cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Attosecond pulse formation in the "water window" range by optically dressed hydrogen-like plasma-based C5+ X-ray laser
Creators: name: Antonov, V. A.
name: Khairulin, I. R.
name: Kocharovskaya, Olga
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In this paper, we present the analytical theory of attosecond pulse formation via optical modulation of an active medium of the hydrogen-like C5+ plasma-based X-ray laser at 3.4 nm wavelength in the "water window" range, taking into account a variation of the population inversion caused by radiative decay of the upper lasing states. We derive an analytical solution for the X-ray field amplified by an X-ray laser with time-dependent population inversion, which is simultaneously irradiated by a strong optical laser field, and use it to find the optimal conditions for the attosecond pulse formation from a narrowband seeding X-ray field. We show that the shape of pulses can be improved at the cost of reduced pulse peak intensity (i) via external attenuation of the resonant spectral component of the amplified X-ray field or (ii) by using a resonantly absorbing medium (the active medium of the X-ray laser after the change of sign of the population inversion) for the pulse formation. The results of the analytical theory are in a good agreement with the numerical solutions of the Maxwell-Bloch equations which account for the nonlinearity, as well as the amplified spontaneous emission, of the active medium. Both analytically and numerically we show the possibility to produce a train of attosecond pulses with sub-200 as duration and the peak intensity exceeding 10^12 W/cm^2 at the carrier wavelength 3.4 nm in the "water window" range, which makes them attractive for the biological and medical applications.
description: 23 pages, 9 figures. arXiv admin note: text overlap with arXiv:1912.12458
The Nascent Red Sequence at z~2
Creators: name: Zirm, Andrew W.
name: Stanford, S. A.
name: Postman, M.
name: Overzier, R. A.
name: Blakeslee, J. P.
name: Rosati, P.
name: Kurk, J.
name: Pentericci, L.
name: Venemans, B.
name: Miley, G. K.
name: Roettgering, H. J. A.
name: Franx, M.
name: van der Wel, A.
name: Demarco, R.
name: van Breugel, W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present new constraints on the evolution of the early-type galaxy color-magnitude relation (CMR) based on deep near-infrared imaging of a galaxy protocluster at z=2.16 obtained using NICMOS on-board the Hubble Space Telescope. This field contains a spectroscopically confirmed space-overdensity of Lyman-alpha and H-alpha emitting galaxies which surrounds the powerful radio galaxy MRC 1138-262. Using these NICMOS data we identify a significant surface-overdensity (= 6.2x) of red J-H galaxies in the color-magnitude diagram (when compared with deep NICMOS imaging from the HDF-N and UDF). The optical-NIR colors of these prospective red-sequence galaxies indicate the presence of on-going dust-obscured star-formation or recently formed (
description: 8 pages, 7 figures, accepted for publication in ApJ (to appear June 1, 2008, v679n2)
Effect of imposed shear on the dynamics of a contaminated two-layer film flow down a slippery incline
Creators: name: Sani, Muhammad
name: Selvan, Siluvai Antony
name: Ghosh, Sukhendu
name: Behera, Harekrushna
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The linear instability of a surfactant-laden two-layer falling film over an inclined slippery wall is analyzed under an influence of external shear which is imposed on the top surface of the flow. The free surface of the flow as well as the interface among the fluids are contaminated by insoluble surfactants. Dynamics of both the layers are governed by the Navier--Stokes equations, and the surfactant transport equation regulates the motion of the insoluble surfactants at the interface and free surface. Instability mechanisms are compared by imposing the external shear along and opposite to the flow direction. A coupled Orr--Sommerfeld system of equations for the considered problem is derived using the perturbation technique and normal mode analysis. The eigenmodes corresponding to the Orr--Sommerfeld eigenvalue problem are obtained by employing the spectral collocation method. The numerical results imply that the stronger external shear destabilizes the interface mode instability. However, a stabilizing impact of the external shear