cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Additional file 1: of Onset and progression of diabetes in kidney transplant patients receiving everolimus or cyclosporine therapy: an analysis of two randomized, multicenter trials
Creators: name: Sommerer, Claudia
name: Witzke, Oliver
name: Lehner, Frank
name: Arns, Wolfgang
name: Reinke, Petra
name: Eisenberger, Ute
name: Vogt, Bruno
name: Heller, Katharina
name: Jacobi, Johannes
name: Guba, Markus
name: Stahl, Rolf
name: Hauser, Ingeborg
name: Kliem, Volker
name: WĂźthrich, Rudolf
name: MĂźhlfeld, Anja
name: Suwelack, Barbara
name: Duerr, Michael
name: Eva-Maria Paulus
name: Zeier, Martin
name: Porstner, Martina
name: Budde, Klemens
Publisher: name: figshare
Year: 2018
Subjects: subject: Space Science
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Sociology
subject: FOS: Sociology
subject: Immunology
subject: FOS: Clinical medicine
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Developmental Biology
subject: Marine Biology
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Science Policy
subject: 110309 Infectious Diseases
subject: FOS: Health sciences
subject: 60506 Virology
subject: Computational Biology

description: Table S1. Inclusion and exclusion criteria. Table S2. Efficacy endpoints between randomization and month 12 post-transplant in (a) the ZEUS study (b) the HERAKLES study. (DOCX 24 kb)
The Proton Distribution Function in Weakly Magnetized Turbulent Plasmas
Creators: name: Gruzinov, Andrei
name: Quataert, Eliot
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We calculate the proton distribution function due to heating by subsonic (Alfvenic) turbulence in a weakly magnetized collisionless plasma. The distribution function is nonthermal. For non-relativistic energies, it is an exponential of the magnitude of the proton velocity. For ultra-relativistic energies, it can be characterized as a power law with a momentum-dependent slope.
description: 7 pages, submitted to ApJ
Security-proof framework for two-way Gaussian quantum-key-distribution protocols
Creators: name: Zhuang, Quntao
name: Zhang, Zheshen
name: Lütkenhaus, Norbert
name: Shapiro, Jeffrey H.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Two-way Gaussian protocols have the potential to increase quantum key distribution (QKD) protocols' secret-key rates by orders of magnitudes~[Phys.~Rev.~A {\bf 94}, 012322 (2016)]. Security proofs for two-way protocols, however, are underdeveloped at present. In this paper, we establish a security proof framework for the general coherent attack on two-way Gaussian protocols in the asymptotic regime. We first prove that coherent-attack security can be reduced to collective-attack security for all two-way QKD protocols. Next, we identify two different constraints that each provide intrusion parameters which bound an eavesdropper's coherent-attack information gain for any two-way Gaussian QKD protocol. Finally, we apply our results to two such protocols.
description: 21 pates, 8 figures
Assessing the efficiency of thermal pressurisation using natural pseudotachylyte-bearing rocks
Creators: name: Brantut, Nicolas
name: Mitchell, Thomas M.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: The efficiency of thermal pressurisation as a dynamic weakening mechanism relies on the thermal and hydraulic properties of the rocks forming the fault core. Here, we assess the effectiveness of thermal pressurisation by comparing predictions of temperature rise to field estimates based on pseudotachylyte-bearing rocks. We measure hydraulic and transport properties of a suite of fault rocks (a healed cataclasite, an unhealed breccia and the intact parent rock) from the pseudotachylyte-bearing Gole Larghe fault in the Adamello batholith (Italy), and use them as inputs in numerical simulations of thermal pressurisation. We find that the melting temperature can be reached only if damaged, unhealed rock properties are used. A tenfold increase in permeability, or a fourfold increase in pore compressibility of the intact rock is required to achieve melting. Our results emphasise the importance of damage processes that strongly modify fault rock properties and dynamic weakening processes during earthquake propagation.
description: 7 pages, 4 figures, 1 table
Inelastic electron tunnelling spectroscopy using nanoscale tunnel junctions
Creators: name: Hamidizadeh, Yasaman
Publisher: name: Imperial College London
Year: 2014

