cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Δοκιμασίες ανίχνευσης β-λακταμασών στα Gram (-) βακτήρια
Creators: name: Παύλου, Μαρία Χρήστου
Publisher: name: Aristotle University of Thessaloniki
Year: 2025
Subjects: β-λακταμάσες
Δοκιμασίες ανίχνευσης
Φαινοτυπικές και Μοριακές μέθοδοι
b-lactamases
Detection tests
Phenotypic and Molecular methods

description: Σκοπός της διατριβής ήταν η μελέτη των δοκιμασιών ανίχνευσης των β-λακταμασών στα Gram (-) βακτήρια. Αναφερθήκαμε στην μικροβιακή αντοχή και στους μηχανισμούς που ενεργοποιούν τα βακτήρια προκειμένου να αποκτήσουν αντοχή έναντι των αντιμικροβιακών ουσιών. Αναφερθήκαμε ακόμα στα αντιβιοτικά και συγκεκριμένα στα β-λακταμικά και περιγράψαμε τους μηχανισμούς δράσης τους. Στη συνέχεια περιγράψαμε την ταξινόμηση των β-λακταμασών και αναλύσαμε τις κυριότερες β-λακταμάσες. Παρουσιάσαμε τις φαινοτυπικές και μοριακές μεθόδους που χρησιμοποιούνται για την ανίχνευση των β-λακταμασών και συγκεκριμένα των ESBL και των καρβαπενεμασών. Περιγράψαμε αναλυτικά τις μεθόδους, τα ένζυμα που ανιχνεύει η κάθε μέθοδος καθώς και τους περιορισμούς ανίχνευσης της κάθε μεθόδου. Συγκρίναμε τις μεθόδους με βάση τα ένζυμα που ανιχνεύουν,το κόστος και τον απαιτούμενο χρόνο.
description: The aim of the present thesis was to study the detection assays for b-lactamases in Gram (-) bacteria. We discussed antimicrobial resistance and the mechanisms that bacteria activate to acquire resistance to antimicrobials. We also discussed antibiotics and particularly b-lactams and we described their mechanisms of action. We then described the classification of b-lactamases and analysed the main b-lactamases. We presented the phenotypic and molecular methods used for the detection of b-lactamases, in particular ESBL and carbapenemases. We described in detail the methods, the enzymes detected by each method and the detection limitations of each method. We compared the methods based on the enzymes they detect, the cost and the required time.
The study of the chemical characterization of gastric inhibitory polypeptide (GIP) and the role of GIP in the enteroinsular axis
Creators: name: Kwauk, Sam Tsung-Ming
Publisher: name: University of British Columbia
Year: 2010

description: The dual objectives of this thesis were to study the physiological role of GIP in the enteroinsular axis and to chemically characterize a side fraction identified in the purification of GIP. In the physiological studies, the dependency of the insulinotropic action of GIP on the prevailing state of glycaemia was confirmed in dogs using a system of steady state hyperglycaemia. GIP, from both exogenous and endogenous sources, was demonstrated to potentiate insulin release in the presence of moderate hyperglycaemia. Both glucose and fat administered enterally released immunoreactive-GIP (IR-GIP) and potentiated immunoreactive insulin (IRI) release during moderate hyperglycaemia (150 mg% above basal). Intravenous administration of GIP at 2.0 μg/kq.h was also capable of eliciting insulinotropic action during moderate hyperglycaemia. A mixture of ten amino acids was demonstrated to potentiate insulin release with mild hyperglycaemia (40 mg% above fasting) regardless of routes (intravenous, intraduodenal and oral) of administration. However, the release of IR-GIP was not demonstrated following the administration of the amino acid mixture. Arginine and alanine infused individually did not potentiate insulin release in the presence of mild hyperglycaemia. Intraduodenal hydrochloric acid infusion was also demonstrated not to release IR-GIP in the presence of mild hyperglycaemia. The interactions of GIP with tricarboxylic acid cycle intermediates and pyruvate were studied in euglycaemic conditions in dogs. Intravenous administration of individual metabolites (a-ketoglutaric acid, succinate and pyruvate) on an equimolar basis were shown not to be insulinotropic in the presence or the absence of concurrent GIP infusion (0.4 μg/kg.h). The presence of a minor peptide component in the stage III GIP was initially identified by thin layer chromatography. Confirmation of the presence of this minor component was obtained from polyacrylamide-urea gel. These techniques were unsuitable for preparative separation, as were conventional gel filtration and ion exchange separation. Further purification of GIP on high pressure liquid chromatography indicated the presence of a 5% minor peptide component which was eventually shown to contain two less amino acid residues (tyrosine and alanine) than GIP. The amino acid sequence of GIP III indicated the presence of a peptide component with an amino acid sequence different from GIP in that the first two amino acid residues of the N-terminal portion of the molecule (tyrosine and alanine) were missing. The lack of inhibitory activity to pentagastrin-stimulated acid secretion by synthetic GIP led to a reinvestigation of the amino, acid sequence of the molecule. The work in collaboration with Jornvall (Sweden) indicated an error, in that the original sequence included a second glutamine in position 30.
Nonlinear harmonic generation and devices in doubly-resonant Kerr cavities
Creators: name: Hashemi, Hila
name: Rodriguez, Alejandro W.
name: Joannopoulos, J. D.
name: Soljačić, Marin
name: Johnson, Steven G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We describea theoretical analysis of the nonlinear dynamics of third-harmonic generation ($ω\to3ω$) via Kerr ($\chithree$) nonlinearities in a resonant cavity with resonances at both $ω$ and $3ω$. Such a doubly resonant cavity greatly reduces the required power for efficient harmonic generation, by a factor of $\sim V/Q^2$ where $V$ is the modal volume and $Q$ is the lifetime, and can even exhibit 100% harmonic conversion efficiency at a critical input power. However, we show that it also exhibits a rich variety of nonlinear dynamics, such as multistable solutions and long-period limit cycles.We describe how to compensate for self/cross-phase modulation (which otherwise shifts the cavity frequencies out of resonance), and how to excite the different stable solutions (and especially the high-efficiency solutions) by specially modulated input pulses.
description: 12 pages, 12 figures
The formation of young B/PS bulges in edge-on barred galaxies
Creators: name: Wozniak, H.
name: Michel-Dansac, L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report about the fact that the stellar population that is born in the gas inflowing towards the central regions can be vertically unstable leading to a B/PS feature remarkably bluer that the surrounding bulge. Using new chemodynamical simulations we show that this young population does not remain as flat as the gaseous nuclear disc and buckles out of the plane to form a new boxy bulge. We show that such a young B/PS bulge can be detected in colour maps.
description: 2 pages, 5 figures, to appear in IAU Symposium 245, Formation and Evolution of Galaxy Bulges, M. Bureau, E. Athanassoula, and B. Barbuy (eds.), Oxford, 16-20 July 2007
Ultrafast photophysics and energy losses in emerging photovoltaic materials and devices
Creators: name: Hopper, Thomas Roy
Publisher: name: Imperial College London
Year: 2020