on the surface mode is noticed if the shear is imposed in the flow direction, which is in contrast to the role of imposed external shear on the surface mode for a surfactant laden single layer falling film. Moreover, the impression of shear mode on the primary instability is analyzed in the high Reynolds number regime with sufficiently low inclination angle. Under such configuration, dominance of the shear mode over the surface mode is observed due to the weaker impact of the gravitation force on the surface instability. The shear mode can also be stabilized by applying the external shear in the counter direction of the streamwise flow. Conclusively, the extra imposed shear on the stratified two-layer falling film plays an active role to control the attitude of the instabilities.
Harmonic QPOs and Thick Accretion Disk Oscillations in BL Lac Object AO 0235+164
Creators: name: Liu, F. K.
name: Zhao, G.
name: Wu, Xue-Bing
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Periodic outbursts are observed in many AGNs and usually explained with a supermassive black hole binary (SMBHB) scenario. However, multiple periods are observed in some AGNs and cannot be explained with it. Here we analyze the periodicity of the radio light curves of AO 0235+164 at multi-frequencies and report the discovery of six QPOs in integer ratio 1:2:3:4:5:6 of QPO frequencies, of which the second with period $P_2 = (5.46 \pm 0.47) {\rm yr}$ is the strongest. We fit the radio light curves and show that the initial phases of six QPOs have zero or $π$ differences relative to each other. We suggest a harmonic relationship of QPOs. The centroid frequency, relative strength, harmonic relationship and relative initial phases of QPOs are independent of radio frequency. The harmonic QPOs are likely due to the quasi-periodic injection of plasma from an oscillating accretion disk into the jet. We estimate the supermassive black hole mass $M_{\rm BH} \simeq (4.72\pm 2.04) \times 10^8 M_\odot$ and the accretion rate $\dot{m}\simeq 0.007$. With the knowledge of accretion disk, it implies that the inner region of accretion disk of AO 0235+164 is a radiatively inefficient accretion flow. The oscillation accretion is due to the p-mode oscillation of the thick disk probably excited by a SMBHB. The theoretical predications of fundamental oscillation frequency and the harmonics are well consistent with the observations. Harmonic QPOs would be absent when the thick disk becomes geometrically thin due to the increase of accretion rate. We discuss the observations of AO 0235+164 basing on the SMBHB-thick disk oscillation scenario.
description: 40 pages, 10 figures, 1 table; accepted for publication in ApJ
Chandra Observations of the Highest Redshift Quasars from the Sloan Digital Sky Survey
Creators: name: Shemmer, Ohad
name: Brandt, W. N.
name: Schneider, Donald P.
name: Fan, Xiaohui
name: Strauss, Michael A.
name: Diamond-Stanic, Aleksandar M.
name: Richards, Gordon T.
name: Anderson, Scott F.
name: Gunn, James E.
name: Brinkmann, Jon
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present new Chandra observations of 21 z>4 quasars, including 11 sources at z>5. These observations double the number of X-ray detected quasars at z>5, allowing investigation of the X-ray spectral properties of a substantial sample of quasars at the dawn of the modern Universe. By jointly fitting the spectra of 15 z>5 radio-quiet quasars (RQQs), including sources from the Chandra archive, with a total of 185 photons, we find a mean X-ray power-law photon index of Gamma=1.95^{+0.30}_{-0.26}, and a mean neutral intrinsic absorption column density of N_H5 RQQs, excluding broad absorption line quasars, is alpha_ox=-1.69+/-0.03, which is consistent with the value predicted from the observed relationship between alpha_ox and ultraviolet luminosity. Four of the sources in our sample are members of the rare class of weak emission-line quasars, and we detect two of them in X-rays. We discuss the implications our X-ray observations have for the nature of these mysterious sources and, in particular, whether their weak-line spectra are a consequence of continuum boosting or a deficit of high-ionization line emitting gas.
description: 15 pages (emulateapj), 8 figures. Accepted by ApJ
Surgery diagrams for horizontal contact structures
Creators: name: Ozbagci, Burak
Publisher: name: arXiv
Year: 2006
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 57R17

