369 research outputs found

    ATTENUATING PERCEIVED PRIVACY RISK OF LOCATION-BASED MOBILE SERVICES

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    The rapid diffusion of mobile devices has spurred the development and use of location-based mobile services (LBMS). LBMS have the potential to add value to businesses through sale of LBMS applications and targeted marketing of products and services. However, studies have shown that individuals’ intention to use LBMS is plagued by the perceived privacy risks of disclosing location and personal information. This study examines how various consumption values may weaken the negative influence of perceived privacy risk on individuals’ intention to use LBMS based on the multi-dimensional concept of privacy risk, theory of consumption values, and privacy calculus. The attenuating effects of conditional, emotional, epistemic, functional, and social values are studied. Results of a survey of 194 potential users of a LBMS show that conditional, functional, and social values have significant attenuating effects. This study contributes to research by looking beyond the separate and direct effects of perceived privacy risk and consumption values to provide new insights on their joint influences. For practitioners such as LBMS providers and businesses’ marketing managers, the findings highlight the type of values that should be emphasized in designing and promoting LBMS

    Trust of Information on Social Media: An Elaboration Likelihood Model

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    Social media such as Twitter and Facebook are increasingly being used as a source of information in critical situations such as natural disasters and civil unrests. However, false information exists on social media and trusting false information not only leads users to make wrong decisions but can also have dire impact on the society. This research-in-progress examines how individuals process information on social media to determine whether or not to trust the information. Based on the elaboration likelihood model, a research model elucidating the effects of information quality, source credibility, and majority influence on users’ trust of information on social media is proposed. Further, the moderating effects of personal involvement and users’ prior knowledge are investigated. Results from a pilot survey indicate that majority influence has a stronger effect on trust than source credibility for social media users and they are likely to rely on information quality as well as source credibility and majority influence when their personal involvement is high

    Reading Consumer Reviews to Confirm My Expectations: The Accelerated Impact of Confirmation under Extreme Review Tones

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    This study examines how the initially perceived product value affects a consumer’s purchase intention after he/she reads various tones of online reviews. It proposes that the associations among the initially perceived product value, the level of confirmation made by reading reviews and final purchase intention would differ across review tones that; 1) when the tone is extreme, the impact of confirmation will be stronger than when the tone is moderate and 2) when the tone is favorable, the impact of initially perceived product value will be stronger than when the tone is critical. The survey was conducted to 276 online shopping mall users in Korea and most of hypotheses were supported. This study emphasizes that the impact of online review should be discussed together with the level of expectation that a customer had before reading online reviews, because the customers have to go through searching and screening processes before reading online reviews

    A prospective methicillin resistant staphylococcus aureus typing system for infection control : design and effectiveness

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    The uptake of Gadomer-17, as probed by fast dynamic T(1) measurements, was used to assess the vascular permeability surface-area product per leakage volume of tissue (k(Tofts)) of human glioma xenografts implanted in mice. With this approach we could discriminate between two types of glioma xenograft lines with a known difference in the perfused vascular architecture and degree of hypoxia. The T(1) data were analyzed according to the Tofts-Kermode compartment model. The fast-growing E102 tumor demonstrated a homogeneous distribution of the vascular permeability surface area across the tumor (mean k(Tofts) value = 0.18 +/- 0.05 min(-1)). The slowly growing E106 tumor showed a more heterogeneous pattern. Three perfused tumor areas with differences in vascular permeability surface area could be distinguished: a well-perfused periphery with high k(Tofts) values (0.24 +/- 0.04 min(-1)), perfused capillaries inside the tumor with low k(Tofts) values (0.108 +/- 0.026 min(-1)), and perfused capillaries adjacent to necrotic regions with high k(Tofts) values (0.29 +/- 0.10 min(-1)). On a different series of tumors, the hypoxic fractions were measured, and these were significantly higher in E106 tumors (0.14 +/- 0.05) compared to tumors of the E102 line (0.03 +/- 0.02)

