cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Agricultural Shocks and Conflict in the Short- and Long-Term: Evidence from Desert Locust Swarms
Creators: name: Biscaye, Pierre
Publisher: name: Unknown
Year: 2023
Subjects: subject: Agricultural and Food Policy
subject: Crop Production/Industries
subject: Risk and Uncertainty
subject: desert locusts
subject: natural disasters
subject: conflict
subject: agriculture
subject: Africa

description: This paper tests the importance of changes in opportunity costs related to agriculture on the risk of violent conflict using data on locust swarms and conflict collapsed to annual 0.25 (approx. 28km2) grid cell observations across Africa and the Arabian peninsula. The identification exploits exogenous local variation in locust swarm exposure driven by patterns in swarm movements together with weather controls and grid cell and country-by-year fixed effects to identify causal impacts of these agricultural shocks. Locust swarms decrease the likelihood of violent conflict event in a given year by around 20%. Effects are driven by areas with crop and pasture land, and there is no evidence of conflict spillovers to nearby areas. The impacts are largest for swarms that arrive in the off-season or planting season for major crops, based on national crop calendars, and the patterns are not consistent with effects on conflict driven by changes in conflict opportunity costs related to agriculture. This points to the availability of non-agricultural livelihood opportunities and to alternative factors such as psychological impacts and relief efforts less often discussed in this literature as crucial in determining whether an agricultural shock increases conflict risk. In contrast to short term negative effects on conflict, cells affected by the 2003-2005 major desert locust upsurge were 62% more likely to experience any conflict in a given year afterward.Absolute impacts are increasing over time alongside a general increase in conflict in the sample countries, suggesting affected areas are made vulnerable to future shocks which precipitate conflict.
Nature of the non-exponential primary relaxation in structural glass-formers probed by dynamically selective experiments
Creators: name: Böhmer, Roland
name: Chamberlin, R. V.
name: Diezemann, G.
name: Geil, B.
name: Heuer, A.
name: Hinze, G.
name: Kuebler, S. C.
name: Richert, R.
name: Schiener, B.
name: Sillescu, H.
name: Spiess, H. W.
name: Tracht, U.
name: Wilhelm, M.
Publisher: name: Elsevier
Year: 1999
Subjects: subject: 530

description: Several experimental methods feature the potential to distinguish between slow and fast contributions to the non-exponential, ensemble averaged primary response in glass-forming materials. Some of these techniques are based on the selection of subensembles using multi-dimensional nuclear magnetic resonance, optical bleaching, and non-resonant spectral hole burning. Others, such as the time-dependent solvation spectroscopy, measure microscopic responses induced by local perturbations. Using several of these methods it could be demonstrated for various glass-forming materials that the non-exponential relaxation results from a superposition of dynamically distinguishable entities. The experimental observation that subensembles can be selected efficiently indicates a large degree of heterogeneity. The intrinsic response is compatible with single exponential relaxation.
Size effects in the Verwey transition of nanometer-thick micron-wide magnetite crystals
Creators: name: del Campo, Adolfo
name: Ruiz-Gómez, Sandra
name: Trapero, Eva M.
name: Granados-Miralles, Cecilia
name: Quesada, Adrián
name: Foerster, Michael
name: Aballe, Lucía
name: Prieto, José Emilio
name: de la Figuera, Juan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We have monitored the Verwey transition in micrometer-wide, nanometer-thick magnetite islands on epitaxial Ru films on Al2O3(0001) using Raman spectroscopy. The islands have been grown by high-temperature oxygen-assisted molecular beam epitaxy. Below 100 K and for thicknesses above 20 nm the Raman spectra correspond to those observed in bulk crystals and high quality thin films for the sub-Verwey magnetite structure. At room temperature the width of the cubic phase modes is similar to the best reported in bulk crystals, indicating a similar level of electron-phonon interaction. The evolution of the Raman spectra upon cooling suggests that for islands thicker than 20 nm, structural changes appear first at temperatures starting at 150 K and the Verwey transition itself takes place at around 115 K. However, islands thinner than 20 nm show a very different Raman spectra indicating that while a transition takes place, the charge order of the ultrathin islands differs markedly from their thicker counterparts
description: 8 pages, 5 figures, 2 tables
Weakly supervised learning for pattern classification in serial femtosecond crystallography
Creators: name: Xie, Jianan
name: Liu, Ji
name: Zhang, Chi
name: Chen, Xihui
name: Huai, Ping
name: Zheng, Jie
name: Zhang, Xiaofeng
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Machine Learning (cs.LG)
subject: Optics (physics.optics)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Serial femtosecond crystallography at X-ray free electron laser facilities opens a new era for the determination of crystal structure. However, the data processing of those experiments is facing unprecedented challenge, because the total number of diffraction patterns needed to determinate a high-resolution structure is huge. Machine learning methods are very likely to play important roles in dealing with such a large volume of data. Convolutional neural networks have made a great success in the field of pattern classification, however, training of the networks need very large datasets with labels. Th is heavy dependence on labeled datasets will seriously restrict the application of networks, because it is very costly to annotate a large number of diffraction patterns. In this article we present our job on the classification of diffraction pattern by weakly supervised algorithms, with the aim of reducing as much as possible the size of the labeled dataset required for training. Our result shows that weakly supervised methods can significantly reduce the need for the number of labeled patterns while achieving comparable accuracy to fully supervised methods.
