cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
An Improved Algorithm for Fast K-Word Proximity Search Based on Multi-Component Key Indexes
Creators: name: Veretennikov, Alexander B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: A search query consists of several words. In a proximity full-text search, we want to find documents that contain these words near each other. This task requires much time when the query consists of high-frequently occurring words. If we cannot avoid this task by excluding high-frequently occurring words from consideration by declaring them as stop words, then we can optimize our solution by introducing additional indexes for faster execution. In a previous work, we discussed how to decrease the search time with multi-component key indexes. We had shown that additional indexes can be used to improve the average query execution time up to 130 times if queries consisted of high-frequently occurring words. In this paper, we present another search algorithm that overcomes some limitations of our previous algorithm and provides even more performance gain. This is a pre-print of a contribution published in Arai K., Kapoor S., Bhatia R. (eds) Intelligent Systems and Applications. IntelliSys 2020. Advances in Intelligent Systems and Computing, vol 1251, published by Springer, Cham. The final authenticated version is available online at: https://doi.org/10.1007/978-3-030-55187-2_37
Variable-order fractional master equation and clustering of particles: non-uniform lysosome distribution
Creators: name: Fedotov, Sergei
name: Han, Daniel
name: Zubarev, Andrey Yu.
name: Johnston, Mark
name: Allan, Victoria J
Publisher: name: arXiv
Year: 2021
Subjects: subject: Subcellular Processes (q-bio.SC)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: In this paper, we formulate the space-dependent variable-order fractional master equation to model clustering of particles, organelles, inside living cells. We find its solution in the long time limit describing non-uniform distribution due to a space dependent fractional exponent. In the continuous space limit, the solution of this fractional master equation is found to be exactly the same as the space-dependent variable-order fractional diffusion equation. In addition, we show that the clustering of lysosomes, an essential organelle for healthy functioning of mammalian cells, exhibit space-dependent fractional exponents. Furthermore, we demonstrate that the non-uniform distribution of lysosomes in living cells is accurately described by the asymptotic solution of the space-dependent variable-order fractional master equation. Finally, Monte Carlo simulations of the fractional master equation validate our analytical solution.
description: arXiv admin note: text overlap with arXiv:1902.03087
Gluons in glueballs: Spin or helicity?
Creators: name: Mathieu, V.
name: Buisseret, F.
name: Semay, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the last decade, lattice QCD has been able to compute the low-lying glueball spectrum with accuracy. Like other effective approaches of QCD, potential models still have difficulties to cope with gluonic hadrons. Assuming that glueballs are bound states of valence gluons with zero current mass, it is readily understood that the use of a potential model, intrinsically non covariant, could be problematic in this case. The main challenge for this kind of model is actually to find a way to introduce properly the more relevant degree of freedom of the gluon: spin or helicity. In this work, we use the so-called helicity formalism of Jacob and Wick to describe two-gluon glueballs. We show in particular that this helicity formalism exactly reproduces the $J^{PC}$ numbers which are observed in lattice QCD when the constituent gluons have a helicity-1, without introducing extra states as it is the case in most of the potential models. These extra states appear when gluons are seen as spin-1 particles. Using a simple spinless Salpeter model with Cornell potential within the helicity formalism, we obtain a glueball mass spectrum which is in good agreement with lattice QCD predictions for helicity-1 gluons provided instanton-induced interactions are taken into account.
description: 2 figures, section III.B corrected but conclusions unchanged
Magnetism and electrical transport in Y-doped layered iridate Sr$_2$IrO$_4$
Creators: name: Bhatti, Imtiaz Noor
name: Pramanik, A. K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Here, we report an investigation of structural, magnetic and electronic properties in Y-doped layered iridate (Sr$_{1-x}$Y$_x$)$_2$IrO$_4$ ($x$ $\leq$ 0.1). The parent Sr$_2$IrO$_4$ is a well-studied spin-orbit coupling (SOC) induced insulator with an antiferromagnetic ground state. The Y-doping here equivalently acts for electron doping without altering the vital parameters such as, SOC and electron correlation. Experimental results show a minute change in structural parameters and an equivalent charge conversion from Ir$^{4+}$ to Ir$^{3+}$. Unlike similarly other electron-doped system, the low temperature magnetic and electronic state in present series is minimally influenced. The charge conduction mechanism follows 2-dimensional hopping model in whole series. Magnetoresistance (MR) data show an interesting sign change with both temperature and magnetic field. The positive MR both at low temperature follows weak antilocalization behavior where the sign change in MR is believed to be caused by an interplay between SOC and magnetic moment.
description: 12 pages, 8 figures
Spectroscopy of the parametric magnons excited by 4-wave process
Creators: name: De Loubens, G.
name: Naletov, V. V.
name: Charbois, Vincent
name: Klein, Olivier
name: Tiberkevich, V. S.
