Conducting interactive experiments online

Online labor markets provide new opportunities for behavioral research, but conducting economic experiments online raises important methodological challenges. This particularly holds for interactive designs. In this paper, we provide a methodological discussion of the similarities and differences between interactive experiments conducted in the laboratory and online. To this end, we conduct a repeated public goods experiment with and without punishment using samples from the laboratory and the online platform Amazon Mechanical Turk. We chose to replicate this experiment because it is long and logistically complex. It therefore provides a good case study for discussing the methodological and practical challenges of online interactive experimentation. We find that basic behavioral patterns of cooperation and punishment in the laboratory are replicable online. The most important challenge of online interactive experiments is participant dropout. We discuss measures for reducing dropout and show that, for our case study, dropouts are exogenous to the experiment. We conclude that data quality for interactive experiments via the Internet is adequate and reliable, making online interactive experimentation a potentially valuable complement to laboratory studies

Parasites of non-native freshwater fishes introduced into england and wales suggest enemy release and parasite acquisition

When non-native species are introduced into a new range, their parasites can also be introduced, with these potentially spilling-over into native hosts. However, in general, evidence suggests that a high proportion of their native parasites are lost during introduction and infections by some new parasites from the native range might occur, potentially resulting in parasite spill-back to native species. These processes were investigated here using parasite surveys and literature review on seven non-native freshwater fishes introduced into England and Wales. Comparison of the mean numbers of parasite species and genera per population for each fish species England andWaleswith their native ranges revealed\9 % of the native parasite fauna were present in their populations in England and Wales. There was no evidence suggesting these introduced parasites had spilled over into sympatric native fishes. The non-native fishes did acquire parasites following their introduction, providing potential for parasite spill-back to sympatric fishes, and resulted in non-significant differences in overall mean numbers of parasites per populations between the two ranges. Through this acquisition, the non-native fishes also had mean numbers of parasite species and genera per population that were not significantly different to sympatric native fishes. Thus, the non-native fishes in England and Wales showed evidence of enemy release, acquired new parasites following introduction providing potential for spill-back, but showed no evidence of parasite spill-over

Mastering Blockchain: distributed ledgers, decentralization and smart contracts explained

Abstract Background The objectives of this investigation are to evaluate the use of health care services for non-communicable disease and prevention by children and adolescents and to identify the factors linked to the use of health care services. Methods This cross-sectional survey was conducted between December 2014 and January 2015 among 1198 parents of students aged between 5 and 18 years attending 12 selected schools in the geographic area of Salerno and Naples, Italy, using a self-administered questionnarie. Results 68.2% of parents stated that had visited their general practitioner (GP) or family pediatrician (FP) with their child in the last year. 66.2% of children had had at least one visit to a specialist and more than half (54.8%) had had preventive care visits in the last year. The use of preventive care visits within last year was significantly higher amongst female, among those who had visited their GP or FP and among those who had a parent with a college degree or higher. The proportion of emergency department visits and hospital admissions reported were 12.8% and 4.7% respectively. Conclusion This results highlights the need of educational interventions for parents and adolescents in order to increase the utilization of preventive health services