Estimation of age-at-death for skeletonised forensic remains is one of the most significant problems in forensic anthropology. The majority of existing morphological and histological techniques are highly inaccurate, and show a bias towards underestimating the age of older individuals. One technique which has been successful in forensic age estimation is amino acid racemization in dentine. However, this method cannot be used on remains where the post-mortem interval is greater than 20 years. An alternative approach is to measure amino acid racemization in dental enamel, which is believed to be more resistant to change post-mortem. The extent of amino acid racemization in the acid soluble fraction of the enamel proteins was determined for modem known age teeth. A strong correlation was observed between the age of the tooth and the extent of racemization. No systematic bias in the direction of age estimation errors was detected. For the majority of teeth analyzed, the presence of dental caries did ...

Title: Biomedical Applications of Accelerator Mass Spectrometry. VOLUME: 4 ISSUE: 2. Author(s):Emily L.-C. Cheah and Hwee-Ling Koh. Affiliation:Department of Pharmacy,National University of Singapore, 18 Science Drive 4, Singapore 117543, Singapore.. Keywords:Accelerator mass spectrometry, Radioisotope, Biomedical, Drug development, Microdosing. Abstract: Accelerator mass spectrometry (AMS) has emerged as an important analytical tool in biomedical and pharmaceutical research. Its sensitivity (up to attomole, 10-18 levels), precision, low sample requirements and the ability to trace a biomarker over a prolonged period of time are valuable attributes. Metabolomic, kinetic, toxicokinetic and dosimetric studies of various chemical molecules, at environmental exposure levels and physiologically relevant doses, using radioisotopes (e.g. 14C, 3H, 26Al and 41Ca) are possible. AMS has contributed significantly to the understanding of DNA-adduct formation in carcinogenesis and is finding new uses in the ...

TY - JOUR. T1 - Amino acid racemization in mono-specific foraminifera from Quaternary deep-sea sediments. AU - Kaufman, Darrell S. AU - Cooper, Katherine. AU - Behl, Richard. AU - Billups, Katharina. AU - Bright, Jordon. AU - Gardner, Karleen. AU - Hearty, Paul. AU - Jakobsson, Martin. AU - Mendes, Isabel. AU - OLeary, Michael. AU - Polyak, Leonid. AU - Rasmussen, Tine. AU - Rosa, Francisca. AU - Schmidt, Matthew. PY - 2013/4. Y1 - 2013/4. N2 - The deep-sea environment is among the most stable on Earth, making it well suited for amino acid geochronology. Foraminifera with calcareous tests are distributed across the World Ocean and are often recovered in sufficient abundance from sediment cores to derive robust mean amino acid D/L values of multiple replicates from each stratigraphic level. The extent of racemization (D/L) can be compared with independent age control, which in most cases is based on correlation with global marine oxygen-isotope stages and radiocarbon ages from the same ...

article{74f068fa-017e-403f-85d8-b7d190975c54, abstract = {,p,Radiocarbon dating is the most commonly used chronological tool in archaeological and environmental sciences dealing with the past 50,000 years, making the radiocarbon calibration curve one of the most important records in paleosciences. For the past 12,560 years, the radiocarbon calibration curve is constrained by high quality tree-ring data. Prior to this, however, its uncertainties increase rapidly due to the absence of suitable tree-ring ,sup,14,/sup,C data. Here, we present new high-resolution ,sup,14,/sup,C measurements from 3 floating tree-ring chronologies from the last deglaciation. By using combined information from the current radiocarbon calibration curve and ice core ,sup,10,/sup,Be records, we are able to absolutely date these chronologies at high confidence. We show that our data imply large ,sup,14,/sup,C-age variations during the Bølling chronozone (Greenland Interstadial 1e) - a period that is currently characterized ...

In the 1950s, atomic bomb testing caused large quantities of synthetic 14C to be released into the atmosphere and enter the bodies of living organisms. Methods for calibrating radiocarbon dates from post-bomb materials have been developed over the past two decades and are becoming more applicable in forensics; however, the application of radiocarbon dating concerning medical cadavers has not been fully explored. To determine if human cadavers are viable research subjects, three samples were collected from two human cadavers from the Sanford School of Medicine with known birth and death dates. The intention was to have a lower incisor and a portion of the humerus epiphyses and diaphysis from each cadaver sent to the Center for Applied Isotope Studies (CAIS) at the University of Georgia for radiocarbon dating; however, only the incisor of a cadaver that was born after 1950 was dated. It was expected that the various embalming solutions used on cadavers have no effect on the radiocarbon dates and that

The invention of pottery introduced fundamental shifts in human subsistence practices and sociosymbolic behaviors. Here, we describe the dating of the early pottery from Xianrendong Cave, Jiangxi Province, China, and the micromorphology of the stratigraphic contexts of the pottery sherds and radiocarbon samples. The radiocarbon ages of the archaeological contexts of the earliest sherds are 20,000 to 19,000 calendar years before the present, 2000 to 3000 years older than other pottery found in East Asia and elsewhere. The occupations in the cave demonstrate that pottery was produced by mobile foragers who hunted and gathered during the Late Glacial Maximum. These vessels may have served as cooking devices. The early date shows that pottery was first made and used 10 millennia or more before the emergence of agriculture ...

Weinelt, Mara (2005): Stable isotope data of benthic foraminifera of ODP Site 162-984B. PANGAEA, https://doi.org/10.1594/PANGAEA.319265

The relation between age and amino-acid epimer ratios (alloisoleucine/isoleucine, A/I) of Holocene land snails was quantitatively evaluated through 14C and amino-acid analysis of 33 samples from fluvial and colluvial sediments and rodent middens in the Northern Negev Desert of Israel. A/I is strongly correlated with 14C ages in fluvial and rodent midden deposits (r = 0.95 and 0.94, respectively), permitting age estimates from A/I ratios with precisions of ±700 and ±660 yr. The correlation is weaker in colluvial deposits (r = 0.74), and age estimates from A/I ratios are correspondingly less precise (±1580 yr). This probably results from delayed burial, which exposes the shells to intense radiation on the desert surface. Because of the generally strong relation between age and A/I, amino-acid epimerization analysis of individual shells can be used to identify mixed-age deposits and to reconstruct species chronologies from mixed-age deposits. ...

The most extensive terrestrial outcrops of glacial and glaciomarine deposits in the Eastern CanadianArctic are exposed in sea cliffs along the Clyde Foreland and Qivitu Peninsula of Baffin Island. Collectively known as the Clyde Foreland Formation (CFF), these stacked deposits record at least seven glacial advances. Despite having been the focus of numerous investigations spanning nearly 50 years, no numerical chronological framework for the age of the deposits has been established. Previous studies relied on biostratigraphy and amino acid racemization (AAR) geochronology and postulated that the oldest units were Late Pliocene to Mid-Pleistocene in age. In this paper, we use a cosmogenic radionuclide isochron approach to determine a minimum age for the burial of a paleosol preserved within the CFF. Abundant palynomorphs in the paleosol are dominated by cool-climate taxa. Combining the paleosol burial age with a compilation of published and new CFF AAR data for marine bivalves Hiatella arctica ...

