41,034 research outputs found

    Sensory semantic user interfaces (SenSUI)

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    Rapid evolution of the World Wide Web with its underlying sources of data, knowledge, services and applications continually attempts to support a variety of users, with different backgrounds, requirements and capabilities. In such an environment, it is highly unlikely that a single user interface will prevail and be able to fulfill the requirements of each user adequately. Adaptive user interfaces are able to adapt information and application functionalities to the user context. In contrast, pervasive computing and sensor networks open new opportunities for context aware platforms, one that is able to improve user interface adaptation reacting to environmental and user sensors. Semantic web technologies and ontologies are able to capture sensor data and provide contextual information about the user, their actions, required applications and environment. This paper investigates the viability of an approach where semantic web technologies are used to maximize the efficacy of interface adaptation through the use of available ontology

    High-Spatial Resolution Laser Doppler Blood Flow Imaging

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    This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.A full-field laser Doppler blood flow imaging (LDI) system based on an FPGA (Field Programmable Gate Array) coupled with a high-speed CMOS (Complementary Metal-Oxide-Semiconductor) camera chip has been developed which provides blood flow images with flexible frame rates and spatial resolution. When a high spatial resolution is required, 1280x1024-pixel blood flow images were obtained by processing up to 2048 samples at 0.2 frames per second (fps). Alternatively, a maximum of 15.5fps was achieved by reducing the spatial resolution and sampling points to 256x256 pixels and 128 samples respectively. This system was applied to a high-spatial resolution flow imaging application in which a mixture of water and polystyrene microspheres was pumped through a micropipette (diameter = 250m) with controlled velocities, and the resulting flow was imaged and processed. The performance was demonstrated by the resulting flow images which are of size 1280×1024 pixels and obtained by processing 2048 samples at each pixel

    C IV BAL disappearance in a large SDSS QSO sample

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    Broad absorption lines (BALs) in the spectra of quasi-stellar objects (QSOs) originate from outflowing winds along our line of sight; winds are thought to originate from the inner regions of the QSO accretion disk, close to the central supermassive black hole (SMBH). Winds likely play a role in galaxy evolution and aid the accretion mechanism onto the SMBH. BAL equivalent widths can change on typical timescales from months to years; such variability is generally attributed to changes in the covering factor and/or in the ionization level of the gas. We investigate BAL variability, focusing on BAL disappearance. We analyze multi-epoch spectra of more than 1500 QSOs -the largest sample ever used for such a study- observed by different programs from the Sloan Digital Sky Survey-I/II/III (SDSS), and search for disappearing C IV BALs. The spectra rest-frame time baseline ranges from 0.28 to 4.9 yr; the source redshifts range from 1.68 to 4.27. We detect 73 disappearing BALs in the spectra of 67 sources. This corresponds to 3.9% of disappearing BALs, and 5.1% of our BAL QSOs exhibit at least one disappearing BAL. We estimate the average lifetime of a BAL along our line of sight (~ 80-100 yr), which appears consistent with the accretion disk orbital time at distances where winds are thought to originate. We inspect properties of the disappearing BALs and compare them to the properties of our main sample. We also investigate the existence of a correlation in the variability of multiple troughs in the same spectrum, and find it persistent at large velocity offsets between BAL pairs, suggesting that a mechanism extending on a global scale is necessary to explain the phenomenon. We select a more reliable sample of disappearing BALs following Filiz Ak et al. (2012), where a subset of our sample was analyzed, and compare the findings from the two works, obtaining generally consistent results.Comment: 22 pages, 9 figures. Accepted for publication in A&

    A major T cell antigen of Mycobacterium leprae is a 10-kD heat-shock cognate protein.

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    Several mycobacterial antigens, identified by monoclonal antibodies and patient sera, have been found to be homologous to stress or heat-shock proteins (hsp) defined in Escherichia coli and yeast. A major antigen recognized by most Mycobacterium leprae-reactive human T cell lines and cell wall-reactive T cell clones is a 10-kD protein that has now been cloned and sequenced. The predicted amino acid sequence of this protein is 44% homologous to the hsp 10 (GroES) of E. coli. The purified native and recombinant 10-kD protein was found to be a stronger stimulator of peripheral blood T cell proliferation than other native and recombinant M. leprae proteins tested. The degree of reactivity paralleled the response to intact M. leprae throughout the spectrum of leprosy. Limiting-dilution analysis of peripheral blood lymphocytes from a patient contact and a tuberculoid patient indicated that approximately one third of M. leprae-reactive T cell precursors responded to the 10-kD antigen. T cell lines derived from lepromin skin tests were strongly responsive to the 10-kD protein. T cell clones reactive to both the purified native and recombinant 10-kD antigens recognized M. leprae-specific epitopes as well as epitopes crossreactive with the cognate antigen of M. tuberculosis. Further, the purified hsp 10 elicited strong delayed-type hypersensitivity reactions in guinea pigs sensitized to M. leprae. The strong T cell responses against the M. leprae 10-kD protein suggest a role for this heat-shock cognate protein in the protective/resistant responses to infection

    Diagnostic accuracy of different imaging modalities following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer

