Kinetic effect of carbonic anhydrase enzyme on the carbonation reaction of lime mortar

The effect of carbonic anhydrase enzyme on the precipitation kinetics and phase transformations of calcium carbonate, and on the strength development of lime mortars has been investigated with saturated lime solutions, lime pastes and lime mortars under atmospheric conditions. The results clearly show that carbonic anhydrase catalyzes the reaction between carbon dioxide and aqueous lime, and increases the rate of calcium carbonate crystallization, the yield of the carbonation reaction and mortar strength at early ages. This is most likely a kinetic effect associated with the increased rate of carbonate ions supply to the solution by the enzyme. In addition, this enzyme favors the formation of stable calcite and significantly modifies its morphology by developing new crystal faces. These results suggest a novel approach for accelerating the hardening of lime mortars using carbonic anhydrase enzyme, which may offer a potentially novel approach with significant benefits on the applications of lime mortars in architectural heritage conservation as well as in construction.     

The Baelo Claudia Paradigm: The Exploitation of Marine Resources in Roman Cetariae

The Roman city of Baelo Claudia (Baetica, Hispania) is one of the best known halieutic sites of the Mare Nostrum, dating from between the 2nd century BC and the 5th century AD. Recent archaeological investigations have included the discovery, excavation and interdisciplinary study of two new fish-salting factories (so-called “Conjuntos Industriales” XI and XII), providing valuable new information on the exploitation of marine resources. This paper provides the first synthesis of all of the available archaeological evidence for the first three phases of the fishing-product cycle (marine resources/fishing equipment/processing facilities and food products) at this unique site on the Strait of Gibraltar.     

Unraveling a Neanderthal palimpsest from a zooarcheological and taphonomic perspective

Practically all archeological assemblages are palimpsests. In spite of the high temporal resolution of Abric Romaní site, level O, dated to around 55 ka, is not an exception. This paper focuses on a zooarcheological and taphonomic analysis of this level, paying special attention to spatial and temporal approaches. The main goal is to unravel the palimpsest at the finest possible level by using different methods and techniques, such as archeostratigraphy, anatomical and taxonomical identification, taphonomic analysis, faunal refits and tooth wear analysis. The results obtained are compared to ethnoarcheological data so as to interpret site structure. In addition, activities carried out over different time spans (from individual episodes to long-term behaviors) are detected, and their spatial extent is explored, allowing to do inferences on settlement dynamics. This leads us to discuss the temporal and spatial scales over which Neanderthals carried out different activities within the site, and how they can be studied through the archeological record.     

Dietary patterns in human populations from northwest Patagonia during Holocene: an approach using Binford’s frames of reference and Bayesian isotope mixing models

The goal of this paper is to assess the variation in the proportional contribution of diverse resources to the diet of human populations from northwest Patagonia (Argentina) throughout the Middle-Late Holocene. Particularly, we assessed the variation among three geographic areas and two periods. We first estimated the expected proportions of terrestrial animals and plants and aquatic resources for each area according to the Binford’s frames of references approach. A Bayesian mixing method was then applied to calculate the proportion of plants and animals in the diets from stable isotopes (δ¹³C and δ¹⁵N) of human bone collagen. The isotope values suggest that the composition of diets differed spatially and temporally. Diets of South Mendoza were mainly composed of terrestrial animals (Rhea-Lama and rodents) with a greater incorporation of C₃ plants towards the later Late Holocene; in North Neuquén, Rhea and Lama represent a proportion of 0.84 of the diet consumed; and finally, the sample of Center Neuquén is the only one with high values of Araucaria in the diet. The isotopic values obtained for the three studied areas did not fit to the expectations of Binford’s model, North Neuquén being the area that departs most from the predicted proportions of terrestrial animals and plants and aquatic organisms in the diet. These findings open up new questions about the local conditions that influenced regional variation in the diet of prehistoric hunter-gatherers.     

The Contribution of Transmission Electron Microscopy (TEM) to Understanding Pre‐Columbian Goldwork Technology

This paper highlights the contribution of transmission electron microscopy (TEM) when combined with scanning electron microscopy and energy‐dispersive X‐ray microanalysis (SEM/XEDS) to characterize objects in archaeology. The application of TEM in archaeology is not yet a common tool, but it may provide data that are significant to understanding pre‐Columbian gold metallurgy, specifically the gilding and silvering methods. Two gilded rods were studied using a combination of TEM and SEM/XEDS techniques. The objects were found at the Atacames archaeological site, in the Esmeraldas region, Ecuador, which was occupied between ad 750 and 1526 by the Atacames culture. The microchemical and structural results of the inner and the external gilded part of the artefacts support the hypothesis of a gold diffusion to the surface enhanced by chemical treatment with chloride‐rich solutions, heating and successive annealing processes. The present study reveals that microstructural investigation by TEM provides useful information with which to investigate the techniques used to modify the chemical surface composition of pre‐Columbian artefacts.     

Rethinking the metaphor of light: María Zambrano in dialogue with Jacques Derrida and Hans Blumenberg

ABSTRACT

The notion of metaphor has been broadly discussed during the twentieth century as an essential and necessary part of language and history. This article examines the theoretical dialogue that links the centrality of the metaphor of light in the work of María Zambrano with reflections on this topic by Jacques Derrida and Hans Blumenberg. Through various formulations of this metaphor across different works, Zambrano presents the metaphor linked to poetic reason as not reducible to a mere rhetorical ornament or to a concept. By articulating alternative metaphors to the imperative of clarity as the blinding light of Occidental reason, Zambrano introduces a solid critique to rationalism and introduces the metaphor of the Dawn as a new form of knowledge. This new intonation of the metaphor of light opens up an unexplored direction in Spanish thought not only by thinking the metaphor of light through poetic reason and its critique to the philosophical tradition, but also by assuming the political implications of this metaphor and criticizing its heliopolitical configuration. Indeed, Zambrano states the significance of the metaphor of the sun linked to the sacrificial structure of history, particularly of Spain, and its necessary overcoming as the possibility of a radical democracy.     

A Kingdom of this world: Religion,politics, power,and the Church in Spanish America

Church and State in Bourbon Mexico: The Diocese of Michoacán, 1749–1810. By D. A. BRADING. Cambridge: Cambridge University Press, 1994. Pp. 300.

Ideología y sociedad en Guadalajara (1788–1853). By BRIAN CONNAUGHTON. Mexico: UNAM‐CONACU, 1992.

La venida del reino. Religión, evangelización y cultura en América. Siglos XVI‐XX. Compiled by GABRIELA RAMOS. Cuzco: Centro de Estudios Regionales Andinos “Bartolomé de las Casas”, 1994.

Autobiografía de una monja venerable. By JERONIMA NAVA Y SAAVEDRA (1669–1727). Study and introduction by ANGELA INES ROBLEDO. Bogotá: Centro Editorial Universidad del Valle, 1994. Pp. 187.

El crédito eclesiástico en la Nueva España: Siglo XVIII. By GISELA VON WOBESER. Mexico: Universidad Nacional Autónoma de México, 1994. Pp. 275.