2,799 research outputs found

    Division of labour and sharing of knowledge for synchronous collaborative information retrieval

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    Synchronous collaborative information retrieval (SCIR) is concerned with supporting two or more users who search together at the same time in order to satisfy a shared information need. SCIR systems represent a paradigmatic shift in the way we view information retrieval, moving from an individual to a group process and as such the development of novel IR techniques is needed to support this. In this article we present what we believe are two key concepts for the development of effective SCIR namely division of labour (DoL) and sharing of knowledge (SoK). Together these concepts enable coordinated SCIR such that redundancy across group members is reduced whilst enabling each group member to benefit from the discoveries of their collaborators. In this article we outline techniques from state-of-the-art SCIR systems which support these two concepts, primarily through the provision of awareness widgets. We then outline some of our own work into system-mediated techniques for division of labour and sharing of knowledge in SCIR. Finally we conclude with a discussion on some possible future trends for these two coordination techniques

    Dose-dependent protection of reseveratrol against spinal cord ischemic-reperfusion injury in rats

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    Purpose: To examine the protective effects of resveratrol (RESV) against spinal cord ischemic reperfusion (SCIR) injury.Methods: Forty-eight male rats were divided into six groups: sham-operated (control-I), SCIR-treated (SCIR-II), rats receiving 20 mg/kg of RESV with SCIR (RESV 20+SCIR-III), rats receiving 40 mg/kg of RESV with SCIR (RESV  40+SCIR-IV), rats receiving 60 mg/kg of RESV with SCIR (RESV 60+SCIR-V), and rats receiving 50 mg/kg of methylprednisolone (MP) with SCIR (MP + SCIR-VI), for 7 days prior to IR (pre-treatment) and 7 days after IR (post-treatment).Results: The levels of oxidative markers (TBARS, MPO) and inflammatory markers (IL-1β, IL-6, TNF-α, and NF-p65) were concomitantly suppressed in RESV-treated rats, which showed improved locomotor function. A pronounced increase in the activities of antioxidant enzymes (SOD, CAT and GSH) was noted in the RESV group compared with the MP and SCIR groups. RESV and MP supplementation increased neuronal count with decreased nuclear degeneration. RESV (40 mg) exhibited  greater protective effect than 20 mg and 60 mg of RESV and 50 mg of MP.Conclusion: The results show the neurotherapeutic potential of RESV (40 mg) to attenuate oxidative stress and the inflammatory response to SCIR injury.Keywords: Spinal cord ischemia reperfusion, Resveratrol, Locomotor function,  Antioxidant, Inflammatory marker

    Synchronous collaborative information retrieval: techniques and evaluation

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    Synchronous Collaborative Information Retrieval refers to systems that support multiple users searching together at the same time in order to satisfy a shared information need. To date most SCIR systems have focussed on providing various awareness tools in order to enable collaborating users to coordinate the search task. However, requiring users to both search and coordinate the group activity may prove too demanding. On the other hand without effective coordination policies the group search may not be effective. In this paper we propose and evaluate novel system-mediated techniques for coordinating a group search. These techniques allow for an effective division of labour across the group whereby each group member can explore a subset of the search space.We also propose and evaluate techniques to support automated sharing of knowledge across searchers in SCIR, through novel collaborative and complementary relevance feedback techniques. In order to evaluate these techniques, we propose a framework for SCIR evaluation based on simulations. To populate these simulations we extract data from TREC interactive search logs. This work represent the first simulations of SCIR to date and the first such use of this TREC data

    Combining relevance information in a synchronous collaborative information retrieval environment

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    Traditionally information retrieval (IR) research has focussed on a single user interaction modality, where a user searches to satisfy an information need. Recent advances in both web technologies, such as the sociable web of Web 2.0, and computer hardware, such as tabletop interface devices, have enabled multiple users to collaborate on many computer-related tasks. Due to these advances there is an increasing need to support two or more users searching together at the same time, in order to satisfy a shared information need, which we refer to as Synchronous Collaborative Information Retrieval. Synchronous Collaborative Information Retrieval (SCIR) represents a significant paradigmatic shift from traditional IR systems. In order to support an effective SCIR search, new techniques are required to coordinate users' activities. In this chapter we explore the effectiveness of a sharing of knowledge policy on a collaborating group. Sharing of knowledge refers to the process of passing relevance information across users, if one user finds items of relevance to the search task then the group should benefit in the form of improved ranked lists returned to each searcher. In order to evaluate the proposed techniques we simulate two users searching together through an incremental feedback system. The simulation assumes that users decide on an initial query with which to begin the collaborative search and proceed through the search by providing relevance judgments to the system and receiving a new ranked list. In order to populate these simulations we extract data from the interaction logs of various experimental IR systems from previous Text REtrieval Conference (TREC) workshops

    Why Quantum Theory is Possibly Wrong

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    Quantum theory is a tremendously successful physical theory, but nevertheless suffers from two serious problems: the measurement problem and the problem of interpretational underdetermination. The latter, however, is largely overlooked as a genuine problem of its own. Both problems concern the doctrine of realism, but pull, quite curiously, into opposite directions. The measurement problem can be captured such that due to scientific realism about quantum theory common sense anti-realism follows, while theory underdetermination usually counts as an argument against scientific realism. I will also consider the more refined distinctions of ontic and epistemic realism and demonstrate that quantum theory in its most viable interpretations conflicts with at least one of the various realism claims. A way out of the conundrum is to come to the bold conclusion that quantum theory is, possibly, wrong (in the realist sense)

    On the occurrence of oscillatory modulations in the power-law behavior of dynamic and kinetic processes in fractals

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    The dynamic and kinetic behavior of processes occurring in fractals with spatial discrete scale invariance (DSI) is considered. Spatial DSI implies the existence of a fundamental scaling ratio (b_1). We address time-dependent physical processes, which as a consequence of the time evolution develop a characteristic length of the form ξt1/z\xi \propto t^{1/z}, where z is the dynamic exponent. So, we conjecture that the interplay between the physical process and the symmetry properties of the fractal leads to the occurrence of time DSI evidenced by soft log-periodic modulations of physical observables, with a fundamental time scaling ratio given by τ=b1z\tau = b_1 ^z. The conjecture is tested numerically for random walks, and representative systems of broad universality classes in the fields of irreversible and equilibrium critical phenomena.Comment: 6 pages, 3 figures. Submitted to EP

    Can graph-cutting improve microarray gene expression reconstructions?

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    Microarrays produce high-resolution image data that are, unfortunately, permeated with a great deal of “noise” that must be removed for precision purposes. This paper presents a technique for such a removal process. On completion of this non-trivial task, a new surface (devoid of gene spots) is subtracted from the original to render more precise gene expressions. The graph-cutting technique as implemented has the benefits that only the most appropriate pixels are replaced and these replacements are replicates rather than estimates. This means the influence of outliers and other artifacts are handled more appropriately (than in previous methods) as well as the variability of the final gene expressions being considerably reduced. Experiments are carried out to test the technique against commercial and previously researched reconstruction methods. Final results show that the graph-cutting inspired identification mechanism has a positive significant impact on reconstruction accuracy
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