Dynamic multimedia content access in a ubiquitous and distributed computing environment

Ubiquitous computing is the concept of embedding many heterogeneous devices within our everyday environment in such a way that they operate seamlessly and become transparent to the person using them. It covers a wide range of applications and services, but of particular interest is multimedia resource adaptation which involves customization and dynamic adaptation of resources according to usage environments and user preferences; this aims to provide consumers with transparent access. This thesis proposes a content negotiation architecture for dynamic adaptation of multimedia content according to usage environment attributes. The architecture shields users from complex configuration details related to the adaptation of multimedia content, while guiding them through user related choices. The architecture also dynamically updates the multimedia content during transmission and consumption when related usage environment attributes are changed. The content negotiation mechanism in the proposed architecture is then extended and deployed in a mobile computing environment to accommodate transfer of multimedia content application session state between devices in a seamless manner. An application session transfer architecture which allows sessions to be directed, stored and transferred through an intermediary session server is proposed. The thesis also considers the foregoing work on the adaptation of multimedia resources applied to sharing in a Peer-to-Peer (P2P) network. It proposes a super peer based dynamic resource adaptation architecture which employs \u27pull\u27 and \u27push\u27 two-stage adaptation approach. This guides users through resource search and configuration details without exposing them to unnecessary technical details; the result is that requested content is transparently adapted to heterogeneous terminal devices. Two separate, but related, modifications are proposed to further improve the performance of the proposed P2P architecture. Firstly, peers are clustered according to registered geographic location information and secondly, based on that registered location information, a locality-based service is introduced which allows users to search services according to their geographic locations. The latter encourages service providers to increase the uptime of their devices and hence provide spare computing power for active adaptation of resources for low-end peers. Resource replication is an important aspect of a P2P system and an adaptive resource replication strategy based on the proposed P2P architecture is presented. It uses resource request rate as the metric to trigger the resource replication process, and proportionally replicates multimedia resources into various configuration states according to the properties of peers and the size of peer clusters. Also, the strategy uses peer related information stored on super peers to determine which peers should be selected to perform adaptive replications and where the resulting replicas should be stored. The proposed adaptive replication strategy demonstrates that the network delays are reduced while resource hit rate is increased in comparison to other replication strategies. Investigation of the deployment of a BitTorrent (BT) - like approach in the proposed P2P resource adaptation architecture is also considered in this thesis. In addition, the architecture\u27s peer selection strategy is adopted and evaluated as a way to enhance the peer selection process in BT. The strategy uses super peers as trackers to intelligently select peers according to their capabilities and shared resource segments and overcome the scalability issue of existing BT implementation. The proposed selection strategy reduces average access time and increases download speed when compared with the existing BT peer selection process with randomly selected peers. Also, the deployment of BT in the proposed P2P architecture shows that it greatly reduces the congested download problem which was previously reported

Intrinsically Disordered C-Terminal Tails of \u3cem\u3eE. coli\u3c/em\u3e Single-Stranded DNA Binding Protein Regulate Cooperative Binding to Single-Stranded DNA

The homotetrameric Escherichia coli single-stranded DNA binding protein (SSB) plays a central role in DNA replication, repair and recombination. E. coli SSB can bind to long single-stranded DNA (ssDNA) in multiple binding modes using all four subunits [(SSB)65 mode] or only two subunits [(SSB)35 binding mode], with the binding mode preference regulated by salt concentration and SSB binding density. These binding modes display very different ssDNA binding properties with the (SSB)35 mode displaying highly cooperative binding to ssDNA. SSB tetramers also bind an array of partner proteins, recruiting them to their sites of action. This is achieved through interactions with the last 9 amino acids (acidic tip) of the intrinsically disordered linkers (IDLs) within the four C-terminal tails connected to the ssDNA binding domains. Here, we show that the amino acid composition and length of the IDL affects the ssDNA binding mode preferences of SSB protein. Surprisingly, the number of IDLs and the lengths of individual IDLs together with the acidic tip contribute to highly cooperative binding in the (SSB)35 binding mode. Hydrodynamic studies and atomistic simulations suggest that the E. coli SSB IDLs show a preference for forming an ensemble of globular conformations, whereas the IDL from Plasmodium falciparum SSB forms an ensemble of more extended random coils. The more globular conformations correlate with cooperative binding

Design and development of a theory-informed peer-led falls prevention education programme to translate evidence into practice: A systematic approach

Peer-led education has been shown to be an effective approach for raising community-dwelling older adults’ beliefs, knowledge and intention to engage in falls prevention strategies in a recent intervention trial. This article outlines the design and development of the intervention, which was a peer-led falls prevention education programme designed to promote older adult’s motivation to change their behaviour in the area of falls prevention. The elements of the programme that contributed to its efficacy are also described. The programme was designed using a four-step approach and was based on the constructs of a theoretical framework (the COM-B model). Feedback from older adults was also incorporated into the programme development. Programme components developed were a workshop to train older adult peer educators to deliver falls prevention education, a one-hour peer-led falls prevention presentation, and supporting resources to aid programme delivery. A questionnaire measuring older adults’ responses to the presentation was concurrently developed and pilot-tested prior to implementation of the education programme. Finally, resources to monitor and evaluate fidelity at five points in the programme were developed. It was found that seeking older adult consumer involvement, and adopting a theoretical framework-driven approach contributes to effective design and delivery of falls prevention education programmes. This ensured that the programme was acceptable to older adults, feasible to deliver and allowed robust measurement of the effect of the education programme on important behavioural change components

Open Letter on Ethical Norms in Intellectual Property Scholarship

As scholars who write in intellectual property (“IP”), we write this letter with aspirations of reaching the highest ethical norms possible for our field. In particular, we have noted an influx of large contributions from corporate and private actors who have an economic stake in ongoing policy debates in the field. Some dollars come with strings attached, such as the ability to see or approve academic work prior to publication or limitations on the release of data. IP scholars who are also engaged in practice or advocacy must struggle to keep their academic and advocacy roles separate.Our goal is to bring attention to the dramatic changes that are occurring in the field, highlight the potential pitfalls, and suggest a set of ethical norms to which we will strive to adhere. We conclude this letter with a set of ethical norms to which a large number of IP academics have already subscribed. We welcome additional signatories to the principles expressed in this letter