3,212 research outputs found

    Designing Chatbots for Crises: A Case Study Contrasting Potential and Reality

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    Chatbots are becoming ubiquitous technologies, and their popularity and adoption are rapidly spreading. The potential of chatbots in engaging people with digital services is fully recognised. However, the reputation of this technology with regards to usefulness and real impact remains rather questionable. Studies that evaluate how people perceive and utilise chatbots are generally lacking. During the last Kenyan elections, we deployed a chatbot on Facebook Messenger to help people submit reports of violence and misconduct experienced in the polling stations. Even though the chatbot was visited by more than 3,000 times, there was a clear mismatch between the users’ perception of the technology and its design. In this paper, we analyse the user interactions and content generated through this application and discuss the challenges and directions for designing more effective chatbots

    Multi-phonon Raman scattering in semiconductor nanocrystals: importance of non-adiabatic transitions

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    Multi-phonon Raman scattering in semiconductor nanocrystals is treated taking into account both adiabatic and non-adiabatic phonon-assisted optical transitions. Because phonons of various symmetries are involved in scattering processes, there is a considerable enhancement of intensities of multi-phonon peaks in nanocrystal Raman spectra. Cases of strong and weak band mixing are considered in detail. In the first case, fundamental scattering takes place via internal electron-hole states and is participated by s- and d-phonons, while in the second case, when the intensity of the one-phonon Raman peak is strongly influenced by the interaction of an electron and of a hole with interface imperfections (e. g., with trapped charge), p-phonons are most active. Calculations of Raman scattering spectra for CdSe and PbS nanocrystals give a good quantitative agreement with recent experimental results.Comment: 16 pages, 2 figures, E-mail addresses: [email protected], [email protected], [email protected], accepted for publication in Physical Review

    Interleukin-1 regulates multiple atherogenic mechanisms in response to fat feeding

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    Background: Atherosclerosis is an inflammatory process that develops in individuals with known risk factors that include hypertension and hyperlipidaemia, influenced by diet. However, the interplay between diet, inflammatory mechanisms and vascular risk factors requires further research. We hypothesised that interleukin-1 (IL-1) signaling in the vessel wall would raise arterial blood pressure and promote atheroma. Methodology/Principal Findings: Apoe(-/-) and Apoe(-/-)/IL-1R1(-/-) mice were fed high fat diets for 8 weeks, and their blood pressure and atherosclerosis development measured. Apoe(-/-)/IL-R1(-/-) mice had a reduced blood pressure and significantly less atheroma than Apoe(-/-) mice. Selective loss of IL-1 signaling in the vessel wall by bone marrow transplantation also reduced plaque burden (p<0.05). This was associated with an IL-1 mediated loss of endothelium-dependent relaxation and an increase in vessel wall Nox 4. Inhibition of IL-1 restored endothelium-dependent vasodilatation and reduced levels of arterial oxidative stress. Conclusions/Significance: The IL-1 cytokine system links atherogenic environmental stimuli with arterial inflammation, oxidative stress, increased blood pressure and atherosclerosis. This is the first demonstration that inhibition of a single cytokine can block the rise in blood pressure in response to an environmental stimulus. IL-1 inhibition may have profound beneficial effects on atherogenesis in man

    Bi-directional association between depression and HF: An electronic health records-based cohort study.

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    To determine whether a bi-directional relationship exists between depression and HF within a single population of individuals receiving primary care services, using longitudinal electronic health records (EHRs). This retrospective cohort study utilized EHRs for adults who received primary care services within a large healthcare system in 2006. Validated EHR-based algorithms identified 10,649 people with depression (depression cohort) and 5,911 people with HF (HF cohort) between January 1, 2006 and December 31, 2018. Each person with depression or HF was matched 1:1 with an unaffected referent on age, sex, and outpatient service use. Each cohort (with their matched referents) was followed up electronically to identify newly diagnosed HF (in the depression cohort) and depression (in the HF cohort) that occurred after the index diagnosis of depression or HF, respectively. The risks of these outcomes were compared (vs. referents) using marginal Cox proportional hazard models adjusted for 16 comorbid chronic conditions. 2,024 occurrences of newly diagnosed HF were observed in the depression cohort and 944 occurrences of newly diagnosed depression were observed in the HF cohort over approximately 4-6 years of follow-up. People with depression had significantly increased risk for developing newly diagnosed HF (HR 2.08, 95% CI 1.89-2.28) and people with HF had a significantly increased risk of newly diagnosed depression (HR 1.34, 95% CI 1.17-1.54) after adjusting for all 16 comorbid chronic conditions. These results provide evidence of a bi-directional relationship between depression and HF independently of age, sex, and multimorbidity from chronic illnesses

