Recovery and analysis of human genetic material from mummified tissue and bone

Using sensitive techniques of molecular biology, we have been able to demonstrate the presence of genomic material of human origin in samples of mummified human tissue and bone from selected archaeological sites in Greenland. This result has far-reaching consequences for both evolutionary and archaeological studies of past human populations.     

Optimal Control of Accelerations in a Base-Isolated Building using Magneto-Rheological Dampers and Genetic Algorithms

This article presents a numerical study aimed at improving effectiveness of the isolation system of an actual building by adding magneto-rheological (MR) dampers that act in parallel to the existing rubber bearings (RB). The building itself is modeled with uniaxial elastic elements. Additional elements that include the RBs and the MR dampers are added at the base of the building and two different genetic algorithms are used to optimize operation of the MR dampers. Maximum acceleration and relative displacement at the top of the building are taken as the variables to be minimized. Records of destructive earthquakes are used as input. A comparison is made between the building responses with RB and the one with the additional control system.     

Linking Essentialist and Constructivist Ethnicity

Abstract

This article argues that the essentialist and the constructivist positions within theories of ethnicity are in fact compatible if one introduces a concept here called “internalized fluid capacities”, connoting that which is inherently (genetically) dispositional – and in that sense biologically “anticipated” – but which remains to be developed into observable social characteristics through sociocultural impact. This perspective is based on the genetic capacity to mold or “instruct” the development of an organism from its embryonic state and onwards by using prior stages as points of departure for further instructions. In this way, certain fluid capacities become imprinted in individuals and collectivities through reinforcing interaction with the ambient society. These capacities may then harden and develop into apparent “essentials”, forming a group's collective self-image. The article concludes with the suggestion that this explanatory model can be usefully applied to the debate around Swedish governmental definitions of Saamihood.     

Genetic sexing to determine the optimal discriminant functions for the analysis of archaeological remains from El Hierro (Canary Islands)

A correct sex assignment of a given bone or bone fragment is of paramount importance for the archaeologist, anthropologist and in forensic medicine. Discriminant functions, combining several anthropometric measurements obtained from individuals with known sex are useful tools for this purpose, but it is essential to know exactly the sex from which the measures are obtained. This is an easy task in modern populations, but it is problematic in ancient ones, since even when the entire skeleton is available, diagnosis of sex is not 100% accurate. Sexing by genetic methods by amplifying the first intron of the amelogenin gene constitutes a much more accurate method for sexing bones and may be the gold standard for further elaboration of discriminant functions which may serve for sexing new bones dug up in future excavations. With this aim we have genetically sexed 52 (out of 59) tibiae belonging to the prehispanic population of El Hierro, in the Canary Islands, identifying 18 women and 34 men, and then, performed discriminant functions combining several anthropometric variables. These functions show a high accuracy in sex diagnosis (94.2%; area under ROC curve = 0.954 with the best of the functions), so that they allow correct sexing of tibiae or tibiae fragments (only proximal third, distal third or midshaft). Thus, genetic sexing obviates the problem of finding an accurate gold standard for the elaboration of discriminant functions for ancient bones. This method could be applied to other populations of different antiquity and different ethnicity.     

On-line Model Updating in Hybrid Simulation Tests

Hybrid simulation has emerged as a relatively accurate and efficient tool for the evaluation of structural response under earthquake loading. In conventional hybrid simulation the response of a few critical components is obtained by testing while the numerical module is assumed to follow an analytical idealization. Where there is a much larger number of analytical components compared to the experimental parts, the overall response may be dominated by the idealized parts hence the value of hybrid simulation is diminished. It is proposed to modify the material constitutive relationship of the numerical model during the test, based on the data obtained from the physically tested component. An approach based on genetic algorithms is utilized as an optimization tool to identify the constitutive relationship parameters used in updating the numerical model. The proposed model updating approach is verified through two analytical examples of steel and reinforced concrete frames. The results show the effectiveness of the updating process in minimizing the errors, compared to the assumed exact solution.     

人类基因工程面临的道德问题

基因工程已经用于人类克隆并因此引起了极大的关注和争议。比如道德灾难、基因歧视以及转基因产品的不确定性。因此人类克隆应该受到限制,用于治疗目的的人类克隆应该严格受控。     

Physical and Numerical Approaches for the Optimal Insertion of Seismic Viscous Dampers in Shear-Type Structures

This article presents the results of an exhaustive parametric analysis which compares the performances offered by various systems (which lead to both classical and non classical damping matrices) of added viscous dampers in shear-type structures. The aim of the research work here presented is the identification of the system of added viscous dampers which maximizes the dissipative properties under an equal “total size” constraint. The choice of the systems of added viscous dampers considered in the comparison is carried out both using a numerical approach (based upon the use of genetic algorithms) and a physically based approach (based upon the properties of classically damped systems). The comparison is carried out through the numerical evaluation of the dynamic response of representative shear-type structures to both stochastic and recorded earthquake inputs. The results obtained using both approaches indicate that a damping system based upon the mass proportional damping component of the Rayleigh viscous damping matrix (referred to as MPD system) is capable of optimizing simultaneously a number of different performance indexes, providing the best “overall” damping performances. The MPD system is characterised by viscous dampers (a) which connect each floor to a fixed point and (b) which are sized proportionally to the corresponding floor mass.     

发生学方法与历史研究

发生学方法兴起于自然科学研究领域,随后被人文社会科学研究领域所采用。唯物史观和唯物辩证法使这一方法走向科学,从而形成了具有普遍意义的科学的马克思主义发生学方法。它是对现实及其发生前提和发生过程进行研究的方法,具有科学性、革命性和实践性特征,在马克思主义的历史研究方法体系中处于支配地位。然而,这并非意味着它是历史研究的唯一方法。这对我们加深理解唯物史观与历史学理论方法之间的关系,具有重要启示意义。     

Further developments in molecular sex assignment: a blind test of 18th and 19th century human skeletons

The identification of sex in human remains recovered from archaeological locations is important in order to understand the social and biological structure of past societies, and to reconstruct past population demographic events. Sex determination is usually based on morphological traits of the skeletons, with the drawback that most methods do not apply to juveniles and require well preserved remains. In cases where morphological methods cannot be used, or are ambiguous, methods of molecular sexing systems are an alternative. In this methodological study we tested and validated the accuracy and usefulness of a molecular sexing method based on the amelogenin gene using pyrosequencing. We did this in a double blind study of documented 18th and 19th century human remains.     

Using spatial analysis to estimate depopulation for Native American populations in northeastern North America,AD 1616–1645

Eight years ago, Ramenofsky et al. (2003) characterized the discussion of the impact of Old World diseases on Native American populations as almost exclusively historical in nature. They specifically argued for the application of more evolutionary, genetic, and epidemiological theory to research into this topic. We agree with their assessment and further suggest that such research would greatly benefit from spatial analyses of disease spread as well. Using trend surface analysis of existing ethnohistorical and archaeological data pertaining to population sizes and disease events, we examine the spatiotemporal dimensions of 17th century depopulation in northeastern North America. The subsequent results allow us to predict possible depopulation rates for populations with very little demographic data. Further, our use of biological, historical, and cultural data to interpret the results represents an attempt to provide a more complex explanation for the variability in cultural survivability across the region and several possible avenues for productive future research. We believe research like this can significantly improve our understanding of how Old World diseases affected historic Native American populations and cultures and continue to impact them today.