Effect of organic and inorganic consolidation agents on Tlaltecuhtli monolith

A huge monolithic piece corresponding to the first years of the sixteenth century has been discovered in Mexico City. It represents the earth goddess Tlaltecuhtli. The preservation of such a magnificent piece is imperative. Therefore, the surface has to be characterized and the interaction of consolidants with the rock has to be understood.Some of the consolidation methods are impregnation of the mineral with nopal or silicic acid derivatives. In this work we compare the physico-chemical effects of organic and inorganic consolidants. Original and impregnated samples are characterized with a series of original techniques: X-ray diffraction, nuclear magnetic resonance, nitrogen adsorption and small angle X-ray scattering. Fractal dimension, specific surface area and pore size distribution clearly differentiated the samples. The organic materials, nopal gum or slobber, cover the mineral particles with a smooth layer. The KSE solutions react and lead to microporosity.     

3D modelling of magnetic data from an archaeological site in north-western Tlaxcala state,Mexico

In Archaeology, geophysical methods had been applied usually in a qualitative form, limited only to the use of filters that enhance the data display. The main objective in this work is the implementation of a modelling technique that allows us to reconstruct the geometry of buried bodies and the determination of their depths. This is done by means of the estimation of the magnetic moments of archaeological objects using a three-dimensional mesh of individual magnetic dipoles using the least squares method and the singular value decomposition of a weighted matrix to solve the linear problem. The distribution and shape of the underlying archaeological remains can be inferred. This methodology was applied to an archaeological site called Los Teteles de Ocotitla, in the state of Tlaxcala, Mexico. A high-resolution magnetic prospection was carried out in three selected areas (terraces). The most important total field anomalies found on each area were inverted, obtaining results that were corroborated by archaeological excavations. This investigation demonstrates the potential of quantitative geophysical methods for the characterization of archaeological structures, in extension and in depth.     

The Transformation of Retail Markets in Lisbon: An Analysis through the Lens of Retail Gentrification

The relationship between cities and retail is strong and historical. This article focuses on the analysis of traditional retail markets, a retail concept that has lost its relevance in previous decades. However, more recently there has been a reversal of this trend following increased interest in the rehabilitation of these markets. This reinvestment follows the divestment stage and is characterised by the active role that private interests play in the management and operation of these retail precincts. This evolutionary process challenges the capacity of traditional retailers to continue their operations in these markets and the ability of disadvantaged customers to continue shopping there. Furthermore, this development may be indicative of retail gentrification. In this article, the ongoing process of market rehabilitation in Lisbon is analysed to determine whether evidence of retail gentrification has occurred. The use of case studies forms a significant part of the methodology. In addition, eleven retailers were interviewed in three traditional retail markets in Lisbon. The article concludes that direct displacement did not occur in the markets studies. However, because of the divestment in these retail precincts, indirect displacement did affect several retailers.     

SPATIAL SCOPE OF A MODERN TRANSPORT TECHNOLOGY

This paper studies the endogenous choice of transport technology, “traditional” versus “modern,” by a shipper. Although the “modern” technology is characterized by higher fixed costs and a higher speed of transport, it is chosen for intermediate distances, rather than to long distances. The reason is that, when the shipper switches to the “modern” technology, the industrial firm changes production from the home to the foreign city. Thus, the demand for transport decreases proportionally to the distance between the home and foreign city. For long distances, revenue from transportation becomes so low that the “modern” technology does not break even.     

A Roman Skeleton with Possible Treponematosis in the North‐East of the Iberian Peninsula: A Morphological and Radiological Study

The main goal of this paper is to describe and discuss pathological lesions observed in a Roman skeleton (between 2^nd and 3^rd century AD) from the north‐east region of the Iberian Peninsula (St Nicasi 18–24 site. Gavà, Barcelona), which may be compatible with treponematosis. Most of the skeleton, with the exception of the neurocranium, was recovered. Only the left tibia was affected, whereas the rest of the recovered skeletal remains were unaffected. Macroscopic examination revealed a male individual between 25 and 30 years of age at death with a sabre‐shaped left tibia. The proximal half of the diaphysis was pitted and the bone overall enlarged. The surface of the tibia showed occasional vascular impressions where, in some instances, small raised plaques of new bone appeared to bridge over them, specifically in the most affected area of the proximal half of the tibia. No destructive lesions were observed. Radiographic examination and gross inspection at the cross section of the tibia showed encroachment into the medullary cavity of coarse cancellous bone and cancellization of the cortex. The observed lesions indicate that the tibia was affected by a chronic infectious disease. Differential diagnoses were considered, and these included other infectious diseases, fibrous dysplasia, Paget's disease, chronic varicose ulcers affecting bone and trauma, with the conclusion that the disease affecting the tibia could have been treponematosis. This could be significant in the history of the treponematoses being one of the oldest examples of treponematosis in pre‐Columbian Europe. Copyright © 2011 John Wiley & Sons, Ltd.