A novel mode of nuclease action is revealed by the bacterial Mre11/Rad50 complex

The Mre11/Rad50 complex is a central player in various genome maintenance pathways. Here, we report a novel mode of nuclease action found for the Escherichia coli Mre11/Rad50 complex, SbcC(2)/D(2) complex (SbcCD). SbcCD cuts off the top of a cruciform DNA by making incisions on both strands and continues cleaving the dsDNA stem at ∼10-bp intervals. Using linear-shaped DNA substrates, we observed that SbcCD cleaved dsDNA using this activity when the substrate was 110 bp long, but that on shorter substrates the cutting pattern was changed to that predicted for the activity of a 3′-5′ exonuclease. Our results suggest that SbcCD processes hairpin and linear dsDNA ends with this novel DNA end-dependent binary endonuclease activity in response to substrate length rather than using previously reported activities. We propose a model for this mode of nuclease action, which provides new insight into SbcCD activity at a dsDNA end

Managing geography learning objects using personalized project spaces in G-Portal

8 page(s

Supporting field study with personalized project spaces in a geographical digital library

10 page(s

Managing media rich geo-spatial annotations for a map-based mobile application using clustering

The world has still to emerge fully from the housing-triggered Global Financial Crisis, but housing crises are not new. The history of housing shows long-run social progress, littered with major disasters; nevertheless the progress is often forgotten, whilst the difficulties hit the headlines. Housing Economics provides a long-term economic perspective on macro and urban housing issues, from the Victorian era onwards. A historical perspective sheds light on modern problems and the constraints on what can be achieved; it concentrates on the key policy issues of housing supply, affordability, tenure, the distribution of migrant communities, mortgage markets and household mobility. Local case studies are interwoven with city-wide aggregate analysis. Three sets of issues are addressed: the underlying reasons for the initial establishment of residential neighbourhoods, the processes that generate growth, decline and patterns of integration/segregation, and the impact of historical development on current problems and the implications for policy

Tagnsearch: Searching and navigating geo-referenced collections of photographs

A*STAR gran

Integration of Wikipedia and a Geography Digital Library

In this paper, we address the problem of integrating Wikipedia, an online encyclopedia, and G-Portal, a web-based digital library, in the geography domain. The integration facilitates the sharing of data and services between the two web applications that are of great value in learning. We first present an overall system architecture for supporting such an integration and address the metadata extraction problem associated with it. In metadata extraction, we focus on extracting and constructing metadata for geo-political regions namely cities and countries. Some empirical performance results will be presented. The paper will also describe the adaptations of G-Portal and Wikipedia to meet the integration requirements.Accepted versio

Understanding user perceptions on usefulness and usability of an integrated Wiki-G-Portal

This paper describes briefly the design rationale and philosophy of our implementation of a Wiki-G-Portal project, integrating Wikipedia, an online encyclopedia, into G-Portal, a Web-based digital library, of geography resources. Initial findings from pilot study seemed to suggest positive perceptions on usefulness and usability of Wiki-G-Portal, as well as subjects’ attitude and intention to use Wiki-G-Portal. The paper concludes with recommendations for further work.Accepted versio

Sharing mobile multimedia annotations to support inquiry-based learning using Mobitop

A*STAR5820/2009</p