cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Bounded solutions of neutral fermions with a screened Coulomb potential
Creators: name: de Castro, Antonio S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The intrinsically relativistic problem of a fermion subject to a pseudoscalar screened Coulomb plus a uniform background potential in two-dimensional space-time is mapped into a Sturm-Liouville. This mapping gives rise to an effective Morse-like potential and exact bounded solutions are found. It is shown that the uniform background potential determinates the number of bound-state solutions. The behaviour of the eigenenergies as well as of the upper and lower components of the Dirac spinor corresponding to bounded solutions is discussed in detail and some unusual results are revealed. An apparent paradox concerning the uncertainty principle is solved by recurring to the concepts of effective mass and effective Compton wavelength.
description: 15 pages, 7 figures
Deuterium enhancement in H3+ in prestellar cores
Creators: name: Vastel, Charlotte
name: Phillips, T. G.
name: Caselli, P.
name: Ceccarelli, C.
name: Pagani, L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Deuterium enhancement of monodeuterated species has been recognized for more than 30 years as a result of the chemical fractionation that results from the difference in zero point energies of deuterated and hydrogenated molecules. The key reaction is the deuteron exchange in the reaction between HD, the reservoir of deuterium in dark interstellar clouds, and the H3+ molecular ion, leading to the production of the H2D+ molecule, and the low temperature in dark interstellar clouds favors this production. Furthermore, the presence of multiply deuterated species have incited our group to proceed further and consider the subsequent reaction of H2D+ with HD, leading to D2H+ (first detected by Vastel et al. 2004), which can further react with HD to produce D3+. In prestellar cores, where CO was found to be depleted (Bacmann et al. 2003), this production should be increased, as CO would normally destroy H3+. The first model including D2H+ and D3+ (Roberts, Herbst & Millar 2003) predicted that these molecules should be as abundant as H2D+ (see contribution by H. Roberts). The first detection of the D2H+ was made possible by the recent laboratory measurement by Hirao & Amano (2003) for the frequency of the fundamental line of the para-D2H+ (see contribution by T. Amano). Here we present observations of H2D+ and D2H+ towards a sample of dark clouds and prestellar cores and show how the distribution of ortho-H2D+ (1_1,0-1_1,1) can trace the deuterium factory in prestellar cores. We also present how future instrumentation will improve our knowledge concerning the deuterium enhancement of H3+.
description: Physics, chemistry and astronomy of H3+, accepted in Phil. Trans. R. Soc. Lond. A (2006)
Ultra-shallow junction electrodes in low-loss silicon micro-ring resonators
Creators: name: Xu, Bin-Bin
name: de Boo, Gabriele G.
name: Johnson, Brett C.
name: Rančić, Miloš
name: Bedoya, Alvaro Casas
name: Morrison, Blair
name: McCallum, Jeffrey C.
name: Eggleton, Benjamin J.
name: Sellars, Matthew J.
name: Yin, Chunming
name: Rogge, Sven
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Electrodes in close proximity to an active area of a device are required for sufficient electrical control. The integration of such electrodes into optical devices can be challenging since low optical losses must be retained to realise high quality operation. Here, we demonstrate that it is possible to place a metallic shallow phosphorus doped layer in a silicon micro-ring cavity that can function at cryogenic temperatures. We verify that the shallow doping layer affects the local refractive index while inducing minimal losses with quality factors up to 10$^5$. This demonstration opens up a pathway to the integration of an electronic device, such as a single-electron transistor, into an optical circuit on the same material platform.
description: 6 figures
First cosmic shear results from the Canada-France-Hawaii Telescope Wide Synoptic Legacy Survey
Creators: name: Hoekstra, H.
name: Mellier, Y.
name: van Waerbeke, L.
name: Semboloni, E.
name: Fu, L.
name: Hudson, M. J.
name: Parker, L. C.
name: Tereno, I.
name: Benabed, K.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the first measurements of the weak gravitational lensing signal induced by the large scale mass distribution from data obtained as part of the ongoing Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The data used in this analysis are from the Wide Synoptic Survey, which aims to image ~170 square degree in five filters. We have analysed ~22 deg2 (31 pointings) of i' data spread over two of the three survey fields. These data are of excellent quality and the results bode well for the remainder of the survey: we do not detect a significant `B'-mode, suggesting that residual systematics are negligible at the current level of accuracy. Assuming a Cold Dark Matter model and marginalising over the Hubble parameter h=[0.6,0.8], the source redshift distribution and systematics, we constrain sigma_8, the amplitude of the matter power spectrum. At a fiducial matter density Omega_m=0.3 we find sigma_8=0.85+-0.06. This estimate is in excellent agreement with previous studies. Combination of our results with those from the Deep component of the CFHTLS enables us to place a constraint on a constant equation of state for the dark energy, based on cosmic shear data alone. We find that w_0
description: Submitted to ApJ
Design and analysis of electro-optic modulators based on high contrast gratings (HCGs) in AlGaN/GaN heterostructures
Creators: name: Das, Pallabi
name: Singh, Shlok Vaibhav
name: Tallur, Siddharth
Publisher: name: arXiv
Year: 2020