description: Inelastic Electron Tunnelling Spectroscopy (IETS) [1-5] provides a means to characterise the phonon spectrum of a molecule by measuring the phonon-assisted tunnelling current through a potential barrier impregnated with target molecules. Traditionally, this technique has used Metal - Insulator - Metal (MIM) junctions, and the molecules of interest are adsorbed on to the insulator during junction fabrication. At low applied voltage V, tunnelling through the barrier is elastic. However, inelastic tunnelling caused by electron interaction with vibrational states in the adsorbed molecules can create additional conduction channels, occurring when V reaches a value of ħω/e, where ω is a molecular vibrational mode. These lead to peaks in the d^2 I / dV^2 vs. V characteristics for each additional channel, giving a spectrum of the molecular vibration modes. As energy separations in the vibrational spectrum are relatively small compared to the electronic spectrum, the full vibrational spectrum is measured only at T < 30K. However, it may be possible to measure part of the spectrum even at room temperature, raising the possibility of a molecular detector. This project is concerned with fabricating nanoscale tunnel junctions based on Si nanowires (NWs) made by electron-beam lithography (EBL), for the purpose of IETS measurements, at 300K. A Si / SiO2 tunnel barrier / Al structure is used, where the Al NW crosses an oxidised Si NW. This allows the fabrication of tunnel junctions down to 50nm x 120nm in area and tunnelling occurs across a 10nm thick SiO2 layer. The reduction in device dimensions to the nanoscale may increase the sensitivity of the device to molecules adsorbed on the tunnel junction. Furthermore, the use of Silicon on insulator (SOI) material allows modulation of the tunnel junction using the back gate formed by the SOI substrate, control the Fermi energy and electron concentration in the NW, and hence the IETS characteristics of the device. In principle, an IETS sensor may be possible using such a configuration. In principle, a switchable IETS measurements are performed at 300K for ammonium hydroxide (NH4OH), acetic acid (CH3COOH), and propionic acid (C3H6O2) molecules. The I-V , dI/dV - V , and d2^I/dV^2-V characteristics of the tunnel junction are measured before and after the adsorption of molecules on the junction using vapour treatment or immersion. Peaks can be observed in the d^2I/dV^2-V characteristics in all the cases following molecules adsorption. These peaks may be attributed to vibrational modes of N-H and C-H bonds. Simulation of IETS characteristics modelled based on a combination of elastic, inelastic tunnelling and Schottky barriers at the Si / SiO2 / Al interface in the device. A comparison has been made between the simulation results and experimental measurements which showed very good agreement. This device modelling can be used to predict experimental characteristics and allow thermal broadening of the IETS peaks to be investigated.
LipoFlash: A nanoparticle composed of bacterial lipoprotein LipoMetQ and Rose Bengal for photodynamic therapy
Creators: name: Arslanian, Marc
name: Sharaf, Naima
Publisher: name: Stanford Digital Repository
Year: 2026
Subjects: subject: Bacterial lipoproteins
subject: Rose Bengal
subject: Encapsulation efficiency
subject: Escherichia coli

description: A major downside of common cancer therapies, such as chemotherapy, is their non-selective nature, which results in patients experiencing various negative symptoms, including nausea, hair loss, and fatigue. Nanotechnology-based drug delivery systems, such as liposomes and human apolipoproteins, can selectively deliver small-molecule therapeutics to target sites; however, the potential of bacterial lipoproteins as drug carriers remains largely unexplored. Bacterial lipoproteins offer a promising alternative due to their lower-cost formulation compared to other nanotechnologies. This study aims to determine the encapsulation efficiency of bacterial lipoproteins using Rose Bengal (RB), a fluorescent dye used in photodynamic therapy, as a model drug. Bacterial lipoproteins from Neisseria meningitidis were expressed in Escherichia coli and tested to quantify encapsulation efficiency. This research addresses the gap in studying bacterial lipoproteins as targeted drug delivery platforms. By addressing this gap, this research highlights bacterial lipoproteins as a potential low-cost alternative for targeted drug delivery. Future work will focus on optimizing encapsulation efficiency and assessing the clinical applicability of bacterial lipoproteins.
On photohadronic processes in astrophysical environments
Creators: name: Muecke, A.
name: Rachen, J. P.
name: Engel, R.
name: Protheroe, R. J.
name: Stanev, T.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We discuss the first applications of our newly developed Monte Carlo event generator SOPHIA to multiparticle photoproduction of relativistic protons with thermal and power law radiation fields. The measured total cross section is reproduced in terms of excitation and decay of baryon resonances, direct pion production, diffractive scattering, and non-diffractive multiparticle production. Non--diffractive multiparticle production is described using a string fragmentation model. We demonstrate that the widely used `$Δ$--approximation' for the photoproduction cross section is reasonable only for a restricted set of astrophysical applications. The relevance of this result for cosmic ray propagation through the microwave background and hadronic models of active galactic nuclei and gamma-ray bursts is briefly discussed.
description: 9 pages including 4 embedded figures, submitted to PASA
Sciurus getulus Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Sciuridae
Sciurus
Sciurus getulus

description: Sciurus getulus [spec. nov.]
S. fuscus, striis quatuor albidis longitudinalibus.
Sciurus getulus. Raj. quadr. 216. Edv. av. 198. t. 198. Seb. mus. 1. p. 76. t. 47. f. 3.
Habitat in Africa.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 64, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Characterisation of monolithic tandem solar cells containing strain balanced quantum well sub-cells
Creators: name: Ioannides, Andreas
Publisher: name: Imperial College London
Year: 2015