description: The mechanisms that govern the transformation and dissipation of energy in semiconductors must be understood to advance optoelectronic technologies to their fullest extent. This thesis aims to unravel the evolution and energy losses of electronically excited states in novel solution-processed materials for photovoltaics. This is achieved by implementing ultrafast laser spectroscopies devised to target efficiency-limiting processes in conditions relevant to device operation. Part of the research herein examines the deleterious relaxation of high-energy ("hot") charge carriers in metal-halide perovskites and their nanocrystal analogues using an all-optical "pump-push-probe" approach. The results show that carrier "cooling" in these materials is dictated by the lattice composition, and unlike other low-dimensional semiconductors, insensitive to the crystal size or surface properties. The multi-pulse methodology also reveals that hot carriers can lose their energy to cold carriers, which highlights a previously unaddressed competition between carrier-carrier and carrier-lattice interactions in these materials. The remainder of the thesis deals with charge separation at the interface between electron-donating and accepting organic semiconductors. Spectroscopies with optical, emission and photocurrent detection convey slower charge separation when the donor and acceptor are more closely aligned in energy. In spite of the slower dynamics and small "driving energy" of these systems, efficient long-range delocalisation of charges occurs in a manner that does not entail inexorable non-radiative recombination. Moreover, the electric field inside working solar cells is discovered to directly aid the preliminary step to this process, contrary to conventional wisdom. Both research strands of the thesis bring unique insight into the photophysics of "soft" semiconductors, and also establish frameworks for the design of high-performance solar cells based on molecular and/or nanoscale materials. These guidelines and the device-oriented approaches developed herein could be instrumental in unlocking the functionality of other up-and-coming materials systems for energy, photonic and nanoelectronic applications.
Higher mass limits of neutron stars from the equation of states in curved spacetime
Creators: name: Hossain, Golam Mortuza
name: Mandal, Susobhan
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In order to solve the Tolman-Oppenheimer-Volkoff equations for neutron stars, one routinely uses the equation of states which are computed in the Minkowski spacetime. Using a first-principle approach, it is shown that the equation of states which are computed within the curved spacetime of the neutron stars include the effect of gravitational time dilation. It arises due to the radially varying interior metric over the length scale of the star and consequently it leads to a much higher mass limit. As an example, for a given set of parameters in a $σ-ω$ model of nuclear matter, the maximum mass limit is shown to increase from $1.61 M_{\odot}$ to $2.24 M_{\odot}$ due to the inclusion of gravitational time dilation.
description: v1 10 pages, 10 figures; v2 11 pages, matches with published version
Additional file 1 of The mtDNA mutation spectrum in the PolG mutator mouse reveals germline and somatic selection
Creators: name: Maclaine, Kendra D.
name: Stebbings, Kevin A.
name: Llano, Daniel A.
name: Havird, Justin C.
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 1: Supplementary Tables 1, 2.
Universal relation for supernova gravitational waves
Creators: name: Sotani, Hajime
name: Takiwaki, Tomoya
name: Togashi, Hajime
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Using the numerical simulation data for two-dimensional core-collapse supernova, we examine the protoneutron star (PNS) asteroseismology with the relativistic Cowling approximation. As shown in the previous study, the gravitational wave signals appearing in the numerical simulation can be well identified with the gravity (fundamental) oscillation in the early (later) phase before (after) the avoided crossing between the gravity and fundamental oscillations. On the other hand, the time evolution of supernova gravitational waves strongly depends on the PNS models, such as the progenitor mass and the equation of state for dense matter. Nevertheless, we find that the fundamental and gravity mode frequencies according to the gravitational wave signals appearing in the numerical simulations can be expressed as a function of the protoneutron star average density independently of the PNS models. Using the average density, we derive the empirical formula for supernova gravitational wave frequency. In addition, we confirm that the dependence of the PNS surface density on the PNS average density is almost independent of the PNS models and also discuss how the different treatment of the non-uniform matter in the equation of state affects the observables.
description: accepted for publication in PRD; For the waveform data of gravitational waves, see https://doi.org/10.5281/zenodo.5555497
Factors Affecting Appropriate Reliance on Artificial Intelligence Decision Support Systems
Creators: name: Dunning, Richard
Publisher: name: Carnegie Mellon University
Year: 2024
Subjects: subject: Artificial Intelligence and Image Processing
subject: FOS: Computer and information sciences