    Non-geniculate coralline algae (Carallinales, Rhodophyta) on Heron Reef, Great Barrier Reef (Australia)

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    This is the first modern, comprehensive account of non-geniculate coralline algae (Corallinales, Rhodophyta) occurring on the Great Barrier Reef (Heron Reef). Species were identified in a modern context, using reproductive and vegetative anatomy as diagnostic features. In a collection of 300 specimens, 11 different species were identified. Eight of the species were found exclusively on calcareous substrata, one was exclusively epiphytic, while the remaining two were both epiphytic and found growing on calcareous substrata. Although none of the species are new to science, one is newly recorded for Australia (Hydrolithon reinboldii) and 5 are newly recorded for the Great Barrier Reef region (Spongites fruticulosus, Lithophyllum frondosum, L. pustulatum, Mastophora pacifica and Mesophyllum erubescens). Collections made by A. B. Cribb in the 1960s on Heron Reef were also studied, once again using reproductive and vegetative anatomy as diagnostic features. Illustrations of each species and a tabular key are provided to facilitate non-geniculate coralline algal identification on Heron Reef. Information on their distribution and growth-forms are provided along with references to more detailed morphological accounts and published illustrations. The reported species are compared to findings from other tropical reef systems

    Subthreshold antiproton production in proton-carbon reactions

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    Data from KEK on subthreshold antiproton as well as on pi(+-) and K(+-) production in proton-nucleus reactions are described at projectile energies between 3.5 and 12.0 GeV. We use a model which considers a hadron-nucleus reaction as an incoherent sum over collisions of the projectile with a varying number of target nucleons. It samples complete events and allows thus for the simultaneous consideration of all particle species measured. The overall reproduction of the data is quite satisfactory. It is shown that the contributions from the interaction of the projectile with groups of several target nucleons are decisive for the description of subthreshold production. Since the collective features of subthreshold production become especially significant far below the threshold, the results are extrapolated down to COSY energies. It is concluded that an antiproton measurement at ANKE-COSY should be feasible, if the high background of other particles can be efficiently suppressed.Comment: 15 pages, 5 figures, gzipped tar file, submitted to J. Phys. G v2: Modification of text due to demands of referee

    A panel analysis of UK industrial company failure

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    We examine the failure determinants for large quoted UK industrials using a panel data set comprising 539 firms observed over the period 1988-93. The empirical design employs data from company accounts and is based on Chamberlain’s conditional binomial logit model, which allows for unobservable, firm-specific, time-invariant factors associated with failure risk. We find a noticeable degree of heterogeneity across the sample companies. Our panel results show that, after controlling for unobservables, lower liquidity measured by the quick assets ratio, slower turnover proxied by the ratio of debtors turnover, and profitability were linked to the higher risk of insolvency in the analysis period. The findings appear to support the proposition that the current cash-flow considerations, rather than the future prospects of the firm, determined company failures over the 1990s recession

    Examining the relationship between altered brain functional connectome and disinhibition across 33 impulsive and compulsive behaviours

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    Impulsive and compulsive problem behaviours are associated with a variety of mental disorders. Latent phenotyping indicates the expression of impulsive and compulsive problem behaviours is predominantly governed by a transdiagnostic 'disinhibition' phenotype. In a cohort of 117 individuals, recruited as part of the Neuroscience in Psychiatry Network (NSPN), we examined how brain functional connectome and network properties relate to disinhibition. Reduced functional connectivity within a subnetwork of frontal (especially right inferior frontal gyrus), occipital and parietal regions was linked to disinhibition. Findings provide insights into neurobiological pathways underlying the emergence of impulsive and compulsive disorders
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