520 research outputs found

    Bayesian phylolinguistics infers the internal structure and the time-depth of the Turkic language family

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    Despite more than 200 years of research, the internal structure of the Turkic language family remains subject to debate. Classifications of Turkic so far are based on both classical historical–comparative linguistic and distance-based quantitative approaches. Although these studies yield an internal structure of the Turkic family, they cannot give us an understanding of the statistical robustness of the proposed branches, nor are they capable of reliably inferring absolute divergence dates, without assuming constant rates of change. Here we use computational Bayesian phylogenetic methods to build a phylogeny of the Turkic languages, express the reliability of the proposed branches in terms of probability, and estimate the time-depth of the family within credibility intervals. To this end, we collect a new dataset of 254 basic vocabulary items for thirty-two Turkic language varieties based on the recently introduced Leipzig–Jakarta list. Our application of Bayesian phylogenetic inference on lexical data of the Turkic languages is unprecedented. The resulting phylogenetic tree supports a binary structure for Turkic and replicates most of the conventional sub-branches in the Common Turkic branch. We calculate the robustness of the inferences for subgroups and individual languages whose position in the tree seems to be debatable. We infer the time-depth of the Turkic family at around 2100 years before present, thus providing a reliable quantitative basis for previous estimates based on classical historical linguistics and lexicostatistics

    Rigidity of lattice domes

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    The means of ensuring total rigidity of lattice domes, using comparison with solid shells of 1-3 layers are discussed. Irregularities of manufacture, processing, and other factors are considered, as they relate to diminution of rigidity. The discussion uses the concepts of upper and lower critical loads on the structure in question

    Conscientiousness, Extraversion, College Education, and Longevity of High-Ability Individuals

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    Using the 1922–1991 Terman Life-Cycle Study of Children with High Ability, I investigate the relationship between childhood noncognitive skills, college education, and longevity of a high-IQ population and find a strong relationship between college education and longevity for men. Conscientiousness and Extraversion are strongly related to longevity of men, even though their effects on education are, at best, weak. I demonstrate a number of behavioral mechanisms behind the estimated effects on longevity. I also find that men with higher levels of education and skills have superior health over the lifespan. For women of this historical cohort (born around 1910), who live at least as long as college-educated men, I find no evidence of a relationship between education, noncognitive skills, and longevity

    Early nomads of the Eastern Steppe and their tentative connections in the West

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    The origin of the Xiongnu and the Rourans, the nomadic groups that dominated the eastern Eurasian steppe in the late first millennium BC/early first millennium AD, is one of the most controversial topics in the early history of Inner Asia. As debatable is the evidence linking these two groups with the steppe nomads of early medieval Europe, i.e. the Huns and the Avars, respectively. In this paper, we address the problems of Xiongnu–Hun and Rouran–Avar connections from an interdisciplinary perspective, complementing current archaeological and historical research with a critical analysis of the available evidence from historical linguistics and population genetics. Both lines of research suggest a mixed origin of the Xiongnu population, consisting of eastern and western Eurasian substrata, and emphasize the lack of unambiguous evidence for a continuity between the Xiongnu and the European Huns. In parallel, both disciplines suggest that at least some of the European Avars were of Eastern Asian ancestry, but neither linguistic nor genetic evidence provides sufficient support for a specific connection between the Avars and the Asian Rourans.1. Introduction 2. The Xiongnu of Inner Asia and the Huns of European history 2.1. Historical and archaeological background 2.2. Historical linguistics 2.3. Population genetics 3. The Rourans of Inner Asia and the Avars of European history 3.1. Historical and archaeological background 3.2. Historical linguistics 3.3. Population genetics 4. Discussion and conclusio

    Socioemotional Skills, Education, and Health-Related Outcomes of High-Ability Individuals

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    We use the high-IQ Terman sample to estimate relationships between education, socioemotional skills, and health-related outcomes that include health behaviors, lifestyles, and health measures across the life cycle. By both focusing on a high-IQ sample and controlling for IQ in regression models, we mitigate ability bias due to cognitive skill. In addition, we control for detailed personality measures to account for socioemotional skills. We model skills using factor analysis to address measurement error and adopt a powerful stepdown procedure to account for multiple hypothesis testing. We find that among high-IQ subjects, education is linked to better health-related outcomes, in contrast to previous evidence. Conscientiousness, Openness, Extraversion, and Neuroticism are linked to various health-related outcomes across the lifecycle. Furthermore, we find that accounting for a comprehensive set of skills, measurement error, and multiple hypothesis testing not only provides greater confidence in several established relationships but also generates novel results

    The Rate of Return to the High/Scope Perry Preschool Program

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    This paper estimates the rate of return to the High/Scope Perry Preschool Program, an early intervention program targeted toward disadvantaged African-American youth. Estimates of the rate of return to the Perry program are widely cited to support the claim of substantial economic benefits from preschool education programs. Previous studies of the rate of return to this program ignore the compromises that occurred in the randomization protocol. They do not report standard errors. The rates of return estimated in this paper account for these factors. We conduct an extensive analysis of sensitivity to alternative plausible assumptions. Estimated social rates of return generally fall between 7-10 percent, with most estimates substantially lower than those previously reported in the literature. However, returns are generally statistically significantly different from zero for both males and females and are above the historical return on equity. Estimated benefit-to-cost ratios support this conclusion.early childhood intervention programs, compromised randomization, Perry Preschool Program, standard errors, cost-benefit analysis, rate of return, deadweight costs

    Analyzing Social Experiments as Implemented: A Reexamination of the Evidence From the HighScope Perry Preschool Program

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    Social experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. "Signicant" effects are often reported with p-values that do not account for preliminary screening from a large candidate pool of possible effects. This paper develops tools for analyzing data from experiments as they are actually implemented. We apply these tools to analyze the influential HighScope Perry Preschool Program. The Perry program was a social experiment that provided preschool education and home visits to disadvantaged children during their preschool years. It was evaluated by the method of random assignment. Both treatments and controls have been followed from age 3 through age 40. Previous analyses of the Perry data assume that the planned randomization protocol was implemented. In fact, as in many social experiments, the intended randomization protocol was compromised. Accounting for compromised randomization, multiple-hypothesis testing, and small sample sizes, we find statistically significant and economically important program effects for both males and females. We also examine the representativeness of the Perry study.early childhood intervention; compromised randomization; social experiment; multiple-hypothesis testing

    The Rate of Return to the High/Scope Perry Preschool Program

    Get PDF
    This paper estimates the rate of return to the High/Scope Perry Preschool Program, an early intervention program targeted toward disadvantaged African-American youth. Estimates of the rate of return to the Perry program are widely cited to support the claim of substantial economic benefits from preschool education programs. Previous studies of the rate of return to this program ignore the compromises that occurred in the randomization protocol. They do not report standard errors. The rates of return estimated in this paper account for these factors. We conduct an extensive analysis of sensitivity to alternative plausible assumptions. Estimated social rates of return generally fall between 7–10 percent, with most estimates substantially lower than those previously reported in the literature. However, returns are generally statistically significantly different from zero for both males and females and are above the historical return on equity. Estimated benefit-to-cost ratios support this conclusion.rate of return, cost-benefit analysis, standard errors, Perry Preschool Program, compromised randomization, early childhood intervention programs, deadweight costs
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