The evolution of conifolds

We simulate the gravitational dynamics of the conifold geometries (resolved and deformed) involved in the description of certain compact spacetimes. As the cycles of the conifold collapse towards a singular geometry we find that a horizon develops, shielding the external spacetime from the curvature singularity of the newly formed black hole. The structure of the black hole is examined for a range of initial conditions, and we find a candidate black-hole solution for the final state of the collapse.Comment: 22 pages, 6 figure

Human resource development for educational eletronic media practitioners: a new paradigm

A Dissertation Submitted to the Faculty of Arts University of Witwatersrand Johannesburg For the Degree of Master of Arts Johannesburg, 1995The aim of this thesis is to develop a new paradigm for the human resource development of educational electronic media practitioners, including both users and producers of educational electronic media materials. The thesis begins by placing the problem in context. This it does .by considering bJ;iefly the educational needs facing South Africa and the role which the electronic<fnedia have to play in dealing with some of these needs. An opening rationale is also provided for why human resource development is targeted as the focus of the thesis. Following this, the thesis provides both a broader educational context and a theoretical basis for the new paradigm by introducing the concepts of open learning and distance education. The discussion of these concepts has two further functions; to strengthen the rationale for the use of the electronic media in education and to provide principles and methods of practice which lie at the heart of the new paradigm being developed. A further section on constraints in education develops some of the themes emerging in greater detail. The rest of the thesis focuses on providing details, both practically and theoretically orientated, which complete the paradigm. Separar, sections are devoted to users and producers of educational electronic media materials, in an effort to shift greater emphasis the users of such materials. Finally, the notion of macro coordinating structures, as art element essential for the successful implementation of the new paradigm, is discussed.MT201

The influence of gravity upon topology changing transitions and warped flux compactifications

We investigate the dynamics of the geometric transitions associated to compactified spacetimes. By including the effects of gravity we are able to follow the evolution of collapsing cycles as they attempt to undergo a topology changing transition. We perform investigations where we add a perturbation to the momentum of a static solution and observe the consequences this has on the spacetime, looking for evidence of black hole formation or collapsing cycles which could lead to singular geometry. First we look into two possible four dimensional spacelike solutions to the Einstein equations called instantons. These both have a two-sphere at the origin, these are called bolt singularities. We introduce an initial perturbation to reduce the two-sphere to a point. Rather than achieving this singular geometry we find that either a horizon forms, shielding a curvature singularity, or the cycle re-expands after an initial contraction phase. For the case where a horizon forms we identify the final state with a known analytic black-hole solution. In seven dimensions we simulate the gravitational dynamics of the conifold geometries (resolved and deformed) involved in the description of certain compact spacetimes. As the cycles of the conifold collapse towards a singular geometry we inevitably find that a horizon develops, shielding the external spacetime. The structure of the black hole is examined and we find a candidate for the final state of the collapse. In ten dimensions we investigate the time evolution due to gravitational dynamics of a spacetime which is commonly used in brane-cosmology and string compactifications called the Klebanov-Strassler geometry. Here black holes are sometimes formed but more commonly the cycles are seen to re-expand after reaching a minimum value, showing the stability of the solution against perturbations which would change its size

A basic guide to open educational resources (OER)

