cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Superconductivity and magnetic and transport properties of single-crystalline CaK(Fe$_{1-x}$Cr$_{x}$)$_{4}$As$_{4}$
Creators: name: Xu, M.
name: Schmidt, J.
name: Tanatar, M. A.
name: Prozorov, R.
name: Bud'ko, S. L.
name: Canfield, P. C.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Members of the CaK(Fe$_{1-x}$Cr$_{x}$)$_{4}$As$_{4}$ series have been synthesized by high-temperature solution growth in single crystalline form and characterized by X-ray diffraction, elemental analysis, magnetic and transport measurements. The effects of Cr substitution on the superconducting and magnetic ground states of CaKFe$_4$As$_4$ ($T_c$ = 35 K) have been studied. These measurements show that the superconducting transition temperature decreases monotonically and is finally suppressed below 1.8 K as $x$ is increased from 0 to 0.038. The magnetic transition temperature increases in a roughly linear manner as Cr substitution increases. A temperature-composition (\textit{T}-\textit{x}) phase diagram is constructed, revealing a half-dome of superconductivity with the magnetic transition temperature, $T^*$, appearing near 22~K for $x$ $\sim$ 0.017 and rising slowly up to 60~K for $x$ $\sim$ 0.077. The $T$-$x$ phase diagrams for CaK(Fe$_{1-x}$$T$$_{x}$)$_4$As$_4$ for $T$ = Cr and Mn are essentially the same despite the nominally different band filling; this is in marked contrast to $T$ = Co and Ni series for which the $T$-$x$ diagrams scale by a factor of two, consistent with the different changes in band filling Co and Ni would produce when replacing Fe. Superconductivity of CaK(Fe$_{1-x}$Cr$_{x}$)$_{4}$As$_{4}$ is also studied as a function of magnetic field. A clear change in $H^\prime_{c2}$($T$)/$T_c$, where $H^\prime_{c2}$($T$) is d$H_{c2}$($T$)/d$T$, at $x$ $\sim$ 0.012 is observed and probably is related to change of the Fermi surface due to magnetic order. Coherence length and the London penetration depths are also calculated based on $H_{c1}$ and $H_{c2}$ data. Coherence lengths as the function of $x$ also shows changes near $x$ = 0.012, again consistent with Fermi surfaces changes associated with the magnetic ordering seen for higher $x$-values.
description: This work uses the same synthesis and measurements methods to systematicly analysis Cr1144 as our previous work arXiv:2204.10925 (existence of the text overlap) but gives the clear proof of the bi-modal response to electron and hole doping in Fe-based superconductors
The degree of 5f electron localization in URu2Si2: electron energy-loss spectroscopy and spin-orbit sum rule analysis
Creators: name: Jeffries, J. R.
name: Moore, K. T.
name: Butch, N. P.
name: Maple, M. B.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We examine the degree of 5f electron localization in URu2Si2 using spin-orbit sum rule analysis of the U N4,5 (4d \to 5f) edge. When compared to α-U metal, US, USe, and UTe, which have increasing localization of the 5f states, we find that the 5f states of URu2Si2 are more localized, although not entirely. Spin-orbit analysis shows that intermediate coupling is the correct angular momentum coupling mechanism for URu2Si2 when the 5f electron count is between 2.6 and 2.8. These results have direct ramifications for theoretical assessment of the hidden order state of URu2Si2, where the degree of localization of the 5f electrons and their contribution to the Fermi surface are critical.
description: 5 pages, 2 figures
High Pressure and Temperature Neural Network Reactive Force Field for Energetic Materials
Creators: name: Hamilton, Brenden W.
name: Yoo, Pilsun
name: Sakano, Michael N.
name: Islam, Md Mahbubul
name: Strachan, Alejandro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Reactive force fields for molecular dynamics have enabled a wide range of studies in numerous material classes. These force fields are computationally inexpensive as compared to electronic structure calculations and allow for simulations of millions of atoms. However, the accuracy of traditional force fields is limited by their functional forms, preventing continual refinement and improvement. Therefore, we develop a neural network based reactive interatomic potential for the prediction of the mechanical, thermal, and chemical response of energetic materials at extreme conditions for energetic materials. The training set is expanded in an automatic iterative approach and consists of various CHNO materials and their reactions under ambient and under shock loading conditions. This new potential shows improved accuracy over the current state of the art force fields for a wide range of properties such as detonation performance, decomposition product formation, and vibrational spectra under ambient and shock loading conditions.
