Stable isotopes and human diet in central western Argentina

Central western Argentina is the southern boundary of prehispanic maize in the archaeological record. This paper explores the stable isotope information from human bone (δ¹³C, from collagen and δ¹³C from apatite) and tooth (δ¹³C from enamel) samples in order to characterize the temporal and spatial trends of these isotopes and to understand them in terms of human diet. We analyzed 104 human individuals from the last 6000 years. Using the Kellner and Schoeninger (2007) model the results shows a high variation in human diet with few human individuals with a notably high significance of C₄ plants (probably maize) as an energy source and these samples have a chronology around ca. 1000 years BP. On the other hand a high variation in an individual’s dietary life history is shown by differences between δ¹³C collagen, apatite and enamel.     

The Role of Future Discounting in Subsistence Decisions: The Case of Hohokam Agave Bajada Cultivation

This article demonstrates the relevance of future discounting behavior to studies of prehistoric subsistence strategies. The case study of Agave spp. bajada cultivation among the Classic Period, a.d. 1150–1450, Hohokam of southern Arizona illustrates how slight discounting of future rewards can significantly alter agriculture investment strategies. Despite a higher kcal/hour return than maize agriculture, agave cultivation lessened or ceased in several communities during a time in which intensification would be predicted due to inferred subsistence stress. We surmise the decade-long maturation of agave made it unattractive relative to more immediate return resources in any context that presented risks to land tenure. The cessation of agave cultivation can be understood on two levels of explanation. The long-term investments required by agave and tendency to discount future rewards are the ultimate causes. Political and social instability during the tumultuous Classic period, causing increased insecurity in land tenure, are the proximal causes.     

Railways as a Factor of Change in the Distribution of Population in Spain, 1900–1970

Abstract

The central focus of this work is to test a new methodology to measure the impact of the railway on the distribution of population, in this case in Spain. To achieve this, it was necessary to previously integrate data relating to population and railway lines into a geographical information system. The result was a spatial database that includes population data from homogeneous census series obtained for the municipal scale and the evolution of the railway network in service at corresponding points in time. This allowed the authors to apply spatial-temporal analysis. By so doing, this work constitutes an analysis of a new methodology, as they used exploratory spatial data analysis and geographically weighted regression to detect spatial patterns and estimate the influence of the railway and distance from the coast on population change. The results obtained show that the influence of the railway was very pronounced in some areas, while in others it was just one of the factors that could explain major changes in population distribution.     

Evolution of the Territorial Coverage of the Railway Network and its Influence on Population Growth: The Case of England and Wales, 1871–1931

Abstract

The introduction of the railway network brought with it an unprecedented improvement in accessibility. In this work, the authors analyze the evolution of the territorial coverage of the railway network and its influence on the uneven distribution of population. To carry out this research, they used comparable data on total population obtained from census records relating to civil parishes of England and Wales, taken at 10-year intervals from 1871. The hypothesis that they wished to test was that good access to a railway station was related to significant increases in population. This exercise provides a better understanding of regional variations in population growth and allows the authors to identify current differences between urban and rural areas that have resulted from their historical evolution.     

The southernmost records of Anhingidae and a new basal species of Anatidae (Aves) from the lower–middle Miocene of Patagonia,Argentina

New bird fossils from the Santa Cruz Formation (lower–middle Miocene), Santa Cruz Province, Patagonia, Argentina, are described. They represent an indeterminate species of the extinct anhingid Macranhinga and a new genus and species of basal Anatidae Ankonetta larriestrai. The record of the giant darter Macranhinga constitutes the southernmost record for the family, and expands the known stratigraphic range of the genus, previously restricted to the upper Miocene. Based on an analysis of the fossil anhingid record from South America, we hypothesize that giant darters disappeared from South America in the early Pliocene due to climatic deterioration, regression of marine and freshwater environments, the arrival of placental carnivorous mammals, and also probably by competition with phalacrocoracid cormorants. The new anatid Ankonetta is based on an incomplete but informative tarsometatarsus, with superficial similarities to extant Dendrocygna. A brief overview of several fossil ducks from the Patagonian Cenozoic concludes that most pre-Pliocene examples belong to non-anatine taxa, indicating that plesiomorphic ducks were the dominant anseriforms in those times, a pattern also evident on other continents.     

Microscopy in Camillo Golgi's Times

The research performed by Camillo Golgi in histology and pathology dates from 1865, the year in which he obtained his MD degree, to 1923, when his last scientific article was published. Beginning in the mid-1855s, microscope manufacturers in Europe started producing objectives based on the principle of immersion introduced in 1847 by Giovan Battista Amici. The immersion objectives greatly improved the resolution of microscopic observations at high magnifications. From 1860 to 1872, technological improvements in microscope optics and the practicality of their use provided a larger community of investigators effective tools needed to study the structure of the nervous system. This progress in microscopy was associated with the application of new histological techniques, mastered by the chromoargentic reaction introduced by Golgi in 1873. In 1872, further progress in microscopy stemmed from the application of notions of applied physics to the production of microscope optics. These developments in microscopy will be briefly reviewed here.