cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Thermodynamics of Charged Defects in Ionic Crystals
Creators: name: Horton, Robert
Publisher: name: Imperial College London
Year: 2013

description: A generic methodology is developed in this thesis to calculate the thermodynamic contribution due to high concentrations of charged defects in ionic crystals. The aim of this methodology is to allow atomistic defect behaviour, such as correlation between defects, to be included in higher-level simulation techniques, for example, when calculating phase diagrams (using CALPHAD) or obtaining charge-concentration profiles through techniques such as solving the Poisson-Boltzmann equation. A number of Monte Carlo methods (specific-heat integration (SHI), Wang-Landau sampling (WL) and nested sampling (NS)) have been applied to a model of a simple solid-electrolyte system. This is an example of a system wherein defects in ionic crystals play a central role in the behaviour. The methods are then used to calculate the thermodynamic properties of the model; for example, it is shown that one can readily obtain the Helmholtz free energy. These properties can in turn be used to parameterise simple regular-solution approaches that allow the provision of a continuum-level description of the free energy. The thermodynamic description obtained from these Monte Carlo methods is compared to those given by more-traditional defect models, such as ideal-solution theory and Debye-Hückel theory, and it is shown that the thermodynamic behaviour of our model system agrees with such a description in the correct limits. The SHI, NS, and WL methods are compared in terms of computational efficiency and ease of implementation, and suggestions are made concerning the applicability of the methods in different regimes. Finally, some suggestions are made as to extensions and further applications of the work.
Additional file 1 of Antibiotic resistance in patients with clinical features of healthcare-associated infections in an urban tertiary hospital in Sierra Leone: a cross-sectional study
Creators: name: Lakoh, Sulaiman
name: Li, Letian
name: Sevalie, Stephen
name: Guo, Xuejun
name: Adekanmbi, Olukemi
name: Yang, Guang
name: Adebayo, Oladimeji
name: Yi, Le
name: Coker, Joshua
name: Wang, Shuchao
name: Wang, Tiecheng
name: Sun, Weiyang
name: Habib, Abdulrazaq
name: Klein, Eili
Publisher: name: figshare
Year: 2020
Subjects: subject: Space Science
subject: Medicine
subject: Biological Sciences not elsewhere classified
subject: Information Systems not elsewhere classified
subject: Mathematical Sciences not elsewhere classified
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Additional file 1. Antibiotic use among adult patients with clinical features of HAI.
The Optical Characterisation of Graphene
Creators: name: Xiao, Ye
Publisher: name: Imperial College London
Year: 2013

description: The discovery of graphene in 2004 [1] has prompted research into its potential in developing future electronic and photonic devices owing to its exceptional electronic and mechanical properties. Efforts to develop a scalable method of synthesis are ongoing and require a better understanding of the growth mechanisms of the various synthesis routes, as well as an examination of the properties of films produced by such methods. In this Thesis Raman spectroscopy is used to investigate graphene samples grown both by the reduction of graphite via graphene oxide as well as chemical vapour deposition on copper. In the case of the former, in-situ Raman spectroscopy was used to investigate the temporal evolution of graphene oxide exposed to different thermal treatments and under different reducing atmospheres. The study focused on the chemical processes which occur when graphene oxide is reduced by examination of the ID/G ratio which can be used to determine defect density by the Tuinstra-Koenig relationship [2]. The growth mechanism of graphene samples grown by chemical vapour deposition was also investigated. Here, the study focused on growth morphology by using simultaneous AFM-Raman mapping to characterise the strain and layer number profile, by analysis of the G and 2D peaks, of graphene samples grown on copper and relate them to the topography of the underlying substrate. The integration of graphene with plasmonic devices offers the potential for novel optoelectronic devices, which requires a better understanding of the optical response of graphene. Here, FTIR spectroscopy was used to probe the change in the resonance profile of a gold plasmonic nanoresonator array when encapsulated with a graphene overlayer. By comparison of the experimentally measured shift with simulated results using finite element modelling the photoconductivity of graphene was determined. The study also investigated the feasibility of graphene integrated plasmonic devices for chemical sensing applications.
Second main theorems for meromorphic mappings and moving hyperplanes with truncated counting functions
Creators: name: Quang, Si Duc
Publisher: name: arXiv
Year: 2018
Subjects: subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 32H30, 32A22, 30D35

description: In this article, we establish some new second main theorems for meromorphic mappings of $\mathbb C^m$ into $\mathbb P^n(\mathbb C)$ and moving hyperplanes with truncated counting functions. Our results are improvements of the previous second main theorems for moving hyperplanes with truncated (to level $n$) counting functions.
description: This version is a shortened version of the first one by removing the part on the unicity of meromorphic mappings. This paper is accepted for publication in Proceedings of the American Mathematical Society (2018). arXiv admin note: text overlap with arXiv:1402.3156
Massive stealth scalar fields from field redefinition method
Creators: name: Quinzacara, Cristian C.
name: Meza, Paola
name: Sampson, Almeira
name: Valenzuela, Mauricio
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We propose an uni-parametric deformation method of action principles of scalar fields coupled to gravity which generates new models with massive stealth field configurations, i.e. with vanishing energy-momentum tensor. The method applies to a wide class of models and we provide three examples. In particular we observe that in the case of the standard massive scalar action principle, the respective deformed action contains the stealth configurations and it preserves the massive ones of the undeformed model. We also observe that, in this latter example, the effect of the energy-momentum tensor of the massive (non-stealth) field can be amplified or damped by the deformation parameter, alternatively the mass of the stealth field.
description: 12 pages
Outrage
Publisher: name: Columbia University
Year: 2021
Subjects: Gay liberation movement
Gay activists
Transgender people
Homophobia
Transphobia
Stonewall Riots (New York, New York : 1969)