description: $\copyright$ 2023 Optica Publishing Group. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved. Link for fulltext: https://opg.optica.org/oe/fulltext.cfm?uri=oe-31-20-32909&id=538502
The ASAS-SN Bright Supernova Catalog $-$ II. 2015
Creators: name: Holoien, T. W. -S.
name: Brown, J. S.
name: Stanek, K. Z.
name: Kochanek, C. S.
name: Shappee, B. J.
name: Prieto, J. L.
name: Dong, Subo
name: Brimacombe, J.
name: Bishop, D. W.
name: Basu, U.
name: Beacom, J. F.
name: Bersier, D.
name: Chen, Ping
name: Danilet, A. B.
name: Falco, E.
name: Godoy-Rivera, D.
name: Goss, N.
name: Pojmanski, G.
name: Simonian, G. V.
name: Skowron, D. M.
name: Thompson, Todd A.
name: Woźniak, P. R.
name: Avíla, C. G.
name: Bock, G.
name: Carballo, J. -L. G.
name: Conseil, E.
name: Contreras, C.
name: Cruz, I.
name: andújar, J. M. F.
name: Guo, Zhen
name: Hsiao, E. Y.
name: Kiyota, S.
name: Koff, R. A.
name: Krannich, G.
name: Madore, B. F.
name: Marples, P.
name: Masi, G.
name: Morrell, N.
name: Monard, L. A. G.
name: Munoz-Mateos, J. C.
name: Nicholls, B.
name: Nicolas, J.
name: Wagner, R. M.
name: Wiethoff, W. S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same information is presented for bright ($m_V\leq17$), spectroscopically confirmed supernovae discovered by other sources in 2015. As with the first ASAS-SN bright supernova catalog, we also present redshifts and near-UV through IR magnitudes for all supernova host galaxies in both samples. Combined with our previous catalog, this work comprises a complete catalog of 455 supernovae from multiple professional and amateur sources, allowing for population studies that were previously impossible. This is the second of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.
description: 16 pages, 6 figures, 4 tables. Submitted to MNRAS. Tables containing the catalog data presented in this submission are included in machine-readable format as ancillary files. Manuscript updated to reflect changes made in the published version and to correct an error in the host galaxy magnitudes presented in Tables 3 and 4. For a brief video explaining this paper, see https://youtu.be/iqYJp1AmyMw
Multiplexed gradient descent: Fast online training of modern datasets on hardware neural networks without backpropagation
Creators: name: McCaughan, Adam N.
name: Oripov, Bakhrom G.
name: Ganesh, Natesh
name: Nam, Sae Woo
name: Dienstfrey, Andrew
name: Buckley, Sonia M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: We present multiplexed gradient descent (MGD), a gradient descent framework designed to easily train analog or digital neural networks in hardware. MGD utilizes zero-order optimization techniques for online training of hardware neural networks. We demonstrate its ability to train neural networks on modern machine learning datasets, including CIFAR-10 and Fashion-MNIST, and compare its performance to backpropagation. Assuming realistic timescales and hardware parameters, our results indicate that these optimization techniques can train a network on emerging hardware platforms orders of magnitude faster than the wall-clock time of training via backpropagation on a standard GPU, even in the presence of imperfect weight updates or device-to-device variations in the hardware. We additionally describe how it can be applied to existing hardware as part of chip-in-the-loop training, or integrated directly at the hardware level. Crucially, the MGD framework is highly flexible, and its gradient descent process can be optimized to compensate for specific hardware limitations such as slow parameter-update speeds or limited input bandwidth.
Nucleus-aware Self-supervised Pretraining Using Unpaired Image-to-image Translation for Histopathology Images
Creators: name: Song, Zhiyun
name: Du, Penghui
name: Yan, Junpeng
name: Li, Kailu
name: Shou, Jianzhong
name: Lai, Maode
name: Fan, Yubo
name: Xu, Yan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Self-supervised pretraining attempts to enhance model performance by obtaining effective features from unlabeled data, and has demonstrated its effectiveness in the field of histopathology images. Despite its success, few works concentrate on the extraction of nucleus-level information, which is essential for pathologic analysis. In this work, we propose a novel nucleus-aware self-supervised pretraining framework for histopathology images. The framework aims to capture the nuclear morphology and distribution information through unpaired image-to-image translation between histopathology images and pseudo mask images. The generation process is modulated by both conditional and stochastic style representations, ensuring the reality and diversity of the generated histopathology images for pretraining. Further, an instance segmentation guided strategy is employed to capture instance-level information. The experiments on 7 datasets show that the proposed pretraining method outperforms supervised ones on Kather classification, multiple instance learning, and 5 dense-prediction tasks with the transfer learning protocol, and yields superior results than other self-supervised approaches on 8 semi-supervised tasks. Our project is publicly available at https://github.com/zhiyuns/UNITPathSSL.