description: Many applications of AI require humans and AI advisors to make decisions  collaboratively; however, success depends on how appropriately humans rely on the AI agent.  We demonstrated an evaluation method for a platform that used neural network agents of varying  skill levels for the simple strategic game of Connect Four. We manipulated the presence,  sequence, skill, and information display of Artificial Intelligence (AI) advice in a strategy game  against another AI opponent that sometimes varied its skill to measure their effect on users’  performance.
Human agent teams outperformed unaided subjects with those receiving the AI  recommendations simultaneously achieving the best results. Although team performance was  higher and subjects improved during game play, there was little evidence of learning from their  AI advisors. AI reliability proved to be the greatest determiner of team performance with  subjects retaining trust in higher skilled advisors even in varied environments. Those with higher  numeracy demonstrated the highest ability to make use of AI advice including more detailed  output formats including ranking of choices and probabilities. More reliable AI agents correlated  to higher AI trust while higher self-confidence correlated to greater rejection of AI advice,  greater confidence in success, but slightly lower performance. 
The value of these human agent teams depended on AI reliability, users’ ability to extract  lessons from their advice, and users’ trust in that advice. Organizations implementing human  agent teams should conduct testing to know how well users appropriately rely on AI  recommendations.
Cephennium atomarium SAULCY 1870
Creators: name: Assing, Volker
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Cephennium
Cephennium atomarium

description: Cephennium atomarium SAULCY, 1870 (Map 2)
Material examined: SPAIN: 1♂, Navarra, Pamplona, Orbaitzeta env., 4.VIII.1971 (cAss).
Material from Spain examined by C. Besuchet (unpubl.): SPAIN: Cantabria: 17♂♂, 9♀♀, Santander, Ruente, Monte Aa, leg. Franz (MHNG, NHMW); 2♂♂, Santander, W Beranga, Jesus de Montes, leg. Franz (NHMW); 5♂♂, 6♀♀, Santander, Santoña, leg. Besuchet (MHNG); 34 exs., Santander, Ramales-Ranestosa, leg. Besuchet (MHNG); 13 exs., Santander, Lliendo env., Mte. de Candina, leg. Besuchet (MHNG); 1♂, San Sebastian, Rio de Deva [Dera?], leg. Besuchet (MHNG). Castilla y León: 2♂♂, Burgos, Puerto de Carrales, leg. Franz (MHNG, NHMW). País Vasco: 1♂, Tolosa env., Mte. Alzo, leg. Franz (NHMW).
This anophthalmous species is remarkably widespread in the French Pyrenees and in North Spain, where it has been recorded from Cantabria across País Vasco and Castilla y León to Navarra (FRANZ 1963, OROUSSET 2018; Besuchet unpubl.) (Map 2). For illustrations of the male sexual characters and numerous records, including two from Navarra, see OROUSSET (2018).
description: Published as part of Assing, Volker, 2021, On the Cephennium fauna of the Iberian Peninsula and the Atlantic Islands (Coleoptera, Staphylinidae, Scydmaeninae), pp. 891-931 in Linzer biologische Beiträge 52 (2) on page 918, DOI: 10.5281/zenodo.5039032
Level-rank duality of untwisted and twisted D-branes of the so(N)_K WZW model
Creators: name: Naculich, Stephen G.
name: Ripman, Benjamin H.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyze the level-rank duality of untwisted and epsilon-twisted D-branes of the so(N)_K WZW model. Untwisted D-branes of so(N)_K are characterized by integrable tensor and spinor representations of so(N)_K. Level-rank duality maps untwisted so(N)_K D-branes corresponding to (equivalence classes of) tensor representations onto those of so(K)_N. The epsilon-twisted D-branes of so(2n)_2k are characterized by (a subset of) integrable tensor and spinor representations of so(2n-1)_2k+1. Level-rank duality maps spinor epsilon-twisted so(2n)_2k D-branes onto those of so(2k)_2n. For both untwisted and epsilon-twisted D-branes, we prove that the spectrum of an open string ending on these D-branes is isomorphic to the spectrum of an open string ending on the level-rank-dual D-branes.
description: 18 pages
Misconduct and plagiarism related to the grant proposal
Creators: name: Jia, Lin
Publisher: name: Zenodo
Year: 2023

description: This scenario presents misconduct and plagiarism related to the grant proposal.