description: Episode 1 “Outrage” of the documentary “The Question of Equality”. Features interviews with people like Randy Wicker and Sylvia Rivera about the lead-up to the Stonewall Rebellion. The video also covers the tumultuous period in the years following Stonewall. Produced by the Corporation for Public Broadcasting
Logic Programs as Declarative and Procedural Bias in Inductive Logic Programming
Creators: name: Lin, Dianhuan
Publisher: name: Imperial College London
Year: 2013

description: Machine Learning is necessary for the development of Artificial Intelligence, as pointed out by Turing in his 1950 article ``Computing Machinery and Intelligence''. It is in the same article that Turing suggested the use of computational logic and background knowledge for learning. This thesis follows a logic-based machine learning approach called Inductive Logic Programming (ILP), which is advantageous over other machine learning approaches in terms of relational learning and utilising background knowledge. ILP uses logic programs as a uniform representation for hypothesis, background knowledge and examples, but its declarative bias is usually encoded using metalogical statements. This thesis advocates the use of logic programs to represent declarative and procedural bias, which results in a framework of single-language representation. We show in this thesis that using a logic program called the top theory as declarative bias leads to a sound and complete multi-clause learning system MC-TopLog. It overcomes the entailment-incompleteness of Progol, thus outperforms Progol in terms of predictive accuracies on learning grammars and strategies for playing Nim game. MC-TopLog has been applied to two real-world applications funded by Syngenta, which is an agriculture company. A higher-order extension on top theories results in meta-interpreters, which allow the introduction of new predicate symbols. Thus the resulting ILP system Metagol can do predicate invention, which is an intrinsically higher-order logic operation. Metagol also leverages the procedural semantic of Prolog to encode procedural bias, so that it can outperform both its ASP version and ILP systems without an equivalent procedural bias in terms of efficiency and accuracy. This is demonstrated by the experiments on learning Regular, Context-free and Natural grammars. Metagol is also applied to non-grammar learning tasks involving recursion and predicate invention, such as learning a definition of staircases and robot strategy learning. Both MC-TopLog and Metagol are based on a $\top$-directed framework, which is different from other multi-clause learning systems based on Inverse Entailment, such as CF-Induction, XHAIL and IMPARO. Compared to another $\top$-directed multi-clause learning system TAL, Metagol allows the explicit form of higher-order assumption to be encoded in the form of meta-rules.
Profiling guide dog handlers to support guide dog matching decisions
Creators: name: Meyer, Denny
name: Jahar Bhowmik
name: Fakir M. Amirul Islam
name: Deverell, Lil
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Science Policy

