An improved PCR method for endogenous DNA retrieval in contaminated Neandertal samples based on the use of blocking primers

Neandertal skeletal remains are usually contaminated with modern human DNA derived from handling and washing of the specimens during excavation. Despite the fact that the distinct Neandertal haplotypes allow the design of specific primer pairs, for instance in most of the mitochondrial DNA (mtDNA) hypervariable region 1 (HVR1), the human contaminants can often outnumber the endogenous DNA, thus preventing a successful retrieval of Neandertal sequences. We have developed a novel PCR method, based on the use of blocking primers that preferentially bind to modern human contaminant DNA and block their amplification, and greatly improve the efficiency of Neandertal DNA retrieval. We tested the method in four El Sidrón Neandertal samples (two teeth and two bone fragments) with different contamination levels and taphonomic conditions, and we have been able to significantly increase the Neandertal yield from figures around 25.23% (5–69.6%) up to 90.18% (75.3–100%).     

Symposium international Galileo 2001 Tenerife, February 19–23, 2001

Vie Scientifique

Symposium international Galileo 2001 Tenerife, February 19–23, 2001     

The nation against the State: The Irish question and Britain‐based anarchists in the Age of Empire

This paper discusses the relationship between early anarchism and republican/nationalist ideas. We will focus on the case of British‐based activists grouped around the journal Freedom and their engagement with Irish nationalism during the Age of the Empire. Freedom, founded in 1886, was the most important anarchist journal of the English‐speaking anarchist–communist networks at the time and was the main editorial reference for the worldwide community of anarchist activists, mostly exiled, who resided in London at that time. Extending current interdisciplinary literature on transnational anarchism, we argue that anarchist views of nations, while rejecting the novel notion of the nation‐state, were associated with anti‐colonial struggles and with republican anti‐monarchical and egalitarian notions. Based on primary sources, we discuss the intersections between these Britain‐based anarchists and anti‐colonial Irish radicals, by engaging both with their writings and their international networks of solidarity, thus exploring the complex intermingling of anarchism, anti‐colonialism, and republicanism.     

Migration in the Nile Valley during the New Kingdom period: a preliminary strontium isotope study

The value of strontium isotope analysis in identifying immigrants at numerous archaeological sites and regional areas has been demonstrated by several researchers, usually by comparing ⁸⁷Sr/⁸⁶Sr values of human tooth enamel and/or bone with the local strontium isotope signature determined by faunal and environmental samples. This paper examines the feasibility of using ⁸⁷Sr/⁸⁶Sr ratios to investigate residential mobility in the Nile Valley region, specifically at the New Kingdom period (∼1050–1400 BC) archaeological site of Tombos (ancient Nubia). Archaeological and textual information regarding this period indicates that immigrant Egyptians and local native Nubians were likely interacting at this site during a period of Egyptian colonial occupation. The results of this study suggest that non-local individuals may be distinguished from locals using ⁸⁷Sr/⁸⁶Sr values and that colonial agents in the Tombos population were probably both local native Nubians and immigrants.     

Using Spatial Filters and Exploratory Data Analysis to Enhance Regression Models of Spatial Data

Residual spatial autocorrelation is a situation frequently encountered in regression analysis of spatial data. The statistical problems arising due to this phenomenon are well‐understood. Original developments in the field of statistical analysis of spatial data were meant to detect spatial pattern, in order to assess whether corrective measures were required. An early development was the use of residual autocorrelation as an exploratory tool to improve regression analysis of spatial data. In this note, we propose the use of spatial filtering and exploratory data analysis as a way to identify omitted but potentially relevant independent variables. We use an example of blood donation patterns in Toronto, Canada, to demonstrate the proposed approach. In particular, we show how an initial filter used to rectify autocorrelation problems can be progressively replaced by substantive variables. In the present case, the variables so retrieved reveal the impact of urban form, travel habits, and demographic and socio‐economic attributes on donation rates. The approach is particularly appealing for model formulations that do not easily accommodate positive spatial autocorrelation, but should be of interest as well for the case of continuous variables in linear regression.     

Analysis of the collapse mechanisms of medieval churches struck by the 2016 Umbrian earthquake

The 2016 Umbrian earthquake caused the collapse of several medieval churches, while it was noted that ordinary buildings only reported moderate or little damage. Researchers and technicians are looking to these religious constructions with the aim of understanding their structural behavior under seismic action. Depending on the direction of the seismic action, the typical collapse mode was the overturning of the side walls or of the church façade. This often produced the collapse of the roof structure. In many situations, the overturning was facilitated by a weak connection between the load-bearing walls. In this article, the collapse modes of three mediaeval churches are investigated. The article goes into some detail about what considerations are relevant when analyzing a historic masonry construction. The churches object of this study are located in Campi, a hamlet of Norcia, Italy. Between 2000 and 2004, a research team from the Technical University of Milan in collaboration with the Italian Ministry of Culture carried out an extensive investigation on the historic buildings of Campi, providing interesting data about the maintenance level and a summary of the structural state of the churches. These data were used in this article for a critical analysis of the causes of collapse, performed in combination with numerical simulations of the global behavior and local instability.     

Determination of Shear Strength of Masonry Panels Through Different Tests

This study addresses the problem of evaluation of strength of masonry walls. In-plane behavior of masonry panels has been studied under monotonic diagonal-compression and shear-compression loading in quasi-static test facility. The results of 35 laboratory and in situ tests are analyzed to show that in the case of the diagonal compression test results are lower than the strength of masonry walls evaluated trough the shear-compression test, highlighting the problem of choosing the test which best simulates to the real behavior of the masonry when stressed by lateral loads. A presentation is also given of the results of a F.E. investigation for shear strength evaluation of masonry walls. F.E. modeling non-linear procedure was used for the representation of masonry panels. The numerical simulations are compared with experimental results and the reliability of the different finite element models is discussed, thus confirming the different shear strength values measured in the experimental campaign.