cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Control and Simulation of Motion of Constrained Multibody Systems Based on Projection Matrix Formulation
Creators: name: Aghili, Farhad
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: This paper presents a unified approach for inverse and direct dynamics of constrained multibody systems that can serve as a basis for analysis, simulation, and control. The main advantage of the formulation of the dynamic is that it does not require the constraint equations to be linearly independent. Thus, a simulation may proceed even in the presence of redundant constraints or singular configurations and a controller does not need to change its structure whenever the mechanical system changes its topology or number of degrees of freedom. A motion control scheme is proposed based on a projected inverse-dynamics scheme which proves to be stable and minimizes the weighted Euclidean norm of the actuation force. The projection-based control scheme is further developed for constrained systems, e.g. parallel manipulators, which have some joints with no actuators (passive joints). This is complemented by the development of constraint force control. A condition on the inertia matrix resulting in a decoupled mechanical system is analytically derived which simplifies the implementation of the force control.
title: Towards an improvement of the legal framework governing Occupational Health and Safety in the European Union
Creators: name: Cefaliello, Aude
Publisher: name: University of Glasgow
Year: 2020
Subjects: subject: European Labour Law - Comparative Law - Occupational Health and Safety - Labour Law - European Union

description: This thesis addresses the complex issue of what action could be taken by the EU to improve OHS standards across the Member States (MS). More specifically: what can be done at the EU level? Why should action be taken and under what conditions? To address these questions, the thesis is structured around two main focal points: in order to think about what could be done to develop EU OHS standards, it is first necessary to assess what has been done in the past. In the first chapter, a socio-legal perspective is adopted to chart the evolution to date of OHS law within the EU. Relevant primary sources are analysed, including all EU OHS directives, and a review of the secondary literature is complemented by a series of semi-structured interviews with stakeholders who participated in the drafting or negotiation of the main Framework Directive 89/391/EEC. In order to assess the impact of EU OHS standards within the MS, a comparison is then drawn between French and UK OHS law, with a focus in each case on the changes that were made to national law in response to developments in EU law. In the second part of the thesis, the enquiry turns to consider how the EU institutions might act to improve OHS standards. The jurisprudence of the Court of Justice of the EU (CJEU) is analysed in a detailed, schematic manner and the nature and activities of Labour Inspectorates is considered, both within MS and at the EU level, with a critical review here of the role and function of the recently created European Labour Authority. Given the current political stalemate in the EU in respect of social policy, the main conclusion of the thesis is that the most viable route towards the improvement of workers’ health and safety lies not with new legislation but with the improved application and enforcement of the existing body of EU OHS standards. This could be effected through (i) European-level coordination of the way LIs enforce existing standards at the national level, and (ii) a program of strategic litigation before the CJEU to cover existing gaps and develop ‘new’ rights; for example, the right to reasonable accommodation in the workplace for injured or unwell workers.
Homologous Recombination and Translesion DNA Synthesis Play Critical Roles on Tolerating DNA Damage Caused by Trace Levels of Hexavalent Chromium
Creators: name: Clement, Jean
name: Takata, Minoru
name: Wright, Fred A.
name: Ridpath, John R.
name: Tian, Xu
name: Neo, Dayna
name: Patel, Keyur
name: Zhou, Yi-Hui
name: Takeda, Shunichi
name: Sale, Julian
name: Nakamura, Jun
name: Swenberg, James A.
name: Chen, Youjun
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: Contamination of potentially carcinogenic hexavalent chromium (Cr(VI)) in the drinking water is a major public health concern worldwide. However, little information is available regarding the biological effects of a nanomoler amount of Cr(VI). Here, we investigated the genotoxic effects of Cr(VI) at nanomoler levels and their repair pathways. We found that DNA damage response analyzed based on differential toxicity of isogenic cells deficient in various DNA repair proteins is observed after a three-day incubation with K2CrO4 in REV1-deficient DT40 cells at 19.2 μg/L or higher as well as in TK6 cells deficient in polymerase delta subunit 3 (POLD3) at 9.8 μg/L or higher. The genotoxicity of Cr(VI) decreased ~3000 times when the incubation time was reduced from three days to ten minutes. TK mutation rate also significantly decreased from 6 day to 1 day exposure to Cr(VI). The DNA damage response analysis suggest that DNA repair pathways, including the homologous recombination and REV1- and POLD3-mediated error-prone translesion synthesis pathways, are critical for the cells to tolerate to DNA damage caused by trace amount of Cr(VI).