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Recently High Electron Mobility Transistor (HEMT) inspired III-V electro-optic modulator topologies were proposed for realizing high speed electro-optic modulators leveraging plasma dispersion effect due to the 2D Electron Gas (2DEG) present at the III-V heterostructure interface. The 2DEG is highly confined at the interface, extending to very low depths in the bulk ($\approx$10nm) and therefore has limited spatial overlap with the optical mode. In this paper, we propose a novel modulator design to boost the 2DEG-light interaction, wherein the HEMT is embedded within a high contrast grating (HCG) mirror. We present an analytical model extending the conventional HCG model to multi-layer structures and observe good agreement with rigorous coupled-wave analysis (RCWA). We explore the design space for identifying optimal device topology and present geometries that produce a change in reflectivity as large as 70% for C- and L-band wavelengths. We also present results of sensitivity analysis and observe low variation in device performance due to geometry variation arising from device fabrication imperfections. The device platforms presented here are suitable for designing high efficiency electro-optic modulators by incorporating the HEMT HCG into a Fabry-Perot cavity.
description: Semicond. Sci. Technol 2020
Yang--Baxterizations, Universal Quantum Gates and Hamiltonians
Creators: name: Zhang, Yong
name: Kauffman, Louis H.
name: Ge, Mo-Lin
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The unitary braiding operators describing topological entanglements can be viewed as universal quantum gates for quantum computation. With the help of the Brylinskis's theorem, the unitary solutions of the quantum Yang--Baxter equation can be also related to universal quantum gates. This paper derives the unitary solutions of the quantum Yang--Baxter equation via Yang--Baxterization from the solutions of the braided relation. We study Yang--Baxterizations of the non-standard and standard representations of the six-vertex model and the complete solutions of the non-vanishing eight-vertex model. We construct Hamiltonians responsible for the time-evolution of the unitary braiding operators which lead to the Schr{ö}dinger equations.
description: v1:36 pages, 3 figures, latex; v2: 35 pages, typo errors corrected and diagrams redrawn; v3: RevTex4, 24 pages, 3 .eps files; v4: latex, references updated
Quantifying the Performance of a Hybrid Pixel Detector with GaAs:Cr Sensor for Transmission Electron Microscopy
Creators: name: Paton, Kirsty A.
name: Veale, Matthew C.
name: Mu, Xiaoke
name: Allen, Christopher S.
name: Maneuski, Dzmitry
name: Kübel, Christian
name: O'Shea, Val
name: Kirkland, Angus I.
name: McGrouther, Damien
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Hybrid pixel detectors (HPDs) have been shown to be highly effective for diffraction-based and time-resolved studies in transmission electron microscopy, but their performance is limited by the fact that high-energy electrons scatter over long distances in their thick Si sensors. An advantage of HPDs compared to monolithic active pixel sensors (MAPS) is that their sensor does not need to be fabricated from Si. We have compared the performance of the Medipix3 HPD with a Si sensor and with a GaAs:Cr sensor using primary electrons in the energy range of 60 - 300keV. We describe the measurement and calculation of the detectors' modulation transfer function (MTF) and detective quantum efficiency (DQE), which show that the performance of the GaAs:Cr device is markedly superior to that of the Si device for high-energy electrons.
description: 15 pages + references, 13 figures
picFoam: An OpenFOAM based electrostatic Particle-in-Cell solver
Creators: name: Kühn, Christoph
name: Groll, Rodion
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: picFoam is a fully kinetic electrostatic Particle-in-Cell(PIC) solver, including Monte Carlo Collisions(MCC), for non-equilibrium plasma research in the open-source framework of OpenFOAM. The solver's modular design, based on the same principles used in OpenFOAM, makes it highly flexible, by allowing the user to choose different methods at run time, and extendable, by building upon templated modular classes. The implementation of the PIC method employing the finite volume method, allows it to simulate on arbitrary geometries in one to three dimensions. OpenFOAM's barycentric particle tracking is used effectively to performe charge and field weighting from the Lagrangian particle based description to the Eulerian field description and backwards without computational expensive particle searching algorithm. picFoam also includes open and general circuit boundary models for the description of real plasma devices.
Modulation of the Shubnikov-de Haas Oscillation in Unidirectional Lateral Superlattices
Creators: name: Endo, Akira
name: Iye, Yasuhiro
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The amplitude and phase of Shubnikov-de Haas oscillations have been analyzed in detail for two-dimensional electron gases subjected to a weak unidirectional periodic potential modulation. The amplitude is suppressed, accompanied by inversion of the phase, at the maximum bandwidth conditions at low magnetic fields. The suppression is gradually taken over by the enhancement with the increase of the magnetic fields. The suppression and the enhancement are attributable to the collisional and the diffusion contribution of the modulated potential to the conductivity, respectively, the former (the latter) being dominant at low (high) magnetic fields. A theoretical calculation that takes the two types of contributions into account shows semi-quantitative agreement with experimental traces.
description: 10 pages, 8 figures; typos corrected
Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
Creators: name: Sergienko, I. A.
name: Dagotto, E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: With the perovskite multiferroic RMnO3 (R = Gd, Tb, Dy) as guidance, we argue that the Dzyaloshinskii-Moriya interaction (DMI) provides the microscopic mechanism for the coexistence and strong coupling between ferroelectricity and incommensurate magnetism. We use Monte-Carlo simulations and zero temperature exact calculations to study a model incorporating the double-exchange, superexchange, Jahn-Teller and DMI terms. The phase diagram contains a multiferroic phase between A and E antiferromagnetic phases, in excellent agreement with experiments.
description: 6 pages, 5 figures
Semantic elicitation: Bare noun interpretation
Creators: name: Kipkoech, Linus
name: Bossi, Madeline
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2021
Subjects: subject: sgc

