IRSL and post-IR IRSL residual doses recorded in modern dust samples from the Chinese Loess Plateau

Using a set of modern/young (0 to about 200 years old) dust samples collected from the Chinese Loess Plateau the bleachability of IRSL measured at 50°C (IR₅₀) and post-IR₅₀ elevated temperature IRSL (measured at 225°C and at 290°C) is investigated by measuring the apparent (residual) doses recorded by these signals. Doses recorded by quartz OSL are used as a reference. Allowing for differences in dose rates it seems that both IRSL and post-IR IRSL signals yield residual doses that are significantly larger than the doses measured in quartz. These residual doses can be largely explained by thermal transfer caused by preheating. Nevertheless, we advise against the use of a low temperature preheat (<200°C) with IR₅₀ to date loess samples because, as has been reported before, the signal appears to be thermally unstable. In general, we conclude that it may not be advisable to apply post-IR IRSL dating to Chinese loess samples where residuals of up to ∼20 Gy are a significant fraction of the total dose. However, these residuals quickly become unimportant when dating older samples, and this is the age range in which post-IR IRSL dating is likely to be most useful.     

Village restoration in the Czech Republic

Abstract

The recent political changes in the Czech Republic have led to a major re‐evaluation of the role of the countryside. An extensive Village Restoration Programme is now underway, which is here described, with a detailed example from south Moravia. The holistic nature of the programme is notable.     

Folgen der Emigration deutscher und österreichischer Wissenschaftstheoretiker und Logiker zwischen 1933 und 1945

The paper begins by delimiting the scope of ‘logic’ and ‘philosophy of science’ and goes on to present the biographies and select bibliographies of 36 émigré scholars from Germany and Austria working in these fields. An evaluation of this material, and of data on societies, congresses, lecture series, books and periodicals on logic and philosophy of science, is then undertaken. Against the rich background of activity in the 20s and 30s of our century, there is manifest a rapid decline of high-ranking research in the philosophy of science and (to a lesser degree) in logic in Germany and Austria. Since, with one exception, émigré logicians and philosophers of science did not return after the breakdown of the Third Reich, recovery in these fields has been extremely slow. Pertinent knowledge had to be re-imported, and a satisfactory level has been reached only with the coming of a new generation.     

A parasitological paradox: Why is ascarid infection so rare in the prehistoric Americas?

Ascaris lumbricoides (giant roundworm) and Trichuris trichiura (whipworm) are the most common intestinal parasites found in humans worldwide today and they almost always co-occur. However, we find two distinct patterns in archaeological material. In historical North American and Old World contexts, the association of A. lumbricoides and T. trichiura is similar to the modern epidemiological picture. In contrast, the co-occurrence of A. lumbricoides and T. trichiura eggs in prehistoric South America is rare. For prehistoric contexts, T. trichiura is the most common parasite found in archaeological material. Recently molecular biology techniques pointed to a subdiagnosis of roundworm infection in pre-Columbian South American populations. This is contrary to the modern epidemiological picture in which A. lumbricoides infection is predominant. This is a paradox, especially when one considers the number of eggs laid by female daily, 200,000 and 20,000 thousand per day, for A. lumbricoides and T. trichiura respectively. By reviewing the records of these parasites, this paradox is presented and explanations for the paradox are explored. Taphonomy, prehistoric behavior patterns and medicinal plant use seem to be most relevant to the explanation of the paradox. Nematophagous fungi is a less likely factor creating the near absence of A. lumbricoides eggs in the prehistoric New World.     

On the applicability of post-IR IRSL dating to Japanese loess

Recent work on infrared stimulated luminescence (IRSL) dating has focussed on finding and testing signals which show less or negligible fading. IRSL signals measured at elevated temperature following IR stimulation at 50°C (post-IR IRSL) have been shown to be much more stable than the low temperature IRSL signal and seem to have considerable potential for dating. For Early Pleistocene samples of both European and Chinese loess natural post-IR IRSL signals lying in the saturation region of the laboratory dose response curve have been observed; this suggests that there is no significant fading in nature. As a contribution to the further testing of post-IR IRSL dating, we have used 18 samples from two Japanese loess profiles for which quartz OSL and tephra ages up to 600 ka provide age control. After a preheat of 320°C (60 s), the polymineral fine grains (4–11 μm) were bleached with IR at 50°C (200 s) and the IRSL was subsequently measured at 290°C for 200 s. In general, the fading uncorrected post-IR IRSL ages agree with both the quartz OSL and the tephra ages. We conclude that the post-IR IRSL signal from these samples does not fade significantly and allows precise and accurate age determinations on these sediments.     