description: This thesis presents the milestone efficiency of 30.6% under 54x concentration achieved by a monolithic tandem solar cell containing strain balanced quantum well sub-cells. This is the first demonstration of tandem cells containing quantum well sub-cells. Characterisation and modelling of the quantum efficiency and dark currents of monolithic tandem cells containing quantum well sub-cells are also presented for the first time. Predictions performed by a simulation program indicate that 32.3% efficiency at 500x concentration can be achieved and in combination with an active Ge substrate efficiencies of 37.5% are possible. The model created in the simulation program is presented which makes possible the accurate fitting of quantum efficiency and prediction of dark current. The procedure developed to process tandem solar cells into concentrator devices is presented. A detailed account of the characterisation methods used for tandem solar cells are also described. Going further, a new optical concept for building integrated PV design was examined in this thesis. The design is based on a Buffon lens as an alternative to convex and Fresnel lens designs. The low cost design presented can be accommodated in the space of a double glazing window for glass facades.
The effects of type 2 diabetes associated risk loci on pancreatic beta cell function
Creators: name: Mitchell, Ryan
Publisher: name: Imperial College London
Year: 2016

description: The pancreatic islets of Langerhans play a fundamental role in the stabilisation of blood glucose levels. Pancreatic islets are spherical structures composed of multiple cell types, with each individual cell type secreting a peptide hormone, such as insulin and glucagon, which regulates whole body glucose homoeostasis. Defective hormone secretion from islet cells is a hallmark of certain metabolic diseases, including type 2 diabetes mellitus (T2D). The most abundant islet cell type is the pancreatic β-cell, a specialised cell type that secretes the hypoglycaemic hormone insulin in response to raised glucose levels. Alterations in both β-cell mass and function are the causative factor for the development of T2D. Both genetic and environmental factors are known to underlie the decline in β-cell function typical of T2D. Specifically, genome wide association studies (GWAS) have identified over 100 genomic loci that are associated with T2D risk. Among these loci, variants that lie within/near ADCY5, SLC30A8 and PAX6 show associations with both T2D and abnormal glycaemic parameters typical of a diabetic phenotype. Therefore, the aims of this thesis were to understand how variants associated with T2D manifest at the level of the pancreatic islet. The expression of these genes was therefore manipulated through the generation of tissue-specific transgenic and knockout mice and by RNA interference in human tissue. Reducing the expression of ADCY5, encoding adenylate cyclase five, in human islet tissue reduced glucose-stimulated insulin secretion. This was accompanied by impairments in the metabolic and non-metabolic parameters that govern the secretory response of islets to glucose and other secretagogue. Deleting ZnT8, a β-cell zinc transporter and the gene product of the Slc30a8 gene, in the mouse β-cell significantly impaired the ability of these animals to mount effective responses to glucose. Interestingly, the reverse phenotype, i.e. improved glucose tolerance, was seen in animal models that overexpress ZnT8 in the β-cell. Finally, deletion of Pax6 in the adult mouse resulted in a drastic diabetic phenotype accompanied with changes in the cellular architecture of the islet and alterations in β-cell glucose signalling. Therefore, ADCY5, SLC30A8/ZnT8 and PAX6 gene variants likely negatively impact upon β-cell mass and function leading to a diabetic phenotype. Furthermore, these genes highlight distinct pathways, intrinsic to the pancreatic β-cell, which could be therapeutically targeted in the treatment of T2D.
A 3-mode, Variable Velocity Jet Model for HH 34
Creators: name: Raga, A.
name: Noriega-Crespo, A.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Variable ejection velocity jet models can qualitatively explain the appearance of successive working surfaces in Herbig-Haro (HH) jets. This paper presents an attempt to explore which features of the HH-34 jet can indeed be reproduced by such a model. From previously published data on this object, we find evidence for the existence of a 3-mode ejection velocity variability, and then explore the implications of such a variability. From simple, analytic considerations it is possible to show that the longer period modes produce a modulation on the shorter period modes, resulting in the formation of ``trains'' of multiple knots. The knots observed close to the source of HH-34 could correspond to such a structure. Finally, a numerical simulation with the ejection velocity variability deduced from the HH-34 data is computed. This numerical simulation shows a quite remarkable resemblance with the observed properties of the HH-34 jet.
description: 28 pages LaTex, 10 postscript figures
Time-scale and memory in financial time series: a data mining approach
Creators: name: Tzouras, Spilios
Publisher: name: Imperial College London
Year: 2015

