Geochemical impacts to prehistoric iron-rich siliceous artifacts in the nearshore coastal zone

In the Middle Atlantic region of the United States, landscapes drowned by sea level rise contain scores of prehistoric archaeological sites. These sites provide archaeologists with a rare opportunity to investigate various geologic processes. During the transition from a terrestrial to an offshore setting, the materials associated with an archaeological site are exposed to a series of geochemical processes inherent to the formation of tidal marsh. The duration of the geochemical exposure to tidal marsh is largely dependent on the rate of marine transgression. Here we describe the stages associated with the sulfidization and sulfuricization scheme and the impact to iron-rich lithic artifacts from naturally drowned archaeological sites. Sulfidization and sulfuricization should also impact buried archaeological materials as a result of anthropogenic dredge spoil dumping and the creation of man-made tidal marshes along modern coastlines. Our results indicate that the surfaces of an iron-rich artifact, as well as its interior are visually and geochemically altered by prolonged exposure to the anaerobic conditions of a tidal marsh. Not only should researchers be cautious about making lithic material identification on artifacts found within coastal tidal marsh areas, but museum curators should be aware of the damaging impact of long-term aerobic storage. The geochemical tidal marsh scheme that has altered or corroded iron-rich lithic artifacts in the nearshore zone is an expression of a process that has impacted numerous earlier prehistoric sites currently located on the continental shelf or beneath the coastal estuaries around the world.     

Industry Influence in Stakeholder‐Driven State Climate Change Planning Efforts

Drawing from the literature on public participation and stakeholder collaboratives, this article investigates the influence of power and wealth, as well as political and economic context on the output of stakeholders advisory committees convened to formulate state greenhouse gas (GHG) mitigation policies. Using small sample regression techniques, we analyze the outputs of stakeholder groups in 18 states that have completed Climate Action Plans to reduce GHGs. We find that an increase of 1 percent in the number of energy industry representatives that participate in Climate Action Councils significantly predicts a 4 percent reduction of GHG mitigation targets for the energy sector. More surprisingly, the results also show that where the utilities represent a larger share of the state economy, the Climate Action Plans identify more aggressive GHG reduction goals for the energy sector. We also find that the political orientation of the executive of the state is not correlated with GHG mitigation requirements for the energy sector, suggesting that GHG mitigation is less partisan at the state level than in Washington, DC. We find no evidence that state wealth is associated with GHG mitigation requirements. Finally, we suggest additional research needed to clarify the role of stakeholder participation processes in the evolving arena of climate change policy.     

Nonparametric Estimation of the Spatial Connectivity Matrix Using Spatial Panel Data

We use moments from the covariance matrix for spatial panel data to estimate the parameters of the spatial autoregression model, including the spatial connectivity matrix W. In the unrestricted spatial autoregression model, the parameters are underidentified by one when W is symmetric. We show that a special case exists in which W is asymmetric and its parameters are exactly identified. If the panel data are stationary and ergodic, spatially and temporally, the estimates of W and the spatial autoregression coefficients are consistent. Spatial panel data for house prices in Israel are used to illustrate this methodology. Los autores usan momentos de una matriz de covarianza para datos panel espaciales para estimar los parámetros del modelo de autoregresión espacial (spatial autoregressive model), incluyendo la matriz de conectividad (o de ponderación) espacial W. En el modelo de autoregresión espacial sin restricciones, los parámetros están sub‐identificados por un valor de uno en los casos que la matriz W es simétrica. Los autores demuestran que existe un caso especial en el cual la matriz W es asimétrica y sus parámetros tienen cálculo exacto. Si los datos panel son estacionarios y ergódicos, espacial y temporalmente, los estimados de W y el coeficiente de autoregresión espacial son consistentes. Para ilustrar la metodología propuesta, los autores usan datos‐panel espaciales de precios de vivienda en Israel. 本文通过采用空间面板数据的协方差矩阵对包含空间相关矩阵W的空间自回归模型进行参数的矩估计。在无约束空间自回归模型中,W是对称矩阵时,参数可由其估计得到。本文展示了一种W是对称矩阵且其参数能够被精确估计的特殊情况。如果面板数据在时间与空间特征上具有平稳性和遍历性,那么W和空间自回归参数的估计是一致的。最后,针对以色列住房价格的空间面板数据采用此方法进行实证研究。     

Disentangling long bones of foxes (Vulpes vulpes and Alopex lagopus) from arctic archaeological sites

To discern the presence of two anatomically close species within an archaeological assemblage is always a problem for the analyst. A particularly interesting case is the distinction between the red fox (Vulpes vulpes) and the arctic fox (Alopex lagopus), which is often determined using non-rigorous criteria and producing results that must be regarded with caution. Classical methods for separating these two species and determining sexual dimorphism, and eventually the sex ratio, such as analyses using uni- and bivariate plots, are based on arbitrarily fixed limits between sexes. In this text, a more robust statistical method termed mixture analysis (MA) is used to determine the species of limb bones from foxes. First, the MA is applied to a sample of each species using metric data taken from a collection of present-day fox skeletons. Afterwards, the MA is applied to archaeological samples dated to the Dorset period and retrieved from the Tayara site (near Salluit, South Hudson Strait, Nunavik). The results clearly demonstrate that the greatest length (GL) of long bones, especially the humerus and tibia, is the best measurement for distinguishing the species, followed by the distal breadth and the proximal breadth; and that GL is better suited for sexing foxes. The results of MA applied to the Tayara site collection lead to the conclusion that the red fox is present along with the arctic fox among the assemblage, and that there is no fox body size change during the last two millennia in the Eastern Arctic.     

Tuberculosis on the north coast of Peru: skeletal and molecular paleopathology of late pre-Hispanic and postcontact mycobacterial disease

This paper examines skeletal and ancient DNA evidence in the study of suspected tuberculosis infection in the late pre-Hispanic and Colonial-era Lambayeque Valley Complex, north coast Peru (A.D. 900–1750). We integrate information on macroscopic lesion characteristics and distribution, radiographic and CT scan imagery, and analysis of Mycobacterium tuberculosis complex rpoB and IS6110 ancient DNA (aDNA) sequences. Destructive lesions were observed in the vertebral bodies of three precontact indigenous adult males, one colonial adolescent female, and in the cranium of a Colonial-period subadult. Assessment of lesion morphology and distribution led us to consider multiple diseases, but tuberculosis represents the most likely diagnostic option in all individuals. DNA was poorly preserved in all samples, but an IS6110 sequence was amplified in one precontact individual consistent with macroscopic diagnosis. These findings expand the geographic and temporal extent of tuberculosis to the late pre-Hispanic and Colonial north coast of Peru to highlight potential synergisms between diet, settlement patterns, and the evolution of Andean tuberculosis before and after European conquest. Moreover, this study helps focus several key questions in Andean tuberculosis research, including possible reassessment of the presence of the IS6110 sequence in the pre-Columbian Americas. Methodological considerations include differential diagnosis – especially with incomplete skeletons – and limitations of aDNA studies underscoring an approach integrating macroscopic, radiographic, and molecular lines of evidence in the paleopathological investigation of one of humankind’s most devastating and destabilizing diseases.