Bots in Wikipedia: Unfolding their duties

The success of crowdsourcing systems such as Wikipedia relies on people participating in these systems. However, in this research we reveal to what extent human and machine intelligence is combined to carry out semi-automatic workflows of complex tasks. In Wikipedia, bots are used to realize such combination of human-machine intelligence. We provide an extensive overview on various edit types bots carry out in this regard through the analysis of 1,639 approved task requests. We classify existing tasks by an action-object-pair structure and reveal existing differences in their probability of occurrence depending on the investigated work context. In the context of community services, bots mainly create reports, whereas in the area of guidelines or policies bots are mostly responsible for adding templates to pages. Moreover, the analysis of existing bot tasks revealed insights that suggest general reasons, why Wikipedia’s editor community uses bots as well as approaches, how they organize machine tasks to provide a sustainable service. We conclude by discussing how these insights can prepare the foundation for further research

A Systematic Examination of Particle Motion in a Collapsing Magnetic Trap Model for Solar Flares

Context. It has been suggested that collapsing magnetic traps may contribute to accelerating particles to high energies during solar flares. Aims. We present a detailed investigation of the energization processes of particles in collapsing magnetic traps, using a specific model. We also compare for the first time the energization processes in a symmetric and an asymmetric trap model. Methods. Particle orbits are calculated using guiding centre theory. We systematically investigate the dependence of the energization process on initial position, initial energy and initial pitch angle. Results. We find that in our symmetric trap model particles can gain up to about 50 times their initial energy, but that for most initial conditions the energy gain is more moderate. Particles with an initial position in the weak field region of the collapsing trap and with pitch angles around 90 degrees achieve the highest energy gain, with betatron acceleration of the perpendicular energy the dominant energization mechanism. For particles with smaller initial pitch angle, but still outside the loss cone, we find the possibility of a significant increase in parallel energy. This increase in parallel energy can be attributed to the curvature term in the parallel equation of motion and the associated energy gain happens in the center of the trap where the field line curvature has its maximum. We find qualitatively similar results for the asymmetric trap model, but with smaller energy gains and a larger number of particles escaping from the trap.Comment: 11 pages, 13 figures. To be published in Astronomy and Astrophysic

Six Seconds Per Eyelid : the medical inspection of inmigrants at Ellis Island, 1892-1914

Beginning in 1892, immigrants to the United States were subject to a medical inspection, created to restrict the entry of persons with a eloathsome or dangerous contagiousn disease or mental deficiency. Ellis Island, which received over 10 million newcomers between 1900 and 1914, served as the largest ever medical screening facility. Far from reflecting a unified policy, the medical inspection offered a complicated compromise amidst a swirl of competing interests. Many industrialists blamed the waves of Southern and Eastern European immigrants for urban joblessness, filth, unrest, overcrowding, and disease. In an era of depression, labor groups opposed immigrant competitors for scarce jobs. Nativists believed immigrants could not overcome their defects because these were genetically transmitted. Germ theory proponents recognized communication of microorganisms as the problem, with controlling the spread of infections as the solution. Many Progressive reformers held that the scientific screening of immigrants offered a systematic solution for the disorder. Dozens of immigrant aid societies struggled to attenuate the effects of the inspection, and as depression subsided after 1900, employers, too, favored the influx of immigrants. This paper examines the social and political basis for the inspection, its realization at Ellis Island, and the reasons for its inability to debar large numbers of immigrants

Buscando desesperadamente la descentralización : las políticas de salud mexicanas en dos épocas de reforma (los años 20 y 30 y la década de los 80)

Este trabajo compara las reformas de salud en México durante las décadas de los 1920 y 1930, con las políticas que se iniciaron en ese país hacia mediados de la década de los 1980. Las primeras fueron apoyadas por la Fundación Rockefeller que favoreció la formación de unidades cooperativas locales de salud. En los ochenta el gobierno Mexicano y agencias financieras internacionales, como el Banco Interamericano de Desarrollo, promovieron reformas con el fin de reducir el gasto público en salud (como parte de las políticas de «ajuste estructural»). Una de las hipótesis de este trabajo es que al final, las reformas de salud no pudieron superar los obstáculos políticos de la centralización del poder fiscal y de la tradición de inequidad en la distribución de recursos. Sin embargo, uno de los resultados no esperados de la descentralización fue el incremento de la capacidad local de demandar una mayor redistribución de servicios sociales

Survival analysis of HDR brachytherapy versus reoperation versus temozolomide alone: a retrospective cohort analysis of recurrent glioblastoma multiforme

Objectives Tumour recurrence of glioblastoma multiforme (GBM) after initial treatment with surgical resection, radiotherapy and chemotherapy is an inevitable phenomenon. This retrospective cohort study compared the efficacy of interstitial high dose rate brachytherapy (HDR-BRT), re-resection and sole dose dense temozolomide chemotherapy (ddTMZ) in the treatment of recurrent glioblastoma after initial surgery and radiochemotherapy. Design Retropective cohort study. Setting Primary level of care with two participating centres. The geographical location was central Germany. Participants From January 2005 to December 2010, a total of 111 patients developed recurrent GBM after initial surgery and radiotherapy with concomitant temozolomide. The inclusion criteria were as follows: (1) histology-proven diagnosis of primary GBM (WHO grade 4), (2) primary treatment with resection and radiochemotherapy, and (3) tumour recurrence/progression. Interventions This study compared retrospectively the efficacy of interstitial HDR-BRT, re-resection and ddTMZ alone in the treatment of recurrent glioblastoma. Primary and secondary outcome measures Median survival, progression free survival and complication rate. Results Median survival after salvage therapy of the recurrence was 37, 30 and 26 weeks, respectively. The HDR-BRT group did significantly better than both the reoperation (p<0.05) and the ddTMZ groups (p<0.05). Moderate to severe complications in the HDR-BRT, reoperation and sole chemotherapy groups occurred in 5/50 (10%), 4/36 (11%) and 9/25 (36%) cases, respectively. Conclusions CT-guided interstitial HDR-BRT attained higher survival benefits in the management of recurrent glioblastoma after initial surgery and radiotherapy with concurrent temozolomide in comparison with the other treatment modalities. The low risk of complications of the HDR-BRT and the fact that it can be delivered percutaneously in local anaesthesia render it a promissing treatment option for selected patients which should be further evaluated