description: One .mp4 file and one .pdf file. Elicitation of mass nouns and their various interpretations (e.g. generic, existential, definite).
Superstring Theory on pp Waves with ADE Geometries
Creators: name: Abounasr, Raja
name: Belhaj, Adil
name: Rasmussen, Jorgen
name: Saidi, El Hassan
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the BMN correspondence between certain Penrose limits of type IIB superstrings on pp-wave orbifolds with $ADE$ geometries, and the set of four-dimensional $\mathcal{N}=2$ superconformal field theories constructed as quiver gauge models classified by finite $ADE$ Lie algebras and affine $\hat{ADE}$ Kac-Moody algebras. These models have 16 preserved supercharges and are based on systems of D3-branes and wrapped D5- and D7-branes. We derive explicitly the metrics of these pp-wave orbifolds and show that the BMN extension requires, in addition to D5-D5 open strings in bi-fundamental representations, D5-D7 open strings involving orientifolds with $Sp(N)$ gauge symmetry. We also give the correspondence rule between leading string states and gauge-invariant operators in the $\mathcal{N}=2$ quiver gauge models.
description: 62 pages
Mid-Rapidity Direct-Photon Production in p+p Collisions at sqrt(s) = 200 GeV
Creators: name: PHENIX Collaboration
name: Adler, S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A measurement of direct photons in p+p collisions at sqrt(s)=200 GeV is presented. A photon excess above background from pi^0 --> gamma+gamma, eta --> gamma+gamma, and other decays is observed in the transverse momentum range 5.5 < p_T < 7 GeV/c. The result is compared to a next-to-leading-order perturbative QCD calculation. Within errors, good agreement is found between the QCD calculation and the measured result.
description: 330 authors, 7 pages text, RevTeX, 2 figures, 2 tables. Submitted to Physical Review D. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.html
Validating the deep reef refugia hypothesis
Creators: name: Laverick, Jack
name: Rogers, Alex David
Publisher: name: F1000Research
Year: 2015