Entangled temporalities: Ghana's national biometric identity registration project

Biometric identity registration technologies are spreading throughout the world. Developing countries in particular, have recently been seen to construct biometric population registers in partnership with international donor organizations. This article traces the temporal entanglements produced by transnational policy mobilities in the inception and implementation of Ghana's national biometric identity registration project. In 2008, Ghana famously introduced the first biometric banking system in Africa. Yet, the e‐zwich payment system marked only the first step towards the current ‘craze’ for biometric identity registration in the West African country. Among the numerous biometric identity documents circulating in Ghana's national and subnational institutions, the national Ghanacard is the most interesting identity registration project in the country, both in terms of its population‐wide reach and the complex constellation of institutions, actors and ideas competing within the project. With a focus on the temporalities of policymaking, the article examines the project's fundamental future orientation, the temporal context of its production with its specific possibilities of imagining and acting upon certain matters, and the rhythms and schedules of project implementation. By doing so, it draws attention to some of the ways in which competing sets of ideas shape large‐scale investments in technology and infrastructure in Africa.     

Evaluating chloroplast DNA in prehistoric Texas coprolites: medicinal,dietary, or ambient ancient DNA?

Molecular analysis of coprolites from Hinds Cave, Texas recovered chloroplast DNA sequences. The sequences were interpreted as evidence of diet. We analyzed 19 Hinds Cave coprolites to evaluate the potential sources of the chloroplast DNA (cpDNA) and compared our results to previous studies. This review shows that some cpDNA sequences could be from well-known prehistoric plants foods. Some other sequences could have come from ambient plant material in the guts of small animals eaten by humans in antiquity. Using pollen concentration analysis, we identify sources of ambient plant material which could have been inhaled or imbibed. It is even possible that cpDNA sequences are from proplastids within ambient pollen grains themselves. However, three sequence types cannot be explained as resulting from only dietary or ambient sources. We suggest instead that these might be from medicinal or hallucinogenic plants. We compared these three sequences to existing sequences in the GenBank. We found that these sequences are 100% matches for Rhamnus, Fouquieria, and Solanum.     

Exotericism and the Untroubled Race for the Future

Abstract

The simple case against the philosophic practice of exoteric writing is that it takes too long. Especially short of time are those who would contribute to or even attempt to keep up with the advance of what used to be called natural philosophy. The assumption of progress in science has been purchased with the relentless specialization of its practitioners. In theory transparent to inquiry, in practice specialized, science may be not just anti-exoteric but esoteric.     

Identification of animal skin of historical parchments by polymerase chain reaction (PCR)-based methods

This study deals with establishing of a PCR-based strategy with the aim to recognize the animal origin of different historical parchments. This is one of relatively rare studies on the analysis of ancient DNA from parchments. Robustness of the PCR technology is demonstrated by successful identification of the animal species using only a small amount of DNA isolated from 12 parchment samples. Ten PCR-based assays specific for the detection of different animal species (Bos taurus, Ovis aries, Capra hircus, Sus scrofa, Oryctolagus domestica, Cervus elaphus, Capreolus capreolus, Dama dama) and two PCR assays utilizing universal primers were evaluated and optimized with the aim to find a rapid parchment identification method, which would be more reliable than the classical microscopic examination. The optimized PCR methods produced satisfactory results. Out of 12 investigated parchments, 9 items were unambiguously identified, DNA from 2 samples could not be amplified with any of the species-specific PCR assays, and only one parchment produced controversial results. The species-specific PCR results were confirmed by direct sequencing and PCR cloning with consequent sequencing. Our approach, including isolation of parchment DNA by chaotropic solid-phase extraction, optimization of the PCR programs and high-stringency annealing temperatures, demonstrated to be effective, easy and reliable for the analysis of historical parchment DNA. We consider this PCR-based strategy potentially useful also for investigation of other types of animal items conserved in museums, galleries or libraries.