description: Financial time series analysis is a highly empirical discipline concerned with the evolution of the price of an asset. The key feature that distinguishes financial time series from time series of other scientific domains is the element of uncertainty that they contain. The recent financial crisis has tested the capabilities of several existing models and evidenced the need for methods able to deal with the high complexity and the non-stationary characteristics of the data observed in financial markets. The objective of this thesis is to provide a better understanding of financial time series, to enhance the abilities of existing methods, especially their predictive performance but also to develop novel methods which aim to provide inferences in the presence of non-stationarities and reduce the complexity of high dimensional tasks. To this end, the memory in the magnitude and the memory in the sign of logarithmic returns is studied and a novel model is constructed whose fit suggests that long memory might be present in the volatility process and that when memory in the sign increases so does the memory in the magnitude. Additionally, wavelets are employed for that they operate in both the time and frequency domains. Thus, classic time series models and other methods extensively used in the time domain are deployed across different frequency bands to combine knowledge from both domains and provide information that might not be accessible otherwise. In particular, the volatility process is modeled in the time domain after some of the noisy behavior that exists in high frequencies, which might also contain outliers, is neglected. Moreover, the volatility process is modeled directly in the wavelet domain in a scale-by- scale manner in an effort to improve the forecasting performance. Furthermore, we attempt to detect changes in the autocorrelation function of a process, which result in changes in the spectral density function, by monitoring the wavelet variance across different multiresolution scales.
Sciurus striatus Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Sciuridae
Sciurus
Sciurus striatus

description: Sciurus striatus [spec. nov.]
S. flavus striis quatuor fuscis longitudinalibus. Mus. Ad. Fr. 8. *
Sciurus striatus. Catesb. car. 2. p. 75. t. 75. Edv. av. 181. t 181.
Roesselvissla. Kalm. itin. 2. p. 419.
Habitat in America septentrionali sub terra.
Magnitudine Muris musculi vel paulo major. Palmae tetradactylae, plantae pentadactylae.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 64, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Microvesicles as mediators of inflammation in severe burn injury
Creators: name: Porter, John Robert Stephen
Publisher: name: Imperial College London
Year: 2015

description: The host response to a severe burn injury is characterised by exaggerated systemic inflammation. Early clinical manifestations include shock, respiratory failure, renal failure and immunosuppression. The signalling pathways that propagate the inflammatory response are unclear but have traditionally been thought to involve overspill of proinflammatory cytokines. The importance of microvesicles, sub-cellular membrane-bound particles, is increasingly being recognised in the context of intercellular communication. Although circulating microvesicles are elevated in proinflammatory states such as sepsis, their relevance to the post-burn inflammatory response has not previously been evaluated. We hypothesised that circulating microvesicles play a crucial role in propagating the post-burn inflammatory response. Our overall aims were to 1) optimise protocols for the processing and analysis of plasma samples for microvesicle content; 2) characterise the circulating microvesicle profile associated with severe burn injury; 3) develop in vitro techniques to assess microvesicle production and function. The major findings of this work were that microvesicles derived from leukocytes, neutrophils, monocytes and endothelial cells were significantly elevated within 24 hours of burn injury. Microvesicle levels fell rapidly and were significantly decreased by day two post-injury. Total leukocyte- and neutrophil-derived microvesicles were significantly higher in non-survivors of burn injury as compared to survivors. In vitro studies demonstrated that neutrophil microvesicle release could be elicited by incubation with opsonised heat-killed cells. Pilot analysis of burn patient samples, using an endothelial co-culture assay, suggested that microvesicles may regulate the innate immune response to burn injury. These findings indicated that circulating microvesicles are an important component of the post-burn inflammatory response. Their precise activity is likely to be subtype-specific but the association of neutrophil-derived microvesicles with patient outcome alludes to a key role in burn pathophysiology.
Sciurus volans Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Sciuridae
Sciurus
Sciurus volans

description: Sciurus volans [spec. nov.]
S. hypochondriis prolixis volitans. Faun. suec. 22. Syst. nat. 9.
Sciurus volans. Seb. mus. 1. p. 67. t. 41. f. 3. Catesb. car. 2. p. 76. & 77. Edv. av. 191. t. 191.
Mus ponticus s. scythicus. Gesn. quadr. 743.
Quadrupes volatile russiae. Act. petr. 5. p. 218.
Habitat in borealibus Europae, Asiae, Americae.
Extensa cute inter brachia & femora volitat.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 64, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Additional file 1: of Iron deficiency during pregnancy is associated with a reduced risk of adverse birth outcomes in a malaria-endemic area in a longitudinal cohort study
Creators: name: Fowkes, Freya
name: Kerryn Moore
name: D. Opi
name: Simpson, Julie
name: Langham, Freya
name: Stanisic, Danielle
name: Ura, Alice
name: King, Christopher
name: Siba, Peter
name: Mueller, Ivo
name: Rogerson, Stephen
name: Beeson, James
Publisher: name: figshare
Year: 2018
Subjects: subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Biotechnology
subject: 69999 Biological Sciences not elsewhere classified
subject: 19999 Mathematical Sciences not elsewhere classified
subject: FOS: Mathematics
subject: Developmental Biology
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: Supplementary methods and analyses. (DOCX 142 kb)
Additional file 1: of Rapid dissemination of alpha-synuclein seeds through neural circuits in an in-vivo prion-like seeding experiment
Creators: name: Okuzumi, Ayami
name: Kurosawa, Masaru
name: Hatano, Taku
name: Takanashi, Masashi
name: Shuuko Nojiri
name: Fukuhara, Takeshi
name: Yamanaka, Tomoyuki
name: Miyazaki, Haruko
name: Yoshinaga, Saki
name: Furukawa, Yoshiaki
name: Shimogori, Tomomi
name: Hattori, Nobutaka
name: Nukina, Nobuyuki
Publisher: name: figshare
Year: 2018
Subjects: subject: Biophysics
subject: Space Science
subject: Medicine
subject: Molecular Biology
subject: Neuroscience
subject: Physiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: Developmental Biology