description: In 1996 Peter Glynn first suggested corals maybe protected from impacts when found at depth. When this is the case deeper reefs maybe able to seed recovery in the shallows by providing a source of recruits. This is known as the deep reef refugia hypothesis while the deeper portions of coral reefs (30-100m deep) are now termed Mesophotic Coral Ecosystems. Tropical coral reef biologists typically consider shallow reefs above 20m due to limits of recreational SCUBA techniques. Missions employing ROVs and submersibles tend to overshoot the photic zone.

This poster reports a recent Oxford university expedition to Honduras titled ‘Thinking Deep’ which used 6 closed circuit rebreather divers to gather data in person from mesophotic ecosystems down to 85m. The questions being answered by this expedition for my PhD address 3 key assumptions of the deep reef refugia hypothesis.

1) The same species are present shallow and deep.

Benthic video transects have been collected to allow the identification of a specialist mesophotic community.

2) Mesophotic corals are reproductively active.

Spawning observations were conducted and there are future plans for population genetics.

3) Mesophotic individuals are capable of adapting to existence in the shallows.

Aquaria trials and fixed samples brought back to the UK aim to reveal how mesophotic corals are adapted to surviving in a low light environment.

Interests for future collaborations are also detailed.
Analysis of Energy Consumption in a Precision Beekeeping System
Creators: name: Hadjur, Hugo
name: Ammar, Doreid
name: Lefèvre, Laurent
Publisher: name: arXiv
Year: 2020
Subjects: subject: Hardware Architecture (cs.AR)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Honey bees have been domesticated by humans for several thousand years and mainly provide honey and pollination, which is fundamental for plant reproduction. Nowadays, the work of beekeepers is constrained by external factors that stress their production (parasites and pesticides among others). Taking care of large numbers of beehives is time-consuming, so integrating sensors to track their status can drastically simplify the work of beekeepers. Precision bee-keeping complements beekeepers' work thanks to the In-ternet of Things (IoT) technology. If used correctly, data can help to make the right diagnosis for honey bees colony, increase honey production and decrease bee mortality. Providing enough energy for on-hive and in-hive sensors is a challenge. Some solutions rely on energy harvesting, others target usage of large batteries. Either way, it is mandatory to analyze the energy usage of embedded equipment in order to design an energy efficient and autonomous bee monitoring system. This paper relies on a fully autonomous IoT framework that collects environmental and image data of a beehive. It consists of a data collecting node (environmental data sensors, camera, Raspberry Pi and Arduino) and a solar energy supplying node. Supported services are analyzed task by task from an energy profiling and efficiency standpoint , in order to identify the highly pressured areas of the framework. This first step will guide our goal of designing a sustainable precision beekeeping system, both technically and energy-wise.
description: IoT '20: 10th International Conference on the Internet of Things, Oct 2020, Malm{\"o}, Sweden
Spin Accumulation in the Extrinsic Spin Hall Effect
Creators: name: Tse, Wang-Kong
name: Fabian, J.
name: Zutic, I.
name: Sarma, S. Das
Publisher: name: arXiv
Year: 2005
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The drift-diffusion formalism for spin-polarized carrier transport in semiconductors is generalized to include spin-orbit coupling. The theory is applied to treat the extrinsic spin Hall effect using realistic boundary conditions. It is shown that carrier and spin diffusion lengths are modified by the presence of spin-orbit coupling and that spin accumulation due to the extrinsic spin Hall effect is strongly and qualitatively influenced by boundary conditions. Analytical formulas for the spin-dependent carrier recombination rates and inhomogeneous spin densities and currents are presented.
description: 5 pages, 3 figures
Contractual structure in British Columbia’s silviculture sector : a transaction cost economic analysis
Creators: name: Wang, Sen
Publisher: name: University of British Columbia
Year: 2009

description: This dissertation investigates the effects of institutional reforms in British Columbia's silviculture sector. Based on transaction cost economics, the institutional restructuring in BC's silviculture sector, especially since 1987, is argued to have effected the contractual relationships for silvicultural performances in response to the need to economize on transaction costs. Research emphasis is on forest companies' choice of contractual forms between contracting out and in-house operation. An analytical framework is developed through the presentation of a theory of contractual choices and the identification of a set of transaction cost attributes and firm characteristics. Hypothesis testing is performed by means of probit and ordered probit models, using survey data. Empirical results confirm the general validity of transaction costs theory that firms pick contractual forms in accordance with the attributes of silvicultural activities and firm-specific characteristics. Separate regression analyses have also been conducted to examine the determinants of forest companies' choice of payment schemes such as piece wages and time rates and the determinants of silvicultural contractors' performances. Changes in the structure of silvicultural costs during the period 1987 - 1996 have also been examined through a case study of a major forest company that operates on the BC Coast. The empirical results confirm that contractual forms tend to align with transaction attributes and firm characteristics so that some costs of transacting can be saved. The research findings suggest that neither pure market-based outsourcing nor vertically integrated in-house forms necessarily prevail. Ultimately, the choice of governance modes is dictated by the nature of the transactions involved.
A Bayesian ILC method for CMB B-mode posterior estimation and reconstruction of primordial gravity wave signal
Creators: name: Yadav, Sarvesh Kumar
name: Saha, Rajib
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The Cosmic Microwave Background (CMB) radiation B mode polarization signal contains the unique signature of primordial metric perturbations produced during the inflation. The separation of the weak CMB B-mode signal from strong foreground contamination in observed maps is a complex task, and proposed new generation low noise satellite missions compete with the weak signal level of this gravitational background. In this article, for the first time, we employ a foreground model-independent internal linear combination (ILC) method to reconstruct the CMB B mode signal using simulated observations over large angular scales of the sky of 6 frequency bands of future generation CMB mission Probe of Inflation and Cosmic Origins (PICO). We estimate the joint CMB B mode posterior density following the interleaving Gibbs steps of B mode angular power spectrum and cleaned map samples using the ILC method. We extend and improve the earlier reported Bayesian ILC method to analyze weak CMB B mode reconstruction by introducing noise bias corrections at two stages during the ILC weight estimation. By performing $200$ Monte Carlo simulations of the Bayesian ILC method, we find that our method can reconstruct the CMB signals and the joint posterior density accurately over large angular scales of the sky. We estimate Blackwell-Rao statistics of the marginal density of CMB B mode angular power spectrum and use them to estimate the joint density of scalar to tensor ratio $r$ and a lensing power spectrum amplitude $A^{\textrm{lens}}$. Using $200$ Monte Carlo simulations of the delensing approach, we find that our method can achieve an unbiased detection of the primordial gravitational wave signal $r$ with more than 8$σ$ significance for levels of $r \geqslant 0.01$.
description: 12 pages,13 figures,1 table
Observation of dark state polariton collapses and revivals
Creators: name: Matsukevich, D. N.
name: Chaneliere, T.
name: Jenkins, S. D.
name: Lan, S. -Y.
name: Kennedy, T. A. B.
name: Kuzmich, A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: By time-dependent variation of a control field, both coherent and single photon states of light are stored in, and retrieved from, a cold atomic gas. The efficiency of retrieval is studied as a function of the storage time in an applied magnetic field. A series of collapses and revivals is observed, in very good agreement with theoretical predictions. The observations are interpreted in terms of the time evolution of the collective excitation of atomic spin wave and light wave, known as the dark-state polariton.
description: 5 pages, 4 figures
Scarring for Quantum Maps with Simple Spectrum
Creators: name: Kelmer, Dubi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mathematical Physics (math-ph)
subject: Number Theory (math.NT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We previously introduced a family of symplectic maps of the torus whose quantization exhibits scarring on invariant co-isotropic submanifolds. The purpose of this note is to show that in contrast to other examples, where failure of Quantum Unique Ergodicity is attributed to high multiplicities in the spectrum, for these examples the spectrum is (generically) simple.
description: 5 pages
On the formulations of interfacial force in the phase-field-based lattice Boltzmann method
Creators: name: Zhang, Chunhua
name: Liang, Hong
name: Guo, Zhaoli
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: 76T06

