cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The 3-D structure of the Virgo cluster from H band Fundamental Plane and Tully-Fisher distance determinations
Creators: name: Gavazzi, G.
name: Boselli, A.
name: Scodeggio, M.
name: Pierini, D.
name: Belsole, E.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We undertook a surface photometry survey of 200 galaxies in the Virgo cluster (complete to B<14.0 mag) carried out in the near-Infrared (NIR) H band. Combining velocity dispersion measurements from the literature with new spectroscopic data for 11 galaxies we derive distances of 59 early type galaxies using the Fundamental Plane (FP) method. The distance of another 75 late-type galaxies is determined using the Tully-Fisher (TF) method. For this purpose we use the maximum rotational velocity, as derived from HI spectra from the literature, complemented with new H_alpha rotation curves of 8 highly HI deficient galaxies. The zero-point of the FP and TF template relations are calibrated assuming the distance modulus of Virgo mu_o=31.0, as determined with the Cepheids method. Using these 134 distance determinations (with individual uncertainties of 0.35 (TF), 0.45 (FP) mag) we find that the distance of cluster A, associated with M87, is mu_o=30.84+-0.06. Cluster B, off-set to the south, is found at mu_o=31.84+-0.10$. This subcluster is falling onto A at about 750 km/sec. Clouds W and M are at twice the distance of A. Galaxies on the North-West and South-East of the main cluster A belong to two clouds composed almost exclusively of spiral galaxies with distances consistent with A, but with significantly different velocity distributions, suggesting that they are falling onto cluster A at approximately 770 km/sec from the far-side and at 200 km/sec from the near-side respectively. The mass of Virgo inferred from the peculiar motions induced on its vicinity is consistent with the virial expectation.
description: 11 pages, 10 postscript figures, 4 tables (create a ps landscape file for MY328t2a.tex); accepted for publication in MNRAS
title: ADCO, Cartulaire de l'abbaye de Cîteaux dit Cartulare Antiquum t.3 (2e moitié XIIIe siècle), Cart. 168 (11 H 66), f. 0133r
Creators: name: de la Côte d'Or, Archives départementales
name: Archives Départementales De La Côte-D'Or
name: Petot, Frédérique
name: Projet CBMA
name: CG21/F.PETOT/2010
name: Petot, Frédéric
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2020
Subjects: subject: cartulaire
subject: Corpus Burgundiae Medii Aevi
subject: Chartes de la Bourgogne du Moyen Âge
subject: LaMOP
subject: Laboratoire de Médiévistique Occidentale de Paris

description: Cartulaire de l'abbaye de Cîteaux dit Cartulare Antiquum t.3 (2e moitié XIIIe siècle), Archives départementales de la Côte-d'Or, Cart. 168 (11 H 66), f. 0133r, Numérisation en mode image.
description: Relation: http://www.cbma-project.eu/
description: Bibliographic citation: Cartulaire de l'abbaye de Cîteaux dit Cartulare Antiquum t.3 (2e moitié XIIIe siècle), Archives départementales de la Côte-d'Or, Cart. 168 (11 H 66), f. 0133r, in Projet CBMA - Corpus Burgundiae Medii Aevi [Ressource en ligne], https:// manuscrits.cbma-project.eu/
description: Provenance: https://www.geonames.org/3024876
description: Provenance: http://www.idref.fr/030974844/id
description: Provenance: https://catalogue.bnf.fr/ark:/12148/cb12228351v
description: Provenance: abbaye de Cîteaux
description: Provenance: http://www.wikidata.org/entity/Q843261
title: Data analysis and uncertainty estimation in supercontinuum laser absorption spectroscopy
Creators: name: Emmert, Johannes
name: Blume, Niels Göran
name: Dreizler, Andreas
name: Wagner, Steven
Publisher: name: Springer Nature
Year: 2022

