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Sample records for ancient dna strontium

  1. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  2. Authenticity in ancient DNA studies

    DEFF Research Database (Denmark)

    Gilbert, M Thomas P; Willerslev, Eske

    2006-01-01

    Ancient DNA studies represent a powerful tool that can be used to obtain genetic insights into the past. However, despite the publication of large numbers of apparently successful ancient DNA studies, a number of problems exist with the field that are often ignored. Therefore, questions exist as ...

  3. Ancient and modern environmental DNA

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Winther; Overballe-Petersen, Søren; Ermini, Luca

    2015-01-01

    DNA obtained from environmental samples such as sediments, ice or water (environmental DNA, eDNA), represents an important source of information on past and present biodiversity. It has revealed an ancient forest in Greenland, extended by several thousand years the survival dates for mainland woo...

  4. Ancient DNA from marine mammals

    DEFF Research Database (Denmark)

    Foote, Andrew David; Hofreiter, Michael; Morin, Philip A

    2012-01-01

    such as bone, tooth, baleen, skin, fur, whiskers and scrimshaw using ancient DNA (aDNA) approaches provide an oppor- tunity for investigating such changes over evolutionary and ecological timescales. Here, we review the application of aDNA techniques to the study of marine mammals. Most of the studies have...... focused on detecting changes in genetic diversity following periods of exploitation and environmental change. To date, these studies have shown that even small sample sizes can provide useful information on historical genetic diversity. Ancient DNA has also been used in investigations of changes...... in distribution and range of marine mammal species; we review these studies and discuss the limitations of such ‘presence only’ studies. Combining aDNA data with stable isotopes can provide further insights into changes in ecology and we review past studies and suggest future potential applications. We also...

  5. Mitogenomic analyses from ancient DNA

    DEFF Research Database (Denmark)

    Paijmans, Johanna L.A.; Gilbert, M Thomas P; Hofreiter, Michael

    2013-01-01

    analyses (whether using modern or ancient DNA) were largely restricted to the analysis of short fragments of the mitochondrial genome. However, due to many technological advances during the past decade, a growing number of studies have explored the power of complete mitochondrial genome sequences...... (mitogenomes). Such studies were initially limited to analyses of extant organisms, but developments in both DNA sequencing technologies and general methodological aspects related to working with degraded DNA have resulted in complete mitogenomes becoming increasingly popular for ancient DNA studies as well....... To date, at least 124 partially or fully assembled mitogenomes from more than 20 species have been obtained, and, given the rapid progress in sequencing technology, this number is likely to dramatically increase in the future. The increased information content offered by analysing full mitogenomes has...

  6. Phylogenetic estimation of timescales using ancient DNA

    DEFF Research Database (Denmark)

    Molak, Martyna; Lorenzen, Eline; Shapiro, Beth;

    2013-01-01

    In recent years, ancient DNA has increasingly been used for estimating molecular timescales, particularly in studies of substitution rates and demographic histories. Molecular clocks can be calibrated using temporal information from ancient DNA sequences. This information comes from the ages...

  7. gargammel: a sequence simulator for ancient DNA.

    Science.gov (United States)

    Renaud, Gabriel; Hanghøj, Kristian; Willerslev, Eske; Orlando, Ludovic

    2016-10-29

    Ancient DNA has emerged as a remarkable tool to infer the history of extinct species and past populations. However, many of its characteristics, such as extensive fragmentation, damage and contamination, can influence downstream analyses. To help investigators measure how these could impact their analyses in silico, we have developed gargammel, a package that simulates ancient DNA fragments given a set of known reference genomes. Our package simulates the entire molecular process from post-mortem DNA fragmentation and DNA damage to experimental sequencing errors, and reproduces most common bias observed in ancient DNA datasets.

  8. Detecting hybridization using ancient DNA.

    Science.gov (United States)

    Schaefer, Nathan K; Shapiro, Beth; Green, Richard E

    2016-06-01

    It is well established that related species hybridize and that this can have varied but significant effects on speciation and environmental adaptation. It should therefore come as no surprise that hybridization is not limited to species that are alive today. In the last several decades, advances in technologies for recovering and sequencing DNA from fossil remains have enabled the assembly of high-coverage genome sequences for a growing diversity of organisms, including many that are extinct. Thanks to the development of new statistical approaches for detecting and quantifying admixture from genomic data, genomes from extinct populations have proven useful both in revealing previously unknown hybridization events and informing the study of hybridization between living organisms. Here, we review some of the key recent statistical innovations for detecting ancient hybridization using genomewide sequence data and discuss how these innovations have revised our understanding of human evolutionary history.

  9. The biochemistry of ancient DNA in bone.

    Science.gov (United States)

    Tuross, N

    1994-06-15

    The amount of DNA in ancient bone was determined by ethidium bromide staining after the removal of the potent Taq inhibitor, fulvic acid. A complete decalcification and a perfusion protocol were used to recover DNA from bone. A variety of purification techniques including molecular sieve, hydroxyapatite binding and 'Magic' preparations yielded DNA that spanned from 3.4 micrograms/g of bone to below detectable limits. Fulvic acid was shown to interfere with the quantification of DNA derived from ancient human skeletal material one hundred to over seven thousand years old. Scanning UV in the 300 to 230 nm range is a simple and sensitive technique for documenting fulvic acid contamination in ancient bone extracts.

  10. Fossil avian eggshell preserves ancient DNA

    DEFF Research Database (Denmark)

    Oskam, Charlotte L; Haile, James Seymour; McLay, Emma

    2010-01-01

    Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful...

  11. Damage and repair of ancient DNA

    DEFF Research Database (Denmark)

    Mitchell, David; Willerslev, Eske; Hansen, Anders

    2005-01-01

    , and extensive degradation. In the course of this review, we will discuss the current aDNA literature describing the importance of aDNA studies as they relate to important biological questions and the difficulties associated with extracting useful information from highly degraded and damaged substrates derived......Under certain conditions small amounts of DNA can survive for long periods of time and can be used as polymerase chain reaction (PCR) substrates for the study of phylogenetic relationships and population genetics of extinct plants and animals, including hominids. Because of extensive DNA...... degradation, these studies are limited to species that lived within the past 10(4)-10(5) years (Late Pleistocene), although DNA sequences from 10(6) years have been reported. Ancient DNA (aDNA) has been used to study phylogenetic relationships of protists, fungi, algae, plants, and higher eukaryotes...

  12. Ancient DNA analysis of dental calculus.

    Science.gov (United States)

    Weyrich, Laura S; Dobney, Keith; Cooper, Alan

    2015-02-01

    Dental calculus (calcified tartar or plaque) is today widespread on modern human teeth around the world. A combination of soft starchy foods, changing acidity of the oral environment, genetic pre-disposition, and the absence of dental hygiene all lead to the build-up of microorganisms and food debris on the tooth crown, which eventually calcifies through a complex process of mineralisation. Millions of oral microbes are trapped and preserved within this mineralised matrix, including pathogens associated with the oral cavity and airways, masticated food debris, and other types of extraneous particles that enter the mouth. As a result, archaeologists and anthropologists are increasingly using ancient human dental calculus to explore broad aspects of past human diet and health. Most recently, high-throughput DNA sequencing of ancient dental calculus has provided valuable insights into the evolution of the oral microbiome and shed new light on the impacts of some of the major biocultural transitions on human health throughout history and prehistory. Here, we provide a brief historical overview of archaeological dental calculus research, and discuss the current approaches to ancient DNA sampling and sequencing. Novel applications of ancient DNA from dental calculus are discussed, highlighting the considerable scope of this new research field for evolutionary biology and modern medicine.

  13. Paleo-Environmental Reconstruction Using Ancient DNA

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Winther

    The aim of this thesis has been to investigate and expand the methodology and applicability for using ancient DNA deposited in lake sediments to detect and determine its genetic sources for paleo-environmental reconstruction. The aim was furthermore to put this tool into an applicable context...... solving other scientifically interesting questions. Still in its childhood, ancient environmental DNA research has a large potential for still developing, improving and discovering its possibilities and limitations in different environments and for identifying various organisms, both in terms...... of the sampling methods and strategies (taphonomic processes), the more fundamental molecular methodologies (e.g. extraction and sequencing) and eventually the bioinformatic processing. In the enclosed studies we have tried to take some principal steps towards improving this, firstly by reviewing previous...

  14. Ancient bacteria show evidence of DNA repair

    DEFF Research Database (Denmark)

    Johnson, Sarah Stewart; Hebsgaard, Martin B; Christensen, Torben R

    2007-01-01

    Recent claims of cultivable ancient bacteria within sealed environments highlight our limited understanding of the mechanisms behind long-term cell survival. It remains unclear how dormancy, a favored explanation for extended cellular persistence, can cope with spontaneous genomic decay over......-term survival of bacteria sealed in frozen conditions for up to one million years. Our results show evidence of bacterial survival in samples up to half a million years in age, making this the oldest independently authenticated DNA to date obtained from viable cells. Additionally, we find strong evidence...... that this long-term survival is closely tied to cellular metabolic activity and DNA repair that over time proves to be superior to dormancy as a mechanism in sustaining bacteria viability....

  15. Mitochondrial DNA analysis of ancient Sampula population in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The archaeological site of Sampula cemetery was located about 14 km to the southwest of the Luo County in Xinjiang Khotan, China, belonging to the ancient Yutian kingdom. 14C analysis showed that this cemetery was used from 217 B.C. to 283 A.D.Ancient DNA was analyzed by 364 bp of the mitochondrial DNA hypervariable region Ⅰ (mtDNA HVR-Ⅰ), and by six restriction fragment length polymorphism (RFLP) sites of mtDNA coding region. We successfully extracted and sequenced intact stretches of maternally inherited mtDNA from 13 out of 16 ancient Sampula samples. The analysis of mtDNA haplogroup distribution showed that the ancient Sampula was a complex population with both European and Asian characteristics. Median joining network of U3 sub-haplogroup and multi-dimensional scaling analysis all showed that the ancient Sampula had maternal relationship with Ossetian and Iranian.

  16. Non-destructive sampling of ancient insect DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Elias, Scott; Gilbert, Tom

    2009-01-01

    BACKGROUND: A major challenge for ancient DNA (aDNA) studies on insect remains is that sampling procedures involve at least partial destruction of the specimens. A recent extraction protocol reveals the possibility of obtaining DNA from past insect remains without causing visual morphological...... of 77-204 base pairs (-bp) in size using species-specific and general insect primers. CONCLUSION/SIGNIFICANCE: The applied non-destructive DNA extraction method shows promising potential on insect museum specimens of historical age as far back as AD 1820, but less so on the ancient permafrost...... damage. We test the applicability of this protocol on historic museum beetle specimens dating back to AD 1820 and on ancient beetle chitin remains from permafrost (permanently frozen soil) dating back more than 47,000 years. Finally, we test the possibility of obtaining ancient insect DNA directly from...

  17. Non-destructive sampling of ancient insect DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Elias, Scott; Gilbert, Tom;

    2009-01-01

    BACKGROUND: A major challenge for ancient DNA (aDNA) studies on insect remains is that sampling procedures involve at least partial destruction of the specimens. A recent extraction protocol reveals the possibility of obtaining DNA from past insect remains without causing visual morphological...... damage. We test the applicability of this protocol on historic museum beetle specimens dating back to AD 1820 and on ancient beetle chitin remains from permafrost (permanently frozen soil) dating back more than 47,000 years. Finally, we test the possibility of obtaining ancient insect DNA directly from...... of 77-204 base pairs (-bp) in size using species-specific and general insect primers. CONCLUSION/SIGNIFICANCE: The applied non-destructive DNA extraction method shows promising potential on insect museum specimens of historical age as far back as AD 1820, but less so on the ancient permafrost...

  18. 2000 Year-old ancient equids: an ancient-DNA lesson from pompeii remains.

    Science.gov (United States)

    Di Bernardo, Giovanni; Del Gaudio, Stefania; Galderisi, Umberto; Cipollaro, Marilena

    2004-11-15

    Ancient DNA extracted from 2000 year-old equine bones was examined in order to amplify mitochondrial and nuclear DNA fragments. A specific equine satellite-type sequence representing 3.7%-11% of the entire equine genome, proved to be a suitable target to address the question of the presence of aDNA in ancient bones. The PCR strategy designed to investigate this specific target also allowed us to calculate the molecular weight of amplifiable DNA fragments. Sequencing of a 370 bp DNA fragment of mitochondrial control region allowed the comparison of ancient DNA sequences with those of modern horses to assess their genetic relationship. The 16S rRNA mitochondrial gene was also examined to unravel the post-mortem base modification feature and to test the status of Pompeian equids taxon on the basis of a Mae III restriction site polymorphism.

  19. Next Generation Sequencing of Ancient DNA: Requirements, Strategies and Perspectives

    Directory of Open Access Journals (Sweden)

    Michael Knapp

    2010-07-01

    Full Text Available The invention of next-generation-sequencing has revolutionized almost all fields of genetics, but few have profited from it as much as the field of ancient DNA research. From its beginnings as an interesting but rather marginal discipline, ancient DNA research is now on its way into the centre of evolutionary biology. In less than a year from its invention next-generation-sequencing had increased the amount of DNA sequence data available from extinct organisms by several orders of magnitude. Ancient DNA  research is now not only adding a temporal aspect to evolutionary studies and allowing for the observation of evolution in real time, it also provides important data to help understand the origins of our own species. Here we review progress that has been made in next-generation-sequencing of ancient DNA over the past five years and evaluate sequencing strategies and future directions.

  20. Ancestry of modern Europeans: contributions of ancient DNA.

    Science.gov (United States)

    Lacan, Marie; Keyser, Christine; Crubézy, Eric; Ludes, Bertrand

    2013-07-01

    Understanding the peopling history of Europe is crucial to comprehend the origins of modern populations. Of course, the analysis of current genetic data offers several explanations about human migration patterns which occurred on this continent, but it fails to explain precisely the impact of each demographic event. In this context, direct access to the DNA of ancient specimens allows the overcoming of recent demographic phenomena, which probably highly modified the constitution of the current European gene pool. In recent years, several DNA studies have been successfully conducted from ancient human remains thanks to the improvement of molecular techniques. They have brought new fundamental information on the peopling of Europe and allowed us to refine our understanding of European prehistory. In this review, we will detail all the ancient DNA studies performed to date on ancient European DNA from the Middle Paleolithic to the beginning of the protohistoric period.

  1. Pitfalls in the analysis of ancient human mtDNA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The retrieval of DNA from ancient human specimens is not always successful owing to DNA deterioration and contamination although it is vital to provide new insights into the genetic structure of ancient people and to reconstruct the past history. Normally, only short DNA fragments can be retrieved from the ancient specimens. How to identify the authenticity of DNA obtained and to uncover the information it contained are difficult. We employed the ancient mtDNAs reported from Central Asia (including Xinjiang, China) as an example to discern potentially extraneous DNA contamination based on the updated mtDNA phylogeny derived from mtDNA control region, coding region, as well as complete sequence information. Our results demonstrated that many mtDNAs reported are more or less problematic. Starting from a reliable mtDNA phylogeney and combining the available modern data into analysis, one can ascertain the authenticity of the ancient DNA, distinguish the potential errors in a data set, and efficiently decipher the meager information it harbored. The reappraisal of the mtDNAs with the age of more than 2000 years from Central Asia gave support to the suggestion of extensively (pre)historical gene admixture in this region.

  2. New insights on single-stranded versus double-stranded DNA library preparation for ancient DNA

    DEFF Research Database (Denmark)

    Wales, Nathan; Carøe, Christian; Sandoval-Velasco, Marcela

    2015-01-01

    An innovative single-stranded DNA (ssDNA) library preparation method has sparked great interest among ancient DNA (aDNA) researchers, especially after reports of endogenous DNA content increases >20-fold in some samples. To investigate the behavior of this method, we generated ss......DNA and conventional double-stranded DNA (dsDNA) libraries from 23 ancient and historic plant and animal specimens. We found ssDNA library preparation substantially increased endogenous content when dsDNA libraries contained...

  3. A blind testing design for authenticating ancient DNA sequences.

    Science.gov (United States)

    Yang, H; Golenberg, E M; Shoshani, J

    1997-04-01

    Reproducibility is a serious concern among researchers of ancient DNA. We designed a blind testing procedure to evaluate laboratory accuracy and authenticity of ancient DNA obtained from closely related extant and extinct species. Soft tissue and bones of fossil and contemporary museum proboscideans were collected and identified based on morphology by one researcher, and other researchers carried out DNA testing on the samples, which were assigned anonymous numbers. DNA extracted using three principal isolation methods served as template in PCR amplifications of a segment of the cytochrome b gene (mitochondrial genome), and the PCR product was directly sequenced and analyzed. The results show that such a blind testing design performed in one laboratory, when coupled with phylogenetic analysis, can nonarbitrarily test the consistency and reliability of ancient DNA results. Such reproducible results obtained from the blind testing can increase confidence in the authenticity of ancient sequences obtained from postmortem specimens and avoid bias in phylogenetic analysis. A blind testing design may be applicable as an alternative to confirm ancient DNA results in one laboratory when independent testing by two laboratories is not available.

  4. Analysis of Mitochondrial DNA from the Ancient Tombs of Turfan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    MtDNA was successfully extracted from ten individual bones (femurs) in the tombs of ancient Jushi in Turfan basin, dated back to the year about 3 000-2 500 years ago. By means of four overlapping primers, we got nucleotide sequence of the 218bp length. Ancient mtDNA was analyzed by the sequencing of hypervariable region Ⅰ of the mtDNA control region. The result shows that 9 haplotypes with 24 polymorphic sites were obtained. The phylogenetic analysis indicated that Mongolians and Altai are the population genetically closest to the Jushi groups and Jushi mtDNA pool being an admixture of eastern Asian and European lineages. So our preliminary data imply that an ancient mingling of Euro-Asian population had existed in Turfan basin prior to the early Iron Age.