Introduction Amino acid racemization (AAR) has been applied extensively as a method of relative and quantitative dating by evaluating the degree of postmortem conversion of the chiral forms of amin

Forwarded message ---------- From: Peter Douglas ,peter.douglas at mcgill.ca, Date: Thu, Oct 26, 2017 at 8:29 AM I am looking to recruit an M.Sc. or Ph.D. student in the Earth and Planetary Sciences Department at McGill University for a project focused on using methane radiocarbon measurements to quantify fugitive emissions from oil and gas extraction and/or emissions of methane from old permafrost carbon pools. This position would be partially focused on developing methods at McGill for purifying methane from mixed gas samples, and would involve collaborations with the University of Ottawas Lalonde Accelerator Mass Spectrometry Laboratory, as well as Environment and Climate Change Canada. The project is funded through McGills Trottier Institute for Science and Public Policy, and there will be opportunities to engage with the interface between biogeochemical measurements and greenhouse gas mitigation policy. Experience with stable isotope and/or radiocarbon measurements, especially with gas ...

Cosmogenic 36Cl analysis by accelerator mass spectrometry (AMS) is a valuable environmental and geological sciences research tool. Overcoming the stable nuclide 36S isobar interfering with measurement is challenging, however. Traditionally this has required large accelerators, but following recent technical advances it is now possible with 3C30 MeV ion energies. Consequently 5 MV or even smaller modern bespoke spectrometers are now 36Cl-capable, increasing accessibility and promoting wider and more varied 36Cl use. However, the technical ability to identify 36Cl ions is quite distinct from demonstrated high-performance AMS. Such is the theme of this paper. We present a systematic analysis of the accurate measurement of sample radioisotope relative to the stable chlorine, the normalisation of the measured ratio and correction for remaining 36S interference, all combined with the use of stable-isotope dilution to determine sample Cl concentration to begin with. We conclude by showing that ...

The Phoenix Islands Protected Area, in the central Pacific waters of the Republic of Kiribati, is a model for large marine protected area (MPA) development and maintenance, but baseline records of the protected biodiversity in its largest environment, the deep sea (>200 m), have not yet been determined. In general, the equatorial central Pacific lacks biogeographic perspective on deep-sea benthic communities compared to more well-studied regions of the North and South Pacific Ocean. In 2017, explorations by the NOAA ship Okeanos Explorer and R/V Falkor were among the first to document the diversity and distribution of deep-water benthic megafauna on numerous seamounts, islands, shallow coral reef banks, and atolls in the region. Here, we present baseline deep-sea coral species distribution and community assembly patterns within the Scleractinia, Octocorallia, Antipatharia, and Zoantharia with respect to different seafloor features and abiotic environmental variables across bathyal depths (200-2500 m).

DESCRIPTION (provided by applicant): The National Resource for Accelerator Mass Spectrometry (AMS) was established in 1999 to enable biomedical researchers to accurately quantify very low levels of radioisotopes while exploring fundamental issues in biology. In this renewal, we will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements which our collaborators require. We will develop methods to study biochemical pathways and cellular processes down to the level of the single cell. Finally we will develop and validate methods for the application of AMS in human translational research which is a growing area of demand by collaborators and service users. Throughout the tenure of the grant we will continue to provide a resource to the research community that will include service to investigators familiar with AMS, training of investigators in the technology and dissemination of the Resource. Towards these goals, our specific ...

Critical evaluation, tree-ring calibration, and statistical analysis of 95 radiocarbon dates from neolithic and predynastic sites in Upper Egypt and the De

The department Accelerator Mass Spectrometry (AMS) and Isotope Research conducts interdisciplinary research in a broad application spectrum ranging from nuclear astrophysics to environment and biomedical applications utilizing natural and anthropogenic fingerprints of rare isotropes and trace elements. In addition, the technological advancement of AMS to new isotopes is pursued.

Accelerator mass spectrometry (AMS) is an ultra-sensitive method to monitor and trace the environmental exposure levels of 14C-labeled molecules in vivo. Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Using 14C-labeled nicotine and AMS, we have investigated the inhibitory effect of curcumin, garlic squeeze, grapeseed extract, tea polyphenols, vitamin C and vitamin E, respectively, on nicotine-hemoglobin (Hb) adduction in vivo. The results demonstrated that these dietary constituents induced remarkable decrease of nicotine-Hb adducts. The inhibitory fact may afford an important clue of the chemoprevention of the potential nicotine-induced carcinogenesis. ...

Accelerator mass spectrometry (AMS) is currently the most sensitive method for trace DNA adduct detection. O6-Mehtyldeoxyguanosine (O 6-MedG) is a strongly mutagenic lesion formed by a variety of alkylating agents. For this reason this was the adduct of choice for use in this study, the aim of which was to develop a 14C-postlabelling technique, involving incorporation of radiolabel onto O6-MedG adducts after isolation, thus enabling exploitation of AMS to detect low levels of adducts without the need to administer a 14C-labelled compound. A method was developed and optimised for acetylating O6-MedG, in , 90% yields. This method was then used to acetylate the adduct with 14C-acetic anhydride, but changes required for the safe handling of radiolabelled compound altered the reaction product profile, resulting in the major derivative being 14C-di-acetyl O6-MedG, (38% yield). This pure standard was used to determine detection limits of 1.4 pmoles of adduct using HPLC and liquid scintillation counting ...

The ability of accelerator mass spectrometry (AMS) to measure very small concentrations of the nuclides 10 Be, 14 C, 26 Al, 36 Cl, and 129 I has led to many innovative applications in geologic research. To take advantage of this opportunity in the geosciences, it is important to understand how AMS works, how these nuclides are produced, and how they can be applied to geologic problems. We first discuss the basics of AMS, explaining what gives the method its ability to count small numbers of these nuclides. We review how these nuclides are produced and transported in the atmosphere, hydrosphere, and lithosphere. We then explain the ways that AMS is being used to solve a wide range of problems in geologic research by discussing specific applications in areas such as geomorphology, tectonics, climatology, hydrology, and geochronology.

The National Resource for Accelerator Mass Spectrometry (AMS) was established in 1999 to enable biomedical researchers to accurately quantify very low levels of...

Accelerator mass spectrometry (AMS) is a powerful method for the measurement of very low abundance nuclei (10-9 to 10-16) even in a background of much stronger isobars.