description: Different formulations of interfacial force have been adopted in phase-field-based lattice Boltzmann method for two-phase flows. Although they are identical mathematically, their numerical performances may be different due to truncation errors in the discretization. In this paper, four-type formulations of interfacial force available in the literature, namely stress tensor form (STF), chemical potential form (CPF), pressure form (PF) and continuum surface force (CSF) form, are compared and discussed. A series of benchmark problems, including stationary droplet, two merging droplets, Capillary wave, rising bubble and drop deformation in shear flow, are simulated. Numerical results show that CPF is a good choice for small surface deformation problems while STF is preferred for dynamical problems, both STF and CSF demonstrate good numerical stability.
description: 31pages, 16 figures
Magnetic excitations in {Mo72Fe30}
Creators: name: Garlea, V. O.
name: Nagler, S. E.
name: Zarestky, J. L.
name: Stassis, C.
name: Vaknin, D.
name: Kogerler, P.
name: McMorrow, D. F.
name: Niedermayer, C.
name: Tennant, D. A.
name: Lake, B.
name: Qiu, Y.
name: Exler, M.
name: Schnack, J.
name: Luban, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We report cold-neutron inelastic neutron scattering measurements on deuterated samples of the giant polyoxomolybdate magnetic molecule {Mo72Fe30}. The 30 s = 5/2 Fe+3 ions occupy the vertices of an icosidodecahedron, and interact via antiferromagnetic nearest neighbor coupling. The measurements reveal a band of magnetic excitations near E ~ 0.6 meV. The spectrum broadens and shifts to lower energy as the temperature is increased, and also is strongly affected by magnetic fields. The results can be interpreted within the context of an effective three-sublattice spin Hamiltonian.
description: submitted to Physical Review Letters (4 pages, 3 figures)
Topological Defects Formation with Momentum Dissipation
Creators: name: Li, Zhi-Hong
name: Zeng, Hua-Bi
name: Zhang, Hai-Qing
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We employ holographic techniques to explore the effects of momentum dissipation on the formation of topological defects during the critical dynamics of a strongly coupled superconductor after a linear quench of temperature. The gravity dual is the dRGT massive gravity in which the conservation of momentum in the boundary field theory is broken by the presence of a bulk graviton mass. From the scaling relations of defects number and "freeze-out" time to the quench rate for various graviton masses, we demonstrate that the momentum dissipation induced by graviton mass has little effect on the scaling laws compared to the Kibble-Zurek mechanism. Inspired from Pippard's formula in condensed matter, we propose an analytic relation between the coherence length and the graviton mass, which agrees well with the numerical results from the quasi-normal modes analysis. As a result, the coherence length decreases with respect to the graviton mass, which indicates that the momentum dissipation will augment the number of topological defects.
description: 18 pages, 4 figures, accepted by JHEP
Nachbemerkungen der katholischen Herausgeber zum Beitrag von H. Vorster
Creators: name: Pesch, Otto Hermann
name: Schneider, Theodor
name: Ulrich, Lothar
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 41 Nr. 4 (1992): Ökumenische Rundschau, Band 41, Heft 4
Dynamical evidence of the age--metallicity relation in the Milky Way disk
Creators: name: Rocha-Pinto, H. J.
name: Rangel, R. H. O.
name: de Mello, G. F. Porto
name: Braganca, G. A.
name: Maciel, W. J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We studied the relationship between the average stellar abundance of several elements and the orbital evolution of stars in the neighbourhood of the Sun, using both observational data for 325 late-type dwarfs in a volume-complete sample and simulations of the orbital diffusion. Metallicities, ages, and initial position and velocities for the simulated stars are sampled from empirical distributions of these quantities in the Milky Way. We found that that there is a relationship between the average stellar abundance of Fe, Na, Si, Ca, Ni, and Ba and the mean orbital radius of stars currently passing through the solar neighbourhood. The greater the difference between the mean orbital radius and the solar Galactocentric distance, the more deficient the star is, on average, in these chemical species. The stars that take a longer time to come from their birthplaces to arrive in the present solar neighbourhood are more likely to be more metal-poor than those that were born here. This result is a direct, independent indication that a tightly defined Galactic age-metallicity relation exists.
description: 4 pages, 3 figures. Accepted for publication in the A&A
Identification and characterization of a maturation-inhibited protein kinase (MIPK)
Creators: name: Morrison, Donna Lorraine
Publisher: name: University of British Columbia
Year: 2009