Four-thirds law of energy and magnetic helicity in electron and Hall magnetohydrodynamic fluids
Creators: name: Wang, Yanqing
name: Chkhetiani, Otto
Publisher: name: arXiv
Year: 2023
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: 76F02, 76B99, 35L65, 35L67, 35Q35

description: In this paper, by exploiting the feature of the Hall term, we establish some local version four-thirds laws for the dissipation rates of energy and magnetic helicity in both electron and Hall magnetohydrodynamic equations in the sense of Duchon-Robert type. New 4/3 laws for the dissipation rates of magnetic helicity in these systems are first observed and four-thirds law involving the dissipation rates of energy for the Hall magnetohydrodynamic equations generalizes the work of Galtier.
description: 19 pages
Non-hydrostatic modelling of the wave-induced response of moored floating structures
Creators: name: Rijnsdorp, Dirk Pieter
name: Wolgamot, Hugh
name: Zijlema, Marcel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Predictions of the wave-induced response of floating structures that are moored in a harbour or coastal waters require an accurate description of the (nonlinear) evolution of waves over variable bottom topography, the interactions of the waves with the structure, and the dynamics of the mooring system. In this paper, we present a new advanced numerical model to simulate the wave-induced response of a floating structure that is moored in an arbitrary nearshore region. The model is based on the non-hydrostatic approach, and implemented in the open-source model SWASH, which provides an efficient numerical framework to simulate the nonlinear wave evolution over variable bottom topographies. The model is extended with a solution to the rigid body that is tightly coupled to the hydrodynamic equations. The model was validated for two test cases that consider different floating structures of increasing geometrical complexity: a cylindrical geometry that is representative of a wave-energy-converter, and a vessel with a more complex shaped hull. A range of wave conditions were considered, varying from monochromatic to short-crested sea states. Model predictions of the excitation forces, added mass, radiation damping, and the wave-induced response agreed well with benchmark solutions to the potential flow equations. Besides the response to the primary wave (sea-swell) components, the model was also able to capture the second-order difference-frequency forcing and response of the moored vessel. Importantly, the model captured the wave-induced response with a relatively coarse vertical resolution, allowing for applications at the scale of a realistic harbour or coastal region. The proposed model thereby provides a new tool to seamlessly simulate the nonlinear evolution of waves over complex bottom topography and the wave-induced response of a floating structure that is moored in coastal waters.
Applying the relativistic quantization condition to a three-particle bound state in a periodic box
Creators: name: Hansen, Maxwell T.
name: Sharpe, Stephen R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Using our recently developed relativistic three-particle quantization condition, we study the finite-volume energy shift of a spin-zero three-particle bound state. We reproduce the result obtained using non-relativistic quantum mechanics by Meissner, Rios and Rusetsky, and generalize the result to a moving frame.
description: 20 pages, no figures, v2: fixed issues with special characters in references, v3: minor rewording, version appearing in PRD
Multi-scale Imaging of Nuclear Deformation at the Electron Ion Collider
Creators: name: Mäntysaari, Heikki
name: Schenke, Björn
name: Shen, Chun
name: Zhao, Wenbin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We show within the Color Glass Condensate framework that exclusive vector meson production at high energy is sensitive to the geometric deformation of the target nucleus at multiple length scales. Studying $e+$U collisions and varying the deformation of the uranium target, we demonstrate that larger deformations result in enhanced incoherent vector meson production cross sections. Further, different multipole deformation parameters affect different regions of transverse momentum transfer. Employing JIMWLK evolution to study the Bjorken-$x$ dependence of our results, we find that the ratio of incoherent to coherent cross sections decreases with decreasing $x$, largely independently of the quadrupole deformation of the target. Comparing results for the same process using ${\rm {^{20}Ne}}$ targets with ${\rm {^{16}O}}$ targets, we find that differences in deformation are clearly visible in the incoherent cross section. These findings show that certain observables at the Electron-Ion Collider are very sensitive to nuclear structure. Consequently, deformations need to be taken into account when interpreting experimental results. More importantly, this also means that $\vert t\vert$-differential diffractive vector meson production could become a powerful tool, enabling the most direct measurements of nuclear structure at different length scales, ranging from nuclear deformation at low $\vert t\vert$ to nucleon- and subnucleon-size scales at higher $\vert t\vert$.