  5. Preservation potential of ancient plankton DNA in Pleistocene marine sediments

    NARCIS (Netherlands)

    Boere, A.C.; Rijpstra, W.I.C.; de Lange, G.J.; Sinninghe Damsté, J.S.; Coolen, M.J.L.

    2011-01-01

    Recent studies have shown that ancient plankton DNA can be recovered from Holocene lacustrine and marine sediments, including from species that do not leave diagnostic microscopic fossils in the sediment record. Therefore, the analysis of this so-called fossil plankton DNA is a promising approach fo

  6. Using Ancient DNA to Understand Evolutionary and Ecological Processes

    DEFF Research Database (Denmark)

    Orlando, Ludovic Antoine Alexandre; Cooper, Alan

    2014-01-01

    Ancient DNA provides a unique means to record genetic change through time and directly observe evolutionary and ecological processes. Although mostly based on mitochondrial DNA, the increasing availability of genomic sequences is leading to unprecedented levels of resolution. Temporal studies of ...

  7. Proboscidean DNA from museum and fossil specimens: an assessment of ancient DNA extraction and amplification techniques.

    Science.gov (United States)

    Yang, H; Golenberg, E M; Shoshani, J

    1997-06-01

    Applications of reliable DNA extraction and amplification techniques to postmortem samples are critical to ancient DNA research. Commonly used methods for isolating DNA from ancient material were tested and compared using both soft tissue and bones from fossil and contemporary museum proboscideans. DNAs isolated using three principal methods served as templates in subsequent PCR amplifications, and the PCR products were directly sequenced. Authentication of the ancient origin of obtained nucleotide sequences was established by demonstrating reproducibility under a blind testing system and by phylogenetic analysis. Our results indicate that ancient samples may respond differently to extraction buffers or purification procedures, and no single method was universally successful. A CTAB buffer method, modified from plant DNA extraction protocols, was found to have the highest success rate. Nested PCR was shown to be a reliable approach to amplify ancient DNA templates that failed in primary amplification.

  8. The First Attested Extraction of Ancient DNA in Legumes (Fabaceae).

    Science.gov (United States)

    Mikić, Aleksandar M

    2015-01-01

    Ancient DNA (aDNA) is any DNA extracted from ancient specimens, important for diverse evolutionary researches. The major obstacles in aDNA studies are mutations, contamination and fragmentation. Its studies may be crucial for crop history if integrated with human aDNA research and historical linguistics, both general and relating to agriculture. Legumes (Fabaceae) are one of the richest end economically most important plant families, not only from Neolithic onwards, since they were used as food by Neanderthals and Paleolithic modern man. The idea of extracting and analyzing legume aDNA was considered beneficial for both basic science and applied research, with an emphasis on genetic resources and plant breeding. The first reported successful and attested extraction of the legume aDNA was done from the sample of charred seeds of pea (Pisum sativum) and bitter vetch (Vicia ervilia) from Hissar, southeast Serbia, dated to 1,350-1,000 Before Christ. A modified version of cetyltrimethylammonium bromide (CTAB) method and the commercial kit for DNA extraction QIAGEN DNAesy yielded several ng μl(-1) of aDNA of both species and, after the whole genome amplification and with a fragment of nuclear ribosomal DNA gene 26S rDNA, resulted in the detection of the aDNA among the PCR products. A comparative analysis of four informative chloroplast DNA regions (trnSG, trnK, matK, and rbcL) among the modern wild and cultivated pea taxa demonstrated not only that the extracted aDNA was genuine, on the basis of mutation rate, but also that the ancient Hissar pea was most likely an early domesticated crop, related to the modern wild pea of a neighboring region. It is anticipated that this premier extraction of legume aDNA may provide taxonomists with the answers to diverse questions, such as leaf development in legumes, as well as with novel data on the single steps in domesticating legume crops worldwide.

  9. New insights on single-stranded versus double-stranded DNA library preparation for ancient DNA.

    Science.gov (United States)

    Wales, Nathan; Carøe, Christian; Sandoval-Velasco, Marcela; Gamba, Cristina; Barnett, Ross; Samaniego, José Alfredo; Madrigal, Jazmín Ramos; Orlando, Ludovic; Gilbert, M Thomas P

    2015-12-01

    An innovative single-stranded DNA (ssDNA) library preparation method has sparked great interest among ancient DNA (aDNA) researchers, especially after reports of endogenous DNA content increases >20-fold in some samples. To investigate the behavior of this method, we generated ssDNA and conventional double-stranded DNA (dsDNA) libraries from 23 ancient and historic plant and animal specimens. We found ssDNA library preparation substantially increased endogenous content when dsDNA libraries contained DNA, but this enrichment is less pronounced when dsDNA preparations successfully recover short endogenous DNA fragments (mean size < 70 bp). Our findings can help researchers determine when to utilize the time- and resource-intensive ssDNA library preparation method.

  10. Preservation of ancient DNA in thermally damaged archaeological bone

    Science.gov (United States)

    Ottoni, Claudio; Koon, Hannah E. C.; Collins, Matthew J.; Penkman, Kirsty E. H.; Rickards, Olga; Craig, Oliver E.

    2009-02-01

    Evolutionary biologists are increasingly relying on ancient DNA from archaeological animal bones to study processes such as domestication and population dispersals. As many animal bones found on archaeological sites are likely to have been cooked, the potential for DNA preservation must be carefully considered to maximise the chance of amplification success. Here, we assess the preservation of mitochondrial DNA in a medieval cattle bone assemblage from Coppergate, York, UK. These bones have variable degrees of thermal alterations to bone collagen fibrils, indicative of cooking. Our results show that DNA preservation is not reliant on the presence of intact collagen fibrils. In fact, a greater number of template molecules could be extracted from bones with damaged collagen. We conclude that moderate heating of bone may enhance the retention of DNA fragments. Our results also indicate that ancient DNA preservation is highly variable, even within a relatively recent assemblage from contexts conducive to organic preservation, and that diagenetic parameters based on protein diagenesis are not always useful for predicting ancient DNA survival.

  11. Pathogenic microbial ancient DNA: a problem or an opportunity?

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2006-01-01

    -controlled and rigorous studies that address technical issues and reliability criteria. This is unfortunate, as the rapid evolutionary rate of many pathogens offers a unique means to establish the authenticity of ancient pathogen sequences-since they should clearly be ancestral to modern genetic diversity (e.g. Reid et......) report that direct sequencing of ancient microbial DNA produced a sequence resembling (for example) Treponerma pallidum (the causative agent of venereal syphilis) even in the absence of real T. pallidum, simply due to the presence of diverse bacterial DNA in the experiment. In addition, the limited...... knowledge of current microbial diversity (only 1-5% of extant microbial diversity is believed to be known) makes it very difficult to use short aDNA sequences to establish unequivocally the presence of a given pathogen, as even supposed ‘obligate' species of humans or plants may possess currently undetected...

  12. Ancient DNA: genomic amplification of Roman and medieval bovine bones

    Directory of Open Access Journals (Sweden)

    A. Valentini

    2010-04-01

    Full Text Available Cattle remains (bones and teeth of both roman and medieval age were collected in the archaeological site of Ferento (Viterbo, Italy with the aim of extracting and characterising nucleic acids. Procedures to minimize contamination with modern DNA and to help ancient DNA (aDNA preservation of the archaeological remains were adopted. Different techniques to extract aDNA (like Phenol/chloroform extraction from bovine bones were tested to identify the method that applies to the peculiar characteristics of the study site. Currently, aDNA investigation is mainly based on mtDNA, due to the ease of amplification of the small and high-copied genome and to its usefulness in evolutionary studies. Preliminary amplification of both mitochondrial and nuclear aDNA fragments from samples of Roman and medieval animals were performed and partial specific sequences of mitochondrial D-loop as well as of nuclear genes were obtained. The innovative amplification of nuclear aDNA could enable the analysis of genes involved in specific animal traits, giving insights of ancient economic and cultural uses, as well as providing information on the origin of modern livestock population.

  13. Statistical guidelines for detecting past population shifts using ancient DNA

    DEFF Research Database (Denmark)

    Mourier, Tobias; Ho, Simon; Gilbert, M Thomas P;

    2012-01-01

    results provide useful guidelines for scaling sampling schemes and for optimizing our ability to infer past population dynamics. In addition, our results suggest that many ancient DNA studies may face power issues in detecting moderate demographic collapses and/or highly dynamic demographic shifts when...... quantitative and temporal sampling schemes, we test the power of ancient mitochondrial sequences and nuclear single-nucleotide polymorphisms (SNPs) to detect past population bottlenecks. Within our simulated framework, mitochondrial sequences have only limited power to detect subtle bottlenecks and/or fast...... post-bottleneck recoveries. In contrast, nuclear SNPs can detect bottlenecks followed by rapid recovery, although bottlenecks involving reduction of less than half the population are generally detected with low power unless extensive genetic information from ancient individuals is available. Our...

  14. An ancient protein-DNA interaction underlying metazoan sex determination.

    Science.gov (United States)

    Murphy, Mark W; Lee, John K; Rojo, Sandra; Gearhart, Micah D; Kurahashi, Kayo; Banerjee, Surajit; Loeuille, Guy-André; Bashamboo, Anu; McElreavey, Kenneth; Zarkower, David; Aihara, Hideki; Bardwell, Vivian J

    2015-06-01

    DMRT transcription factors are deeply conserved regulators of metazoan sexual development. They share the DM DNA-binding domain, a unique intertwined double zinc-binding module followed by a C-terminal recognition helix, which binds a pseudopalindromic target DNA. Here we show that DMRT proteins use a unique binding interaction, inserting two adjacent antiparallel recognition helices into a widened DNA major groove to make base-specific contacts. Versatility in how specific base contacts are made allows human DMRT1 to use multiple DNA binding modes (tetramer, trimer and dimer). Chromatin immunoprecipitation with exonuclease treatment (ChIP-exo) indicates that multiple DNA binding modes also are used in vivo. We show that mutations affecting residues crucial for DNA recognition are associated with an intersex phenotype in flies and with male-to-female sex reversal in humans. Our results illuminate an ancient molecular interaction underlying much of metazoan sexual development.

  15. Assessing the fidelity of ancient DNA sequences amplified from nuclear genes

    DEFF Research Database (Denmark)

    Binladen, Jonas; Wiuf, Carsten Henrik; Gilbert, M. Thomas P.

    2006-01-01

    To date, the field of ancient DNA has relied almost exclusively on mitochondrial DNA (mtDNA) sequences. However, a number of recent studies have reported the successful recovery of ancient nuclear DNA (nuDNA) sequences, thereby allowing the characterization of genetic loci directly involved in ph...

  16. The first attested extraction of ancient DNA in legumes (Fabaceae

    Directory of Open Access Journals (Sweden)

    Aleksandar M. Mikić

    2015-11-01

    Full Text Available Ancient DNA (aDNA is any DNA extracted from ancient specimens, important for diverse evolutionary researches. The major obstacles in aDNA studies are mutations, contamination and fragmentation. Its studies may be crucial for crop history if integrated with human aDNA research and historical linguistics, both general and relating to agriculture. Legumes (Fabaceae are one of the richest end economically most important plant families, not only from Neolithic onwards, since they were used as food by Neanderthals and Paleolithic modern man. The idea of extracting and analysing legume aDNA was considered beneficial for both basic science and applied research, with an emphasis on genetic resources and plant breeding. The first reported successful and attested extraction of the legume aDNA was done from the sample of charred seeds of pea (Pisum sativum and bitter vetch (Vicia ervilia from Hissar, southeast Serbia, dated to 1,350 - 1,000 Before Christ. A modified version of cetyltrimethylammonium bromide (CTAB method and the commercial kit for DNA extraction QIAGEN DNAesy yielded several ng μl-1 of aDNA of both species and, after the whole genome amplification and with a fragment of nuclear ribosomal DNA gene 26S rDNA, resulted in the detection of the aDNA among the PCR products. A comparative analysis of four informative chloroplast DNA regions (trnSG, trnK, matK and rbcL among the modern wild and cultivated pea taxa demonstrated not only that the extracted aDNA was genuine, on the basis of mutation rate, but also that the ancient Hissar pea was most likely an early domesticated crop, related to the modern wild pea of a neighbouring region. It is anticipated that this premier extraction of legume aDNA may provide taxonomists with the answers to diverse questions, such as leaf development in legumes, as well as with novel data on the single steps in domesticating legume crops worldwide.

  17. Ancient DNA perspectives on American colonization and population history.

    Science.gov (United States)

    Raff, Jennifer A; Bolnick, Deborah A; Tackney, Justin; O'Rourke, Dennis H

    2011-12-01

    Ancient DNA (aDNA) analyses have proven to be important tools in understanding human population dispersals, settlement patterns, interactions between prehistoric populations, and the development of regional population histories. Here, we review the published results of sixty-three human populations from throughout the Americas and compare the levels of diversity and geographic patterns of variation in the ancient samples with contemporary genetic variation in the Americas in order to investigate the evolution of the Native American gene pool over time. Our analysis of mitochondrial haplogroup frequencies and prehistoric population genetic diversity presents a complex evolutionary picture. Although the broad genetic structure of American prehistoric populations appears to have been established relatively early, we nevertheless identify examples of genetic discontinuity over time in select regions. We discuss the implications this finding may have for our interpretation of the genetic evidence for the initial colonization of the Americas and its subsequent population history.

  18. Highly informative ancient DNA 'snippets' for New Zealand moa.

    Directory of Open Access Journals (Sweden)

    Jonathan McCallum

    Full Text Available BACKGROUND: Analysis of ancient DNA has provided invaluable information on past ecologies, ancient populations, and extinct species. We used a short snippet of highly variable mitochondrial control region sequence from New Zealand's moa to characterise a large number of bones previously intractable to DNA analysis as well as bone fragments from swamps to gain information about the haplotype diversity and phylogeography that existed in five moa species. METHODOLOGY/PRINCIPAL FINDINGS: By targeting such 'snippets', we show that moa populations differed substantially in geographic structure that is likely to be related to population mobility and history. We show that populations of Pachyornis geranoides, Dinornis novaezealandiae, and Dinornis robustus were highly structured and some appear to have occupied the same geographic location for hundreds of thousands of years. In contrast, populations of the moa Anomalopteryx didiformis and Euryapteryx curtus were widespread, with specific populations of the latter occupying both the North and South Islands of New Zealand. We further show that for a specific area, in this case a North Island swamp, complete haplotype diversity and even sex can be recovered from collections of small, often discarded, bone fragments. CONCLUSIONS/SIGNIFICANCE: Short highly variable mitochondrial 'snippets' allow successful typing of environmentally damaged and fragmented skeletal material, and can provide useful information about ancient population diversity and structure without the need to sample valuable, whole bones often held by museums.

  19. Application and comparison of large-scale solution-based DNA capture-enrichment methods on ancient DNA

    DEFF Research Database (Denmark)

    Avila Arcos, Maria del Carmen; Cappellini, Enrico; Romero-Navarro, J Alberto

    2011-01-01

    The development of second-generation sequencing technologies has greatly benefitted the field of ancient DNA (aDNA). Its application can be further exploited by the use of targeted capture-enrichment methods to overcome restrictions posed by low endogenous and contaminating DNA in ancient samples...

  20. No ancient DNA damage in Actinobacteria from the Neanderthal bone.

    Directory of Open Access Journals (Sweden)

    Katarzyna Zaremba-Niedźwiedzka

    Full Text Available BACKGROUND: The Neanderthal genome was recently sequenced using DNA extracted from a 38,000-year-old fossil. At the start of the project, the fraction of mammalian and bacterial DNA in the sample was estimated to be <6% and 9%, respectively. Treatment with restriction enzymes prior to sequencing increased the relative proportion of mammalian DNA to 15%, but the large majority of sequences remain uncharacterized. PRINCIPAL FINDINGS: Our taxonomic profiling of 3.95 Gb of Neanderthal DNA isolated from the Vindija Neanderthal Vi33.16 fossil showed that 90% of about 50,000 rRNA gene sequence reads were of bacterial origin, of which Actinobacteria accounted for more than 75%. Actinobacteria also represented more than 80% of the PCR-amplified 16S rRNA gene sequences from a cave sediment sample taken from the same G layer as the Neanderthal bone. However, phylogenetic analyses did not identify any sediment clones that were closely related to the bone-derived sequences. We analysed the patterns of nucleotide differences in the individual sequence reads compared to the assembled consensus sequences of the rRNA gene sequences. The typical ancient nucleotide substitution pattern with a majority of C to T changes indicative of DNA damage was observed for the Neanderthal rRNA gene sequences, but not for the Streptomyces-like rRNA gene sequences. CONCLUSIONS/SIGNIFICANCE: Our analyses suggest that the Actinobacteria, and especially members of the Streptomycetales, contribute the majority of sequences in the DNA extracted from the Neanderthal fossil Vi33.16. The bacterial DNA showed no signs of damage, and we hypothesize that it was derived from bacteria that have been enriched inside the bone. The bioinformatic approach used here paves the way for future studies of microbial compositions and patterns of DNA damage in bacteria from archaeological bones. Such studies can help identify targeted measures to increase the relative amount of endogenous DNA in the

  1. Comparing Ancient DNA Preservation in Petrous Bone and Tooth Cementum

    Science.gov (United States)

    Margaryan, Ashot; Stenderup, Jesper; Lynnerup, Niels; Willerslev, Eske; Allentoft, Morten E.