Parallel synthesis of small molecule compound libraries : isoform selective Rho-Kinase inhibitors
Creators: name: Mohamed, Safwat
Publisher: name: University of British Columbia
Year: 2015

description: The objective of this thesis was to use parallel synthesis to build small molecule libraries of novel compounds with potential as isoform selective type II rho-kinase (ROCK1/2) inhibitors. Considerable effort is ongoing to identify isoform selective ROCK inhibitors, as hyperactivity of the ROCK is implicated in cardiovascular diseases, cancer, diabetes and many other diseases that affect millions of Canadians, and billions of people worldwide. In the absence the extensive structural details of the type II kinase inhibitor binding mode, we have used an empirical approach to the design of type II ROCK inhibitors, based on the conception that such molecules correspond to elongated structures with H-bonding functional elements in their central portion, a motif at one end that mimics the adenine ring in ATP, and a hydrophobic moiety at the other end of the molecule that will interact with an allosteric pocket in the ATP binding region of the kinase. Based on these very general structural requirements, eleven different representative libraries of novel compounds (not described in CAS) were designed and synthesized. In the initial series of compounds, a 2-pyridinone motif was employed as the hinge binding element, and the central portion corresponded to carboxamide substituted oxazoline, oxadiazole, or 2-aminothiazole system, joined through the amide bond to a set of structurally diverse aromatic, heteroaromatic and benzylamine subunits, corresponding to the diversity elements. The preliminary assay results demonstrated that, overall, these compounds were weak and non-selective ROCK1/2 inhibitors when compared to H-1152 as a positive control at 10 μM concentration. However, further structural modification revealed the interest in using an indazole motif as the hinge binder in conjunction with the 2-aminothiazole carboxamide linker. Indeed, more potent activities were observed in the single point assay for a significant portion of the libraries of molecules built around these structural components. Further evaluation of 18 active compounds in a 10-point assay, by Invitrogen, to determine IC50’s revealed that indazole-based inhibitors are active at low micromolar concentrations (1-10 µM), but do not display any significant isoform selectivity.
Innovative Speech-Based Deep Learning Approaches for Parkinson's Disease Classification: A Systematic Review
Creators: name: van Gelderen, Lisanne
name: Tejedor-García, Cristian
Publisher: name: arXiv
Year: 2024
Subjects: subject: Sound (cs.SD)
subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Parkinson's disease (PD), the second most prevalent neurodegenerative disorder worldwide, frequently presents with early-stage speech impairments. Recent advancements in Artificial Intelligence (AI), particularly deep learning (DL), have significantly enhanced PD diagnosis through the analysis of speech data. Nevertheless, the progress of research is restricted by the limited availability of publicly accessible speech-based PD datasets, primarily due to privacy concerns. The goal of this systematic review is to explore the current landscape of speech-based DL approaches for PD classification, based on 33 scientific works published between January 2020 and March 2024. We discuss their available resources, capabilities, and potential limitations, and issues related to bias, explainability, and privacy. Furthermore, this review provides an overview of publicly accessible speech-based datasets and open-source material for PD. The DL approaches identified are categorized into end-to-end (E2E) learning, transfer learning (TL), and deep acoustic feature extraction (DAFE). Among E2E approaches, Convolutional Neural Networks (CNNs) are prevalent, though Transformers are increasingly popular. E2E approaches face challenges such as limited data and computational resources, especially with Transformers. TL addresses these issues by providing more robust PD diagnosis and better generalizability across languages. DAFE aims to improve the explainability and interpretability of results by examining the specific effects of deep features on both other DL approaches and more traditional machine learning (ML) methods. However, it often underperforms compared to E2E and TL approaches.
description: van Gelderen, L., & Tejedor-Garc\'ia, C. (2024). Innovative Speech-Based Deep Learning Approaches for Parkinson's Disease Classification: A Systematic Review. Applied Sciences, 14(17). doi:10.3390/app14177873 This research was funded by the NWO research programme NGF AiNed Fellowship Grants under the project Responsible AI for Voice Diagnostics (RAIVD) - grant number NGF.1607.22.013
Making Parasite-Host Associations Visible using Global Biotic Interactions
Creators: name: Sullivan, Kathryn
name: Poelen, Jorrit H.
name: Seltmann, Katja C.
name: Zaspel, Jennifer M.
Publisher: name: Zenodo
Year: 2021
Subjects: biotic associations, biodiversity informatics, ecological informatics, natural history collections, parasites, host, vectors, disease

description: Publication includes abstract, poster, audio, and audio transcription related to: Biodiversity Digitization: Celebrating a decade of progress Virtual Event 22-23 September, 2021 Organized by iDigBio, Smithsonian's National Museum of Natural History, and GBIF. https://www.idigbio.org/content/biodiversity-digitization-2021 Abstract
 The Terrestrial Parasite Tracker (TPT) Network digitizes and aggregates arthropod parasite collections to build an easily accessible, comprehensive database of parasite-host associations and vector distributions. TPT is working to digitally provide information on parasite collections by providing research-ready data and images from 1.2+ million parasite specimens, which will be accessible to scientists, educators, wildlife managers, and policy makers worldwide.