description: A novel homologue of p38 MAP kinase, called maturation-inhibited protein kinase (MIPK), has been cloned from the Pisaster ochraceus oocyte system. MIPK was first recognized as a major tyrosine phosphorylated protein in the immature oocyte, which underwent dephosphorylation in response to the natural hormone 1 -methyladenine. Using an antipeptide antibody based on the C-terminus of cyclin-dependent kinase 5 (Cdk5-CT) as a probe, MIPK was partially purified from seastar oocyte cytosol. Peptide sequence information was used to clone the full length MIPK cDNA. The predicted amino acid sequence of MIPK was found to be most closely related to the p38 MAP kinase. More specifically, MIPK was 65% identical to human p38, 62% identical to human p38β, 56% identical to human p38γ, and 54% identical to p38δ. Analysis of the known p38 kinase family members from diverse species indicates a high degree of conservation (85-95% for p38) in primary structure. MIPK did not show the same level of identity with p38 as did the known p38 homologues, and was therefore defined as a novel member of the p38 MAP kinase family. MIPK was found to be activated in the oocyte system in response to high osmolarity medium and heat shock, confirming MIPK as a stressactivated protein kinase. Assessment of MIPK phosphotyrosine levels during embryonic development showed a dramatic activation of MIPK 12 h post-fertilization. This time course of activation correlated with the transition from synchronous cell divisions to differential cleavages, at a time when the overall rate of cell division decreased. MIPK appeared to be activated in cells arresting in the cell cycle, during meiotic maturation, under stress conditions, or during embryonic development. MIPK may therefore act as a cytostatic factor in the Pisaster ochraceus oocyte syste
Space and time ambiguities in vacuum electrodynamics
Creators: name: Goulart, Érico
name: Bittencourt, Eduardo
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It is shown that every regular electromagnetic field in vacuum identically satisfy Maxwell equations in a new manifold where the roles of space and time have been exchanged. The new metric is Lorentzian, depends on the particular solution and forces the flow of time to tilt somehow in the direction of the field lines. We give a detailed description of the transformation and discuss several of its properties, both in the algebraic and differential settings. Examples are given where the new metrics are explicitly computed and carefully analyzed. We conclude with possible applications of the transformation as well as future perspectives.
description: 22 pages
Additional file 1 of Resting-state hemodynamic changes and effects on upper limb function after multi-channel transcranial direct current stimulation to the ipsilesional primary motor cortex and anterior intraparietal sulcus in stroke patients: an fNIRS pilot study
Creators: name: Lee, Seung Hyun
name: Lee, Gihyoun
name: Kim, Jinuk
name: Phillips V, Zephaniah
name: Kim, Heegoo
name: Kim, Eunmi
name: Lee, Su-Hyun
name: Jeong, Ho Choon
name: Paik, Seung-Ho
name: Kim, Yun-Hee
name: Kim, Beop-Min
Publisher: name: figshare
Year: 2025
Subjects: subject: Medicine
subject: Neuroscience
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biological Sciences not elsewhere classified
subject: Mental Health

description: Supplementary Material 1
Smooth Extensions and Spaces of Smooth and Holomorphic Mappings
Creators: name: Wockel, Christoph
Publisher: name: arXiv
Year: 2005
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 22E65 (Primary), 58A05 (Secondary)