Supervisor B asked the PhD candidate A to draft a grant proposal for him. When A wrote the grant proposal, she plagiarized many contents of the "case samples" provided by the tutoring agency. After this grant proposal was submitted in the name of supervisor B, it was reviewed by the fund agency and determined to be plagiarism.

The original authors C, D, E and F, worked together as a research team, shared a similar literature review and methodology. They were involved in plagiarism from each other.

It focuses on misconduct and plagiarism regarding:

Involve in plagiarism

Submit the same or similar grant proposal three times

Data management security

Asking someone else to write for he/she is misconduct.

Sell someone’s disapproved grant proposal for profits
Measurement of Charge and Light Yields for $^{127}$Xe L-Shell Electron Captures in Liquid Xenon
Creators: name: Temples, Dylan J
name: McLaughlin, Jacob
name: Bargemann, Jack
name: Baxter, Daniel
name: Cottle, Amy
name: Dahl, C Eric
name: Lippincott, W Hugh
name: Monte, Alissa
name: Phelan, Jason
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Dark matter searches using dual-phase xenon time-projection chambers (LXe-TPCs) rely on their ability to reject background electron recoils (ERs) while searching for signal-like nuclear recoils (NRs). ER response is typically calibrated using $β$-decay sources, such as tritium, but these calibrations do not characterize events accompanied by an atomic vacancy, as in solar neutrino scatters off inner shell electrons. Such events lead to emission of X-rays and Auger electrons, resulting in higher electron-ion recombination and thus a more NR-like response than inferred from $β$-decay calibration. We present a cross-calibration of tritium $β$-decays and $^{127}$Xe electron-capture decays (which produce inner-shell vacancies) in a small-scale LXe-TPC and give the most precise measurements to date of light and charge yields for the $^{127}$Xe L-shell electron-capture in liquid xenon. We observe a 6.9$σ$ (9.2$σ$) discrepancy in the L-shell capture response relative to tritium $β$-decays, measured at a drift field of 363 $\pm$ 14 V/cm (258 $\pm$ 13 V/cm), when compared to simulations tuned to reproduce the correct $β$-decay response. In dark matter searches, use of a background model that neglects this effect leads to overcoverage (higher limits) for background-only multi-kiloton-year exposures, but at a level much less than the 1-$σ$ experiment-to-experiment variation of the 90\% C.L. upper limit on the interaction rate of a 50 GeV/$c^2$ dark matter particle.
description: 15 pages, 14 figures
Predicting poverty and malnutrition for targeting, mapping, monitoring, and early warning
Creators: name: McBride, Linden
name: Barrett, Christopher B.
name: Browne, Christopher
name: Hu, Leiqiu
name: Liu, Yanyan
name: Matteson, David S.
name: Sun, Ying
name: Wen, Jiaming
name: McBride, Linden
name: Barrett, Christopher B.
name: Browne, Christopher
name: Hu, Leiqiu
name: Liu, Yanyan
name: Matteson, David S.
name: Sun, Ying
name: Wen, Jiaming
Publisher: name: Unknown
Year: 2021
Subjects: Food Security and Poverty
Research and Development/Tech Change/Emerging Technologies

description: More frequent and severe shocks combined with more plentiful data and increasingly powerful predictive algorithms heighten the promise of data science in support of humanitarian and development programming. We advocate for embrace of, and investment in, machine learning methods for poverty and malnutrition targeting, mapping, monitoring, and early warning while also cautioning that distinct tasks require different data inputs and methods. In particular, we highlight the differences between poverty and malnutrition targeting and mapping, identification of those in a state of structural versus stochastic deprivation, and the modeling and data challenges of developing early warning systems. Overall, we urge careful consideration of the purpose and possible use cases of big data and machine learning informed models.
Palatini approach and large-scale magnetogenesis
Creators: name: Giovannini, Massimo
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Large-scale magnetogenesis is analyzed within the Palatini approach when the gravitational action is supplemented by a contribution that is nonlinear in the Einstein-Hilbert term. While the addition of the nonlinear terms does not affect the scalar modes of the geometry during the inflationary phase, the tensor-to-scalar ratio is nonetheless suppressed. In this context it is plausible to have a stiff phase following the standard inflationary stage provided the potential has a quintessential form. The large-scale magnetic fields can even be a fraction of the nG over typical length scales of the order of the Mpc prior to the gravitational collapse of the protogalaxy.
description: 41 pages, 5 figures; corrected typos to match the version to be published in JCAP
Crossing the Phantom Divide with Parameterized Post-Friedmann Dark Energy
Creators: name: Fang, Wenjuan
name: Hu, Wayne
name: Lewis, Antony
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Dark energy models with a single scalar field cannot cross the equation of state divide set by a cosmological constant. More general models that allow crossing require additional degrees of freedom to ensure gravitational stability. We show that a parameterized post-Friedmann description of cosmic acceleration provides a simple but accurate description of multiple scalar field crossing models. Moreover the prescription provides a well controlled approximation for a wide range of "smooth" dark energy models. It conserves energy and momentum and is exact in the metric evolution on scales well above and below the transition scale to relative smoothness. Standard linear perturbation tools have been altered to include this description and made publicly available for studies of the dark energy involving cosmological structure out to the horizon scale.
description: 4 pages, 2 figures, code available at http://camb.info/ppf, minor revisions reflect PRD published version
Probabilistic causal processes
Creators: name: Katz, Jonathan Richard
Publisher: name: University of British Columbia
Year: 2010