A Nearly Naked Supermassive Black Hole
Creators: name: Condon, J. J.
name: Darling, Jeremy
name: Kovalev, Y. Y.
name: Petrov, L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: During a systematic search for supermassive black holes (SMBHs) not in galactic nuclei, we identified the compact symmetric radio source B3 1715+425 with an emission-line galaxy offset ~ 8.5 kpc from the nucleus of the brightest cluster galaxy (BCG) in the redshift $z = 0.1754$ cluster ZwCl 8193. B3 1715+425 is too bright (brightness temperature $\sim 3 \times 10^{10}$ K at observing frequency 7.6 GHz) and too luminous (1.4 GHz luminosity $\sim 10^{25}$ W/Hz) to be powered by anything but a SMBH, but its host galaxy is much smaller ($\sim 0.9$ kpc $\times$ 0.6 kpc full width between half-maximum points) and optically fainter (R-band absolute magnitude $\sim -18.2$) than any other radio galaxy. Its high radial velocity $\sim 1860$ km/s relative to the BCG, continuous ionized wake extending back to the BCG nucleus, and surrounding debris indicate that the radio galaxy was tidally shredded passing through the BCG core, leaving a nearly naked supermassive black hole fleeing from the BCG with space velocity $> 2000$ km/s. The radio galaxy has mass $< 6 \times 10^9$ solar masses and infrared luminosity $\sim 3 \times 10^{11}$ solar luminosities close to its dust Eddington limit, so it is vulnerable to further mass loss from radiative feedback.
description: 8 pages, 12 figures. Revised version, accepted for publication in ApJ
Lepton number violation in 331 models
Creators: name: Fonseca, Renato M.
name: Hirsch, Martin
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Different models based on the extended $SU(3)_{C}\times SU(3)_{L}\times U(1)_{X}$ (331) gauge group have been proposed over the past four decades. Yet, despite being an active research topic, the status of lepton number in 331 models has not been fully addressed in the literature, and furthermore many of the original proposals can not explain the observed neutrino masses. In this paper we review the basic features of various 331 models, focusing on potential sources of lepton number violation. We then describe different modifications which can be made to the original models in order to accommodate neutrino (and charged lepton) masses.
description: Matches the version published in Physical Review D
A Study of the Role of Assets Disclosure and Registration Law Procl.No 668/2010 in Reducing Corruption: the Case of FEACC .
Creators: name: Alemayehu, Bekuretsion
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: The main objective of this study is to identify the role of Assets Disclosure and Registration law in the reduction of corruption through the Federal Ethics and Anti-Corruption Commission of Ethi- opia. The introduction and implementation of the Assets Disclosure and Registration law by the Federal Ethics and Anti-Corruption Commission of Ethiopia is believed to be beneficial for the Country in preventing and combating corruption. In order to achieve the research objective, the researcher gathered data through questionnaires, interviews, and documents analysis. Then, the researcher analyzed and interpreted the data; drew conclusions; and put forward recommenda- tions. The major findings include: the commission has scored consistently and in increasingly rate better than the predeceased and period of pre-promulgation years ADR in corruption pre- vention activities, Allegations Received, Cases Investigated, Charges filed against suspects, Number of Individuals Arrested, Number of convictions in terms of files, Conviction Rate in terms of files (%), Individuals Convicted, and assets recovered lost to corruption by the commission. Effectiveness of the commission increases and level of corruption perception index decreased at steady level and increase cleanness of corruption or reduced corruption committing in the coun- try. Even though the law has a very great role in maximizing efforts of fighting corruption in the case of FEACC, there is a lack of full utilization of the law as wanted especially conscious verifi- cation. To alleviate the problem it is recommended that the Commission should be at full scale engagement to increase the conscious verification of the already registered assets so as to achieve the very goal of assets disclosure and registration law
High-Energy Neutrino Emission from White Dwarf Mergers
Creators: name: Xiao, Di
name: Mészáros, Peter
name: Murase, Kohta
name: Dai, Zi-gao
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The merger of two white dwarfs is expected to result in a central fast rotating core surrounded by a debris disk, in which magnetorotational instabilities give rise to a hot magnetized corona and a magnetized outflow. The dissipation of magnetic energy via reconnection could lead to the acceleration of cosmic-rays in the expanding material, which would result in high energy neutrinos. We discuss the possibility of using these neutrino signals as probes of the outflow dynamics, magnetic energy dissipation rate and cosmic-ray acceleration efficiency. Importantly, the accompanying high-energy gamma-rays are absorbed within these sources because of the large optical depth, so these neutrino sources can be regarded as hidden cosmic-ray accelerators that are consistent with the non-detection of gamma-rays with Fermi-LAT. While the cosmic-ray generation rate is highly uncertain, if it reaches $\sim10^{45}\,\rm erg\,Mpc^{-3}\,yr^{-1}$, the diffuse neutrino flux could contribute a substantial fraction of the IceCube observations. We also evaluate the prospect of observing individual merger events, which provides a means for testing such sources in the future.
description: 8 pages, 6 figures, ApJ accepted
Spontaneous off-stoichiometry as the knob to control dielectric properties of gapped metals
Creators: name: Khan, Muhammad Rizwan
name: Gopidi, Harshan Reddy
name: Darabian, Hamid Reza
name: Pawlak, Dorota A.