description: A set of algorithms is presented that facilitates the evaluation of super continuum laser absorption spectroscopy (SCLAS) measurements with respect to temperature, pressure and species concentration without the need for simultaneous background intensity measurements. For this purpose a non-linear model fitting approach is employed. A detailed discussion of the influences on the instrument function of the spectrometer and a method for the in-situ determination of the instrument function without additional hardware are given. The evaluation procedure is supplemented by a detailed measurement precision assessment by applying an error propagation through the non-linear model fitting approach. While the algorithms are tailored to SCLAS, they can be transferred to other spectroscopic methods, that similarly require an instrument function. The presented methods are validated using gas cell measurements of methane in the near infrared region at pressures up to 8.7 bar.
Polyp-PVT: Polyp Segmentation with Pyramid Vision Transformers
Creators: name: Dong, Bo
name: Wang, Wenhai
name: Fan, Deng-Ping
name: Li, Jinpeng
name: Fu, Huazhu
name: Shao, Ling
Publisher: name: arXiv
Year: 2021
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Most polyp segmentation methods use CNNs as their backbone, leading to two key issues when exchanging information between the encoder and decoder: 1) taking into account the differences in contribution between different-level features and 2) designing an effective mechanism for fusing these features. Unlike existing CNN-based methods, we adopt a transformer encoder, which learns more powerful and robust representations. In addition, considering the image acquisition influence and elusive properties of polyps, we introduce three standard modules, including a cascaded fusion module (CFM), a camouflage identification module (CIM), and a similarity aggregation module (SAM). Among these, the CFM is used to collect the semantic and location information of polyps from high-level features; the CIM is applied to capture polyp information disguised in low-level features, and the SAM extends the pixel features of the polyp area with high-level semantic position information to the entire polyp area, thereby effectively fusing cross-level features. The proposed model, named Polyp-PVT, effectively suppresses noises in the features and significantly improves their expressive capabilities. Extensive experiments on five widely adopted datasets show that the proposed model is more robust to various challenging situations (e.g., appearance changes, small objects, rotation) than existing representative methods. The proposed model is available at https://github.com/DengPingFan/Polyp-PVT.
description: Accepted to CAAI AIR 2023
Infrared galaxies
Creators: name: Blain, Andrew W.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: To study large-scale structure in the Universe a full census of the contents are required. This is even more important when the processes of galaxy formation are being investigated. In the last year the population of distant galaxies that emit most of their energy in the infrared waveband have been studied in unprecedented detail. The intensity of background radiation at wavelengths between 3 mm and 10 microns has been determined to within a factor of about 2, and much of this background radiation has been resolved into individual galaxies. These galaxies are largely hidden from view in the optical waveband by absorption due to interstellar dust. By combining this new knowledge with the ever growing body of information gathered using optical telescopes, the process of galaxy formation is slowly being revealed. Great opportunities for studying the distant Universe are promised by advances in instrumentation in the millimeter (mm), submm and far-infrared wavebands over the next decade.
description: 8 pages, 3 figures. To appear in `Particle Physics and the Early Universe (COSMO-98)', AIP Press
Exact Spectral Form Factor in a Minimal Model of Many-Body Quantum Chaos
Creators: name: Bertini, Bruno
name: Kos, Pavel
name: Prosen, Tomaz
Publisher: name: arXiv
Year: 2018
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The most general and versatile defining feature of quantum chaotic systems is that they possess an energy spectrum with correlations universally described by random matrix theory (RMT). This feature can be exhibited by systems with a well defined classical limit as well as by systems with no classical correspondence, such as locally interacting spins or fermions. Despite great phenomenological success, a general mechanism explaining the emergence of RMT without reference to semiclassical concepts is still missing. Here we provide the example of a quantum many-body system with no semiclassical limit (no large parameter) where the emergence of RMT spectral correlations is proven exactly. Specifically, we consider a periodically driven Ising model and write the Fourier transform of spectral density's two-point function, the spectral form factor, in terms of a partition function of a two-dimensional classical Ising model featuring a space-time duality. We show that the self-dual cases provide a minimal model of many-body quantum chaos, where the spectral form factor is demonstrated to match RMT for all values of the integer time variable $t$ in the thermodynamic limit. In particular, we rigorously prove RMT form factor for odd $t$, while we formulate a precise conjecture for even $t$. The results imply ergodicity for any finite amount of disorder in the longitudinal field, rigorously excluding the possibility of many-body localization. Our method provides a novel route for obtaining exact nonperturbative results in non-integrable systems.
description: 6 + 22 pages, 3 figures; v2: improved presentation of the proofs in the appendices; v3: as appears in Physical Review Letters
A Mid-Infrared Imaging Survey of Proto-Planetary Nebula Candidates
Creators: name: Meixner, Margaret
name: Ueta, Toshiya
name: Dayal, Aditya
name: Hora, Joseph L.
name: Fazio, Giovanni
name: Hrivnak, Bruce J.
name: Skinner, Christopher J.
name: Hoffmann, William F.
name: Deutsch, Lynn K.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the data from a mid-infrared imaging survey of 66 proto-planetary nebula candidates using two mid-IR cameras (MIRAC2 and Berkcam) at the NASA Infrared Telescope Facility and the United Kingdom Infrared Telescope. The goal of this survey is to determine the size, flux, and morphology of the mid-IR emission regions, which sample the inner regions of the circumstellar dust shells of proto-planetary nebulae. We imaged these proto-planetary nebulae with narrow-band filters ($Δλ/ λ\sim 10%$) at wavelengths of notable dust features. With our typical angular resolution of 1\arcsec, we resolve 17 sources, find 48 objects unresolved, and do not detect 1 source. For several sources, we checked optical and infrared associations and positions of the sources. In table format, we list the size and flux measurements for all the detected objects and show figures of all the resolved sources. Images for all the detected objects are available on line in FITS format from the Astronomy Digital Image Library at the National Center for Supercomputing Application. The proto-planetary nebula candidate sample includes, in addition to the predominant proto-planetary nebulae, extreme asymptotic giant branch stars, young planetary nebulae, a supergiant, and a luminous blue variable. We find that dust shells which are cooler ($\rm T \sim 150$ K) and brighter in the infrared are more easily resolved. Eleven of the seventeen resolved sources are extended and fall into one of two types of mid-IR morphological classes: core/elliptical or toroidal. Core/elliptical structures show unresolved cores with lower surface brightness elliptical nebulae. Toroidal structures show limb-brightened peaks suggesting equatorial density enhancements. We argue that core/ellipticals have denser dust shells than toroidals.
description: 32 pages, 5 tables, 2 e/ps figures (fig3 is available through ADIL [see text]), to be published in ApJS May 1999 issue
Deterministic approximation schemes with computable errors for the distributions of Markov chains
Creators: name: Kuntz Nussio, Juan
Publisher: name: Imperial College London
Year: 2017