    2017-01-01

    Large-scale genomic analyses of ancient human populations have become feasible partly due to refined sampling methods. The inner part of petrous bones and the cementum layer in teeth roots are currently recognized as the best substrates for such research. We present a comparative analysis of DNA preservation in these two substrates obtained from the same human skulls, across a range of different ages and preservation environments. Both substrates display significantly higher endogenous DNA content (average of 16.4% and 40.0% for teeth and petrous bones, respectively) than parietal skull bone (average of 2.2%). Despite sample-to-sample variation, petrous bone overall performs better than tooth cementum (p = 0.001). This difference, however, is driven largely by a cluster of viking skeletons from one particular locality, showing relatively poor molecular tooth preservation (pros and cons of sampling the different elements. PMID:28129388

  2. Case study: ancient sloth DNA recovered from hairs preserved in paleofeces.

    Science.gov (United States)

    Clack, Andrew A; Macphee, Ross D E; Poinar, Hendrik N

    2012-01-01

    Ancient hair, which has proved to be an excellent source of well-preserved ancient DNA, is often preserved in paleofeces. Here, we separate and wash hair shafts preserved in a paleofecal specimen believed to be from a Darwin's ground sloth, Mylodon darwinii. After extracting DNA from the recovered and cleaned hair using a protocol optimized for DNA extraction from keratinous substrates, we amplify 12S and 16S rDNA sequences from the DNA extract. As expected, the recovered sequences most closely match previously published sequences of M. darwinii. Our results demonstrate that hair preserved in paleofeces, even from temperate cave environments, is an effective source of ancient DNA.

  3. Short sequence effect of ancient DNA on mammoth phylogenetic analyses

    Institute of Scientific and Technical Information of China (English)

    Guilian SHENG; Lianjuan WU; Xindong HOU; Junxia YUAN; Shenghong CHENG; Bojian ZHONG; Xulong LAI

    2009-01-01

    The evolution of Elephantidae has been intensively studied in the past few years, especially after 2006. The molecular approaches have made great contribution to the assumption that the extinct woolly mammoth has a close relationship with the Asian elephant instead of the African elephant. In this study, partial ancient DNA sequences of cytochrome b (cyt b) gene in mitochondrial genome were successfully retrieved from Late Pleistocene Mammuthus primigenius bones collected from Heilongjiang Province in Northeast China. Both the partial and complete homologous cyt b gene sequences and the whole mitochondrial genome sequences extracted from GenBank were aligned and used as datasets for phylogenetic analyses. All of the phylogenetic trees, based on either the partial or the complete cyt b gene, reject the relationship constructed by the whole mitochondrial genome, showing the occurrence of an effect of sequence length of cyt b gene on mammoth phylogenetic analyses.

  4. Ancient DNA reveals past existence of Eurasian lynx in Spain

    DEFF Research Database (Denmark)

    Rodríguez-Varela, R.; García, N.; Nores, C.

    2016-01-01

    The known distribution of the Iberian lynx Lynx pardinus within the Iberian Peninsula since the Middle Pleistocene and the lack of reliable records of Eurasian lynx Lynx lynx in this region have led to the assumption that the Iberian lynx was the sole inhabitant of Iberia. In this study, we...... identified ancient mitochondrial DNA (a total of 337 base pairs from the control region and cytochrome b) from eight northern Iberian lynx remains as Eurasian lynx. These results confirm the presence of Eurasian lynx in northern Iberia from the Pleistocene/Holocene boundary until just a few centuries ago....... The paleontological record and our data indicate a population replacement of the Iberian lynx by the Eurasian lynx during the Pleistocene/Holocene transition in the Cantabrian cornice of Spain. Phylogeographic patterns of Late Pleistocene and Holocene Eurasian lynx from Iberia, France, Italy and Denmark show...

  5. Ancient DNA reveals male diffusion through the Neolithic Mediterranean route.

    Science.gov (United States)

    Lacan, Marie; Keyser, Christine; Ricaut, François-Xavier; Brucato, Nicolas; Duranthon, Francis; Guilaine, Jean; Crubézy, Eric; Ludes, Bertrand

    2011-06-14

    The Neolithic is a key period in the history of the European settlement. Although archaeological and present-day genetic data suggest several hypotheses regarding the human migration patterns at this period, validation of these hypotheses with the use of ancient genetic data has been limited. In this context, we studied DNA extracted from 53 individuals buried in a necropolis used by a French local community 5,000 y ago. The relatively good DNA preservation of the samples allowed us to obtain autosomal, Y-chromosomal, and/or mtDNA data for 29 of the 53 samples studied. From these datasets, we established close parental relationships within the necropolis and determined maternal and paternal lineages as well as the absence of an allele associated with lactase persistence, probably carried by Neolithic cultures of central Europe. Our study provides an integrative view of the genetic past in southern France at the end of the Neolithic period. Furthermore, the Y-haplotype lineages characterized and the study of their current repartition in European populations confirm a greater influence of the Mediterranean than the Central European route in the peopling of southern Europe during the Neolithic transition.

  6. Setting the stage - building and working in an ancient DNA laboratory.

    Science.gov (United States)

    Knapp, Michael; Clarke, Andrew C; Horsburgh, K Ann; Matisoo-Smith, Elizabeth A

    2012-01-20

    With the introduction of next generation high throughput sequencing in 2005 and the resulting revolution in genetics, ancient DNA research has rapidly developed from an interesting but marginal field within evolutionary biology into one that can contribute significantly to our understanding of evolution in general and the development of our own species in particular. While the amount of sequence data available from ancient human, other animal and plant remains has increased dramatically over the past five years, some key limitations of ancient DNA research remain. Most notably, reduction of contamination and the authentication of results are of utmost importance. A number of studies have addressed different aspects of sampling, DNA extraction and DNA manipulation in order to establish protocols that most efficiently generate reproducible and authentic results. As increasing numbers of researchers from different backgrounds become interested in using ancient DNA technology to address key questions, the need for practical guidelines on how to construct and use an ancient DNA facility arises. The aim of this article is therefore to provide practical tips for building a state-of-the-art ancient DNA facility. It is intended to help researchers new to the field of ancient DNA research generally, and those considering the application of next generation sequencing, in their planning process.

  7. Ancient DNA analysis of human remains from the Upper Capital City of Kublai Khan.

    Science.gov (United States)

    Fu, Yuqin; Xie, Chengzhi; Xu, Xuelian; Li, Chunxiang; Zhang, Quanchao; Zhou, Hui; Zhu, Hong

    2009-01-01

    Analysis of DNA from human archaeological remains is a powerful tool for reconstructing ancient events in human history. To help understand the origin of the inhabitants of Kublai Khan's Upper Capital in Inner Mongolia, we analyzed mitochondrial DNA (mtDNA) polymorphisms in 21 ancient individuals buried in the Zhenzishan cemetery of the Upper Capital. MtDNA coding and noncoding region polymorphisms identified in the ancient individuals were characteristic of the Asian mtDNA haplogroups A, B, N9a, C, D, Z, M7b, and M. Phylogenetic analysis of the ancient mtDNA sequences, and comparison with extant reference populations, revealed that the maternal lineages of the population buried in the Zhenzishan cemetery are of Asian origin and typical of present-day Han Chinese, despite the presence of typical European morphological features in several of the skeletons.

  8. mapDamage: testing for damage patterns in ancient DNA sequences

    DEFF Research Database (Denmark)

    Ginolhac, Aurelien; Rasmussen, Morten; Gilbert, M Thomas P;

    2011-01-01

    Ancient DNA extracts consist of a mixture of contaminant DNA molecules, most often originating from environmental microbes, and endogenous fragments exhibiting substantial levels of DNA damage. The latter introduce specific nucleotide misincorporations and DNA fragmentation signatures in sequenci...... of the SAMtools suite and R environment and has been validated on both GNU/Linux and MacOSX operating systems....

  9. Human evolution in Siberia: from frozen bodies to ancient DNA

    Directory of Open Access Journals (Sweden)

    Bouakaze Caroline

    2010-01-01

    Full Text Available Abstract Background The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.g. the precise origin of paternal lineages and the admixture rate with indigenous populations. This study attempts to better understand the origins of the Yakuts by performing genetic analyses on 58 mummified frozen bodies dated from the 15th to the 19th century, excavated from Yakutia (Eastern Siberia. Results High quality data were obtained for the autosomal STRs, Y-chromosomal STRs and SNPs and mtDNA due to exceptional sample preservation. A comparison with the same markers on seven museum specimens excavated 3 to 15 years ago showed significant differences in DNA quantity and quality. Direct access to ancient genetic data from these molecular markers combined with the archaeological evidence, demographical studies and comparisons with 166 contemporary individuals from the same location as the frozen bodies helped us to clarify the microevolution of this intriguing population. Conclusion We were able to trace the origins of the male lineages to a small group of horse-riders from the Cis-Baïkal area. Furthermore, mtDNA data showed that intermarriages between the first settlers with Evenks women led to the establishment of genetic characteristics during the 15th century that are still observed today.

  10. Reconstructing the evolutionary history of China: a caveat about inferences drawn from ancient DNA.

    Science.gov (United States)

    Yao, Yong-Gang; Kong, Qing-Peng; Man, Xiao-Yong; Bandelt, Hans-Jürgen; Zhang, Ya-Ping

    2003-02-01

    The decipherment of the meager information provided by short fragments of ancient mitochondrial DNA (mtDNA) is notoriously difficult but is regarded as a most promising way toward reconstructing the past from the genetic perspective. By haplogroup-specific hypervariable segment (HVS) motif search and matching or near-matching with available modern data sets, most of the ancient mtDNAs can be tentatively assigned to haplogroups, which are often subcontinent specific. Further typing for mtDNA haplogroup-diagnostic coding region polymorphisms, however, is indispensable for establishing the geographic/genetic affinities of ancient samples with less ambiguity. In the present study, we sequenced a fragment (approximately 982 bp) of the mtDNA control region in 76 Han individuals from Taian, Shandong, China, and we combined these data with previously reported samples from Zibo and Qingdao, Shandong. The reanalysis of two previously published ancient mtDNA population data sets from Linzi (same province) then indicates that the ancient populations had features in common with the modern populations from south China rather than any specific affinity to the European mtDNA pool. Our results highlight that ancient mtDNA data obtained under different sampling schemes and subject to potential contamination can easily create the impression of drastic spatiotemporal changes in the genetic structure of a regional population during the past few thousand years if inappropriate methods of data analysis are employed.

  11. Pros and cons of methylation-based enrichment methods for ancient DNA

    DEFF Research Database (Denmark)

    Seguin-Orlando, Andaine; Gamba, Cristina; Der Sarkissian, Clio

    2015-01-01

    The recent discovery that DNA methylation survives in fossil material provides an opportunity for novel molecular approaches in palaeogenomics. Here, we apply to ancient DNA extracts the probe-independent Methylated Binding Domains (MBD)-based enrichment method, which targets DNA molecules contai...

  12. DNA FROM ANCIENT STONE TOOLS AND BONES EXCAVATED AT BUGAS-HOLDING, WYOMING

    Science.gov (United States)

    Traces of DNA may preserve on ancient stone tools. We examined 24 chipped stone artifacts recovered from the Bugas-Holding site in northwestern Wyoming for the presence of DNA residues, and we compared DNA preservation in bones and stone tools from the same stratigraphic context...

  13. Computational analyses of ancient pathogen DNA from herbarium samples: challenges and prospects

    Science.gov (United States)

    Yoshida, Kentaro; Sasaki, Eriko; Kamoun, Sophien

    2015-01-01

    The application of DNA sequencing technology to the study of ancient DNA has enabled the reconstruction of past epidemics from genomes of historically important plant-associated microbes. Recently, the genome sequences of the potato late blight pathogen Phytophthora infestans were analyzed from 19th century herbarium specimens. These herbarium samples originated from infected potatoes collected during and after the Irish potato famine. Herbaria have therefore great potential to help elucidate past epidemics of crops, date the emergence of pathogens, and inform about past pathogen population dynamics. DNA preservation in herbarium samples was unexpectedly good, raising the possibility of a whole new research area in plant and microbial genomics. However, the recovered DNA can be extremely fragmented resulting in specific challenges in reconstructing genome sequences. Here we review some of the challenges in computational analyses of ancient DNA from herbarium samples. We also applied the recently developed linkage method to haplotype reconstruction of diploid or polyploid genomes from fragmented ancient DNA. PMID:26442080

  14. Comparing the performance of three ancient DNA extraction methods for high-throughput sequencing

    DEFF Research Database (Denmark)

    Gamba, Cristina; Hanghøj, Kristian Ebbesen; Gaunitz, Charleen

    2016-01-01

    The DNA molecules that can be extracted from archaeological and palaeontological remains are often degraded and massively contaminated with environmental microbial material. This reduces the efficacy of shotgun approaches for sequencing ancient genomes, despite the decreasing sequencing costs...... of high-throughput sequencing (HTS). Improving the recovery of endogenous molecules from the DNA extraction and purification steps could, thus, help advance the characterization of ancient genomes. Here, we apply the three most commonly used DNA extraction methods to five ancient bone samples spanning...... a ~30 thousand year temporal range and originating from a diversity of environments, from South America to Alaska. We show that methods based on the purification of DNA fragments using silica columns are more advantageous than in solution methods and increase not only the total amount of DNA molecules...

  15. Ligation bias in illumina next-generation DNA libraries: implications for sequencing ancient genomes.

    Science.gov (United States)

    Seguin-Orlando, Andaine; Schubert, Mikkel; Clary, Joel; Stagegaard, Julia; Alberdi, Maria T; Prado, José Luis; Prieto, Alfredo; Willerslev, Eske; Orlando, Ludovic

    2013-01-01

    Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries.

  16. Ligation bias in illumina next-generation DNA libraries: implications for sequencing ancient genomes.

    Directory of Open Access Journals (Sweden)

    Andaine Seguin-Orlando

    Full Text Available Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries.

  17. Paleoparasitological report on Ascaris aDNA from an ancient East Asian sample

    Directory of Open Access Journals (Sweden)

    Chang Seok Oh

    2010-03-01

    Full Text Available In this study, Ascaris DNA was extracted and sequenced from a medieval archaeological sample in Korea. While Ascaris eggs were confirmed to be of human origin by archaeological evidence, it was not possible to pinpoint the exact species due to close genetic relationships among them. Despite this shortcoming, this is the first Ascaris ancient DNA (aDNA report from a medieval Asian country and thus will expand the scope of Ascaris aDNA research.

  18. Stories in Genetic Code. The contribution of ancient DNA studies to anthropology and their ethical implications

    Directory of Open Access Journals (Sweden)

    Cristian M. Crespo

    2010-12-01

    Full Text Available For several decades, biological anthropology has employed different molecular markers in population research. Since 1990 different techniques in molecular biology have been developed allowing preserved DNA extraction and its typification in different samples from museums and archaeological sites. Ancient DNA studies related to archaeological issues are now included in the field of Archaeogenetics. In this work we present some of ancient DNA applications in archaeology. We also discuss advantages and limitations for this kind of research and its relationship with ethic and legal norms.

  19. Ancient DNA from nomads in 2500-year-old archeological sites of Pengyang, China.

    Science.gov (United States)

    Zhao, Yong-Bin; Li, Hong-Jie; Cai, Da-Wei; Li, Chun-Xiang; Zhang, Quan-Chao; Zhu, Hong; Zhou, Hui

    2010-04-01

    Six human remains (dating approximately 2500 years ago) were excavated from Pengyang, China, an area occupied by both ancient nomadic and farming people. The funerary objects found with these remains suggested they were nomads. To further confirm their ancestry, we analyzed both the maternal lineages and paternal lineages of the ancient DNA. From the mitochondrial DNA, six haplotypes were identified as three haplogroups: C, D4 and M10. The haplotype-sharing populations and phylogenetic analyses revealed that these individuals were closely associated with the ancient Xiongnu and modern northern Asians. Single-nucleotide polymorphism analysis of Y chromosomes from four male samples that were typed as haplogroup Q indicated that these people had originated in Siberia. These results show that these ancient people from Pengyang present a close genetic affinity to nomadic people, indicating that northern nomads had reached the Central Plain area of China nearly 2500 years ago.

  20. Ancient DNA, climatic change, and loss of genetic diversity in an endemic Patagonian mammal

    Science.gov (United States)

    Chan, Y.; Lacey, E.; Ramakrishnan, U.; Pearson, O.; Hadly, E.

    2004-12-01

    Understanding the response of animal populations to climatic change is essential for the future maintenance of biodiversity. One question that remains difficult to answer, and is particularly important to conservation, is how animals respond over time scales relevant to evolutionary change. Ancient DNA provides a unique opportunity to track animal response to Holocene climate change and to study species replacement patterns and genetic diversity over time. We used ancient DNA to compare response to climatic change in two species, C. sociabilis and C. haigi, over the last 8,000 years. Our study site, Cueva Traful, is a late-Holocene raptor roost in Parque Nacional Nahuel Huapi, Argentina. A lack of genetic diversity in modern C. sociabilis populations is indicative of past bottleneck events and a previous ancient DNA study found that it had remained genetically identical for at least 1000 years in the face of climatic change and human disturbance. Since Cueva Traful goes back further in time, our first goal was to examine genetic diversity in order to place a longer term historical perspective on the modern bottleneck. The second goal was to compare changes in genetic diversity in C. sociabilis to C. haigi a closely related species that may respond differently to climatic change. The use of ancient DNA presents unique challenges due to low copy number, environmental damage to template, and high contamination risk. Despite these challenges, ancient DNA provides a unique perspective on evolutionary history.