Lilley, J.S., Smithson, M.J., Aitken, T.W., Charlesworth, T.R., Cunningham, R.A., Drumm, P.V., Newton, G.W.A., Day, J.P. and Barker, J. (1990) Accelerator Mass Spectrometry : AMS. In: Connell, K. A. and Warner, D. D., (eds.) Nuclear physics : appendix to the Daresbury Annual Report 1989/90. Warrington, U.K. : SERC Daresbury Laboratory. pp. 147-147. ISSN (print) 0265-1815 ...

At this stage fruits and seeds started to change to become light brown, a visual indicator for the time of maximum seed quality. Specimens are now appreciated as temporally and spatially extensive sources of genotypic, phenotypic, and biogeographic data. This is the oldest demonstrably viable and directly dated seed ever reported, the preserved relict of one of the early crops of lotus cultivated by Buddhists at Pulantien after introduction of the religion into the region prior to 372 A.D. A small portion of the dry pericarp of a second lotus fruit from the same locale has been dated as being 332 +/- 135-yr-old (270 +/- 60 yr BP, radiocarbon age) by accelerator mass spectroscopy at the Lawrence Livermore National Laboratory. The general premise of this idea, which we call the paleosymbiosis hypothesis, is that host plants can access and be colonized by fungal root symbionts that have been inactive for millennia. To control the populations, it is necessary to remove adults and young ...

The discovery of new fossils in Africa, Asia, and Europe, and the recognition of a greater diversity in the middle Pleistocene fossil record, has led to a reconsideration of the species Homo heidelbergensis. This nomen, formulated by Schoetensack in 1908 to describe the Mauer jaw (Germany), was almost forgotten during most of the past century. Numerous fossils have been attributed to it but no consensus has arisen concerning their classification. The holotype anatomical traits are still poorly understood, and numerous fossils with no mandibular remains have been placed in the taxon. Some researchers propose H. heidelbergensis as an Afro-European taxon that is ancestral to both modern humans and Neandertals whereas others think it is a strictly European species that is part of the Neandertal lineage. We focus on the validity of H. heidelbergensis, using the traditional basis of species recognition: anatomical description. We provide a comparative morphological analysis using 47 anatomical traits ...

Episodic, large-volume pulses of volcaniclastic sediment and coseismic subsidence of the coast have influenced the development of a late Holocene delta at southern Puget Sound. Multibeam bathymetry, ground-penetrating radar (GPR) and vibracores were used to investigate the morphologic and stratigraphic evolution of the Nisqually River delta. Two fluvial-deltaic facies are recognized on the basis of GPR data and sedimentary characteristics in cores, which suggest partial emplacement from sediment-rich floods that originated on Mount Rainier. Facies S consists of stacked, sheet-like deposits of andesitic sand up to 4 m thick that are continuous across the entire width of the delta. Flat-lying, highly reflective surfaces separate the sand sheets and comprise important facies boundaries. Beds of massive, pumice- and charcoal-rich sand overlie one of the buried surfaces. Organic-rich material from that surface, beneath the massive sand, yielded a radiocarbon age that is time-correlative with a series of

Twitter Facebook Research results show the eruption occurred in the 16th century BC, consistent with the archaeological record. The effects of the eruption were felt as far away as Egypt and what is now Istanbul in Turkey. Other researchers estimated the date of the eruption to about BC using measurements of radiocarbon, sometimes called carbon , from bits of trees, grains and legumes found just below the layer of volcanic ash. By using radiocarbon measurements from the annual rings of trees that lived at the time of the eruption, the UA-led team dates the eruption to someplace between and , a time period which overlaps with the date range from the archeological evidence.. Work conducted at the UA Accelerator Mass Spectrometry Laboratory contributed substantially to the radiocarbon calibration curve currently in use worldwide. Now radiocarbon testing requires just slivers of wood, so Pearson and her colleagues could test the annual growth rings of trees from back to BC - before, during and after ...

Natural abundance radiocarbon analysis facilitates distinct source apportionment between contemporary biomass/biofuel (14C alive) versus fossil fuel (14C dead) combustion. Here, the first compound-specific radiocarbon analysis (CSRA) of atmospheric polycyclic aromatic hydrocarbons (PAHs) was demonstrated for a set of samples collected in Lycksele, Sweden a small town with frequent episodes of severe atmospheric pollution in the winter. Renewed interest in using residential wood combustion (RWC) means that this type of seasonal pollution is of increasing concern in many areas. Five individual/paired PAH isolates from three pooled fortnight-long filter collections were analyzed by CSRA: phenanthrene, fluoranthene, pyrene, benzo[b+k]fluoranthene and indeno[cd]pyrene plus benzo[ghi]perylene; phenanthrene was the only compound also analyzed in the gas phase. The measured Delta 14C for PAHs spanned from -138.3 per mil to 58.0 per mil. A simple isotopic mass balance model was applied to estimate ...

We aim to test whether a method involving the chemical ninhydrin which selects amino acids, the building blocks of proteins, can: recover sufficient carbon from extremely degraded protein in Australian bones for radiocarbon dating. Radiocarbon methods for dating bone select the protein collagen. Most were developed in northern Europe/America where collagen is well preserved in

Summary: The origins and genetic affinity of the aboriginal inhabitants of the Canary Islands, commonly known as Guanches, are poorly understood. Though radiocarbon dates on archaeological remains such as charcoal, seeds, and domestic animal bones suggest that people have inhabited the islands since the 5th century BCE [1, 2, 3], it remains unclear how many times, and by whom, the islands were first settled [4, 5]. Previously published ancient DNA analyses of uniparental genetic markers have shown that the Guanches carried common North African Y chromosome markers (E-M81, E-M78, and J-M267) and mitochondrial lineages such as U6b, in addition to common Eurasian haplogroups [6, 7, 8]. These results are in agreement with some linguistic, archaeological, and anthropological data indicating an origin from a North African Berber-like population [1, 4, 9]. However, to date there are no published Guanche autosomal genomes to help elucidate and directly test this hypothesis. To resolve this, we generated ...

In the study, 44 teeth from 41 individuals were analyzed using racemization (a chemical process in which one amino acid is converted to its counterpart) analysis of tooth crown dentin or radiocarbon analysis of enamel, and 10 of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well.. Carbon-14, or radiocarbon, is naturally produced by cosmic ray interactions with air and is present at low levels in the atmosphere and food. Although nuclear weapons testing was conducted at only a few locations, excess levels of 14C in the atmosphere rapidly dispersed and equalized around the globe.. Since 1963, as a result of a worldwide test ban treaty, 14C levels in the atmosphere have been decreasing exponentially with a mean half-life of 16 years. Carbon-14 levels have not decreased because of radioactive decay (14C has a half-life of 5,730 years), but rather 14C has moved out of the atmosphere due to mixing with large ...