description: Purpose: This Australian study piloted a new measure of Orientation and Mobility to better understand the functional mobility of guide dog handlers with low vision or blindness. It is expected that this measure can be used to better match guide dogs to their handlers. Materials and methods: The new Orientation and Mobility Outcomes tool scores a client in Stable/Familiar and Dynamic/Unfamiliar conditions, also considering Travel-Related Wellbeing. Semi-structured interviews were conducted with 51 guide dog handlers, during which travel skills were co-rated with an interviewer. Results: A cluster analysis of the Orientation and Mobility Outcomes data identified four mobility styles: intrepid explorers, social navigators, independent roamers and homebodies. The differences between these clusters had more to do with mental mapping skills than level of vision, and different guide dog characteristics were needed to support the travel styles identified for each cluster. Conclusions: The results confirm the importance of the Orientation and Mobility Outcomes tool as a sensitive, person-centred measure of the impact of Orientation and Mobility and guide dog training. In particular, the four mobility clusters provide a new perspective on matching guide dogs with clients, also suggesting the need for a more personalised look at the guide dog training process.Implications for RehabilitationOrientation and Mobility Outcomes data seem precise enough to support and inform the process of matching guide dogs to handlers.Uniform results cannot be expected from guide dog mobility in handlers – age, stage of life, health and spatial cognition impact the competence and travel style of guide dog handlers, whereas vision is less important.Sharing the work of visual interpretation and decision making with a guide dog makes independent travel more possible.Valuable dog characteristics that are specific to handler requirements might be bred or trained from puppy raising onwards, creating a more diverse pool of dogs to draw upon. Orientation and Mobility Outcomes data seem precise enough to support and inform the process of matching guide dogs to handlers. Uniform results cannot be expected from guide dog mobility in handlers – age, stage of life, health and spatial cognition impact the competence and travel style of guide dog handlers, whereas vision is less important. Sharing the work of visual interpretation and decision making with a guide dog makes independent travel more possible. Valuable dog characteristics that are specific to handler requirements might be bred or trained from puppy raising onwards, creating a more diverse pool of dogs to draw upon.
Multi-scale analysis of turbulence evolution in the density stratified intracluster medium
Creators: name: Shi, Xun
name: Nagai, Daisuke
name: Lau, Erwin
Publisher: name: arXiv
Year: 2018
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The diffuse hot medium inside clusters of galaxies typically exhibits turbulent motions whose amplitude increases with radius, as revealed by cosmological hydrodynamical simulations. However, its physical origin remains unclear. It could either be due to an excess injection of turbulence at large radii, or faster turbulence dissipation at small radii. We investigate this by studying the time evolution of turbulence in the intracluster medium (ICM) after major mergers, using the Omega500 non-radiative hydrodynamical cosmological simulations. By applying a novel wavelet analysis to study the radial dependence of the ICM turbulence spectrum, we discover that faster turbulence dissipation in the inner high density regions leads to the increasing turbulence amplitude with radius. We also find that the ICM turbulence at all radii decays in two phases after a major merger: an early fast decay phase followed by a slow secular decay phase. The buoyancy effects resulting from the ICM density stratification becomes increasingly important during turbulence decay, as revealed by a decreasing turbulence Froude number $Fr \sim \mathcal{O}(1)$. Our results indicate that the stronger density stratification and smaller eddy turn-over time are the likely causes of the faster turbulence dissipation rate in the inner regions of the cluster.
description: 8 pages, 7 figures, accepted to MNRAS
Chromium Poisoning of Cathodes in the SOFC
Creators: name: Lee, Soo-Na
Publisher: name: Imperial College London
Year: 2014

description: Mixed Ionic Electronic Conductors (MIECs) such as La0.6Sr0.4Co0.2Fe0.8O3­δ (LSCF) and La2NiO4+δ (LNO) are gaining much attention as candidate cathode materials at reduced working temperatures (600-800°C), because they exhibit better oxygen transport properties, in comparison to earlier cathode materials such as LaxSr1­xMnyO3­δ (LSM). The main objective of the study in this thesis is establishing the relationship between the amount of chromium and performance degradation of LSCF and Sr-free LNO cathodes, and improving understanding of the mechanism. LSCF were screen printed onto Ce0.9Gd0.1O1.95 (CGO10) electrolyte pellets and infiltrated with chromium nitrate solutions to different Cr levels up to 2wt%. Electrochemical impedance spectroscopy at 500 ~ 800C showed that even very low levels of Cr give a significant increase in cathode polarisation resistance, which increases with Cr concentration. The impedance response was analysed using the model of Adler, Lane and Steele (ALS model) to extract oxygen self-diffusion (Do) and surface exchange (ko) parameters for the LSCF. The results show that Cr reduces both Do and ko, the latter being the more affected. However, the activation energies for polarisation resistance, Do and ko are not significantly affected by Cr content. This indicates that the Cr poisoning mechanism involves the de-activation of sites for oxygen exchange on the LSCF surface and that the cathode's residual activity is by means of remaining active sites. The surface reaction and diffusion of oxygen in dense LSCF was studied by oxygen isotope exchange using bulk specimens and depth profile analysis. The specimen surfaces were coated with different thicknesses of Cr2O3 by sputtering prior to exchange. The results showed that the Cr2O3 surface layer had a large inhibiting effect on ko, in agreement with the electrochemical measurements, but a negligible effect on Do because diffusion of Cr into the bulk was very slow. The effect of Cr on Sr-free LNO electrodes deposited symmetrically onto Ce0.9Gd0.1O1.95 (CGO10) electrolytes by screen printing was studied in a similar way. XRD of LNO/Cr2O3 powder mixtures annealed at 1000C for 24h showed that LNO reacts readily with Cr2O3 to form LaCrO3 and LaNiO3. Despite this reactivity, the electrochemical experiments show that the polarisation resistance of LNO cathodes is insensitive to Cr introduced by solution infiltration for Cr concentrations up to 1%. For concentrations above this level the Cr increases the polarisation resistance, but to a much lesser degree in comparison to LSCF. Cr reduces the rate of the oxygen reduction reaction on the LNO surfaces, but does not change the activation energy significantly. The relatively good tolerance of LNO cathodes to Cr ingress is probably due to the reaction products themselves having some useful catalytic activity for oxygen reduction.
title: ADCO, Cartulaire de Cîteaux pour les possessions de Dijon et du Dijonnais (XVe siècle), Cart. 175 (11 H 479), 115 folios, f. 0181
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/2017
name: Petot, Frédéric
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2020
Subjects: subject: LaMOP
subject: Laboratoire de Médiévistique Occidentale de Paris
subject: Corpus Burgundiae Medii Aevi
subject: Chartes de la Bourgogne du Moyen Âge
subject: cartulaire