name: Slavin, Andrei
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using a Magnetic Resonace Force Microscope, we have performed ferromagnetic resonance (FMR) spectroscopy on parametric magnons created by 4-wave process. This is achieved by measuring the differential response to a small source modulation superimposed to a constant excitation power that drives the dynamics in the saturation regime of the transverse component. By sweeping the applied field, we observe abrupt readjustement of the total number of magnons each time the excitation coincides with a parametric mode. This gives rise to ultra-narrow peaks whose linewith is lower than $5~10^{-6}$ of the applied field.
description: 4 pages
Consistent couplings between spin-2 and spin-3 massless fields
Creators: name: Boulanger, Nicolas
name: Leclercq, Serge
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We solve the problem of constructing consistent first-order cross-interactions between spin-2 and spin-3 massless fields in flat spacetime of arbitrary dimension n > 3 and in such a way that the deformed gauge algebra is non-Abelian. No assumptions are made on the number of derivatives involved in the Lagrangian, except that it should be finite. Together with locality, we also impose manifest Poincare invariance, parity invariance and analyticity of the deformations in the coupling constants.
description: LaTeX file. 29 pages, no figures. Minor corrections. Accepted for publication in JHEP
Adiabatic and Nonadiabatic Spin-transfer Torques in Antiferromagnets
Creators: name: Fujimoto, Junji
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Electron transport in magnetic orders and the magnetic orders dynamics have a mutual dependence, which provides the key mechanisms in spin-dependent phenomena. Recently, antiferromagnetic orders are focused on as the magnetic order, where current-induced spin-transfer torques, a typical effect of electron transport on the magnetic order, have been debatable mainly because of the lack of an analytic derivation based on quantum field theory. Here, we construct the microscopic theory of spin-transfer torques on the slowly-varying staggered magnetization in antiferromagnets with weak canting. In our theory, the electron is captured by bonding/antibonding states, each of which is the eigenstate of the system, doubly degenerates, and spatially spreads to sublattices because of electron hopping. The spin of the eigenstates depends on the momentum in general, and a nontrivial spin-momentum locking arises for the case with no site inversion symmetry, without considering any spin-orbit couplings. The spin current of the eigenstates includes an anomalous component proportional to a kind of gauge field defined by derivatives in momentum space and induces the adiabatic spin-transfer torques on the magnetization. Unexpectedly, we find that one of the nonadiabatic torques has the same form as the adiabatic spin-transfer torque, while the obtained forms for the adiabatic and nonadiabatic spin-transfer torques agree with the phenomenological derivation based on the symmetry consideration. This finding suggests that the conventional explanation for the spin-transfer torques in antiferromagnets should be changed. Our microscopic theory provides a fundamental understanding of spin-related physics in antiferromagnets.
Does double-blind peer-review reduce bias? Evidence from a top computer science conference
Creators: name: Sun, Mengyi
name: Danfa, Jainabou Barry
name: Teplitskiy, Misha
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computers and Society (cs.CY)
subject: Digital Libraries (cs.DL)
subject: General Economics (econ.GN)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business

description: Peer review is widely regarded as essential for advancing scientific research. However, reviewers may be biased by authors' prestige or other characteristics. Double-blind peer review, in which the authors' identities are masked from the reviewers, has been proposed as a way to reduce reviewer bias. Although intuitive, evidence for the effectiveness of double-blind peer review in reducing bias is limited and mixed. Here, we examine the effects of double-blind peer review on prestige bias by analyzing the peer review files of 5027 papers submitted to the International Conference on Learning Representations (ICLR), a top computer science conference that changed its reviewing policy from single-blind peer review to double-blind peer review in 2018. We find that after switching to double-blind review, the scores given to the most prestigious authors significantly decreased. However, because many of these papers were above the threshold for acceptance, the change did not affect paper acceptance decisions significantly. Nevertheless, we show that double-blind peer review may have improved the quality of the selections by limiting other (non-author-prestige) biases. Specifically, papers rejected in the single-blind format are cited more than those rejected under the double-blind format, suggesting that double-blind review better identifies poorer quality papers. Interestingly, an apparently unrelated change - the change of rating scale from 10 to 4 points - likely reduced prestige bias significantly, to an extent that affected papers' acceptance. These results provide some support for the effectiveness of double-blind review in reducing prestige bias, while opening new research directions on the impact of peer review formats.
An exact solution of the observable universe in Bianchi V space-time
Creators: name: Prasad, Rajendra
name: Singh, Manvinder
name: Yadav, Anil Kumar
name: Beesham, A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In this paper we investigate an observable universe in Bianchi type V space-time by taking into account the cosmological constant as the source of energy. We have performed a $χ^{2}$ test to obtain the best fit values of the model parameters of the universe in the derived model. We have used two types of data sets, viz: i) 31 values of the Hubble parameter and ii) the 1048 Phanteon data set of various supernovae distance moduli and apparent magnitudes. From both the data sets, we have estimated the current values of the Hubble constant, density parameters $(Ω_{m})_{0}$ and $(Ω_Λ)_{0}$. The present value of deceleration parameter of the universe in derived model is obtained as $q_{0} = 0.59^{+0.04}_{-0.03}$ and $0.59^{+0.02}_{-0.03}$ in accordance with $H(z)$ and Pantheon data respectively. Also we observe that there is a signature flipping in the sign of deceleration parameter from positive to negative and transition red-shift exists. Thus, the universe in derived model represents a transitioning universe which is in accelerated phase of expansion at present epoch. We have estimated the current age of the universe $(t_{0})$ and present value of jerk parameter $(j_{0})$. Our obtained values of $t_{0}$ and $j_{0}$ are in good agreement with its values estimated by Plank collaborations and WMAP observations.