  1. Optimization of the Phenol -Chloroform Silica DNA Extraction Method in Ancient Bones DNA Extraction

    Directory of Open Access Journals (Sweden)

    Morteza Sadeghi

    2014-04-01

    Full Text Available Introduction: DNA extraction from the ancient bones tissues is currently very difficult. Phenol chloroform silica method is one of the methods currently used for this aim. The purpose of this study was to optimize the assessment method. Methods: DNA of 62 bone tissues (average 3-11 years was first extracted with phenol chloroform silica methods and then with changing of some parameters of the methods the extracted DNA was amplified in eight polymorphisms area including FES, F13, D13S317, D16, D5S818, vWA and CD4. Results from samples gained by two methods were compared in acrylamide gel. Results: The average of PCR yield for new method and common method in eight polymorphism regions was 75%, 78%, 81%, 76%, 85%, 71%, 89%, 86% and 64%, 39%, 70%, 49%, 68%, 76%, 71% and 28% respectively. The average of DNA in optimized (in 35l silica density and common method were 267.5 µg/ml with 1.12 purity and 192.76 g/ml with 0.84 purity respectively. Conclusions: According to the findings of this study, it is estimated that longer EDTA attendance is an efficient agent in removing calcium and also adequate density of silica particles can be efficient in removal of PCR inhibitors.

  2. Application and comparison of large-scale solution-based DNA capture-enrichment methods on ancient DNA

    Science.gov (United States)

    Ávila-Arcos, María C.; Cappellini, Enrico; Romero-Navarro, J. Alberto; Wales, Nathan; Moreno-Mayar, J. Víctor; Rasmussen, Morten; Fordyce, Sarah L.; Montiel, Rafael; Vielle-Calzada, Jean-Philippe; Willerslev, Eske; Gilbert, M. Thomas P.

    2011-01-01

    The development of second-generation sequencing technologies has greatly benefitted the field of ancient DNA (aDNA). Its application can be further exploited by the use of targeted capture-enrichment methods to overcome restrictions posed by low endogenous and contaminating DNA in ancient samples. We tested the performance of Agilent's SureSelect and Mycroarray's MySelect in-solution capture systems on Illumina sequencing libraries built from ancient maize to identify key factors influencing aDNA capture experiments. High levels of clonality as well as the presence of multiple-copy sequences in the capture targets led to biases in the data regardless of the capture method. Neither method consistently outperformed the other in terms of average target enrichment, and no obvious difference was observed either when two tiling designs were compared. In addition to demonstrating the plausibility of capturing aDNA from ancient plant material, our results also enable us to provide useful recommendations for those planning targeted-sequencing on aDNA. PMID:22355593

  3. Natural transformation of bacteria by fragmented, damaged and ancient DNA

    DEFF Research Database (Denmark)

    Overballe-Petersen, Søren

    Organisms release DNA both when they live and die. Eventually the DNA disintegrates entirely or it is re-metabolized. There is a constant deposition and decomposition that maintains an environmental pool with large quantities of extracellular DNA, some of which can be thousands of years old...... it by damaged short DNA with abasic sites, crosslinks, and miscoding lesions, which are the most common damages in environmental DNA. This is emphasized by successful natural transformation by 43,000-year-old DNA. We find that the process is a simple variant of natural transformation. On top, we illustrate...... acquire functional genetic signatures of the deeper past. Moreover, not only can old DNA revert microbes to past genotypes, but damaged DNA can also produce new variants of already functional sequences. Besides, DNA fragments carry potential to combine functional domains in new ways. The identified novel...

  4. Pros and cons of methylation-based enrichment methods for ancient DNA

    DEFF Research Database (Denmark)

    Seguin-Orlando, Andaine; Gamba, Cristina; Der Sarkissian, Clio;

    2015-01-01

    The recent discovery that DNA methylation survives in fossil material provides an opportunity for novel molecular approaches in palaeogenomics. Here, we apply to ancient DNA extracts the probe-independent Methylated Binding Domains (MBD)-based enrichment method, which targets DNA molecules...... containing methylated CpGs. Using remains of a Palaeo-Eskimo Saqqaq individual, woolly mammoths, polar bears and two equine species, we confirm that DNA methylation survives in a variety of tissues, environmental contexts and over a large temporal range (4,000 to over 45,000 years before present). MBD...... enrichment, however, appears principally biased towards the recovery of CpG-rich and long DNA templates and is limited by the fast post-mortem cytosine deamination rates of methylated epialleles. This method, thus, appears only appropriate for the analysis of ancient methylomes from very well preserved...

  5. Use of RAPD and PCR double amplification in the study of ancient DNA

    Directory of Open Access Journals (Sweden)

    F. Balzano

    2011-01-01

    Full Text Available This project analysed the DNA extracted from bones of ancient sheep which have been brought to light in Sardinian different archaeological sites. In order to better analyse this highly fragmented DNA, a double amplification technique was chosen. The first approach consisted of RAPD-PCR abd the second one in classic PCR. The RAPD-PCR amplified random fragments and allowed the production of numerous amplicons. The products of RAPD amplification have been amplified, more specifically, by the second PCR using primers for a sequence of 176 bp of mitochondrial D-loop region. These DNA fragments have been sequenced and the sequence analysis has confirmed that it belonged to Ovis aries. Consequently, this provedure can be considered a valid tool to perform amplification of degraded DNA, such as ancient DNA.

  6. Comparing the performance of three ancient DNA extraction methods for high-throughput sequencing.

    Science.gov (United States)

    Gamba, Cristina; Hanghøj, Kristian; Gaunitz, Charleen; Alfarhan, Ahmed H; Alquraishi, Saleh A; Al-Rasheid, Khaled A S; Bradley, Daniel G; Orlando, Ludovic

    2016-03-01

    The DNA molecules that can be extracted from archaeological and palaeontological remains are often degraded and massively contaminated with environmental microbial material. This reduces the efficacy of shotgun approaches for sequencing ancient genomes, despite the decreasing sequencing costs of high-throughput sequencing (HTS). Improving the recovery of endogenous molecules from the DNA extraction and purification steps could, thus, help advance the characterization of ancient genomes. Here, we apply the three most commonly used DNA extraction methods to five ancient bone samples spanning a ~30 thousand year temporal range and originating from a diversity of environments, from South America to Alaska. We show that methods based on the purification of DNA fragments using silica columns are more advantageous than in solution methods and increase not only the total amount of DNA molecules retrieved but also the relative importance of endogenous DNA fragments and their molecular diversity. Therefore, these methods provide a cost-effective solution for downstream applications, including DNA sequencing on HTS platforms.

  7. DNA in ancient bone - Where is it located and how should we extract it?

    DEFF Research Database (Denmark)

    Campos, Paula; Craig, Oliver E.; Turner-Walker, Gordon

    2011-01-01

    . The question arises as to whether this may be due to post-collection preservation or just an artefact of the extraction methods used in these different studies? In an attempt to resolve these questions, we examine the efficacy of DNA extraction methods, and the quality and quantity of DNA recovered from both......Despite the widespread use of bones in ancient DNA (aDNA) studies, relatively little concrete information exists in regard to how the DNA in mineralised collagen degrades, or where it survives in the material's architecture. While, at the macrostructural level, physical exclusion of microbes...... and other external contaminants may be an important feature, and, at the ultrastructural level, the adsorption of DNA to hydroxyapatite and/or binding of DNA to Type I collagen may stabilise the DNA, the relative contribution of each, and what other factors may be relevant, are unclear...

  8. Recharacterization of ancient DNA miscoding lesions: insights in the era of sequencing-by-synthesis

    DEFF Research Database (Denmark)

    Gilbert, M Thomas P; Binladen, Jonas; Miller, Webb;

    2007-01-01

    , and subsequently be interpreted to enable characterization of the aDNA damage behind the observed phenotypes. Through comparative analyses on 390,965 bp of modern chloroplast and 131,474 bp of ancient woolly mammoth GS20 sequence data we conclusively demonstrate that in this sample at least, a permafrost preserved...

  9. Roche genome sequencer FLX based high-throughput sequencing of ancient DNA

    DEFF Research Database (Denmark)

    Alquezar-Planas, David E; Fordyce, Sarah Louise

    2012-01-01

    Since the development of so-called "next generation" high-throughput sequencing in 2005, this technology has been applied to a variety of fields. Such applications include disease studies, evolutionary investigations, and ancient DNA. Each application requires a specialized protocol to ensure tha...

  10. Combining bleach and mild predigestion improves ancient DNA recovery from bones

    DEFF Research Database (Denmark)

    Boessenkool, Sanne; Hanghøj, Kristian Ebbesen; Nistelberger, Heidi M.

    2017-01-01

    aimed to improve ancient DNA recovery before library amplification have recently been developed. Here, we test the effects of combining two of such protocols, a bleach wash and a predigestion step, on 12 bone samples of Atlantic cod and domestic horse aged 750-1350 cal. years before present. Using high...

  11. DNA extraction of ancient animal hard tissue samples via adsorption to silica particles.

    Science.gov (United States)

    Rohland, Nadin

    2012-01-01

    A large number of subfossil and more recent skeletal remains, many of which are stored in museums and private collections, are potentially accessible for DNA sequence analysis. In order to extract the small amount of DNA preserved in these specimens, an efficient DNA release and purification method is required. In this chapter, I describe an efficient and straightforward purification and concentration method that uses DNA adsorption to a solid surface of silica particles. Comparative analysis of extraction methods has shown that this method works reliably for ancient as well as younger, museum-preserved specimens.

  12. Technical note: improved DNA extraction from ancient bones using silica-based spin columns.

    Science.gov (United States)

    Yang, D Y; Eng, B; Waye, J S; Dudar, J C; Saunders, S R

    1998-04-01

    We describe a simple method for extracting polymerase chain reaction-amplifiable DNA from ancient bones without the use of organic solvents. Bone powders are digested with proteinase K, and the DNA is purified directly using silica-based spin columns (QIAquick3, QIAGEN). The efficiency of this protocol is demonstrated using human bone samples ranging in age from 15 to 5,000 years old.

  13. Attempted DNA extraction from a Rancho La Brea Columbian mammoth (Mammuthus columbi): prospects for ancient DNA from asphalt deposits.

    Science.gov (United States)

    Gold, David A; Robinson, Jacqueline; Farrell, Aisling B; Harris, John M; Thalmann, Olaf; Jacobs, David K

    2014-02-01

    Fossil-bearing asphalt deposits are an understudied and potentially significant source of ancient DNA. Previous attempts to extract DNA from skeletons preserved at the Rancho La Brea tar pits in Los Angeles, California, have proven unsuccessful, but it is unclear whether this is due to a lack of endogenous DNA, or if the problem is caused by asphalt-mediated inhibition. In an attempt to test these hypotheses, a recently recovered Columbian mammoth (Mammuthus columbi) skeleton with an unusual pattern of asphalt impregnation was studied. Ultimately, none of the bone samples tested successfully amplified M. columbi DNA. Our work suggests that reagents typically used to remove asphalt from ancient samples also inhibit DNA extraction. Ultimately, we conclude that the probability of recovering ancient DNA from fossils in asphalt deposits is strongly (perhaps fatally) hindered by the organic compounds that permeate the bones and that at the Rancho La Brea tar pits, environmental conditions might not have been ideal for the general preservation of genetic material.

  14. High-Resolution Analysis of Cytosine Methylation in Ancient DNA

    OpenAIRE

    Llamas, Bastien; Holland, Michelle L.; Chen, Kefei; Jennifer E Cropley; Cooper, Alan; Suter, Catherine M

    2012-01-01

    Epigenetic changes to gene expression can result in heritable phenotypic characteristics that are not encoded in the DNA itself, but rather by biochemical modifications to the DNA or associated chromatin proteins. Interposed between genes and environment, these epigenetic modifications can be influenced by environmental factors to affect phenotype for multiple generations. This raises the possibility that epigenetic states provide a substrate for natural selection, with the potential to parti...

  15. Crosslinks rather than strand breaks determine access to ancient DNA sequences from frozen sediments.

    Science.gov (United States)

    Hansen, Anders J; Mitchell, David L; Wiuf, Carsten; Paniker, Lakshmi; Brand, Tina B; Binladen, Jonas; Gilichinsky, David A; Rønn, Regin; Willerslev, Eske

    2006-06-01

    Diagenesis was studied in DNA obtained from Siberian permafrost (permanently frozen soil) ranging from 10,000 to 400,000 years in age. Despite optimal preservation conditions, we found the sedimentary DNA to be severely modified by interstrand crosslinks; single- and double-stranded breaks; and freely exposed sugar, phosphate, and hydroxyl groups. Intriguingly, interstrand crosslinks were found to accumulate approximately 100 times faster than single-stranded breaks, suggesting that crosslinking rather than depurination is the primary limiting factor for ancient DNA amplification under frozen conditions. The results question the reliability of the commonly used models relying on depurination kinetics for predicting the long-term survival of DNA under permafrost conditions and suggest that new strategies for repair of ancient DNA must be considered if the yield of amplifiable DNA from permafrost sediments is to be significantly increased. Using the obtained rate constant for interstrand crosslinks the maximal survival time of amplifiable 120-bp fragments of bacterial 16S ribosomal DNA was estimated to be approximately 400,000 years. Additionally, a clear relationship was found between DNA damage and sample age, contradicting previously raised concerns about the possible leaching of free DNA molecules between permafrost layers.

  16. Ancient DNA extracted from Danish aurochs (Bos primigenius)

    DEFF Research Database (Denmark)

    Nielsen, Peter Gravlund; Aaris-Sørensen, Kim; Hofreiter, Michael

    2012-01-01

    We extracted DNA from 39 Danish aurochs specimens and successfully amplified and sequenced a 252 base pair long fragment of the multivariable region I of the mitochondrial control region from 11 specimens. The sequences from these specimens dated back to 9830-2865 14C yr BP and represent the first...... study of genetic variation of Danish aurochs. In addition, for all specimens we address correlations between the ability to obtain DNA sequences and various parameters such as the age of the sample, the collagen content, the museum storage period, Danish geography and whether the specimens were found...

  17. Ancient DNA in human bone remains from Pompeii archaeological site.

    Science.gov (United States)

    Cipollaro, M; Di Bernardo, G; Galano, G; Galderisi, U; Guarino, F; Angelini, F; Cascino, A

    1998-06-29

    aDNA extraction and amplification procedures have been optimized for Pompeian human bone remains whose diagenesis has been determined by histological analysis. Single copy genes amplification (X and Y amelogenin loci and Y specific alphoid repeat sequences) have been performed and compared with anthropometric data on sexing.

  18. Characterising the potential of sheep wool for ancient DNA analyses

    DEFF Research Database (Denmark)

    Brandt, Luise Ørsted; Tranekjer, Lena D.; Mannering, Ulla;

    2011-01-01

    can be PCR-amplified from wool derived from a variety of breeds, regardless of the body location or natural pigmentation. Furthermore, although DNA can be PCR-amplified from wool dyed with one of four common plant dyes (tansy, woad, madder, weld), the use of mordants such as alum or iron leads...

  19. Ancient DNA: Would the Real Neandertal Please Stand up?

    DEFF Research Database (Denmark)

    Cooper, Alan; Drummond, Alexei J.; Willerslev, Eske

    2004-01-01

    Mitochondrial DNA sequences recovered from eight Neandertal specimens cannot be detected in either early fossil Europeans or in modern populations. This indicates that, if Neandertals made any genetic contribution at all to modern humans, it must have been limited, though the extent of the contri...

  20. A preliminary analysis of the DNA and diet of the extinct Beothuk: a systematic approach to ancient human DNA

    DEFF Research Database (Denmark)

    Kuch, Melanie; Gröcke, Darren R; Knyf, Martin C

    2007-01-01

    We have used a systematic protocol for extracting, quantitating, sexing and validating ancient human mitochondrial and nuclear DNA of one male and one female Beothuk, a Native American population from Newfoundland, which became extinct approximately 180 years ago. They carried mtDNA haplotypes......, and that their water sources were pooled or stored water. Both mtDNA sequence data and Y SNP data hint at possible gene flow or a common ancestral population for both the Beothuk and the current day Mikmaq, but more importantly the data do not lend credence to the proposed idea that the Beothuk (specifically......, Nonosabasut) were of admixed (European-Native American) descent. We also analyzed patterns of DNA damage in the clones of authentic mtDNA sequences; there is no tendency for DNA damage to occur preferentially at previously defined mutational hotspots, suggesting that such mutational hotspots...