description: Rapid dissemination of alpha-synuclein seeds through neural circuits in an in-vivo prion-like seeding experiment. (PDF 1420 kb)
Photon isolation and jet substructure
Creators: name: Hall, Eleanor
name: Thaler, Jesse
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We introduce soft drop isolation, a new photon isolation criterion inspired by jet substructure techniques. Soft drop isolation is collinear safe and is equivalent to Frixione isolation at leading non-trivial order in the small R limit. However, soft drop isolation has the interesting feature of being democratic, meaning that photons can be treated equivalently to hadrons for initial jet clustering. Taking advantage of this democratic property, we define an isolated photon subjet: a photon that is not isolated from its parent jet but is isolated within its parent subjet after soft drop declustering. The kinematics of this isolated photon subjet can be used to expose the QED splitting function, in which a quark radiates a photon, and we verify this behavior using both a parton shower generator and a perturbative calculation in the collinear limit.
description: 23 pages, 6 figures; v2: minor changes to match journal version
Pecora Linnaeus, 1758, ord. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Pecora

description: Pecora [ord. nov.]
VI. PECORA.
Dentes Primores superiores nulli.
Inferiores VI aut VIII, a molaribus remotissimi.
Pedes ungulati.
Mammae inguinales.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 65, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Difference Frequency of Kilohertz QPOs Not Equal to Half the Burst Oscillation Frequency in 4U 1636-53
Creators: name: Mendez, Mariano
name: van der Klis, Michiel
name: van Paradijs, Jan
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have analyzed data obtained during two observations with the Rossi X-ray Timing Explorer on January 5 and 8, 1997, of the low-mass X-ray binary (LMXB) and atoll source 4U 1636-53. We measure the frequency separation of the two simultaneous kilohertz quasi-periodic oscillations (kHz QPOs) in this source to be 253.7 +/- 4.7 and 246.4 +/- 5.4 Hz, respectively. These values are inconsistent with being equal to 0.5 times the frequency of the 581-Hz oscillations that have been detected previously in 4U 1636-53 during type I bursts. The weighted average discrepancy is 39.5 +/- 3.5 Hz. This result shows that a simple beat-frequency interpretation of the kHz QPOs, in which the frequency of the oscillations detected during type I bursts equals the separation between the two kHz QPOs (or twice that value), is incorrect.
description: Accepted for publication in The Astrophysical Journal Letters. 4 pages plus 1 postscript figure
Microscopic modelling of boiling
Creators: name: Giustini, Giovanni
Publisher: name: Imperial College London
Year: 2016

description: One of the main thermal-hydraulic challenges of LWR modelling is the prediction of boiling phenomena. This thesis describes numerical and analytical studies aimed at modelling the heat transfer and hydrodynamics of a single steam bubble during nucleate boiling of water, aiming both to improve our current understanding of the phenomena - of the evaporation process itself, and of nucleate boiling heat transfer - and to improve our ability to predict such phenomena, at both single bubble and component scales. Analytical and CFD studies of bubble formation are described. These require accurate representations of evaporation from the liquid microlayer at the bubble base. This vaporization has been investigated from a molecular point of view, with modelling base on kinetic theory, and an apparent inconsistency in measurements of microlayer evaporation during bubble formation has been resolved, and an improved understanding of the molecular mechanism of phase-change thereby gained. The importance of including this improved representation of the evaporation process in single-bubble CFD simulations has been demonstrated. Aiming to improve the closure relations employed for component-scale CFD simulation of boiling flows, interface-tracking modelling of bubble growth and release has been used. Single-bubble interface-tracking models have been developed in an attempt to quantify the transient conduction (“quenching”) component of nucleate boiling heat transfer, associated with bubble lift-off. These mechanistic models allowed detailed quantification of the complex physics associated with bubble growth, and with quenching of the dry area at the bubble base that takes place at bubble departure. A large discrepancy was observed between estimates of the quench heat transfer from these interface-tracking simulations, and that incorporated in the more approximate modelling embodied in the closure relations widely used in component scale CFD.
Single quantum emitters: resonance fluorescence and emission enhancement
Creators: name: Grandi, Samuele
Publisher: name: Imperial College London
Year: 2017