description: We describe Legendrian surgery diagrams for some horizontal contact structures on non-positive plumbing trees of oriented circle bundles over spheres with negative Euler numbers. As an application we determine Milnor fillable contact structures on some Milnor fillable 3-manifolds.
description: 13 pages, 14 figures
Post-translational regulation of Prostate Derived Ets factor (PDEF)
Creators: name: Chisholm, Cristine Louise
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Biology, Genetics (0369)
Biology, Molecular (0307)
Biology, General (0306)
Phosphorylation
prostate
Ets
ubiquitination
Protein Kinase CK2

description: Prostate Derived Ets Factor (PDEF) is an Ets transcription factor expressed in prostate epithelium, yet the role of the protein is poorly delineated and likely context-dependent. PDEF interacts with the tumor suppressor NKX3.1, and this interaction abolishes the ability of PDEF to activate Prostate-Specific Antigen (PSA). In an effort to elucidate the biochemical regulation of PDEF, the effects of post-translational modifications were examined. Potential phosphorylation sites in PDEF for Protein Kinase CK2 were revealed by in silico analysis. Inhibition of CK2 activity with apigenin, 4,5,6,7-tetrabromo-benzimidazole (TBB) and siRNA to CK2? significantly reduced steady-state levels of PDEF in LNCaP cells and this effect was reversed by inhibiting the 26S proteasome. Mass spectrometry analysis revealed that CK2 phosphorylates PDEF at Threonine 144, Serine 151 and Serine 187 in vitro. These studies suggest that CK2 exerts a significant effect on the stability of PDEF in prostate cancer cells. The ability of the E3 ubiquitin ligases Praja1 and TOPORS to regulate PDEF was investigated. Praja1 and TOPORS ubiquitinate PDEF in vitro, and the overexpression of TOPORS reduces the half-life of PDEF. These findings are significant in light of the fact that compounds designed to inhibit components of the ubiquitin proteasome system in order to maintain the stability of tumor suppressors are being developed as cancer therapies. The biological consequences of reduced PDEF were investigated in prostate cancer cells, and it was shown that prostate cancer cells treated with PDEF siRNA exhibit dramatic changes in the prostate tumor suppressor NKX3.1, and in specific genes controlling epithelial mesenchymal transition (EMT). The relationship between PDEF and NKX3.1 is relevant to prostate cancer given that NKX3.1 is a critical tumor suppressor and potential therapeutic target, and that restoration of NKX3.1 in prostate cancer cells slows cell growth in vivo. The data reported here identify an important regulatory pathway that stabilizes the steady state level of PDEF, and identifies novel PDEF regulatory targets that are directly relevant to prostate cancer initiation and progression. These studies have illuminated novel points of therapeutic intervention in prostate cancer that may be exploited in the future to develop new treatments for this disease.
Entropy and information flow in quantum systems strongly coupled to baths
Creators: name: Seshadri, Nikhil
name: Galperin, Michael
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Considering von Neumann expression for reduced density matrix as thermodynamic entropy of a system strongly coupled to baths, we use nonequilibrium Green's function (NEGF) techniques to derive bath and energy resolved expressions for entropy, entropy production, and information flows. The consideration is consistent with dynamic (quantum transport) description and expressions reduce to expected forms in limiting cases of weak coupling or steady-state. Formulation of the flows in terms of only system degrees freedom is convenient for simulation of thermodynamic characteristics of open nonequilibrium quantum systems. We utilize standard NEGF for derivations in noninteracting systems, Hubbard NEGF is used for interacting systems. Theoretical derivations are illustrated with numerical simulations within generic junction models.
description: 11 pages, 4 figures
Black Holes and Loose Connections in The Global Urban Network.
Creators: name: Short, John Rennie
Publisher: name: Maryland Shared Open Access Repository
Year: 2002
Subjects: Connectivity
Globalization
Cities
World
Populations

description: This paper introduces the concept of black holes and loose connections in the global urban hierarchy. Black holes are defined as large cities, with a population of over 3 million that are not classified as world cities. The paper draws upon a classification that uses advanced producer services as an indicator of world city status. Large, non-world cities are identified and provisional ideas about explaining their position are outlined. Connectivity and population data are used in a simple regression analysis to identify loose connections: cities whose connectivity is less than that predicted by their population.
Evidence of strong relationship between hemispheric asymmetry in solar coronal rotation and solar activity during solar cycle 24
Creators: name: Sharma, Jaidev
name: Malik, Anil K
name: Kumar, Brajesh
name: Vats, Hari Om
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In this article, we report an evidence of very high and statistically significant relationship between hemispheric asymmetry in solar coronal rotation rate and solar activity. Our approach is based on cross correlation of hemispheric asymmetry index (AI) in rotation rate with annual solar activity indicators. To obtain hemispheric asymmetry in solar rotation rate, we use solar full disc (SFD) images at 30.4 nm, 19.5 nm, and 28.4 nm wavelengths for 24th Solar Cycle i.e., for the period from 2008 to 2018, as recorded by the Solar Terrestrial Relations Observatory (STEREO) space mission. Our analysis shows that hemispheric asymmetry in rotation rate is high during the solar maxima from 2011 to 2014. On the other hand, hemispheric asymmetry drops gradually on both sides (i.e., from 2008 to 2011 and from 2014 to 2018). The results show that asymmetry index (AI) leads sunspot numbers by ~1.56 years. This gives a clear indication that hemispheric asymmetry triggers the formation of sunspots working together with the differential rotation of the Sun.
description: 6 pages, 3 figures, Accepted for publication in MNRAS
Evolution of the 21 cm signal throughout cosmic history
Creators: name: Pritchard, Jonathan R.
name: Loeb, Abraham
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The potential use of the redshifted 21 cm line from neutral hydrogen for probing the epoch of reionization is motivating the construction of several low-frequency interferometers. There is also much interest in the possibility of constraining the initial conditions from inflation and the nature of the dark matter and dark energy by probing the power-spectrum of density perturbations in three dimensions and on smaller scales than probed by the microwave background anisotropies. Theoretical understanding of the 21 cm signal has been fragmented into different regimes of physical interest. In this paper, we make the first attempt to describe the full redshift evolution of the 21 cm signal between 0 25 before the first galaxies had formed, or to z < 6 when the residual pockets of hydrogen trace large scale structure.
description: 15 pages, 11 figures, submitted to PRD
Building an Effective International Community of Inquiry for EFL Professionals in an Asynchronous Online Discussion Board
Creators: name: Shin, Joan Kang
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Education, Teacher Training (0530)
Education, Technology (0710)
Education, Bilingual and Multicultural (0282)
international community of inquiry
asynchronous discussion board
cognitive, social, and teaching presence
EFL teacher education
inclusive pedagogy
online teacher education

