Collaborative Mapping of London Using Google Maps: The LondonProfiler

This paper begins by reviewing the ways in which the innovation of Google Maps has transformed our ability to reference and view geographically referenced data. We describe the ways in which the GMap Creator tool developed under the ESRC National Centre for E Social Science programme enables users to ‘mashup’ thematic choropleth maps using the Google API. We illustrate the application of GMap Creator using the example of www.londonprofiler.org, which makes it possible to view a range of health, education and other socioeconomic datasets against a backcloth of Google Maps data. Our conclusions address the ways in which Google Map mashups developed using GMap Creator facilitate online exploratory cartographic visualisation in a range of areas of policy concern

Orbispaces and their Mapping Spaces via Groupoids: A Categorical Approach

In this paper, we give an accessible introduction to the theory of orbispaces via groupoids. We define a certain class of topological groupoids, which we call orbigroupoids. Each orbigroupoid represents an orbispace, but just as with orbifolds and Lie groupoids, this representation is not unique: orbispaces are Morita equivalence classes of orbigroupoids. We show how to formalize this equivalence by defining the category of orbispaces as a bicatecory of fractions from the category of orbigroupoids. We focus particularly on laying the groundwork for future work in creating mapping objects for orbispaces which are themselves orbispaces, and providing a concrete description of how this mapping space construction will get its orbispace structure. Throughout this paper, we illustrate our definitions and results with numerous examples which we hope will be useful in seeing how the categorical point of view is used to study these spaces

The Golgin GMAP-210

The protein GMAP-210 (Golgi Microtubule Associated Protein of 210 kDa) is a long coiled-coil protein, which localises to the Golgi apparatus. It is part of the loosely defined protein group of the golgins, which are involved in establishing the Golgi morphology and in vesicular trafficking around the Golgi. By using biochemical, cell biological and molecular biological methods GMAP-210 was examined in regards to its Golgi targeting capability, its interaction partners and its function in establishing Golgi morphology and positioning. In vitro and in vivo experiments showed that GMAP-210 targets to the Golgi via its C-terminal GRAB domain. Its proposed interaction with Arf1, however, could not be definitely determined, although there is strong evidence for it. Arf1 binding to the GRAB domain was hindered in the full-length protein, but not with short C-terminal fragments containing the minimal GRAB domain. This implies that additional factors are needed for GMAP-210 Golgi binding. A yeast 2-hybrid screen of the entire family of small Rab GTPases identified the Golgi and ER localised Rab1 as a novel interaction partner of GMAP-210. GMAP-210 also labels vesicular tubular structures in the cell, which partially overlap with COPII and ERGIC53, components of the early secretory pathway. This gives additional evidence that GMAP- 210 is involved in ER to Golgi transport. Trafficking of a model substrate, the vesicular stomatitis virus G-protein (VSV-G), however, was not impaired in the absence of GMAP- 210. This indicates that GMAP-210 functions only in specialised transport pathways. Knockdown of GMAP-210 in HeLa L cells by siRNA changed the Golgi morphology and the Golgi fragmented into a cluster of vesicles. Its overexpression caused the Golgi to grow long tubular structures. Both effects on morphology could only be observed in HeLa L cells, not in hTERT-RPE1 cells. As direct interaction with microtubules or γ-tubulin could not be detected, and GMAP-210 is therefore unlikely to affect Golgi morphology by directly perturbing microtubule function. GMAP-210 knockdown by siRNA also showed its interaction with the intraflagellar transport protein IFT20. This protein lost its Golgi localisation when GMAP-210 was depleted. Both proteins interacted directly. GMAP-210, however, was not involved in primary cilium formation in hTERT-RPE1 cells and loss of IFT20 from the Golgi did not impair formation of the cilium, proposing that the Golgi pool of IFT20 had a function apart from intraflagellar transport and formation of the primary cilium. These results set GMAP-210 apart from the archetypal golgins GM130 and p115 and indicate that GMAP-210 is involved in a highly specialised transport pathway, which could nevertheless influence the morphology of the Golgi apparatus in certain cell types

D-modules on Spaces of Rational Maps and on other Generic Data

Let X be an algebraic curve. We study the problem of parametrizing geometric data over X, which is only generically defined. E.g., parametrizing generically defined (aka rational) maps from X to a fixed target scheme Y. There are three methods for constructing functors of points for such moduli problems (all originally due to Drinfeld), and we show that the resulting functors are equivalent in the fppf Grothendieck topology. As an application, we obtain three presentations for the category of D-modules "on" B (K) \G (A) /G (O), and we combine results about this category coming from the different presentations.Comment: 55 page

Removal and Contraction Operations in nnD Generalized Maps for Efficient Homology Computation

In this paper, we show that contraction operations preserve the homology of $n$D generalized maps, under some conditions. Removal and contraction operations are used to propose an efficient algorithm that compute homology generators of $n$D generalized maps. Its principle consists in simplifying a generalized map as much as possible by using removal and contraction operations. We obtain a generalized map having the same homology than the initial one, while the number of cells decreased significantly. Keywords: $n$D Generalized Maps; Cellular Homology; Homology Generators; Contraction and Removal Operations.Comment: Research repor

Induction of Topological Environment Maps from Sequences of Visited Places

In this paper we address the problem of topologically mapping environments which contain inherent perceptual aliasing caused by repeated environment structures. We propose an approach that does not use motion or odometric information but only a sequence of deterministic measurements observed by traversing an environment. Our algorithm implements a stochastic local search to build a small map which is consistent with local adjacency information extracted from a sequence of observations. Moreover, local adjacency information is incorporated to disambiguate places which are physically different but appear identical to the robots senses. Experiments show that the proposed method is capable of mapping environments with a high degree of perceptual aliasing, and that it infers a small map quickly