description: 7 pages, 4 figure panels
An experimental study of the use and effects of hypertext-based explanations in knowledge-based systems
Creators: name: Mao, Jiye
Publisher: name: University of British Columbia
Year: 2009

description: Since MYCIN, explanation has become a fundamental feature of knowledge-based systems (KBS). Among the common deficiencies of KBS explanations, the most acute one is the lack of knowledge. This dissertation research investigates the use of explanations provided with hypertext for increasing the availability and accessibility of domain knowledge. The ultimate objective is to determine the behavioral and cognitive basis of the use of hypertext in providing KBS explanations. Two informationally equivalent KBS were comparatively studied in a laboratory setting: one used hypertext to provide explanations, while the other one used conventional lineartext. The experiment involved 26 experienced professionals, and 29 undergraduate and graduate students specializing in accounting. Subjects used the experimental KBS to work on a realistic problem of financial analysis. Both the process and outcomes of explanation use were assessed. Outcome variables included improvement in decision accuracy, trust in the KBS, and perceived usefulness of explanations. In addition to questionnaires used to measure decision accuracy and perceptions, computer logs were used to capture the number, type, and context of explanation use. Thinkingaloud procedures were used to assess the nature of explanation use. Results indicate that the use of hypertext for providing explanations significantly improved decision accuracy, and influenced users' preference for explanation types, and the number and context of explanation requests. Enhanced accessibility to deep explanations via the use of hypertext significantly increased the number of deep explanations requested by both novices and experts. Verbal protocol analysis shows that the lack of knowledge and means of accessing deep explanations could make it difficult to understand KBS recommendations, and that deep explanations could improve the understandability of KBS advice, especially in cases where unfamiliar domain concepts were involved. In the hypertext group, about 37% of the deep explanations were requested in the context of judgment making, rather than in the abstract. While only about 28% of the deep explanations requested by the lineartext group were the How type, 42% were the How type for the hypertext group. Experts and novices had different preferences for explanation types. Experts requested a much higher percentage of How, and lower percentages of Why and Strategic explanations, than novices. Verbal protocol analysis illustrates that experts and novices used explanations for different purposes.
Counting BPS Baryonic Operators in CFTs with Sasaki-Einstein duals
Creators: name: Butti, Agostino
name: Forcella, Davide
name: Zaffaroni, Alberto
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study supersymmetric D3 brane configurations wrapping internal cycles of type II backgrounds AdS(5) x H for a generic Sasaki-Einstein manifold H. These configurations correspond to BPS baryonic operators in the dual quiver gauge theory. In each sector with given baryonic charge, we write explicit partition functions counting all the BPS operators according to their flavor and R-charge. We also show how to extract geometrical information about H from the partition functions; in particular, we give general formulae for computing volumes of three cycles in H.
description: 46 pages, 10 figures; comments and clarifications added, published version
Thermal critical behavior and universality aspects of the three-dimensional random-field Ising model
Creators: name: Malakis, A.
name: Fytas, N. G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The three-dimensional bimodal random-field Ising model is investigated using the N-fold version of the Wang-Landau algorithm. The essential energy subspaces are determined by the recently developed critical minimum energy subspace technique, and two implementations of this scheme are utilized. The random fields are obtained from a bimodal discrete $(\pmΔ)$ distribution, and we study the model for various values of the disorder strength $Δ$, $Δ=0.5, 1, 1.5$ and 2, on cubic lattices with linear sizes $L=4-24$. We extract information for the probability distributions of the specific heat peaks over samples of random fields. This permits us to obtain the phase diagram and present the finite-size behavior of the specific heat. The question of saturation of the specific heat is re-examined and it is shown that the open problem of universality for the random-field Ising model is strongly influenced by the lack of self-averaging of the model. This property appears to be substantially depended on the disorder strength.
description: 17 pages, 6 figures
Cosmological evolution of a scalar-charged degenerate cosmological plasma with Higgs scalar fields
Creators: name: Ignat'ev, Yu. G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: A mathematical model of the cosmological evolution of statistical systems of scalarly charged particles with Higgs scalar interaction is formulated and investigated. Examples are given of numerical modeling of such systems, revealing their very remarkable properties, in particular, the formation of paired bursts of cosmological acceleration.