name: Malyi, Oleksandr I.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using the first-principles calculations and La3Te4 as an example of an n-type gapped metal, we demonstrate that gapped metals can develop spontaneous defect formation resulting in off-stoichiometric compounds. Importantly, these compounds have different free carrier concentrations and can be realized by optimizing synthesis conditions. The ability to manipulate the free carrier concentration allows to tailor intraband and interband transitions, thus controlling the optoelectronic properties of materials in general. Specifically, by realizing different off-stochiometric La3-xTe4 compounds, it is possible to reach specific crossings of the real part of the dielectric function with the zero line, reduce plasma frequency contribution to absorption spectra, or, more generally, induce metal-to-insulator transition. This is particularly important in the context of optoelectronic, plasmonic, and epsilon-near-zero materials, as it enables materials design with a target functionality. While this work is limited to the specific gapped metal, we demonstrate that the fundamental physics is transferable to other gapped metals and can be generally used to design a wide class of new optoelectronic/plasmonic materials.
description: 3
Black hole perturbations in higher-order scalar-tensor theories: initial value problem and dynamical stability
Creators: name: Nakashi, Keisuke
name: Kimura, Masashi
name: Motohashi, Hayato
name: Takahashi, Kazufumi
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We propose a physically sensible formulation of initial value problem for black hole perturbations in higher-order scalar-tensor theories. As a first application, we study monopole perturbations around stealth Schwarzschild solutions in a shift- and reflection-symmetric subclass of degenerate higher-order scalar-tensor (DHOST) theories. In particular, we investigate the time evolution of the monopole perturbations by solving a two-dimensional wave equation and analyze the Vishveshwara's classical scattering experiment, i.e., the time evolution of a Gaussian wave packet. As a result, we confirm that stealth Schwarzschild solutions in the DHOST theory are dynamically stable against the monopole perturbations with the wavelength comparable or shorter than the size of the black hole horizon. We also find that the damped oscillations at the late time do not show up unlike the ringdown phase in the standard case of general relativity. Moreover, we investigate the characteristic curves of the monopole perturbations as well as a static spherically symmetric solution with monopole hair.
description: 35 pages, 13 figures, v2: published version in CQG
Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in the NiCl2-4SC(NH2)2 compound
Creators: name: Blinder, Rémi
name: Dupont, Maxime
name: Mukhopadhyay, Sutirtha
name: Grbić, Mihael S.
name: Laflorencie, Nicolas
name: Capponi, Sylvain
name: Mayaffre, Hadrien
name: Berthier, Claude
name: Paduan-Filho, Armando
name: Horvatić, Mladen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Nuclear magnetic resonance (NMR) study of the high magnetic field (H) part of the Bose-Einstein condensed (BEC) phase of the quasi-onedimensional (quasi-1D) antiferromagnetic quantum spin-chain compound NiCl2-4SC(NH2)2 (DTN) was performed. We precisely determined the phase boundary, Tc(H), down to 40 mK; the critical boson density, n_c(Tc); and the absolute value of the BEC order parameter S_perp at very low temperature (T = 0.12 K). All results are accurately reproduced by numerical quantum Monte Carlo simulations of a realistic three-dimensional (3D) model Hamiltonian. Approximate analytical predictions based on the 1D Tomonaga-Luttinger liquid description are found to be precise for Tc(H), but less so for S_perp(H), which is more sensitive to the strength of 3D couplings, in particular close to the critical field. A mean-field treatment, based on the Hartree-Fock-Popov description, is found to be valid only up to n_c = 4% (T < 0.3 K), while for higher n_c boson interactions appear to modify the density of states.
description: Manuscript (6 pages, 3 figures) and the corresponding Supplemental material (5 pages, 6 figures), altogether 11 pages and 9 figures
Can gravitational vacuum condensate stars be a dark energy source?
Creators: name: Avelino, P. P.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Gravitational vacuum condensate stars, also known as gravastars, have been proposed as an alternative to black holes. Their interior contains a perfect fluid with an equation of state akin to that of a cosmological constant. For this reason, they have recently been considered as a possible astrophysical source of dark energy. In this work we argue that gravitational vacuum condensate stars cannot be the source of dark energy and highlight that a direct coupling of their mass to the dynamics of the Universe would lead to an additional velocity dependent acceleration, damping their motion with respect to the cosmological frame. We briefly discuss the potential impact of this additional acceleration in the context of a recent proposal that the observed mass growth of compact objects at the core of elliptical galaxies might result from such a cosmological coupling.
description: 4 pages
Elastic properties of a Sc-Zr-Nb-Ta-Rh-Pd high-entropy alloy superconductor
Creators: name: Pan, Yupeng
name: He, Xiaobo
name: Zhou, Binjie
name: Strong, Denver
name: Zhang, Jian
name: Yu, Hai-Bin
name: Tan, Yunfei
name: Cava, Robert J.
