Is spatial intelligibility critical to the design of largescale virtual environments?

This paper discusses the concept of 'intelligibility', a concept usually attributed to the design of real-world environments and suggests how it might be applied to the construction of virtual environments. In order to illustrate this concept, a 3d, online, collaborative environment, AlphaWorld, is analyzed in a manner analogous to spatial analysis techniques applied to cities in the real world. The outcome of this form of spatial analysis is that AlphaWorld appears to be highly 'intelligible' at the small-scale, 'local neighborhood' level, and yet is completely 'unintelligible' at a global level. This paper concludes with a discussion of the relevance of this finding to virtual environment design plus future research applications

Social exclusion and transportation in Peachtree City, Georgia

This paper will discuss how, in a small American city, Peachtree City (43km south of Atlanta), the flexibility and relative affordability of electric golf carts, as a viablealternative to the automobile, means that the level at which families and individuals are disadvantaged through their lack of access to public/private transport is effectively lowered. Economic access to golf carts, in of itself, would not be sufficient if it were not for the extensive, highly penetrative and ‘ringy’ spatial structure of the cart path system, a mostly-segregated, 150 kilometre network. A spatial analysis of this dual transportation system is presented and its implications discussed. The conclusion of this paper is that the duality of the effective spatial structure of the cart path networkand the relative low cost and inherent flexibility of the golf carts combine to reduce transportation-linked social exclusion in Peachtree City. This argument is substantiated, in the final section of the paper, through the evidence of a questionnairedistributed to a random sampling of 1,038 property owners and renters in the city

An Overview of Leber’s Hereditary Optic Neuropathy

Typically affecting males ranging from 20 to 24 years of age, Leber’s Hereditary Optic Neuropathy (LHON) is a disorder that is characterized by an acute loss of central vision. Although a heritable disease, LHON does not follow the patterns of classical Mendelian genetics. In fact, one of the most striking characteristics of LHON is that the disease is virtually always inherited maternally. Unlike most genetic disorders that result from a mutation in genomic DNA, LHON is caused by a mutation in the genetic information of mitochondria (mtDNA). Currently there is no treatment for LHON. Despite this, pharmaceutical interventions and contemporary treatment methods, such as gene therapy, are beginning to show promise

Path, theme and narrative in open plan exhibition settings

Three arguments are made based on the analysis of science exhibitions. First,sufficiently refined techniques of spatial analysis allow us to model the impact oflayout upon visitors' paths, even in moderately sized open plans which allow almostrandom patterns of movement and relatively unobstructed visibility. Second, newlydeveloped or adapted techniques of analysis allow us to make a transition frommodeling the mechanics of spatial movement (the way in which movement is affectedby the distribution of obstacles and boundaries), to modeling the manner in whichmovement might register additional aspects of visual information. Third, theadvantages of such purely spatial modes of analysis extend into providing us with asharper understanding of some of the pragmatic constrains within which exhibitioncontent is conceived and designed

Teaching space syntax through reflective practice and practica

22-23 July 200

Homologous Recombination under the Single-Molecule Fluorescence Microscope

Homologous recombination (HR) is a complex biological process and is central to meiosis and for repair of DNA double-strand breaks. Although the HR process has been the subject of intensive study for more than three decades, the complex protein–protein and protein–DNA interactions during HR present a significant challenge for determining the molecular mechanism(s) of the process. This knowledge gap is largely because of the dynamic interactions between HR proteins and DNA which is difficult to capture by routine biochemical or structural biology methods. In recent years, single-molecule fluorescence microscopy has been a popular method in the field of HR to visualize these complex and dynamic interactions at high spatiotemporal resolution, revealing mechanistic insights of the process. In this review, we describe recent efforts that employ single-molecule fluorescence microscopy to investigate protein–protein and protein–DNA interactions operating on three key DNA-substrates: single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), and four-way DNA called Holliday junction (HJ). We also outline the technological advances and several key insights revealed by these studies in terms of protein assembly on these DNA substrates and highlight the foreseeable promise of single-molecule fluorescence microscopy in advancing our understanding of homologous recombination