description: 11 pages, 12 figures, 16 references
3D mapping of the Crab Nebula with SITELLE. I. Deconvolution and kinematic reconstruction
Creators: name: Martin, Thomas
name: Milisavljevic, Danny
name: Drissen, Laurent
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present a hyperspectral cube of the Crab Nebula obtained with the imaging Fourier transform spectrometer SITELLE on the Canada-France-Hawaii telescope. We describe our techniques used to deconvolve the 310 000 individual spectra (R = 9 600) containing Halpha, [NII]6548,6583, and [SII]6716,6731 emission lines and create a detailed three-dimensional reconstruction of the supernova remnant assuming uniform global expansion. We find that the general boundaries of the 3D volume occupied by the Crab are not strictly ellipsoidal as commonly assumed, and instead appear to follow a "heart-shaped" distribution that is symmetrical about the plane of the pulsar wind torus. Conspicuous restrictions in the bulk distribution of gas consistent with constrained expansion coincide with positions of the dark bays and east-west band of He-rich filaments, which may be associated with interaction with a pre-existing circumstellar disk. The distribution of filaments follows an intricate honeycomb-like arrangement with straight and rounded boundaries at large and small scales that are anti-correlated with distance from the center of expansion. The distribution is not unlike the large-scale rings observed in supernova remnants 3C 58 and Cassiopeia A, where it has been attributed to turbulent mixing processes that encouraged outwardly expanding plumes of radioactive 56Ni-rich ejecta. These characteristics reflect critical details of the original supernova of 1054 CE and its progenitor star, and may favour a low-energy explosion of an iron-core progenitor. We demonstrate that our main findings are robust despite regions of non-homologous expansion driven by acceleration of material by the pulsar wind nebula.
description: 20 pages, 18 figures. Accepted for publication by MNRAS. For associated movie files, see http://celeste.phy.ulaval.ca/links/M1-movie/out-outreach.mp4 and http://celeste.phy.ulaval.ca/links/M1-movie/out-science-compressed.mp4
Metallic conduction and superconductivity in the pseudogap phase
Creators: name: Sarker, Sanjoy K
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We analyze the t-J model on a square lattice using bosonic spinons and fermionic holons for low density x of holes. Spinons are paired into singlets, which condense below a temperature T*. The condensate evolves out of the Mott phase - preserving its symmetry. For T > T* holons and spinons are confined (by gauge forces), so that there is no coherent charge propagation. Metallic conduction and d-wave superconductivity result from separate, sublattice-preserving, holon hopping processes which originate below T* from a coupling with the condensate. A simple effective Hamiltonian describing these processes is derived and solved. Holons form a charge Fermi liquid, becoming incoherent (confined) above T*. In the superconductor holons hop as pairs, reducing kinetic energy. The two-sublattice property is the glue that connects the three phases; its effect can be seen in various correlation functions. The theory can account for many features of the cuprate superconductors, including the origin of two-dimensional metallicity.
description: 7 pages 5 Postscript figures
Classifying fermionic states via many-body correlation measures
Creators: name: Semenyakin, Mykola
name: Cheipesh, Yevheniia
name: Herasymenko, Yaroslav
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mathematical Physics (math-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Understanding the structure of quantum correlations in a many-body system is key to its computational treatment. For fermionic systems, correlations can be defined as deviations from Slater determinant states. The link between fermionic correlations and efficient computational physics methods is actively studied but remains ambiguous. We make progress in establishing this connection mathematically. In particular, we find a rigorous classification of states relative to $k$-fermion correlations, which admits a computational physics interpretation. Correlations are captured by a measure $ω_k$, a function of $k$-fermion reduced density matrix that we call twisted purity. A condition $ω_k=0$ for a given $k$ puts the state in a class $G_k$ of correlated states. Sets $G_k$ are nested in $k$, and Slater determinants correspond to $k = 1$. Classes $G_{k=O(1)}$ are shown to be physically relevant, as $ω_k$ vanishes or nearly vanishes for truncated configuration-interaction states, perturbation series around Slater determinants, and some nonperturbative eigenstates of the 1D Hubbard model. For each $k = O(1)$, we give an explicit ansatz with a polynomial number of parameters that covers all states in $G_k$. Potential applications of this ansatz and its connections to the coupled-cluster wavefunction are discussed.
description: 6+12 pages, 2 figures
Active and inactive components of the streamwise velocity in wall-bounded turbulence
Creators: name: Deshpande, Rahul
name: Monty, Jason P.