 Our network is providing needed baseline information for research and management of the ecological interactions among parasites, pathogens, and their hosts in North America (including the U.S. & territories) through Global Biotic Interactions (GloBI) data integration, and data review services. Global Biotic Interactions (GloBI) is an open data integration platform that continually indexes existing openly available species interaction datasets, literature, and specimen records using open source software. Since its inception in 2013, GloBI has grown to be the largest registry of biotic interaction claims, indexing over 8 million interaction claims sourced from hundreds of data sources and citing millions of references. For TPT, GloBI is used to keep track of availability of valuable evidence-based parasite-host interaction claims sourced from participating Natural History Collections as well as facilitating in-depth data reviews to help improve, and sometimes align, data exchange protocols (aka, integration profiles).
 TPT has contributed 500,000 biotic interaction records to GloBI, which will organize, standardize and integrate our records into existing species interaction datasets accessible via web tools and machines. Here, we provide examples of various parasite specimens with label data, demonstrate how biotic association data will be captured in different platforms, and provide a standard glossary of association terms. Over the course of the project, TPT and GloBI will continue to work with data providers to discover biotic interactions in their collections and refine standards specific to their data sharing workflows.
description: The creation of this poster and associated digital artifacts was made possible by the National Science Foundation award "Collaborative Research: Digitization TCN: Digitizing collections to trace parasite-host associations and predict the spread of vector-borne disease," Award numbers DBI:1901932 and DBI:1901926.
Accurate estimation of angular power spectra for maps with correlated masks
Creators: name: Surrao, Kristen M.
name: Philcox, Oliver H. E.
name: Hill, J. Colin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The widely used MASTER approach for angular power spectrum estimation was developed as a fast $C_{\ell}$ estimator on limited regions of the sky. This method expresses the power spectrum of a masked map ("pseudo-$C_\ell$") in terms of the power spectrum of the unmasked map (the true $C_\ell$) and that of the mask or weight map. However, it is often the case that the map and mask are correlated in some way, such as point source masks used in cosmic microwave background (CMB) analyses, which have nonzero correlation with CMB secondary anisotropy fields and other mm-wave sky signals. In such situations, the MASTER approach gives biased results, as it assumes that the unmasked map and mask have zero correlation. While such effects have been discussed before with regard to specific physical models, here we derive a completely general formalism for any case where the map and mask are correlated. We show that our result ("reMASTERed") reconstructs ensemble-averaged pseudo-$C_\ell$ to effectively exact precision, with significant improvements over traditional estimators for cases where the map and mask are correlated. In particular, we obtain an improvement in the mean absolute percent error from 30% with the MASTER result to essentially no error with the reMASTERed result for an integrated Sachs-Wolfe (ISW) field map with a mask built from the thresholded ISW field, and 10% to effectively zero for a Compton-$y$ map combined with an infrared source mask (the latter being directly relevant to actual data analysis). An important consequence of our result is that for maps with correlated masks it is no longer possible to invert a simple equation to obtain the true $C_\ell$ from the pseudo-$C_\ell$. Instead, our result necessitates the use of forward modeling from theory space into the observable domain of the pseudo-$C_\ell$. Our code is publicly available at https://github.com/kmsurrao/reMASTERed.
description: 14+9 pages, 6+6 figures; matches the version accepted for publication in PRD (https://journals.aps.org/prd/abstract/10.1103/PhysRevD.107.083521); code available at at https://github.com/kmsurrao/reMASTERed
Dynamics of intermediate mass black holes in globular clusters. Wander radius and anisotropy profiles
Creators: name: Di Cintio, Pierfrancesco
name: Pasquato, Mario
name: Barbieri, Luca
name: Trani, Alessandro A.
name: Di Carlo, Ugo N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We recently introduced a new method for simulating collisional gravitational N-body systems with approximately linear time scaling with $N$, based on the Multi-Particle Collision (MPC) scheme, previously applied in Plasma Physics. We simulate globular clusters with a realistic number of stellar particles (at least up to several times $10^6$) on a standard workstation. We simulate clusters hosting an intermediate mass black hole (IMBH), probing a broad range of BH-cluster and BH-average-star mass ratios, unrestricted by the computational constraints affecting direct N-body codes. We use either single mass models or models with a Salpeter mass function, with the IMBH initially sitting at the centre. The force exerted by and on the IMBH is evaluated with a direct scheme. We measure the evolution of the Lagrangian radii and core density and velocity dispersion over time. In addition, we study the evolution of the velocity anisotropy profiles. We find that models with an IMBH undergo core collapse at earlier times, the larger the IMBH mass the shallower, with an approximately constant central density at core collapse. The presence of an IMBH tends to lower the central velocity dispersion. These results hold independently of the mass function. For the models with Salpeter MF we observe that equipartition of kinetic energies is never achieved. Orbital anisotropy at large radii appears driven by energetic escapers on radial orbits. We measure the wander radius. Among the results we obtained, which mostly confirm or extend previously known trends that had been established over the range of parameters accessible to direct N-body simulations, we underline that the leptokurtic nature of the IMBH wander radius distribution might lead to IMBHs presenting as off-center more frequently than expected, with implications on observational IMBH detection.
