52 research outputs found
Reconstructing breastfeeding and weaning practices in the Bronze Age Near East using stable nitrogen isotopes.
OBJECTIVES: Breastfeeding and childhood diet have significant impact on morbidity and mortality within a population, and in the ancient Near East, it is possible to compare bioarchaeological reconstruction of breastfeeding and weaning practices with the scant textual evidence. MATERIALS AND METHODS: Nitrogen stable isotopes (δ15 N) are analyzed here for dietary reconstruction in skeletal collections from five Bronze Age (ca. 2,800-1,200 BCE) sites in modern Lebanon and Syria. We employed Bayesian computational modeling on cross-sectional stable isotope data of collagen samples (n = 176) mainly from previous studies to test whether the bioarchaeological evidence aligns with the textual evidence of breastfeeding and weaning practices in the region, as well as compare the estimated weaning times to the global findings using the WARN (weaning age reconstruction with nitrogen isotope analysis) Bayesian model. RESULTS: Though the Near East sites in this study had different ecological settings and economic strategies, we found that weaning was introduced to the five sites at 0.5 ± 0.2 years of age and complete weaning occurred around 2.6 ± 0.3 years of age on using the WARN computational model. These weaning processes are within the time suggested by historical texts, though average estimated weaning age on the Mediterranean coast is later than inland sites. DISCUSSION: Compared globally, these Near Eastern populations initiated the weaning process earlier but completed weaning within the global average. Early initial weaning may have created short spacing between pregnancies and a high impact on demographic growth within these agricultural populations, with some variation in subsistence practices accounting for the inland/coastal discrepancies
How old are you now? A new ageing method for nonadults based on dental wear
The main aim of this study is to present a novel method of nonadult (ca. 1–19 years) age‐at‐death estimation using the dental wear of deciduous, mixed deciduous‐permanent, and permanent dentitions, including the incisors, canines, premolars, and first and second molars. The stage‐based method is derived from degrees of dental wear in known‐age (n = 39) and estimated‐age (n = 11) nonadults containing 951 teeth from the predominately 19th century cemetery of Middenbeemster, The Netherlands. The need for such a method is warranted in cases where dental development and/or eruption cannot be assessed for age‐at‐death estimation. As well, by establishing a baseline for normal age‐related nonadult tooth wear, users may better document wear that could be due to extramasticatory behaviours. The regression analysis reveals a strong quadratic correlation—F(2, 47) = 555.1, p R2 = .95, standard error of the estimate = 1.14, residual sum of squares (RSS) = 68.89, predicted residual error sum of squares (PRESS) = 77.67—between age and wear and multivariate adaptive regression splines (R2 = .95, generalised cross validation = 1.67, RSS = 67.68, PRESS = 89.34), which are used to develop an R‐package that users may employ to estimate age‐at‐death from dental wear. The accuracy of this method (78–98%) is evaluated using leave‐one‐out cross‐validation. Analyses of males versus females, deciduous versus permanent, upper versus lower, and anterior versus posterior teeth revealed no apparent reason to warrant separate methods for these groups of separated dentitions. This method fills a disciplinary gap in the understudied area of deciduous and nonadult dental wear and hopes to stimulate much future research. With the R‐package, we also provide the foundation and framework for the development of additional reference populations across different spatiotemporal contexts, to make the method more widely applicable. Bioarchaeolog
Capacity of finite systems of elements in Banach algebras
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On the projection property of approximate point joint spectra
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Time to replacement passengers at bus stations in Bydgoszcz
W artykule przedstawiono wyniki obserwacji czasu wymiany potoków pasażerskich na przystankach autobusowych na terenie Bydgoszczy. Ponadto przeanalizowano czynniki, które mogą mieć bezpośredni i pośredni wpływ na długość trwania wymiany podróżnych wysiadających z pojazdu oraz podróżnych wsiadających do pojazdu.The article presents observation results of time to replacement passengers at bus stations in Bydgoszcz. In addition the factors, which may have an impact on the length of the duration of replacement passengers getting off vehicle and getting on vehicle were analyzed
Existence theorems for -solutions of the Hammerstein integral equation in Banach spaces
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Much ado about nothing: assessing the impact of the 4.2 kya event on human subsistence patterns in northern Mesopotamia using stable isotope analysis
The effects of the 4.2 kya climatic event on northern Mesopotamia have been the subject of significant scholarly debate, with the notion of a megadrought that forced local populations to migrate attracting particular attention. Here, the authors analyse stable carbon (δ13C) and nitrogen (δ15N) isotopes in human tooth and bone samples to assess trends in subsistence practice at three sites in Syria before, during and after the presumed megadrought event. Despite the proximity of the sites, isotopic differences between them are more significant than diachronic change. Combined with other archaeological evidence, these results indicate a continuity in subsistence patterns, with no indication of disruption associated with the 4.2 kya event.- The 4.2 kya event in northern Mesopotamia - Reconstructing subsistence using bone and tooth collagen δ13C and δ15N values - Materials and methods - Results - Discussion - Conclusion
Markov model of the operation and maintenance process of farm tractors
Efektywna i racjonalna analiza złożonych procesów eksploatacji obiektów technicznych wymaga zastosowania różnego rodzaju metod modelowania, w tym modeli matematycznych i symulacyjnych. W badaniach do opisu rzeczywistego procesu eksploatacji ciągników rolniczych opracowano zdarzeniowy model procesu eksploatacji, a następnie zbudowano model matematyczny z zastosowaniem teorii procesów Markowa. Na podstawie otrzymanych wyników dokonano analizy rozpatrywanego procesu eksploatacji obiektów technicznych.An effective and rational analysis of complex processes of technical object operation and maintenance requires the use of various types of modeling methods, including mathematical and simulation models. In this paper, in order to describe the actual process of farm tractor operation and maintenance, an event model of the operation and maintenance process was developed, and then a mathematical model of this process was built using the theory of Markov processes. On the basis of the obtained results, the considered operation and maintenance process was analyzed
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