name: Marusic, Ivan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Townsend (1961) introduced the concept of active and inactive motions for wall-bounded turbulent flows, where the active motions are solely responsible for producing the Reynolds shear stress, the key momentum transport term in these flows. While the wall-normal component of velocity is associated exclusively with the active motions, the wall-parallel components of velocity are associated with both active and inactive motions. In this paper, we propose a method to segregate the active and inactive components of the 2-D energy spectrum of the streamwise velocity, thereby allowing us to test the self-similarity characteristics of the former which are central to theoretical models for wall-turbulence. The approach is based on analyzing datasets comprising two-point streamwise velocity signals coupled with a spectral linear stochastic estimation (SLSE) based procedure. The data considered span a friction Reynolds number range $Re_τ$ $\sim$ ${\mathcal{O}}$($10^3$) -- ${\mathcal{O}}$($10^4$). The procedure linearly decomposes the full 2-D spectrum ($Φ$) into two components, $Φ_{ia}$ and $Φ_{a}$, comprising contributions predominantly from the inactive and active motions, respectively. This is confirmed by $Φ_{a}$ exhibiting wall-scaling, for both streamwise and spanwise wavelengths, corresponding well with the Reynolds shear stress cospectra reported in the literature. Both $Φ_{a}$ and $Φ_{ia}$ are found to depict prominent self-similar characteristics in the inertially dominated region close to the wall, suggestive of contributions from Townsend's attached eddies. Inactive contributions from the attached eddies reveal pure $k^{-1}$-scaling for the associated 1-D spectra (where $k$ is the streamwise/spanwise wavenumber), lending empirical support to the attached eddy model of Perry & Chong (1982).
description: 22 pages, 8 figures, submitted to the Journal of Fluid Mechanics
AiiDAlab -- an ecosystem for developing, executing, and sharing scientific workflows
Creators: name: Yakutovich, Aliaksandr V.
name: Eimre, Kristjan
name: Schütt, Ole
name: Talirz, Leopold
name: Adorf, Carl S.
name: Andersen, Casper W.
name: Ditler, Edward
name: Du, Dou
name: Passerone, Daniele
name: Smit, Berend
name: Marzari, Nicola
name: Pizzi, Giovanni
name: Pignedoli, Carlo A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences
subject: J.2; I.6; H.4

description: Cloud platforms allow users to execute tasks directly from their web browser and are a key enabling technology not only for commerce but also for computational science. Research software is often developed by scientists with limited experience in (and time for) user interface design, which can make research software difficult to install and use for novices. When combined with the increasing complexity of scientific workflows (involving many steps and software packages), setting up a computational research environment becomes a major entry barrier. AiiDAlab is a web platform that enables computational scientists to package scientific workflows and computational environments and share them with their collaborators and peers. By leveraging the AiiDA workflow manager and its plugin ecosystem, developers get access to a growing range of simulation codes through a python API, coupled with automatic provenance tracking of simulations for full reproducibility. Computational workflows can be bundled together with user-friendly graphical interfaces and made available through the AiiDAlab app store. Being fully compatible with open-science principles, AiiDAlab provides a complete infrastructure for automated workflows and provenance tracking, where incorporating new capabilities becomes intuitive, requiring only Python knowledge.
description: Manuscript: 25 pages, 6 figures. Supplementary information: 15 pages, 10 figures
Well-being and morbid obesity in women
Creators: name: Tanco, Sheryl Anne
Publisher: name: University of British Columbia
Year: 2009

description: Obesity is a prevalent disorder associated with myriad psychological and physiological problems. Dietary restraint alone is ineffective in treating obesity and can instead exacerbate the problem. Regular physical exercise is fundamental to successful management of weight problems as well as to generalized physical and psychological well-being. In Study 1, demographic and psychometric variables from obese women, referred over an eight year period to a hospital psychology department for weight management, were reviewed. Findings suggest that such obese women are mildly depressed, anxious, perceive themselves as lacking in self-control and have elevated levels of eating-related psychopathology. In addition to such psychological distress, morbidly obese women are also at risk physiologically. As morbidly obese individuals are unlikely to maintain weights at normative levels, goals and treatments aimed at alleviating these problems, independent of attempts at significant weight loss, seem appropriate. A group treatment programme (CT), based, in part, on the principals of cognitive therapy was developed. The programme incorporated a nondieting approach, encouraged nonchaotic eating and regular exercise, and promoted the use of alternative coping skills; weight loss per se was not a focus of the intervention. Study 2 presents pre- and post-treatment results from a group of 15 morbidly obese women completing this programme. Following treatment, these women were significantly less depressed and anxious and showed lower levels of eating-related psychopathology. By the end of treatment, significantly more of the women were exercising regularly. Given the promising nature of these results, a controlled, comparative treatment outcome study (Study 3) was embarked upon. Sixty-two women, each with a body mass index of at least 30 kg/m 2, were randomly assigned to either the above-described CT programme, a behaviour therapy weight loss programme (BT) or a wait-list control group. Women in both active treatment groups lost significant amounts of weight, while members of the control group had a nonsignificant increase in weight. For CT participants, depression, anxiety, and eating-related psychopathology decreased significantly over the course of treatment while perceptions of self control increased significantly. In contrast, BT and control subjects showed no significant changes in these psychological variables. Relative to control subjects, significantly greater proportions of CT and BT subjects were exercising regularly by the end of treatment. At six month follow-up, data from approximately half the original CT and BT participants were obtained. Statistically, these subjects did not show significant changes across time in terms of weight or psychometric variables. Variables possibly mediating the differential effects of the two treatments are discussed, as are limitations to the current work and directions for future research.
