Restoration of paintings on domes with non-developable geometry (Los Santos Juanes Church in Valencia)

The restoration of paintings on elements in cultural heritage buildings (fundamentally, churches) involves two structural problems: capturing the geometry of the construction element and its development. In many cases, the geometries are regular (e.g., cylinders, spheres, elliptical domes). However, there are cases in which the elements cannot be adapted to any known geometry, much less one that can be mathematically developed. The development of surfaces becomes essential for the restoration of paintings over “flat elements” (over which work is performed on the ground) that are subsequently transferred to the real surface (ceilings). The mathematical transformations that allow regular geometries to be developed are widely known (cartographic projections). However, when the geometry is irregular, there is no development. This study presents a new methodology based on differential rectification and its application for the development of oculi in the Los Santos Juanes Church (Valencia), whose geometry is completely irregular both in shape and as a result of construction defects (and damage caused by fire). The present study focuses on the restoration of paintings damaged by fire.     

“We will not perish; we’re going to keep flourishing”: Race,Food Access,and Geographies of Self‐Reliance

Drawing from 18 months of ethnographic fieldwork in Washington, DC, this article outlines geographies of self‐reliance; a theoretical framework for understanding black food geographies that are embedded in histories of self‐reliance as a response to structural inequalities. Using a community garden as a case study, I argue that the garden functions as a site for addressing several manifestations of structural violence: racist and classist depictions of low‐income and working class people, joblessness, gentrification, and youth underdevelopment. Drawing on self‐reliance ideologies as well as collective and personal histories, the residents exhibit a form of agency that demonstrates unwavering hope in the sustainability of their shared community. Through this analysis, I show that self‐reliance functions as a mechanism through which residents navigate spatial inequalities.     

Revision of the damsel-dragonfly family Campterophlebiidae (Odonata) from the Early Jurassic of England reveals a new genus and species

Kelly, R.S. & Nel, A., October 2017. Revision of the damsel-dragonfly family Campterophlebiidae (Odonata) from the Early Jurassic of England reveals a new genus and species. Alcheringa 42, 87–93. ISSN 0311-5518.

Historical fossil insect collections from England were re-examined and the taxa revised. Lateophlebia gen. nov. is erected for Liassophlebia anglicanopsis (Zeuner) in Campterophlebiidae. Petrophlebia anglicana Tillyard is confirmed in this family and Archithemis liassina (Strickland) is transferred to this family. Lastly, Archithemis brodiei (Geinitz), Archithemis Handlirsch, and Architemistidae Tillyard (reduced to this sole species) are transferred to the Heterophlebioidea.

Richard Kelly [richard.kelly@bristol.ac.uk], School of Earth Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK; Department of Natural Sciences, National Museum of Scotland, Chambers Street, Edinburgh, EH1 1JF, UK. André Nel [anel@mnhn.fr], Institut de Systématique, Évolution, Biodiversité, ISYEB—UMR 7205—CNRS, MNHN, UPMC, EPHE, Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie, F-75005, Paris, France.     

Characterization of concrete from Roman buildings for public spectacles in <Emphasis Type="Italic">Emerita Augusta</Emphasis> (Mérida,Spain)

The aim of this work is to characterize the original concrete from Roman buildings for public spectacles, theatre and amphitheatre, from Emerita Augusta, Mérida, Spain. An advanced knowledge of the Roman concrete composition is required for a reliable restoration and preservation of these ancient monuments. The concrete was studied through mineralogical (optical polarized microscopy and X-ray diffraction) and petrophysical (bulk and real density, open porosity to water and Hg, mechanical strength and ultrasonic velocity) analyses. With this work, it is possible to fill the gap that exists in this field and the characterization of the materials used in the Roman concrete from these two buildings, never previously studied, despite the significance of this archaeological ensemble, declared a World Heritage Site by UNESCO in 1993. The results allowed us to determine the composition of the Roman concrete and to infer the provenance of the aggregates used in these monuments.     

Updating Numerical Models of Masonry Arch Bridges by Operational Modal Analysis

This article aims at presenting and discussing the strategies for updating the finite element numerical modeling of stone masonry arch bridges using operational modal analysis. The study comprehended three bridges: two old ones, the St. Lázaro and the Lagoncinha bridges, and a recently constructed bridge in Vila Fria, Portugal. Updating of the bridge models is performed by comparing the numerical and experimental modal parameters. Three-dimensional detailed numerical models are used to perform modal analysis of the bridges. Experimental modal identification of the bridges is based on the measurement of their acceleration responses during normal operation. The assigned material properties are also based on available results obtained from in situ and laboratory tests and on the results of visual inspection and historical research carried out for both old bridges.     

Food for all: An agent-based model to explore the emergence and implications of cooperation for food storage

Abstract

A consistent access to food is paramount for humans at individual and group level. Besides providing the basic nutritional needs, access to food defines social structures and has stimulated innovation in food procurement, processing and storage. We focus on the social aspects of food storage, namely the role of cooperation for the emergence and maintenance of common stocks. Cooperative food stocks are examined here as a type of common-pool resource, where appropriators must cooperate to avoid shortage (i.e. the tragedy of commons). ‘Food for all’ is an agent-based model in which agents face the social dilemma of whether or not to store in a cooperative stock, adapting their strategies through a simple reinforcement learning mechanism. The model provides insights on the evolution of cooperation in terms of storage efficiency and considering the presence of social norms that regulate reciprocity. For cooperative food storage to emerge and be maintained, a significant dependency on the stored food and some degree of external pressure are needed. In fact, cooperative food storage emerges as the best performing strategy when facing environmental stress. Likewise, an intermediate control over reciprocity favours cooperation for food storage, suggesting that concepts of closed reciprocity are precursors to cooperative stocks, while excess control over reciprocity is detrimental for such institution.