description: In this paper we present another notion of a smooth manifold with corners and relate it to the commonly used concept in the literature. Afterwards we introduce complex manifolds with corners and show that if $M$ is a compact (respectively complex) manifold with corners and $K$ is a smooth (respectively complex) Lie group, then $C^{\infty}(M,K)$ (respectively $C^{\infty}_{\C}(M,K)$) is a smooth (respectively complex) Lie group.
description: 10 pages
On the rise and fall of networked societies
Creators: name: Ehrhardt, George C. M. A.
name: Marsili, Matteo
name: Vega-Redondo, Fernando
Publisher: name: arXiv
Year: 2005
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We review recent results on the dynamics of social networks which suggest that the interplay between the network formation process and volatility may lead to the occurrence of discontinuous phase transitions and phase coexistence in a large class of models. We then investigate the effects of negative links -- links inhibiting local growth of the network -- and of a geographical distribution of the agents in such models. We show, by extensive numerical simulations, that both effects enhance this phenomenology, i.e. it increases the size of the coexistence region.
description: 6 pages, 4 figures, Proceedings of Granada Workshop 2005
A robustness measure for singular point and index estimation in discretized orientation and vector fields
Creators: name: Hoffmann, Karl B.
name: Sbalzarini, Ivo F.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Algebraic Topology (math.AT)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: I.4.7; I.5.2
subject: 55M25, 26B20, 68U10

description: The identification of singular points or topological defects in discretized vector fields occurs in diverse areas ranging from the polarization of the cosmic microwave background to liquid crystals to fingerprint recognition and bio-medical imaging. Due to their discrete nature, defects and their topological charge cannot depend continuously on each single vector, but they discontinuously change as soon as a vector changes by more than a threshold. Considering this threshold of admissible change at the level of vectors, we develop a robustness measure for discrete defect estimators. Here, we compare different template paths for defect estimation in discretized vector or orientation fields. Sampling prototypical vector field patterns around defects shows that the robustness increases with the length of template path, but less so in the presence of noise on the vectors. We therefore find an optimal trade-off between resolution and robustness against noise for relatively small templates, except for the "single pixel" defect analysis, which cannot exclude zero robustness. The presented robustness measure paves the way for uncertainty quantification of defects in discretized vector fields.
description: 4 pages, 1 figure
Shubnikov de Haas effect in the metallic state of Na$_{0.3}$CoO$_2$
Creators: name: Balicas, L.
name: Analytis, J. G.
name: Jo, Y. J.
name: Storr, K.
name: Zandbergen, H.
name: Xin, Y.
name: Hussey, N. E.
name: Chou, F. C.
name: Lee, P. A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Shubnikov de Haas oscillations for two well defined frequencies, corresponding respectively to areas of 0.8 and 1.36% of the first Brillouin zone (FBZ), were observed in single crystals of Na$_{0.3}$CoO$_2$. The existence of Na superstructures in Na$_{0.3}$CoO$_2$, coupled with this observation, suggests the possibility that the periods are due to the reconstruction of the large Fermi surface around the $Γ$ point. An alternative interpretation in terms of the long sought-after $ε_g^\prime$ pockets is also considered but found to be incompatible with existing specific heat data.
description: 5 pages 4 figures
Geht es wirklich nur so? - Die Glaubenskongregation zur Kirche als Communio
Creators: name: Vorster, Hans
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 41 Nr. 4 (1992): Ökumenische Rundschau, Band 41, Heft 4
The Isaac Newton Telescope monitoring survey of Local Group dwarf galaxies -- IV. The star formation history of Andromeda VII derived from long period variable stars
Creators: name: Navabi, Mahdieh
name: Saremi, Elham
name: Javadi, Atefeh
name: Noori, Majedeh
name: van Loon, Jacco Th.
name: Khosroshahi, Habib G.
name: McDonald, Iain
name: Alizadeh, Mina
name: Danesh, Arash
name: Gozaliasl, Ghassem
name: Molaeinezhad, Alireza
name: Parto, Tahere
name: Raouf, Mojtaba
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We have examined the star formation history (SFH) of Andromeda VII (And VII), the brightest and most massive dwarf spheroidal (dSph) satellite of the Andromeda galaxy (M 31). Although M 31 is surrounded by several dSph companions with old stellar populations and low metallicity, it has a metal-rich stellar halo with an age of 6$-$8 Gyr. This indicates that any evolutionary association between the stellar halo of M 31 and its dSph system is frail. Therefore, the question is whether And VII (a high-metallicity dSph located $\sim$220 kpc from M 31), can be associated with M 31's young, metal-rich halo. Here, we perform the first reconstruction of the SFH of And VII employing long-period variable (LPV) stars. As the most-evolved asymptotic giant branch (AGB) and red supergiant (RSG) stars, the birth mass of LPVs can be determined by connecting their near-infrared photometry to theoretical evolutionary tracks. We found 55 LPV candidates within two half-light radii, using multi-epoch imaging with the Isaac Newton Telescope in the $i$ and $V$ bands. Based on their birth mass function, the star-formation rate (SFR) of And VII was obtained as a function of cosmic time. The main epoch of star formation occurred $\simeq 6.2$ Gyr ago with a SFR of $0.006\pm0.002$ M$_\odot$ yr$^{-1}$. Over the past 6 Gyr, we find slow star formation, which continued until 500 Myr ago with a SFR $\sim0.0005\pm0.0002$ M$_\odot$ yr$^{-1}$. We determined And VII's stellar mass $M=(13.3\pm5.3)\times10^6$ M$_\odot$ within a half-light radius $r_{\frac{1}{2}}=3.8\pm0.3$ arcmin and metallicity $Z=0.0007$, and also derived its distance modulus of $μ=24.38$ mag.
description: Accepted for publication in ApJ
Social and cultural norms of the different communities and ethical challenges in researching young language learners
Creators: name: Pinter, Annamaria
Publisher: name: Zenodo
Year: 2021