Strong-Coupling Gauge Theory of Nodal Spinons and Antiferromagnetic Phase Transitions
Creators: name: Ichinose, Ikuo
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: In this paper we shall study a gauge theory of nodal spinons which appears as a low-energy effective theory for antiferromagnetic (AF) Heisenberg models. In most of studies on the nodal spinons given so far, the gauge interaction between spinons was assumed weak and nonperturbative effects like instantons and vortices were ignored. In the present paper, we shall study strong-coupling gauge theory of nodal spinons and reveal its nontrivial phase structure. To this end, we employ recently developed lattice gauge theory techniques for studying finite-temperature and finite-density gauge theory. At low temperature and low spinon-density region, an AF long-range order exists. As temperature and/or density of spinons are increases, a phase transition to nonmagnetic phase takes place. Order of the phase transition is of second (first) order for low (high) density region of spinons. At a quantum critical point at vanishing temperature T=0, abrupt change of spinon density occurs as a function of the chemical potential. Implications of the results to the heavy-fermion materials and the high-$T_c$ cuprates are discussed.
description: 15 pages and 6 figures, the version to appear in Mod.Phys.Lett.A
Momentum dependent light scattering in insulating cuprates
Creators: name: Vernay, F. H.
name: Gingras, M. J. P.
name: Devereaux, T. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We investigate the problem of inelastic x-ray scattering in the spin$-{1/2}$ Heisenberg model on the square lattice. We first derive a momentum dependent scattering operator for the $A_{1g}$ and $B_{1g}$ polarization geometries. On the basis of a spin-wave analysis, including magnon-magnon interactions and exact-diagonalizations, we determine the qualitative shape of the spectra. We argue that our results may be relevant to help interpret inelastic x-ray scattering experiments in the antiferromagnetic phase of the cuprates.
description: 5 pages, 3 figures, to appear in PRB
Transverse Momentum Broadening of a Fast Quark in a $\N=4$ Yang Mills Plasma
Creators: name: Casalderrey-Solana, Jorge
name: Teaney, Derek
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We compute the momentum broadening of a heavy fundamental charge propagating through a $\mathcal{N}=4$ Yang Mills plasma at large t' Hooft coupling. We do this by expressing the medium modification of the probe's density matrix in terms of a Wilson loop averaged over the plasma. We then use the AdS/CFT correspondence to evaluate this loop, by identifying the dual semi-classical string solution. The calculation introduces the type ``1'' and type ``2'' fields of the thermal field theory and associates the corresponding sources with the two boundaries of the AdS space containing a black hole. The transverse fluctuations of the endpoints of the string determine $κ_T = \sqrt{γλ} T^3 π$ -- the mean squared momentum transfer per unit time. ($γ$ is the Lorentz gamma factor of the quark.) The result reproduces previous results for the diffusion coefficient of a heavy quark. We compare our results with previous AdS/CFT calculations of $\hat{q}$.
description: 19 pages. v3 references added, validity region corrected
Characterizing the line emission from molecular clouds. Stratified random sampling of the Perseus cloud
Creators: name: Tafalla, M.
name: Usero, A.
name: Hacar, A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: $Context.$ The traditional approach to characterize the structure of molecular clouds is to map their line emission. $Aims.$ We aim to test and apply a stratified random sampling technique that can characterize the line emission from molecular clouds more efficiently than mapping. $Methods.$ We sampled the molecular emission from the Perseus cloud using the H2 column density as a proxy. We divided the cloud into ten logarithmically spaced column density bins, and we randomly selected ten positions from each bin. The resulting 100 cloud positions were observed with the IRAM 30m telescope, covering the 3mm-wavelength band and parts of the 2 and 1mm bands. $Results.$ We focus our analysis on 11 molecular species detected toward most column density bins. In all cases, the line intensity is tightly correlated with the H2 column density. For the CO isotopologs, the trend is relatively flat, while for high-dipole moment species such as HCN, CS, and HCO+ the trend is approximately linear. We reproduce this behavior with a cloud model in which the gas density increases with column density, and where most species have abundance profiles characterized by an outer photodissociation edge and an inner freeze-out drop. The intensity behavior of the high-dipole moment species arises from a combination of excitation effects and molecular freeze out, with some modulation from optical depth. This quasi-linear dependence with the H2 column density makes the gas at low column densities dominate the cloud-integrated emission. It also makes the emission from most high-dipole moment species proportional to the cloud mass inside the photodissociation edge. $Conclusions.$ Stratified random sampling is an efficient technique for characterizing the emission from whole molecular clouds. It shows that despite the complex appearance of Perseus, its molecular emission follows a relatively simple pattern.
description: 27 pages, 19 figures, accepted for publication in A&A
Use of dynamical coupling for improved quantum state transfer
Creators: name: Lyakhov, A. O.
name: Bruder, C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose a method to improve quantum state transfer in transmission lines. The idea is to localize the information on the last qubit of a transmission line, by dynamically varying the coupling constants between the first and the last pair of qubits. The fidelity of state transfer is higher then in a chain with fixed coupling constants. The effect is stable against small fluctuations in the system parameters.
