A non-invasive study of Roman Age mosaic glass tesserae by means of Raman spectroscopy

Ancient mosaic tesserae are a range of materials of very varied and complex nature, including pottery, stone and glass. Raman spectroscopy is a powerful tool for the analysis of all these kinds of materials. In the particular case of glasses, this technique can be used both for a study of surface weathering and for the characterization of bulk structure, but it has not yet been extensively used for the characterization of mosaic glass tesserae. We carried out Raman analyses on a set of Roman and Late Antiquity period mosaic glass samples, which allowed a good characterization of both the glass matrix and the crystalline inclusions. All the samples show the typical Raman signatures of soda-lime-silicate glasses. Several crystalline phases were also identified, being relics of raw materials used during the glass manufacturing process, such as quartz and feldspars, or linked to the glass color/opacification, such as bindheimite and cuprite. The analyses also led to the identification in some blue, turquoise and green tesserae of calcium antimonate, whose Raman signature has only recently been recognized in the scientific literature on mosaic glasses. Some emphasis is given to the analysis of red lead-containing tesserae, colored with Cu⁺ ions or even Cu⁰ (or Au⁰) metal nanoparticles. Samples with peculiar compositions, as well as “modern” (and restoration) samples, could quite easily be distinguished from the ancient ones by their Raman spectra.     

Identifying foreigners versus locals in a burial population from Nasca, Peru: an investigation using strontium isotope analysis

During the several thousand years of human occupation in the Nasca drainage on the south coast of Peru, population movement into and out of the region impacted the formation and organization of society, as well as contributed to major cultural transformations. This study identifies foreign versus local individuals through the investigation of burial practices and strontium isotope analysis of human remains from the sites of La Tiza and Pajonal Alto dating from the Early Intermediate Period through the Late Intermediate Period (A.D. 1–1476). Of the ten samples analyzed, two individuals dating to the Middle Horizon were identified as foreigners. One of these individuals was buried in a new elite tomb type providing additional evidence that the Wari state incorporated Nasca into its realm. Two headless individuals, one dating to Middle Nasca with clear evidence of decapitation, and another dating to the Late Intermediate Period who was likely decapitated, were both locals. This suggests the practice of decapitation took place among local groups, and that the practice of decapitation and the use of heads as ritual items or trophies may have continued later in time than previously thought.     

Comparative Seismic Risk Assessment of Basilica-type Churches

ABSTRACT

This paper discusses the seismic risk assessment of a Basilica-type church according to the provisions of the Italian Guidelines. A comparison between the results obtained with local and global approaches is reported, based on a knowledge process aimed to characterize the geometric and mechanical parameters required for a reliable structural analysis. To perform the global analyses the finite element technique was employed, with proper assumptions to account for the nonlinear behavior of masonry. Illustrating a case study, the paper critically discusses about the employability of pushover analysis methods for the seismic assessment of basilica-type churches.     

Regulation,integration and sustainability in the cultural sector

The paper examines the hypothesis of vertical integration between heritage and the performed arts. This is often a response to scarcity, and in many cases it implies conversion of heritage back to its original function. Various issues arise, due to the dilemma given by the potential cost for future generations of a more intensive present exploitation. On the other hand, many benefits are likely to be generated on cultural, economic and financial grounds. Furthermore, the decision‐making processes become quite complex, and adequate changes in regulation are necessary in order to make such a vertical integration consistent with culturally sustainable growth.     

Rock art survey in the ancient oasis of Salūt (northern Sultanate of Oman): a variegated iconographic record

The systematic survey of petroglyphs in the area of the ancient oasis of Salūt, in central Oman, highlighted a rich repertoire of representations that are here discussed against the background of Arabian rock art in general. The region displays an extremely rich number of engravings along the slopes of the Jabal Hammah, north of the main site of Salūt. The majority of the petroglyphs find abundant fitting comparisons in the region. The notable exception of the motif of the “man with halberd” is presented, as it appears to be significantly rare and underlines interpretative issues concerning the so-called T-shaped signs, ubiquitous in Arabian rock art. One of its occurrences was radiocarbon dated to before the mid-first millennium BCE. This and other, relative hints for reconstructing the chronological context of the petroglyphs are discussed, indicating that engravings can be broadly dated from the second millennium BCE onwards.     

Commuter lives: a review symposium on David Bissell's Transit Life

This article presents a series of commentaries on Transit Life: How Commuting is Transforming Our Cities, published by MIT Press in 2018. Centring on an in—depth case study of Sydney, the book argues the need to attend carefully to the fine—grained detail of the commuting experience. In all sorts of ways, Transit Life presents a way of thinking about urban transportation radically different from that used by mainstream transport planners and geographers. Geographical Research asked six researchers—Tim Edensor, Michele Lobo, Debbie Hopkins, Helen Fitt, Juliana Mansvelt, and Donald McNeill—to reflect on what kind of research vistas might be opened up bring the tools of cultural geography and mobility research to the world of commuting. Here are their responses, rounded out by a reply by David Bissell, Transit Life's author.     

Ideological Warriors and Constituent Servants: Understanding the Determinants of Participation on Health Care Legislation in the Polarized Senate

Recent scholarship on the Senate indicates that partisanship and polarization have fundamentally changed the dynamics and the nature of policy making in the institution. To understand how senators balance their roles as constituent servants and partisan warriors, we examine senators’ participation in floor amending on major health legislation over a 10-year period (2000–2010). Health care is central to the ideological divide over the nature of the welfare state and has a significant impact on constituents. Unlike previous studies, we develop a fuller picture of the factors that motivate senators to participate by analyzing both amendments filed to a bill and amendments considered on the floor. We find that minority party status and ideology, both the liberal-conservative dimension and ideological extremism, are important indicators of participation. Furthermore, senators elevate ideology in comparison to constituent need when an issue is a presidential priority. Finally, the influence of constituency factors varies by party. For Democrats, their ideological commitment to the social welfare state makes them more likely to participate on health issues regardless of constituent need. However, Republican senators become more likely to sponsor amendments as the level of observable constituent factors increases.