name: Luo, Yongkang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report a comprehensive study on the elastic properties of a hexanary high-entropy alloy superconductor (ScZrNbTa)$_{0.685}$[RhPd]$_{0.315}$ at room and cryogenic temperatures, by Resonant Ultrasound Spectroscopy experiments. The derived elastic constants are bulk modulus $K=132.7$ GPa, Young's modulus $E=121.0$ GPa, shear modulus $G=44.9$ GPa, and Poisson's ratio $ν$=0.348 for room temperature. The Young's and shear moduli are $\sim 10\%$ larger than those in NbTi superconductor with similar $T_c$, while the ductility is comparable. Moreover, the mechanical performance is further enhanced at cryogenic temperature. Our work confirms the advantageous mechanical properties of high-entropy alloy superconductors and suggests the application prospects.
description: 11 pages, 3 figures, 1 table
Discovery and inference of a causal network with hidden confounding
Creators: name: Chen, Li
name: Li, Chunlin
name: Shen, Xiaotong
name: Pan, Wei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: This article proposes a novel causal discovery and inference method called GrIVET for a Gaussian directed acyclic graph with unmeasured confounders. GrIVET consists of an order-based causal discovery method and a likelihood-based inferential procedure. For causal discovery, we generalize the existing peeling algorithm to estimate the ancestral relations and candidate instruments in the presence of hidden confounders. Based on this, we propose a new procedure for instrumental variable estimation of each direct effect by separating it from any mediation effects. For inference, we develop a new likelihood ratio test of multiple causal effects that is able to account for the unmeasured confounders. Theoretically, we prove that the proposed method has desirable guarantees, including robustness to invalid instruments and uncertain interventions, estimation consistency, low-order polynomial time complexity, and validity of asymptotic inference. Numerically, GrIVET performs well and compares favorably against state-of-the-art competitors. Furthermore, we demonstrate the utility and effectiveness of the proposed method through an application inferring regulatory pathways from Alzheimer's disease gene expression data.
description: 27 pages, 4 figures, 3 tables. The manuscript is accepted by Journal of the American Statistical Association
Teaching Functional Patterns through Robotic Applications
Creators: name: Boender, J.
name: Currie, E.
name: Loomes, M.
name: Primiero, G.
name: Raimondi, F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computers and Society (cs.CY)
subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: We present our approach to teaching functional programming to First Year Computer Science students at Middlesex University through projects in robotics. A holistic approach is taken to the curriculum, emphasising the connections between different subject areas. A key part of the students' learning is through practical projects that draw upon and integrate the taught material. To support these, we developed the Middlesex Robotic plaTfOrm (MIRTO), an open-source platform built using Raspberry Pi, Arduino, HUB-ee wheels and running Racket (a LISP dialect). In this paper we present the motivations for our choices and explain how a number of concepts of functional programming may be employed when programming robotic applications. We present some students' work with robotics projects: we consider the use of robotics projects to have been a success, both for their value in reinforcing students' understanding of programming concepts and for their value in motivating the students.
description: In Proceedings TFPIE 2015/6, arXiv:1611.08651
SILOP: An Automated Framework for Semantic Segmentation Using Image Labels Based on Object Perimeters
Creators: name: Ostrowski, Erik
name: Prabakaran, Bharath Srinivas
name: Shafique, Muhammad
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Achieving high-quality semantic segmentation predictions using only image-level labels enables a new level of real-world applicability. Although state-of-the-art networks deliver reliable predictions, the amount of handcrafted pixel-wise annotations to enable these results are not feasible in many real-world applications. Hence, several works have already targeted this bottleneck, using classifier-based networks like Class Activation Maps~\cite{CAM} (CAMs) as a base. Addressing CAM's weaknesses of fuzzy borders and incomplete predictions, state-of-the-art approaches rely only on adding regulations to the classifier loss or using pixel-similarity-based refinement after the fact. We propose a framework that introduces an additional module using object perimeters for improved saliency. We define object perimeter information as the line separating the object and background. Our new PerimeterFit module will be applied to pre-refine the CAM predictions before using the pixel-similarity-based network. In this way, our PerimeterFit increases the quality of the CAM prediction while simultaneously improving the false negative rate. We investigated a wide range of state-of-the-art unsupervised semantic segmentation networks and edge detection techniques to create useful perimeter maps, which enable our framework to predict object locations with sharper perimeters. We achieved up to 1.5% improvement over frameworks without our PerimeterFit module. We conduct an exhaustive analysis to illustrate that SILOP enhances existing state-of-the-art frameworks for image-level-based semantic segmentation. The framework is open-source and accessible online at https://github.com/ErikOstrowski/SILOP.
