Use of robust methods to determine quadratic surfaces: application to heritage

3D surveys of archaeological elements and the construction of virtual models enable us to reconstruct historical sites. They provide useful data to select specific building processes.Photogrammetry and Terrestrial Laser Scanning (TLS) are the most common techniques to obtain synthetically heritage models. These techniques provide massive data which can only be managed by replacing them by primitive shapes, thereby obtaining more simple models and the explicit geometry of the element. Statistical and robust methods are used for this substitution, thereby avoiding the common errors due to measuring. Of these methods, the most widely used are the least-median-of-squares (LMedS) and the RANSAC method.Another computation method consists in recursive processes based on evolutive-type algorithms to adjust the model to the data captured.This paper describes two surface computation methodologies to determine the modelling of a column shaft located in temple G of the archaeological park of Selinunte (Sicily).     

The charophyte Lamprothamnium succinctum as an environmental indicator: a Holocene example from Tom Thumbs Lagoon,eastern Australia

The palaeobiota from a middle to late Holocene succession in Tom Thumbs Lagoon, N.S.W., Australia, reflects a range of environmental conditions caused by sea-level changes and active estuarine sedimentation. At the base of the succession (～ ?0.4 m AHD) a thin bed, containing molluscs dated at 6.7 ka B.P. by radiocarbon and amino acid racemisation, and foraminifers is indicative of open estuarine conditions. From +0.35 m AHD towards the top of the sequence the charophyte Lamprothamnium succinctum occurs in subrecent deposits. This species is characterised here by statistical measurements, and new characters are described and illustrated. The charophytes record a drop in sea level and the establishment of a lower salinity artificial wetland. The investigation has also established that decalcification in charophytes can be related to acidification produced by the release of organic acids, aggravated after 1928 by anthropogenic pollution.     

Differentiation of archaeological maize (Zea mays L.) from native wild grasses based on starch grain morphology. Cases from the Central Pampas of Argentina

This paper presents, for the first time, a detailed study, from an archaeological perspective, of the morphological characteristics of the starch grains within the kernels of selected native wild grasses found in the Central Pampas of Argentina. We compared native wild grasses to maize starch grains, which can be distinguished from each other based on their size, shape and other attributes. The majority of the studied grains did not share morphological characteristics with maize starch grains. Considering this, it can be said that, if irregular and polyhedral grains with transverse or radial fissures dominate the starch assemblage, maize identification may be done on the basis of both morphology and size. Additionally, this research contributes to the characterization of the starch grains of the Panicoideae subfamily, which includes maize. Several classes of simple and compound starch grains are described and defined for native species of Pooideae, Chloridoideae, Arundinoideae, and Panicoideae subfamilies. The results obtained may constitute a baseline for the future determination of maize and wild grass use in archaeological contexts belonging to Middle/Late Holocene hunter–gatherers in the Pampas of Argentina and neighboring areas.     

Isotopic values of diet of Blastocerus dichotomus (marsh deer) in Paraná Basin,South America

The marsh deer (Blastocerus dichotomus, Illiger, 1815) is the largest contemporary South American deer, and its habitat includes the floodplains and wetlands of eastern South America. Throughout the Holocene these deer were widely used by indigenous societies, from the southern banks of the Amazon River to the Río de la Plata River, and from the Andean foothills to the Atlantic Ocean. However, despite the enormous ecological and archaeological importance of this ungulate in the region, our knowledge of the isotopic values of their diet is almost nonexistent. This paper is the first systematic approach to the study of the isotopic values of this mammal's diet, using archaeological and present-day samples from interconnected watersheds of the Paraná and Uruguay rivers in east-central Argentina. The results obtained from 24 measurements indicate an average value of ?21.09 ± 1.46‰ in δ¹³C collagen, with a low coefficient of variation (6.92%). The data indicate a marked preference for consumption of plants with a C₃ photosynthetic pathway. Most of the observed variability in the isotopic values corresponds to the period 900–1430 ¹⁴C years BP, a time range during which the values show higher consumption of C₄ plants. This it could be related with a period where temperature and associated humidity increased, synchronous in the area with the Medieval Climate Anomaly.     

‘It is not fair that he is treated as a commoner’: lower-level native lords in the repartimiento of Macha (Charcas) under colonial rule, 1540–1619

This article studies the impact of colonial rule on Andean hierarchies of power, underlining the role of lower-level native leaders who enabled paramount lords to organize labor services, levy tribute, and govern Andean polities. Using the repartimiento of Macha (Charcas) as a case study, this article examines the impact of external colonial authorities' actions against the backdrop of rising internal tensions within Andean polities. Segmented polities such as Macha faced increasing tensions, giving rise to new mediating roles for lesser-ranking native leaders, placing the subordinate lords' fight for status at the center of debate. This article starts by exploring the first interrelations between lesser-ranking lords and colonial authorities under the encomienda system through the late 1560s. It then turns to the impact of Viceroy don Francisco de Toledo's reforms in the early 1570s, which simplified and standardized native hierarchies of power within each repartimiento while also fragmenting local Andean elites between tribute-paying lords and those exempted of from it. Finally, the article examines the reactions of lower-level native leaders in the face of new constraints regarding tribute exemption and related obligations in the early seventeenth century, as exemplified by indio principal don Diego Chambi.     

Young people and intentional informal voting in Australia

Compared to most other advanced democracies, Australia experiences fairly high levels of both intentional and unintentional informal (or invalid) voting. Using survey data obtained predominantly from the Australian Election Study and aggregate-level data derived mainly from the Australian Census, we explore whether young people are more likely to cast intentional informal votes. We also reflect on why they might do so. We find that young people are strongly implicated in the rising intentional informal vote rate. We also find that their motivations are linked to the following factors: the young are less likely to be members of political parties, less interested in electoral politics and tend to value voting less than the average citizen. Young people also report higher than average levels of cynicism about politics and lower levels of satisfaction with Australian democracy.