Effects of school choice on the margin: The cream is already skimmed

Critics of school choice argue that cream-skimming will worsen outcomes for those left behind in public schools. Since “high ability” families may have already sorted themselves out of the schools in question, this paper will examine whether existing within-school heterogeneity leaves any scope for cream-skimming to operate. It asks, “given the current level of within-school heterogeneity, how strong would peer effects have to be to significantly worsen outcomes for those left behind?” In order for cream-skimming to lower math test scores by one half-year's progress, the peer effect would have to be as strong as increasing class sizes by 8–20 students, or cutting per-student funding by $400–2000. These results indicate that current levels of within-school heterogeneity are so low that peer effects would have to be unrealistically strong to give cream-skimming any bite.     

Measurement of three-dimensional hand kinematics during swimming with a motion capture system: a feasibility study

Current trends in swimming biomechanics are focused on accurate measurements. Nowadays, reliable calibration methods have been proposed to reach an accuracy of about 1 mm on rigid structure. But the question remains about the final accuracy for three-dimensional hand kinematics measurement during the underwater phase of front crawl swimming. Furthermore, most research is based on manual tracking with two or more cameras. In this paper we propose a protocol to acquire three-dimensional hand kinematics when swimming in a specific pool with a motion analysis system behind windows. Results highlight the benefits of using such a system in terms of accuracy and feasibility: the time allowed for post-processing is ten times lower and the quantified improved accuracy is better than with manual tracking.     

Speaking Like a State: Listening to Benjamin Franklin in Times of Terror

This essay reconstitutes Benjamin Franklin's characteristic political style as a particular inflection of liberal irony, arguing for a way of speaking today that checks arrogance with humility and attempting to unlock the psychosocial economy of political enjoyment implicit in this rhetoric. To do so, the essay traverses four bodies of discourse (including recent political thinking about civic character, Franklin's oratory in 1787 at the constitutional convention, passages from his letters, and an excerpt from his autobiography) in order to extract strategies for managing situations in which democracy becomes prone to the enjoyments of terror and tyranny.     

Conservation of stained glass windows with protective glazing: Main results from the European VIDRIO research programme

The methodology of protecting the European stained glass windows against environmental risk (e.g. meteorological factors, air pollution, microorganisms) by means of an external glazing is not new. In spite of many scientific studies carried out in the last 20 years, some questions were still up for discussion. The European VIDRIO (2002–2005) project gave an answer to these questions. The research carried out by the different project partners established a new multidisciplinary approach aimed at evaluating the efficiency of the protective glazing systems and their effects on stained glass windows conservation, and finally at assessing the most appropriate strategy to preserve stained glass windows. Scientific results showed that the so-called isothermal glazing (i.e. ventilation by the air coming from the inside of the building) protected efficiently the ancient stained glass window from environmental attack (i.e. rain, pollutants, condensation, thermal shocks) with very limited secondary effects. The scientific research highlighted that its efficiency was strongly related to the technical design of the protective system. In particular, the ventilation and the size of the interspace had to be carefully considered. The research developed within the VIDRIO project was turned into general recommendations to the owners and practitioners on the best practice for the stained glass windows future conservation.     

Amateur scientists, the international geophysical year, and the ambitions of Fred Whipple

The contribution of amateur scientists to the International Geophysical Year (IGY) was substantial, especially in the arena of spotting artificial satellites. This article examines how Fred L. Whipple and his colleagues recruited satellite spotters for Moonwatch, a program for amateur scientists initiated by the Smithsonian Astrophysical Observatory (SAO) in 1956. At the same time, however, the administrators with responsibility for the IGY program closely monitored and managed--sometimes even contested--amateur participation. IGY programs like Moonwatch provided valuable scientific information and gave amateurs opportunities to contribute actively to the research of professional scientists. Moonwatch, which operated until 1975, eventually became the public face of a vast satellite-tracking network that expanded the SAO's global reach and helped further Whipple's professional goals. Understanding amateurs' interactions with the professional science community enables us better to understand the IGY as a phenomenon that enlisted broad participation and transcended traditional boundaries between professional and amateur scientists.