitelam, Stephen
name: Bon, Stefan A. F.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We use computer simulation to investigate the self-assembly of Janus-like amphiphilic peanut-shaped nanoparticles, finding phases of clusters, bilayers and micelles in accord with ideas of packing familiar from the study of molecular surfactants. However, packing arguments do not explain the hierarchical self-assembly dynamics that we observe, nor the coexistence of bilayers and faceted polyhedra. This coexistence suggests that experimental realizations of our model can achieve multipotent assembly of either of two competing ordered structures.
title: Afasias: de Broca y Wernicke a un complejo sistema del lenguaje cortico-subcortical
Creators: name: Carreño Morán, Patricia
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Ischaemia / Infarction
subject: Speech disorders
subject: Localisation
subject: SPECT-CT
subject: MR-Functional imaging
subject: Neuroradiology brain
subject: Neoplasia

description: Objetivos
Material y método
Resultados
Conclusiones
Bibliografía
description: Objetivos:
La afasia se define como una pérdida en la función del lenguaje causada por una lesión orgánica en una determinada área del cerebro originando un déficit patológico en la expresión y/o comprensión del lenguaje oral y escrito,
originado los...
A correlation between the spectral and timing properties of AGN
Creators: name: Papadakis, I. E.
name: Sobolewska, M.
name: Arevalo, P.
name: Markowitz, A.
name: McHardy, I. M.
name: Miller, L.
name: Reeves, J. N.
name: Turner, T. J.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the results from a combined study of the average X-ray spectral and timing properties of 14 nearby AGN. For 11 of the sources in the sample, we used all the available data from the RXTE archive, which were taken until the end of 2006. There are 7795 RXTE observations in total for these AGN, obtained over a period of ~7-11 years. We extracted their 3-20 keV spectra and fitted them with a simple power-law model, modified by the presence of a Gaussian line (at 6.4 keV) and cold absorption, when necessary. We used these best-fit slopes to estimate the mean spectral slope for each object, while we used results from the literature to estimate the average spectral slope of the three objects without archival, monitorin RXTE data. Our results show that the AGN average spectral slopes are not correlated either with the black hole mass or the characteristic frequencies that were detected in the power spectra.They are positively correlated, though, with the characteristic frequency when normalised to the sources black hole mass. This is similar to the spectral-timing correlation that has been observed in Cyg X-1, but not the same.The AGN spectral-timing correlation can be explained if we assume that the accretion rate determines both the average spectral slope and the characteristic time scales in AGN. The spectrum should steepen and the characteristic frequency should increase, proportionally, with increasing accretion rate. We also provide a quantitative expression between spectral slope and accretion rate. Thermal Comptonisation models are broadly consistent with our result, but only if the ratio of the soft photons' luminosity to the power injected to the hot corona is proportionally related to the accretion rate.
description: 10 pages, 3 figures
title: Nuevo Consenso Para la Valoración de la RM de Columna Vertebral en las Espondiloartritis Axiales
Creators: name: Alonso Torres, Ana
Publisher: name: Sociedad Española de Radiología Médica
Year: 2014
Subjects: subject: Musculoskeletal spine
subject: MR
subject: Education
subject: Diagnostic procedure
subject: Oedema
subject: Inflammation