Suppression of one-dimensional weak localization by band asymmetry
Creators: name: Arora, Kartikeya
name: Singh, Rajeev
name: Hosur, Pavan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate disorder-induced localization in metals that break time-reversal and inversion symmetries through their energy dispersion, $ε_{k}\neqε_{-k}$, but lack Berry phases. In the perturbative regime of disorder, we show that weak localization is suppressed due to a mismatch of the Fermi velocities of left and right movers. To substantiate this analytical result, we perform quench numerics on chains shorter than the Anderson localization length -- the latter computed and verified to be finite using the recursive Green's function method -- and find a sharp rise in the saturation value of the participation ratio due to band asymmetry, indicating a tendency to delocalize. Interestingly, for weak disorder strength $η$, we see a better fit to the scaling behavior $ξ\propto1/η^{2}$ for asymmetric bands than conventional symmetric ones.
description: Added scaling of localization length with weak disorder
Universal signatures of singularity-resolving physics in photon rings of black holes and horizonless objects
Creators: name: Eichhorn, Astrid
name: Held, Aaron
name: Johannsen, Philipp-Vincent
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Within quantum-gravity approaches and beyond, different mechanisms for singularity resolution in black holes exist. Under a set of assumptions that we spell out in detail, these mechanisms leave their imprint in shadow images of spherically symmetric black holes. We find that even current EHT accuracy is sufficient to place nontrivial constraints on the scale of new physics within one modified spacetime, if the EHT measurement of M87* is combined with an independent measurement of the black-hole mass. In other spacetimes, increased accuracy is required that the next-generation EHT may deliver. We show how the combination of $n=1$ and $n=2$ photon rings is a powerful probe of the spacetime geometry of regular black holes, even when considering astrophysical uncertainties in accretion disks. Further, we generate images containing a localized emission region, inspired by the idea of hotspots in accretion flows. Finally, we investigate the photon-ring structure of a horizonless object, which is characterized by either two or no photon spheres. We show how photon rings annihilate each other, when there is no photon sphere in the spacetime.
description: 26 pages + appendix; 12 figures
Fermion-like behavior of elements in their spatial distribution around points of interest
Creators: name: Martinez-Perdiguero, Josu
Publisher: name: arXiv
Year: 2024
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: In this paper we analyze the spatial distribution of elements around points of interest. Based on a spatial exclusion principle we model the system by means of a Fermi-Dirac distribution defined by two easily interpretable parameters. By means of image analysis, two real cases are studied and compared to the theory: people in an open-air concert and cars in a mall parking-lot. We show that they closely obey the proposed fermion-like statistics.
Diphyodus longirostris
Creators: name: Lambe L., M.
Publisher: name: Zenodo
Year: 1902
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Aspidorhynchiformes
Aspidorhynchidae
Diphyodus
Diphyodus longirostris

description: The bone figured on the above plate affords evidence of the complete coalescence of the premaxillaj in a fish to form a long, slender, snout armed with teeth that succeeded each other in a regular alternating manner. These characters have suggested the names of the genus and species proposed. The specimen is in the form of a comparatively thick plate bent, on itself, so as to be U-shaped in transverse section; it is imperfect at both ends, is 23 mm. long, tapers slightly toward the from, and is 4 mm. broad posteriorly and 3'5 mm. broad at its anterior end. There is no evidence of a median longitudinal suture. The sides of the hollow semi-cylin- der thus formed, are slightly over 1 mm. thick, but the thickness of the basal part is over 2 mm. On the flattened upper surface of the two sides, are preserved, circular bases of teeth, anchylosed to the bone, that appear as raised circles, averaging '80 mm. in diameter and aboixt 2 mm. apart from centre to centre. On the right side there are nine teeth represented at equal intervals, but on the left side, although there were a like number of teeth, the interspaces are not so regular. Shallow subquadrangular depressions, varying in number from one to three, according to the length of the interspace, occur between the tooth-bases. Each depression represents the former position of a tooth that has fallen out or has been broken off. A circle of minute pits or foramina surrounds each tooth-base; similar but less regular pits occur in the intervening depresssions and a few are observed within the tooth-bases themseh'es. Two tubular canals, placed side by side, above the centre of the base, pierce the bone longitudinally throughout its length. The bottom of the median groove between the two rows of teeth has an undulating surface. The sides and rounded base of the bone are smooth and show irregular longitudinal lines of small pit-like markings. One of the tooth-bases at the posterior end is decidedly subquadrangular or oval in shape with its larger diameter transverse. Two or three fragments present the same characteristics of structure. Belly River series, Red Deer rive:, 1901.
description: Published as part of Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), pp. 25-81 in Geological Survey of Canada Contributions to Canadian Palaeontology 3 on page 30, DOI: 10.5281/zenodo.3233762
title: Miniaturized guided wave structures and applications
Creators: name: Xu, Ruo Feng
Publisher: name: University of Kent
Year: 2022

description: This thesis examines the properties of novel transmission lines and waveguides as well as their practical applications. The research begins with a discussion of metamaterial transmission lines. Two new composite right/left-handed designs formed in shielded striplines are presented and shown to have great left-handed bands. In the waveguides research, we demonstrate the multilayer, narrowband and half-mode folded waveguide with the benefit of guide miniaturization. Due to the almost half metallic surface reduction of half-mode waveguide, a novel planar half-mode substrate integrated waveguide is presented and its properties are analyzed. It has the great integration with planar components and stops the radiation of conventional open waveguides. One application based on this medium is a novel switchable substrate waveguide that can be switched between two types of mode via the biasing of pin diodes. Another application is a tunable phase shifter that has a maximum phase shift of 50 degrees with acceptable insertion loss. A theoretical method for the analysis of planar half-mode waveguides using transverse resonance technique is introduced in this thesis. This method is used to locate the cut-off frequency of the waveguide and analyse the equivalent circuit loaded with discrete components. This novel technique has the advantage of simplicity and compares well with results of electromagnetic simulation and measurement.