description: With the capability of new Internet technology, use of online course management systems like Blackboard can facilitate the creation of international communities of professionals through computer-mediated communication (CMC). This study investigated what made an effective online learning environment for over 60 English teaching professionals from 29 different countries in North Africa, the Middle East, Central Asia, and Southeast Asia using the community of inquiry model by Garrison, Anderson, and Archer (2000) as its framework for analysis. In the community of inquiry model, successful online learning experiences take place at the intersection of teaching, social, and cognitive presence. The study used teaching presence indicators developed by Anderson, Rourke, Garrison, and Archer (2001), the researcher's modified version of social presence indicators by Rourke, Anderson, Garrison, and Archer (2001), and the practical inquiry model that operationalized cognitive presence by Garrison, Anderson, and Archer (2001). This qualitative study utilized a concurrent nested approach to compare two implementations of the same online teacher training course in 2004 and 2005. The comparison of teaching, social, and cognitive presence between one class in fall 2004 and two classes in fall 2005 focused on the use of three specific instructional strategies: word limits per message, starter-wrapper roles (Hara, Bonk, and Angeli, 2000), and instructor modeling. Analysis revealed that using these instructional strategies to change teaching presence caused some increase in social and cognitive presence in one of the fall 2005 classes, but not in the other. Exceptions related to group cohesion through shared language, culture, and religion and obstacles to Internet access are discussed as possible explanations. In addition, this study examines the role of cultural inclusivity for building an effective community of inquiry among international professionals. Furthermore, it questions the importance of reaching higher phases of the practical inquiry model (Garrison et al., 2001) to build an effective community of inquiry among teachers for whom social bonds may be of greater importance. The results of this study support and extend Garrison et al.'s (2000) community of inquiry model through its application to an international online learning environment that brought together geographically distributed English teaching professionals.
Strong Infrared Emission from the Extrasolar Planet HD189733b
Creators: name: Deming, Drake
name: Harrington, Joseph
name: Seager, Sara
name: Richardson, L. Jeremy
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report detection of strong infrared thermal emission from the nearby (d=19 pc) transiting extrasolar planet HD189733b, by measuring the flux decrement during its prominent secondary eclipse. A 6-hour photometric sequence using Spitzer's infrared spectrograph in peak-up imaging mode at 16-microns shows the secondary eclipse depth to be 0.551 +/-0.030%, with accuracy limited by instrumental baseline uncertainties, but with 32-sigma precision (0.017%) on the detection. The 16-micron brightness temperature of this planet (1117+/-42K) is very similar to the Spitzer detections of TrES-1 and HD209458b, but the observed planetary flux (660 micro-Jy) is an order of magnitude greater. This large signal will allow a detailed characterization of this planet in the infrared. Our photometry has sufficient signal-to-noise (~400 per point) to motivate a search for structure in the ingress/egress portions of the eclipse curve, caused by putative thermal structure on the disk of the planet. We show that by binning our 6-second sampling down to 6-minute resolution, we detect the modulation in the intensity derivative during ingress/egress due to the overall shape of the planet, but our sensitivity is not yet sufficient to distinguish between realistic models of the temperature distribution across the planet's disk. We point out the potential for extending Spitzer secondary eclipse detections down to the regime of transiting hot Neptunes, if such systems are discovered among nearby lower main sequence stars.
description: 14 pages, 3 figures, accepted for ApJ
LOFAR Detection of a Low-Power Radio Halo in the Galaxy Cluster Abell 990
Creators: name: Hoang, N. D.
name: Shimwell, T. W.
name: Osinga, E.
name: Bonafede, A.
name: Brüggen, M.
name: Botteon, A.
name: Brunetti, G.
name: Cassano, R.
name: Cuciti, V.
name: Drabent, A.
name: Jones, C.
name: Röttgering, H. J. A.
name: van Weeren, R. J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Radio halos are extended ($\sim{\rm Mpc}$), steep-spectrum sources found in the central region of dynamically disturbed clusters of galaxies. Only a handful of radio halos have been reported to reside in galaxy clusters with a mass $M_{500}\lesssim5\times10^{14}\,M_\odot$. In this paper we present a LOFAR 144 MHz detection of a radio halo in the galaxy cluster Abell 990 with a mass of $M_{500}=(4.9\pm0.3)\times10^{14}\,M_\odot$. The halo has a projected size of $\sim$700$\,{\rm kpc}$ and a flux density of $20.2\pm2.2\,{\rm mJy}$ or a radio power of $1.2\pm0.1\times10^{24}\,{\rm W\,Hz}^{-1}$ at the cluster redshift ($z=0.144$) which makes it one of the two halos with the lowest radio power detected to date. Our analysis of the emission from the cluster with Chandra archival data using dynamical indicators shows that the cluster is not undergoing a major merger but is a slightly disturbed system with a mean temperature of $5\,{\rm keV}$. The low X-ray luminosity of $L_{X}=(3.66\pm0.08)\times10^{44}\,{\rm ergs\,s}^{-1}$ in the 0.1--2.4 keV band implies that the cluster is one of the least luminous systems known to host a radio halo. Our detection of the radio halo in Abell 990 opens the possibility of detecting many more halos in poorly-explored less-massive clusters with low-frequency telescopes such as LOFAR, MWA (Phase II) and uGMRT.
An Exploration of Identity Development and Culturally Relevant Teaching Practices Among African American Elementary Pre-Service Teachers in Urban Communities
Creators: name: Ashby Bey, Juanita Denee
Publisher: name: Maryland Shared Open Access Repository
Year: 2007
Subjects: Education, Teacher Training (0530)
Education, Elementary (0524)
Culturally Relevant Teaching Practices
Intervention Models