PLoS ONE 12(1): e0169486. doi:10.1371/journal.pone.0169486. The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). … ⇒. ...

Lithostratigraphy, tephra, geochemistry, biomarkers, hydrogen isotopes, radiocarbon dates, age model, chironomid counts and percentages, pollen counts and percentages, reconstructed summer temperatures for the lacustrine sequence of ancient lake Atteköpsmosse in southern Sweden, 15.5-11.3 ka BP.

New radiocarbon dates from Easter Island indicate that the isolated Polynesian island was first colonized around A.D. 1200, up to 800 years later than had previously been thought.

We find that calibration using the most commonly assumed mutation rate of 1 × 10−8 per generation and a 3-year gray wolf generation time would imply that the Taimyr wolf diverged from the Chinese wolf 10,000-14,000 years ago (Figure 3), which is incompatible with its calibrated direct radiocarbon date of ∼35,000 years BP. Instead, the mutation rate must be substantially slower in order to be compatible with the age of the Taimyr individual, and we find that the Taimyr divergence can be accommodated by a mutation rate of 0.4 × 10−8 per generation (Figure 3). However, it should be noted that this assumes that the Taimyr wolf is directly ancestral to the Chinese gray wolf. If there was structure between the ancestors of the Chinese wolf and the Taimyr wolf, the mutation rate would have to be even slower, and as such a rate of 0.4 × 10−8 per generation is conservative. We emphasize that this mutation rate is for non-CpG sites, since SNPs in CpG dinucleotide context were excluded from the ...

Amplified climate warming in the Arctic may cause thaw-remobilization of its large soil organic carbon (SOC) pool. Here we assess the remobilization and preservation of old SOC by the watershed-integrated radiocarbon signature of molecular SOC markers released from northernmost Scandinavia. The radiocarbon analyses revealed a remarkable fractionation for identical vascular plant markers (~420ppm or ~6000 14C years) upon settling from surface water to the underlying sediments. From this, we infer fluvial export of two SOC pools; a young surface peat component, and an old deep mineral soil component. The young pool exists as an easily degradable humic suspension, while the old pool is matrix protected from degradation and ballasted for preferential settling. The two soil types with highest OC in Arctic permafrost evidently exhibit different susceptibilities to degradation. Hence, a significant part of the thaw- released OC may simply be fluvially relocated to sediments instead of being emitted to ...

BackgroundLens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule) completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its 14C content from the atmospheric carbon dioxide. The 14C content of the lens proteins thus reflects the atmospheric content of 14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the 14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric 14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating.Methodology/Principal FindingsOur results allow us to conclude

The results of the study were presented in Florence at the European Conference on Accelerators in Applied Research and Technology (ECAART) and will be published in the volume Leredità del Padre: le reliquie di San Francesco a Cortona (which will be released in a few weeks by Edizioni Messaggero di SantAntonio). The volume will include the complete results of an interdisciplinary investigation which included both scientific and humanist research and which was promoted by the Tuscany Province Chapter of the Franciscan Order Friars Minor Conventual.. The analyses were conducted with a radiocarbon method, measuring the radiocarbon using Accelerator Mass Spectrometry (AMS). From each tunic, researchers took from 5 to 7 samples of fabric, each of which was smaller than one square centimetre and weighed around 10 milligrams. Multiple samples were taken to avoid doubts or ambiguities (due to, for example, the presence of patches that were added to the tunic at a later time), thus increasing the ...

PubMed journal article Paired RNA Radiocarbon and Sequencing Analyses Indicate the Importance of Autotrophy in a Shallow Alluvial Aquife were found in PRIME PubMed. Download Prime PubMed App to iPhone or iPad.

PROJECT DESCRIPTION:. Corals live in a variety of environments, from shallow tropical seas to the deep cold abyss. This project will help advance knowledge of the evolution and identification of corals in the deep sea. Using home computers/laptops, interns will use command line skills to mine existing data for ribosomal RNA genes and genes under positive selection within corals. This will involve genomic data mining, transcript/gene sequence alignments using bioinformatic programs, and gene annotation (i.e., BLAST) to facilitate target-capture bait design and genomic skimming efforts. This project will incorporate other methods including gene prediction analyses, orthologous sequence identification, SNP analysis, phylogenetic tree building efforts and tests for selection. Results gathered from this project will be used to create a target-enrichment bait set to test for directional selection across depth. In addition, new primers will be designed to identify corals from environmental ...

And weve had some pretty good catchers, too - A.J. Pierzynski, (Tim) Laudner, (Dave) Engle, said Rick Stelmaszek, who coaches Minnesotas catchers. But Joe has to be at the top of the list defensively. Hes an elite at the position, and hes just coming into his own. Strangely, the St. Paul native won the award for a season in which he threw out 36 percent of all potential base stealers (29 caught in 80 attempts), the lowest percentage of his four-year career as a regular, and far below his 53 percent rate of 2007. It was still among the ALs best rates, however - the result, Redmond said, of the work Mauer puts into the position. Everybody knows about his (two) batting titles, but he works just as hard on his fielding, said Redmond, who backed up Gold Glove catchers Charles Johnson and Ivan Rodriguez in Florida. We work a lot on footwork, arm strength, blocking balls, technique. You can see how important he takes it, how much pride he has in defense. And not just the physical part, ...

Minnesota Twins Jim Thome (L) and Joe Mauer celebrate their win over the Chicago White Sox at U.S. Cellular Field in Chicago on August 10, 2010. The Twins won 12-6. UPI/Brian Kersey

The deep sea might be cold and dark, but its not barren. Down here, an incredible diversity of corals shelters young fish like grouper, snapper and rockfish. Sharks, rays and other species live and feed here their whole lives. Brightly colored coral gardens, far beyond the reach of the suns rays, dont just nurture deep-sea life.

Service Centers Northeast National Ion Microprobe Facility (NENIMF) The Northeast National Ion Microprobe Facility (NENIMF) is an outgrowth of the Woods Hole Oceanographic Institution (WHOI) Regional Ion Microprobe Facililty. National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) The Woods Hole Oceanographic Institutions National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS) was…

Scope and Content Note From the Record Group: The collection currently consists primarily of the departments contract proposals and final reports, memos, and ...

adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A ...

Like a dog with a bone. How many times have you heard that saying? Dogs and bones - the two seem to go hand-in-hand, with pet parents giving their canine companions bones for entertainment, to prevent bad breath, to help clean their teeth, and for sheer enjoyment. But are animal bones safe for Fido, or do they cause irreparable damage?. Dental Health. One of the surefire ways to ensure your pet is happy and healthy is to maintain his good dental health. Do you treat Fido with the occasional animal bone in an effort to keep his teeth and gums healthy and clean? Well, you may be doing more damage than good. Its not uncommon for a pooch to suffer from a fractured tooth when chowing down on a bone. Think about it - a bone that is strong enough to hold the weight of a large cow is pretty tough… which means those very persistent chewers can easily break a tooth or two before the bone gives way.. Besides the risk of possible tooth fracturing, arent animal bones good for cleaning a dogs teeth? Not ...