description: Accepted for Publication at the International Joint Conference on Neural Networks (IJCNN), July 2023, Gold Coast, Queensland, Australia
Adapting SnapDx Platform For Low-Cost, Electricity-Free Molecular Amplification Based Detection of Schistosomiasis in LMIC Settings
Creators: name: Mittal, Smiti
Publisher: name: Stanford Digital Repository
Year: 2023
Subjects: subject: Global Health
subject: Bioengineering--Research
subject: Molecular Amplification
subject: Schistosomiasis--Diagnosis
subject: Point-of-care testing

description: Schistosomiasis, caused by parasitic worms, is a neglected tropical disease affecting nearly 240 million people globally. The World Health Organization released a Target Product Profile in 2021 calling for the development of new diagnostics for monitoring and evaluation of Schistosomiasis, to move towards elimination. Traditional diagnostics using microscopy are reliant on laboratory infrastructure and technician skill. They also lack sufficient sensitivity and specificity. This thesis develops a loop-mediated isothermal amplification (LAMP) direct from urine Schistosomiasis assay for translation onto SnapDx platform, an electricity-free, point-of-care nucleic-acid diagnostics platform developed in the Prakash Lab for respiratory infections like Sars-CoV-2 detection. Here we demonstrate that the current version of the assay with genomic DNA from Schistosomiasis spiked in human urine in controlled lab settings displays a sensitivity of 77.50% at 1 ng/uL and 62.50% at 100 pg/uL and a specificity of 97.5% - all read via a simple colorimetric readout, in Eppendorf tubes. We further test the impact of various sample preparation methods on the assay. The lowest limit of detection reached on simulated urine samples is 1 pg/uL using samples purified with MidiPrep prior to the introduction of genomic DNA. We further find 11% of all the reactions run showing differing results between fluorescence and colorimetric readout. The mismatch is found to be greater at lower sample concentrations. Next we report on testing the functionality of the assay with wet bath inactivation and run, as required in the electricity-free SnapDx usage in field context. In future work, we intend to investigate different primer combinations, urine-based reaction inhibitors, and compact, low-cost sample preparation methods (such as urine egg concentration) are required to further optimize the assay. Next,  reliability, sensitivity, specificity and limit of detection will need to be evaluated with real patient samples. Our work lays the foundation for the future implementation of this assay in field conditions without electricity, opening the door to molecular based surveillance approaches , which satisfies the usability and infrastructure requirements of the World Health Organization’s Target Product Profile. It also contributes to a body of work aiming to develop SnapDx applications for a wide range of infectious diseases, compatible with urine, saliva, blood, and other biological fluids.
Proton Stability: From the Standard Model to Beyond Grand Unification
Creators: name: Wang, Juven
name: Wan, Zheyan
name: You, Yi-Zhuang
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A proton is known for its longevity, but what is its lifetime? While many Grand Unified Theories predict the proton decay with a finite lifetime, we show that the Standard Model (SM) and some versions of Ultra Unification (which replace sterile neutrinos with new exotic gapped/gapless sectors, e.g., topological or conformal field theory under global anomaly cancellation constraints) with a discrete baryon plus lepton symmetry permit a stable proton. For the 4d SM with $N_f$ families of 15 or 16 Weyl fermions, in addition to the continuous baryon minus lepton U(1)$_{\bf B - L}$ symmetry, there is also a compatible discrete baryon plus lepton $\mathbb{Z}_{2N_f, \bf B + L}$ symmetry. The $\mathbb{Z}_{2N_f, \bf B + L}$ is discrete due to the ABJ anomaly under the BPST SU(2) instanton. Although both U(1)$_{\bf B - L}$ and $\mathbb{Z}_{2N_f, \bf B + L}$ symmetries are anomaly-free under the dynamical SM gauge field, it is important to check whether they have mixed anomalies with the gravitational background field and higher symmetries (whose charged objects are Wilson electric or 't Hooft magnetic line operators) of SM. We can also replace the U(1)$_{\bf B - L}$ with a discrete variant $\mathbb{Z}_{4,X}$ for $X \equiv 5({\bf B - L})-\frac{2}{3} {\tilde Y}$ of electroweak hypercharge ${\tilde Y}$. We explore a systematic classification of candidate perturbative local and nonperturbative global anomalies of the 4d SM, including all these gauge and gravitational backgrounds, via a cobordism theory, which controls the SM's deformation class. We discuss the proton stability of the SM and Ultra Unification in the presence of discrete ${\bf B + L}$ symmetry protection, in particular (U(1)$_{\bf B - L} \times \mathbb{Z}_{2N_f,\bf B + L})/{\mathbb{Z}_2^{\rm F}}$ or $(\mathbb{Z}_{4,X} \times \mathbb{Z}_{2N_f, \bf B + L})/{\mathbb{Z}_2^{\rm F}}$ symmetry with the fermion parity $\mathbb{Z}_2^{\rm F}$.