description: 5 pages, 7 figures
A SUSY SU(5) Grand Unified Model of Tri-Bimaximal Mixing from A4
Creators: name: Altarelli, Guido
name: Feruglio, Ferruccio
name: Hagedorn, Claudia
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss a grand unified model based on SUSY SU(5) in extra dimensions and on the flavour group A4xU(1) which, besides reproducing tri-bimaximal mixing for neutrinos with the accuracy required by the data, also leads to a natural description of the observed pattern of quark masses and mixings.
description: 19 pages
Epitaxial graphene/Ge interfaces: a minireview
Creators: name: Dedkov, Yuriy
name: Voloshina, Elena
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The recent discovery of the ability to perform direct epitaxial growth of graphene layers on semiconductor Ge surfaces led to the huge interest to this topic. One of the reasons for this interest is the chance to overcome several present-day drawbacks on the way of the graphene integration in the modern semiconductor technology. The other one is connected with the fundamental studies of the new graphene-semiconductor interfaces, that might help with the deeper understanding of mechanisms, which governs graphene growth on different substrates as well as shed light on the interaction of graphene with these substrates, which range is now spread from metals to insulators. The present minireview gives a timely overview of the state-of-the-art in the field of studies of the graphene-Ge epitaxial interfaces and draw some perspective directions in this research area.
description: 11 pages, 6 figures
New Debris Disks Around Nearby Main Sequence Stars: Impact on The Direct Detection of Planets
Creators: name: Beichman, C.
name: Bryden, G.
name: Stapelfeldt, K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using the MIPS instrument on the Spitzer telescope, we have searched for infrared excesses around a sample of 82 stars, mostly F, G, and K main-sequence field stars, along with a small number of nearby M stars. These stars were selected for their suitability for future observations by a variety of planet-finding techniques. These observations provide information on the asteroidal and cometary material orbiting these stars - data that can be correlated with any planets that may eventually be found. We have found significant excess 70um emission toward 12 stars. Combined with an earlier study, we find an overall 70um excess detection rate of $13 \pm 3$% for mature cool stars. Unlike the trend for planets to be found preferentially toward stars with high metallicity, the incidence of debris disks is uncorrelated with metallicity. By newly identifying 4 of these stars as having weak 24um excesses (fluxes $\sim$10% above the stellar photosphere), we confirm a trend found in earlier studies wherein a weak 24um excess is associated with a strong 70um excess. Interestingly, we find no evidence for debris disks around 23 stars cooler than K1, a result that is bolstered by a lack of excess around any of the 38 K1-M6 stars in 2 companion surveys. One motivation for this study is the fact that strong zodiacal emission can make it hard or impossible to detect planets directly with future observatories like the {\it Terrestrial Planet Finder (TPF)}. The observations reported here exclude a few stars with very high levels of emission, $>$1,000 times the emission of our zodiacal cloud, from direct planet searches. For the remainder of the sample, we set relatively high limits on dust emission from asteroid belt counterparts.
SDSS-IV MANGA: A Star Formation -- Baryonic Mass Relation at Kpc Scales
Creators: name: Barrera-Ballesteros, J. K.
name: Heckman, T.
name: Sanchez, S. F.
name: Drory, N.
name: Cruz-Gonzalez, I.
name: Carigi, L.
name: Riffel, R. A.
name: Boquien, M.
name: Tissera, P.
name: Bizyaev, D.
name: Rong, Y.
name: Boardman, N. F.
name: Hurtado, P. Alvarez
name: team, the MaNGA
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Star formation rate density, $Σ_{\rm SFR}$, has shown a remarkable correlation with both components of the baryonic mass at kpc scales (i.e., the stellar mass density, and the molecular gas mass density; $Σ_{\ast}$, and $Σ_{\rm mol}$, respectively) for galaxies in the nearby Universe. In this study we propose an empirical relation between $Σ_{\rm SFR}$ and the baryonic mass surface density ($Σ_{\rm b}$ =$Σ_{\rm mol,Av}$ + $Σ_{\ast}$; where $Σ_{\rm mol,Av}$ is the molecular gas density derived from the optical extinction, Av) at kpc scales using the spatially-resolved properties of the MaNGA survey - the largest sample of galaxies observed via Integral Field Spectroscopy (IFS, $\sim$ 8400 objects). We find that $Σ_{\rm SFR}$ tightly correlates with $Σ_{\rm b}$. Furthermore, we derive an empirical relation between the $Σ_{\rm SFR}$ and a second degree polynomial of $Σ_{\rm b}$ yielding a one-to-one relation between these two observables. Both, $Σ_{\rm b}$ and its polynomial form show a stronger correlation and smaller scatter with respect to $Σ_{\rm SFR}$ than the relations derived using the individual components of $Σ_{\rm b}$. Our results suggest that indeed these three parameters are physically correlated, suggesting a scenario in which the two components of the baryonic mass regulate the star-formation activity at kpc scales.