  1. Analyses of DNA from ancient bones of a pre-Columbian Cuban woman and a child

    Directory of Open Access Journals (Sweden)

    Ricardo Lleonart

    1999-09-01

    Full Text Available Molecular anthropology has brought new possibilities into the study of ancient human populations. Amplification of chromosomal short tandem repeat (STR loci and mitochondrial DNA (mtDNA has been successfully employed in analyses of ancient bone material. Although several studies have reported on continental Amerindian populations, none have addressed the ancient populations inhabiting the Caribbean islands. We used STR and mtDNA analyses to study the skeletal remains of a Cuban Ciboney female adult holding an infant. Results showed that for the STR analyzed the skeletal remains shared common alleles, suggesting a relationship. Mitochondrial DNA analysis showed sequence identity, thus corroborating a possible mother-child relationship. The mtDNA sequence grouped these remains into haplogroup A, commonly found in Amerindian populations. Based on these results, we speculated on a South American origin of pre-Columbian Antilles populations and possible infanticide practices in these populations. This constitutes the first report on DNA analysis of ancient pre-Columbian Cuban populations.A antropologia molecular trouxe novas possibilidades para o estudo de populações humanas antigas. A amplificação de loci em pequenos segmentos cromossômicos repetidos (short tandem repeat, STR e de DNA mitocondrial (mtDNA tem sido empregada com sucesso em análises de material ósseo antigo. Embora vários estudos tenham sido publicados a respeito de populações ameríndias continentais, nenhum estudou as populações antigas que habitavam as ilhas do Caribe. Nós usamos análise de STR e mtDNA para estudar os restos de ossos de uma mulher adulta da tribo Ciboney cubana carregando uma criança. Os resultados mostraram que para o STR analisado os restos ósseos compartilhavam alelos comuns, sugerindo um parentesco. A análise de mtDNA mostrou identidade de seqüência, corroborando assim uma possível relação mãe-filho. A seqüência de mtDNA alocou esses

  2. Application of Ancient DNA Methods to the Study of the Transatlantic Slave Trade

    DEFF Research Database (Denmark)

    Sandoval Velasco, Marcela

    these limitations. Rigorous laboratory procedures, optimized capture enrichment methods coupled to high-throughput sequencing platforms, and expanding modern reference datasets have enabled the generation of complete ancient genomes from numerous extinct and extant species, including humans and hominins...... suboptimal conditions. However, experimental and analytical methods have been developed to overcome these limitations. Rigorous laboratory procedures, optimized capture enrichment methods coupled to high-throughput sequencing platforms, and expanding modern reference datasets have enabled the generation...... of complete ancient genomes from numerous extinct and extant species, including humans and hominins. In addition, the field has gradually opened the opportunity to study human populations through history. In this thesis I have applied, tested and investigated the performance of different ancient DNA...

  3. Using ancient DNA to study the origins and dispersal of ancestral Polynesian chickens across the Pacific.

    Science.gov (United States)

    Thomson, Vicki A; Lebrasseur, Ophélie; Austin, Jeremy J; Hunt, Terry L; Burney, David A; Denham, Tim; Rawlence, Nicolas J; Wood, Jamie R; Gongora, Jaime; Girdland Flink, Linus; Linderholm, Anna; Dobney, Keith; Larson, Greger; Cooper, Alan

    2014-04-01

    The human colonization of Remote Oceania remains one of the great feats of exploration in history, proceeding east from Asia across the vast expanse of the Pacific Ocean. Human commensal and domesticated species were widely transported as part of this diaspora, possibly as far as South America. We sequenced mitochondrial control region DNA from 122 modern and 22 ancient chicken specimens from Polynesia and Island Southeast Asia and used these together with Bayesian modeling methods to examine the human dispersal of chickens across this area. We show that specific techniques are essential to remove contaminating modern DNA from experiments, which appear to have impacted previous studies of Pacific chickens. In contrast to previous reports, we find that all ancient specimens and a high proportion of the modern chickens possess a group of unique, closely related haplotypes found only in the Pacific. This group of haplotypes appears to represent the authentic founding mitochondrial DNA chicken lineages transported across the Pacific, and allows the early dispersal of chickens across Micronesia and Polynesia to be modeled. Importantly, chickens carrying this genetic signature persist on several Pacific islands at high frequencies, suggesting that the original Polynesian chicken lineages may still survive. No early South American chicken samples have been detected with the diagnostic Polynesian mtDNA haplotypes, arguing against reports that chickens provide evidence of Polynesian contact with pre-European South America. Two modern specimens from the Philippines carry haplotypes similar to the ancient Pacific samples, providing clues about a potential homeland for the Polynesian chicken.

  4. Evidence of ancient DNA reveals the first European lineage in Iron Age Central China.

    Science.gov (United States)

    Xie, C Z; Li, C X; Cui, Y Q; Zhang, Q C; Fu, Y Q; Zhu, H; Zhou, H

    2007-07-01

    Various studies on ancient DNA have attempted to reconstruct population movement in Asia, with much interest focused on determining the arrival of European lineages in ancient East Asia. Here, we discuss our analysis of the mitochondrial DNA of human remains excavated from the Yu Hong tomb in Taiyuan, China, dated 1400 years ago. The burial style of this tomb is characteristic of Central Asia at that time. Our analysis shows that Yu Hong belonged to the haplogroup U5, one of the oldest western Eurasian-specific haplogroups, while his wife can be classified as haplogroup G, the type prevalent in East Asia. Our findings show that this man with European lineage arrived in Taiyuan approximately 1400 years ago, and most probably married a local woman. Haplogroup U5 was the first west Eurasian-specific lineage to be found in the central part of ancient China, and Taiyuan may be the easternmost location of the discovered remains of European lineage in ancient China.

  5. Ancient DNA from 8400 Year-Old Catalhoyuk Wheat: Implications for the Origin of Neolithic Agriculture.

    Directory of Open Access Journals (Sweden)

    Hatice Bilgic

    Full Text Available Human history was transformed with the advent of agriculture in the Fertile Crescent with wheat as one of the founding crops. Although the Fertile Crescent is renowned as the center of wheat domestication, archaeological studies have shown the crucial involvement of Çatalhöyük in this process. This site first gained attention during the 1961-65 excavations due to the recovery of primitive hexaploid wheat. However, despite the seeds being well preserved, a detailed archaeobotanical description of the samples is missing. In this article, we report on the DNA isolation, amplification and sequencing of ancient DNA of charred wheat grains from Çatalhöyük and other Turkish archaeological sites and the comparison of these wheat grains with contemporary wheat species including T. monococcum, T. dicoccum, T. dicoccoides, T. durum and T. aestivum at HMW glutenin protein loci. These ancient samples represent the oldest wheat sample sequenced to date and the first ancient wheat sample from the Middle East. Remarkably, the sequence analysis of the short DNA fragments preserved in seeds that are approximately 8400 years old showed that the Çatalhöyük wheat stock contained hexaploid wheat, which is similar to contemporary hexaploid wheat species including both naked (T. aestivum and hulled (T. spelta wheat. This suggests an early transitory state of hexaploid wheat agriculture from the Fertile Crescent towards Europe spanning present-day Turkey.

  6. Joint Estimation of Contamination, Error and Demography for Nuclear DNA from Ancient Humans.

    Directory of Open Access Journals (Sweden)

    Fernando Racimo

    2016-04-01

    Full Text Available When sequencing an ancient DNA sample from a hominin fossil, DNA from present-day humans involved in excavation and extraction will be sequenced along with the endogenous material. This type of contamination is problematic for downstream analyses as it will introduce a bias towards the population of the contaminating individual(s. Quantifying the extent of contamination is a crucial step as it allows researchers to account for possible biases that may arise in downstream genetic analyses. Here, we present an MCMC algorithm to co-estimate the contamination rate, sequencing error rate and demographic parameters-including drift times and admixture rates-for an ancient nuclear genome obtained from human remains, when the putative contaminating DNA comes from present-day humans. We assume we have a large panel representing the putative contaminant population (e.g. European, East Asian or African. The method is implemented in a C++ program called 'Demographic Inference with Contamination and Error' (DICE. We applied it to simulations and genome data from ancient Neanderthals and modern humans. With reasonable levels of genome sequence coverage (>3X, we find we can recover accurate estimates of all these parameters, even when the contamination rate is as high as 50%.

  7. Using ancient DNA and coalescent-based methods to infer extinction.

    Science.gov (United States)

    Chang, Dan; Shapiro, Beth

    2016-02-01

    DNA sequences extracted from preserved remains can add considerable resolution to inference of past population dynamics. For example, coalescent-based methods have been used to correlate declines in some arctic megafauna populations with habitat fragmentation during the last ice age. These methods, however, often fail to detect population declines preceding extinction, most likely owing to a combination of sparse sampling, uninformative genetic markers, and models that cannot account for the increasingly structured nature of populations as habitats decline. As ancient DNA research expands to include full-genome analyses, these data will provide greater resolution of the genomic consequences of environmental change and the genetic signatures of extinction.

  8. Taming the Past: Ancient DNA and the Study of Animal Domestication.

    Science.gov (United States)

    MacHugh, David E; Larson, Greger; Orlando, Ludovic

    2017-02-08

    During the last decade, ancient DNA research has been revolutionized by the availability of increasingly powerful DNA sequencing and ancillary genomics technologies, giving rise to the new field of paleogenomics. In this review, we show how our understanding of the genetic basis of animal domestication and the origins and dispersal of livestock and companion animals during the Upper Paleolithic and Neolithic periods is being rapidly transformed through new scientific knowledge generated with paleogenomic methods. These techniques have been particularly informative in revealing high-resolution patterns of artificial and natural selection and evidence for significant admixture between early domestic animal populations and their wild congeners.

  9. Recent advances in ancient DNA research and their implications for archaeobotany

    DEFF Research Database (Denmark)

    Brown, Terence A.; Cappellini, Enrico; Kistler, Logan

    2015-01-01

    The scope and ambition of biomolecular archaeology is undergoing rapid change due to the development of new ‘next generation’ sequencing (NGS) methods for analysis of ancient DNA in archaeological specimens. These methods have not yet been applied extensively to archaeobotanical material...... but their utility has been demonstrated with desiccated, waterlogged and charred remains. The future use of NGS is likely to open up new areas of investigation that have been difficult or impossible with the traditional approach to aDNA sequencing. Species identification should become more routine...

  10. Insights into early pig domestication provided by ancient DNA analysis

    Science.gov (United States)

    Caliebe, Amke; Nebel, Almut; Makarewicz, Cheryl; Krawczak, Michael; Krause-Kyora, Ben

    2017-01-01

    Pigs (Sus scrofa) were first domesticated between 8,500 and 8,000 cal BC in the Near East, from where they were subsequently brought into Europe by agriculturalists. Soon after the arrival of the first domestic pigs in northern Europe (~4500 BC), farmers are thought to have started to incorporate local wild boars into their swine herds. This husbandry strategy ultimately resulted in the domestication of European wild boars. Here, we set out to provide a more precise geographic and temporal framework of the early management of suid populations in northern Europe, drawing upon mitochondrial DNA haplotype data from 116 Neolithic Sus specimens. We developed a quantitative mathematical model tracing the haplotypes of the domestic pigs back to their most likely geographic origin. Our modelling results suggest that, between 5000 and 4000 BC, almost all matrilines in the north originated from domesticated animals from the south of central Europe. In the following period (4000–3000 BC), an estimated 78–100% of domesticates in the north were of northern matrilineal origin, largely from local wild boars. These findings point towards a dramatic change in suid management strategies taking place throughout south-central and northern Europe after 4000 BC. PMID:28300151

  11. Experimental conditions improving in-solution target enrichment for ancient DNA.

    Science.gov (United States)

    Cruz-Dávalos, Diana I; Llamas, Bastien; Gaunitz, Charleen; Fages, Antoine; Gamba, Cristina; Soubrier, Julien; Librado, Pablo; Seguin-Orlando, Andaine; Pruvost, Mélanie; Alfarhan, Ahmed H; Alquraishi, Saleh A; Al-Rasheid, Khaled A S; Scheu, Amelie; Beneke, Norbert; Ludwig, Arne; Cooper, Alan; Willerslev, Eske; Orlando, Ludovic

    2016-08-27

    High-throughput sequencing has dramatically fostered ancient DNA research in recent years. Shotgun sequencing, however, does not necessarily appear as the best-suited approach due to the extensive contamination of samples with exogenous environmental microbial DNA. DNA capture-enrichment methods represent cost-effective alternatives that increase the sequencing focus on the endogenous fraction, whether it is from mitochondrial or nuclear genomes, or parts thereof. Here, we explored experimental parameters that could impact the efficacy of MYbaits in-solution capture assays of ~5000 nuclear loci or the whole genome. We found that varying quantities of the starting probes had only moderate effect on capture outcomes. Starting DNA, probe tiling, the hybridization temperature and the proportion of endogenous DNA all affected the assay, however. Additionally, probe features such as their GC content, number of CpG dinucleotides, sequence complexity and entropy and self-annealing properties need to be carefully addressed during the design stage of the capture assay. The experimental conditions and probe molecular features identified in this study will improve the recovery of genetic information extracted from degraded and ancient remains.

  12. Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary.

    Science.gov (United States)

    Almathen, Faisal; Charruau, Pauline; Mohandesan, Elmira; Mwacharo, Joram M; Orozco-terWengel, Pablo; Pitt, Daniel; Abdussamad, Abdussamad M; Uerpmann, Margarethe; Uerpmann, Hans-Peter; De Cupere, Bea; Magee, Peter; Alnaqeeb, Majed A; Salim, Bashir; Raziq, Abdul; Dessie, Tadelle; Abdelhadi, Omer M; Banabazi, Mohammad H; Al-Eknah, Marzook; Walzer, Chris; Faye, Bernard; Hofreiter, Michael; Peters, Joris; Hanotte, Olivier; Burger, Pamela A

    2016-06-14

    Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species' range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the "restocking from the wild" hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments.

  13. News from the west: ancient DNA from a French megalithic burial chamber.

    Science.gov (United States)

    Deguilloux, Marie-France; Soler, Ludovic; Pemonge, Marie-Hélène; Scarre, Chris; Joussaume, Roger; Laporte, Luc

    2011-01-01

    Recent paleogenetic studies have confirmed that the spread of the Neolithic across Europe was neither genetically nor geographically uniform. To extend existing knowledge of the mitochondrial European Neolithic gene pool, we examined six samples of human skeletal material from a French megalithic long mound (c.4200 cal BC). We retrieved HVR-I sequences from three individuals and demonstrated that in the Neolithic period the mtDNA haplogroup N1a, previously only known in central Europe, was as widely distributed as western France. Alternative scenarios are discussed in seeking to explain this result, including Mesolithic ancestry, Neolithic demic diffusion, and long-distance matrimonial exchanges. In light of the limited Neolithic ancient DNA (aDNA) data currently available, we observe that all three scenarios appear equally consistent with paleogenetic and archaeological data. In consequence, we advocate caution in interpreting aDNA in the context of the Neolithic transition in Europe. Nevertheless, our results strengthen conclusions demonstrating genetic discontinuity between modern and ancient Europeans whether through migration, demographic or selection processes, or social practices.

  14. The characterization of Helicobacter pylori DNA associated with ancient human remains recovered from a Canadian glacier.

    Directory of Open Access Journals (Sweden)

    Treena Swanston

    Full Text Available Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of nearly half of the world's population. Genotypic characterization of H. pylori strains involves the analysis of virulence-associated genes, such as vacA, which has multiple alleles. Previous phylogenetic analyses have revealed a connection between modern H. pylori strains and the movement of ancient human populations. In this study, H. pylori DNA was amplified from the stomach tissue of the Kwäday Dän Ts'ìnchi individual. This ancient individual was recovered from the Samuel Glacier in Tatshenshini-Alsek Park, British Columbia, Canada on the traditional territory of the Champagne and Aishihik First Nations and radiocarbon dated to a timeframe of approximately AD 1670 to 1850. This is the first ancient H. pylori strain to be characterized with vacA sequence data. The Tatshenshini H. pylori strain has a potential hybrid vacA m2a/m1d middle (m region allele and a vacA s2 signal (s region allele. A vacA s2 allele is more commonly identified with Western strains, and this suggests that European strains were present in northwestern Canada during the ancient individual's time. Phylogenetic analysis indicated that the vacA m1d region of the ancient strain clusters with previously published novel Native American strains that are closely related to Asian strains. This indicates a past connection between the Kwäday Dän Ts'ìnchi individual and the ancestors who arrived in the New World thousands of years ago.

  15. Ancient DNA reveals traces of Iberian Neolithic and Bronze Age lineages in modern Iberian horses

    DEFF Research Database (Denmark)

    Lira, Jaime; Linderholm, Anna; Olaria, Carmen

    2010-01-01

    Multiple geographical regions have been proposed for the domestication of Equus caballus. It has been suggested, based on zooarchaeological and genetic analyses that wild horses from the Iberian Peninsula were involved in the process, and the overrepresentation of mitochondrial D1 cluster in modern...... Iberian horses supports this suggestion. To test this hypothesis, we analysed mitochondrial DNA from 22 ancient Iberian horse remains belonging to the Neolithic, the Bronze Age and the Middle Ages, against previously published sequences. Only the medieval Iberian sequence appeared in the D1 group....... Neolithic and Bronze Age sequences grouped in other clusters, one of which (Lusitano group C) is exclusively represented by modern horses of Iberian origin. Moreover, Bronze Age Iberian sequences displayed the lowest nucleotide diversity values when compared with modern horses, ancient wild horses and other...

  16. Phylogenetic Analysis of mtDNA from the Ancient Human of Yuan Dynasty in Inner Mongolia in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study of the genetic structure of an ancient human excavated from the Yikeshu site of Yuanshangdu ancient city in Inner Mongolia and the relationships between the ancient population and the extant populations was carried out.Sequences of the control region and coding region of mtDNA from the ancient human were analyzed by using direct sequencing and restriction-fragment length polymorphism (RFLP) methods. Phylogenetic analysis and multidimensional scaling analysis were also performed on the mtDNA data of the ancient population and 12 extant populations. These results show that the ancient individuals of Yikeshu site can be assigned to D, G, B and Z haplogroups that are prevalent in Duars and Mongolians from Inner Mongolia. The ancient population is also closer to Duar and Mongolian populations in genetic distance than other compared populations. This study reveals that the ancient population from Yikeshu site in the Yuan Dynasty shares a common ancestor with Mongolic-speaking Daur and Mongolian tribes.

