54 research outputs found

    Predictive Power of Markets - Prediction Accuracy, Incentive Schemes, and Traders\u27 Biases

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    Accurate predictions are essential in many areas such as business and sports forecasting. Prediction markets are a promising approach for predicting uncertain future events and developments. This work demonstrates that markets are accurate predictors beyond the field of political stock markets. Moreover, the findings on trader\u27 biases and incentive schemes are valuable for designing future prediction markets

    Prediction Markets: How Do Incentive Schemes Affect Prediction Accuracy?

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    Granule cell raphes in the developing mouse cerebellum

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    The cerebellar cortex of many vertebrates shows a striking parasagittal compartmentation that is thought to play a role in the establishment and maintenance of functional cerebellar connectivity. Here, I demonstrate the existence of multiple parasagittal raphes of cells in the molecular layer of the developing cerebellar cortex of postnatal mouse. The histological appearance and immunostaining profile of the raphe cells suggest that they are migrating granule cells. I therefore conclude that the granule cell raphes previously described in birds also exist in a mammalian species. The raphes in mouse are visible on nuclear stains from around birth to postnatal day 6 and are frequently found at the boundaries of Purkinje cell segments that differentially express cadherins (“early-onset” parasagittal banding pattern). A similar relation between the raphe pattern and various markers for the early-onset banding pattern has been found in the chicken cerebellum. One of the cadherins mapped in the present study (OL-protocadherin) continues to be expressed in specific Purkinje cell segments until at least postnatal day 14. At this stage of development, the borders of the OL-protocadherin-positive Purkinje cell segments coincide with the borders of Purkinje cell segments that express zebrin II, a marker for the “late-onset” parasagittal banding pattern which persists in the adult cerebellum. These findings demonstrate that the early-onset banding pattern, as reflected in the complementary arrangement of raphes/Purkinje cell segments, and the late-onset pattern of zebrin II expression share at least some positional cues during development

    Comparing two different arginine vasopressin doses in advanced vasodilatory shock: a randomized, controlled, open-label trial

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    Purpose: To compare the effects of two arginine vasopressin (AVP) dose regimens on the hemodynamic response, catecholamine requirements, AVP plasma concentrations, organ function and adverse events in advanced vasodilatory shock. Methods: In this prospective, controlled, open-label trial, patients with vasodilatory shock due to sepsis, systemic inflammatory response syndrome or after cardiac surgery requiring norepinephrine >0.6μg/kg/min were randomized to receive a supplementary AVP infusion either at 0.033IU/min (n=25) or 0.067IU/min (n=25). The hemodynamic response, catecholamine doses, laboratory and organ function variables as well as adverse events (decrease in cardiac index or platelet count, increase in liver enzymes or bilirubin) were recorded before, 1, 12, 24 and 48h after randomization. A linear mixed effects model was used for statistical analysis in order to account for drop-outs during the observation period. Results: Heart rate and norepinephrine requirements decreased while MAP increased in both groups. Patients receiving AVP at 0.067IU/min required less norepinephrine (P=0.006) than those infused with AVP at 0.033IU/min. Arterial lactate and base deficit decreased while arterial pH increased in both groups. During the observation period, AVP plasma levels increased in both groups (both P<0.001), but were higher in the 0.067IU/min group (P<0.001) and in patients on concomitant hydrocortisone. The rate of adverse events and intensive care unit mortality was comparable between groups (0.033IU/min, 52%; 0.067IU/min, 52%; P=1). Conclusions: A supplementary AVP infusion of 0.067IU/min restores cardiovascular function in patients with advanced vasodilatory shock more effectively than AVP at 0.033IU/mi