description: Single photons are highly desirable for encoding, sending and processing quantum information. Suitable engineering of single quantum emitters and their environment can lead to a reliable single photon source and to mediated photon-photon interactions, essential assets for quantum communication and computation purposes. Dye molecules, our chosen single quantum emitter, have attracted much attention in recent years due to their high photostability and narrow emission lines. In this thesis I present a detailed analysis of the optical properties of single dibenzoterrylene molecules in an anthracene matrix. Single photon emission is demonstrated at room and cryogenic temperatures. In the latter case, an analysis of the second-order correlation function of the emission of a single molecule is studied at various temperatures. The data agree with a full solution of the optical Bloch equations over a wide range of temperature, and provide some insight into the dephasing process of the molecules. I then present a technique for integrating single dye molecules with nano-photonic devices. These are hybrid plasmonic waveguides, designed to guide light and to enhance the interaction with a single emitter by a tight confinement of the waveguide mode. Single molecules are deposited over the waveguides and a first evidence of coupling is presented. I conclude with proposed improvements to the optical setup and to the deposition methods. Finally, I present another type of integrated device, where the light matter interaction is enhanced by inserting single quantum emitters into coupled optical resonators. The theoretical description for the case of resonant two-photon absorption from single atoms in coupled photonic crystal cavities is developed. I conclude by proposing a possible realisation of this system, and describing the first steps towards the fabrication of such a device.
Analysis of a Hubble Space Telescope Search for Red Dwarfs: Limits on Baryonic Matter in the Galactic Halo
Creators: name: Graff, David S.
name: Freese, Katherine
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We re-examine a deep {\it Hubble Space Telescope} pencil-beam search for red dwarfs, stars just massive enough to burn Hydrogen. The authors of this search (Bahcall, Flynn, Gould \& Kirhakos 1994) found that red dwarfs make up less than 6\% of the galactic halo. First, we extrapolate this result to include brown dwarfs, stars not quite massive enough to burn hydrogen; we assume a $1/{\cal M}$ mass function. Then the total mass of red dwarfs and brown dwarfs is $\leq$18\% of the halo. This result is consistent with microlensing results assuming a popular halo model. However, using new stellar models and parallax observations of low mass, low metallicity stars, we obtain much tighter bounds on low mass stars. We find the halo red dwarf density to be $<1\%$ of the halo, while our best estimate of this value is 0.14-0.37\%. Thus our estimate of the halo mass density of red dwarfs drops to 16-40 times less than the reported result of Bahcall et al (1994). For a $1/{\cal M}$ mass function, this suggests a total density of red dwarfs and brown dwarfs of $\sim$0.25-0.67\% of the halo, \ie , $(0.9-2.5)\times 10^9\msun$ out to 50 kpc. Such a low result would conflict with microlensing estimates by the \macho\ group (Alcock \etal 1995a,b).
description: 13 pages, 2 figures. Figure one only available via fax or snail-mail To be published in ApJL. fig. 2 now available in postscript. Some minor changes in dealing with disk forground. Some cosmetic changes. Updated references
Abstraction, refinement and concurrent reasoning
Creators: name: Raad, Azalea
Publisher: name: Imperial College London
Year: 2016

description: This thesis explores the challenges in abstract library specification, library refinement and reasoning about fine-grained concurrent programs. For abstract library specification, this thesis applies structural separation logic (SSL) to formally specify the behaviour of several libraries in an abstract, local and compositional manner. This thesis further generalises the theory of SSL to allow for library specifications that are language-independent. Most notably, we specify a fragment of the Document Object Model (DOM) library. This result is compelling as it significantly improves upon existing DOM formalisms in that the specifications produced are local, compositional and language-independent. Concerning library refinement, this thesis explores two existing approaches to library refinement for separation logic, identifying their advantages and limitations in different settings. This thesis then introduces a hybrid approach to refinement, combining the strengths of both techniques for simple scalable library refinement. These ideas are then adapted to refinement for SSL by presenting a JavaScript implementation of the DOM fragment studied and establishing its correctness with respect to its specification using the hybrid refinement approach. As to concurrent reasoning, this thesis introduces concurrent local subjective logic (CoLoSL) for compositional reasoning about fine-grained concurrent programs. CoLoSL introduces subjective views, where each thread is verified with respect to a customised local view of the state, as well as the general composition and framing of interference relations, allowing for better proof reuse.
Optimal scheduling in sensor networks
Creators: name: Zhang, Luxin
Publisher: name: Imperial College London
Year: 2017

