341 research outputs found

    On rational delegations in liquid democracy

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    Liquid democracy is a proxy voting method where proxies are delegable. We propose and study a game-theoretic model of liquid democracy to address the following question: when is it rational for a voter to delegate her vote? We study the existence of pure-strategy Nash equilibria in this model, and how group accuracy is affected by them. We complement these theoretical results by means of agent-based simulations to study the effects of delegations on group's accuracy on variously structured social networks

    On rational delegations in liquid democracy

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    Liquid democracy is a proxy voting method where proxies are delegable. We propose and study a game-theoretic model of liquid democracy to address the following question: when is it rational for a voter to delegate her vote? We study the existence of pure-strategy Nash equilibria in this model, and how group accuracy is affected by them. We complement these theoretical results by means of agent-based simulations to study the effects of delegations on group's accuracy on variously structured social networks

    Voriconazole MICs are predictive for the outcome of experimental disseminated scedosporiosis

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    Scedosporiosis is associated with a mortality rate of up to 90% in patients suffering from disseminated infections. Recommended first-line treatment is voriconazole, but epidemiological cut-off values and clinical breakpoints have not been determined. Objectives: To correlate voriconazole treatment response in mice suffering from disseminated scedosporiosis with MIC values determined using CLSI broth microdilution, Etest (bioMe´rieux) and disc diffusio

    A New Method for Searching for Free Fractional Charge Particles in Bulk Matter

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    We present a new experimental method for searching for free fractional charge in bulk matter; this new method derives from the traditional Millikan liquid drop method, but allows the use of much larger drops, 20 to 100 mm in diameter, compared to the traditional method that uses drops less than 15 mm in diameter. These larger drops provide the substantial advantage that it is then much easier to consistently generate drops containing liquid suspensions of powdered meteorites and other special minerals. These materials are of great importance in bulk searches for fractional charge particles that may have been produced in the early universe.Comment: 17 pages, 5 figures in a singl PDF file (created from WORD Doc.). Submitted to Review of Scientific Instrument

    The Search for Stable, Massive, Elementary Particles

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    In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches - what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review.Comment: 34 pages, 8 eps figure

    In vitro and in vivo testing of stereolithography (SLA)-manufactured haemocompatible photopolymers for blood pump

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    A major medical problem of state-of-the-art heart ventricular assist devices (LVADs) is device-induced thrombus formation due to inadequate blood-flow dynamics generated by the blood pump rotor. The latter is a highly complex device, with difficulties during conventional manufacturing through milling or casting. Therefore, the additive manufacturing technology relying on stereo-lithography (SLA) capable of producing parts of significantly increased freedom for a blood-flow-compatible, thrombus-risk-free design was chosen as novel and flexible technology for that type of application. However, as yet state-of-the-art SLA is not suitable to produce fully safe blood-contacting devices. Therefore, the present experiment covered chemical, mechanical, rheological, tribological, and complex biocompatibility characterization in accordance with i.a. ISO 10993 standards, including hemolysis and an acute thrombogenicity blood test on fresh animal blood (both as innovative laboratory tests to avoid animal usage in preclinical studies) with a special focus on testing demonstrators of miniaturized blood pump rotors. The conducted tests indicated acceptable biocompatibility of the material and a slight improvement in biocompatibility with surface modification. Additionally, a high biocompatibility of the tested materials was confirmed. Based on studies and simulations, stereolithography (SLA) as an additive manufacturing technology with significantly increased freedom for a blood-flow-compatible, thrombus-risk-free design was chosen as a novel and flexible technology basis in the 4DbloodROT project to enable future manufacturing of rotors with exceptional biomimetic complexity

    Evaluation of a laboratory-based high-throughput SARS-CoV-2 antigen assay for non-COVID-19 patient screening at hospital admission

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    Several rapid antigen tests (RATs) for the detection of SARS-CoV-2 were evaluated recently. However, reliable performance data for laboratory-based, high-throughput antigen tests are lacking. Therefore and in response to a short-term shortage of PCR reagents, we evaluated DiaSorin's LIAISON SARS-CoV-2 antigen test in comparison to RT-qPCR, and concerning the application of screening non-COVID-19 patients on hospital admission. Applying the manufacturer-recommended cut-off of 200 arbitrary units (AU/mL) the specificity of the LIAISON Test was 100%, the overall analytical sensitivity 40.2%. Lowering the cut-off to 100 AU/mL increased the sensitivity to 49.7% and decreased the specificity to 98.3%. Confining the analysis to samples with an RT-qPCR result < 25 Ct resulted in a sensitivity of 91.2%. The quality of the LIAISON test is very similar to that of good RATs described in the literature with the advantage of high throughput and the disadvantage of relatively long analysis time. It passes the WHO quality criteria for rapid antigen tests and is characterized by particularly high specificity. The LIAISON test can therefore be used for the same applications as recommended for RATs by the WHO. Due to limited sensitivity, the LIAISON test should only be used for screening, if PCR-based assays are not available

    Increased neutrophil-lymphocyte ratio is a poor prognostic factor in patients with primary operable and inoperable pancreatic cancer

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    Background: The neutrophil-lymphocyte ratio (NLR) has been proposed as an indicator of systemic inflammatory response. Previous findings from small-scale studies revealed conflicting results about its independent prognostic significance with regard to different clinical end points in pancreatic cancer (PC) patients. Therefore, the aim of our study was the external validation of the prognostic significance of NLR in a large cohort of PC patients. Methods: Data from 371 consecutive PC patients, treated between 2004 and 2010 at a single centre, were evaluated retrospectively. The whole cohort was stratified into two groups according to the treatment modality. Group 1 comprised 261 patients with inoperable PC at diagnosis and group 2 comprised 110 patients with surgically resected PC. Cancer-specific survival (CSS) was assessed using the Kaplan–Meier method. To evaluate the independent prognostic significance of the NLR, the modified Glasgow prognostic score (mGPS) and the platelet-lymphocyte ratio univariate and multivariate Cox regression models were applied. Results: Multivariate analysis identified increased NLR as an independent prognostic factor for inoperable PC patients (hazard ratio (HR)=2.53, confidence interval (CI)=1.64–3.91, P<0.001) and surgically resected PC patients (HR=1.61, CI=1.02–2.53, P=0.039). In inoperable PC patients, the mGPS was associated with poor CSS only in univariate analysis (HR=1.44, CI=1.04–1.98). Conclusion: Risk prediction for cancer-related end points using NLR does add independent prognostic information to other well-established prognostic factors in patients with PC, regardless of the undergoing therapeutic modality. Thus, the NLR should be considered for future individual risk assessment in patients with PC
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