84 research outputs found

    Feasibility and performance analysis of middleware support for a situated virtual-physical civic engagement platform

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    Abstract. With the prevalent ubiquitous computing technologies, it is possible to explore novel solutions for supporting civic engagement as a set of urban practices. One interesting urban practice is the soapbox, traditionally conceived as wooden structure, from where to hold impromptu speeches. For this thesis, a novel soapbox prototype with ubiquitous computing mediated technologies is introduced, with our focus on the feasibility and performance analysis of its middleware support, investigating how our middleware is able to meet the goals of a situated virtual-physical civic engagement platform. Based on our empirical evaluations, it is demonstrated that our prototype is effective to support civic engagement and serve purpose of continuously soapbox streaming

    The Dkk3 gene encodes a vital intracellular regulator of cell proliferation

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    Members of the Dickkopf (Dkk) family of Wnt antagonists interrupt Wnt-induced receptor assembly and participate in axial patterning and cell fate determination. One family member, DKK3, does not block Wnt receptor activation. Loss of Dkk3 expression in cancer is associated with hyperproliferation and dysregulated ss-catenin signaling, and ectopic expression of Dkk3 halts cancer growth. The molecular events mediating the DKK3-dependent arrest of ss-catenin-driven cell proliferation in cancer cells are unknown. Here we report the identification of a new intracellular gene product originating from the Dkk3 locus. This Dkk3b transcript originates from a second transcriptional start site located in intron 2 of the Dkk3 gene. It is essential for early mouse development and is a newly recognized regulator of ss-catenin signaling and cell proliferation. Dkk3b interrupts nuclear translocation ss-catenin by capturing cytoplasmic, unphosphorylated ss-catenin in an extra-nuclear complex with ss-TrCP. These data reveal a new regulator of one of the most studied signal transduction pathways in metazoans and provides a novel, completely untapped therapeutic target for silencing the aberrant ss-catenin signaling that drives hyperproliferation in many cancers

    Role of retinoid receptor coactivator pockets in cofactor recruitment and transcriptional regulation

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    The nuclear receptor for retinoic acid (RAR) forms a heterodimeric complex with the retinoid X receptor (RXR). This RXR/RAR heterodimer binds to the promoter of retinoic acid target genes and recruits coactivators and corepressors to regulate gene expression. Currently, the relative role of each receptor monomer in regulating coactivator and corepressor recruitment remains unclear. Here we show that the receptor-associated coactivator 3 (RAC3) uses two separate LXXLL motifs to bind RAR and RXR. The mutation of the coactivator-binding pockets of RAR and RXR abolishes RAC3 binding. Although the coactivator pocket of RXR is essential for the function of the RXR homodimer, it has a minor role for the recruitment of RAC3 and trans-activation by the RXR/RAR heterodimer. Consistently, deletion of the activation helix of RXR enhances binding of RAC3 to the heterodimer, and mutation of the coactivator pocket of RXR had little effect on RXR/RAR activity. In contrast, the coactivator pocket and the activation helix of RAR are absolutely required. We also show that different residues of the RAR coactivator pocket are used differently for interactions with the corepressor silencing mediator for retinoid and thyroid hormone receptor (SMRT) and coactivator. These results indicate a differential role for each retinoid receptor to the overall binding of cofactors and regulation of transcription by the retinoid receptor heterodimer

    Soapbox:a situated platform for civic engagement

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    Abstract This paper presents an interactive Soapbox platform, which utilizes networked public displays to encourage local citizens to participate in civic engagement. Soapbox is comprised of three subsystems: Soapbox for speaker (SFS), Soapbox for audience (SFA) and Shoutbox. SFS allows people to deliver a speech to the public. SFA enables audience members to watch a speech and give feedback to it. Shoutbox is an input tool that runs on personal devices and is used to author comments and share them with the speaker and other members of the audience. The Soapbox system was evaluated in both the lab and the field. The evaluation demonstrated that users are positive about trying the platform, and can quickly grasp how to use it. Further, participants thought that Soapbox is very appropriate for its purpose, and can effectively attract more citizens to participate in civic engagement

    Enabling user-centered interactions in the internet of things

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    Abstract We introduce a novel interaction method which integrates humans into Internet of Things and advances from the existing client-server paradigm. We take advantage of the shared physical space to facilitate decentralized and seamless human-to-thing, human-to-human and thing-to-thing interactions. We build these interactions upon two core technologies: mobile agents and NFC. Mobile agents realize autonomous execution of user-specific interaction tasks among things while facilitating cooperation and interoperability. Humans initiate and control interactions through physical actions that trigger communications, e.g. mobile agent migration, between NFC devices even over disparate systems. Human social relationships are utilized to disseminate tasks further in the IoT system. We discuss the benefits of this method in comparison with the common smartphone-based control of smart spaces. Real-world evaluation shows that this interaction method is feasible for resource-constrained embedded IoT devices

    Risk-aware path selection with time-varying, uncertain travel costs: a time series approach

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    We address the problem of choosing the best paths among a set of candidate paths between the same origin–destination pair. This functionality is used extensively when constructing origin–destination matrices in logistics and flex transportation. Because the cost of a path, e.g., travel time, varies over time and is uncertain, there is generally no single best path. We partition time into intervals and represent the cost of a path during an interval as a random variable, resulting in an uncertain time series for each path. When facing uncertainties, users generally have different risk preferences, e.g., risk-loving or risk-averse, and thus prefer different paths. We develop techniques that, for each time interval, are able to find paths with non-dominated lowest costs while taking the users’ risk preferences into account. We represent risk by means of utility function categories and show how the use of first-order and two kinds of second-order stochastic dominance relationships among random variables makes it possible to find all paths with non-dominated lowest costs. We report on empirical studies with large uncertain time series collections derived from a 2-year GPS data set. The study offers insight into the performance of the proposed techniques, and it indicates that the best techniques combine to offer an efficient and robust solution.</p
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