TY - JOUR. T1 - Detection of Adriamycin-DNA adducts by accelerator mass spectrometry at clinically relevant Adriamycin concentrations. AU - Coldwell, Kate E.. AU - Cutts, Suzanne M.. AU - Ognibene, Ted J.. AU - Henderson, Paul. AU - Phillips, Don R.. PY - 2008. Y1 - 2008. N2 - Limited sensitivity of existing assays has prevented investigation of whether Adriamycin-DNA adducts are involved in the anti-tumour potential of Adriamycin. Previous detection has achieved a sensitivity of a few Adriamycin-DNA adducts/104 bp DNA, but has required the use of supra-clinical drug concentrations. This work sought to measure Adriamycin-DNA adducts at sub-micromolar doses using accelerator mass spectrometry (AMS), a technique with origins in geochemistry for radiocarbon dating. We have used conditions previously validated (by less sensitive decay counting) to extract [14C]Adriamycin-DNA adducts from cells and adapted the methodology to AMS detection. Here we show the first direct evidence of Adriamycin-DNA ...

Looking for definition of radiocarbon dating? radiocarbon dating explanation. Define radiocarbon dating by Websters Dictionary, WordNet Lexical Database, Dictionary of Computing, Legal Dictionary, Medical Dictionary, Dream Dictionary.

Novothny, Agnes, Frenchen, Manfred, Horvath, Erzsebet, Bradak, Balazs, Oches, Eric A., McCoy, William D. and Stevens, Thomas (2009) Luminescence and amino acid racemization chronology of the loess-paleosol sequence at Sutto, Hungary. Quaternary International, 128(1-2), pp. 62-76. ISSN (print) 1040-6182 ...

We present evidence that the drowning of the −150 m coral reef around Hawaii was caused by rapid sea-level rise associated with meltwater pulse 1A (MWP-1A) during the last deglaciation. New U/Th and 14C accelerator mass spectrometry dates, combined with reinterpretation of existing radiometric dates, constrain the age of the coral reef to 15.2-14.7 ka (U/Th age), indicating that reef growth persisted for 4.3 k.y. following the end of the Last Glacial Maximum at 19 ka. The drowning age of the reef is roughly synchronous with the onset of MWP-1A between 14.7 and 14.2 ka. Dates from coralline algal material range from 14 to 10 cal ka (calibrated radiocarbon age), 1-4 k.y. younger than the coral ages. A paleoenvironmental reconstruction incorporating all available radiometric dates, high-resolution bathymetry, dive observations, and coralgal paleobathymetry data indicates a dramatic rise in sea level around Hawaii ca. 14.7 ka. Paleowater depths over the reef crest increased rapidly above a ...

The answer to this question took the joint efforts of scientists from several countries working together through the European HERMES project. Although shallow by deep-sea coral standards, the reefs at Mingulay are still too deep to study by diving and too remote for daily visits by a research ship. So how do you build up a picture of life in the Mingulay Reef Complex?. The answer is by using deep-sea landers that sit within the corals for up to a year recording information about their environment. The landers used at Mingulay were built by the Royal Netherlands Institute for Sea Research (NIOZ) who brought their research ship RV Pelagia to Mingulay in 2006 and 2007. The landers were equipped with current meters and optical sensors and set down carefully amongst the coral reefs.. The current meters on the landers gave researchers the first idea of the world experienced by Lophelia in its natural habitat within the Mingulay reefs. Even at depths of over 100 m, the corals still feel the effects of ...

The search for fractionally charged particles (FCP) in Nature is ultimately motivated by the belief that the fundamental constituents of the atomic nucleus are quarks, which have charge in integral units of k of the electronic charge. The reported observation of fractional charge in niobium by a group at Stanford University in 1981 has motivated many new efforts to detect FCP in the past few years. The techniques of accelerator mass spectrometry (AMSh) ave been successfully applied to this problem at several laboratories. The method generally involves the use of electrostatic analysis systems to separate the FCP from integrally charged ions, since the mass of the FCP is not known a priori. A variety of materials have been searched in these experiments and the most sensitive limits are at concentration levels of less than 10^(-18) FCP per atom of host material. ...

Feranec, R.S., Kozlowski, A.L., 2018. Onset Age of Deglaciation Following the Last Glacial Maximum in New York State Based on Radiocarbon Ages of Mammalian Megafauna, in: Kehew, A.E., Curry, B.B. (Eds.), Quaternary Glaciation Of The Great Lakes Region: Process, Landforms, Sediments, And Chronology. Geological Society of America, Boulder, Colorado. doi:10.1130/2017.2530(09 ...

Feranec, R.S., Kozlowski, A.L., 2018. Onset Age of Deglaciation Following the Last Glacial Maximum in New York State Based on Radiocarbon Ages of Mammalian Megafauna, in: Kehew, A.E., Curry, B.B. (Eds.), Quaternary Glaciation Of The Great Lakes Region: Process, Landforms, Sediments, And Chronology. Geological Society of America, Boulder, Colorado. doi:10.1130/2017.2530(09 ...

The southeast Australian passive continental margin is narrow, steep and sediment-deficient, and characterized by relatively low rates of modern sedimentation. Upper slope (|1,200 m) sediments comprise mixtures of calcareous and terrigenous sand and mud. Three of twelve sediment cores recovered from geologically-recent, submarine landslides located offshore New South Wales/Queensland (NSW/QLD) are interpreted to have sampled failure surfaces at depths of between 85 and 220 cm below the present-day seabed. Differences in sediment physical properties are recorded above and below the three slide-plane boundaries. Sediment taken directly above the inferred submarine landslide failure surfaces and presumed to be post-landslide, returned radiocarbon ages of 15.8, 20.7 and 20.1 ka. The last two ages correspond to adjacent slide features, which are inferred to be consistent with their being triggered by a single event such as an earthquake. Slope stability models based on classical soil mechanics and measured

Weve got the lineage of the hobbit, Homo floresiensis (in quotation marks because its human status in not yet clear), perhaps diverging more than two million years ago, evolving in isolation in southeast Asia, and apparently going extinct about 17,000 years ago.. Weve got Homo erectus, most likely originating in Africa, giving rise to lineages which continue in the Far East in China and Java, but which eventually go extinct. In Europe, it perhaps gave rise to the species Homo antecessor, Pioneer Man, known from the site of Atapuerca in Spain. Again, going extinct.. In the western part of the Old World, we get the development of a new species, Homo heidelbergensis, present in Europe, Asia and Africa. We knew heidelbergensis had gone two ways, to modern humans and the Neanderthals. But we now know because of the Denisovans that actually heidelbergensis went three ways-in fact the Denisovans seem to represent an off-shoot of the Neanderthal lineage.. North of the Mediterranean, ...

