Effect of mollusc eating on human bone strontium levels

Empirical aspects of the movement of strontium through the food chain suggest that the level of bone strontium can be used as an indicator of the percentage of meat in human diet. In general, skeletal remains from agricultural peoples are expected to have high bone strontium levels relative to hunter-gatherers from the same geographical region because plants contain relatively higher amounts of strontium when compared with animal products. The results of the study described in this paper, however, indicate that the inclusion of molluscs as a component of the diet may produce the opposite of the expected strontium values. Burials from an Archaic (c. 2500 BC) hunting-gathering population excavated from Lu^o25, an archaeological site in northern Alabama, USA, exhibit a mean bone strontium level ( atomic absorption; neutron activation) that is higher than the mean level from an agricultural Mississippian (c. AD 1400) population ( atomic absorption; neutron activation) that was buried at the same site. The samples were analysed by two techniques (atomic absorption spectrometry and neutron activation analysis) and the results compared favourably; therefore, the results can be accepted as valid rather than being due to technique error. We propose that the ingestion of molluscs, whose meat is known to contain large amounts of strontium, has produced this reversal from expected results.     

Multi-element analysis for dietary reconstruction at a balearic Iron Age site

The number of studies using trace elements as indicators of diet has increased with time, but the majority have used few elements and a small sample. The present study has as a principal objective a multi-element analysis of diet in a large sample in which diagenetic changes have been shown to be unimportant. The analysis was made using concentrations of seven elements—Sr, Ba, Mg, Cu, Zn, V and Ca—in 197 individuals from the necropolis of ‘S' Illot des Porros’ (Majorca, Spain). The results show that these individuals would have had a mixed diet with a high meat component, principally of marine origin (molluscs and fish), but with an important consumption of seeds and cereals and a low proportion of vegetables.     

Induced metal-ion exchange in excavated human bone

Excavated human bone was exposed to aqueous solutions containing high concentrations of a single added metal ion in order to examine the extent of introduction of contaminating materials during burial. Variables included pH, temperature, ion concentration, state of bone (whole or crushed), structure of buffer, and counterion. Calcium and sodium showed little increase, and even a decrease in some cases. Strontium, zinc, lead, and magnesium showed large increases probably through heteroionic replacement of calcium. Manganese, aluminum, and potassium showed increases, particularly under neutral conditions, probably through infiltration into voids and defects.     

Capillary Active Interior Insulation Systems for Wall Retrofitting: A More Nuanced Story

To thermally upgrade exterior masonry walls, interior insulation is often the only possible retrofitting technique, especially when dealing with historic buildings. Unfortunately, it is also the riskiest post-insulation technique, as frost damage, interstitial condensation, and other damage patterns might be induced. To diminish those risks, nowadays so-called capillary active interior insulation systems are often promoted. These systems aim a minimal reduction of the inward drying potential, while interstitial condensation is buffered.

Currently, several capillary active systems are on sale. These different types have, however, widely varying properties. In this article, a closer look at the hygrothermal properties and the working principle of a number of “capillary active” interior insulation systems is made. The spread in capillary absorption coefficients and the vapor diffusion resistances of the different systems is discussed and their influence is illustrated. Based on all this, a more nuanced view on capillary active insulation systems is pursued.

Abbreviations: AC: aerated concrete; CaSi: calcium silicate; GM: glue mortar; GB: gypsum board; HAMFEM: Heat Air and Moisture Finite Element Method; MW: mineral wool; PE: polyethylene; PIR: polyisocyanurate; PUR: polyurethane; VIP: vacuum insulation panel; WFB: wood fiber board; XPS: extruded polystyrene; sd_dry: dry vapor diffusion resistance factor; µ_dry: dry vapor diffusion resistance     

丝绸的老化及保护剂的筛选

讨论了光和热对丝绸老化的影响。结果表明,光比热对丝绸之染料的影响大得多;随着辐照时间的增加,丝纤维强度降低曲线呈典型的动力学反应特征。通过抗张强度、白度等测试,对保护剂进行了筛选。     

WHY PHOTOGRAPHY MATTERS TO THE THEORY OF HISTORY

Georges Didi-Huberman's study is concerned with epistemological and ethical questions that arise from visual representations of the Shoah, while Michael Fried's is concerned with the ontological possibilities explored by contemporary art photography. The books have two things in common: an argument against postmodern skepticism, and an insistence that photography has become a field in which questions of history, truth, and authenticity are being explored with particular acuity. Rather than reject even the possibility that photographs have something to tell us about the Shoah, Didi-Huberman shows that they can offer important insights into the difficulties and the possibilities of apprehending some aspects of the past.
Fried shows that contemporary photographic work has taken on the ambitions of high modernism by accepting the challenge of "to-be-seenness." Photography as a "historical practice" does not escape from the difficulties of evidence and of the "constructed" nature of historical understanding; photography functions neither as a pure trace of the past, nor as a mere invitation to spectacle.     