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    BACKGROUND: Periampullary cancer includes cancer of the head and neck of the pancreas, cancer of the distal end of the bile duct, cancer of the ampulla of Vater, and cancer of the second part of the duodenum. Surgical resection is the only established potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Other imaging methods such as magnetic resonance imaging (MRI), positron emission tomography (PET), PET-CT, and endoscopic ultrasound (EUS) have been used to detect local invasion or distant metastases not visualised on CT scanning which could prevent unnecessary laparotomy. No systematic review or meta-analysis has examined the role of different imaging modalities in assessing the resectability with curative intent in patients with pancreatic and periampullary cancer. OBJECTIVES: To determine the diagnostic accuracy of MRI, PET scan, and EUS performed as an add-on test or PET-CT as a replacement test to CT scanning in detecting curative resectability in pancreatic and periampullary cancer. SEARCH METHODS: We searched MEDLINE, Embase, Science Citation Index Expanded, and Health Technology Assessment (HTA) databases up to 5 November 2015. Two review authors independently screened the references and selected the studies for inclusion. We also searched for articles related to the included studies by performing the "related search" function in MEDLINE (OvidSP) and Embase (OvidSP) and a "citing reference" search (by searching the articles that cite the included articles). SELECTION CRITERIA: We included diagnostic accuracy studies of MRI, PET scan, PET-CT, and EUS in patients with potentially resectable pancreatic and periampullary cancer on CT scan. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies. DATA COLLECTION AND ANALYSIS: Two review authors independently performed data extraction and quality assessment using the QUADAS-2 (quality assessment of diagnostic accuracy studies - 2) tool. Although we planned to use bivariate methods for analysis of sensitivities and specificities, we were able to fit only the univariate fixed-effect models for both sensitivity and specificity because of the paucity of data. We calculated the probability of unresectability in patients who had a positive index test (post-test probability of unresectability in people with a positive test result) and in those with negative index test (post-test probability of unresectability in people with a positive test result) using the mean probability of unresectability (pre-test probability) from the included studies and the positive and negative likelihood ratios derived from the model. The difference between the pre-test and post-test probabilities gave the overall added value of the index test compared to the standard practice of CT scan staging alone. MAIN RESULTS: Only two studies (34 participants) met the inclusion criteria of this systematic review. Both studies evaluated the diagnostic test accuracy of EUS in assessing the resectability with curative intent in pancreatic cancers. There was low concerns about applicability for most domains in both studies. The overall risk of bias was low in one study and unclear or high in the second study. The mean probability of unresectable disease after CT scan across studies was 60.5% (that is 61 out of 100 patients who had resectable cancer after CT scan had unresectable disease on laparotomy). The summary estimate of sensitivity of EUS for unresectability was 0.87 (95% confidence interval (CI) 0.54 to 0.97) and the summary estimate of specificity for unresectability was 0.80 (95% CI 0.40 to 0.96). The positive likelihood ratio and negative likelihood ratio were 4.3 (95% CI 1.0 to 18.6) and 0.2 (95% CI 0.0 to 0.8) respectively. At the mean pre-test probability of 60.5%, the post-test probability of unresectable disease for people with a positive EUS (EUS indicating unresectability) was 86.9% (95% CI 60.9% to 96.6%) and the post-test probability of unresectable disease for people with a negative EUS (EUS indicating resectability) was 20.0% (5.1% to 53.7%). This means that 13% of people (95% CI 3% to 39%) with positive EUS have potentially resectable cancer and 20% (5% to 53%) of people with negative EUS have unresectable cancer. AUTHORS' CONCLUSIONS: Based on two small studies, there is significant uncertainty in the utility of EUS in people with pancreatic cancer found to have resectable disease on CT scan. No studies have assessed the utility of EUS in people with periampullary cancer.There is no evidence to suggest that it should be performed routinely in people with pancreatic cancer or periampullary cancer found to have resectable disease on CT scan

    Optimal Design of Robust Combinatorial Mechanisms for Substitutable Goods

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    In this paper we consider multidimensional mechanism design problem for selling discrete substitutable items to a group of buyers. Previous work on this problem mostly focus on stochastic description of valuations used by the seller. However, in certain applications, no prior information regarding buyers' preferences is known. To address this issue, we consider uncertain valuations and formulate the problem in a robust optimization framework: the objective is to minimize the maximum regret. For a special case of revenue-maximizing pricing problem we present a solution method based on mixed-integer linear programming formulation

    Stochastic heating of cooling flows

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    It is generally accepted that the heating of gas in clusters of galaxies by active galactic nuclei (AGN) is a form of feedback. Feedback is required to ensure a long term, sustainable balance between heating and cooling. This work investigates the impact of proportional stochastic feedback on the energy balance in the intracluster medium. Using a generalised analytical model for a cluster atmosphere, it is shown that an energy equilibrium can be reached exponentially quickly. Applying the tools of stochastic calculus it is demonstrated that the result is robust with regard to the model parameters, even though they affect the amount of variability in the system.Comment: 7 pages, 6 figures, accepted by MNRAS, http://www.astro.soton.ac.uk/~gbp/pub/pavlovski_stochh.pd

    Improving cataract services in the Indian context.

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