description: This thesis is a monograph on Markov chains and deterministic approximation schemes that enable the quantitative analysis thereof. We present schemes that yield approximations of the time-varying law of a Markov chain, of its stationary distributions, and of the exit distributions and occupation measures associated with its exit times. In practice, our schemes reduce to solving systems of linear ordinary differential equations, linear programs, and semidefinite pro- grams. We focus on the theoretical aspects of these schemes, proving convergence and providing computable error bounds for most of them. To a lesser extent, we study their practical use, applying them to a variety of examples and discussing the numerical issues that arise in their implementation.
Higher-order heat equation and the Gelfand-Dickey hierarchy
Creators: name: Iliev, Plamen
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: Algebraic Geometry (math.AG)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper we analyze the heat kernel of the equation $\partial_tv =\pm\mathcal{L} v$, where $\mathcal{L}=\partial_x^N+u_{N-2}(x)\partial_x^{N-2}+\cdots+u_0(x)$ is an $N$-th order differential operator and the $\pm$ sign on the right-hand side is chosen appropriately. Using formal pseudo-differential operators, we derive an explicit formula for Hadamard's coefficients in the expansion of the heat kernel in terms of the resolvent of $\mathcal{L}$. Combining this formula with soliton techniques and Sato's Grassmannian, we establish different properties of Hadamard's coefficients and relate them to the Gelfand-Dickey hierarchy. In particular, using the correspondence between commutative rings of differential operators and algebraic curves due to Burchnall-Chaundy and Krichever, we prove that the heat kernel consists of finitely many terms if and only if the operator $\mathcal{L}$ belongs to a rank-one commutative ring of differential operators whose spectral curve is rational with only one cusp-like singular point, and the coefficients $u_j(x)$ vanish at $x=\infty$. We also characterize these operators $\mathcal{L}$ as the rational solutions of the Gelfand-Dickey hierarchy with coefficients $u_j $ vanishing at $x=\infty$, or as the rank-one solutions of the bispectral problem vanishing at $\infty$.
"Men like stage-players act variety of parts": Performing melancholic parts on the early modern stage
Creators: name: Collins, Stephanie
Publisher: name: University of Leicester
Year: 2021
Subjects: Uncategorized

description: This thesis articulates the importance and influence of medical understandings of humoural theory, particularly melancholy, on English drama of the late 1580s to the 1620s. Using a case study approach of early modern dramatic texts by playwrights such as Shakespeare, Marlowe, Kyd, Chapman, and Middleton, amongst others, alongside an examination of key pieces of medical and religious writing, this thesis investigates the interrelationship between medicine and the theatre which occurred throughout the late sixteenth and early seventeenth centuries to question why dramatists were so concerned with the medicalisation of drama, and the dramatization of medicine.This thesis applies Judith Butler’s concept of anatomical sex, gender identity, and gender performance to the experience of emotion. Building on research by Gowland, Lund, and Langley, the study identifies melancholy as a performative emotion, both in that it is often performed and that its symptoms lend themselves to spectacle. This leads us to discuss both the performances of “anatomical” emotion, and the idea that emotion is something which can be performed, convincingly or otherwise.Taking its cue from Burton’s The Anatomy of Melancholy (1621), this thesis identifies three types of melancholy which were most regularly being presented on the early modern stage: scholarly melancholy, revenger’s melancholy, and love melancholy. This thesis looks at the ways the representations of these melancholic types often overlap, how one melancholy could lead to or be influenced by another kind, and the connotations and significance of these interrelationships. Chapter One begins by looking at the portrayal of scholarly melancholy, and how it can be used alongside love melancholy and religious melancholy, focusing on Doctor Faustus (1589-1592), Love’s Labour’s Lost (1595), and Hamlet (1599). Chapter Two’s focus on the revenge tragedies of the late 1500s – early 1600s also sees an interest in Hamlet, alongside works by Kyd and Middleton to highlight the way melancholy began to be portrayed specifically as a performative emotion, with links to excessive theatricality. Chapter Three’s focus shifts towards comedy and the different ways in which melancholy could be used in comedy – both as something to laugh at, and as something which could derail the traditional comic ending in texts such as The Merchant of Venice, Monsieur D’Olive, and Every Man in His Humour. Chapter Four moves forward to the work of John Ford in the 1620s and highlights the relationship between Ford and Burton which we see in The Lover’s Melancholy, ’Tis Pity She’s a Whore, and The Broken Heart. Returning to the tragedies, Chapter Four suggests that the work of Ford represents a culmination of the melancholic discourses which have come before, as scholarly melancholy, vengeful melancholy, love melancholy, and even comic melancholy combine in what could be considered medical drama.
Spectroscopy of Quasar Candidates from SDSS Commissioning Data
Creators: name: Fan, Xiaohui
name: Strauss, Michael A.
name: Annis, James
name: Gunn, James E.
name: Hennessy, Gregory S.
name: Ivezic, Zeljko
name: Knapp, Gillian R.
name: Lupton, Robert H.
name: Munn, Jeffrey A.
name: Newberg, Heidi J.
name: Schneider, Donald P.
name: Yanny, Brian
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The Sloan Digital Sky Survey has obtained images in five broad-band colors for several hundred square degrees. We present color-color diagrams for stellar objects, and demonstrate that quasars are easily distinguished from stars by their distinctive colors. Follow-up spectroscopy in less than ten nights of telescope time has yielded 22 new quasars, 9 of them at $z> 3.65$, and one with $z = 4.75$, the second highest-redshift quasar yet known. Roughly 80% of the high-redshift quasar candidates selected by color indeed turn out to be high-redshift quasars.
description: 4 pages, 3 figures, to appear in the proceedings of "After the Dark Ages: When Galaxies were Young (the Universe at 2
GPU-accelerated high-order scale-resolving simulations using the flux reconstruction approach
Creators: name: Ntemos, George
Publisher: name: Imperial College London
Year: 2017