description: 11 pages, 10 figures. Matching the version of the ms accepted in A&A
Gintropic Scaling of Scientometric Indexes
Creators: name: Biró, Tamás
name: Telcs, András
name: Józsa, Mété
name: Néda, Zoltán
Publisher: name: arXiv
Year: 2023
Subjects: subject: Digital Libraries (cs.DL)
subject: Computational Physics (physics.comp-ph)
subject: Popular Physics (physics.pop-ph)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: The most frequently used indicators for the productivity and impact of scientists are the total number of publication ($N_{pub}$), total number of citations ($N_{cit}$) and the Hirsch (h) index. Since the seminal paper of Hirsch, in 2005, it is largely debated whether the h index can be considered as an indicator independent of $N_{pub}$ and $N_{cit}$. Exploiting the Paretian form for the distribution of citations for the papers authored by a researcher, here we discuss scaling relations between h, $N_{pub}$ and $N_{cit}$. The analysis incorporates the Gini index as an inequality measure of citation distributions and a recently proposed inequality kernel, gintropy (resembling to the entropy kernel). We find a new upper bound for the h value as a function of the total number of citations, confimed on massive data collected from Google Scholar. Our analyses reveals also that the individualized Gini index calculated for the citations received by the publications of an author peaks around 0.8, a value much higher than the one characteristic for the usual socio-economic inequalities.
description: 12 pages, 6 Figures, Latex
Large $D$ gravity and low $D$ string via $α^{\prime}$ corrections
Creators: name: Ying, Shuxuan
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we generalize the correspondence between large $D$ gravity and low $D$ string theory to the most general case, including its T-dual solutions. It is well-known that the large $D$ limit of the Schwarzschild-Tangherlini black hole in gravity becomes a two-dimensional near-horizon geometry. Similarly, the large $D$ limit of its T-dual solution, obtained by the Buscher rules, namely the string black hole with a naked singularity, reduces to a two-dimensional near-singularity geometry. Both of these geometries are described by the two-dimensional low-energy effective action of string theory and are related to each other by scale-factor duality. Secondly, we demonstrate that these near-horizon/singuglarity geometries, including complete $α^{\prime}$ corrections, can be described by the two-dimensional Hohm-Zwiebach action. This approach allows for the derivation of non-perturbative and non-singular solutions. Furthermore, the Hohm-Zwiebach action provides a systematic way to investigate the $α^{\prime}$-corrected near-horizon/singularity geometries of different kinds of black holes, which are difficult to achieve through the Wess-Zumino-Witten (WZW) model method.
description: v2: 27 pages, 3 figures, references added, version to appear in JHEP
Discovery of the luminous X-ray ignition eRASSt J234402.9$-$352640; I. Tidal disruption event or a rapid increase in accretion in an active galactic nucleus?
Creators: name: Homan, D.
name: Krumpe, M.
name: Markowitz, A.
name: Saha, T.
name: Gokus, A.
name: Partington, E.
name: Lamer, G.
name: Malyali, A.
name: Liu, Z.
name: Rau, A.
name: Grotova, I.
name: Cackett, E. M.
name: Buckley, D. A. H.
name: Ciroi, S.
name: Di Mille, F.
name: Gendreau, K.
name: Gromadzki, M.
name: Krishnan, S.
name: Schramm, M.
name: Steiner, J. F.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: In November 2020, a new, bright object, eRASSt J234402.9$-$352640, was discovered in the second all-sky survey of SRG/eROSITA. The object brightened by a factor of at least 150 in 0.2--2.0 keV flux compared to an upper limit found six months previous, reaching an observed peak of $1.76_{-0.24}^{+0.03} \times 10^{-11}$ erg cm$^{-2}$ s$^{-1}$. The X-ray ignition is associated with a galaxy at $z=0.10$, making the peak luminosity log$_{10}(L_{\rm 0.2-2keV}/[\textrm{erg s}^{-1}])$=$44.7\pm0.1$. Around the time of the rise in X-ray flux, the nucleus of the galaxy brightened by approximately 3 mag. in optical photometry, after correcting for the host. We present data from Swift, XMM-Newton, and NICER, which reveal a very soft spectrum as well as strong 0.2--2.0 keV flux variability on multiple timescales. Optical spectra taken in the weeks after the ignition event show a blue continuum with broad, asymmetric Balmer emission lines, and high-ionisation ([OIII]$λλ$4959,5007) and low-ionisation ([NII]$λ$6585, [SII]$λλ$6716,6731) narrow emission lines. Following the peak in the optical light curve, the X-ray, UV, and optical photometry all show a rapid decline. The X-ray light curve shows a decrease in luminosity of $\sim$0.45 over 33 days and the UV shows a drop of $\sim$0.35. eRASSt J234402.9$-$352640 also shows a brightening in the mid-infrared, likely powered by a dust echo of the luminous ignition. We find no evidence in Fermi-LAT $γ$-ray data for jet-like emission. The event displays characteristics of a tidal disruption event (TDE) as well as of an active galactic nucleus (AGN), complicating its classification. Based on the softness of the X-ray spectrum, the presence of high-ionisation optical emission lines, and the likely infrared echo, we find that a TDE within a turned-off AGN best matches our observations.