description: Objetivo docente
Revisión del tema
Conclusiones
Bibliografía
description: Objetivo docente:
- Presentar propuesta del grupo ASAS/OMERACT sobre lesiones de Espondiloartritis Axial en columna vertebral,
con hallazgos característicos y definición de “RM positiva” para inflamación. - Comentar requisitos técnicos imprescindibles y...
Circular Orbits in Extremal Reissner Nordstrom Spacetimes
Creators: name: Pradhan, Parthapratim
name: Majumdar, Parthasarathi
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Circular null geodesic orbits, in extremal Reissner-Nordstrom spacetimes, are examined with regard to their stability, and compared with similar orbits in the near-extremal situation. Extremization of the effective potential for null circular orbits shows the existence of a stable circular geodesic in the extremal spacetime, precisely {\it on} the event horizon, which coincides with its null geodesic generator. Such an orbit also emerges as a global minimum of the effective potential for circular {\it timelike} orbits. This type of geodesic is of course absent in the corresponding near-extremal spacetime, as we show here, testifying to differences between the extremal limit of a generic RN spacetime and the exactly extremal geometry.
description: 13 Pages Latex 2e, no figures; title of paper, abstract and contents modified substantively following critique of anonymous referee
L^p solutions of the steady-state Navier-Stokes equations with rough external forces
Creators: name: Bjorland, Clayton
name: Brandolese, Lorenzo
name: Iftimie, Dragos
name: Schonbek, Maria Elena
Publisher: name: arXiv
Year: 2009
Subjects: subject: Analysis of PDEs (math.AP)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: In this paper we address the existence, the asymptotic behavior and stability in $L^p$ and $L^{p,\infty}$, 3/2.
description: 2nd version revised according to referee's remarks. To appear in Comm. Part. Diff. Eq
Resolution of the Distance Ambiguity for Galactic HII Regions
Creators: name: Anderson, L. D.
name: Bania, T. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We resolve the kinematic distance ambiguity for 266 inner Galaxy HII regions out of a sample of 291 using existing HI and 13CO sky surveys. Our sample contains all HII regions with measured radio recombination line (RRL) emission over the extent of the 13CO Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey (18 deg, < l < 55 deg. and |b| < 1) and contains ultra compact, compact, and diffuse HII regions. We use two methods for resolving the distance ambiguity for each HII region: HI emission/absorption (HIEA) and HI self-absorption (HISA). We find that the HIEA and HISA methods can resolve the distance ambiguity for 72% and 87% of our sample, respectively. When projected onto the Galactic plane, this large sample appears to reveal aspects of Galactic structure, with spiral arm-like features at Galactocentric radii of 4.5 and 6 kpc, and a lack of HII regions within 3.5 kpc of the Galactic center. Our HII regions are approximately in the ratio of 2 to 1 for far verses near distances. The ratio of far to near distances for ultra-compact HII regions is 2.2 to 1. Compact HII regions are preferentially at the near distance; their ratio of far to near distances is 1.6 to 1. Diffuse HII regions are preferentially at the far distance; their ratio of far to near distances is 3.8 to 1. This implies that the distinction between ultra compact and compact HII regions is due largely to distance, and that the large angular size of diffuse HII regions is not due solely to proximity to the Sun.
description: Accepted to ApJ
An historical commentary on Cassius Dio’s Roman history, Book 59 (Gaius Caligula)
Creators: name: Humphrey, John William
Publisher: name: University of British Columbia
Year: 2010

description: The reign of the Emperor Gaius was a period of considerable significance in the history of the Roman world. The Augustan Principate had endured virtually unchanged for three generations, and for most of that time the myth of a regenerated Republic was maintained, despite the widespread suspicion and even fear that had clouded the last years of Tiberius' reign. Gaius' accession was greeted as the beginning of a new age, a return to the glory of the reign of Augustus. Yet by the time of his violent murder only four years later, the mood of the people had, according to our sources, changed completely: Gaius in the meantime had become an oriental monarch who delighted in debauchery, murder, and wasteful extravagance. The purpose of this study of Gaius' reign is to test the validity of those traditional charges levelled against the Emperor by hostile sources. Any examination of this period of Roman history is hampered by the loss of the relevant books of Tacitus' "Annals", a loss that makes even more important a critical analysis of the surviving accounts, particularly the chronological narrative of Cassius Dio. Augmented by the contemporary treatises of Seneca and Philo, and by the later works of Josephus and Suetonius, Dio's version of the events from A.D. 37 to 41 has been responsible for the perpetuation of the common tradition concerning Gaius. In this commentary on Book 59 of Dio's history--including a study of its similarity to and divergence from other accounts, its generalizations and anachronisms, and its indebtedness to Dio's own experiences as a senator in the later Empire--I have attempted a rational reconstruction of Gaius' Principate free from the prejudices that have coloured its interpretation until recent years. The resulting picture of the Emperor is far different from that painted by our sources, whose own evidence can frequently be used to disprove their own interpretations. Such topics as his administration of the provinces, his campaigns in Germany and Gaul, his fiscal policy, and his behaviour in private and public are shown to be not immoderate but rather balanced and sensible, if subject to a certain immature rashness. Yet by seeing the Principate for what it really was--a monarchy based on military power, in the tradition of the eastern kingdoms of Alexander and his successors — and (after A.D. 39) by openly displaying his contempt for outmoded republican institutions, Gaius damned himself in the eyes of his biographers. His claim to divinity, prompted by the obsequiousness of his courtiers, was to revolt those Romans who still believed the violent propaganda used by Octavian against Antony; and his disregard of the Senate, however justified it may have been, was to prompt our aristocratic sources to consider him in the same light as Nero, Domitian, and Commodus.
Directed d-mer diffusion describing Kardar-Parisi-Zhang type of surface growth
Creators: name: Odor, Geza
name: Liedke, Bartosz
name: Heinig, Karl-Heinz
Publisher: name: arXiv
Year: 2009
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Materials Science (cond-mat.mtrl-sci)
subject: High Energy Physics - Lattice (hep-lat)
subject: Cellular Automata and Lattice Gases (nlin.CG)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We show that d+1-dimensional surface growth models can be mapped onto driven lattice gases of d-mers. The continuous surface growth corresponds to one dimensional drift of d-mers perpendicular to the (d-1)-dimensional "plane" spanned by the d-mers. This facilitates efficient, bit-coded algorithms with generalized Kawasaki dynamics of spins. Our simulations in d=2,3,4,5 dimensions provide scaling exponent estimates on much larger system sizes and simulations times published so far, where the effective growth exponent exhibits an increase. We provide evidence for the agreement with field theoretical predictions of the Kardar-Parisi-Zhang universality class and numerical results. We show that the (2+1)-dimensional exponents conciliate with the values suggested by Lassig within error margin, for the largest system sizes studied here, but we can't support his predictions for (3+1)d numerically.
description: Revised version, to appear in PRE. 7 pages, 4 figures, 1 Table
Flux Compactifications, Gauge Algebras and De Sitter
Creators: name: Dibitetto, Giuseppe
name: Linares, Roman
name: Roest, Diederik
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The introduction of (non-)geometric fluxes allows for N=1 moduli stabilisation in a De Sitter vacuum. The aim of this letter is to assess to what extent this is true in N=4 compactifications. First we identify the correct gauge algebra in terms of gauge and (non-)geometric fluxes. We then show that this algebra does not lead to any of the known gaugings with De Sitter solutions. In particular, the gaugings that one obtains from flux compactifications involve non-semi-simple algebras, while the known gaugings with De Sitter solutions consist of direct products of (semi-)simple algebras.
description: 8 pages. v2: footnote and refs added, published version
Singular Manakov Flows and Geodesic Flows on Homogeneous Spaces
Creators: name: Dragovic, Vladimir
name: Gajic, Borislav
name: Jovanovic, Bozidar
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 70H06, 53D25, 37J35