description: High-order methods in Computational Fluid Dynamics (CFD) offer a potential route towards the resolution of hitherto intractable fluid-dynamics problems in industry. The Flux Reconstruction (FR) approach provides a unifying framework for a number of popular high-order methods such as the Discontinuous Galerkin (DG). Its suitability for use on unstructured grids along with its ability to facilitate massively parallelised implementation on architectures such as GPUs provide a means to tackle computationally challenging flows around complex geometries. Such a flow can be found in the rod-aerofoil tandem configuration: Complex, unsteady flow structures generated by and interacting with more than a single solid body are central to a number of applications in the aerospace industry. The current thesis attempts to demonstrate the suitability of the FR approach in successfully simulating the flow around a rod-aerofoil configuration. The in-house CFD solver employed in the research is presented and the FR implementation analysed. Computational grid resolution issues arising from the rod-aerofoil problem are studied and a novel strategy for the stabilisation of the computation is implemented in the form of local entropy stability. The results obtained are analysed and conclusions are drawn on the utility of the FR approach in the absence of a sub-grid scale model (Implicit LES - under-resolved DNS). The present work confirms the utility of local entropy stability for the stabilisation of the rod-aerofoil simulation of aerofoil-chord based Reynolds number of Re=480, 000. It will also demonstrate that the under-resolved DNS setup that resulted in a computational cost of approximately six hours for a single flow pass over the aerofoil chord on 200 Nvidia P100 GPUs resulted in moderate success for a significant portion of the flow dynamics, which not adequately predicted when compared with experiment. The latter led to a series of useful conclusions. The core of the conclusions involved the apparent over-prediction of time-averaged velocity and momentum deficits across wakes and as well as over-prediction of turbulent intensities. An identification of the problematic areas is therefore given and potential alleviation techniques outlined.
High capacitance silicon nanowire array electrodes
Creators: name: Shougee, Abdurrahman
Publisher: name: Imperial College London
Year: 2017

description: The interest in the development of improved, alternative and application-specific electrical energy storage solutions presents the opportunity for Si-based device with the functionality of electrochemical capacitors (ECs). Metal-assisted chemical etching (MACE) provides a low temperature and low-cost method of obtaining a high-density array of high aspect ratio silicon nanowires. The high surface area of the silicon nanowire arrays (SiNWA) is utilised to develop a high capacitance electrode, in conjunction with an ionic liquid (IL) electrolyte giving low volatility, high thermal stability, and high chemical stability enabling a higher operating voltage. High silicon reactivity necessitates passivation of the Si surface. A low temperature (120 °C) wet oxidation process provides a highly dense, ultra-thin (~1.4 nm) protective layer that extends the operating voltage and yields a high energy and power density, bringing the SiNWA electrode within the range of ECs. An alternative coating of metal oxide (TiO2) provides further performance improvement, and with energy and power densities of 0.9 and Wh·kg-1 and 2228 W·kg-1 respectively, places the developed SiNWA electrode towards the frontier of EC devices, as per the Ragone plot. Intermittent presence of apparent faradaic peaks observable on the cyclic voltammetry (CV) plots of SiNWA electrodes was analysed and attributed to the presence of deep level traps (DLTs) as a result of residual Ag from the MACE process. Multiple post-etch doping steps to degenerately dope the surface – pinning the Fermi level below the Si valence band – were found to mitigate the effect of the DLTs, improving the capacitive character and cycling stability of the electrodes.
Dynamic loading of periosteum-derived mesenchymal stromal cells
Creators: name: Sory, David Roger Raymond
Publisher: name: Imperial College London
Year: 2017

