The exceptional abandonment of metal tools by North American hunter-gatherers, 3000 B.P.

Most prehistoric societies that experimented with copper as a tool raw material eventually abandoned stone as their primary medium for tool making. However, after thousands of years of experimentation with this metal, North American hunter-gatherers abandoned it and returned to the exclusive use of stone. Why? We experimentally confirmed that replica copper tools are inferior to stone ones when each is sourced in the same manner as their archaeological counterparts and subjected to identical tasks. Why, then, did copper consistently lead to more advanced metallurgy in most other areas of the world? We suggest that it was the unusual level of purity in the North American copper sourced by North American groups, and that naturally occurring alloys yielded sufficiently superior tools to encourage entry into the copper-bronze-iron continuum of tool manufacture in other parts of the world

Miniaturization optimized weapon killing power during the social stress of late pre-contact North America (AD 600-1600)

Before Europeans arrived to Eastern North America, prehistoric, indigenous peoples experienced a number of changes that culminated in the development of sedentary, maize agricultural lifeways of varying complexity. Inherent to these lifeways were several triggers of social stress including population nucleation and increase, intergroup conflict (warfare), and increased territoriality. Here, we examine whether this period of social stress co-varied with deadlier weaponry, specifically, the design of the most commonly found prehistoric archery component in late pre-contact North America: triangular stone arrow tips (TSAT). The examination of modern metal or carbon projectiles, arrows, and arrowheads has demonstrated that smaller arrow tips penetrate deeper into a target than do larger ones. We first experimentally confirm that this relationship applies to arrow tips made from stone hafted onto shafts made from wood. We then statistically assess a large sample (n = 742) of late pre-contact TSAT and show that these specimens are extraordinarily small. Thus, by miniaturizing their arrow tips, prehistoric people in Eastern North America optimized their projectile weaponry for maximum penetration and killing power in warfare and hunting. Finally, we verify that these functional advantages were selected across environmental and cultural boundaries. Thus, while we cannot and should not rule out stochastic, production economizing, or non-adaptive cultural processes as an explanation for TSAT, overall our results are consistent with the hypothesis that broad, socially stressful demographic changes in late pre-contact Eastern North America resulted in the miniaturization–and augmented lethality–of stone tools across the region

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Refining the chronology of North America's copper using traditions: A macroscalar approach via Bayesian modeling.

North America's ancient copper use, predicted to originate as early as 9000 cal BP, represents the earliest use of native copper for utilitarian tool production in the world. Although recent work has focused on establishing the first use of copper in the western Great Lakes region, little attention has been paid to determining the age ranges of subsequent copper using groups or to the identification of broader trends in copper use during the Archaic Period (10,000-3000 RCYBP). Here we address this issue by applying Bayesian modeling to a comprehensive suite of 76 radiocarbon dates directly associated with copper use. Our results identified two distinct peaks in copper usage, ca. 5500 cal BP and ca. 3300 cal BP. Age ranges for the three Archaic Period traditions and practices associated with copper use of the western Great Lakes are revised using modern calibration curves. Bayesian revisions of age ranges from sites where copper tools and/or production debris have been found provide insight into the historical relationships between, and cultural interactions among, these early copper using groups. This study provides an updated, refined chronology based on the most recent calibration curve (IntCal20) for the varied cultural contexts of copper use across the western Great Lakes

Le Bouffon : journal parodie : paraissant le dimanche / directeur Lucien d'Hura ; rédacteur en chef Le Guillois

01 septembre 18671867/09/01 (A0,N83)

Description and Thermoluminescence (Tl) Dating of An Alleged Hopewell Mobiliary Clay Human Figurine from Hopeton Earthworks, Ross County, Ohio

During a reorganization of the collections at Kent State University (KSU), a fired-clay human figurine was discovered. Beyond the fact that KSU obtained the specimen from a collector, and the alleged origin was the Ohio Hopewell site of Hopeton Earthworks, information on the specimen\u27s provenience and chain of custody was lacking or ambiguous. To determine whether the artifact was consistent in style and age with Hopewell, we conducted a comparative study, as well as a direct chronometric assessment using thermoluminescence (TL) dating. The comparative study was equivocal: The figurine possessed some attributes consistent with Hopewell, but other features were not consistent or missing. TL dating revealed an age of 4590 ± 270, exceeding the Hopewell period by over 2,000 years. These results suggest two mutually exclusive hypotheses, neither of which is relevant to Hopewell: Either the figurine is one of the earliest examples of ceramic technology in eastern North America or it is a fake, perhaps from the Old World, and the object entered the KSU collections under pretense. More broadly, we suggest that archaeologists take a much more circumspect approach to collector-acquired objects and perform their due diligence in verifying the stories associated with them, even if that means increased use of destructive testing procedures

Map of Scioto River Valley, Ohio.

<p>Location of 1) Morrison Village site, 2) Blain Village Site, and 3) location of clay used for experimental sample production.</p

Instron 4-point bend test.

<p>Apparatus showing shell tempered samples (thin on left, thick on right).</p

Deflection curve comparisons.

<p>Charts showing relationships between tempers: grit, limestone, and burnt shell.</p