description: We prove complete integrability of the Manakov-type SO(n)-invariant geodesic flows on homogeneous spaces $SO(n)/SO(k_1)\times...\times SO(k_r)$, for any choice of $k_1,...,k_r$, $k_1+...+k_r\le n$. In particular, a new proof of the integrability of a Manakov symmetric rigid body motion around a fixed point is presented. Also, the proof of integrability of the SO(n)-invariant Einstein metrics on $SO(k_1+k_2+k_3)/SO(k_1)\times SO(k_2)\times SO(k_3)$ and on the Stiefel manifolds $V(n,k)=SO(n)/SO(k)$ is given.
description: 17 pages, minor changes
On the Numerical Evaluation of Distributions in Random Matrix Theory: A Review
Creators: name: Bornemann, Folkmar
Publisher: name: arXiv
Year: 2009
Subjects: subject: Probability (math.PR)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 15A52, 65R20, 33E17, 47G10

description: In this paper we review and compare the numerical evaluation of those probability distributions in random matrix theory that are analytically represented in terms of Painlevé transcendents or Fredholm determinants. Concrete examples for the Gaussian and Laguerre (Wishart) beta-ensembles and their various scaling limits are discussed. We argue that the numerical approximation of Fredholm determinants is the conceptually more simple and efficient of the two approaches, easily generalized to the computation of joint probabilities and correlations. Having the means for extensive numerical explorations at hand, we discovered new and surprising determinantal formulae for the k-th largest (or smallest) level in the edge scaling limits of the Orthogonal and Symplectic Ensembles; formulae that in turn led to improved numerical evaluations. The paper comes with a toolbox of Matlab functions that facilitates further mathematical experiments by the reader.
description: Version 5 has updated references; 51 pages, 8 figures, 10 tables; to appear in Markov Process. Related Fields
A note on hyperbolic leaves and wild laminations of rational functions
Creators: name: Kahn, Jeremy
name: Lyubich, Mikhail
name: Rempe, Lasse
Publisher: name: arXiv
Year: 2008
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We study the affine orbifold laminations that were constructed by Lyubich and Minsky. An important question left open in their construction is whether these laminations are always locally compact. We show that this is not the case. The counterexample we construct has the property that the regular leaf space contains (many) hyperbolic leaves that intersect the Julia set; whether this can happen is itself a question raised by Lyubich and Minsky.
description: 11 pages