133 p. : ill.Libro ElectrónicoThis Guide comprises three sections. The first – a summary of the key issues – is presented in the form of a set of ‘Frequently Asked Questions’. Its purpose is to provide readers with a quick and user-friendly introduction to Open Educational Resources (OER) and some of the key issues to think about when exploring how to use OER most effectively. The second section is a more comprehensive analysis of these issues, presented in the form of a traditional research paper. For those who have a deeper interest in OER, this section will assist with making the case for OER more substantively. The third section is a set of appendices, containing more detailed information about specific areas of relevance to OER. These are aimed at people who are looking for substantive information regarding a specific area of interestContents Acknowledgements 1 Overview of the Guide 3 A Basic Guide to Open Educational Resources: Frequently asked questions 5 What are Open Educational Resources (OER)? 5 Is OER the same as e-learning? 5 Is OER the same as open learning/open education? 6 Is OER related to the concept of resource-based learning? 7 How open is an open licence? 8 What is the difference between OER and open access publishing? 9 Shouldn’t I worry about ‘giving away’ my intellectual property? 9 Who will guarantee the quality of OER? 12 How can education benefit by harnessing OER? 13 Is OER really free? 14 Does use of OER preclude use of commercial content? 16 What policy changes are needed for institutions to make more effective use of OER? 16 What are the best ways to build capacity in OER? 17 Where do I find OER? 18 How can I share my OER with others? 19 How much can I change OER for my own purposes? 20 Making the Case for Open Educational Resources 23 Introduction 23 Defining the concept 24 The implications for educational planners and decision-makers 39 Conclusion 44 References 45 Appendix One: Overview of Open Licences 47 Introduction 47 Creative Commons Licences 48 Appendix References 52 Appendix Two: The Components of a Well-Functioning Distance Education System 53 The Components 53 The Rationale for Use of Distance Education Methods 55 Appendix Three: Technology Applications 57 iii Appendix Four: Open Source Software Applications in Education 61 References 64 Appendix Five: Mapping the OER Terrain Online 65 Introduction 65 OCW OER Repositories 65 University OCW Initiatives 70 Subject-Specific OCW OER 74 Content Creation Initiatives 78 Open Schooling Initiatives 81 OCW OER Search 84 Conclusion 85 Appendix Six: A Catalogue of OER-Related Websites 87 OCW OER Repositories 88 Open Schooling Initiatives 92 OCW OER Search 93 University OCW Initiatives 95 Subject-Specific OCW-OER 104 OER Tools 109 Other OER Sources 113 Appendix Seven: Some OER Policy Issues in Distance Education 115 Appendix Eight: OER Policy Review Process 123 Appendix Nine: Skills Requirements for Work in Open Educational Resources 13

The influence of gravity upon topology changing transitions and warped flux compactifications

We investigate the dynamics of the geometric transitions associated to compactified spacetimes. By including the effects of gravity we are able to follow the evolution of collapsing cycles as they attempt to undergo a topology changing transition. We perform investigations where we add a perturbation to the momentum of a static solution and observe the consequences this has on the spacetime, looking for evidence of black hole formation or collapsing cycles which could lead to singular geometry. First we look into two possible four dimensional spacelike solutions to the Einstein equations called instantons. These both have a two-sphere at the origin, these are called bolt singularities. We introduce an initial perturbation to reduce the two-sphere to a point. Rather than achieving this singular geometry we find that either a horizon forms, shielding a curvature singularity, or the cycle re-expands after an initial contraction phase. For the case where a horizon forms we identify the final state with a known analytic black-hole solution. In seven dimensions we simulate the gravitational dynamics of the conifold geometries (resolved and deformed) involved in the description of certain compact spacetimes. As the cycles of the conifold collapse towards a singular geometry we inevitably find that a horizon develops, shielding the external spacetime. The structure of the black hole is examined and we find a candidate for the final state of the collapse. In ten dimensions we investigate the time evolution due to gravitational dynamics of a spacetime which is commonly used in brane-cosmology and string compactifications called the Klebanov-Strassler geometry. Here black holes are sometimes formed but more commonly the cycles are seen to re-expand after reaching a minimum value, showing the stability of the solution against perturbations which would change its size

Are the Dorsa Argentea on Mars eskers?

