Social Ties in a Public Good Experiment

The formation of social ties is examined in an experimental study of voluntary public good provision. The experimental design consists of three parts. In the first part the value orientation (attitude to a generalized other) is measured. In the second part couples play a multi-period public good game. In the third part the attitudes of subjects to their partners in the public good game is measured. The concept of social tie is operationalized as the difference between the measurements in the first and third parts. Evidence for the occurrence of social ties is found. These ties depend on the success of the interaction in the public good game.Public good, social ties, experiment

Incentive Systems in a Real Effort Experiment

In the reported experiment different payment schemes are examined on their incentive effects. Payment based on individual, team an d relative performance are compared. Subjects conducted computerized tasks that required substantial effort. The results show that individual and team payment induced the same effort levels. In team production free-riding occurred, but it was compensated by many subjects providing more effort than in case of individual pay. Effort was higher, but more variable in tournaments, while in case of varying abilities workers with relatively low ability worked very hard and drove up effort of the others. Finally, attitudes towards work and other workers differed strongly between conditions.Payment schemes, experiment

Social Ties in a Public Good Experiment

The formation of social ties is examined in an experimental study of voluntary public good provision. The experimental design consists of three parts. In the first part the value orientation (attitude to a generalized other) is measured. In the second part couples play a multi-period public good game. In the third part the attitudes of subjects to their partners in the public good game is measured. The concept of social tie is operationalized as the difference between the measurements in the first and third parts. Evidence for the occurrence of social ties is found. These ties depend on the success of the interaction in the public good game

On the Role of External Representations in Designing for Participatory Sensemaking

Public issues demand highly complex collaborations in which different (public, private) stakeholders, each with their own complementary or conflicting interests, expertise and experiences, work toward public good. Typically, collaborative technological applications function to represent people’s ideas and to enable the exchange of representational messages between people. By contrast, we designed [X]Changing Perspectives ([X]CP): an interactive table-system for multi-stakeholder collaboration around public issues. The system aims, not to represent views but rather, to scaffold the emergence of situated meaningful couplings in face-to-face interactions. It helps people to align their visual attention, materialises their input and provokes associations. However, [X]CP does contain representations, such as symbols, tangibles and an interactive visualisation. In reflecting on its design and use, we analyse what these representations do, as seen from the perspective of embodied, participatory sensemaking. We explain how representations are not the foundational building blocks of the system, and how they do not have fixed meanings. Rather, as scaffolds, our representations add a layer of artificial structure that guides the ongoing interactive couplings between people, contributing to participatory sensemaking. Applying this approach to the design of mediating technologies for multi-stakeholder collaborations can open up new ways of interacting and understanding between stakeholders without disrupting their collaboration

Validation of a cerebral hemodynamic model with personalized calibration in patients with aneurysmal subarachnoid hemorrhage

This study aims to validate a numerical model developed for assessing personalized circle of Willis (CoW) hemodynamics under pathological conditions. Based on 66 computed tomography angiography images, investigations were obtained from 43 acute aneurysmal subarachnoid hemorrhage (aSAH) patients from a local neurovascular center. The mean flow velocity of each artery in the CoW measured using transcranial Doppler (TCD) and simulated by the numerical model was obtained for comparison. The intraclass correlation coefficient (ICC) over all cerebral arteries for TCD and the numerical model was 0.88 (N = 561; 95% CI 0.84–0.90). In a subgroup of patients who had developed delayed cerebral ischemia (DCI), the ICC had decreased to 0.72 but remained constant with respect to changes in blood pressure, Fisher grade, and location of ruptured aneurysm. Our numerical model showed good agreement with TCD in assessing the flow velocity in the CoW of patients with aSAH. In conclusion, the proposed model can satisfactorily reproduce the cerebral hemodynamics under aSAH conditions by personalizing the numerical model with TCD measurements. Clinical trial registration: [http://www.trialregister.nl/], identifier [NL8114]

Perinatal death beyond 41 weeks pregnancy : An evaluation of causes and substandard care factors as identified in perinatal audit in the Netherlands

Peer reviewedPublisher PD

A Reassessment of the Precision of Carbonate Clumped Isotope Measurements: Implications for Calibrations and Paleoclimate Reconstructions

Carbonate clumped isotopes offer a potentially transformational tool to interpret Earth's history, but the proxy is still limited by poor interlaboratory reproducibility. Here, we focus on the uncertainties that result from the analysis of only a few replicate measurements to understand the extent to which unconstrained errors affect calibration relationships and paleoclimate reconstructions. We find that highly precise data can be routinely obtained with multiple replicate analyses, but this is not always done in many laboratories. For instance, using published estimates of external reproducibilities we find that typical clumped isotope measurements (three replicate analyses) have margins of error at the 95% confidence level (CL) that are too large for many applications. These errors, however, can be systematically reduced with more replicate measurements. Second, using a Monte Carlo‐type simulation we demonstrate that the degree of disagreement on published calibration slopes is about what we should expect considering the precision of Δ47 data, the number of samples and replicate analyses, and the temperature range covered in published calibrations. Finally, we show that the way errors are typically reported in clumped isotope data can be problematic and lead to the impression that data are more precise than warranted. We recommend that uncertainties in Δ47 data should no longer be reported as the standard error of a few replicate measurements. Instead, uncertainties should be reported as margins of error at a specified confidence level (e.g., 68% or 95% CL). These error bars are a more realistic indication of the reliability of a measurement.This study was funded by the Swiss National Science Foundation project 200020_160046, 200021_143485, 200021_169849, and IZK022–160377, ETH research project ETH-33 14-1, and by Australian Research Council Australian Laureate Fellowship FL12010005

Regression discontinuity analysis demonstrated varied effect of Treat-All on CD4 testing among Southern African countries

OBJECTIVE: To determine whether Treat-All policy impacted laboratory testing practices of antiretroviral therapy (ART) programs in Southern Africa.STUDY DESIGN AND SETTING: We used HIV cohort data from Lesotho, Malawi, Mozambique, South Africa, Zambia and Zimbabwe in a regression discontinuity design to estimate changes in pre-ART CD4 testing and viral load monitoring following national Treat-all adoption that occurred during 2016-2017. This study included more than 230,000 ART-naïve people living with HIV (PLHIV) aged five years or older who started ART within two years of national Treat-All adoption.RESULTS: We found pre-ART CD4 testing decreased following adoption of Treat-All recommendations in Malawi (-21.4 percentage points (pp), 95% CI: -26.8, -16.0) and in Mozambique (-8.8pp, 95% CI: -14.9, -2.8), but increased in Zambia (+2.7pp, 95% CI: +0.4, +5.1). Treat-All policy had no effect on viral load monitoring, except among females in South Africa (+7.1pp, 95% CI: +1.1, +13.0).CONCLUSION: Treat-All policy expanded ART eligibility, but led to reductions in pre-ART CD4 testing in some countries that may weaken advanced HIV disease management. Continued and expanded support of CD4 and viral load laboratory capacity is needed to further improve treatment successes and allow for uniform evaluation of ART implementation across Southern Africa.</p