Mauer, 26, was the best player on a team that won its fifth Central Division title in eight seasons. He won his third AL batting title with a .365 average, setting a major league record for batting average by a catcher, and set career highs in homers (28) and runs batted in (96) despite missing the first month of the season because of a back injury. Besides Mauer and Morneau, other Twins to win the award were Rod Carew (1977), Harmon Killebrew (1969) and Zoilo Versalles (1965). In addition to leading the AL in batting average, he was tops in on-base percentage (.444) and slugging percentage (.587), becoming the first player in the American League since George Brett in 1980 to lead in all three categories. When asked which. ...

West Greenland photography holidays. West Greenland photography holidays explore a truly spectacular destination. Small boat tours take you up close to dramatic walls of blue ice and out to traditional Inuit settlements, while evenings offer the chance to witness the stunning Aurora Borealis.

Paula J. Tim Heaton receives funding from the Leverhulme Trust via a research fellowship on Improving the Measurement of Time via Radiocarbon. Geological and archaeological records offer important insights into what seems to be an increasingly uncertain future. The better we understand what conditions Earth has already experienced, the better we can predict and potentially prevent future threats.. Our research, published today in the journal Radiocarbon , offers a way to do just that, through an updated method of calibrating the radiocarbon timescale. Radiocarbon dating has revolutionised our understanding of the past. It is nearly 80 years since Nobel Prize-winning US chemist Willard Libby first suggested minute amounts of a radioactive form of carbon are created in the upper atmosphere.. Libby correctly argued this newly formed radiocarbon or C rapidly converts to carbon dioxide, is taken up by plants during photosynthesis, and from there travels up through the food chain. When organisms ...

Dennis ORourke (KU - PhD in Anthropology, emphasis in genetics) - Foundation Distinguished Professor of Anthropology at the University of Kansas, Director of the KU ancient DNA Laboratory, Associate Director of the Laboratories of Biological Anthropology, and Professor Emeritus University of Utah. My research focuses on the use of molecular genetic methods to address long-standing questions in prehistory. My students and collaborators have conducted fieldwork and research projects in Mexico, the Caribbean, the US Southwest and California, and the North American arctic. Most recently, my group has focused attention on ancient DNA methods to investigate the colonization and dispersal of the North American arctic, and how this informs us about the earlier initial colonization of the Western Hemisphere. Utilizing genomic analyses of both human and archaeofaunal and archaeobotanical materials, my research interests and efforts increasingly are at the intersection of anthropological genetics, ...

For decades archaeologists have been searching for sites that conclusively prove that a pre-Clovis culture existed in the Americas. Several sites have been discovered and excavated within the Western Hemisphere that could potentially be pre-Clovis, but the data is equivocal and has been highly criticized- leaving no sites to date widely accepted as being pre-Clovis. …

Dive into the research topics of Aluminum nitride as a novel aluminum-26 ion source material for accelerator mass spectrometry. Together they form a unique fingerprint. ...

The eight weeks of the module are designed to lead you through the different topics you need to understand for effective use of animal bones in archaeology. We start by considering what bone is and how it is formed; then move onto how it survives (or doesnt!) and is modified in archaeological contexts - the field of taphonomy. Four weeks are dedicated to exploring how bones and teeth differ between the main archaeologically important groups of vertebrates, from camelids to codfish. Finally, we turn our attention to understanding growth structures and how we can make best use of different hard tissues in bioarchaeology.. ...

A preliminary step to uncovering evolutionary relationships between fossil populations is to describe and understand the extent of morphological variation that exists within the fossil record. My primary research interest lays in reconsidering the genus Homo fossil record morphological diversity in order to provide a reassessment of the debated classification of the genus.. More specifically, I am interested in testing the validity of hominin taxa which are relevant to the understanding of key moments of the evolutionary history of our genus.. For instance, I have been working on the validity and definition of Homo heidelbergensis Schoetensack, 1908 a key palaeoanthropological species to the understanding of the common origin of Neandertals and Modern Humans. The species was invented after the discovery of the Mauer mandible (Heidelberg, Germany) and has been used to refer to a possible last common ancestor to both species. I used comparative morphology along with phenetic approaches (numerical ...

Arctic air temperatures have increased in recent decades, along with documented reductions in sea ice, glacier size, and snow cover. However, the extent to which recent Arctic warming has been anomalous with respect to long-term natural climate variability remains uncertain. Here we use 145 radiocarbon dates on rooted tundra plants revealed by receding cold-based ice caps in the eastern Canadian Arctic to show that 5000 years of regional summertime cooling has been reversed, with average summer temperatures of the last ~100 years now higher than during any century in more than 44,000 years, including the peak warmth of the early Holocene when high-latitude summer insolation was 9% greater than present. Reconstructed changes in snowline elevation suggest that summers cooled ~2.7 °C over the past 5,000 years, approximately twice the response predicted by Coupled Model Intercomparison Project Phase 5 climate models. Our results indicate that anthropogenic increases in greenhouse gases have led to ...

West Africa, where the oldest known fossil, from the Iwo Eleru rock shelter in Nigeria, is thought to be less than 15,000 years old. This poorly preserved skeleton was excavated from basal sediments at Iwo Eleru in 1965 by archaeologist Thurstan Shaw and his team, and was associated with Later Stone Age tools. That latter fact alone would suggest a relatively young age, and a radiocarbon date on a piece of charcoal suggested an age of about 13,000 years. The skeleton, and particularly the skull and jaw, was studied in 1971 by Don Brothwell, my predecessor at the Natural History Museum, and he argued that while the specimen could be related to recent populations in West Africa, it actually looked rather different from them. I studied the skull for my Ph.D., with surprising results. I also found that it did not closely resemble recent African populations, but in its long and low shape it was actually closer to early moderns such as those from Skhul, and even to more primitive specimens such as Omo ...

Theres some things that really pop out that Im still scratching my head over, said Widga. For instance, the Missouri animal. Weve got radiocarbon dates on it, and its 13,200 years old. It shares a site with about 35 other mastodons. And we all expected it to plot very closely with everything else from the Midwest, but it bumps out, and it plots with this animal from Alberta. So theres a lot of variability, and we still arent really sure what that means yet.. The authors suggest that figuring out how these ancient animals responded to drastic climate change might help us better understand possible reactions by living animals to the global warming experienced today. One of the things they caution is that, while species might move north and thrive in response to climate change, this might also mean important loss of genetic diversity within those populations. How could that loss impact species ability to cope with potential future challenges?. There is so much more to learn.. This is ...