    Photoproduction of pi0 omega off protons for E(gamma) < 3 GeV

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    Differential and total cross-sections for photoproduction of gamma proton to proton pi0 omega and gamma proton to Delta+ omega were determined from measurements of the CB-ELSA experiment, performed at the electron accelerator ELSA in Bonn. The measurements covered the photon energy range from the production threshold up to 3GeV.Comment: 8 pages, 13 figure

    K^0 pi^0 Sigma^+ and K^*0 Sigma^+ photoproduction off the proton

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    The exclusive reactions γpK0Σ+(1189)\gamma p \to K^{*0} \Sigma^+(1189) and γpK0π0Σ+(1189)\gamma p \to K^{0} \pi^{0}\Sigma^+(1189), leading to the p 4π0\pi^{0} final state, have been measured with a tagged photon beam for incident energies from threshold up to 2.5 GeV. The experiment has been performed at the tagged photon facility of the ELSA accelerator (Bonn). The Crystal Barrel and TAPS detectors were combined to a photon detector system of almost 4π\pi geometrical acceptance. Differential and total cross sections are reported. At energies close to the threshold, a flat angular distribution has been observed for the reaction γpK0π0Σ+\gamma p\to K^{0} \pi^{0}\Sigma^+ suggesting dominant s-channel production. Σ(1385)\Sigma^*(1385) and higher lying hyperon states have been observed. An enhancement in the forward direction in the angular distributions of the reaction γpK0Σ+\gamma p \to K^{*0}\Sigma^+ indicates a tt-channel exchange contribution to the reaction mechanism. The experimental data are in reasonable agreement with recent theoretical predictions.Comment: 11 pages, 13 figures, submitted to EPJ

    Lipid-soluble Vitamins A, D, and E in HIV-Infected Pregnant women in Tanzania.

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    There is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings. This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals. Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01). Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions

    In-medium ω\omega mass from the γ+Nbπ0γ+X\gamma + Nb \to \pi^{0}\gamma + X reaction

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    Data on the photoproduction of ω\omega mesons on nuclei have been re-analyzed in a search for in-medium modifications. The data were taken with the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn. First results from the analysis of the data set were published by D. Trnka et al. in Phys. Rev. Lett 94 (2005) 192303 \cite{david}, claiming a lowering of the ω\omega mass in the nuclear medium by 14% at normal nuclear matter density. The extracted ω\omega line shape was found to be sensitive to the background subtraction. For this reason a re-analysis of the same data set has been initiated and a new method has been developed to reduce the background and to determine the shape and absolute magnitude of the background directly from the data. Details of the re-analysis and of the background determination are described. The ω\omega signal on the NbNb target, extracted in the re-analysis, does not show a deviation from the corresponding line shape on a LH2LH_2 target, measured as reference. The earlier claim of an in-medium mass shift is thus not confirmed. The sensitivity of the ω\omega line shape to different in-medium modification scenarios is discussed.Comment: 13 pages and 11 figures, submitted for publicatio

    Modification of the ω\omega-Meson Lifetime in Nuclear Matter

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    The photo production of ω\omega mesons on the nuclei C, Ca, Nb and Pb has been measured using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the ω\omega meson cross section on the nuclear mass number has been compared with three different types of models, a Glauber analysis, a BUU analysis of the Giessen theory group and a calculation by the Valencia theory group. In all three cases, the inelastic ω\omega width is found to be 130150MeV/c2130-150 \rm{MeV/c^2} at normal nuclear matter density for an average 3-momentum of 1.1 GeV/c. In the restframe of the ω\omega meson, this inelastic ω\omega width corresponds to a reduction of the ω\omega lifetime by a factor 30\approx 30. For the first time, the momentum dependent ω\omegaN cross section has been extracted from the experiment and is in the range of 70 mb.Comment: 5 pages, 4 figure

    Clinical disorders affecting mesopic vision

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    Vision in the mesopic range is affected by a number of inherited and acquired clinical disorders. We review these conditions and summarize the historical background, describing the clinical characteristics alongside the genetic basis and molecular biological mechanisms giving rise to rod and cone dysfunction relevant to twilight vision. The current diagnostic gold standards for each disease are discussed and curative and symptomatic treatment strategies are summarized
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