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The Cutting Edge of Modernity: Machine Tools in the United States and Germany 1930-1945
This paper aims to examine the difference between US and European manufacturing before and during the World War II, focusing on the key technology in the metal-working sector: machine tools. We present a new data set covering the installed capacity of metal-working tools in the United States and Germany for the period 1930-1945. The existing literature is heavily dependent on assumptions about the different type of machine tools in use on either side of the Atlantic. So far, systematic comparison has been limited to case studies. This is the first attempt to quantify the differences in this key technology for the entirety of metal-working in both economies. The enormous detail of the statistical sources we have uncovered allows us to combine aggregation and a degree of specificity, which exceeds that of any previous case study. In the German case, the original data is divided into well over a hundred sub-categories. For comparative purposes, we have identified 19 major classes of machines, which aggregate over 50 sub-categories. Our results suggest the need for a far more nuanced understanding of metal-working than the dichotomous picture of American mass manufacture, reliant on special-purpose tools, and European craft manufacturing employing general-purpose machinery. For 1930, we find a remarkable similarity in machine to worker ratios between Germany and the United States. There are differences in certain key areas. However, the US stock of metal-working tools is not yet distinguished by a clear commitment to mass production technology. For the period after 1935, until the early 1940s, our data suggest a remarkable degree of convergence. The American stock stagnated. In some areas, there was disinvestment. And the average age of machinery rose dramatically. By contrast, Germany entered a period of rapid catch-up, which appears to have continued into the early years of the war. By 1940, German metal-working came close to matching its American counterpart in terms of the number of workers employed and the quantity and types of machines installed. German machines were, on average, far younger. This process of catching-up, however, was dramatically reversed during World War II. Over a period of no more than four years the American stock expanded by over eighty percent and growth was markedly concentrated in key categories of mass production equipment. It appears that it was only in this period that mass production machinery came to truly dominate US metal-working. German investment, albeit moving in the same direction, failed to match the new intensity of American commitment to mass production in some key machinery classe
Autophagy coordinates chondrocyte development and early joint formation in zebrafish
Autophagy is a catabolic process responsible for the removal of waste and damaged cellular components by lysosomal degradation. It plays a key role in fundamental cell processes, including ER stress mitigation, control of cell metabolism, and cell differentiation and proliferation, all of which are essential for cartilage cell (chondrocyte) development and survival, and for the formation of cartilage. Correspondingly, autophagy dysregulation has been implicated in several skeletal disorders such as osteoarthritis and osteoporosis. To test the requirement for autophagy during skeletal development in zebrafish, we generated an atg13 CRISPR knockout zebrafish line. This line showed a complete loss of atg13 expression, and restricted autophagic activity in vivo. In the absence of autophagy, chondrocyte maturation was accelerated, with chondrocytes exhibiting signs of premature hypertrophy. Focussing on the jaw element, autophagy disruption affected joint articulation causing restricted mouth opening. This gross behavioural phenotype corresponded with a failure to thrive, and death in homozygote atg13 nulls within 17Â days. Taken together, our results are consistent with autophagy contributing to the timely regulation of chondrocyte maturation and for extracellular matrix formation
Statistical issues related to dietary intake as the response variable in intervention trials.
The focus of this paper is dietary intervention trials. We explore the statistical issues involved when the response variable, intake of a food or nutrient, is based on self-report data that are subject to inherent measurement error. There has been little work on handling error in this context. A particular feature of self-reported dietary intake data is that the error may be differential by intervention group. Measurement error methods require information on the nature of the errors in the self-report data. We assume that there is a calibration sub-study in which unbiased biomarker data are available. We outline methods for handling measurement error in this setting and use theory and simulations to investigate how self-report and biomarker data may be combined to estimate the intervention effect. Methods are illustrated using data from the Trial of Nonpharmacologic Intervention in the Elderly, in which the intervention was a sodium-lowering diet and the response was sodium intake. Simulations are used to investigate the methods under differential error, differing reliability of self-reports relative to biomarkers and different proportions of individuals in the calibration sub-study. When the reliability of self-report measurements is comparable with that of the biomarker, it is advantageous to use the self-report data in addition to the biomarker to estimate the intervention effect. If, however, the reliability of the self-report data is low compared with that in the biomarker, then, there is little to be gained by using the self-report data. Our findings have important implications for the design of dietary intervention trials. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd
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