Some of the El Palenques population moved to Cerro Tilcajete, which is located on the top of a ridge, some 300 m above the level of the valley floor. In 1994, Charles Spencer and Elsa Redmond mapped and surface collected Cerro Tilcajete. The material from the surface collections indicates that the site was occupied during Monte Albán II (100 BC - 200 AD) and Monte Albán IIIB-IV (AD 500-1000). Between 1999-2003, Christina Elson directed the excavation of a palace, a two-room temple, and an elite residence, all situated around Cerro Tilcajetes small Period II plaza. In addition, a low-status house located on a terrace 260 m away from the plaza was excavated. A radiocarbon date from the platform sustaining the palace was 130 AD + 60. Based on this date and on the associated ceramic material, it can be said with confidence site was first occupied in the Monte Albán II Period when it functioned as a secondary center for the Ocotlán-Zimatlán region.. ...

The discovery of Chauvet cave, at Vallon-Pont-dArc (Ardèche), in 1994, was an important event for our knowledge of palaeolithic parietal art as a whole. Its painted and engraved figures, thanks to their number (425 graphic units), and their excellent state of preservation, provide a documentary thesaurus comparable to that of the greatest sites known, and far beyond what had already been found in the group of Rhône valley caves (Ardèche and Gard). But its study - when one places it in its natural regional, cultural and thematic framework - makes it impossible to see it as an isolated entity of astonishing precocity. This needs to be reconsidered, and the affinities that our research has brought to light are clearly incompatible with the very early age which has been attributed to it. And if one extends this examination to the whole of the Franco-Cantabrian domain, the conclusion is inescapable: although Chauvet cave displays some unique characteristics (like every decorated cave), it belongs ...

These files demonstrate the relation between U-series and amino acid results for Gomez Pit and nearby sites in northeastern North Carolina. See descriptive text for each figure.. ...

LIVERMORE Calif. -- DNA damage formed during carcinogenesis is just o...Paul Henderson of Livermores Biology and Biotechnology Research Progr...Karen Dingley of BBRP will present the use of AMS to detect carcinogen...Other presentations include using AMS to study new potential biomarker...Henderson will present an overview of AMS applications in biological r...,Livermore,research,in,accelerator,mass,spectrometry,highlighted,at,ACS,meeting,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters

This is really a postscript to my previous post, a PS with an admittedly strident take- away message: we MUST get that blood radiocarbon-dated. Its that or having to endure a never-ending stream of pseudo-science, epicentre the Vatican (Papal edict: the Shroud is not falsifiable) and surrounding Universities and Polytechnics. (Actually, according to a Daily…

Ive chosen whales: I could have chosen penguins, or turtles, or horses, or, of course, humans. Yes, a missing link has been found between humans and apes. In fact, several have. There is Sahelanthropus, an ape which lived around the time that humans and chimpanzees diverged. Then there are the Ardipithecus and Australopithecus ape-men. Then comes the arbitrary line where we start calling them humans: The genus Homo includes, among others, Homo habilis, Homo erectus, Homo ergaster, Homo heidelbergensis, Homo neandertalis and Homo sapiens, all of which have several fossil examples.. Its actually not very helpful to talk in terms of transitional forms. All species are transitional. Humans will probably look very different, if we exist, in a million years time, but we dont feel like a transitional form between Homo erectus and future humans. Instead its worth talking about transitional characteristics between older species and more recent ones. Tiktaalik, which appears to be an early ...

Now housed in a renovated furniture factory in Omahas booming North-Downtown neighborhood, Mauer and Powell started MTRL with a desire and a passion for creating new, eco-friendly products for the home that solved common problems.. They found themselves using a lot of bamboo and wanted to take their commitment to problem-solving a step further, so they launched a crowdsourcing campaign to bring bamboo to Omaha and cut materials transport out of the equation.. We were able to try four different species of cold hardy timber bamboo, but the Omaha winter killed them, said Mauer.. While they were running the crowdfunding campaign, they started working with architects and interior designers on different projects from signs and displays to shelves and furniture. That side of the business took off and Mauer and Powell started moving toward more client work.. The product [development] went to the back burner as we started working on custom things, said Mauer. We always had the products churning ...

Joe Mauer was set to start on Tuesday against the Royals, a team hes batting .425 against this season and .355 (in 116 games) in his career.. But the All-Star catcher was hit with back spasms right before batting practice and was scratched from the starting lineup. Ryan Doumit replaced him behind the plate and Josh Willingham moved up into Mauers customary No. 3 spot in the lineup.. He was out here early, taking some throws at second base then got ready to hit, Twins manager Ron Gardenhire said. His back tightened up on him and he had spasms and hes out.. Mauer said he was trying to get loose at the time but couldnt make it to the batting cage.. It just locked up, Mauer said after the game.. Mauer hoped that treatment at the park -- and muscle relaxers -- will help him recover in time to play Wednesday. Hes never had back spasms before, so he doesnt know what to expect.. Im in a lot of pain right now, but its calmed down from earlier today, he said. Its feeling a little bit ...

Beryllium dating is used to estimate the time a rock has been exposed on the surface of the Earth, as well as erosion and sedimentation rates.. Beryllium-10 is another cosmogenic nuclide. Like carbon-14, most of it is formed in the earths upper atmosphere. After formation, beryllium-10 binds to atmospheric dust particles or dissolves in atmospheric water vapor. It is transported to earth surface in rain so consequently it has a much shorter atmospheric residence time than carbon-14. It accumulates on the earths surface and depending upon the sedimentation regime in the local environment, it can be used to date surface accumulation rates, surface erosion rates, or for dating layers within ice cores. Its half-life is 1.39 million years.. Vanishingly small amounts of beryllium-10, carbon-14 and aluminum-26 are also created at the earths surface. The creation occurs within minerals the upper meter of rocks exposed directly to the sky. If rocks are undisturbed for millennia, differences in the ...

Aeromagnetic survey in southern West Greenland: project Aeromag 1999 Thorkild M. Rasmussen and Jeroen A.M. van Gool The acquisition of public airborne geophysical data from Greenland that commenced in

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Article Jökulhlaups and sediment transport in Watson River, Kangerlussuaq, West Greenland. For 3 years, during a 4-year observation period (2007–2010), jökulhlaups were observed from a lake at the northern margin of Russells Glet...

Hydro excavation brings a number of benefits to the industrial excavation world. It is now the most preferred method of digging because of its efficient and accurate results.. ​. The primary benefit of hydro excavation is that it provides for better damage and safety control when compared with mechanical methods. Since it is accurate, it limits accidents and injuries for laborers as well as other people. It also does a better job of digging.. ​. Using hydro excavation avoids damage to underground pipes, lines and cables. This in turn eliminates the high expenses needed for repairs and restoration. Needing to do fewer repairs means less time to get the job done too. Interrupted utilities bring inconveniences and high costs. This process of excavation is able to minimize damages.. ​. All these bring long run benefits as well. With the safety risks and repairs lessened, hydro excavation also reduces insurance and liability costs. As this process provides better results, a companys reputation ...