description: 25 pages, 17 figures, 9 tables, Accepted for publication in A&A
Bruce-Vincent transference numbers from molecular dynamics simulations
Creators: name: Shao, Yunqi
name: Zhang, Chao
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Transference number is a key design parameter for electrolyte materials used in electrochemical energy storage systems. However, the determination of the true transference number from experiments is rather demanding. On the other hand, the Bruce-Vincent method is widely used in the lab to measure transference numbers of polymer electrolytes approximately, which becomes exact in the limit of infinite dilution. Therefore, theoretical formulations to treat the Bruce-Vincent transference number and the true transference number on an equal footing are clearly needed. Here we show how the Bruce-Vincent transference number for concentrated electrolyte solutions can be derived in terms of the Onsager coefficients, without involving any extrathermodynamic assumptions. By demonstrating it for the case of PEO-LiTFSI system, this work opens the door to calibrating molecular dynamics (MD) simulations via reproducing the Bruce-Vincent transference number and using MD simulations as a predictive tool for determining the true transference number.
Central exclusive diffractive production of a single photon in high-energy proton-proton collisions within the tensor-Pomeron approach
Creators: name: Lebiedowicz, Piotr
name: Nachtmann, Otto
name: Szczurek, Antoni
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We discuss central-exclusive production (CEP) of photons via different fusion processes in the reaction $pp \to pp γ$ at high energies, available at RHIC and LHC, within the tensor-pomeron model. We consider two types of processes, the photoproduction contribution via the photon-pomeron and photon-reggeon fusion reactions, and the purely diffractive contribution via the reggeon-pomeron and odderon-pomeron fusion reactions. We present predictions for the measurements of photons at midrapidity, $|{\rm y}| < 2.5$, and at relatively low transverse momentum, $0.1~{\rm GeV} < k_{\perp} < 1~{\rm GeV}$. To check the main results of our study the measurement of the outgoing protons is not necessary. This is of relevance, e.g., for the present version of the ALICE detector at the LHC. Several differential distributions, for instance, in ${\rm y}$, $k_{\perp}$ and $ω$, the rapidity, the absolute value of the transverse momentum, and the energy of the photon, respectively, are presented. We show that the photoproduction is an important process in the kinematic region specified above. There it gives a much larger cross section than diffractive bremsstrahlung. This is remarkable as the CEP cross section is of order $α_{\rm em}^{3}$ whereas the bremsstrahlung one is only of order $α_{\rm em}$. On the other hand, the soft-photon bremsstrahlung where the basic $pp \to pp$ reaction is due to strong interaction diffraction is more important than CEP in the forward rapidity range, $|{\rm y}| > 4$, and/or at very low $k_{\perp}$. We leave it as a challenge for the planned ALICE 3 experiment at the LHC to study these two contributions to soft photon production in $pp$ collisions. This could shed new light on the so called ``soft photon puzzle'' in hadron-hadron collisions.
description: 27 pages, 13 figures
Magnifying absolute instruments for optically homogeneous regions
Creators: name: Tyc, Tomas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We propose a class of magnifying absolute optical instruments with a positive isotropic refractive index. They create magnified stigmatic images, either virtual or real, of optically homogeneous three-dimensional spatial regions within geometrical optics.
