24 research outputs found

    The La Prele Mammoth Site, Converse County, Wyoming, USA

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    The La Prele Mammoth site is a Clovis archaeolog- ical site in Converse County, Wyoming (U.S.A.) that preserves chipped stone artifacts in spatial as- sociation with the remains of a subadult Columbi- an mammoth (Mammuthus columbi). The site was discovered in 1986 and initially tested by George Frison in 1987, but work ceased there until 2014 due to a disagreement with the landowner. In the intervening years, questions arose as to whether the artifacts and mammoth remains were truly associated, and the site was largely dismissed by American archaeologists. Recent excavations have not only demonstrated that La Prele was the loca- tion of a mammoth kill by Clovis hunters around 12,850 years ago, but it also preserves a campsite in close proximity to the kill. The camp includes multiple hearth-centered activity areas that appear to represent domestic spaces, reflected by the pres- ence of a diversity of stone tool forms, bone nee- dles, a bone bead, a large area of hematite-stained matrix, and the butchered and cooked remains of at least one other large mammal species. The site has the potential to inform us about aspects of the social organization of Clovis bands, particularly with respect to mammoth hunting and butchery.The symposium and the volume "Human-elephant interactions: from past to present" were funded by the Volkswagen Foundation

    p3k14c, a synthetic global database of archaeological radiocarbon dates.

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    Archaeologists increasingly use large radiocarbon databases to model prehistoric human demography (also termed paleo-demography). Numerous independent projects, funded over the past decade, have assembled such databases from multiple regions of the world. These data provide unprecedented potential for comparative research on human population ecology and the evolution of social-ecological systems across the Earth. However, these databases have been developed using different sample selection criteria, which has resulted in interoperability issues for global-scale, comparative paleo-demographic research and integration with paleoclimate and paleoenvironmental data. We present a synthetic, global-scale archaeological radiocarbon database composed of 180,070 radiocarbon dates that have been cleaned according to a standardized sample selection criteria. This database increases the reusability of archaeological radiocarbon data and streamlines quality control assessments for various types of paleo-demographic research. As part of an assessment of data quality, we conduct two analyses of sampling bias in the global database at multiple scales. This database is ideal for paleo-demographic research focused on dates-as-data, bayesian modeling, or summed probability distribution methodologies

    A three gene DNA methylation biomarker accurately classifies early stage prostate cancer

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    Background: We identify and validate accurate diagnostic biomarkers for prostate cancer through a systematic evaluation of DNA methylation alterations. Materials and methods: We assembled three early prostate cancer cohorts (total patients = 699) from which we collected and processed over 1300 prostatectomy tissue samples for DNA extraction. Using real-time methylation-specific PCR, we measured normalized methylation levels at 15 frequently methylated loci. After partitioning sample sets into independent training and validation cohorts, classifiers were developed using logistic regression, analyzed, and validated. Results: In the training dataset, DNA methylation levels at 7 of 15 genomic loci (glutathione S-transferase Pi 1 [GSTP1], CCDC181, hyaluronan, and proteoglycan link protein 3 [HAPLN3], GSTM2, growth arrest-specific 6 [GAS6], RASSF1, and APC) showed large differences between cancer and benign samples. The best binary classifier was the GAS6/GSTP1/HAPLN3 logistic regression model, with an area under these curves of 0.97, which showed a sensitivity of 94%, and a specificity of 93% after external validation. Conclusion: We created and validated a multigene model for the classification of benign and malignant prostate tissue. With false positive and negative rates below 7%, this three-gene biomarker represents a promising basis for more accurate prostate cancer diagnosis

    Beyond market share: Accounting for doctoral program size in recent rates of anthropology faculty job placement.

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    Job placement trends in higher education at US institutions are bleak. Within anthropology and other social science disciplines this problem appears to be particularly pronounced. Recent studies focusing on placement in Anthropology using market share analysis have suggested that specific doctoral programs offer a greater chance of placing their graduates in faculty positions. Here we expand on that work, looking beyond market share to the number of graduates placed in positions relative to the total number of program graduates. Our results suggest that while large programs do indeed command the majority of tenure track placements by market share, much of this may be a product of the high numbers of graduates from these programs. Smaller programs can be proportionally as successful at placing their students in tenure track positions. The majority of PhDs in anthropology should anticipate gaining employment outside of a tenure track position. Training students for positions in private industry, government, and other non-faculty opportunities is essential

    Kinetics of Polynucleotide Phosphorylase: Comparison of Enzymes from Streptomyces and Escherichia coli and Effects of Nucleoside Diphosphatesâ–¿

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    We examined the activity of polynucleotide phosphorylase (PNPase) from Streptomyces coelicolor, Streptomyces antibioticus, and Escherichia coli in phosphorolysis using substrates derived from the rpsO-pnp operon of S. coelicolor. The Streptomyces and E. coli enzymes were both able to digest a substrate with a 3′ single-stranded tail although E. coli PNPase was more effective in digesting this substrate than were the Streptomyces enzymes. The kcat for the E. coli enzyme was ca. twofold higher than that observed with the S. coelicolor enzyme. S. coelicolor PNPase was more effective than its E. coli counterpart in digesting a substrate possessing a 3′ stem-loop structure, and the Km for the E. coli enzyme was ca. twice that of the S. coelicolor enzyme. Electrophoretic mobility shift assays revealed an increased affinity of S. coelicolor PNPase for the substrate possessing a 3′ stem-loop structure compared with the E. coli enzyme. We observed an effect of nucleoside diphosphates on the activity of the S. coelicolor PNPase but not the E. coli enzyme. In the presence of a mixture of 20 μM ADP, CDP, GDP, and UDP, the Km for the phosphorolysis of the substrate with the 3′ stem-loop was some fivefold lower than the value observed in the absence of nucleoside diphosphates. No effect of nucleoside diphosphates on the phosphorolytic activity of E. coli PNPase was observed. To our knowledge, this is the first demonstration of an effect of nucleoside diphosphates, the normal substrates for polymerization by PNPase, on the phosphorolytic activity of that enzyme
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