Radiocarbon dating of prehistoric hearths in alpine northern Sweden: problems and possibilities

The chronology of prehistoric Sami settlement sites has previously been established by conventional radiocarbon dating of bulk charcoal samples associated with hearths from sunken hut floors (stállo-foundations). Here we present results of a comprehensive dating exercise of stállo-foundations in the alpine area of northern Scandinavia using Accelerator Mass Spectrometry (AMS) radiocarbon dating of charcoal. Over a 3 km² study area, AMS calibrated ages of hearth charcoal from 22 stállo-foundations across 12 sites securely date these features to between cal. AD 640 and AD 1180. Only small variations in age were found between charcoal samples from different areas of a given hearth. Statistical analysis of all the charcoal AMS radiocarbon dates obtained reveals that 12 stállo-foundations across nine sites are contemporaneous and date to the Viking Period (AD 800–AD 1050). The tightly constrained AMS-based chronology of stállo-foundations contrasts with the existing chronology based on conventional radiocarbon analysis, which places these features within a significantly greater time-frame of between AD 600 and AD 1900, with most dates ranging between AD 800 and AD 1350.This discrepancy is likely to result from the necessity of collecting composite hearth charcoal particles, which may originate from different phases of occupation, in order to achieve the required final carbon content for conventional radiocarbon analysis. We argue that the new AMS-based radiocarbon chronology of stállo-foundations presented here supersedes the existing chronology based on conventional (Gas Proportional counting) radiocarbon analysis and we advocate the use of AMS radiocarbon dating in future hearth investigations.     

Reproduction rates in multiregion modeling systems for HIV / AIDS

The persistence of HIV/AIDS has seen a revival of academic interest in the development of modeling systems to assist understanding the population dynamics of this infection. Moreover, it has become increasingly recognized that a key component of these systems for interpreting disease prevention is their reproduction rate, which provides an indication of whether an epidemic might start in a community described by a particular set of epidemiological characteristics. The properties of these rates have been explored in detail for models of a single risk behavior but not for multiregion formats that allow for the transfer of infection between geographical units. Therefore, in this paper I derive reproduction rates for a multiregion HIV/AIDS model together with their associated critical thresholds that estimate the minimum population of susceptibles necessary for an epidemic to begin. These statistics are interpreted for a simplified global setting representing regional variations in the potential onset of HIV/AIDS. In the discussion I examine the potential applicability of these results to understanding HIV/AIDS prevention.     

Final Paleolithic and Mesolithic Research in Reunified Germany

During the past decade research into the German Final Paleolithic and Mesolithic has experienced an important revival. One clear sign of this renewed interest in the periods are the annual meetings of the Arbeitsgruppe Mesolithikum (Mesolithic Working Group) which have taken place every spring since 1992. At these meetings, which take place at changing venues, topical themes of Final Paleolithic and Mesolithic interest are presented by informal lectures and it is also possible to study regional collections (artifacts, raw materials) at first hand. Numerous contributions were subsequently published together in one volume (Conard and Kind (1998) Aktuelle Forschungen zum Mesolithikum/Current Mesolithic Research, Mo Vince, Tübingen). The present paper intends to complement that collection of papers with a synthesis of developments and perspectives and to present recent research highlights in the German Final Paleolithic and Mesolithic, together with a comprehensive bibliography, to a wider international audience.     

An Osteobiography of a 19th‐Century Dog from Toronto,Canada

A 19^th‐century dog burial uncovered from a historical homelot in Toronto, Canada, provided a unique opportunity to reconstruct the individual's osteobiography. Of particular interest are the dog's very large size and a suite of skeletal pathologies. Recovery of a nearly complete skeleton combined with the use of X‐rays and micro‐computed tomography (micro‐CT) allowed for a discriminating differential diagnoses. Stable isotope analyses were applied to investigate questions of diet. Results reveal an individual who suffered greatly from disease towards the end of his life and hint at its owners attitudes towards dogs. The interdisciplinary approach applied to this case study highlights the potential information obtainable from pet burials. We argue that better analyses and reporting of pet burials will help address research questions targeting broader themes related to human–animal relationships. Copyright © 2015 John Wiley & Sons, Ltd.     

EMERGENCE OF LEAPFROGGING FROM RESIDENTIAL CHOICE WITH ENDOGENOUS GREEN SPACE: ANALYTICAL RESULTS

Leapfrog development is a typical form of sprawl. This paper aims at analyzing the existence, size, and persistence of leapfrogging in a dynamic urban economic model with endogenous green amenities. We analyze whether incoming households choose to settle at the fringe of the city or to jump further away depending on their preferences and the structure of the city. We first provide an analytical treatment of the conditions and characteristics under which a first leapfrog occurs and show how the optimal choice is affected by the size of the city, income, commuting costs, as well as the size of the area where green amenities are considered. We then study how further leapfrogging and multiple urban rings may appear and be maintained in the long‐run equilibrium, and how infill processes take place through time.     

TAXATION AND INTERNAL MIGRATION—EVIDENCE FROM THE SWISS CENSUS USING COMMUNITY‐LEVEL VARIATION IN INCOME TAX RATES*

ABSTRACT We investigate the relationship between income tax rate variation and internal migration for the unique case of Switzerland, whose system of determining tax rates primarily at the community level results in enough variation to permit analysis of their influence on migration. Specifically, using Swiss census data, we analyze migratory responses to tax rate variations for various groups defined by age, education, and nationality/residence permit. The results suggest that young Swiss college graduates are most sensitive to tax rate differences, but the estimated effects are not large enough to offset the revenue‐increasing effect of a rise in tax rate. The migratory responses of foreigners and other age‐education groups are even smaller, and reverse causation seems negligible.