Geant4 Modeling of a Cerium Bromide Scintillator Detector for the IMPRESS CubeSat Mission
Creators: name: Setterberg, William
name: Glesener, Lindsay
name: Egziabher, Demoz Gebre
name: Sample, John G.
name: Smith, David M.
name: Caspi, Amir
name: Faulkner, Allan
name: Clemmer, Lestat
name: Hildebrandt, Kate
name: Skinner, Evan
name: Greathouse, Annsley
name: Kozic, Ty
name: Wieber, Meredith
name: Savadogo, Mansour
name: Nightingale, Mel
name: Knuth, Trevor
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Solar flares are some of the most energetic events in the solar system and can be studied to investigate the physics of plasmas and stellar processes. One interesting aspect of solar flares is the presence of accelerated (nonthermal) particles, whose signatures appear in solar flare hard X-ray emissions. Debate has been ongoing since the early days of the space age as to how these particles are accelerated, and one way to probe relevant acceleration mechanisms is by investigating short-timescale (tens of milliseconds) variations in solar flare hard X-ray flux. The Impulsive Phase Rapid Energetic Solar Spectrometer (IMPRESS) CubeSat mission aims to measure these fast hard X-ray variations. In order to produce the best possible science data from this mission, we characterize the IMPRESS scintillator detectors using Geant4 Monte Carlo models. We show that the Geant4 Monte Carlo detector model is consistent with an analytical model. We find that Geant4 simulations of X-ray and optical interactions explain observed features in experimental data, but do not completely account for our measured energy resolution. We further show that nonuniform light collection leads to double-peak behavior at the 662 keV $^{137}$Cs photopeak and can be corrected in Geant4 models and likely in the lab.
description: 12 pages, 9 figures. SPIE 2022 Astronomical Telescopes and Instrumentation proceedings paper
Quantum Hall Physics with Cold Atoms in Cylindrical Optical Lattices
Creators: name: Łącki, Mateusz
name: Pichler, Hannes
name: Sterdyniak, Antoine
name: Lyras, Andreas
name: Lembessis, Vassilis E.
name: Al-Dossary, Omar
name: Budich, Jan Carl
name: Zoller, Peter
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose and study various realizations of a Hofstadter-Hubbard model on a cylinder geometry with fermionic cold atoms in optical lattices. The cylindrical optical lattice is created by copropagating Laguerre-Gauss beams, i.e.~light beams carrying orbital angular momentum. By strong focusing of the light beams we create a real space optical lattice in the form of rings, which are offset in energy. A second set of Laguerre-Gauss beams then induces a Raman-hopping between these rings, imprinting phases corresponding to a synthetic magnetic field (artificial gauge field). In addition, by rotating the lattice potential, we achieve a slowly varying flux through the hole of the cylinder, which allows us to probe the Hall response of the system as a realization of Laughlin's thought experiment. We study how in the presence of interactions fractional quantum Hall physics could be observed in this setup.
description: 10 pages, 9 figures
Fault diagnosis for open-circuit faults in NPC inverter based on knowledge-driven and data-driven approaches
Creators: name: Kou, Lei
name: Liu, Chuang
name: Cai, Guo-wei
name: Zhou, Jia-ning
name: Yuan, Quan-de
name: Pang, Si-miao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: I.2
subject: 68T05

description: In this study, the open-circuit faults diagnosis and location issue of the neutral-point-clamped (NPC) inverters are analysed. A novel fault diagnosis approach based on knowledge driven and data driven was presented for the open-circuit faults in insulated-gate bipolar transistors (IGBTs) of NPC inverter, and Concordia transform (knowledge driven) and random forests (RFs) technique (data driven) are employed to improve the robustness performance of the fault diagnosis classifier. First, the fault feature data of AC in either normal state or open-circuit faults states of NPC inverter are analysed and extracted. Second, the Concordia transform is used to process the fault samples, and it has been verified that the slopes of current trajectories are not affected by different loads in this study, which can help the proposed method to reduce overdependence on fault data. Moreover, then the transformed fault samples are adopted to train the RFs fault diagnosis classifier, and the fault diagnosis results show that the classification accuracy and robustness performance of the fault diagnosis classifier are improved. Finally, the diagnosis results of online fault diagnosis experiments show that the proposed classifier can locate the open-circuit fault of IGBTs in NPC inverter under the conditions of different loads.