description: Explosive-generated waves exhibit high-energy loading profiles featured with mechanical characteristics applied over a wide range of strain rates. Recent decades have seen unprecedented occurrence of high-energy trauma associated with blast wave exposure. One such blast-specific pathology is blast-induced heterotopic ossification (bHO), which refers to ectopic bone formation due to inappropriate mesenchymal stromal cell (MSC) osteogenesis in non-skeletal tissues. Significant effort has been made into deciphering the molecular mechanisms that allow the onset of bHO, however little research has been reported on the exact role of the biomechanical processes involved in transducing blast-associated mechanical stimuli into molecular events stimulating osteogenesis in MSCs. The research presented in this thesis investigated the stimulation of osteogenesis in periosteum-derived mesenchymal stromal cells (PO MSCs) in response to mechanical insults simulating blast landmine trauma. This involved the development of experimental biocompatible in vitro platforms and the tailoring of biomechanically-relevant stimuli of varying stress intensities (up to 70 MPa), and strain rates (0.01 to 3000 /s). Subsequently, cell health and the stimulation of osteogenesis were investigated by studying the expression of Runx2 and Osteocalcin (OC) genes. We found that cell health was not affected by single-pulse loadings of wide range of impulse levels (0.20 to 95000 N.s). We showed evidence of mechanically-stimulated osteogenesis in PO MSCs through the upregulation of Runx2 and OC genes in loaded samples. Furthermore, our results highlighted that the stimulation of osteogenesis in MSCs did not result solely from the effect a single mechanical parameter, but rather the combined action of several features. We showed that osteogenesis stimulation in MSCs arised from the complex interplay between the mechanical characteristics of the loading along with the environment used to convey the stress wave. Finally, our research indicated that PO MSCs are finely tuned to respond to mechanical stimuli that fall within defined parameters.
Bose-Einstein condensation of photons
Creators: name: Marelic, Jakov
Publisher: name: Imperial College London
Year: 2017

description: A Bose-Einstein condensate can be made of photons. The photons are held at thermodynamic equilibrium in a dye-filled microcavity and pumped with a laser. Thermalisation can be demonstrated and above the threshold a Bose-Einstein condensate will form. A Mach-Zehnder interferometer is built and used to measure the spatial and temporal first-order coherence under various conditions. We build a momentum-resolved spectrometer and use it to obtain views into the phase-space distribution of the photon condensate. We put an upper bound on the value of the interaction strength parameter and find that the microcavity system is ergodic even when not at thermal equilibrium. We build a setup to stabilise the pump laser power with the aim to observe the λ-point of the condensate.
Topics in the probabilistic solution of ordinary differential equations
Creators: name: Teymur, Onur
Publisher: name: Imperial College London
Year: 2018

description: This thesis concerns several new developments in the probabilistic solution of ordinary differential equations. Probabilistic numerical methods are differentiated from their classical counterparts through the key property of returning a probability measure as output, rather than simply a point value. When properly calibrated, this measure can then be taken to probabilistically represent the output uncertainty arising from the application of the numerical procedure. After giving some introductory context, we start with a concise survey of the still-developing field of probabilistic ODE solvers, highlighting how several different paradigms have developed somewhat in parallel. One of these, established by Conrad et al. (2016), defines randomised one-step solvers for initial value problems, where the outputs are empirical measures arising from Monte Carlo repetitions of the algorithm. We extend this to multistep solvers of Adams-Bashforth type using a novel Gaussian process construction. The properties of this method are explored and its convergence is rigorously proved. We continue by defining a class of implicit probabilistic ODE solvers, the first in the literature. Unlike explicit methods, these modified Adams-Moulton algorithms incorporate information from the ODE dynamics beyond the current time-point, and as such are able to enhance the accuracy of the probabilistic model of numerical error. In their full form, they output a non-parametric description of the stepwise error, though we also propose a parametric approximation that aids computation. Once again, we explore the properties of the method and prove its convergence in the small step-size limit. We follow with a discussion on the problem of calibration for these classes of algorithms, and generalise a proposal from Conrad et al. in order to implement it for our methods. We then apply the new integrators to two test differential equation models, first in the solution of the forward model, then later in the setting of a Bayesian inverse problem. We contrast the effect of using probabilistic integrators instead of classical ones on posterior inference over the model parameters, as well as derived functions of the forward solution. We conclude with a brief discussion on the advantages and shortcomings of the proposed methods, and posit several suggestions for potential future research.
Dynamics of blue compact galaxies, as revealed by their H-alpha velocity fields I. The data, velocity fields and rotation curves
Creators: name: Östlin, G.
name: Amram, P.
name: Masegosa, J.
name: Bergvall, N.
name: Boulesteix, J.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Observations of six luminous blue compact galaxies (BCGs) and two star forming companion galaxies were carried out with the CIGALE scanning Fabry-Perot interferometer attached to the ESO 3.6m telescope on La Silla. The observations were made in the H-alpha emission line which is prominent in BCGs. A velocity sampling of 5 km/s and a pixel size of 0.9 arcseconds were used. In this paper we present the observations and the data together with the velocity fields and the derived rotation curves. In addition we provide rough estimates of the total dynamical mass and of the ionised gas mass for each galaxy. All galaxies display rotation, but while the companion galaxies have regular velocity fields, those of the BCGs are complex and appear perturbed. This is the most extensive study to date of the optical velocity fields of BCGs. The interpretation of these results will be presented in a forthcoming paper (Paper II).
description: 26 pages, 14 figures. Accepted for publication in A&AS. The paper (with figures in slightly higher resolution) and an electronic table is also available at ftp://ftp.iap.fr/pub/from_users/ostlin/Articles/ . Replaced version, figure captions fixed
Towards an accurate and transferable charge transfer model in polarisable interatomic potentials
Creators: name: Nemytov, Vadim
Publisher: name: Imperial College London
Year: 2018