description: We aim to address, some of the fundamentals on how to model the optimal control of data problems arising in this big data era accurately and effectively. In this thesis, we have introduced a framework for formulating and solving the optimal scheduling problem of both communication and computation in a sensor network, with minimising the latency, i.e. the overall task completion time, and the total energy consumption as the objectives. We are able to schedule both the communication and computation by formulating the proposed optimal scheduling problem as a nonlinear programming (NLP) problem. We present two novel optimal scheduling problems in sensor networks: a single objective scheduling problem, minimising the overall task completion time, and a bi-objective scheduling problem, minimising both the overall task completion time and the total energy consumption. We propose the design of a decentralised discrete processing and transmission protocol, effectively turning the continuous-time, uncountable speed set solution into a discrete-time, countable speed set implementation. This significantly reduces the computation complexity compared to solving a mixed integer nonlinear programming (MINLP) instead. By implementing the normal constraint (NC) method, we are able to generate an evenly-distributed point-wise approximation of the Pareto curve to show the energy and latency trade-offs of our proposed bi-objective optimal scheduling problem. The Pareto curve can provide a guideline and reference for parameter design and selection. We also demonstrate how to modify and implement our framework by studying the optimal communication setup of smart meters in a smart building. The modified formulation and several case studies on optimal communication topology and transmission rates setups in various smart meter networks are presented. Numerical results show that the overall energy consumption can be reduced by implementing the optimal communication architecture and transmission rate setup, rather than implementing a straightforward communication architecture with uniform channel bandwidth.
The Most Completely Sampled Rotation Curves for Galaxies
Creators: name: Sofue, Yoshiaki
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have compiled high-resolution position-velocity diagrams observed along the major axes of nearby spiral galaxies in the CO-line emission, and derived rotation curves for the inner regions of the galaxies. We have combined the inner rotation curves with the outer HI and optical rotation curves to obtain the total rotation curves. The inner rotation curves are characterized by a steep increase within a few hundred pc radius, indicating a compact massive concentration near the nucleus. We fit the obtained rotation curves for individual galaxies by a modified Miyamoto-Nagai's potential by assuming existence of four mass components; a nuclear mass component with a scale radius of 100-150 pc and a mass of $\sim 3-5\times 10^{9}Msun$; a central bulge of 0.5 to 1 kpc radius of a mass $\sim 10^{10}Msun$; a disk with scale radius 5 to 7 kpc and thickness 0.5 kpc of a mass $\sim 1-2 Mgal$; and a massive halo of scale radius 15 to 20 kpc with a mass $\sim 2-3 Mgal$. We discuss the implication of the nuclear compact mass component for the formation mechanism of multiple structures within the galactic bulge during its formation.
description: Plain TEX, 16 pages, Figures on request, to appear in ApJ
Fundamental properties, disorder and stability of methylammonium lead halide perovskites for solar cells
Creators: name: Leguy, Aurélien
Publisher: name: Imperial College London
Year: 2016

description: Hybrid perovskite semiconductors from the MAPbX3 family (MA= CH3NH3; X = I, Br, Cl) can be used to make efficient (> 22 %) solar cells despite disorder introduced by solution processing. Much remains to be understood about these materials. Optical constants of MAPbX3 single crystals derived from ellipsometry measurements are assigned to inter-band transitions from electronic structure calculations. These are used to simulate the contributions from diﬀerent optical transitions to a typical transient absorption spectrum. The ellipsometry measurements are further used to show the reversible formation of CH3NH3PbI2·H2O and/or (CH3NH3)4PbI6·2H2O in single crystals thin films and devices upon exposure of MAPbI3 to water vapour, which is an important degradation pathway. Quasi-elastic neutron measurements allowed the dynamics of MA cations to be probed in the material. The dipolar MA+ reorientate between preferred alignments with a room temperature residence time of ~14 ps. Collective realignment of MA+ to screen a device’s built-in potential could reduce photovoltaic performance. However, the timescale for a domain wall to traverse a typical device is roughly estimated to be ~0.1 – 1 ms, faster than most observed hysteresis in MAPbI3 solar cells. Temperature dependent Raman and terahertz spectroscopy measurements indicate that MA+ reorientations are crucial to the transport properties of the material. Most of the vibrational features in MAPbX3 observed between 50 and 3500 cm-1 are assigned to calculated vibrational modes. The presence of additional peaks in the experimental spectra might be due to mode splitting caused by dynamic effects. The spectral linewidths of MAPbX3 indicate unusually short phonon lifetimes, linked to its low lattice thermal conductivity. This suggests that optical rather than acoustic phonon scattering prevails at room temperature in these materials, limiting charge mobility. These findings highlight the central role of disorder and heterogeneity to the optoelectronic properties of MAPbX3 and its impact on device behaviour and stability.
Radiative Efficiencies of Continuously Powered Blast Waves
Creators: name: Cohen, Ehud
name: Piran, Tsvi
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use general arguments to show that a continuously powered radiative blast wave can behave self similarly if the energy injection and radiation mechanisms are self similar. In that case, the power-law indices of the blast wave evolution are set by only one of the two constituent physical mechanisms. If the luminosity of the energy source drops fast enough, the radiation mechanisms set the power-law indices, otherwise, they are set by the behavior of the energy source itself. We obtain self similar solutions for the Newtonian and the ultra-relativistic limits. Both limits behave self similarly if we assume that the central source supplies energy in the form of a hot wind, and that the radiative mechanism is the semi-radiative mechanism of Cohen, Piran & Sari (1998). We calculate the instantaneous radiative efficiencies for both limits and find that a relativistic blast wave has a higher efficiency than a Newtonian one. The instantaneous radiative efficiency depends strongly on the hydrodynamics and cannot be approximated by an estimate of local microscopic radiative efficiencies, since a fraction of the injected energy is deposited in shocked matter. These solutions can be used to calculate Gamma Ray Bursts afterglows, for cases in which the energy is not supplied instantaneously.
description: 28 LaTeX pages, including 9 figures and 3 tables
Camelus Linnaeus, 1758, gen. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Artiodactyla
Camelidae
Camelus