description: African Americans living in urban communities are subjected to many disparities including racial discrimination and cultural discontinuities that manifest in public school classrooms. African American students continue to struggle academically and are less likely to attend college, which maintains their impoverished status. This study was designed to investigate how teacher education programs could help improve the academic status of urban African American students. ; The purpose of this study was to explore and document the results of integrating theoretical and pedagogical knowledge related to identity development and culturally relevant teaching into a teacher education program as an intervention method to more effectively prepare pre-service teachers to teach urban African American students. ; This study utilized a mixed method concurrent nested approach. Case study methodology and ethnographic components were used to collect data for this project. Quantitative data collection methods included the use of CRIS to collect identity data and the CRTI to collect data on culturally relevant teaching practices. Qualitative data were collected using reflective journals, field notes, observations, interviews, and debriefing sessions. ; Results of the study indicated that pre-service teachers believed that the intervention activities were beneficial inclusions in their academic program.  The sessions helped the African American pre-service teachers understand the relationship between their oppressive experiences and their identity. All pre-service teachers experienced some change in their identity and all pre-service teachers applied some culturally relevant teaching strategies; however, they require additional preparation to apply notions of political expression, sociopolitical critique, and community responsibility. Data also indicated that the pre-service teachers realized that their role as teachers included helping African American students transform their lives. Additionally, there was consistent evidence that suggested that pre-service teachers began to develop a critical consciousness and began to engage in critical action. A very important finding of this research was the discovery of the lack of knowledge that pre-service teachers have about the history of the Diaspora, including African American history.
From World Cities to Globalizing Cities
Creators: name: Short, John Rennie
Publisher: name: Maryland Shared Open Access Repository
Year: 2001
Subjects: Globalization
Cities
World
Economic

description: In this paper we argue that the focus on world cities has narrowed our understanding of the globalization/city relationship and ignores the processes of globalization occurring in almost all cities. By developing the notion of gateway cities, this paper seeks to widen globalization research. We provide a list of topics that can be explored using this gateway city notion, including reglobalization, rescaling, representation, spectacle and urban regimes.
Tight-Binding Model and Electronic Property of Dirac Nodal Line in Single-Component Molecular Conductor [Pt(dmdt)$_{2}$]
Creators: name: Kawamura, Taiki
name: Ohki, Daigo
name: Zhou, Biao
name: Kobayashi, Akiko
name: Kobayashi, Akito
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Motivated by the recent discovery of Dirac nodal line in the single-component molecular conductor [Pt(dmdt)$_{2}$], we propose a three-orbital tight-binding model based on the Wannier fitting of the first-principles calculation, and address the problems of edge states, topological properties and magnetic susceptibility. We find that logarithmic peaks of the local density of states emerge near the Fermi energy, owing to pseudo-one-dimensional edge states that appear between the Dirac nodal lines. Magnetic susceptibility calculated in our model can explain the experimental result at a high temperature. In the presence of a realistic spin-orbit coupling, we show that [Pt(dmdt)$_{2}$] is a topological nodal line semimetal with isolated electron and hole pockets.
Dieter, Theodor (Hrsg.): Lutherische Identität/Lutheran Identity
Creators: name: Hammes, Verena
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 69 Nr. 1 (2020): Ökumenische Rundschau, Band 69, Heft 1
A Case Study of International ESL Learners' Perceptions of Technology Use in English Language Learning
Creators: name: Rashed, Doaa
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Education, Technology (0710)
Education, Bilingual and Multicultural (0828)
Computer-assisted Language Learning
CALL
Technology integration
English as a Second Language
ESL
Intensive English Programs
IEP