description: Cartulaire de Cîteaux pour les possessions de Dijon et du Dijonnais (XVe siècle), Archives départementales de la Côte-d'Or, Cart. 175 (11 H 479), 115 folios, f. 0181, Numérisation en mode image.
description: Relation: http://www.cbma-project.eu/
description: Bibliographic citation: Cartulaire de Cîteaux pour les possessions de Dijon et du Dijonnais (XVe siècle), Archives départementales de la Côte-d'Or, Cart. 175 (11 H 479), 115 folios, f. 0181, in Projet CBMA - Corpus Burgundiae Medii Aevi [Ressource en ligne], https:// manuscrits.cbma-project.eu/
description: Provenance: abbaye de Cîteaux
description: Provenance: http://www.wikidata.org/entity/Q843261
description: Provenance: https://www.geonames.org/3024876
description: Provenance: http://www.idref.fr/030974844/id
description: Provenance: https://catalogue.bnf.fr/ark:/12148/cb12228351v
Uncertainty in statistical downscaling of rainfall: Case study of south-east UK
Creators: name: Duan, Juan
Publisher: name: Imperial College London
Year: 2013

description: Pressures on water resources in much of England are set to rise owing to factors such as climate change and population growth. This is particularly the case in south-east UK, with its high population density, relatively low number of reservoirs and heavy reliance on groundwater supplies. Investigating the sustainability of water supply in this region requires a better understanding the rainfall distribution both temporally and spatially. Statistical downscaling methods were commonly adopted to simulate rainfall including under climate change scenarios. When projecting the downscaling model into future, it is often assumed that the statistical relationships observed in the historical fitting period remain stationary under the climate scenarios. However, this assumption is questionable as many downscaling models are trained on only around 30 years of data. The objectives of the thesis are therefore to 1) develop long-term statistical downscaling rainfall models to characterise the spatial and temporal distribution of rainfall for south-east UK; 2) identify the non-stationarity in statistical downscaling models; and 3) project the rainfall under climate change scenarios and assess the uncertainties in rainfall projections. To address these challenges, regression models of monthly rainfall for south-east UK were developed. Conditioned on 50 gauged sites, the model infilled and simulated the historic record from 1855-2011 in both space and time. The long record length allows more insight into the variability of rainfall and potentially a stronger basis for risk assessment than is generally possible. It is shown that, although localised biases exist in both space and time, the model results are generally consistent with the observed record including for a range of inter-annual droughts and spatial statistics. The non-stationarity was then assessed using two approaches, including visualising the non-stationarity by plotting the time series of regression coefficient estimates derived by using a moving window of 30 years, and testing whether the decadal scale change in the coefficient values is statistically significant. The results illustrate the existence of significant non-stationarity in the model, which could not be removed by adding additional available input variables to the regression. The models fitted from five 30-year control periods and climate data from five GCMs were used to generate rainfall projections in 2021-2050. Both the uncertainty introduced by non-stationarity and the GCMs was visualised. The results show that in some months the source of uncertainty introduced by non-stationarity can lead to significant uncertainty in the projections. The uncertainties in projections were then estimated using ensembles.
Professional Tennis: Quantitative Models and Ranking Algorithms
Creators: name: Spanias, Demetris
Publisher: name: Imperial College London
Year: 2014

description: Professional singles tennis is a popular global sport that attracts spectators and speculators alike. In recent years, financial trading related to sport outcomes has become a reality, thanks to the rise of online betting exchanges and the ever increasing development and deployment of quantitative models for sports. This thesis investigates the extent to which the outcome of a match between two professional tennis players can be forecast using quantitative models parameterised by historical data. Three different approaches are explored, each having its own advantages and disadvantages. Firstly, the problem is approached using a Markov chain to model a tennis point, estimating the probability of a player winning a point while serving. Such a probability can be used as a parameter to existing hierarchical models to estimate the probability of a player winning the match. We demonstrate how this probability can be estimated using varying subsets of historical player data and investigate their effect on results. Averaged historical data over varying opponents with different skill sets, does not necessarily provide a fair basis of comparison when evaluating the performance of players. The second approach presented is a technique that uses data, which includes only matches played against common opponents, to find the difference between the modelled players’ probability of winning a point on their serve against each common opponent. This difference in probability for each common opponent is a “transitive contribution” towards victory for the match being modelled. By combining these “contributions” the “Common-Opponent” model overcomes the problems of using average historical statistics at the cost of a shrinking data set. Finally, the thesis ventures into the field of player rankings. Rankings provide a fast and simple method for predicting match winners and comparing players. We present a variety of methods to generate such player rankings, either by making use of network analysis or hierarchical models. The generated rankings are then evaluated using their ability to correctly represent the subset of matches that were used to generate them as well as their ability to forecast future matches.
Profiling guide dog handlers to support guide dog matching decisions
Creators: name: Meyer, Denny
name: Jahar Bhowmik
name: Fakir M. Amirul Islam
name: Deverell, Lil
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Science Policy