description: Understanding the properties of defects, interfaces and other heterogeneities in metal oxides is crucial for enabling new applications. Some properties can be explored in a computer simulation using classical interatomic potentials (IPs) – analytic functions of nuclear positions that provide interatomic forces. In this thesis I have focused on developing, testing and analysing an ionic IP which combines variable-charge (QEq) and polarisable-ion (PI) models, allowing ions’ charges and induced dipole moments to vary in response to their changing environments. We aim to improve the limited transferability to heterogeneous environments of the current state-of-the-art, PI-based, IPs. For several bulk and heterogeneous systems, past applications of QEq-based IPs showed no improvement over fixed-charge IPs – at variance with common expectations. Two reasons for this have been suggested in our work – in some systems ionic charges are essentially-constant, in other systems the bonding doesn’t adhere well to the limit of the QEq model. Using density functional theory and the QEq-PI IP we calculated and analysed the charge distributions and interatomic forces in BaTiO3 at finite temperature, in a pristine crystal and near neutral O (VO) and Ti (VTi) vacancies. Ionic charges were found to be essentially-constant in the defect-free BaTiO3, but to deviate from their bulk values near the vacancies. The improvement of QEq-PI IP over fixed-charge IP was greater for the system with VO than with VTi, which was explained by the bonding near VO adhering better to the limit of this model. For systems with VO the QEq-PI IP demonstrated a marked improvement in accuracy and transferability over the fixed-charge PI IP; this is the first time, to our knowledge, that a clear improvement over PI IPs has been demonstrated.
Modeling and inference for counts time series based on zero-inflated exponential family INGARCH models
Creators: name: Lee, Sangyeol
name: Kim, Dongwon
name: Seok, Seongwoo
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Medicine
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics

description: This study considers statistical inferences such as parameter estimation and change tests for counts time series models where the conditional density of present observations over past information follow a zero-inflated one-parameter exponential family. We verify that the zero-inflated exponential family (ZIEF) INGARCH process is stationary and ergoic, and the maximum likelihood estimator is consistent and asymptotically normal. We then construct CUSUM tests based on (standardized) residuals and squares of (standardized) residuals as a parameter change test. Their null distributions is shown to converge to the sup of a Brownian bridge in distribution. The validity of the CUSUM tests is confirmed through a simulation study and real data analysis.
Dissipative Process as a Mechanism of Differentiating Internal Structures between Dwarf and Normal Elliptical Galaxies in a CDM Universe
Creators: name: Mori, Masao
name: Yoshii, Yuzuru
name: Nomoto, Ken'ichi
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We simulate the dynamical, chemical, and spectro-photometric evolution of dwarf and normal elliptical galaxies embedded in a dark matter halo, using a three-dimensional N-body/SPH simulation code. For the forming dwarf elliptical galaxies, supernova-driven winds propagating outwards from inside the system collide with the infalling gas and produce the super-shell in which stars are formed. The resulting stellar system forms a loosely bound virialized system due to the significant mass loss and has a large velocity dispersion and a large core. Consequently the surface brightness distribution shows an exponential profile and the color distribution shows a positive gradient such that the colors become redder away from the galaxy center in agreement with observations. On the other hand, for the normal elliptical galaxies with deep gravitational potential, the mass loss out of the system does not have a significant dynamical effect on the stellar system. The resulting surface brightness distribution has a large central concentration like de Vaucouleurs' $r^{1/4}$-profile and the color distribution shows a negative gradient as observed. Our simulation shows that different features between dwarf and normal elliptical galaxies stem from different cooling efficiencies for their respective protogalaxies in a standard CDM universe.
description: 15 pages, 12 figures, to appear in the ApJ, issue of February 1, 1999
A new, nearly complete skull of Procolophon trigoniceps Owen, 1876 from the Sanga do Cabral Supersequence, Lower Triassic of Southern Brazil, with phylogenetic remarks
Creators: name: Silva-Neves, Eduardo
name: Modesto, Sean Patrick
name: Dias-Da-Silva, Sérgio
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Cell Biology
subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: 69999 Biological Sciences not elsewhere classified
subject: Plant Biology