  17. Contesting the presence of wheat in the British Isles 8,000 years ago by assessing ancient DNA authenticity from low-coverage data.

    Science.gov (United States)

    Weiß, Clemens L; Dannemann, Michael; Prüfer, Kay; Burbano, Hernán A

    2015-11-03

    Contamination with exogenous DNA is a constant hazard to ancient DNA studies, since their validity greatly depend on the ancient origin of the retrieved sequences. Since contamination occurs sporadically, it is fundamental to show positive evidence for the authenticity of ancient DNA sequences even when preventive measures to avoid contamination are implemented. Recently the presence of wheat in the United Kingdom 8000 years before the present has been reported based on an analysis of sedimentary ancient DNA (Smith et al. 2015). Smith et al. did not present any positive evidence for the authenticity of their results due to the small number of sequencing reads that were confidently assigned to wheat. We developed a computational method that compares postmortem damage patterns of a test dataset with bona fide ancient and modern DNA. We applied this test to the putative wheat DNA and find that these reads are most likely not of ancient origin.

  18. Investigating the global dispersal of chickens in prehistory using ancient mitochondrial DNA signatures.

    Directory of Open Access Journals (Sweden)

    Alice A Storey

    Full Text Available Data from morphology, linguistics, history, and archaeology have all been used to trace the dispersal of chickens from Asian domestication centers to their current global distribution. Each provides a unique perspective which can aid in the reconstruction of prehistory. This study expands on previous investigations by adding a temporal component from ancient DNA and, in some cases, direct dating of bones of individual chickens from a variety of sites in Europe, the Pacific, and the Americas. The results from the ancient DNA analyses of forty-eight archaeologically derived chicken bones provide support for archaeological hypotheses about the prehistoric human transport of chickens. Haplogroup E mtDNA signatures have been amplified from directly dated samples originating in Europe at 1000 B.P. and in the Pacific at 3000 B.P. indicating multiple prehistoric dispersals from a single Asian centre. These two dispersal pathways converged in the Americas where chickens were introduced both by Polynesians and later by Europeans. The results of this study also highlight the inappropriate application of the small stretch of D-loop, traditionally amplified for use in phylogenetic studies, to understanding discrete episodes of chicken translocation in the past. The results of this study lead to the proposal of four hypotheses which will require further scrutiny and rigorous future testing.

  19. Biomolecular identification of ancient Mycobacterium tuberculosis complex DNA in human remains from Britain and continental Europe.

    Science.gov (United States)

    Müller, Romy; Roberts, Charlotte A; Brown, Terence A

    2014-02-01

    Tuberculosis is known to have afflicted humans throughout history and re-emerged towards the end of the 20th century, to an extent that it was declared a global emergency in 1993. The aim of this study was to apply a rigorous analytical regime to the detection of Mycobacterium tuberculosis complex (MTBC) DNA in 77 bone and tooth samples from 70 individuals from Britain and continental Europe, spanning the 1st-19th centuries AD. We performed the work in dedicated ancient DNA facilities designed to prevent all types of modern contamination, we checked the authenticity of all products obtained by the polymerase chain reaction, and we based our conclusions on up to four replicate experiments for each sample, some carried out in an independent laboratory. We identified 12 samples that, according to our strict criteria, gave definite evidence for the presence of MTBC DNA, and another 22 that we classified as "probable" or "possible." None of the definite samples came from vertebrae displaying lesions associated with TB. Instead, eight were from ribs displaying visceral new bone formation, one was a tooth from a skeleton with rib lesions, one was taken from a skeleton with endocranial lesions, one from an individual with lesions to the sacrum and sacroiliac joint and the last was from an individual with no lesions indicative of TB or possible TB. Our results add to information on the past temporal and geographical distribution of TB and affirm the suitability of ribs for studying ancient TB.

  20. Investigating the Global Dispersal of Chickens in Prehistory Using Ancient Mitochondrial DNA Signatures

    Science.gov (United States)

    Storey, Alice A.; Athens, J. Stephen; Bryant, David; Carson, Mike; Emery, Kitty; deFrance, Susan; Higham, Charles; Huynen, Leon; Intoh, Michiko; Jones, Sharyn; Kirch, Patrick V.; Ladefoged, Thegn; McCoy, Patrick; Morales-Muñiz, Arturo; Quiroz, Daniel; Reitz, Elizabeth; Robins, Judith; Walter, Richard; Matisoo-Smith, Elizabeth

    2012-01-01

    Data from morphology, linguistics, history, and archaeology have all been used to trace the dispersal of chickens from Asian domestication centers to their current global distribution. Each provides a unique perspective which can aid in the reconstruction of prehistory. This study expands on previous investigations by adding a temporal component from ancient DNA and, in some cases, direct dating of bones of individual chickens from a variety of sites in Europe, the Pacific, and the Americas. The results from the ancient DNA analyses of forty-eight archaeologically derived chicken bones provide support for archaeological hypotheses about the prehistoric human transport of chickens. Haplogroup E mtDNA signatures have been amplified from directly dated samples originating in Europe at 1000 B.P. and in the Pacific at 3000 B.P. indicating multiple prehistoric dispersals from a single Asian centre. These two dispersal pathways converged in the Americas where chickens were introduced both by Polynesians and later by Europeans. The results of this study also highlight the inappropriate application of the small stretch of D-loop, traditionally amplified for use in phylogenetic studies, to understanding discrete episodes of chicken translocation in the past. The results of this study lead to the proposal of four hypotheses which will require further scrutiny and rigorous future testing. PMID:22848352

  1. Bona fide colour: DNA prediction of human eye and hair colour from ancient and contemporary skeletal remains

    NARCIS (Netherlands)

    J. Draus-Barini (Jolanta); S. Walsh (Susan); E. Pośpiech (Ewelina); T. Kupiec (Tomasz); H. Głab (Henryk); W. Branicki (Wojciech); M.H. Kayser (Manfred)

    2013-01-01

    textabstractBackground: DNA analysis of ancient skeletal remains is invaluable in evolutionary biology for exploring the history of species, including humans. Contemporary human bones and teeth, however, are relevant in forensic DNA analyses that deal with the identification of perpetrators, missing

  2. Ancient DNA Study: A Powerful Molecular Biology Tool for Tracing the Past

    Institute of Scientific and Technical Information of China (English)

    Wang Li

    2001-01-01

    In the present study, the author has completed an analysis of the DNA sequence of the human bones unearthed from ancient tombs in the vicinity of Linzi City, in the central part of Shandong Province,making clear the distribution and genetic types of human populations on the Shandong Peninsula during different historical periods and their affinity with modern man. The author also introduces an on-going project to examine the bones of Shang Dynasty (1600-1046 BC) people excavated from Yinxu, located in today′s Anyang City, in northern Henan Province, which will reconstruct the population structure,migration patterns and cultural features of the dynasty.

  3. Ancient DNA reveals traces of Iberian Neolithic and Bronze Age lineages in modern Iberian horses.

    Science.gov (United States)

    Lira, Jaime; Linderholm, Anna; Olaria, Carmen; Brandström Durling, Mikael; Gilbert, M Thomas P; Ellegren, Hans; Willerslev, Eske; Lidén, Kerstin; Arsuaga, Juan Luis; Götherström, Anders

    2010-01-01

    Multiple geographical regions have been proposed for the domestication of Equus caballus. It has been suggested, based on zooarchaeological and genetic analyses that wild horses from the Iberian Peninsula were involved in the process, and the overrepresentation of mitochondrial D1 cluster in modern Iberian horses supports this suggestion. To test this hypothesis, we analysed mitochondrial DNA from 22 ancient Iberian horse remains belonging to the Neolithic, the Bronze Age and the Middle Ages, against previously published sequences. Only the medieval Iberian sequence appeared in the D1 group. Neolithic and Bronze Age sequences grouped in other clusters, one of which (Lusitano group C) is exclusively represented by modern horses of Iberian origin. Moreover, Bronze Age Iberian sequences displayed the lowest nucleotide diversity values when compared with modern horses, ancient wild horses and other ancient domesticates using nonparametric bootstrapping analyses. We conclude that the excessive clustering of Bronze Age horses in the Lusitano group C, the observed nucleotide diversity and the local continuity from wild Neolithic Iberian to modern Iberian horses, could be explained by the use of local wild mares during an early Iberian domestication or restocking event, whereas the D1 group probably was introduced into Iberia in later historical times.

  4. Ancient DNA from lake sediments: Bridging the gap between paleoecology and genetics

    Directory of Open Access Journals (Sweden)

    Lumibao Candice Y

    2011-01-01

    Full Text Available Abstract Background Quaternary plant ecology in much of the world has historically relied on morphological identification of macro- and microfossils from sediments of small freshwater lakes. Here, we report new protocols that reliably yield DNA sequence data from Holocene plant macrofossils and bulk lake sediment used to infer ecological change. This will allow changes in census populations, estimated from fossils and associated sediment, to be directly associated with population genetic changes. Results We successfully sequenced DNA from 64 samples (out of 126 comprised of bulk sediment and seeds, leaf fragments, budscales, and samaras extracted from Holocene lake sediments in the western Great Lakes region of North America. Overall, DNA yields were low. However, we were able to reliably amplify samples with as few as 10 copies of a short cpDNA fragment with little detectable PCR inhibition. Our success rate was highest for sediments Conclusions An ability to extract ancient DNA from Holocene sediments potentially allows exciting new insights into the genetic consequences of long-term environmental change. The low DNA copy numbers we found in fossil material and the discovery of multiple sequence variants from single macrofossil extractions highlight the need for careful experimental and laboratory protocols. Further application of these protocols should lead to better understanding of the ecological and evolutionary consequences of environmental change.

  5. Blocking human contaminant DNA during PCR allows amplification of rare mammal species from sedimentary ancient DNA

    DEFF Research Database (Denmark)

    Boessenkool, Sanne; Epp, Laura S.; Haile, James Seymour

    2012-01-01

    Analyses of degraded DNA are typically hampered by contamination, especially when employing universal primers such as commonly used in environmental DNA studies. In addition to false-positive results, the amplification of contaminant DNA may cause false-negative results because of competition, or...

  6. Use of ancient sedimentary DNA as a novel conservation tool for high-altitude tropical biodiversity.

    Science.gov (United States)

    Boessenkool, Sanne; McGlynn, Gayle; Epp, Laura S; Taylor, David; Pimentel, Manuel; Gizaw, Abel; Nemomissa, Sileshi; Brochmann, Christian; Popp, Magnus

    2014-04-01

    Conservation of biodiversity may in the future increasingly depend upon the availability of scientific information to set suitable restoration targets. In traditional paleoecology, sediment-based pollen provides a means to define preanthropogenic impact conditions, but problems in establishing the exact provenance and ecologically meaningful levels of taxonomic resolution of the evidence are limiting. We explored the extent to which the use of sedimentary ancient DNA (sedaDNA) may complement pollen data in reconstructing past alpine environments in the tropics. We constructed a record of afro-alpine plants retrieved from DNA preserved in sediment cores from 2 volcanic crater sites in the Albertine Rift, eastern Africa. The record extended well beyond the onset of substantial anthropogenic effects on tropical mountains. To ensure high-quality taxonomic inference from the sedaDNA sequences, we built an extensive DNA reference library covering the majority of the afro-alpine flora, by sequencing DNA from taxonomically verified specimens. Comparisons with pollen records from the same sediment cores showed that plant diversity recovered with sedaDNA improved vegetation reconstructions based on pollen records by revealing both additional taxa and providing increased taxonomic resolution. Furthermore, combining the 2 measures assisted in distinguishing vegetation change at different geographic scales; sedaDNA almost exclusively reflects local vegetation, whereas pollen can potentially originate from a wide area that in highlands in particular can span several ecozones. Our results suggest that sedaDNA may provide information on restoration targets and the nature and magnitude of human-induced environmental changes, including in high conservation priority, biodiversity hotspots, where understanding of preanthropogenic impact (or reference) conditions is highly limited.

  7. Complete mitochondrial genome of wild aurochs (Bos primigenius) reconstructed from ancient DNA.

    Science.gov (United States)

    Zeyland, J; Wolko, L; Bocianowski, J; Szalata, M; Słomski, R; Dzieduszycki, A M; Ryba, M; Przystałowska, H; Lipiński, D

    2013-01-01

    Extinct aurochs (Bos primigenius), accepted as the ancestor of domestic cattle, was one of the largest wild animals inhabiting Europe, Asia and North Africa. The gradual process of aurochs extinction finished in Poland in 1627, were the last recorded aurochs, a female, died. Some aspects of cattle domestication history and the distribution of aurochs genetic material among modern cattle breeds still remain unclear. Analyses of ancient DNA (aDNA) from bone sample deliver new genetic information about extinct wild aurochs as well as modern cattle phylogeny. DNA was extracted from a fragment of aurochs fossil bone found in the Pisz Forest, Poland. The sample was radiocarbon-dated to about 1500 yBP. The aDNA was used for Whole Genome Amplification in order to form a DNA bank. Auroch mitochondrial DNA sequences were amplified using sets of 41 primers overlapping the whole mtDNA, cloned and sequenced. The sequence of the whole mitochondrial genome was reconstructed and deposed in GenBank [GenBank:JQ437479]. Based on the phylogenetic analyses of the Bovine mitochondrial genomes, a phylogenetic tree was created. As expected, the tree clearly shows that the mtDNA sequence of the analyzed PWA (Polish Wild Aurochs) individual belongs to haplogroup P. In the course of the comparative mtDNA analysis we identified 30 nucleotide marker positions for haplogroup P and nine unique PWA differences compared to the two remaining haplotype P representatives. Our analysis provides the next step to the reconstruction of the demographic history of this extinct but still exciting species.

  8. Establishing the validity of domestication genes using DNA from ancient chickens.

    Science.gov (United States)

    Girdland Flink, Linus; Allen, Richard; Barnett, Ross; Malmström, Helena; Peters, Joris; Eriksson, Jonas; Andersson, Leif; Dobney, Keith; Larson, Greger

    2014-04-29

    Modern domestic plants and animals are subject to human-driven selection for desired phenotypic traits and behavior. Large-scale genetic studies of modern domestic populations and their wild relatives have revealed not only the genetic mechanisms underlying specific phenotypic traits, but also allowed for the identification of candidate domestication genes. Our understanding of the importance of these genes during the initial stages of the domestication process traditionally rests on the assumption that robust inferences about the past can be made on the basis of modern genetic datasets. A growing body of evidence from ancient DNA studies, however, has revealed that ancient and even historic populations often bear little resemblance to their modern counterparts. Here, we test the temporal context of selection on specific genetic loci known to differentiate modern domestic chickens from their extant wild ancestors. We extracted DNA from 80 ancient chickens excavated from 12 European archaeological sites, dated from ∼ 280 B.C. to the 18th century A.D. We targeted three unlinked genetic loci: the mitochondrial control region, a gene associated with yellow skin color (β-carotene dioxygenase 2), and a putative domestication gene thought to be linked to photoperiod and reproduction (thyroid-stimulating hormone receptor, TSHR). Our results reveal significant variability in both nuclear genes, suggesting that the commonality of yellow skin in Western breeds and the near fixation of TSHR in all modern chickens took place only in the past 500 y. In addition, mitochondrial variation has increased as a result of recent admixture with exotic breeds. We conclude by emphasizing the perils of inferring the past from modern genetic data alone.

  9. Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus.

    Science.gov (United States)

    Weyrich, Laura S; Duchene, Sebastian; Soubrier, Julien; Arriola, Luis; Llamas, Bastien; Breen, James; Morris, Alan G; Alt, Kurt W; Caramelli, David; Dresely, Veit; Farrell, Milly; Farrer, Andrew G; Francken, Michael; Gully, Neville; Haak, Wolfgang; Hardy, Karen; Harvati, Katerina; Held, Petra; Holmes, Edward C; Kaidonis, John; Lalueza-Fox, Carles; de la Rasilla, Marco; Rosas, Antonio; Semal, Patrick; Soltysiak, Arkadiusz; Townsend, Grant; Usai, Donatella; Wahl, Joachim; Huson, Daniel H; Dobney, Keith; Cooper, Alan

    2017-03-08

    Recent genomic data have revealed multiple interactions between Neanderthals and modern humans, but there is currently little genetic evidence regarding Neanderthal behaviour, diet, or disease. Here we describe the shotgun-sequencing of ancient DNA from five specimens of Neanderthal calcified dental plaque (calculus) and the characterization of regional differences in Neanderthal ecology. At Spy cave, Belgium, Neanderthal diet was heavily meat based and included woolly rhinoceros and wild sheep (mouflon), characteristic of a steppe environment. In contrast, no meat was detected in the diet of Neanderthals from El Sidrón cave, Spain, and dietary components of mushrooms, pine nuts, and moss reflected forest gathering. Differences in diet were also linked to an overall shift in the oral bacterial community (microbiota) and suggested that meat consumption contributed to substantial variation within Neanderthal microbiota. Evidence for self-medication was detected in an El Sidrón Neanderthal with a dental abscess and a chronic gastrointestinal pathogen (Enterocytozoon bieneusi). Metagenomic data from this individual also contained a nearly complete genome of the archaeal commensal Methanobrevibacter oralis (10.2× depth of coverage)-the oldest draft microbial genome generated to date, at around 48,000 years old. DNA preserved within dental calculus represents a notable source of information about the behaviour and health of ancient hominin specimens, as well as a unique system that is useful for the study of long-term microbial evolution.