description: Purpose: This Australian study piloted a new measure of Orientation and Mobility to better understand the functional mobility of guide dog handlers with low vision or blindness. It is expected that this measure can be used to better match guide dogs to their handlers. Materials and methods: The new Orientation and Mobility Outcomes tool scores a client in Stable/Familiar and Dynamic/Unfamiliar conditions, also considering Travel-Related Wellbeing. Semi-structured interviews were conducted with 51 guide dog handlers, during which travel skills were co-rated with an interviewer. Results: A cluster analysis of the Orientation and Mobility Outcomes data identified four mobility styles: intrepid explorers, social navigators, independent roamers and homebodies. The differences between these clusters had more to do with mental mapping skills than level of vision, and different guide dog characteristics were needed to support the travel styles identified for each cluster. Conclusions: The results confirm the importance of the Orientation and Mobility Outcomes tool as a sensitive, person-centred measure of the impact of Orientation and Mobility and guide dog training. In particular, the four mobility clusters provide a new perspective on matching guide dogs with clients, also suggesting the need for a more personalised look at the guide dog training process.Implications for RehabilitationOrientation and Mobility Outcomes data seem precise enough to support and inform the process of matching guide dogs to handlers.Uniform results cannot be expected from guide dog mobility in handlers – age, stage of life, health and spatial cognition impact the competence and travel style of guide dog handlers, whereas vision is less important.Sharing the work of visual interpretation and decision making with a guide dog makes independent travel more possible.Valuable dog characteristics that are specific to handler requirements might be bred or trained from puppy raising onwards, creating a more diverse pool of dogs to draw upon. Orientation and Mobility Outcomes data seem precise enough to support and inform the process of matching guide dogs to handlers. Uniform results cannot be expected from guide dog mobility in handlers – age, stage of life, health and spatial cognition impact the competence and travel style of guide dog handlers, whereas vision is less important. Sharing the work of visual interpretation and decision making with a guide dog makes independent travel more possible. Valuable dog characteristics that are specific to handler requirements might be bred or trained from puppy raising onwards, creating a more diverse pool of dogs to draw upon.
Numerical simulation of slug flow with high viscosity liquid
Creators: name: Hor, Yat Ho Nicholas
Publisher: name: Imperial College London
Year: 2013

description: Slug flow is one of the most common flow patterns in multiphase oil/gas transport in pipelines. Due to its complexity, it poses numerous challenges to model development. Industrial slug flow models are one-dimensional and can give poor predictions in situations where the associated closures and simplifications are no longer valid. Computational Fluid Dynamics (CFD) facilitates high-resolution studies of slug flow dynamics by implementing multi-dimensional models. Understanding the physics of slug flow would help identify the main flow mechanisms to be modelled and enable the development of mechanistic slug flow models for commercial software. In this thesis, a computational approach is developed. The front tracking method (FTM) (Tryggvason et al. 2001) and the phase field method (PFM) (Ding et al. 2007) are used to model long bubbles in slug flows. Results of the validation study show good agreement with DeBisschop et al. (2002), who performed simulations of long bubbles in two-dimensional channels in the creeping-flow limit. Their work is extended here to moderate Archimedes numbers (10 < Ar < 200). The effects of inertia, surface tension, viscosity and inclination angle on the terminal velocity and the shape of a long bubble in different flow conditions are investigated. Furthermore, the FTM is coupled with a discrete bubble tracking method (DBTM), which has resulted in a robust hybrid method to model small and large bubbles simultaneously in an Eulerian-Lagrangian fashion. The method allows the study of the interaction of the small bubbles with a long bubble. The work is extended further to three dimensions using the PFM. The validation study shows good agreement with the present two-dimensional numerical work. The geometry is converted from a square channel to a pipe to facilitate a more realistic simulation of slug flow in pipelines. This work will provide a rigorous basis for developing simplified models.
Induced pluripotent stem cells as an alternative to embryonic stem cells for the treatment of type 1 diabetes
Creators: name: Francis, Natalie
Publisher: name: Imperial College London
Year: 2014

description: Type 1 diabetes mellitus (T1DM) results from auto-immune destruction of the insulin-secreting β-cells of the pancreas. The most common treatment is injection of exogenous insulin, but this allows only partial control over blood glucose levels, so other therapies are needed. Pancreatic islet transplantation has shown proof of principle for cell replacement therapy to treat T1DM. There are several sources of cells which could be used, but much of the focus has been on pluripotent stem cells, which are able to self-renew indefinitely in culture and give rise to any cell in the body. Insulin-expressing cells have successfully been produced from embryonic stem cells (ESCs) by recapitulating embryonic development in vitro. However, problems associated with the use of ESCs mean that an alternative cell source is needed. In 2006, it was discovered that 4 transcription factors can reprogram somatic cells into induced pluripotent stem cells (iPSCs). iPSCs provide an alternative source of pluripotent stem cells and can be derived in a patient-specific manner. iPSCs have been shown to differentiate in vitro into insulin-expressing cells, but it is unknown whether iPSCs are truly equivalent to ESCs. Important differences have been shown to exist between iPSCs and ESCs which may affect the ability of iPSCs to give rise to cells of a pancreatic lineage and therefore limit their usefulness for the treatment of T1DM. The aim of this project is to identify whether iPSCs are a viable alternative to ESCs for generating β-cells in vitro for cell replacement therapy to treat type 1 diabetes. The differentiation potential of iPSCs and ESCs to give rise to first definitive endoderm (the first stage in differentiation towards a pancreatic lineage) in vitro will be compared, and the involvement of miRNAs in differentiation of ESCs and iPSCs to definitive endoderm will be investigated.
Precision of T2 TSE MRI-CT-image fusions based on gold fiducials and repetitive T2 TSE MRI-MRI-fusions for adaptive IGRT of prostate cancer by using phantom and patient data
Creators: name: D. Wegener
name: D. Zips
name: D. Thorwarth
name: J. Weiß
name: A. E. Othman
name: U. Grosse
name: M. Notohamiprodjo
name: K. Nikolaou
name: A. C. Müller
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Space Science
subject: Medicine
subject: Cell Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Biotechnology
subject: Cancer