description: The Sanga do Cabral Supersequence comprises the Sanga do Cabral and the Buena Vista formations from Brazil and Uruguay respectivelly. The Brazilian unit yields an abundant record of the procolophonid Procolophon trigoniceps, a biostratigraphic marker for the Lower Triassic, which allows correlation with the Katberg Formation, South Africa. P. trigoniceps, has a wide territorial extension, so this is one of the most successful groups after the greatest extinction event, the Permo-Triassic Extinction. We describe a new skull ascribed to Procolophon trigoniceps, which so far represents the most complete and best preserved specimen collected at the Lower Triassic Sanga do Cabral Supersequence, Southern Brazil, and assess its phylogenetic relationships. We also use CT scan techniques to assess hidden structures covered by a hard layer of rock matrix as a non-invasive method, which allowed the visualization of the palatal dentition of this new specimen. The actual diversity of procolophonians at the Sanga do Cabral Supersequence is still unknown because most specimens are fragmentary and poorly preserved, so this new, nearly complete skull fills an important gap in the knowledge of South American P. trigoniceps, given that previously described specimens of this taxon from this region of Gondwana are quite incomplete in comparison.
Explosive particle creation by instantaneous change of boundary condition
Creators: name: Miyamoto, Umpei
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the dynamic Casimir effect (DCE) of a $1+1$ dimensional free massless scalar field in a finite or semi-infinite cavity for which the boundary condition (BC) instantaneously changes from the Neumann to Dirichlet BC or reversely. While this setup is motivated by the gravitational phenomena such as the formation of strong naked singularities or wormholes, and the topology change of spacetimes or strings in quantum gravity, the analysis is quite general. For the Neumann-to-Dirichlet cases, we find two components of diverging flux emanate from the point where the BC changes. We carefully compare this result with that of Ishibashi and Hosoya (2002) obtained in the context of a quantum version of cosmic censorship hypothesis, and show that one of the diverging components was overlooked by them and is actually non-renormalizable, suggesting to bring non-negligible backreaction or semiclassical instability. On the other hand, for the Dirichlet-to-Neumann cases, we reveal for the first time that only one component of diverging flux emanates, which is the same kind as that overlooked in the Neumann-to-Dirichlet cases. This result suggests not only the robustness of the appearance of diverging flux in instantaneous limits of DCE but also that the type of divergence sensitively depends on the combination of initial and final BCs.
description: v1: 32 pages, 7 figures; v2: 35 pages, 7 figures, Abstract, Introduction, and References substantially revised, to appear in PRD
On the effective version of Serre's open image theorem
Creators: name: Mayle, Jacob
name: Wang, Tian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11G05 (Primary) 11F80 (Secondary)