description: IET Power Electronics
Real-Time Decoding for Fault-Tolerant Quantum Computing: Progress, Challenges and Outlook
Creators: name: Battistel, Francesco
name: Chamberland, Christopher
name: Johar, Kauser
name: Overwater, Ramon W. J.
name: Sebastiano, Fabio
name: Skoric, Luka
name: Ueno, Yosuke
name: Usman, Muhammad
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum computing is poised to solve practically useful problems which are computationally intractable for classical supercomputers. However, the current generation of quantum computers are limited by errors that may only partially be mitigated by developing higher-quality qubits. Quantum error correction (QEC) will thus be necessary to ensure fault tolerance. QEC protects the logical information by cyclically measuring syndrome information about the errors. An essential part of QEC is the decoder, which uses the syndrome to compute the likely effect of the errors on the logical degrees of freedom and provide a tentative correction. The decoder must be accurate, fast enough to keep pace with the QEC cycle (e.g., on a microsecond timescale for superconducting qubits) and with hard real-time system integration to support logical operations. As such, real-time decoding is essential to realize fault-tolerant quantum computing and to achieve quantum advantage. In this work, we highlight some of the key challenges facing the implementation of real-time decoders while providing a succinct summary of the progress to-date. Furthermore, we lay out our perspective for the future development and provide a possible roadmap for the field of real-time decoding in the next few years. As the quantum hardware is anticipated to scale up, this perspective article will provide a guidance for researchers, focusing on the most pressing issues in real-time decoding and facilitating the development of solutions across quantum and computer science.
Identification and Ultrastructural Characterization of a Novel Nuclear Degradation Complex in Differentiating Lens Fiber Cells
Creators: name: Gilliland, Kurt O.
name: Joseph Costello,
name: Johnsen, Sonke
name: Mohamed, Ashik
name: Brennan, Lisa A.
name: Kantorow, Marc
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: An unresolved issue in structural biology is how the encapsulated lens removes membranous organelles to carry out its role as a transparent optical element. In this ultrastructural study, we establish a mechanism for nuclear elimination in the developing chick lens during the formation of the organelle-free zone. Day 12–15 chick embryo lenses were examined by high-resolution confocal light microscopy and thin section transmission electron microscopy (TEM) following fixation in 10% formalin and 4% paraformaldehyde, and then processing for confocal or TEM as described previously. Examination of developing fiber cells revealed normal nuclei with dispersed chromatin and clear nucleoli typical of cells in active ribosome production to support protein synthesis. Early signs of nuclear degradation were observed about 300 μm from the lens capsule in Day 15 lenses where the nuclei display irregular nuclear stain and prominent indentations that sometimes contained a previously undescribed macromolecular aggregate attached to the nuclear envelope. We have termed this novel structure the nuclear excisosome. This complex by confocal is closely adherent to the nuclear envelope and by TEM appears to degrade the outer leaflet of the nuclear envelope, then the inner leaflet up to 500 μm depth. The images suggest that the nuclear excisosome separates nuclear membrane proteins from lipids, which then form multilamellar assemblies that stain intensely in confocal and in TEM have 5 nm spacing consistent with pure lipid bilayers. The denuded nucleoplasm then degrades by condensation and loss of structure in the range 600 to 700 μm depth producing pyknotic nuclear remnants. None of these stages display any classic autophagic vesicles or lysosomes associated with nuclei. Uniquely, the origin of the nuclear excisosome is from filopodial-like projections of adjacent lens fiber cells that initially contact, and then appear to fuse with the outer nuclear membrane. These filopodial-like projections appear to be initiated with a clathrin-like coat and driven by an internal actin network. In summary, a specialized cellular organelle, the nuclear excisosome, generated in part by adjacent fiber cells degrades nuclei during fiber cell differentiation and maturation.
Naringin dihydrochalcone potentially binds to catalytic domain of matrix metalloproteinase-2: molecular docking, MM-GBSA, and molecular dynamics simulation approach
Creators: name: Singh, Atul Kumar
name: Kumar, Shashank
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biophysics
subject: Biochemistry
subject: Pharmacology
subject: Biotechnology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Cancer
subject: Computational Biology

description: Matrix metalloproteinase-2 (MMP2), an extracellular matrix remodulating protein’s increased activity causes cancer-metastasis. Potential MMP2 inhibitors showed sever side-effects in clinical trials. Present study is focused on identification natural MMP2 inhibitor by applying molecular docking, MM-GBSA binding energy estimation and molecular dynamics (MD) simulations. Commercially available flavonoid compound library was used to screen the molecules potentially binding with catalytic domain of MMP2 protein compared to standard MMP2 inhibitor ARP100. Naringin dihydrochalcone (NDC) showed interaction with the important residues (His120, Leu82 and Val117) present at the MMP2 catalytic domain in comparison to known inhibitor ARP100 (dock score ≈ −13 and −8 kcal/mole respectively). Lower ligand-protein binding energy (-67.31 kcal/mole) obtained in MM-GBSA and the MD simulation trajectory analysis showed significant stable and energetically favourable binding of NDC at the catalytic site of MMP2. In conclusion, anti-metastatic potential of NDC should be validated in in vitro and in vivo experiments.