description: Many theorists take causality to be the heart of scientific explanation. If we couple this view with the idea, again common enough, that causes are something like sufficient conditions for their effects, then we have raised a difficulty for any theory of scientific explanation that admits "final" (genuine) statistical explanations, for a statistical explanation must allow that factors relevant to an event to be explained need not determine that event, but only make it probable to some degree (other than zero or one). If we do not wish to give up the possibility of genuine statistical explanations we must either (1) give up this central causal intuition in explanation, or (2) admit that causes act as something other than sufficient conditions — say in a probabilistic manner. This is, of course, little help unless we can clearly explicate the notion of a probabilistic cause, one of the tasks I have attempted to accomplish in this thesis. The general structure of this effort is in three parts. In the first chapter I generate the basic concepts underlying the notion of a probabilistic cause. In this I follow closely the development of this idea as constructed by Wesley Salmon. Within this view scientific explanation consists in the tracing of causal influence via causes as processes, and in providing the probability relations among events which are the product of causal interactions. In the second chapter I further develop the idea of causal processes by comparing this notion with the more traditional analyses of causation, the regularity and counterfactual theories. There I show how the process ontology very naturally overcomes problems in both of these views. I also note the advantages this conception of causes holds over these received views with respect to the problem of determinism. In the third and final chapter I discuss, and attempt to overcome, difficulties that are specific to the notion of a probabilistic causal process.
Cephennium hypogaeum NORMAND 1906
Creators: name: Assing, Volker
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Cephennium
Cephennium hypogaeum

description: Cephennium hypogaeum NORMAND, 1906 (Map 2)
Material examined by C. Besuchet (unpubl.): SPAIN: Cataluña: 1♂, Sant Pere Pescador, XII.1953, leg. Zariquiey ("Mus. Barcelone").
This anophthalmous species is known from few localities in Pyrénées-Orientales (France) and Gerona (Spain) (Map 2). For illustrations of the aedeagus see OROUSSET (2018).
description: Published as part of Assing, Volker, 2021, On the Cephennium fauna of the Iberian Peninsula and the Atlantic Islands (Coleoptera, Staphylinidae, Scydmaeninae), pp. 891-931 in Linzer biologische Beiträge 52 (2) on page 918, DOI: 10.5281/zenodo.5039032
Single-particle eigenstate thermalization in quantum-chaotic quadratic Hamiltonians
Creators: name: Łydżba, Patrycja
name: Zhang, Yicheng
name: Rigol, Marcos
name: Vidmar, Lev
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the matrix elements of local and nonlocal operators in the single-particle eigenstates of two paradigmatic quantum-chaotic quadratic Hamiltonians; the quadratic Sachdev-Ye-Kitaev (SYK2) model and the three-dimensional Anderson model below the localization transition. We show that they display eigenstate thermalization for normalized observables. Specifically, we show that the diagonal matrix elements exhibit vanishing eigenstate-to-eigenstate fluctuations, and a variance proportional to the inverse Hilbert space dimension. We also demonstrate that the ratio between the variance of the diagonal and the off-diagonal matrix elements is $2$, as predicted by the random matrix theory. We study distributions of matrix elements of observables and establish that they need not be Gaussian. We identify the class of observables for which the distributions are Gaussian.
Cephennium catalonicum DODERO 1918
Creators: name: Assing, Volker
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Cephennium
Cephennium catalonicum