description: 4 pages, 8 figures
Search through time is like search through space : behavioural and electrophysiological evidence
Creators: name: Blundon, Elizabeth Gwynne
Publisher: name: University of British Columbia
Year: 2015

description: We conducted four experiments comprised of sequential auditory and visual searches in order to further explore the generalizability of the search asymmetry phenomenon to different sensory modalities, and to the sequential presentation of items in search arrays. It has been shown that search time to identify targets that contain features that distractors don’t have (feature-present targets) is faster than search time to identify targets that are missing features that distractors have (feature-absent targets). In Experiment 1 participants listened to auditory oddball sequences, consisting of two types of five-tone runs: the flat run, which consisted of five pure tones of the same frequency (the feature-absent target), and the change run, which consisted of four pure tones of the same frequency, followed by a fifth tone of a different frequency (the feature-present target). In some sequences the change runs were common and the flat runs were rare (the feature-present condition), while in other sequences these roles were reversed (the feature-absent condition). Experiments 2, 3 and 4 used the same protocol, however the visual stimuli consisted of rings (annuli) that differed by some feature (colour in Experiment 2, contrast in Experiment 3, and shade in Experiment 4). In all four experiments participant reaction times (RT) and electrophysiological (P300) responses to rare target patterns were recorded. In Experiments 1, 2 and 3, the reaction time and P300 latencies to identify feature-present targets were significantly faster than those to feature-absent targets, suggesting strong similarities between simultaneous visual search, and sequential auditory and visual search. What’s more, P300 responses to feature-present targets exhibited strong characteristics of both P3a and P3b subcomponents, while feature-absent responses only resembled that of the P3b. By contrast, the results of the fourth experiment were inconclusive. In Experiment 4 the saliency of the feature difference in the change runs was significantly reduced compared to that of the first three experiments, yielding longer reaction times and weaker P300 responses. Implications for the current understanding of search strategies associated with easy (feature-present) and difficult (feature-absent) searches, as well as the locus of the search asymmetry phenomenon, are discussed.
Qubit Entanglement Dephasing Dynamics Driven by a Bath of Spins
Creators: name: Xu, Jie
name: Jing, Jun
name: Yu, Ting
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the entanglement dynamics for a two-spin system coupled to a spin environment of different configurations by z-x type interaction. The models considered in this paper are solved both analytically and numerically giving rise to some concise analytical expressions when certain approximations are properly made. Our purpose is to find how the initial states of the environment with different numbers of spins affect the decay or revival of the entanglement between central qubits. In Particular, it is found that the block-entangled environment could speed up the decay and revival of the qubit entanglement. Our results exhibit some interesting features that have not been found for a boson bath.
description: 13 pages, 8 figures.Submitted to New Journal of Physics
Asymptotic cone of semisimple orbits for symmetric pairs
Creators: name: Nishiyama, Kyo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14M15, 14E15

description: Let G be a reductive algebraic group over the complex field and O_h be a closed adjoint orbit through a semisimple element h. By a result of Borho and Kraft (1979), it is known that the asymptotic cone of the orbit O_h is the closure of a Richardson nilpotent orbit corresponding to a parabolic subgroup whose Levi component is the centralizer Z_G(h) in G. In this paper, we prove an analogue on a semisimple orbit for a symmetric pair (G, K).
description: 14 pages
Dual-mode adaptive-SVD ghost imaging
Creators: name: Wang, Dajing
name: Liu, Baolei
name: Song, Jiaqi
name: Wang, Yao
name: Shan, Xuchen
name: Wang, Fan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Optics (physics.optics)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Physical sciences

description: In this paper, we present a dual-mode adaptive singular value decomposition ghost imaging (A-SVD GI), which can be easily switched between the modes of imaging and edge detection. It can adaptively localize the foreground pixels via a threshold selection method. Then only the foreground region is illuminated by the singular value decomposition (SVD) - based patterns, consequently retrieving high-quality images with fewer sampling ratios. By changing the selecting range of foreground pixels, the A-SVD GI can be switched to the mode of edge detection to directly reveal the edge of objects, without needing the original image. We investigate the performance of these two modes through both numerical simulations and experiments. We also develop a single-round scheme to halve measurement numbers in experiments, instead of separately illuminating positive and negative patterns in traditional methods. The binarized SVD patterns, generated by the spatial dithering method, are modulated by a digital micromirror device (DMD) to speed up the data acquisition. This dual-mode A-SVD GI can be applied in various applications, such as remote sensing or target recognition, and could be further extended for multi-modality functional imaging/detection.
Three-dimensional dynamics of strongly twisted magnetar magnetospheres: Kinking flux tubes and global eruptions
Creators: name: Mahlmann, J. F.
name: Philippov, A. A.
name: Mewes, V.
name: Ripperda, B.
name: Most, E. R.
name: Sironi, L.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The origins of the various outbursts of hard X-rays from magnetars (highly magnetized neutron stars) are still unknown. We identify instabilities in relativistic magnetospheres that can explain a range of X-ray flare luminosities. Crustal surface motions can twist the magnetar magnetosphere by shifting the frozen-in footpoints of magnetic field lines in current-carrying flux bundles. Axisymmetric (2D) magnetospheres exhibit strong eruptive dynamics, as to say, catastrophic lateral instabilities triggered by a critical footpoint displacement of $ψ_{\rm crit}\gtrsimπ$. In contrast, our new three-dimensional (3D) twist models with finite surface extension capture important non-axisymmetric dynamics of twisted force-free flux bundles in dipolar magnetospheres. Besides the well-established global eruption resulting (as in 2D) from lateral instabilities, such 3D structures can develop helical, kink-like dynamics, and dissipate energy locally (confined eruptions). Up to $25\%$ of the induced twist energy is dissipated and available to power X-ray flares in powerful global eruptions, with most of our models showing an energy release in the range of the most common X-ray outbursts, $\lesssim 10^{43}$erg. Such events occur when significant energy builds up deeply buried in the dipole magnetosphere. Less energetic outbursts likely precede powerful flares, due to intermittent instabilities and confined eruptions of a continuously twisting flux tube. Upon reaching a critical state, global eruptions produce the necessary Poynting-flux-dominated outflows required by models prescribing the fast radio burst production in the magnetar wind -- for example, via relativistic magnetic reconnection or shocks.