Mass ratio of the 2 pc binary brown dwarf LUH16 and limits on planetary companions from astrometry
Creators: name: Sahlmann, Johannes
name: Lazorenko, Petro F.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We analyse FORS2/VLT $I$-band imaging data to monitor the motions of both components in the nearest known binary brown dwarf WISE J104915.57-531906.1AB (LUH16) over one year. The astrometry is dominated by parallax and proper motion, but with a precision of $\sim$0.2 milli-arcsecond per epoch we accurately measure the relative position change caused by the orbital motion of the pair. This allows us to directly measure a mass ratio of $q=0.78\pm0.10$ for this system. We also search for the signature of a planetary-mass companion around either of the A and B component and exclude at 3-$σ$ the presence of planets with masses larger than $2\,M_\mathrm{Jup}$ and orbital periods of 20--300 d. We update the parallax of LUH16 to $500.51\pm0.11$ mas, i.e. just within 2 pc. This study yields the first direct constraint on the mass ratio of LUH16 and shows that the system does not harbour any close-in giant planets.
description: 6 pages, 7 figures. Accepted for publication in MNRAS letters. Minor changes compared to previous version
Robust Active Visual Perching with Quadrotors on Inclined Surfaces
Creators: name: Mao, Jeffrey
name: Nogar, Stephen
name: Kroninger, Christopher
name: Loianno, Giuseppe
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Autonomous Micro Aerial Vehicles are deployed for a variety tasks including surveillance and monitoring. Perching and staring allow the vehicle to monitor targets without flying, saving battery power and increasing the overall mission time without the need to frequently replace batteries. This paper addresses the Active Visual Perching (AVP) control problem to autonomously perch on inclined surfaces up to $90^\circ$. Our approach generates dynamically feasible trajectories to navigate and perch on a desired target location, while taking into account actuator and Field of View (FoV) constraints. By replanning in mid-flight, we take advantage of more accurate target localization increasing the perching maneuver's robustness to target localization or control errors. We leverage the Karush-Kuhn-Tucker (KKT) conditions to identify the compatibility between planning objectives and the visual sensing constraint during the planned maneuver. Furthermore, we experimentally identify the corresponding boundary conditions that maximizes the spatio-temporal target visibility during the perching maneuver. The proposed approach works on-board in real-time with significant computational constraints relying exclusively on cameras and an Inertial Measurement Unit (IMU). Experimental results validate the proposed approach and shows the higher success rate as well as increased target interception precision and accuracy with respect to a one-shot planning approach, while still retaining aggressive capabilities with flight envelopes that include large excursions from the hover position on inclined surfaces up to 90$^\circ$, angular speeds up to 750~deg/s, and accelerations up to 10~m/s$^2$.
Stable Charged Gravastar model in Cylindrically Symmetric Space-time
Creators: name: Bhattacharjee, D.
name: Chattopadhyay, P. K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, we have extended the idea of gravitational Bose-Einstein condensate star (gravastar) to charged gravastar system and explored the role of charge in gravastar formation and its properties. We have used the most general line element in cylindrically symmetric space-time. In this approach the existence of singularity at the center of gravastar is removed and the event horizon is replaced by the thin shell approximation. The proper length of the shell is calculated along with the energy of the thin shell. A mass limit for thin shell has also been evaluated. The entropy calculation shows that the entropy of the configuration is smaller than that of a quasi-black hole system and even smaller than that of a classical black hole. Unlike black hole, the gravastar system is a stable configuration and there is no information paradox.
description: 12 pages, 4 figures
Cimoliasaurus magnus Leidy 1852
Creators: name: Lambe L., M.
Publisher: name: Zenodo
Year: 1902
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Sauropsida
Plesiosauria
Elasmosauridae
Cimoliasaurus
Cimoliasaurus magnus

description: Cimoliasaurus magnus, Leidy. Cimoliasaurus magnus, Leidy. 1852. Proc. Acad. Nat. Sci. Philadel., vol. v, p. 325, and ibid, 1854 vol. vii, p. J 2, pi. II, figs. 4-6. Cimoliasaurus magnus, Leidy. 1865. Cretaceous Reptiles of the United States, p. 25, pi. v, figs 13-19 and pi. vi, (Smithsonian Contr. to Knowledge, vol. xiv). Fourteen cervical vertebrae, found within a limited space and probably belonging to one individual, are referred to this species; they form a tolerably complete series with a gradual increase in size from front to back. These vertebrae agree with those of the type species in form but are smaller. The centra may be described as shorter than broad, with concave sides and lower surface, articular faces ellipsoidal, sligthly concave with angular margins, costal facet placed low on the sides. Neural arches in all the specimens, broken off, except in one, apparently a late cervical, in which the basal part on one side is preserved, shov,ung the height of the neural canal. The bases of the ribs still remain in a few cases. In the supposed late cervical, the costal facet extends upward on to the base of the neural arch. Two large foramina, placed one on either side of the median line of the lower surface and separated by a low ridge, are connected with a passage that opens into the neural canal by two separate apertures. The neural canal is about as high as it is wide. [table omitted] According to Cope, Discosaurus is specifically identical with this genus. "Whilst under the generic name Cimoliasaurus, Lydekker * has included Brimosaurus, Leidy, and Elasmosaurus and Polycotylus of Cope. Belly River series, Red Deer river, below Berry creek, 1898 and 1901.