description: Cephennium catalonicum DODERO, 1918 (Figs 46-47, Map 2)
Material examined by C. Besuchet (unpubl.): SPAIN: Cataluña: 1♂ [syntype], Alella, leg. Zariquiey (coll. Dodero); 1♂ [syntype], Moncada, leg. Zariquiey (MCSNG); 1♂, Barcelona, Centelles, Mas de Xaxars (coll. Binaghi); 1♂, 1♀, N Barcelona, Granollers env., La Roca, leg. Franz (NHMW); 1♂, Prov. Barcelona, Cibidalo [?], leg. Coiffait (MHNG).
The original description is based on two males from "Alella et Moncada" (DODERO 1918). This species has been reported only from Cataluña, Northeast Spain. The aedeagus is illustrated in Figs 46-47, based on Besuchet (unpubl.).
description: Published as part of Assing, Volker, 2021, On the Cephennium fauna of the Iberian Peninsula and the Atlantic Islands (Coleoptera, Staphylinidae, Scydmaeninae), pp. 891-931 in Linzer biologische Beiträge 52 (2) on page 918, DOI: 10.5281/zenodo.5039032
U(1) Mediation of Flux Supersymmetry Breaking
Creators: name: Grimm, Thomas W.
name: Klemm, Albrecht
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the mediation of supersymmetry breaking triggered by background fluxes in Type II string compactifications with N=1 supersymmetry. The mediation arises due to an U(1) vector multiplet coupling to both a hidden supersymmetry breaking flux sector and a visible D-brane sector. The required internal manifolds can be constructed by non-Kaehler resolutions of singular Calabi-Yau manifolds. The effective action encoding the U(1) coupling is then determined in terms of the global topological properties of the internal space. We investigate suitable local geometries for the hidden and visible sector in detail. This includes a systematic study of orientifold symmetries of del Pezzo surfaces realized in compact geometries after geometric transition. We construct compact examples admitting the key properties to realize flux supersymmetry breaking and U(1) mediation. Their toric realization allows us to analyze the geometry of curve classes and confirm the topological connection between the hidden and visible sector.
description: 63 pages, 4 figures
An effective field theory approach for the $S = 3/2$ bilayer honeycomb antiferromagnet
Creators: name: Acevedo, S.
name: Lamas, C. A.
name: Pujol, P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The spin-3/2 Heisenberg antiferromagnet on the bilayer honeycomb lattice is a minimal model to describe the magnetic behavior of Bi$_3$Mn$_4$O$_{12}$(NO$_3$). We study this model with frustrating inter-layer second-neighbor couplings, taking into account quantum and thermal fluctuations. We use a path integral formulation in terms of coherent states to describe the low energy physics of the model. We show that for a particular point in the parameter space, close to the experimental estimated couplings, a continuum classical degeneracy is lifted by both quantum and thermal fluctuations, and a collinear state is then selected by an order by disorder mechanism. Our results provide a global perspective in the understanding of the experimental observations.
Vector-valued Gaussian Processes on Riemannian Manifolds via Gauge Independent Projected Kernels
Creators: name: Hutchinson, Michael
name: Terenin, Alexander
name: Borovitskiy, Viacheslav
name: Takao, So
name: Teh, Yee Whye
name: Deisenroth, Marc Peter
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Gaussian processes are machine learning models capable of learning unknown functions in a way that represents uncertainty, thereby facilitating construction of optimal decision-making systems. Motivated by a desire to deploy Gaussian processes in novel areas of science, a rapidly-growing line of research has focused on constructively extending these models to handle non-Euclidean domains, including Riemannian manifolds, such as spheres and tori. We propose techniques that generalize this class to model vector fields on Riemannian manifolds, which are important in a number of application areas in the physical sciences. To do so, we present a general recipe for constructing gauge independent kernels, which induce Gaussian vector fields, i.e. vector-valued Gaussian processes coherent with geometry, from scalar-valued Riemannian kernels. We extend standard Gaussian process training methods, such as variational inference, to this setting. This enables vector-valued Gaussian processes on Riemannian manifolds to be trained using standard methods and makes them accessible to machine learning practitioners.
The Physics of Bodily Tides in Terrestrial Planets, and the Appropriate Scales of Dynamical Evolution
Creators: name: Efroimsky, Michael
name: Lainey, Valery
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Any model of tides is based on a specific hypothesis of how lagging depends on the tidal-flexure frequency. For example, Gerstenkorn (1955), MacDonald (1964), and Kaula (1964) assumed constancy of the geometric lag angle, while Singer (1968) and Mignard (1979, 1980) asserted constancy of the time lag. Thus, each of these two models was based on a certain law of scaling of the geometric lag. The actual dependence of the geometric lag on the frequency is more complicated and is determined by the rheology of the planet. Besides, each particular functional form of this dependence will unambiguously fix the appropriate form of the frequency dependence of the tidal quality factor, Q. Since at present we know the shape of the dependence of Q upon the frequency, we can reverse our line of reasoning and single out the appropriate actual frequency-dependence of the angular lag. This dependence turns out to be different from those employed hitherto, and it entails considerable alterations in the time scales of the tide-generated dynamical evolution. Phobos' fall on Mars is an example we consider.
description: arXiv admin note: substantial text overlap with arXiv:astro-ph/0605521
Pattern recognition in circuit networks
Creators: name: Radke, John D.
Publisher: name: University of British Columbia
Year: 2010