  10. Toward a new history and geography of human genes informed by ancient DNA.

    Science.gov (United States)

    Pickrell, Joseph K; Reich, David

    2014-09-01

    Genetic information contains a record of the history of our species, and technological advances have transformed our ability to access this record. Many studies have used genome-wide data from populations today to learn about the peopling of the globe and subsequent adaptation to local conditions. Implicit in this research is the assumption that the geographic locations of people today are informative about the geographic locations of their ancestors in the distant past. However, it is now clear that long-range migration, admixture, and population replacement subsequent to the initial out-of-Africa expansion have altered the genetic structure of most of the world's human populations. In light of this we argue that it is time to critically reevaluate current models of the peopling of the globe, as well as the importance of natural selection in determining the geographic distribution of phenotypes. We specifically highlight the transformative potential of ancient DNA. By accessing the genetic make-up of populations living at archaeologically known times and places, ancient DNA makes it possible to directly track migrations and responses to natural selection.

  11. Ancient DNA analysis - An established technique in charting the evolution of tuberculosis and leprosy.

    Science.gov (United States)

    Donoghue, Helen D; Spigelman, Mark; O'Grady, Justin; Szikossy, Ildikó; Pap, Ildikó; Lee, Oona Y-C; Wu, Houdini H T; Besra, Gurdyal S; Minnikin, David E

    2015-06-01

    Many tuberculosis and leprosy infections are latent or paucibacillary, suggesting a long time-scale for host and pathogen co-existence. Palaeopathology enables recognition of archaeological cases and PCR detects pathogen ancient DNA (aDNA). Mycobacterium tuberculosis and Mycobacterium leprae cell wall lipids are more stable than aDNA and restrict permeability, thereby possibly aiding long-term persistence of pathogen aDNA. Amplification of aDNA, using specific PCR primers designed for short fragments and linked to fluorescent probes, gives good results, especially when designed to target multi-copy loci. Such studies have confirmed tuberculosis and leprosy, including co-infections. Many tuberculosis cases have non-specific or no visible skeletal pathology, consistent with the natural history of this disease. M. tuberculosis and M. leprae are obligate parasites, closely associated with their human host following recent clonal distribution. Therefore genotyping based on single nucleotide polymorphisms (SNPs) can indicate their origins, spread and phylogeny. Knowledge of extant genetic lineages at particular times in past human populations can be obtained from well-preserved specimens where molecular typing is possible, using deletion analysis, microsatellite analysis and whole genome sequencing. Such studies have identified non-bovine tuberculosis from a Pleistocene bison from 17,500 years BP, human tuberculosis from 9000 years ago and leprosy from over 2000 years ago.

  12. DNA analysis of ancient dogs of the Americas: identifying possible founding haplotypes and reconstructing population histories.

    Science.gov (United States)

    Witt, Kelsey E; Judd, Kathleen; Kitchen, Andrew; Grier, Colin; Kohler, Timothy A; Ortman, Scott G; Kemp, Brian M; Malhi, Ripan S

    2015-02-01

    As dogs have traveled with humans to every continent, they can potentially serve as an excellent proxy when studying human migration history. Past genetic studies into the origins of Native American dogs have used portions of the hypervariable region (HVR) of mitochondrial DNA (mtDNA) to indicate that prior to European contact the dogs of Native Americans originated in Eurasia. In this study, we summarize past DNA studies of both humans and dogs to discuss their population histories in the Americas. We then sequenced a portion of the mtDNA HVR of 42 pre-Columbian dogs from three sites located in Illinois, coastal British Columbia, and Colorado, and identify four novel dog mtDNA haplotypes. Next, we analyzed a dataset comprised of all available ancient dog sequences from the Americas to infer the pre-Columbian population history of dogs in the Americas. Interestingly, we found low levels of genetic diversity for some populations consistent with the possibility of deliberate breeding practices. Furthermore, we identified multiple putative founding haplotypes in addition to dog haplotypes that closely resemble those of wolves, suggesting admixture with North American wolves or perhaps a second domestication of canids in the Americas. Notably, initial effective population size estimates suggest at least 1000 female dogs likely existed in the Americas at the time of the first known canid burial, and that population size increased gradually over time before stabilizing roughly 1200 years before present.

  13. Ancient microbes from halite fluid inclusions: optimized surface sterilization and DNA extraction.

    Directory of Open Access Journals (Sweden)

    Krithivasan Sankaranarayanan

    Full Text Available Fluid inclusions in evaporite minerals (halite, gypsum, etc. potentially preserve genetic records of microbial diversity and changing environmental conditions of Earth's hydrosphere for nearly one billion years. Here we describe a robust protocol for surface sterilization and retrieval of DNA from fluid inclusions in halite that, unlike previously published methods, guarantees removal of potentially contaminating surface-bound DNA. The protocol involves microscopic visualization of cell structures, deliberate surface contamination followed by surface sterilization with acid and bleach washes, and DNA extraction using Amicon centrifugal filters. Methods were verified on halite crystals of four different ages from Saline Valley, California (modern, 36 ka, 64 ka, and 150 ka, with retrieval of algal and archaeal DNA, and characterization of the algal community using ITS1 sequences. The protocol we developed opens up new avenues for study of ancient microbial ecosystems in fluid inclusions, understanding microbial evolution across geological time, and investigating the antiquity of life on earth and other parts of the solar system.

  14. New ancient DNA sequences suggest high genetic diversity for the woolly mammoth (Mammuthus primigenius )

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Partial DNA sequences of cytochrome b gene (mtDNA) were successfully retrieved from Late Pleistocene fossil bone of Mammuthus primigenius collected from the Xiguitu County (Yakeshi), Inner Mongolia Autonomous Region and from Zhaodong, Harbin of Heilongjiang Province in northern China. Two ancient DNA fragments ( 109 bp and 124 bp) were authenticated by reproducible experiments in two different laboratories and by phylogenetic analysis with other Elephantidae taxa. Phylogenetic analysis using these sequences and published data in either separate or combined datasets indicate unstable relationship among the woolly mammoth and the two living elephants, Elephas and Loxodonta. In addition to the short sequences used to attempt the long independent evolution of Elephantidae terminal taxa, we suggest that a high intra-specific diversity existed in Mammuthus primigenius crossing both spatial and temporal ranges, resulting in a complex and divergent genetic background for DNA sequences so far recovered. The high genetic diversity in the extinct woolly mammoth can explain the apparent instability of Elephantidae taxa on the molecular phylogenetic trees and can reconcile the apparent paradox regarding the unresolved Elephantidae trichotomy.

  15. Fungal palaeodiversity revealed using high-throughput metabarcoding of ancient DNA from arctic permafrost.

    Science.gov (United States)

    Bellemain, Eva; Davey, Marie L; Kauserud, Håvard; Epp, Laura S; Boessenkool, Sanne; Coissac, Eric; Geml, Jozsef; Edwards, Mary; Willerslev, Eske; Gussarova, Galina; Taberlet, Pierre; Haile, James; Brochmann, Christian

    2013-04-01

    The taxonomic and ecological diversity of ancient fungal communities was assessed by combining next generation sequencing and metabarcoding of DNA preserved in permafrost. Twenty-six sediment samples dated 16 000-32 000 radiocarbon years old from two localities in Siberia were analysed for fungal ITS. We detected 75 fungal OTUs from 21 orders representing three phyla, although rarefaction analyses suggested that the full diversity was not recovered despite generating an average of 6677 ± 3811 (mean ± SD) sequences per sample and that preservation bias likely has considerable effect on the recovered DNA. Most OTUs (75.4%) represented ascomycetes. Due to insufficient sequencing depth, DNA degradation and putative preservation biases in our samples, the recovered taxa probably do not represent the complete historic fungal community, and it is difficult to determine whether the fungal communities varied geographically or experienced a composition shift within the period of 16 000-32 000 bp. However, annotation of OTUs to functional ecological groups provided a wealth of information on the historic communities. About one-third of the OTUs are presumed plant-associates (pathogens, saprotrophs and endophytes) typical of graminoid- and forb-rich habitats. We also detected putative insect pathogens, coprophiles and keratinophiles likely associated with ancient insect and herbivore faunas. The detection of putative insect pathogens, mycoparasites, aquatic fungi and endophytes broadens our previous knowledge of the diversity of fungi present in Beringian palaeoecosystems. A large group of putatively psychrophilic/psychrotolerant fungi was also detected, most likely representing a modern, metabolically active fungal community.

  16. Ancient mtDNA genetic variants modulate mtDNA transcription and replication.

    Directory of Open Access Journals (Sweden)

    Sarit Suissa

    2009-05-01

    Full Text Available Although the functional consequences of mitochondrial DNA (mtDNA genetic backgrounds (haplotypes, haplogroups have been demonstrated by both disease association studies and cell culture experiments, it is not clear which of the mutations within the haplogroup carry functional implications and which are "evolutionary silent hitchhikers". We set forth to study the functionality of haplogroup-defining mutations within the mtDNA transcription/replication regulatory region by in vitro transcription, hypothesizing that haplogroup-defining mutations occurring within regulatory motifs of mtDNA could affect these processes. We thus screened >2500 complete human mtDNAs representing all major populations worldwide for natural variation in experimentally established protein binding sites and regulatory regions comprising a total of 241 bp in each mtDNA. Our screen revealed 77/241 sites showing point mutations that could be divided into non-fixed (57/77, 74% and haplogroup/sub-haplogroup-defining changes (i.e., population fixed changes, 20/77, 26%. The variant defining Caucasian haplogroup J (C295T increased the binding of TFAM (Electro Mobility Shift Assay and the capacity of in vitro L-strand transcription, especially of a shorter transcript that maps immediately upstream of conserved sequence block 1 (CSB1, a region associated with RNA priming of mtDNA replication. Consistent with this finding, cybrids (i.e., cells sharing the same nuclear genetic background but differing in their mtDNA backgrounds harboring haplogroup J mtDNA had a >2 fold increase in mtDNA copy number, as compared to cybrids containing haplogroup H, with no apparent differences in steady state levels of mtDNA-encoded transcripts. Hence, a haplogroup J regulatory region mutation affects mtDNA replication or stability, which may partially account for the phenotypic impact of this haplogroup. Our analysis thus demonstrates, for the first time, the functional impact of particular mtDNA

  17. A comparative study of ancient sedimentary DNA, pollen and macrofossils from permafrost sediments of northern Siberia reveals long-term vegetational stability

    DEFF Research Database (Denmark)

    Jørgensen, Tina; Haile, James Seymour; Möller, Per

    2012-01-01

    Although ancient DNA from sediments (sedaDNA) has been used to investigate past ecosystems, the approach has never been directly compared with the traditional methods of pollen and macrofossil analysis. We conducted a comparative survey of 18 ancient permafrost samples spanning the Late Pleistoce...

  18. Patterns of East Asian pig domestication, migration, and turnover revealed by modern and ancient DNA.

    Science.gov (United States)

    Larson, Greger; Liu, Ranran; Zhao, Xingbo; Yuan, Jing; Fuller, Dorian; Barton, Loukas; Dobney, Keith; Fan, Qipeng; Gu, Zhiliang; Liu, Xiao-Hui; Luo, Yunbing; Lv, Peng; Andersson, Leif; Li, Ning

    2010-04-27

    The establishment of agricultural economies based upon domestic animals began independently in many parts of the world and led to both increases in human population size and the migration of people carrying domestic plants and animals. The precise circumstances of the earliest phases of these events remain mysterious given their antiquity and the fact that subsequent waves of migrants have often replaced the first. Through the use of more than 1,500 modern (including 151 previously uncharacterized specimens) and 18 ancient (representing six East Asian archeological sites) pig (Sus scrofa) DNA sequences sampled across East Asia, we provide evidence for the long-term genetic continuity between modern and ancient Chinese domestic pigs. Although the Chinese case for independent pig domestication is supported by both genetic and archaeological evidence, we discuss five additional (and possibly) independent domestications of indigenous wild boar populations: one in India, three in peninsular Southeast Asia, and one off the coast of Taiwan. Collectively, we refer to these instances as "cryptic domestication," given the current lack of corroborating archaeological evidence. In addition, we demonstrate the existence of numerous populations of genetically distinct and widespread wild boar populations that have not contributed maternal genetic material to modern domestic stocks. The overall findings provide the most complete picture yet of pig evolution and domestication in East Asia, and generate testable hypotheses regarding the development and spread of early farmers in the Far East.

  19. Ancient DNA from Nubian and Somali wild ass provides insights into donkey ancestry and domestication.

    Science.gov (United States)

    Kimura, Birgitta; Marshall, Fiona B; Chen, Shanyuan; Rosenbom, Sónia; Moehlman, Patricia D; Tuross, Noreen; Sabin, Richard C; Peters, Joris; Barich, Barbara; Yohannes, Hagos; Kebede, Fanuel; Teclai, Redae; Beja-Pereira, Albano; Mulligan, Connie J

    2011-01-07

    Genetic data from extant donkeys (Equus asinus) have revealed two distinct mitochondrial DNA haplogroups, suggestive of two separate domestication events in northeast Africa about 5000 years ago. Without distinct phylogeographic structure in domestic donkey haplogroups and with little information on the genetic makeup of the ancestral African wild ass, however, it has been difficult to identify wild ancestors and geographical origins for the domestic mitochondrial clades. Our analysis of ancient archaeological and historic museum samples provides the first genetic information on the historic Nubian wild ass (Equus africanus africanus), Somali wild ass (Equus africanus somaliensis) and ancient donkey. The results demonstrate that the Nubian wild ass was an ancestor of the first donkey haplogroup. In contrast, the Somali wild ass has considerable mitochondrial divergence from the Nubian wild ass and domestic donkeys. These findings resolve the long-standing issue of the role of the Nubian wild ass in the domestication of the donkey, but raise new questions regarding the second ancestor for the donkey. Our results illustrate the complexity of animal domestication, and have conservation implications for critically endangered Nubian and Somali wild ass.

  20. A conditional likelihood is required to estimate the selection coefficient in ancient DNA

    CERN Document Server

    Valleriani, Angelo

    2016-01-01

    Time-series of allele frequencies are a useful and unique set of data to determine the strength of natural selection on the background of genetic drift. Technically, the selection coefficient is estimated by means of a likelihood function built under the hypothesis that the available trajectory spans a sufficiently large portion of the fitness landscape. Especially for ancient DNA, however, often only one single such trajectories is available and the coverage of the fitness landscape is very limited. In fact, one single trajectory is more representative of a process conditioned both in the initial and in the final condition than of a process free to end anywhere. Based on the Moran model of population genetics, here we show how to build a likelihood function for the selection coefficient that takes the statistical peculiarity of single trajectories into account. We show that this conditional likelihood delivers a precise estimate of the selection coefficient also when allele frequencies are close to fixation ...

  1. Radiocarbon-dating and ancient DNA reveal rapid replacement of extinct prehistoric penguins

    Science.gov (United States)

    Rawlence, Nicolas J.; Perry, George L. W.; Smith, Ian W. G.; Scofield, R. Paul; Tennyson, Alan J. D.; Matisoo-Smith, Elizabeth A.; Boessenkool, Sanne; Austin, Jeremy J.; Waters, Jonathan M.

    2015-03-01

    Prehistoric faunal extinctions dramatically reshaped biological assemblages around the world. However, the timing of such biotic shifts is often obscured by the fragmentary nature and limited temporal resolution of fossil records. We use radiocarbon-dating and ancient-DNA analysis of prehistoric (ca A.D. 1450-1834) Megadyptes penguin specimens to assess the time-frame of biological turnover in coastal New Zealand following human settlement. These data suggest that the final extirpation of the endemic Megadyptes waitaha, and subsequent replacement by the previously sub-Antarctic-limited Megadyptes antipodes, likely occurred within a narrow temporal window (e.g. a century or less). This transition represents one of the most rapid prehistoric faunal turnover events documented, and is likely linked to human demographic and cultural transitions during the 15th Century. Our results suggest that anthropogenic forces can trigger rapid biogeographic shifts.

  2. Paging through history: parchment as a reservoir of ancient DNA for next generation sequencing.

    Science.gov (United States)

    Teasdale, M D; van Doorn, N L; Fiddyment, S; Webb, C C; O'Connor, T; Hofreiter, M; Collins, M J; Bradley, D G

    2015-01-19

    Parchment represents an invaluable cultural reservoir. Retrieving an additional layer of information from these abundant, dated livestock-skins via the use of ancient DNA (aDNA) sequencing has been mooted by a number of researchers. However, prior PCR-based work has indicated that this may be challenged by cross-individual and cross-species contamination, perhaps from the bulk parchment preparation process. Here we apply next generation sequencing to two parchments of seventeenth and eighteenth century northern English provenance. Following alignment to the published sheep, goat, cow and human genomes, it is clear that the only genome displaying substantial unique homology is sheep and this species identification is confirmed by collagen peptide mass spectrometry. Only 4% of sequence reads align preferentially to a different species indicating low contamination across species. Moreover, mitochondrial DNA sequences suggest an upper bound of contamination at 5%. Over 45% of reads aligned to the sheep genome, and even this limited sequencing exercise yield 9 and 7% of each sampled sheep genome post filtering, allowing the mapping of genetic affinity to modern British sheep breeds. We conclude that parchment represents an excellent substrate for genomic analyses of historical livestock.