description: Published as part of Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), pp. 25-81 in Geological Survey of Canada Contributions to Canadian Palaeontology 3 on pages 32-33, DOI: 10.5281/zenodo.3233762
Non-Gaussian superradiant transition via three-body ultrastrong coupling
Creators: name: Minganti, Fabrizio
name: Garbe, Louis
name: Boité, Alexandre Le
name: Felicetti, Simone
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce a class of quantum optical Hamiltonian characterized by three-body couplings, and propose a circuit-QED scheme based on state-of-the-art technology that implements the considered model. Unlike two-body light-matter interactions, this three-body coupling Hamiltonian is exclusively composed of terms which do not conserve the particle number. We explore the three-body ultrastrong coupling regime, showing the emergence of a superradiant phase transition which is of first order, is characterized by the breaking of a $\mathbb{Z}_2\times \mathbb{Z}_2$ symmetry and has a strongly non-Gaussian nature. Indeed, in contrast to what is observed in any two-body-coupling model, in proximity of the transition the ground state exhibits a divergent coskewness, i.e., quantum correlations that cannot be captured within semiclassical and Gaussian approximations. Furthermore, we demonstrate the robustness of our findings by including dissipative processes in the model, showing that the steady-state of the system inherits from the ground states the most prominent features of the transition.
description: 6+7 pages, 3 figures
Detecting genuine multipartite entanglement in steering scenarios
Creators: name: Jebaratnam, C.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Einstein-Podolsky-Rosen (EPR) steering is a form of quantum nonlocality which is intermediate between entanglement and Bell nonlocality. EPR steering is a resource for quantum key distribution that is device independent on only one side in that it certifies bipartite entanglement when one party's device is not characterized while the other party's device is fully characterized. In this work, we introduce two types of genuine tripartite EPR-steering, and derive two steering inequalities to detect them. In a semi-device-independent scenario where only the dimensions of two parties are assumed, the correlations which violate one of these inequalities also certify genuine tripartite entanglement. It is known that Alice can demonstrate bipartite EPR-steering to Bob if and only if her measurement settings are incompatible. We demonstrate that quantum correlations can also detect tripartite EPR-steering from Alice to Bob and Charlie, even if Charlie's measurement settings are compatible.
description: 8 pages, 1 figure
IgG-Containing Isoforms of Neuregulin-1 Are Dispensable for Cardiac Trabeculation in Zebrafish
Creators: name: Liu, Jiandong
name: Samsa, Leigh Ann
name: Qian, Li
name: Ito, Cade Ellis
name: Brown, Daniel Ross
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: The Neuregulin-1 (Nrg1) signaling pathway has been widely implicated in many aspects of heart development including cardiac trabeculation. Cardiac trabeculation is an important morphogenetic process where clusters of ventricular cardiomyocytes extrude and expand into the lumen of the ventricular chambers. In mouse, Nrg1 isoforms containing an immunoglobulin-like (IgG) domain are essential for cardiac trabeculation through interaction with heterodimers of the epidermal growth factor-like (EGF-like) receptors ErbB2/ErbB4. Recent reports have underscored the importance of Nrg1 signaling in cardiac homeostasis and disease, however, placental development has precluded refined evaluation of the role of this pathway in mammals. ErbB2 has been shown to have a developmentally conserved role in cardiac trabeculation in zebrafish, a vertebrate model organism with completely external development, but the requirement for Nrg1 has not been examined. We found that among the multiple Nrg1 isoforms, the IgG domain-containing, type I Nrg1 (nrg1-I) is the only isoform detectable in the heart. Then, using CRISPR/Cas9 gene editing, we targeted the IgG domain of Nrg1 to produce novel alleles, nrg1nc28 and nrg1nc29, encoding nrg1-I and nrg1-II truncations. Our results indicated that zebrafish deficient for nrg1-I developed trabeculae in an ErbB2-dependent manner. Further, these mutants survive to reproductive adulthood with no overt cardiovascular defects. We also found that additional EGF-like ligands were expressed in the zebrafish heart during development of trabeculae. Together, these results suggest that Nrg1 is not the primary effector of trabeculation and/or that other EGF-like ligand(s) activates the ErbB2/ErbB4 pathway, either through functioning as the primary ligand or acting in a redundant manner. Overall, our work provides an example of cross-species differences in EGF family member requirements for an evolutionary conserved process.