description: 10 pages, 6 Figures, accepted for publication in ApJ
Preferential attachment in the growth of social networks: the case of Wikipedia
Creators: name: Capocci, A.
name: Servedio, V. D. P.
name: Colaiori, F.
name: Buriol, L. S.
name: Donato, D.
name: Leonardi, S.
name: Caldarelli, G.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Other Computer Science (cs.OH)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: We present an analysis of the statistical properties and growth of the free on-line encyclopedia Wikipedia. By describing topics by vertices and hyperlinks between them as edges, we can represent this encyclopedia as a directed graph. The topological properties of this graph are in close analogy with that of the World Wide Web, despite the very different growth mechanism. In particular we measure a scale--invariant distribution of the in-- and out-- degree and we are able to reproduce these features by means of a simple statistical model. As a major consequence, Wikipedia growth can be described by local rules such as the preferential attachment mechanism, though users can act globally on the network.
description: 4 pages, 4 figures, revtex
Μελέτη της χωρικής διαφοροποίησης αμπελώνα, με τη χρησιμοποίηση φορητού καταγραφέα της ηλεκτρικής αγωγιμότητας του εδάφους και διερεύνηση μερικών φυσιολογικών παραμέτρων.:
Creators: name: Γκένος, Γεώργιος Σοφοκλή
Publisher: name: Aristotle University of Thessaloniki
Year: 2010
Subjects: Ηλεκτρική αγωγιμότητα εδάφους
Γεωργία Ακριβείας
Ασύρτικο
Electrical conductivity, EC
Precision Agriculture
Site-Specific Management, SSM

description: Βασιζόμενη στις αρχές της Γεωργίας Ακριβείας (Precision Agriculture), η χωρικά διαφοροποιημένη διαχείριση (Site-Specific Management) της αγροτικής παραγωγής (έλεγχος εισροών νερού και λιπασμάτων, προγραμματισμός καλλιεργητικών πρακτικών κλπ ανάλογα με την ετερογένεια του αγρού) έχει ως στόχο τη μεγαλύτερη οικονομική απόδοση και τον περιορισμό των δυσμενών επιπτώσεων για το περιβάλλον και τον άνθρωπο. Στην παρούσα εργασία έγινε μελέτη της χωρικής διαφοροποίησης αμπελώνα 20 στρεμμάτων, φυτεμένου με την ποικιλία Ασύρτικο, με τη χρήση φορητού καταγραφέα της ηλεκτρικής αγωγιμότητας του εδάφους (EC) Veris 2000XA, κατά τη βλαστική περίοδο του 2008. Τα δεδομένα που προέκυψαν από την καταγραφή της ηλεκτρικής αγωγιμότητας του εδάφους κατέδειξαν την ύπαρξη τριών θεωρητικών υπομονάδων διαχείρισης, στις οποίες διερευνήθηκε η επίδραση του εδάφους στις φυσιολογικές διεργασίες της αμπέλου αλλά και στα ποιοτικά γνωρίσματα της παραγωγής. Από την εδαφολογική ανάλυση που ακολούθησε προέκυψε αρνητική συσχέτιση της EC με το ανθρακικό ασβέστιο και το pH του εδάφους, πιθανώς λόγω του ρόλου του ασβεστίου στις φυσικές ιδιότητες του εδάφους. Η μελέτη της φυσιολογίας της αμπέλου επιβεβαίωσε την ύπαρξη ανομοιογένειας στο εσωτερικό του πειραματικού αμπελώνα, που σε μεγάλο βαθμό ταυτίστηκε με τα αποτελέσματα της χωρικής διαφοροποίησης της EC. Στη ζώνη με τη υψηλότερη EC, η ποικιλία Ασύρτικο παρουσίασε σε όλη τη βλαστική περίοδο υψηλότερη στοματική αγωγιμότητα και φωτοσύνθεση, πιθανώς λόγω μεγαλύτερης εδαφικής υγρασίας. Στην ίδια ζώνη, η αύξηση και ανάπτυξη της αμπέλου ήταν μεγαλύτερη από τις άλλες ζώνες.
description: Based on the principles of Precision Agriculture, Site-Specific Management aims to provide a better control of agricultural inputs and assure a better programming of agricultural practices, in order to optimize economic and environmental profit. In the present work, the spatial variation of a 2 ha vineyard planted with cv. Assyrtiko (Vitis vinifera L.) was conducted using a soil electrical conductivity (EC) sensor, Veris 2000XA. Data collected by soil EC measurement showed the existence of three potential management units, in which was studied the effect of soil variability on vine physiology, yield and grape attributes. According to soil analysis, a correlation was found between EC and soil CaCO3 and pH. The vine physiology study confirmed the heterogeneity within the vineyard and mostly coincided with the Veris 2000XA data. In the zone with the higher EC, Assyrtiko showed higher stomatal conductance and photosynthesis during the growth period, probably due to increased soil water content. In the same area, vine growth and productivity was highest among studied zones.