description: Collecting data with and about young children: ethical and methodological issues 4th March 2021 3.00-4.50pm CET This Webinar is organized by the Multilingual Childhoods / REYLL research network Committee (Responsible: Dr. Fatma Said, Assistant Professor in Applied Linguistics at Zayed University, UAE). In our third online webinar we invite esteemed researchers and scholars who focus on researching young children’s language learning and their reflections on their learning process. Although, there is much research on children rarely is there an opportunity for students, early career scholars and researchers to meet and discuss tried and tested approaches to the topic, as well as possible future approaches. Much information in books does not allow for questions to be posed or for researchers to share actual experiences in an easy-to-access manner. Importantly, the invited speakers also cover issues of ethics and methodologies, which usually pose a challenge to researchers and having access to such a discussion is usually difficult. Hence, this unique webinar will create a space of discussion and learning by asking two central questions: “What can we learn from doing research with children as active agents?” and “What are ethical issues in studying children’s beliefs and reflections on their learning process?”
Specificity at the b mating type locus of ustilago maydis
Creators: name: Yee, Arthur Raymond
Publisher: name: University of British Columbia
Year: 2009

description: The ability to discriminate between self and nonself allows Ustilago maydis to maintain genetic diversity through a multiallelic mating type system governed by the b locus. There are approximately 25 different alleles of the b locus and a given individual is incompatible with "self, but compatible with all "nonself mating types. The b locus consists of two divergently transcribed genes, designated bE and bW, and recognition of "self occurs because bE and bW proteins from the same allele do not dimerize. Conversely, bE and bW proteins encoded by two different b alleles do form dimers, and these dimers are active as homeodomain transcription factors, regulating the processes of sexual reproduction and pathogenicity. The N-terminal domains of both bE and bW have been shown to contain the determinants of dimerization specificity. A large set of closely spaced chimeric alleles was constructed for each of the interacting genes, one set of bEl-bE2 chimeras, and another of bWl-bW2 chimeras. The specificity of each chimeric allele was determined and they fell into three classes; bl (class I), b2 (class DI), and specificity different from either bl or b2 (class IT). The close spacing of the chimeric alleles allowed specificity changes at class boundaries to be attributed to single amino acid differences. An examination of substitutions affecting specificity revealed that 3 out of 8 involved an amino acid with an aromatic side chain (Tyr or Phe). To gain further insight into the interaction between bE and bW, strains carrying chimeric alleles of bE and bW were crossed in all pairwise combinations. The patterns of compatible and incompatible crosses identified intermolecular interactions between two pairs of positions on bE and bW. Site directed mutagenesis was employed to confirm the interaction between one of these pairs of positions. The results indicated that Val at position 90 of bEl and Tyr at position 74 of bWl interact, either directly or indirectly, to inhibit dimerization between bEl and bWl. These data provide evidence for an "inhibitory determinant" model, whereby specificity between bE and bW proteins is mediated by residues that prevent interaction between self combinations.
Semi-inclusive charged-current neutrino-nucleus cross sections in the relativistic plane wave impulse approximation
Creators: name: Franco-Patino, J. M.
name: Gonzalez-Rosa, J.
name: Caballero, J. A.
name: Barbaro, M. B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Neutrino-nucleus quasielastic scattering is studied in the plane wave impulse approximation for three nuclear models: the relativistic Fermi gas (RFG), the independent-particle shell model (IPSM) and the natural orbitals (NO) model with Lorentzian dependence of the excitation energy. A complete study of the kinematics of the semi-inclusive process and the associated cross sections are presented and discussed for 40 Ar and 12 C. Inclusive cross sections are also obtained by integrating the semi-inclusive expressions over the outgoing hadron. Results are consistent with previous studies restricted to the inclusive channel. In particular, a comparison with the analytical results for the RFG model is performed. Explicit expressions for the hadronic tensor and the 10 semi-inclusive nuclear responses are given. Theoretical predictions are compared with semi-inclusive experimental data from T2K experiment.
description: 55 pages, 22 figures, submitted to Physical Review C
Additional file 1 of Identification of novel TCOF1 mutations in Treacher Collins syndrome and their functional characterization
Creators: name: Chen, Ying
name: Yang, Run
name: Chen, Xin
name: Zhang, Tianyu
name: Li, Chenlong
name: Ma, Jing
Publisher: name: figshare
Year: 2025
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Supplementary material 1.