The application of Mössbauer spectroscopy to the characterisation of western mediterranean obsidian

Iron-57 Mössbauer absorption spectra have been measured for samples of obsidian from known geological flows and from archaeological site material from the western Mediterranean region. Of the four main sources available to prehistoric man it is possible to distinguish Sardinian (SA) and Pantellerian obsidian from Lipari obsidian on the basis of differences in the local atomic surroundings of iron atoms, as determined from the Mössbauer spectra. There is, however, some overlap between Lipari and Pontine Island obsidians. The Gabellotto flow on Lipari is readily identified through the presence of magnetite inclusions. The ratio of ferric to ferrous ions is found to be much higher in the surface layers (< 60 μm) than in the bulk obsidian as detected using Mössbauer backscattering.     

Soluble Salts Amplify the Effect of Small Heterogeneities in the Structure of Porous Building Materials During Drying

Salt crystallization is a major cause of degradation in old buildings. One of the issues that stills need clarification is regarding the influence of the salts on the capillary absorption and subsequent drying of porous building materials. This article presents an experimental study that included capillary absorption and evaporative drying tests on two types of material (lime mortar and ceramic brick) using pure water or saturated solutions of six salts (sodium chloride, sodium sulfate, sodium nitrate, sodium carbonate, potassium nitrate, or potassium carbonate). The results of capillary absorption agree only roughly with the linear relationship, predicted by theory, between sorptivity and the square root of the ratio between viscosity η and surface tension σ of the solution (σ/η)^1/2. This poor agreement is probably due to material heterogeneity. The drying dynamics was regular and showed little dispersion between specimens, but only for the uncontaminated materials. Indeed, the drying dynamics of the salt contaminated materials was often irregular or diverged among similar specimens, and the same happened with their salt decay patterns. The main conclusion is that soluble salts can amplify the effects on drying of the small structural heterogeneities that porous building materials normally depict.     

The kibbutz and the ma’abara (transit camp): The case of the Upper Galilee kibbutzim and Kiryat Shmona, 1949–1953

This article examines the relations between the kibbutzim of the Upper Galilee and the Khalsa (Kiryat Shmona) transit camp in its early years. This test case represents a microcosm of the encounter between veteran pioneers and new immigrants, between Ashkenazim and Mizrahim, between those who regarded themselves as the avant-garde of the Labor Zionist movement and new immigrants whose fate symbolized the mass aliyah. The kibbutzim played a decisive role in the establishment of Kiryat Shmona. Their sense of responsibility, compassion, and their genuine desire to help develop social and communal services were no less powerful than their trend towards isolation. However, the kibbutz members’ orientalist views undermined their ability to attain their objectives. Faced with what they perceived as the paternalistic approach of the kibbutzim, the inhabitants of the transit camp, especially the Yemenite immigrants, refused to submit to the powerful pressure exerted upon them to abandon their traditional Jewish culture and manifested their loyalty to their own values.     

陕西、河南地区出土唐代釉陶器釉层剥离原因分析

釉陶器在埋藏过程中,受物理及化学等因素的影响,会产生各种病害,釉层剥离是常见的病害之一。为了更深入地了解唐代釉陶器釉层剥离的原因并为以后的保护提供科学依据,对陕西、河南地区四个遗址出土的唐代釉陶器样品进行了显微观察、成分检测、热膨胀系数分析和吸水率测试。结果显示,四个遗址中,釉面保存相对完整且剥离现象较少的是巩县黄冶窑,而铜川黄堡窑、西安醴泉坊窑和乾县懿德太子墓釉陶器釉层剥离较为严重。进一步研究表明,釉陶器胎釉热膨胀系数不匹配和胎体烧结程度过低(因此造成吸水率过高)是影响釉陶器釉层剥离的主要内在因素。研究结果可为釉陶器的后续保护工作奠定基础。