description: Introduction: To increase precision of radiation treatment (RT) delivery in prostate cancer, MRI-based RT as well as the use of fiducials like gold markers (GMs) have shown promising results. Their combined use is currently under investigation in clinical trials. Here, we aimed to evaluate a workflow of image registration based on GMs between CT and MRI as well as weekly MRI-MRI adaption based on T2 TSE sequence. Material and methods: A gel-phantom with two inserted GMs was scanned with CT and three different MR-scanners of 1.5 and 3 T (T2 TSE and T1 VIBE-Dixon, isotropic, voxel size 2 × 2 × 2 mm). After image fusion, deviations for fiducial and gel match were measured and artifacts were evaluated. Additionally, CT-MRI-match deviations and MRI-MRI-match deviations of 10 Patients from the M-basePro study using GMs were assessed. Results: GMs were visible in all imaging modalities. The outer gel contours were matched with <1 mm deviation, contour volumes varied between 0 and 1%. The deviations of the GMs were less than 2 mm in any direction of MRI/CT. Shifts of peripherally or centrally located GMs were randomly distributed. The average MRI-CT-match precision of 10 patients with GMs was 1.9 mm (range 1.1–3.1 mm). Conclusions: Match inaccuracies for GMs between reference CT and voxel-isotropic T2-TSE sequences are small. Spatial deviations of CT- and MR-contoured fiducials were less than 2 mm, i.e., below SLT of the applied modalities. In patients, the average CT-MRI-match precision for GMs was 1.9 mm supporting their use in MR-guided high precision RT. Trial registration:ClinicalTrials.gov identifier: NCT02724670.
Can Rocky Exoplanets with Rings Pose as Sub-Neptunes?
Creators: name: Piro, Anthony L.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: In our solar system, the presence of rings is exclusive to the gas giants, but is this the case for all planetary systems? In principle, it seems that rocky exoplanets could also have rings, which could be searched for by studying their subtle imprint on the ingress and egress of transits. Unfortunately, such effects are difficult to measure and require high precision photometric and/or spectroscopic observations. At the most basic level though, the presence of rings would result in an increased transit depth that could be mistaken as an anonymously large radius. Motivated by this, I consider how a population of exoplanets with rings would impact radius measurements, focusing on Earth-like exoplanets. It is found that this population introduces an enhancement of inferred radii in the range of $\sim2-3R_\oplus$, not unlike the sub-Neptunes that have been identified in recent transit surveys. Whether rings can explain all or most sub-Neptunes seems difficult, since it would require a large fraction of rocky planets to have rings ($\gtrsim40\%$) and/or a factor of $\sim2-3$ increase in the number of planets with radii $\lesssim1.2R_\oplus$. Even if rings cannot explain all sub-Neptunes, this work suggests that focusing on those planets currently classified as sub-Neptunes may be a good starting place for finding rocky planets with rings.
description: 9 pages, 7 figures, fixed obliquity distribution for version accepted for publication in AJ
Cluster Abundance Constraints on Quintessence Models
Creators: name: Wang, Limin
name: Steinhardt, Paul J.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The abundance of rich clusters is a strong constraint on the mass power spectrum. The current constraint can be expressed in the form $σ_8 Ω_m^γ = 0.5 \pm 0.1$ where $σ_8$ is the $rms$ mass fluctuation on 8 $h^{-1}$ Mpc scales, $Ω_m$ is the ratio of matter density to the critical density, and $γ$ is model-dependent. In this paper, we determine a general expression for $γ$ that applies to any models with a mixture of cold dark matter plus cosmological constant or quintessence (a time-evolving, spatially-inhomogeneous component with negative pressure) including dependence on the spectral index $n$, the Hubble constant $h$, and the equation-of-state of the quintessence component $w$. The cluster constraint is combined with COBE measurements to identify a spectrum of best-fitting models. The constraint from the evolution of rich clusters is also discussed.
description: 19 pages, 4 figures, submitted to ApJ
Control of AC/DC systems for improved transient stability and frequency support provision
Creators: name: Martínez Sanz, Inmaculada
Publisher: name: Imperial College London
Year: 2014

