Mitchell Lorentsen (milklinen0)

This paper aims at resolving a puzzle about the persuasiveness of bootstrapping. On the one hand, bootstrapping is not a persuasive method of settling questions about the reliability of a source. On the other hand, our beliefs that our sense apparatus is reliable is based on other empirically formed beliefs, that is, they are acquired via a presumably complex bootstrapping process. I will argue that when we doubt the reliability of a source, bootstrapping is not a persuasive method for coming to believe that the source is reliable. However, when being initially unaware of a source and its reliability, as in the case of forming beliefs about our sense apparatus, bootstrapping can be eventually persuasive. © 2020 The Authors. Ratio published by John Wiley & Sons Ltd.The paper presents a transformation of a multi-stage optimal control model with random switching time to an age-structured optimal control model. Following the mathematical transformation, the advantages of the present approach, as compared to a standard backward approach, are discussed. They relate in particular to a compact and unified representation of the two stages of the model the applicability of well-known numerical solution methods and the illustration of state and control dynamics. The paper closes with a simple example on a macroeconomic shock, illustrating the workings and advantages of the approach. © The Author(s) 2019.Cinema had long been hailed by Bolshevik party leaders as a crucial ally of the Soviet mass enlightenment project. By the mid-1920s, however, Soviet psychologists, educators and practitioners of 'child science' (pedology) were pointing to the grave effects that the consumption of commercial cinema was exerting on the physical, mental and moral health of Soviet young people. Diagnosing an epidemic of 'film mania', specialists battled to curtail the NEP-era practices of film production and demonstration that had rendered cinema 'toxic' to children. Campaigns to 'healthify' Soviet cinema, first manifesting in the organization of child-friendly screenings and forms of 'cultural enlightenment work', soon extended to attempts to develop a new children's film repertoire based on the results of psycho-physiological viewer studies. A vast variety of pedological research institutions established during the late 1920s and early 1930s began to experimentally test cinema's effects on children with the view of assisting the production of films that could cultivate a sound mind and body. Tracing a link between the findings of pedological viewer studies and the 'healthy' cinema championed in the 1930s, this article sheds light on the vital role played by medical and scientific expertise in shaping Stalinist culture. © The Author(s) 2019.This study presents boron (B) concentration and isotope data for white mica from (ultra)high-pressure (UHP), subduction-related metamorphic rocks from Lago di Cignana (Western Alps, Italy). These rocks are of specific geological interest, because they comprise the most deeply subducted rocks of oceanic origin worldwide. Boron geochemistry can track fluid-rock interaction during their metamorphic evolution and provide important insights into mass transfer processes in subduction zones. The highest B contents (up to 345 μg/g B) occur in peak metamorphic phengite from a garnet-phengite quartzite. The B isotopic composition is variable (δ11B = - 10.3 to - 3.6%) and correlates positively with B concentrations. Based on similar textures and major element mica composition, neither textural differences, prograde growth zoning, diffusion nor a retrograde overprint can explain this correlation. Modelling shows that B devolatilization during metamorphism can explain the general trend, but fails to account for the wide can be successfully modelled as fluid-rock interaction with low-to-moderate ( less then 3) fluid/rock ratios, where mica equilibrates with a fluid into which B preferentially partitions, causing leaching of