description: This dissertation introduces an analytic approach to the problem of circuit network pattern recognition. The approach involves a two-stage methodology which is described in detail. Initially, a theoretical process is used to generate a bench mark, or yardstick, to which descriptions of form can be oriented; secondly, a link-by-link examination of circuit network structure is undertaken to determine each link's relationship to the bench mark. The graphs composing the bench mark have a continuous structural distribution, ranging from completely connected to rudimentary graphs. A comprehensive description of these graphs is presented, and several properties of the bench mark are examined and compared to those of known families of circuit graphs. It is argued that the bench mark introduced here is more flexible than other yardsticks because its generative process creates a continuous spectrum of graph structures. The internal link-by-link approach also allows comparisons to be made within the link structure of the empirical network and thus an intra-network examination of the network's pattern is possible. Such comparison aids in revealing trends within the link structure of a given empirical circuit network. Finally, an illustration of the application of the proposed approach is presented. Three road networks, all located in western Canada, are chosen as examples of empirical planar networks and the major airline network of Canada is used as a non-planar example.
Ricci Solitons and Einstein-Scalar Field Theory
Creators: name: Akbar, M M
name: Woolgar, E
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: B List has recently studied a geometric flow whose fixed points correspond to static Ricci flat spacetimes. It is now known that this flow is in fact Ricci flow modulo pullback by a certain diffeomorphism. We use this observation to associate to each static Ricci flat spacetime a local Ricci soliton in one higher dimension. As well, solutions of Euclidean-signature Einstein gravity coupled to a free massless scalar field with nonzero cosmological constant are associated to shrinking or expanding Ricci solitons. We exhibit examples, including an explicit family of complete expanding solitons which can be thought of as a Ricci flow for a complete Lorentzian metric. The possible generalization to Ricci-flat stationary metrics leads us to consider an alternative to Ricci flow.
description: 17 pages, 1 figure; Revised version (organizational changes, other minor revisions and corrections, citations corrected and added), to appear in CQG
Laser-assisted kaon decay and CPT symmetry violation
Creators: name: Baouahi, M.
name: Ouali, M.
name: Jakha, M.
name: Mouslih, S.
name: Attaourti, Y.
name: Manaut, B.
name: Taj, S.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we have investigated the charged kaons decay at the lowest order in the presence of a circularly polarized laser field. To be more precise, we have examined the leptonic decay of both positive (matter) and negative (antimatter) kaon which weakly decay via the exchange of $W$ boson. Indeed, we have derived the expression of the leptonic decay width, the leptonic branching ratio, the leptonic ratio and the charged kaon lifetime by using the decay matrix approach. In addition, by using numerical computation, we have presented and discussed how the laser field influences these physical quantities. Moreover, we have analyzed the effect of the laser field on the parameter associated with the CPT symmetry. Then, we have concluded that, in the presence of an electromagnetic field and based on this CPT symmetry parameter, it is possible to control the dominance of matter over antimatter or vice-versa by applying an external field to either violate or conserve the CPT symmetry.
description: 17 pages, 5 figures, 2 tables
$x-$dependence of the quark distribution functions in the $χ$CQM$_{\rm config}$
Creators: name: Dahiya, Harleen
name: Gupta, Manmohan
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Chiral constituent quark model with configuration mixing (\chiCQM_{\rm config}) is known to provide a satisfactory explanation of the ``proton spin problem'' and related issues. In order to enlarge the scope of \chiCQM_{\rm config}, we have attempted to phenomenologically incorporate x-dependence in the quark distribution functions. In particular, apart from calculating valence and sea quark distributions q_{\rm val}(x) and \bar q(x), we have carried out a detailed analysis to estimate the sea quark asymmetries \bar d(x)-\bar u(x), \bar d(x)/\bar u(x) and \frac{\bar d(x)-\bar u(x)}{u(x)-d(x)} as well as spin independent structure functions F_2^p(x)-F_2^n(x) and $F_2^n(x)/F_2^p(x)$ as functions of $x$. We are able to achieve a satisfactory fit for all the above mentioned quantities simultaneously. The inclusion of effects due to configuration mixing have also been examined in the case F_2^p(x)-F_2^n(x) and F_2^n(x)/F_2^p(x) where the valence quark distributions dominate and it is found that it leads to considerable improvement in the results. Further, the valence quark structure has also be tested by extrapolating the predictions of our model in the limit x \to 1 where data is not available.
description: 20 pages, 7 figures. To appear in Eur. Phys. J. C
Making Massless Dirac Fermions from Patterned Two-Dimensional Electron Gases
Creators: name: Park, Cheol-Hwan
name: Louie, Steven G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Analysis of the electronic structure of an ordinary two-dimensional electron gas (2DEG) under an appropriate external periodic potential of hexagonal symmetry reveals that massless Dirac fermions are generated near the corners of the supercell Brillouin zone. The required potential parameters are found to be achievable under or close to laboratory conditions. Moreover, the group velocity is tunable by changing either the effective mass of the 2DEG or the lattice parameter of the external potential, and it is insensitive to the potential amplitude. The finding should provide a new class of systems other than graphene for investigating and exploiting massless Dirac fermions using 2DEGs in semiconductors.
description: 5 pages, 4 figures, significant revision of abstract, text, and figures
Challenges of Lattice Calculation of Scalar Mesons
Creators: name: Liu, Keh-Fei
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: I review a proposed pattern of the light scalar mesons with q\bar{q} mesons and glueball above 1 GeV and tetraquark mesoniums below 1 GeV. Several challenges and caveats of calculating these light scalar mesons with dynamical fermions are discussed.
description: typos corrected, 6 pages, 2 figures; Contribution to the proceedings of the Workshop on Scalar Mesons and Related Topics, honouring the 70th birthday of Michael Scadron, Lisbon, Portugal, Feb. 11-16, 2008
Compressibility and equation of state of finite nuclei
Creators: name: Umar, A. S.
name: Oberacker, V. E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present a new approach for calculating the nuclear equation of state and compressibility for finite nuclei using the density-constrained Hartree-Fock method.
description: 4 pages, 3 figures
Impurities in ultracold quantum gases: from polaron formation to mediated interactions
Creators: name: Jager, Jonas Hugo
Publisher: name: Imperial College London
Year: 2022