description: In this thesis, control of future AC/DC systems for improved system dynamic performance is studied. The objective is to determine mechanisms for providing AC network services (e.g. frequency support, damping, etc.) through coordinated control of HVDC power converters and FACTS devices while considering increased levels of wind generation. In particular, this work addresses some of the concerns associated with the stability of the future Great Britain (GB) transmission network as it evolves to support low carbon generation scenarios and the use of DC grids to integrate offshore renewable resources and form a sub-sea interconnection across Europe. The contributions of this thesis are in two main areas: emergency control for power system stabilization and exchange of frequency support across a DC grid. Fast control of FACTS devices and HVDC links can be exercised as a post-fault corrective action to maintain system stability without the need of constraining pre-fault transfer levels. This work employs a model predictive control (MPC) scheme that relies on system wide-area measurements to preserve the system stability after critical contingencies. MPC can explicitly account for system constraints and changing operating conditions and is therefore suited for on-line applications and power electronic actuators with limited short-term overload capability. The effectiveness of the proposed approach is demonstrated using time domain simulations on representative equivalent models of the future GB transmission network. A detailed analysis of the dynamic behaviour and stability issues associated with the GB transmission grid have also been presented. In the DC grid context, this thesis investigates the provision of frequency services considering frequency droop loops in the control of the converters. The interaction between onshore AC systems and a DC grid is analyzed through an extended steady-state formulation. A methodology for providing frequency response from offshore wind farms connected through a DC grid is also proposed. The performance of this scheme is illustrated both analytically and also through simulation results.
Fluorescent Zn(II) coordination polymer constructed by (R)-2-(1-carboxyethoxy)terephthalic acid as a probe for selective identification of Cr2O72− and MnO4−
Creators: name: Xu, Zhong-Xuan
name: Shi, Ming-Feng
name: Wan, Yi
name: Wu, Men-Jie
name: Yin, Xiu-Ju
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biophysics
subject: Biochemistry
subject: Physical Sciences not elsewhere classified
subject: Molecular Biology
subject: Physiology
subject: FOS: Biological sciences
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified

description: Ligand (R)-2-(1-carboxyethoxy)terephthalic acid ((R)-H3CTA) with excellent fluorescence has been prepared from (S)-methyl lactate and 2-hydroxyterephthalic acid. With the help of 4,4′-bipyridine (4,4′-BIP), (R)-H3CTA assembled with Zn2+ to obtain {[Zn((R)-CTA)(4,4′-BIP)2] · H2O}n (HU13-R) under hydrothermal conditions. In HU13-R, (R)-CTA3− anions and Zn(II) centers resulted in a (R)-CTA-Zn layer, and then adjacent (R)-CTA-Zn layers and 4,4′-BIP ligands further formed a typical pillared-layer structure with a (3,5)-connected net. Besides excellent water stability, HU13-R has strong solid-state fluorescence. As a bright luminescent material, detection limit from HU13-R is up to 3.22 × 10−6 M for Cr2O72− and 5.92 × 10−6 M for MnO4−, showing high sensitivity for anions. The presence of different anions does not interfere with its recognition ability for Cr2O72− and MnO4−.
Table S7 calculation detail about energy from Synthesis of novel technetium-99 m tricarbonyl-HBED-CC complexes and structural prediction in solution by density functional theory calculation
Creators: name: Shi, Shengyu
name: Yao, Lifeng
name: Li, Linlin
name: Wu, Zehui
name: Zha, Zhihao
name: Kung, Hank F.
name: Zhu, Lin
name: Fang, De-Cai
Publisher: name: The Royal Society
Year: 2019