Pretrained Weights for BA-Net of AMOS 2022 Challenge
Creators: name: Hu, Shishuai
name: Liao, Zehui
name: Xia, Yong
Publisher: name: Zenodo
Year: 2022

description: Pretrained Weights for Boundary-Aware Network (BA-Net) of Multi-Modality Abdominal Multi-Organ Segmentation Challenge 2022 (AMOS 2022) Challenge. If you find this useful for your research, please consider citing the paper as follows: @misc{https://doi.org/10.48550/arxiv.2208.13774, doi = {10.48550/ARXIV.2208.13774}, url = {https://arxiv.org/abs/2208.13774}, author = {Hu, Shishuai and Liao, Zehui and Xia, Yong}, title = {Boundary-Aware Network for Abdominal Multi-Organ Segmentation}, publisher = {arXiv}, year = {2022}, }
The impact of thermal noise on kink propagation through a heterogeneous system
Creators: name: Gatlik, Jacek
name: Dobrowolski, Tomasz
Publisher: name: arXiv
Year: 2022
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The impact of thermal noise on kink motion through the curved region of the long Josephson junction is studied. On the basis of the Fokker-Planck equation the analytical formula that describes the probability of transmission of the kink over the potential barrier is proposed. The analytical results are compared with the simulations based on the field model.
description: 20 pages, 5 figures
Data-driven model construction for anisotropic dynamics of active matter
Creators: name: Gu, Mengyang
name: Fang, Xinyi
name: Luo, Yimin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Applications (stat.AP)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The dynamics of cellular pattern formation is crucial for understanding embryonic development and tissue morphogenesis. Recent studies have shown that human dermal fibroblasts cultured on liquid crystal elastomers can exhibit an increase in orientational alignment over time, accompanied by cell proliferation, under the influence of the weak guidance of a molecularly aligned substrate. However, a comprehensive understanding of how this order arises remains largely unknown. This knowledge gap may be attributed, in part, to a scarcity of mechanistic models that can capture the temporal progression of the complex nonequilibrium dynamics during the cellular alignment process. The orientational alignment occurs primarily when cells reach a high density near confluence. Therefore, for accurate modeling, it is crucial to take into account both the cell-cell interaction term and the influence from the substrate, acting as a one-body external potential term. To fill in this gap, we develop a hybrid procedure that utilizes statistical learning approaches to extend the state-of-the-art physics models for quantifying both effects. We develop a more efficient way to perform feature selection that avoids testing all feature combinations through simulation. The maximum likelihood estimator of the model was derived and implemented in computationally scalable algorithms for model calibration and simulation. By including these features, such as the non-Gaussian, anisotropic fluctuations, and limiting alignment interaction only to neighboring cells with the same velocity direction, this model quantitatively reproduce the key system-level parameters--the temporal progression of the velocity orientational order parameters and the variability of velocity vectors, whereas models missing any of the features fail to capture these temporally dependent parameters.
description: 20 pages, 14 figures
Saline bolus for negative contrast perfusion imaging in magnetic particle imaging
Creators: name: Mohn, Fabian
name: Exner, Miriam
name: Szwargulski, Patryk
name: Möddel, Martin
name: Knopp, Tobias
name: Graeser, Matthias
Publisher: name: arXiv
Year: 2023
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: Objective. Magnetic Particle Imaging (MPI) is capable of high temporal resolution measurements of the spatial distribution of magnetic nanoparticles and therefore well suited for perfusion imaging, which is an important tool in medical diagnosis. Perfusion imaging in MPI usually requires a fresh bolus of tracer material to capture the key signal dynamics. Here, we propose a method to decouple the imaging sequence from the injection of additional tracer material, without further increasing the administered iron dose in the body with each image. Approach. A bolus of physiological saline solution without any particles (negative contrast) diminishes the steady-state concentration of a long-circulating tracer during passage. This depression in the measured concentration contributes to the required contrast dynamics. The presence of a long-circulating tracer is therefore a prerequisite to obtain the negative contrast. As a quantitative tracer based imaging method, the signal is linear in the tracer concentration for any location that contains nanoparticles and zero in the surrounding tissue which does not provide any intrinsic signal. After tracer injection, the concentration over time (positive contrast) can be utilized to calculate dynamic diagnostic parameters like perfusion parameters in vessels and organs. Every acquired perfusion image thus requires a new bolus of tracer with a sufficiently large iron dose to be visible above the background. Main results. Perfusion parameters are calculated based on the time response of the proposed negative bolus and compared to a positive bolus. Results from phantom experiments show that normalized signals from positive and negative boli are concurrent and deviations of calculated perfusion maps are low. Significance. Our method opens up the possibility to increase the total monitoring time, while minimizing the iron dose per acquired image.
description: 19 pages, 6 figures
Finding shortest and nearly shortest path nodes in large substantially incomplete networks
Creators: name: Kitsak, Maksim
name: Ganin, Alexander
name: Elmokashfi, Ahmed
name: Cui, Hongzhu
name: Eisenberg, Daniel A.