description: Research in English as a Second Language (ESL) learners' perceptions of integrating technology in language learning is still relatively new. Most studies focused on the integration of one technology application in language instruction. In this study, the author examines the perceptions of six ESL international students in the English Language Center at UMBC about their experience in computer-assisted language learning (CALL). The study implements a variety of technology applications. A case study research methodology was used. Individual case studies and cross-case study techniques were employed. Data collection involved a survey, initial and final interviews, observation, and researcher's reflective journal. The analysis of the findings was organized in four major categories: learners' statements about their perceptions, learners' behaviors while interacting with technology tools, and learners' concerns about limitations of technology integration, and researcher's perceptions of the limitations. The findings revealed learners' positive perceptions of technology applications as language learning tools, with a deep concern for the communicative, collaborative and interactive nature of the applications. The use of technology in language learning was always supported by the presence of the language instructor as a coordinator and facilitator of the learning experience. Trust in the instructor's ability to connect the technology learning tools with the learning goals was deeply valued. Through this experience, the researcher, who was also the instructor for the course, learned the importance of class instruction and technical support for technology use in the language classroom.
Supporting Information from Removal of bisphenol A from aqueous media using a highly selective adsorbent of hybridization cyclodextrin with magnetic molecularly imprinted polymer
Creators: name: S. Mamman
name: F. B. M. Suah
name: M. Raaov
name: F. S. Mehamod
name: S. Asman
name: N. N. M. Zain
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Environmental Chemistry
subject: Environmental Science
subject: 30399 Macromolecular and Materials Chemistry not elsewhere classified
subject: FOS: Chemical sciences

description: In this study, a unique magnetic molecularly imprinted polymer (MMIP) adsorbent towards bisphenol A (BPA) as a template molecule was developed by bulk polymerization using β-cyclodextrin (β-CD1H NMR spectroscopy was used to characterize the MAA–βCD and BPA–MAA–βCD complex. Several parameters influencing the adsorption efficiency of BPA such as adsorbent dosage, pH of sample solution, contact time, initial concentrations and temperature as well as selectivity and reusability study have been evaluated. MMIP MAA–βCD showed significantly higher removal efficiency and selective binding capacity towards BPA compared to MMIP MAA due to its unique morphology with the presence of β-CD. The kinetics data can be well described by the pseudo second-order kinetic and Freundlich isotherm and Halsey models best fitted the isotherm data. The thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process. Therefore, MMIP based on the hybrid monomer of MAA–βCD shows a good potential of new monomer in molecularly imprinted polymers preparation and can be used as an effective adsorbent for the removal of BPA from aqueous solutions.
Soft Gamma Repeaters and Short Gamma Ray Bursts: making magnetars from WD-WD mergers
Creators: name: Chapman, R.
name: Levan, A. J.
name: Wynn, G. A.
name: Davies, M. B.
name: King, A. R.
name: Priddey, R. S.
name: Tanvir, N. R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent progress on the nature of short duration Gamma Ray Bursts (GRBs) has shown that a fraction of them originate in the local universe. These systems may well be the result of giant flares from Soft Gamma Repeaters (SGRs) believed to be magnetars (neutron stars with extremely large magnetic fields >= 10^14 G). If these magnetars are formed via the core collapse of massive stars, then it would be expected that the bursts should originate from predominantly young stellar populations. However, correlating the positions of BATSE short bursts with structure in the local universe reveals a correlation with all galaxy types, including those with little or no ongoing star formation. This is a natural outcome if, in addition to magnetars forming via the core collapse of massive stars, they also form via Accretion Induced Collapse following the merger of two white dwarfs, one of which is magnetic. We investigate this possibility and find that the rate of magnetar production via WD-WD mergers in the Milky Way is comparable to the rate of production via core collapse. However, while the rate of magnetar production by core collapse is proportional to the star formation rate, the rate of production via WD-WD mergers (which have long lifetimes) is proportional to the stellar mass density, which is concentrated in early-type systems. Therefore magnetars produced via WD-WD mergers may produce SGR giant flares which can be identified with early type galaxies. We also comment on the possibility that this mechanism could produce a fraction of the observed short duration GRB population at low redshift.
description: 4 pages, 3 figures. Included in Proceedings of EuroWD06 to be published in Conference Series of the Astronomical Society of the Pacific
A Case Study of Bilingual Latino Middle School Students' Attitudes Towards Language, School and Learning
Creators: name: Fishbein, Jacob Alan
Publisher: name: Maryland Shared Open Access Repository
Year: 2009
Subjects: Attitude
Bilingual
Biliteracy
Language
Latino
Middle School

description: This study explores the attitudes of five, sixth-grade, bilingual Latino students at an urban, public, charter middle school. The participants in this study took part in an after school, bilingual English/Spanish reading program over the course of ten weeks. The research was conducted using a case study methodology. Data was collected using semi-structured interviews with the participants and their parents, observations of the after school program, and informal conversations with participants' mainstream classroom teachers. By exploring these students' attitudes, educators and policy makers can gain better insight into how to address the linguistic and cultural needs of bilingual Latino learners. The findings of this study suggest that, although having generally positive attitudes towards school and learning, the participants occasionally felt disconnected from class content. The findings also suggest that these students' levels of engagement could be increased by providing them with bilingual literature that relates to their specific linguistic and cultural backgrounds.
No relation for Wigner's friend
Creators: name: Castellani, Leonardo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: History and Philosophy of Physics (physics.hist-ph)
subject: FOS: Physical sciences