It [Levallois blade] requires a conceptual leap that allows you to envision the desired tool in the flint core before you even start shaping it, Barkai says.. The Levallois style of blade is far more complicated to manufacture than merely banging a rock into shape and is generally considered to be beyond the cognitive abilities of Homo erectus. It is hoped that the extremely early habitation dates at Jaljulia will be confirmed by the more accurate dating process known as optically stimulated luminescence (calculation of the last time grains of sediment were exposed to light). Confirmation of the dating may well indicate that some form of archaic Homo sapiens or Homo heidelbergensis (ancestral Neanderthals) were present in the Levantine region long before scientists thought.. There is the intriguing possibility that the blades manufactured at Jaljulia were the work of the direct ancestors of modern humans living between the time of the first recognisable Homo sapiens and the divergence from the ...

This new molecular data meshes better with key archaeological dates. Earlier genetic studies have shown that Homo heidelbergensis, a direct ancestor of Neanderthals, split from the branch leading to Homo sapiens much more recently, 270,000 to 435,000 years ago.. A slower molecular clock would force scientists to re-think the later turning points in prehistory, including the migration of humans out of Africa. New calculations put humans leaving Africa 120,000 years ago, which seems to fit the archaeological finds, like the 100,000-year-old human fossils that were discovered in Israel.. The slowed clock puts the common ancestor of humans and organutans at 40 million years ago, more than 20 million years before dates derived from abundant fossil evidence. This could complicate matters.. Its possible that the mutation rate isnt constant, and may have slowed in the past 15 million years, which could account for such discrepancies. Ancestral apes were smaller animals than the current living ones, ...

Définitions de Astronomical chronology, synonymes, antonymes, dérivés de Astronomical chronology, dictionnaire analogique de Astronomical chronology (anglais)

Chronology is archaeologys chief preoccupation and prerequisite. The Earliest Americans Theme Study recognizes three major Paleoindian intervals, a possible pre-Clovis one, and a post-Paleoindian one equivalent to what most archaeologists call the Early Archaic Period. Midwestern Paleoindian chronology rests on radiocarbon (and, secondarily, thermoluminescent) dating, typological cross-dating with well dated assemblages and industries elsewhere, geochronology and seriation. Despite the many sources of evidence and inference, Midwestern Paleoindian chronology is highly imperfect, to say the least. Few doubt that Paleoindian cultures arose more than 11,000 rcbp and endured at least for centuries. But many continue to doubt that Paleoindians were the first people in the New World, instead claiming that they were preceded by ancestral cultures reaching back perhaps millennia. Thus, the antiquity of first human occupation must be distinguished from Paleoindian antiquity.. Pre-Clovis Claims in the ...

Radiocarbon analysis of the carbonaceous aerosol allows an apportionment of fossil and non-fossil sources of airborne particulate matter (PM). A chemical separation of total carbon (TC) into its subfractions organic carbon (OC) and elemental carbon (EC) refines this powerful technique, as OC and EC originate from different sources and undergo different processes in the atmosphere. Although C-14 analysis of TC, EC, and OC has recently gained increasing attention, interlaboratory quality assurance measures have largely been missing, especially for the isolation of EC and OC. In this work, we present results from an intercomparison of 9 laboratories for C-14 analysis of carbonaceous aerosol samples on quartz fiber filters. Two ambient PM samples and 1 reference material (RM 8785) were provided with representative filter blanks. All laboratories performed C-14 determinations of TC and a subset of isolated EC and OC for isotopic measurement. In general, C-14 measurements of TC and OC agreed ...

Data of high-volume PM2.5 and TSP aerosol samples, measured in Abisko, northern Sweden. The data cover 18 months of consecutive sampling. Sampling duration is 12-28 days. Further, radiocarbon and ¹²C/¹³C-isotope analysis of some samples are available, to distinguish sources (fossil vs. biomass) of elemental carbon (i.e. black carbon).

On a Tuesday morning in fall 2013, Mike Collins loaded up his RV and started the 11-hour drive from his home in Austin, Texas, to Santa Fe, New Mexico. Collins was en route to the Paleoamerican Odyssey conference, where he and other researchers would lay out their evidence, gathered from sites throughout North, Central, and South America, as part of the ongoing effort to piece together a picture of how and when humans settled these lands millennia ago. It was the biggest gathering of its kind since 1999.. Collins, a Texas State University archaeologist, had precious cargo with him in the form of more than 70 stone tools that hed found during his 15 years of digging at a site in central Texas, roughly midway between Dallas and San Antonio, called Gault. His collection was scrupulously organized into two groups-one that he believes are more than 13,000 years old and a second that he believes were made more recently. The tools-blades, scrapers, and bifaces (typically crafted carefully on both ...

This study attempts to reconstruct food habits through carbon (C) and nitrogen (N) isotope analysis and C/N analysis of charred residues inside pottery from the Primorye in the Russian Far East (Luzanova Sopka 2, Sergeyevka 1, Boisman 2, and Vetka 2 sites). Dates were obtained that were from the later stages of the Rudnaya culture (6980-6485 BP, 7800-7400 cal BP), proto-Boisman type (6760-6330 BP, 7600-7300 cal BP), Boisman culture (6155-4720 BP, 7100-5400 cal BP), and Vetka culture (6030-5870 BP, 6900-6700 cal BP). There are major differences in the carbon and nitrogen isotope ratios between inland sites (δ13C -26.9 to -30.0‰, δ15N 7.6 to 9.3‰) and coastal sites (δ13C -18.1 to -24.2‰, δ15N 9.5 to 14.9‰). The results show that the diet of inland cultures consisted primarily of freshwater fish and terrestrial animals and plants, whereas that of coastal cultures consisted mainly of marine organisms.. ...

Imagine if you could go out walking and easily pick up something that hasnt been touched for hundreds, or even thousands, of years. Conservation paleobiologist and National Geographic grantee Dr. Joshua Miller does bone surveys on the Arctic National Wildlife Refuge (ANWR) in Alaska to study why critical habitats for caribou and other species have changed over time. Miller says,

Meat cleavers and boning knives from Mercer, Wusthof, and Zwilling are used to separate animal bones from select cuts of meat, and in the case of cleavers, to split tough animal bones like spines and ribs. Everything Kitchens cleavers are available in weights up to 1100 grams (2.4 pounds).

Meat cleavers and boning knives from Mercer, Wusthof, and Zwilling are used to separate animal bones from select cuts of meat, and in the case of cleavers, to split tough animal bones like spines and ribs. Everything Kitchens cleavers are available in weights up to 1100 grams (2.4 pounds).