The Dorsa Argentea are an extensive assemblage of ridges in the southern high latitudes of Mars. They have previously been interpreted as eskers formed by deposition of sediment in subglacial meltwater conduits, implying a formerly more extensive south polar ice sheet. In this study, we undertake the first large-scale statistical analysis of aspects of the geometry and morphology of the Dorsa Argentea in comparison with terrestrial eskers in order to evaluate this hypothesis. The ridges are re-mapped using integrated topographic (MOLA) and image (CTX/HRSC) data, and their planar geometries compared to recent characterisations of terrestrial eskers. Quantitative tests for esker-like relationships between ridge height, crest morphology and topography are then completed for four major Dorsa Argentea ridges. The following key conclusions are reached: (1) Statistical distributions of lengths and sinuosities of the Dorsa Argentea are similar to those of terrestrial eskers in Canada. (2) Planar geometries across the Dorsa Argentea support formation of ridges in conduits extending towards the interior of an ice sheet that thinned towards its northern margin, perhaps terminating in a proglacial lake. (3) Variations in ridge crest morphology are consistent with observations of terrestrial eskers. (4) Statistical tests of previously observed relationships between ridge height and longitudinal bed slope, similar to those explained by the physics of meltwater flow through subglacial meltwater conduits for terrestrial eskers, confirm the strength of these relationships for three of four major Dorsa Argentea ridges. (5) The new quantitative characterisations of the Dorsa Argentea may provide useful constraints for parameters in modelling studies of a putative former ice sheet in the south polar regions of Mars, its hydrology, and mechanisms that drove its eventual retreat.FEGB is funded by STFC grant ST/N50421X/1 and is grateful for bursaries provided by The Open University, The Ogden Trust and the British Society for Geomorphology. SJC was funded by a Leverhulme Trust Grant RPG-397. We would like to thank Peter Fawdon for his technical advice. We are grateful to RD Storrar for providing raw data for the Canadian eskers, and to both RD Storrar and H Bernhardt for their insightful reviews of the manuscript.This is the final version of the article. It first appeared from Elsevier via https://doi.org/ 10.1016/j.icarus.2016.03.02

Guía básica de Recursos Educativos Abiertos (REA)

Esta Guía comprende tres secciones. La primera – un resumen de los asuntos clave – se presenta bajo la forma de un conjunto de “Preguntas Frecuentes”. Su objetivo es proporcionar al lector una introducción rápida y de fácil Utilización a los Recursos Educativos Abiertos (REA) y a los asuntos clave que deben considerarse al buscar la manera más eficaz de utilizar los REA. La segunda sección contiene un análisis más extenso de esos asuntos, los cuales se presentan bajo la forma de un artículo tradicional de investigación. Para los que estén interesados en estudiar más a fondo los REA, la sección servirá como auxilio para defender la causa de los REA con mayores fundamentos. La tercera sección constituye un conjunto de apéndices, los cuales contienen información más detallada sobre áreas específicas relevantes para los REA. Dichos apéndices se destinan a personas que estén buscando información fidedigna sobre cualquier área de interés específica

Genome Environment Browser (GEB): a dynamic browser for visualising high-throughput experimental data in the context of genome features

<p>Abstract</p> <p>Background</p> <p>There is accumulating evidence that the milieu of repeat elements and other non-genic sequence features at a given chromosomal locus, here defined as the genome environment, can play an important role in regulating chromosomal processes such as transcription, replication and recombination. The availability of whole-genome sequences has allowed us to annotate the genome environment of any locus in detail. The development of genome wide experimental analyses of gene expression, chromatin modification and chromatin proteins means that it is now possible to identify potential links between chromosomal processes and the underlying genome environment. There is a need for novel bioinformatic tools that facilitate these studies.</p> <p>Results</p> <p>We developed the Genome Environment Browser (GEB) in order to visualise the integration of experimental data from large scale high throughput analyses with repeat sequence features that define the local genome environment. The browser has incorporated dynamic scales adjustable in real-time, which enables scanning of large regions of the genome as well as detailed investigation of local regions on the same page without the need to load new pages. The interface also accommodates a 2-dimensional display of repetitive features which vary substantially in size, such as LINE-1 repeats. Specific queries for preliminary quantitative analysis of genome features can also be formulated, results of which can be exported for further analysis.</p> <p>Conclusion</p> <p>The Genome Environment Browser is a versatile program which can be easily adapted for displaying all types of genome data with known genomic coordinates. It is currently available at <url>http://web.bioinformatics.ic.ac.uk/geb/</url>.</p

Artificial intelligence capacity in Sub-Saharan Africa : compendium report

Artificial Intelligence for Development (AI4D) Africa supported research on three key stakeholders involved in AI capacity building in sub-Saharan Africa (SSA): Centres of Higher Education and Training; Governments; and the broader AI community in the region. A comprehensive desktop literature review was also conducted. Taking available data into account together with the desktop review of literature and the findings from the UNESCO report, this detailed paper provides takeaways from the research. In line with the recommendations presented here, the key to creating a vibrant AI ecosystem is committed stakeholder engagement that pushes individual countries forward by building capacity in key areas