    Arterial blood pressure during early sepsis and outcome

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    Objective: To evaluate the association between arterial blood pressure (ABP) during the first 24h and mortality in sepsis. Design: Retrospective cohort study. Setting: Multidisciplinary intensive care unit (ICU). Patients and participants: A total of 274 septic patients. Interventions: None. Measurements and results: Hemodynamic, and laboratory parameters were extracted from a PDMS database. The hourly time integral of ABP drops below clinically relevant systolic arterial pressure (SAP), mean arterial pressure (MAP), and mean perfusion pressure (MPP=MAP−central venous pressure) levels was calculated for the first 24h after ICU admission and compared with 28-day-mortality. Binary and linear regression models (adjusted for SAPS II as a measure of disease severity), and a receiver operating characteristic (ROC) analysis were applied. The areas under the ROC curve were largest for the hourly time integrals of ABP drops below MAP60mmHg (0.779 vs. 0.764 for ABP drops below MAP55mmHg; P≤0.01) and MPP 45mmHg. No association between the hourly time integrals of ABP drops below certain SAP levels and mortality was detected. One or more episodes of MAP<60mmHg increased the risk of death by 2.96 (CI 95%, 1.06-10.36, P=0.04). The area under the ROC curve to predict the need for renal replacement therapy was highest for the hourly time integral of ABP drops below MAP75mmHg. Conclusions: A MAP level≥60mmHg may be as safe as higher MAP levels during the first 24h of ICU therapy in septic patients. A higher MAP may be required to maintain kidney functio

    Antifactor Xa activity in critically ill patients receiving antithrombotic prophylaxis with standard dosages of certoparin: a prospective, clinical study

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    INTRODUCTION: Deep venous thrombosis with subsequent pulmonary embolism or post-thrombotic syndrome is a feared complication in the intensive care unit. Therefore, routine prophylactic anticoagulation is widely recommended. Aside from unfractionated heparin, low molecular weight heparins, such as certoparin, have become increasingly used for prophylactic anticoagulation in critically ill patients. In this prospective study, we evaluated the potency of 3,000 IU certoparin administered once daily to reach antithrombotic antifactor Xa (aFXa) levels of 0.1 to 0.3 IU/ml in 62 critically ill patients. METHODS: AFXa levels were determined 4, 12 and 24 h after injection of certoparin. Prothrombin time, activated partial thromboplastin time, antithrombin, fibrinogen, hemoglobin, platelet count, serum urea and creatinine concentrations were documented before and 12 and 24 h after injection of certoparin. RESULTS: Four hours after certoparin injection (n = 32), 28% of patients were within the antithrombotic aFXa range. After 12 and 24 h, 6% achieved antithrombotic aFXa levels. Because of a severe pulmonary embolism in one study patient, an interim analysis was performed, and the dosage of certoparin was increased to 3,000 IU twice daily. This regime attained recommended antithrombotic aFXa levels in 47%, 27%, 40% and 30% of patients at 4, 12, 16 and 24 h, respectively, after twice daily certoparin injection (n = 30). Antithrombin and fibrinogen concentrations slightly increased during the observation period. Low antithrombin concentrations before certoparin were independently correlated with underdosing of certoparin. Patients with aFXa levels <0.1 IU/ml 4 h after certoparin injection required vasopressors more often and had lower serum concentrations of creatinine and urea than patients with antithrombotic aFXa levels. CONCLUSION: Standard dosages of certoparin of 3,000 IU given once or twice daily are ineffective for attaining the recommended aFXa levels of 0.1 to 0.3 IU/ml in critically ill patients. Low antithrombin levels before certoparin administration were independently associated with low aFXa levels. Renal function and vasopressor therapy may further influence the effectiveness of certoparin in ensuring adequate antithrombotic prophylaxis

    Arterial blood pressure during early sepsis and outcome

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    OBJECTIVE: To evaluate the association between arterial blood pressure (ABP) during the first 24 h and mortality in sepsis. DESIGN: Retrospective cohort study. SETTING: Multidisciplinary intensive care unit (ICU). PATIENTS AND PARTICIPANTS: A total of 274 septic patients. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Hemodynamic, and laboratory parameters were extracted from a PDMS database. The hourly time integral of ABP drops below clinically relevant systolic arterial pressure (SAP), mean arterial pressure (MAP), and mean perfusion pressure (MPP = MAP - central venous pressure) levels was calculated for the first 24 h after ICU admission and compared with 28-day-mortality. Binary and linear regression models (adjusted for SAPS II as a measure of disease severity), and a receiver operating characteristic (ROC) analysis were applied. The areas under the ROC curve were largest for the hourly time integrals of ABP drops below MAP 60 mmHg (0.779 vs. 0.764 for ABP drops below MAP 55 mmHg; P or = 60 mmHg may be as safe as higher MAP levels during the first 24 h of ICU therapy in septic patients. A higher MAP may be required to maintain kidney function
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