description: In this thesis, we investigate the properties of Bose polarons in various settings. The overarching theme of this work is that, in contrast to many existing treatments of the Bose polaron, we apply semi-classical methods from first principles. Most of this thesis is based on [JJ1,JJ2,JJ3,JJ4]. Our first result addresses the Bose polaron in one dimension. We develop a primarily analytical treatment of the one-dimensional Bose polaron, which takes the impurity condensate interaction into account already on the mean-field level. Additionally, we show how to include first-order quantum corrections. Our results show excellent agreement with quasi-exact Quantum Monte Carlo simulations. Motivated by the success of using semi-classical methods, we develop a truncated Wigner like approximation to address out of equilibrium settings. Using the Keldysh path integral formalism, we arrive at a set of differential equations with stochastic initial conditions. This enables us to incorporate quantum fluctuations up to first order and study the impurity dynamics and polaron formation after a sudden quench of the impurity-boson interaction. Subsequently, we turn our attention to a three-dimensional system and again rely on semiclassical approximations to study the condensate mediated interaction between two impurities. The two impurities can form a bound state called the bipolaron for sufficiently large mediated interactions. We discuss how standard methods lead to inadequate results and show how these limitations can be remedied by correctly accounting for boson-boson interaction. We calculate the shape of the mediated interaction potential and the ground state of the two impurities, thus characterising the bipolaron formation. Thereafter, we point out the similarities between the semi-classical approximations of the polaron problem considered so far and colloids interacting with a fluctuating field. We develop a general framework that perturbatively treats a broad class of field theories and arrive at an effective action only depending on the impurity degrees of freedom. We apply this approach to model A and find good agreement with simulations of the full system in the perturbative regime.
Convergent Iterative Solutions of Schroedinger Equation for a Generalized Double Well Potential
Creators: name: Friedberg, R.
name: Lee, T. D.
name: Zhao, W. Q.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present an explicit convergent iterative solution for the lowest energy state of the Schroedinger equation with a generalized double well potential $V=\frac{g^2}{2}(x^2-1)^2(x^2+a)$. The condition for the convergence of the iteration procedure and the dependence of the shape of the groundstate wave function on the parameter $a$ are discussed.
description: 23 pages, 7 figures
ROD: Reception-aware Online Distillation for Sparse Graphs
Creators: name: Zhang, Wentao
name: Jiang, Yuezihan
name: Li, Yang
name: Sheng, Zeang
name: Shen, Yu
name: Miao, Xupeng
name: Wang, Liang
name: Yang, Zhi
name: Cui, Bin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Graph neural networks (GNNs) have been widely used in many graph-based tasks such as node classification, link prediction, and node clustering. However, GNNs gain their performance benefits mainly from performing the feature propagation and smoothing across the edges of the graph, thus requiring sufficient connectivity and label information for effective propagation. Unfortunately, many real-world networks are sparse in terms of both edges and labels, leading to sub-optimal performance of GNNs. Recent interest in this sparse problem has focused on the self-training approach, which expands supervised signals with pseudo labels. Nevertheless, the self-training approach inherently cannot realize the full potential of refining the learning performance on sparse graphs due to the unsatisfactory quality and quantity of pseudo labels. In this paper, we propose ROD, a novel reception-aware online knowledge distillation approach for sparse graph learning. We design three supervision signals for ROD: multi-scale reception-aware graph knowledge, task-based supervision, and rich distilled knowledge, allowing online knowledge transfer in a peer-teaching manner. To extract knowledge concealed in the multi-scale reception fields, ROD explicitly requires individual student models to preserve different levels of locality information. For a given task, each student would predict based on its reception-scale knowledge, while simultaneously a strong teacher is established on-the-fly by combining multi-scale knowledge. Our approach has been extensively evaluated on 9 datasets and a variety of graph-based tasks, including node classification, link prediction, and node clustering. The result demonstrates that ROD achieves state-of-art performance and is more robust for the graph sparsity.