description: HBED-CC (N,N'-Bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid, L1) is a common bifunctional chelating agent in preparation of 68Ga-radiopharmaceuticals. Due to its high stability constant for the Ga3+ complex (logKGaL = 38.5) and its acyclic structure, it is well known for a rapid and efficient radiolabelling at ambient temperature with Gallium-68 and its high in vivo stability. [99 mTc][Tc(CO)3(H2O)3]+ is an excellent precursor for radiolabelling of biomolecules. The aim of this study was to develop a novel preparation method of 99 mTc-HBED-CC complexes. In this study, HBED-CC-NI (2,2'-(ethane-1,2-diylbis((2-hydroxy-5-(3-((2-(2-nitro-1H-imidazol-1-yl)ethyl)amino)-3-oxopropyl)benzyl)-azanediyl))-diacetic acid, L2), a derivative of HBED-CC, was designed and synthesized. Both L1 and L2 were radiolabelled by [99 mTc][Tc(CO)3(H2O)3]+ successfully for the first time. In order to explore the coordination mode of metal and chelates, non-radioactive Re(CO)3L1 and Re(CO)3L2 were synthesized and characterized spectroscopically. Tc(CO)3L1 and Tc(CO)3L2 in solution were calculated by density functional theory and were analysed with radio-HPLC chromatograms. It showed that [99 mTc]Tc(CO)3L2 forms two stable diastereomers in solution, which is similar to those of [68Ga]Ga-HBED-CC complexes. Natural bond orbital analysis through the natural population charges revealed a charge transfer between [99 mTc][Tc(CO)3]+ and L1 or L2. The experimental results showed that tricarbonyl technetium might form stable complex with HBED-CC derivatives, which is useful for the future application of using HBED-CC as a bifunctional chelating agent in developing new 99 mTc-radiopharmaceuticals as diagnostic imaging agents.
Moduli Spaces of Symmetric Cubic Fourfolds and Locally Symmetric Varieties
Creators: name: Yu, Chenglong
name: Zheng, Zhiwei
Publisher: name: arXiv
Year: 2018
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: In this paper we realize the moduli spaces of cubic fourfolds with specified automorphism groups as arithmetic quotients of complex hyperbolic balls or type IV symmetric domains, and study their compactifications. Our results mainly depend on the well-known works about moduli space of cubic fourfolds, including the global Torelli theorem proved by Voisin ([Voi86]) and the characterization of the image of the period map, which is given by Laza ([Laz09, Laz10]) and Looijenga ([Loo09]) independently. The key input for our study of compactifications is the functoriality of Looijenga compactifications, which we formulate in the appendix (section A). The appendix can also be applied to study the moduli spaces of singular K3 surfaces and cubic fourfolds, which will appear in a subsequent paper.
description: 27 pages, comments welcome!!
Naive Bayesian Learning in Social Networks
Creators: name: Anunrojwong, Jerry
name: Sothanaphan, Nat
Publisher: name: arXiv
Year: 2018
Subjects: subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: The DeGroot model of naive social learning assumes that agents only communicate scalar opinions. In practice, agents communicate not only their opinions, but their confidence in such opinions. We propose a model that captures this aspect of communication by incorporating signal informativeness into the naive social learning scenario. Our proposed model captures aspects of both Bayesian and naive learning. Agents in our model combine their neighbors' beliefs using Bayes' rule, but the agents naively assume that their neighbors' beliefs are independent. Depending on the initial beliefs, agents in our model may not reach a consensus, but we show that the agents will reach a consensus under mild continuity and boundedness assumptions on initial beliefs. This eventual consensus can be explicitly computed in terms of each agent's centrality and signal informativeness, allowing joint effects to be precisely understood. We apply our theory to adoption of new technology. In contrast to Banerjee et al. [2018], we show that information about a new technology can be seeded initially in a tightly clustered group without information loss, but only if agents can expressively communicate their beliefs.
description: 30 pages, 1 figure, appears in proceedings of the 19th ACM conference on Economics and Computation (ACM EC'18)
Status Report on Weak Matrix Element Calculations
Creators: name: Gupta, Rajan
name: Bhattacharya, Tanmoy
Publisher: name: arXiv
Year: 1995
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: This talk presents results of weak matrix elements calculated from simulations done on 170 $32^3 \times 64$ lattices at $β= 6.0$ using quenched Wilson fermions. We discuss the extraction of pseudoscalar decay constants $f_π$, $f_K$, $f_D$, and $f_{D_s}$, the form-factors for the rare decay $B \to K^* γ$, and the matrix elements of the 4-fermion operators relevant to $B_K$, $B_7$, $B_8$. We present an analysis of the various sources of systematic errors, and show that these are now much larger than the statistical errors for each of these observables. Our main results are $f_D=186(29) \MeV$, $f_{D_s}=224(16) MeV$, $T_1=T_2=0.24(1)$, $B_K(NDR, 2\GeV)=0.67(9)$, and $B_8(NDR, 2\GeV)=0.81(1)$.
description: 8 pages. Talks presented at Lattice 95. Latex. Modified "axis" source for figures also included
Impact of anisotropic interactions on non-equilibrium cluster growth at surfaces
Creators: name: Martynec, Thomas
name: Klapp, Sabine H. L.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Using event-driven kinetic Monte-Carlo simulations we investigate the early stage of non-equilibrium surface growth in a generic model with anisotropic interactions among the adsorbed particles. Specifically, we consider a two-dimensional lattice model of spherical particles where the interaction anisotropy is characterized by a control parameter $η$ measuring the ratio of interaction energy along the two lattice directions. The simplicity of the model allows us to study systematically the effect and interplay between $η$, the nearest-neighbor interaction energy $E_{n}$, and the flux rate $F$, on the shapes and the fractal dimension $D_{f}$ of clusters before coalescence. At finite particle flux $F$ we observe the emergence of rod-like and needle-shaped clusters whose aspect ratio $R$ depends on $η$, $E_{n}$ and $F$. In the regime of strong interaction anisotropy, the cluster aspect ratio shows power-law scaling as function of particle flux, $R \sim F^{- α}$. Furthermore, the evolution of the cluster length and width also exhibit power-law scaling with universal growth exponents for all considered values of $F$. We identify a critical cluster length $L_{c}$ that marks a transition from one-dimensional to self-similar two-dimensional cluster growth. Moreover, we find that the cluster properties depend markedly on the critical cluster size $i^{*}$ of the isotropically interacting reference system ($η= 1$).