description: Camelus [gen. nov.]
Cornua nulla.
Dentes Primores inferiores VI, spathiformes.
Laniarii distantes: superiores III, inferiores II.
Labium superius fissum.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 65, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Vortex-wave interactions and exact coherent structures in shear flows
Creators: name: Maestri, Joseph
Publisher: name: Imperial College London
Year: 2015

description: Recent studies of transition to turbulence in linearly stable shear flows have been dominated by finding, and characterising, so-called exact coherent structures which exist as either equilibrium or travelling wave solutions of the governing Navier-Stokes equations. These structures have been shown to act as either edge states between laminar and turbulent flow or become associated with attractors for turbulent flows, making the quest to understand these structures equally as mathematically interesting as it is industrially relevant. In this thesis, vortex-wave interaction theory, an asymptotic approach based on the assumption of large Reynolds number, is used as a means of finding such structures in plane Couette flow. A new, iterative, numerical method will be developed to solve the governing interaction equations that will allow us to circumvent many of the difficulties in calculating such structures (in particular at high Reynolds numbers) and perform analyses into the state-space of solutions, as well as explore their stability properties. A number of previously found exact coherent structures will be shown to be vortex-wave interaction states, including the so-called upper branch sinuous mode and the class of solutions called mirror-symmetric modes. A number of receptivity type problems will also be considered. Namely, the use of periodic blowing/suction on the channel walls and the introduction of variations in the wall shape. The effect of these two techniques on the skin friction drag and the wave amplitude will be discussed in the context of whether they are beneficial in terms of laminar flow control. Further, it will be shown that the use of periodic blowing/suction leads to a new class of synchronous mirror-symmetric modes and variations in the wall shape lead to a new class of inhomogeneous vortex-wave interaction states.
Transfer Learning from Speaker Verification to Multispeaker Text-To-Speech Synthesis
Creators: name: Jia, Ye
name: Zhang, Yu
name: Weiss, Ron J.
name: Wang, Quan
name: Shen, Jonathan
name: Ren, Fei
name: Chen, Zhifeng
name: Nguyen, Patrick
name: Pang, Ruoming
name: Moreno, Ignacio Lopez
name: Wu, Yonghui
Publisher: name: arXiv
Year: 2018
Subjects: subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We describe a neural network-based system for text-to-speech (TTS) synthesis that is able to generate speech audio in the voice of many different speakers, including those unseen during training. Our system consists of three independently trained components: (1) a speaker encoder network, trained on a speaker verification task using an independent dataset of noisy speech from thousands of speakers without transcripts, to generate a fixed-dimensional embedding vector from seconds of reference speech from a target speaker; (2) a sequence-to-sequence synthesis network based on Tacotron 2, which generates a mel spectrogram from text, conditioned on the speaker embedding; (3) an auto-regressive WaveNet-based vocoder that converts the mel spectrogram into a sequence of time domain waveform samples. We demonstrate that the proposed model is able to transfer the knowledge of speaker variability learned by the discriminatively-trained speaker encoder to the new task, and is able to synthesize natural speech from speakers that were not seen during training. We quantify the importance of training the speaker encoder on a large and diverse speaker set in order to obtain the best generalization performance. Finally, we show that randomly sampled speaker embeddings can be used to synthesize speech in the voice of novel speakers dissimilar from those used in training, indicating that the model has learned a high quality speaker representation.
description: NeurIPS 2018
Additional file 1: of Surveying knowledge, practice and attitudes towards intervention fidelity within trials of complex healthcare interventions
Creators: name: McGee, Daragh
name: Lorencatto, Fabiana
name: Matvienko-Sikar, Karen
name: Toomey, Elaine
Publisher: name: figshare
Year: 2018
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: Science Policy

description: Survey â â Surveying knowledge, practice and attitudes towards intervention fidelity within trials of complex healthcare interventionsâ . (PDF 136 kb)