description: Let $E/\mathbb{Q}$ be an elliptic curve without complex multiplication. By Serre's open image theorem, the mod $\ell$ Galois representation $\overlineρ_{E, \ell}$ of $E$ is surjective for each prime number $\ell$ that is sufficiently large. Under the generalized Riemann hypothesis, we give an explicit upper bound on the largest prime $\ell$, linear in the logarithm of the conductor of $E$, such that $\overlineρ_{E, \ell}$ is nonsurjective.
Dynamical Evolution and Ionization Structure of an Expanding Superbubble: Application to W4
Creators: name: Basu, Shantanu
name: Johnstone, Doug
name: Martin, P. G.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent observations have revealed a superbubble associated with the young stellar cluster OCl 352 near the W4 H II region: a void in H I emission (Normandeau, Taylor, and Dewdney), and a bright shell in H alpha emission (Dennison, Topasna, and Simonetti). We investigate the hypothesis that the bubble is blown by stellar winds from the O-type stars in the association. The Kompaneets approximation is adapted to model a wind-blown bubble in a stratified interstellar medium. We describe some general principles necessary for understanding the dynamics of an expanding bubble and the associated ionization structure in a stratified atmosphere. The Kompaneets model can be used to determine the mean scale height of the ambient medium as well as the age of the bubble. The ionization structure also places constraints on the ambient density near the cluster. We also estimate the surface brightness of the shell and the fraction of ionizing photons which escape the bubble. The prescription we use can be applied to any observed bubble that is blown by the effectively continuous energy output of stellar winds or multiple supernovae. Application to the W4 superbubble shows that the mean scale height of the ambient gas around the cluster is remarkably small, 25 pc for a cluster distance of 2.35 kpc. The age of the bubble is estimated to be about 2.5 Myr, consistent with the notion that the bubble is blown by stellar winds from a very young cluster in which no supernovae have yet occurred.
description: 36 pages, 12 figures, AASTeX, to appear in the Astrophysical Journal
Magneto-centrifugally driven winds: comparison of MHD simulations with theory
Creators: name: Ustyugova, G. V.
name: Koldoba, A. V.
name: Romanova, M. M.
name: Chechetkin, V. M.
name: Lovelace, R. V. E.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Stationary magnetohydrodynamic (MHD) outflows from a rotating, conducting Keplerian accretion disk threaded by B-field are investigated numerically by time-dependent, axisymmetric (2.5D) simulations using a Godunov-type code. A large class of stationary magneto-centrifugally driven winds are found where matter is accelerated from a thermal speed at the disk to much larger velocity, greater than the fast magnetosonic speed and larger than the escape speed. The flows are approximately spherical outflows with only small collimation within the simulation region. Numerical results are shown to coincide with the theoretical predictions of ideal, axisymmetric MHD to high accuracy. Investigation of the influence of outer boundary conditions, particularly that on the toroidal component of magnetic field shows that the commonly used ``free'' boundary condition leads to artificial magnetic forces which can act to give spurious collimation. New boundary conditions are proposed which do not generate artificial forces. Artificial results may also arise for cases where the Mach cones on the outer boundaries are partially directed into the simulation region.
description: 19 pages, 18 figures, emulapj.sty is used
Exploring protein dynamics using graph theory and single-molecule spectroscopy
Creators: name: Peach, Robert
Publisher: name: Imperial College London
Year: 2017

description: Proteins are the workhorses of any living system. They are essential for day-to-day life and yet we still do not fully understand how they work. Proteins are intricate structures composed of thousands of atoms that interact and fluctuate over multiple temporal and spatial scales. These motions are encoded in the peptide sequence; fast and local vibrations develop collectively into the motion of secondary structures and catalytic domains. Despite the importance of dynamical fluctuations in mediating function and other biomolecular processes such as allostery, there is inadequate evidence supporting the various theories and calculational approaches which attempt to determine the relationships between structure, dynamics and function. Graph theory provides a way of capturing and representing the 3-dimensional atomistic physico- chemical details of a protein in a reduced form. In this thesis, we use Markov Stability, a novel graph-theoretic method for analysing the hierarchy of protein motions. We begin by producing an energy-weighted atomistic graph representation of a protein. We then use the transient behaviour of a random-walk to identify regions of atoms/residues that form communities. Using mutagenesis we are able to identify mutations that result in a large change to the community structure. We then use experimental methods (primarily single-molecule FRET) to explore the effect of these predicted mutations and validate the predictive qualities of Markov Stability. In this thesis, we demonstrate a strong correlation between theoretical and experimental mea- sures. We focus our study on Adenylate Kinase; a protein that balances molecular stability and fast large domain motions in the pursuit of cellular energy homeostasis. Given the structural data taken from the protein data bank we use the Markov stability graph theoretical approach to identify a number of biologically relevant community structures at different timescales. We are able to illustrate agreement between Markov Stability and the rate of motions of ADK subdomains. We then use the graph theoretical analysis to predict the effect of mutations to global dynamics and validate these predictions using single-molecule FRET; we show excellent agreement between the calculated properties of the graph theoretical analysis and the variation in FRET dynamics. Finally, we explore the relationship between the predictive score attributed to mutants by Markov Stability and the associated change in molecular stability.
8-13 micron spectroscopy of NGC 253: a spatially resolved starburst
Creators: name: Dudley, C. C.
name: Wynn-Williams, C. G.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: NGC 253 is a nearby spiral galaxy that is currently undergoing a nuclear burst of star formation in a 100 pc diameter region. We present spatially resolved 8--13 micron low-resolution spectra at four positions along the ridge of 8--13 micron emission. We find that the relative strengths of the ionic, dust emission features, and dust continuum emission vary with position in the galaxy but can be accounted for everywhere without recourse to extinction by silicates. The brightest mid-infrared peak (which is displaced from the nucleus) has elevated levels of both continuum and 11.1--12.9 micron `plateau' emission, indicative of dust heated within a photo-dissociation region. Spectra obtained over the course of 3 yr at the position of the brightest mid-infrared peak show no significant time variation.
description: 8 pages, 3 figures, to appear in MNRAS
Research Data Management website to depth of 3 links at 2018.09.13
Creators: name: Burnham, Andrew
Publisher: name: University of Leicester
Year: 2018
Subjects: subject: 80706 Librarianship
subject: FOS: Media and communications
subject: 80707 Organisation of Information and Knowledge Resources

description: Research Data Management website at University of Leicester to depth of 3 links at 2018.09.13
Created as part of the JISCMRD Programme (2011-2013).