description: 6 pages. Sequel to arXiv:2112.14765. v2: refinement. Related talks: https://www.youtube.com/results?search_query=cobordism+deformation+standard+model+crticiality. The original title "Proton Stability: From the Standard Model to Ultra Unification" is adjusted in PRD
The Origin of Weak Lensing Convergence Peaks
Creators: name: Liu, Jia
name: Haiman, Zoltan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on $Ω_m$ and $σ_8$ are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational data from the 154 deg$^2$ Canada-France-Hawaii Telescope Lensing Survey. We found that while high peaks (with height $κ$ >3.5 $σ_κ$, where $σ_κ$ is the r.m.s. of the convergence $κ$) are typically due to one single massive halo of ~$10^{15}M_\odot$, low peaks ($κ$ ~ their virial radii), compared with ~0.25 virial radii for halos linked with high peaks, hinting that low peaks are more immune to baryonic processes whose impact is confined to the inner regions of the dark matter halos. Our findings are in good agreement with results from the simulation work by Yang el al. (2011).
description: 10 pages, 10 figures; v2 matches PRD accepted version, results unchanged
Beitrag partizipativer Aspekte der Arbeitsgestaltung und des Wissensaustausches zum Innovationserfolg
Creators: name: Klippert, Jürgen
name: Wölk, Monique
name: Potzner, Christiane
Publisher: name: Lucius & Lucius Verlagsgesellschft GmbH
Year: 2009
Subjects: subject: 300
subject: 650

description: Der Beitrag stellt die Ergebnisse der zweiten Phase eines Forschungsprojektes dar, das den Zusammenhang zwischen Innovationserfolg und direkten sowie repräsentativen Partizipationsmöglichkeiten von Beschäftigten in Unternehmen untersucht. In der Basiserhebung (n=529) wurde der grundsätzliche Zusammenhang zwischen Partizipationsmöglichkeiten und Innovationserfolgen bereits statistisch signifikant nachgewiesen. Im vorliegenden Beitrag wird der Wirkungszusammenhang, den Partizipation sowie beteiligungsorientierter Wissens- und Informationsaustausch bilden, anhand einer Befragung von Beschäftigtenvertretungen (n=51) aus den Unternehmen die auf die Basisbefragung geantwortet haben, näher analysiert. Es wird ein Modell des Wirkungszusammenhangs Partizipation und Innovation entwickelt, das die Faktoren "Handlungs- und Entscheidungsspielräume", "Kooperationsintensität zwischen Betriebsrat und Unternehmensleitung", "Umgang mit Wissen" und "Durchlässigkeit von Wissen im Betrieb" berücksichtigt.
description: Arbeit
High order spatial discretization for variational time implicit schemes: Wasserstein gradient flows and reaction-diffusion systems
Creators: name: Fu, Guosheng
name: Osher, Stanley
name: Li, Wuchen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Numerical Analysis (math.NA)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We design and compute first-order implicit-in-time variational schemes with high-order spatial discretization for initial value gradient flows in generalized optimal transport metric spaces. We first review some examples of gradient flows in generalized optimal transport spaces from the Onsager principle. We then use a one-step time relaxation optimization problem for time-implicit schemes, namely generalized Jordan-Kinderlehrer-Otto schemes. Their minimizing systems satisfy implicit-in-time schemes for initial value gradient flows with first-order time accuracy. We adopt the first-order optimization scheme ALG2 (Augmented Lagrangian method) and high-order finite element methods in spatial discretization to compute the one-step optimization problem. This allows us to derive the implicit-in-time update of initial value gradient flows iteratively. We remark that the iteration in ALG2 has a simple-to-implement point-wise update based on optimal transport and Onsager's activation functions. The proposed method is unconditionally stable for convex cases. Numerical examples are presented to demonstrate the effectiveness of the methods in two-dimensional PDEs, including Wasserstein gradient flows, Fisher--Kolmogorov-Petrovskii-Piskunov equation, and two and four species reversible reaction-diffusion systems.
Paul Fuchs-Frohnhofen (hg.): Arbeitsorientierte Modernisierung. Konzept, Umsetzung, Praxisbeispiele. Mit Vorworten von Walter Haas, DGB-Landesvorsitzender NRW, und Karlheinz Bastong, Landesvereinigung der Arbeitgeberverbände NRW, München/Merin: Rainer Hampp Verlag, 2002, ISBN 3-87988-710-1, iv, VI u. 366 S., Euro 32,80
Creators: name: Bierfreund, Barbara
Publisher: name: Lucius & Lucius Verlagsgesellschaft
Year: 2003
Subjects: subject: 300
subject: 650

description: Arbeit
Peter Brödner, Matthias Knuth (Hg.): Nachhaltige Arbeitsgestaltung. Trendreports zur Entwicklung und Nutzung von Humanressourcen, Bilanzierung innovativer Arbeitsgestaltung Bd. 3, München Mering: Rainer Hampp Verlag, 2002, ISBN 3-87988-663-6, 2002, 552 S., Euro 39,80
Creators: name: Beese, Birgit
Publisher: name: Lucius & Lucius Verlagsgesellschaft
Year: 2004
Subjects: subject: 300
subject: 650

description: Arbeit