description: 21 pages, 11 figures, Accepted for publication by ApJL
Rejoinder
Creators: name: Kass, Robert E.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Rejoinder of "Statistical Inference: The Big Picture" by R. E. Kass [arXiv:1106.2895]
description: Published in at http://dx.doi.org/10.1214/11-STS337REJ the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Reparameterization of special contours for boundary value problems in queueing systems
Creators: name: Epema, Cody
Publisher: name: University of British Columbia
Year: 2015

description: We present several tests to detect whether a simple reparameterization of the contour is possible for the Riemann-Hilbert Boundary Value Problem associated with the stationary distribution of a two dimensional queueing system. We cover several special cases, some of which have been previously covered using different methods, and present an expansion on the existing theory to the case of elliptical contours. Two fast heuristic tests are also presented. Additionally, we construct a formal BVP solution for queueing systems with homogeneous fundamental equations.
Regenerative Post COVID-19 Recovery Measures: The Case of Rwanda
Creators: name: Ben Abdallah, Alaa
name: Ackerman, Rudi Michiel
Publisher: name: European Journal of Social Impact and Circular Economy
Year: 2020

description: Governments worldwide are scrambling to combat both the biological and economic effects of the global COVID-19 pandemic. By using Rwanda as a case study, this paper analyzes two of the existent home-grown poverty alleviation initiatives for food security: Girinka (Have a cow) and Akarima k’igikoni (Kitchen Gardens). Using descriptive statistical data gathered during the pandemic in Rwanda’s capital, Kigali, we found rainwater collection practices already well established. We find that many households already separate waste, but that only some households in the peri-urban areas we investigated practice composting and home-gardening. We conclude with several recommendations on how the Rwandan government’s commitment to sustainable development and urban agglomeration in the Vision 2050 strategy can be achieved. Using already well-established policy mechanisms like the “Umudugudu” (=Village) network and the Akarima k’igikoni initiative, Rwanda can better weather the economic effects of the global pandemic. These mechanisms present a valuable opportunity for Rwandan businesses to invest in composting activities and regenerative practices in their buildings and waste management systems. Other developing countries can also learn valuable lessons from an environmentally sustainable and home-grown poverty alleviation policy.
description: European Journal of Social Impact and Circular Economy, Vol 1 No 3 (2020): CSR and Circular Economy as a remedy for companies fighting systemic crises
Retrieval study of cool, directly imaged exoplanet 51 Eri b
Creators: name: Whiteford, Niall
name: Glasse, Alistair
name: Chubb, Katy L.
name: Kitzmann, Daniel
name: Ray, Shrishmoy
name: Phillips, Mark W.
name: Biller, Beth A.
name: Palmer, Paul I.
name: Rice, Ken
name: Waldmann, Ingo P.
name: Changeat, Quentin
name: Skaf, Nour
name: Wang, Jason
name: Edwards, Billy
name: Al-Refaie, Ahmed
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Retrieval methods are a powerful analysis technique for modelling exoplanetary atmospheres by estimating the bulk physical and chemical properties that combine in a forward model to best-fit an observed spectrum, and they are increasingly being applied to observations of directly-imaged exoplanets. We have adapted TauREx3, the Bayesian retrieval suite, for the analysis of near-infrared spectrophotometry from directly-imaged gas giant exoplanets and brown dwarfs. We demonstrate TauREx3's applicability to sub-stellar atmospheres by presenting results for brown dwarf benchmark GJ 570D which are consistent with previous retrieval studies, whilst also exhibiting systematic biases associated with the presence of alkali lines. We also present results for the cool exoplanet 51 Eri b, the first application of a free chemistry retrieval analysis to this object, using spectroscopic observations from GPI and SPHERE. While our retrieval analysis is able to explain spectroscopic and photometric observations without employing cloud extinction, we conclude this may be a result of employing a flexible temperature-pressure profile which is able to mimic the presence of clouds. We present Bayesian evidence for an ammonia detection with a 2.7$σ$ confidence, the first indication of ammonia in an exoplanetary atmosphere. This is consistent with this molecule being present in brown dwarfs of a similar spectral type. We demonstrate the chemical similarities between 51 Eri b and GJ 570D in relation to their retrieved molecular abundances. Finally, we show that overall retrieval conclusions for 51 Eri b can vary when employing different spectral data and modelling components, such as temperature-pressure and cloud structures.