description: We argue that Wigner's friend thought experiment does not support observer dependence of quantum states. An analysis in terms of history vectors suggests that quantum collapse is to be understood as collapse of histories rather than collapse of states.
description: 7 pages, 1 figure
Getting Away With It: The Changing Geography of The Global Superich.
Creators: name: Short, John Rennie
Publisher: name: Maryland Shared Open Access Repository
Year: 2002
Subjects: Transnational
Global
Capitalism
Consumption
Class Flows

description: Political geographers have repeatedly alerted to the forms of social inequality perpetuated by a capitalism that is increasingly global in scope. In so doing, they have often highlighted the existence of marginalized populations living on or below the poverty line, suggesting policies that might alleviate the conditions of these groups. In contrast, little has been written about the principal beneficiaries of global process - the super-rich who have amassed huge personal fortunes by manipulating global flows to their own advantage. Contrasting the increasingly 'fast' lifestyles of the super-rich with the lives of those who dwell in the 'slow' world, we suggest that the discrepancy between the super-rich and the rest is a major obstacle to the achievement of a more just and equitable world, that instead of studying the poor, much is to be gained by exposing the geographies of the rich. In this paper, we thus set an agenda for investigating the geographies of this elite group by highlighting the global dimensions of their lifestyles and arguing for research that takes their transnationalism seriously.
Native and forage grasses - Reservoir of new Fusarium species
Creators: name: Costa, Marileide M.
Publisher: name: Zenodo
Year: 2023

description: Talk presented at the "Special Interest Group (SIG) Symposium of the H2020-MSCA-RISE project “Mycobiomics”" of the Asian Mycological Congress 2023 (AMC2023), BEXCO, Busan, Republic of Korea, 10-13 October 2023
An investigation of in-vessel composting process control strategies
Creators: name: Fraser, Bud S.
Publisher: name: University of British Columbia
Year: 2009

description: Composting provides environmental benefits including an alternative method for organic waste disposal, as well as improving soil fertility. However poor compost quality and odour emission are often significant problems in the composting industry. Composting process control can potentially help reduce both of these problems. In spite of the recent development of a number of process control strategies, very few direct comparisons have been made between these, particularly in terms of compost quality and odour emission. To help address this need, a series of experiments was conducted to evaluate the effects of several in-vessel process control strategies on compost quality and odour emission. The strategies tested focussed on aeration control, which in turn affects temperature, oxygen, and moisture, the most important conditions for microbial activity. Fixed aeration (Beltsville method), temperature feedback (Rutgers method), oxygen feedback, and combined temperature/oxygen feedback were tested. A modified algorithm based on temperature, called linear temperature feedback, was also developed and tested. Results showed that while many quality parameters such as C:N ratio and organic matter loss were similar between process control methods, compost oxygen was maintained more consistently using oxygen feedback or linear temperature feedback methods; these methods may also provide greater nitrification and lower phytotoxicity. Linear temperature feedback is preferable to oxygen feedback in that it does not require oxygen sensors to operate. Odorous gas (including ammonia) mass emission rates were typically found to increase with higher aeration rates, such as those used to limit temperature, though the gas concentration was lower. For maximum retention of nitrogen, adequate supply of readily biodegradable carbon in the feedstock is vital.
An improved set of electron-THFA cross sections refined through a neural network-based analysis of swarm data
Creators: name: Stokes, Peter W.
name: Foster, Sean P.
name: Casey, Madalyn J. E.
name: Cocks, Daniel G.
name: González-Magaña, Olmo
name: de Urquijo, Jaime
name: García, Gustavo
name: Brunger, Michael J.
name: White, Ronald D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We review experimental and theoretical cross sections for electron transport in $α$-tetrahydrofurfuryl alcohol (THFA) and, in doing so, propose a plausible complete set. To assess the accuracy and self-consistency of our proposed set, we use the pulsed-Townsend technique to measure drift velocities, longitudinal diffusion coefficients and effective Townsend first ionisation coefficients for electron swarms in admixtures of THFA in argon, across a range of density-reduced electric fields from 1 Td to 450 Td. These measurements are then compared to simulated values derived from our proposed set using a multi-term solution of Boltzmann's equation. We observe discrepancies between the simulation and experiment, which we attempt to address by employing a neural network model that is trained to solve the inverse swarm problem of unfolding the cross sections underpinning our experimental swarm measurements. What results from our neural network-based analysis is a refined set of electron-THFA cross sections, which we confirm is of higher consistency with our swarm measurements than that we initially proposed. We also use our data base to calculate electron transport coefficients in pure THFA, across a range of reduced electric fields from 0.001 Td to 10,000 Td.
description: 37 pages, 19 figures, submitted to The Journal of Chemical Physics
An Optimal Solution to a Resource Allocation Problem
Creators: name: Kamdem, Bruno Georges
Publisher: name: Maryland Shared Open Access Repository
Year: 2008
Subjects: Mathematics (0405)
Optimization
Allocation
Solow
KKT condition