name: Alderson, David L.
name: Korkin, Dmitry
name: Linkov, Igor
Publisher: name: arXiv
Year: 2022
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Networking and Internet Architecture (cs.NI)
subject: Social and Information Networks (cs.SI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Dynamic processes on networks, be it information transfer in the Internet, contagious spreading in a social network, or neural signaling, take place along shortest or nearly shortest paths. Unfortunately, our maps of most large networks are substantially incomplete due to either the highly dynamic nature of networks, or high cost of network measurements, or both, rendering traditional path finding methods inefficient. We find that shortest paths in large real networks, such as the network of protein-protein interactions (PPI) and the Internet at the autonomous system (AS) level, are not random but are organized according to latent-geometric rules. If nodes of these networks are mapped to points in latent hyperbolic spaces, shortest paths in them align along geodesic curves connecting endpoint nodes. We find that this alignment is sufficiently strong to allow for the identification of shortest path nodes even in the case of substantially incomplete networks. We demonstrate the utility of latent-geometric path-finding in problems of cellular pathway reconstruction and communication security.
In Vitro and In Vivo Characterization of the Alkaloid Nuciferine
Creators: name: Webster, Kevin A.
name: Bernstein, Alison I.
name: Shoichet, Brian K.
name: Gray, Bradley W.
name: Wetsel, William C.
name: Farrell, Martilias S.
name: Doak, Allison K.
name: Rodriguiz, Ramona M.
name: Roth, Bryan L.
name: Huang, Xi-Ping
name: Fantegrossi, William E.
name: Miller, Gary W.
name: White, Kate L.
name: Giguere, Patrick M.
name: Porter, Joseph H.
name: Urban, Daniel J.
name: Gannon, Brenda M.
name: Stout, Kristen A.
name: Park, Su Mi
name: McCorvy, John D.
name: Norwood, Andrew P.
name: Hyatt, William S.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: RationaleThe sacred lotus (Nelumbo nucifera) contains many phytochemicals and has a history of human use. To determine which compounds may be responsible for reported psychotropic effects, we used in silico predictions of the identified phytochemicals. Nuciferine, an alkaloid component of Nelumbo nucifera and Nymphaea caerulea, had a predicted molecular profile similar to antipsychotic compounds. Our study characterizes nuciferine using in vitro and in vivo pharmacological assays.MethodsNuciferine was first characterized in silico using the similarity ensemble approach, and was followed by further characterization and validation using the Psychoactive Drug Screening Program of the National Institute of Mental Health. Nuciferine was then tested in vivo in the head-twitch response, pre-pulse inhibition, hyperlocomotor activity, and drug discrimination paradigms.ResultsNuciferine shares a receptor profile similar to aripiprazole-like antipsychotic drugs. Nuciferine was an antagonist at 5-HT2A, 5-HT2C, and 5-HT2B, an inverse agonist at 5-HT7, a partial agonist at D2, D5 and 5-HT6, an agonist at 5-HT1A and D4 receptors, and inhibited the dopamine transporter. In rodent models relevant to antipsychotic drug action, nuciferine blocked head-twitch responses and discriminative stimulus effects of a 5-HT2A agonist, substituted for clozapine discriminative stimulus, enhanced amphetamine induced locomotor activity, inhibited phencyclidine (PCP)-induced locomotor activity, and rescued PCP-induced disruption of prepulse inhibition without induction of catalepsy.ConclusionsThe molecular profile of nuciferine was similar but not identical to that shared with several approved antipsychotic drugs suggesting that nuciferine has atypical antipsychotic-like actions.
Efficient Document Retrieval by End-to-End Refining and Quantizing BERT Embedding with Contrastive Product Quantization
Creators: name: Qiu, Zexuan
name: Su, Qinliang
name: Yu, Jianxing
name: Si, Shijing
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Efficient document retrieval heavily relies on the technique of semantic hashing, which learns a binary code for every document and employs Hamming distance to evaluate document distances. However, existing semantic hashing methods are mostly established on outdated TFIDF features, which obviously do not contain lots of important semantic information about documents. Furthermore, the Hamming distance can only be equal to one of several integer values, significantly limiting its representational ability for document distances. To address these issues, in this paper, we propose to leverage BERT embeddings to perform efficient retrieval based on the product quantization technique, which will assign for every document a real-valued codeword from the codebook, instead of a binary code as in semantic hashing. Specifically, we first transform the original BERT embeddings via a learnable mapping and feed the transformed embedding into a probabilistic product quantization module to output the assigned codeword. The refining and quantizing modules can be optimized in an end-to-end manner by minimizing the probabilistic contrastive loss. A mutual information maximization based method is further proposed to improve the representativeness of codewords, so that documents can be quantized more accurately. Extensive experiments conducted on three benchmarks demonstrate that our proposed method significantly outperforms current state-of-the-art baselines.