Community structure and availability of edible primary producers to herbivores along a temperature gradient
Creators: name: Caulk, Natalie Catherine
Publisher: name: University of British Columbia
Year: 2015

description: Warming can influence the rate of plant-herbivore interactions through direct effects on individual metabolism, resource use, and growth rates, and via indirect effects on the properties of plant resources and behavior of consumers. Through these processes, temperature can affect the structure and function of food webs, though whether these overall responses reflect primarily direct or indirect effects of temperature is unclear. To begin to address this problem, I quantified the effects of temperature and grazing on primary producer traits and relative abundance to understand how temperature directly and indirectly affects an important aspect of food webs: resource availability to herbivores. I hypothesized that warming would decrease the availability of edible resources to consumers through decreased abundance, body size and shifts among dominant functional groups, and that these effects would be strengthened in the presence of consumers. I tested this hypothesis in freshwater algal-grazer communities maintained across an 11°C temperature gradient over 11 weeks. I observed direct, positive effects of temperature on whole-system oxygen fluxes (i.e. through net primary productivity and ecosystem respiration), and direct negative effects on phytoplankton abundance and body size, with higher relative abundance of small phytoplankton. Herbivores drove shifts in phytoplankton size distributions across the temperature gradient through size-selective consumption of large phytoplankton. Warming shifted species composition among algae from plankton-dominated to periphyton-dominated assemblages, consistent with indirect effects of warming on competitive interactions. Taken together, shifts in abundance, body size and functional group dominance over the temperature gradient decreased the availability of preferred plant resources to filter-feeding zooplankton at warmer temperatures, which may alter food web structure and function, especially under increased grazing pressure. I conclude that resource-availability shifts are predictable with warming, and that temperature-dependent community theory can be expanded to include these indirect effects of temperature on species interactions.
The potential of circular businesses in the post-COVID era: a system dynamics view
Creators: name: Costanza, Francesca
Publisher: name: European Journal of Social Impact and Circular Economy
Year: 2020

description: The last decade has witnessed the flourishing interest of scholars and policymakers to the application of Circular Economy (CE) principles, which has been pointed out as a compelling goal for business and society at current times of Coronavirus pandemic. This paper aims to describe the roles of companies and consumers in CE implementation, the basic mechanisms of circular business creation and diffusion, and their potential contribution to the recovery post-COVID. For the purpose, it has been adopted a system dynamics (SD) view to build an insight model integrating selected literature inputs. Distinguishing between “born circular” and “converted circular” businesses, model dynamics highlight the interplay of circular businesses and responsible consumers, postulating key feedbacks able to affect, respectively, the conversion of companies and people to virtuous productive and consumption behaviours. Finally, the consolidation of such mechanisms contributes to the alleviation of specific socioeconomic and environmental issues ascribable to the Coronavirus spreading.
description: European Journal of Social Impact and Circular Economy, Vol 1 No 3 (2020): CSR and Circular Economy as a remedy for companies fighting systemic crises
High-fidelity reaction kinetic modeling of hot-Jupiter atmospheres incorporating thermal and UV photochemistry enhanced by metastable CO(a3Pi)
Creators: name: Yang, Jeehyun
name: Gudipati, Murthy S.
name: Henderson, Bryana L
name: Fleury, Benjamin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: A detailed modeling of simultaneous UV-photochemical and thermochemical processes in exoplanet atmosphere-like conditions is essential for the analysis and interpretation of a vast amount of current and future spectral data from exoplanets. However, a detailed reaction kinetic model that incorporates both UV photochemistry and thermal chemistry is challenging due to the massive size of the chemical system as well as to the lack of understanding of photochemistry compared to thermal-only chemistry. Here, we utilize an automatic chemical reaction mechanism generator to build a high-fidelity thermochemical reaction kinetic model later then incorporated with UV-photochemistry enhanced by metastable triplet-state carbon monoxide (a3Pi). Our model results show that two different photochemical reactions driven by Lyman-a photons (i.e. H2 + CO(a3Pi) -> H + HCO and CO(X1Sig+) + CO(a3Pi) -> C(3P) + CO2) can enhance thermal chemistry resulting in significant increases in the formation of CH4, H2O, and CO2 in H2-dominated systems with trace amounts of CO, which qualitatively matches with the observations from previous experimental studies. Our model also suggests that at temperatures above 2000 K, thermal chemistry becomes the dominant process. Finally, the chemistry simulated up to 2500 K does not produce any larger species such as C3 species, benzene or larger (i.e. PAHs). This might indicate that the photochemistry of C2 species such as C2H2 might play a key role in the formation of organic aerosols observed in the previous experimental study.
description: 58 pages, 17 figures, 4 tables, Manuscript accepted for publication in Astrophysical Journal