description: to study a well known problem of resource allocation in microeconomics. We formulate the resource allocation problem as a finite-dimensional convex program under appropriate assumptions. Important properties of the constraints and objective function are discussed, which yield the existence and uniqueness of the optimal solution. The optimality conditions and KKT conditions are derived under a constraint qualification result. We then focus on a particular allocation problem for which a closed-form optimal solution is obtained. Finally, an exogenous growth model is discussed. We subsequently derive the relevant economic implications.
Supplementary Data from Removal of bisphenol A from aqueous media using a highly selective adsorbent of hybridization cyclodextrin with magnetic molecularly imprinted polymer
Creators: name: S. Mamman
name: F. B. M. Suah
name: M. Raaov
name: F. S. Mehamod
name: S. Asman
name: N. N. M. Zain
Publisher: name: The Royal Society
Year: 2021
Subjects: subject: Environmental Chemistry
subject: Environmental Science
subject: 30399 Macromolecular and Materials Chemistry not elsewhere classified
subject: FOS: Chemical sciences

description: In this study, a unique magnetic molecularly imprinted polymer (MMIP) adsorbent towards bisphenol A (BPA) as a template molecule was developed by bulk polymerization using β-cyclodextrin (β-CD1H NMR spectroscopy was used to characterize the MAA–βCD and BPA–MAA–βCD complex. Several parameters influencing the adsorption efficiency of BPA such as adsorbent dosage, pH of sample solution, contact time, initial concentrations and temperature as well as selectivity and reusability study have been evaluated. MMIP MAA–βCD showed significantly higher removal efficiency and selective binding capacity towards BPA compared to MMIP MAA due to its unique morphology with the presence of β-CD. The kinetics data can be well described by the pseudo second-order kinetic and Freundlich isotherm and Halsey models best fitted the isotherm data. The thermodynamic studies indicated that the adsorption reaction was a spontaneous and exothermic process. Therefore, MMIP based on the hybrid monomer of MAA–βCD shows a good potential of new monomer in molecularly imprinted polymers preparation and can be used as an effective adsorbent for the removal of BPA from aqueous solutions.
Wikitology: A Novel Hybrid Knowledge Base Derived from Wikipedia
Creators: name: Syed, Zareen Saba
Publisher: name: Maryland Shared Open Access Repository
Year: 2010
Subjects: Information Extraction
Information Retrieval
Knowledge Base
Semantic Web

description: World knowledge may be available in different forms such as relational databases, triple stores, link graphs, meta-data and free text. Human minds are capable of understanding and reasoning over knowledge represented in different ways and are influenced by social, contextual and environmental factors. By following a similar model, we have integrated a variety of knowledge sources in a novel way to produce a single hybrid knowledge base, Wikitology, enabling applications to better access and exploit knowledge hidden in different forms. Research projects like Cyc have resulted in the development of a complex broad coverage knowledge base however, relatively few applications have been built that really exploit it. In contrast, the design and development of the Wikitology KB has been incremental and driven and guided by a variety of applications, including document concept prediction, cross document co-reference resolution defined as a task in Automatic Content Extraction, linking entity mentions to KB entries defined as a part of TAC Knowledge Base Population Track, and interpreting tables. These use cases directly serve to evaluate the utility of the knowledge base for different applications and also demonstrate how the knowledge base could be exploited in different ways.  We have also developed an approach for automatically enriching the Wikitology KB by unsupervised discovery of ontology elements from Wikipedia article links.
Kappes, Michael / Link-Wieczorek, Ulrike / Pemsel-Maier, Sabine / Schuegraf, Oliver (Hrsg.): Basiswissen Ökumene
Creators: name: Schmidt, Markus
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 69 Nr. 1 (2020): Ökumenische Rundschau, Band 69, Heft 1
A new abundance scale for the globular cluster 47 Tuc
Creators: name: Koch, Andreas
name: McWilliam, Andrew
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present chemical abundances for O, Na, Mg, Al, Si, Ca, Ti and Fe in eight red giants and one turnoff star in the metal rich globular cluster 47 Tuc, based on spectroscopy with the MIKE high resolution spectrograph on the Magellan 6.5-m Clay telescope. A robust line by line differential abundance analysis technique, relative to the K-giant Arcturus, was used to reduce systematic errors from atmospheric and atomic parameters. Our derived mean LTE [Fe/H] of -0.76 +- 0.01 +- 0.04 dex (random and systematic error, respectively) is more metal poor by about 0.1 dex than recent literature results. The chemical element ratios in this nearby globular cluster most closely resemble those of the Galactic bulge, although there is a non-negligible overlap with the composition of thick-disk stars. We find that the [Al/Fe] and [Na/Fe] ratios coincide with the upper boundary of the trends seen in the bulge and thick disk. There is only a small intrinsic scatter in the majority of the abundance ratios, indicating that 47 Tuc is mostly a rather chemically homogeneous system.
description: Now with correct Figure 6; no other changes; 22 pages, 8 figures, accepted for publication in the AJ