  3. Joseon funerary texts tested using ancient DNA analysis of a Korean mummy.

    Science.gov (United States)

    Oh, Chang Seok; Koh, Bou-Ja; Yoo, Dong Soo; Park, Jun Bum; Min, So Ri; Kim, Yi-Suk; Lee, Sang Sup; Ge, Jianye; Seo, Seung Bum; Shin, Dong Hoon

    2015-06-01

    In Korea, ancient DNA (aDNA) analysis has been applied to investigations into the genetic affiliations of mummies found in Joseon Dynasty tombs (1392-1910 CE), becoming now indispensable tool for researches studying human remains from archaeological sites. In the course of our recent examinations on a Korean mummy of Joseon Dynasty, we discovered many teeth contained in a pouch. And in fact, the historical literature on the topic of Joseon funerals contain general accounts of pouches in which an individual's lost teeth were collected over the course of a lifetime and, after death, placed in the coffin with the body. To test the veracity of the historical texts, the present study undertook aDNA analyses and compared the results between specifically questioned (Q) samples (teeth) and known (K) samples (brain and bone) from the mummy to ensure that they came from the same individual. Although the Q-K comparison of autosomal short tandem repeat results did not show full concordance due to allelic drop-outs in some loci, our statistical calculation indicated that the teeth in the pouch are highly likely those of the mummy. Additionally, Q-K comparison of mitochondrial DNA sequence results showed 100% matches between samples. There results, in short, could not gainsay the conjecture that the teeth samples originated from the person buried in the tomb; and if so, he must have kept his teeth for a long time after their loss. As the application of aDNA analysis to Korean mummy studies develops, there will be other opportunities to test historical documents, particularly those referring to funerary rites.

  4. Population dynamics and genetic changes of Picea abies in the South Carpathians revealed by pollen and ancient DNA analyses

    Directory of Open Access Journals (Sweden)

    Braun Mihály

    2011-03-01

    Full Text Available Abstract Background Studies on allele length polymorphism designate several glacial refugia for Norway spruce (Picea abies in the South Carpathian Mountains, but infer only limited expansion from these refugia after the last glaciation. To better understand the genetic dynamics of a South Carpathian spruce lineage, we compared ancient DNA from 10,700 and 11,000-year-old spruce pollen and macrofossils retrieved from Holocene lake sediment in the Retezat Mountains with DNA extracted from extant material from the same site. We used eight primer pairs that amplified short and variable regions of the spruce cpDNA. In addition, from the same lake sediment we obtained a 15,000-years-long pollen accumulation rate (PAR record for spruce that helped us to infer changes in population size at this site. Results We obtained successful amplifications for Norway spruce from 17 out of 462 pollen grains tested, while the macrofossil material provided 22 DNA sequences. Two fossil sequences were found to be unique to the ancient material. Population genetic statistics showed higher genetic diversity in the ancient individuals compared to the extant ones. Similarly, statistically significant Ks and Kst values showed a considerable level of differentiation between extant and ancient populations at the same loci. Lateglacial and Holocene PAR values suggested that population size of the ancient population was small, in the range of 1/10 or 1/5 of the extant population. PAR analysis also detected two periods of rapid population growths (from ca. 11,100 and 3900 calibrated years before present (cal yr BP and three bottlenecks (around 9180, 7200 and 2200 cal yr BP, likely triggered by climatic change and human impact. Conclusion Our results suggest that the paternal lineages observed today in the Retezat Mountains persisted at this site at least since the early Holocene. Combination of the results from the genetic and the PAR analyses furthermore suggests that the higher

  5. Of Amoebae and Men: Extracellular DNA Traps as an Ancient Cell-Intrinsic Defense Mechanism

    Science.gov (United States)

    Zhang, Xuezhi; Soldati, Thierry

    2016-01-01

    Since the discovery of the formation of DNA-based extracellular traps (ETs) by neutrophils as an innate immune defense mechanism (1), hundreds of articles describe the involvement of ETs in physiological and pathological human and animal conditions [reviewed in Ref. (2), and the previous Frontiers Research Topic on NETosis: http://www.frontiersin.org/books/NETosis_At_the_Intersection_of_Cell_Biology_Microbiology_and_Immunology/195]. Interestingly, a few reports reveal that ETs can be formed by immune cells of more ancient organisms, as far back as the common ancestor of vertebrates and invertebrates (3). Recently, we reported that the Sentinel cells of the multicellular slug of the social amoeba Dictyostelium discoideum also produce ETs to trap and kill slug-invading bacteria [see Box 1; and Figure 1 Ref. (4)]. This is a strong evidence that DNA-based cell-intrinsic defense mechanisms emerged much earlier than thought, about 1.3 billion years ago. Amazingly, using extrusion of DNA as a weapon to capture and kill uningestable microbes has its rationale. During the emergence of multicellularity, a primitive innate immune system developed in the form of a dedicated set of specialized phagocytic cells. This professionalization of immunity allowed the evolution of sophisticated defense mechanisms including the sacrifice of a small set of cells by a mechanism related to NETosis. This altruistic behavior likely emerged in steps, starting from the release of “dispensable” mitochondrial DNA by D. discoideum Sentinel cells. Grounded in this realization, one can anticipate that in the near future, many more examples of the invention and fine-tuning of ETs by early metazoan ancestors will be identified. Consequently, it can be expected that this more complete picture of the evolution of ETs will impact our views of the involvement and pathologies linked to ETs in human and animals. PMID:27458458

  6. The genetic impact of Aztec imperialism: ancient mitochondrial DNA evidence from Xaltocan, Mexico.

    Science.gov (United States)

    Mata-Míguez, Jaime; Overholtzer, Lisa; Rodríguez-Alegría, Enrique; Kemp, Brian M; Bolnick, Deborah A

    2012-12-01

    In AD 1428, the city-states of Tenochtitlan, Texcoco, and Tlacopan formed the Triple Alliance, laying the foundations of the Aztec empire. Although it is well documented that the Aztecs annexed numerous polities in the Basin of Mexico over the following years, the demographic consequences of this expansion remain unclear. At the city-state capital of Xaltocan, 16th century documents suggest that the site's conquest and subsequent incorporation into the Aztec empire led to a replacement of the original Otomí population, whereas archaeological evidence suggests that some of the original population may have remained at the town under Aztec rule. To help address questions about Xaltocan's demographic history during this period, we analyzed ancient DNA from 25 individuals recovered from three houses rebuilt over time and occupied between AD 1240 and 1521. These individuals were divided into two temporal groups that predate and postdate the site's conquest. We determined the mitochondrial DNA haplogroup of each individual and identified haplotypes based on 372 base pair sequences of first hypervariable region. Our results indicate that the residents of these houses before and after the Aztec conquest have distinct haplotypes that are not closely related, and the mitochondrial compositions of the temporal groups are statistically different. Altogether, these results suggest that the matrilines present in the households were replaced following the Aztec conquest. This study therefore indicates that the Aztec expansion may have been associated with significant demographic and genetic changes within Xaltocan.

  7. Ancient DNA reveals a migration of the ancient Di-qiang populations into Xinjiang as early as the early Bronze Age.

    Science.gov (United States)

    Gao, Shi-Zhu; Zhang, Ye; Wei, Dong; Li, Hong-Jie; Zhao, Yong-Bin; Cui, Yin-Qiu; Zhou, Hui

    2015-05-01

    Xinjiang is at the crossroads between East and West Eurasia, and it harbors a relatively complex genetic history. In order to better understand the population movements and interactions in this region, mitochondrial and Y chromosome analyses on 40 ancient human remains from the Tianshanbeilu site in eastern Xinjiang were performed. Twenty-nine samples were successfully assigned to specific mtDNA haplogroups, including the west Eurasian maternal lineages of U and W and the east Eurasian maternal lineages of A, C, D, F, G, Z, M7, and M10. In the male samples, two Y chromosome haplogroups, C* and N1 (xN1a, N1c), were successfully assigned. Our mitochondrial and Y-chromosomal DNA analyses combined with the archaeological studies revealed that the Di-qiang populations from the Hexi Corridor had migrated to eastern Xinjiang and admixed with the Eurasian steppe populations in the early Bronze Age.

  8. Use DNA to learn from the past: how modern and ancient DNA studies may help reveal the past and predict the future distribution of species

    Science.gov (United States)

    Edwards, M. E.; Alsos, I. G.; Sjögren, P.; Coissac, E.; Gielly, L.; Yoccoz, N.; Føreid, M. K.; Taberlet, P.

    2015-12-01

    Knowledge of how climate change affected species distribution in the past may help us predict the effect of ongoing environmental changes. We explore how the use of modern (AFLP fingerprinting techniques) and ancient DNA (metabarcoding P6 loop of chloroplast DNA) help to reveal past distribution of vascular plant species, dispersal processes, and effect of species traits. Based on studies of modern DNA combined with species distribution models, we show the dispersal routes and barriers to dispersal throughout the circumarctic/circumboreal region, likely dispersal vectors, the cost of dispersal in term of loss of genetic diversity, and how these relates to species traits, dispersal distance, and size of colonized region. We also estimate the expected future distribution and loss of genetic diversity and show how this relates to life form and adaptations to dispersal. To gain more knowledge on time lags in past range change events, we rely on palaeorecords. Current data on past distribution are limited by the taxonomic and time resolution of macrofossil and pollen records. We show how this may be improved by studying ancient DNA of lake sediments. DNA of lake sediments recorded about half of the flora surrounding the lake. Compared to macrofossil, the taxonomic resolution is similar but the detection rate is considerable improved. By taking into account main determinants of founder effect, dispersal vectors, and dispersal lags, we may improve our ability to forecast effects of climate change, whereas more studies on ancient DNA may provide us with knowledge on distribution time lags.

  9. Pulling out the 1%: whole-genome capture for the targeted enrichment of ancient DNA sequencing libraries.

    Science.gov (United States)

    Carpenter, Meredith L; Buenrostro, Jason D; Valdiosera, Cristina; Schroeder, Hannes; Allentoft, Morten E; Sikora, Martin; Rasmussen, Morten; Gravel, Simon; Guillén, Sonia; Nekhrizov, Georgi; Leshtakov, Krasimir; Dimitrova, Diana; Theodossiev, Nikola; Pettener, Davide; Luiselli, Donata; Sandoval, Karla; Moreno-Estrada, Andrés; Li, Yingrui; Wang, Jun; Gilbert, M Thomas P; Willerslev, Eske; Greenleaf, William J; Bustamante, Carlos D

    2013-11-07

    Most ancient specimens contain very low levels of endogenous DNA, precluding the shotgun sequencing of many interesting samples because of cost. Ancient DNA (aDNA) libraries often contain libraries. By using biotinylated RNA baits transcribed from genomic DNA libraries, we are able to capture DNA fragments from across the human genome. We demonstrate this method on libraries created from four Iron Age and Bronze Age human teeth from Bulgaria, as well as bone samples from seven Peruvian mummies and a Bronze Age hair sample from Denmark. Prior to capture, shotgun sequencing of these libraries yielded an average of 1.2% of reads mapping to the human genome (including duplicates). After capture, this fraction increased substantially, with up to 59% of reads mapped to human and enrichment ranging from 6- to 159-fold. Furthermore, we maintained coverage of the majority of regions sequenced in the precapture library. Intersection with the 1000 Genomes Project reference panel yielded an average of 50,723 SNPs (range 3,062-147,243) for the postcapture libraries sequenced with 1 million reads, compared with 13,280 SNPs (range 217-73,266) for the precapture libraries, increasing resolution in population genetic analyses. Our whole-genome capture approach makes it less costly to sequence aDNA from specimens containing very low levels of endogenous DNA, enabling the analysis of larger numbers of samples.

  10. A conditional likelihood is required to estimate the selection coefficient in ancient DNA.

    Science.gov (United States)

    Valleriani, Angelo

    2016-08-16

    Time-series of allele frequencies are a useful and unique set of data to determine the strength of natural selection on the background of genetic drift. Technically, the selection coefficient is estimated by means of a likelihood function built under the hypothesis that the available trajectory spans a sufficiently large portion of the fitness landscape. Especially for ancient DNA, however, often only one single such trajectories is available and the coverage of the fitness landscape is very limited. In fact, one single trajectory is more representative of a process conditioned both in the initial and in the final condition than of a process free to visit the available fitness landscape. Based on two models of population genetics, here we show how to build a likelihood function for the selection coefficient that takes the statistical peculiarity of single trajectories into account. We show that this conditional likelihood delivers a precise estimate of the selection coefficient also when allele frequencies are close to fixation whereas the unconditioned likelihood fails. Finally, we discuss the fact that the traditional, unconditioned likelihood always delivers an answer, which is often unfalsifiable and appears reasonable also when it is not correct.

  11. A conditional likelihood is required to estimate the selection coefficient in ancient DNA

    Science.gov (United States)

    Valleriani, Angelo

    2016-08-01

    Time-series of allele frequencies are a useful and unique set of data to determine the strength of natural selection on the background of genetic drift. Technically, the selection coefficient is estimated by means of a likelihood function built under the hypothesis that the available trajectory spans a sufficiently large portion of the fitness landscape. Especially for ancient DNA, however, often only one single such trajectories is available and the coverage of the fitness landscape is very limited. In fact, one single trajectory is more representative of a process conditioned both in the initial and in the final condition than of a process free to visit the available fitness landscape. Based on two models of population genetics, here we show how to build a likelihood function for the selection coefficient that takes the statistical peculiarity of single trajectories into account. We show that this conditional likelihood delivers a precise estimate of the selection coefficient also when allele frequencies are close to fixation whereas the unconditioned likelihood fails. Finally, we discuss the fact that the traditional, unconditioned likelihood always delivers an answer, which is often unfalsifiable and appears reasonable also when it is not correct.

  12. Use of pollen and ancient DNA as conservation baselines for offshore islands in New Zealand.

    Science.gov (United States)

    Wilmshurst, Janet M; Moar, Neville T; Wood, Jamie R; Bellingham, Peter J; Findlater, Amy M; Robinson, James J; Stone, Clive

    2014-02-01

    Islands play a key role globally in the conservation of endemic species. Many island reserves have been highly modified since human colonization, and their restoration and management usually occur without knowledge of their prehuman state. However, conservation paleoecology is increasingly being recognized as a tool that can help to inform both restoration and conservation of island reserves by providing prehuman vegetation baselines. Many of New Zealand's mammal-free offshore islands are foci for biological diversity conservation and, like many islands in the Polynesian region, were deforested following initial human settlement. Therefore, their current restoration, replanting, and management are guided either by historic vegetation descriptions or the occurrence of species on forested islands. We analyzed pollen and ancient DNA in soil cores from an offshore island in northern New Zealand. The result was a 2000-year record of vegetation change that began >1200 years before human settlement and spanned 550 years of human occupation and 180 years of forest succession since human occupation ceased. Between prehuman and contemporary forests there was nearly a complete species turnover including the extirpation of a dominant conifer and a palm tree. The podocarp-dominated forests were replaced by a native but novel angiosperm-dominated forest. There is no modern analog of the prehuman forests on any northern New Zealand island, and those islands that are forested are dominated by angiosperms which are assumed to be climax forests. The pollen and DNA evidence for conifer- and palm-rich forests in the prehuman era challenge this climax forest assumption. Prehuman vegetation records can thus help to inform future restoration of degraded offshore islands by informing the likely rate and direction of successional change; helping to determine whether natural rates of succession are preferable to more costly replanting programs; and providing past species lists if

  13. Investigating kinship of Neolithic post-LBK human remains from Krusza Zamkowa, Poland using ancient DNA.

    Science.gov (United States)

    Juras, Anna; Chyleński, Maciej; Krenz-Niedbała, Marta; Malmström, Helena; Ehler, Edvard; Pospieszny, Łukasz; Łukasik, Sylwia; Bednarczyk, Józef; Piontek, Janusz; Jakobsson, Mattias; Dabert, Miroslawa

    2017-01-01

    We applied an interdisciplinary approach to investigate kinship patterns and funerary practices during the middle Neolithic. Genetic studies, radiocarbon dating, and taphonomic analyses were used to examine two grave clusters from Krusza Zamkowa, Poland. To reconstruct kinship and determine biological sex, we extracted DNA from bones and teeth, analyzed mitochondrial genomes and nuclear SNPs using the HID-Ion AmpliSeq™ Identity panel generated on Illumina and Ion Torrent platforms, respectively. We further dated the material (AMS (14)C) and to exclude aquatic radiocarbon reservoir effects, measures of carbon and nitrogen stable isotopes for diet reconstruction were used. We found distinct mitochondrial genomes belonging to haplogroups U5b2a1a, K1c and H3d in the first grave cluster, and excluded maternal kin patterns among the three analyzed individuals. In the second grave cluster one individual belonged to K1a4. However, we could not affiliate the second individual to a certain haplogroup due to the fragmented state of the mitochondrial genome. Although the individuals from the second grave cluster differ at position 6643, we believe that more data is needed to fully resolve this issue. We retrieved between 26 and 77 autosomal SNPs from three of the individuals. Based on kinship estimations, taking into account the allelic dropout distribution, we could not exclude first degree kin relation between the two individuals from the second grave cluster. We could, however, exclude a first degree kinship between these two individuals and an individual from the first grave cluster. Presumably, not only biological kinship, but also social relations played an important role in the funerary practice during this time period. We further conclude that the HID-Ion AmpliSeq™ Identity Panel may prove useful for first degree kin relation studies for samples with good DNA preservation, and that mitochondrial genome capture enrichment is a powerful tool for excluding direct

  14. Ancient genomics

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Allentoft, Morten Erik; Avila Arcos, Maria del Carmen

    2015-01-01

    by increasing the number of sequence reads to billions effectively means that contamination issues that have haunted aDNA research for decades, particularly in human studies, can now be efficiently and confidently quantified. At present, whole genomes have been sequenced from ancient anatomically modern humans......, archaic hominins, ancient pathogens and megafaunal species. Those have revealed important functional and phenotypic information, as well as unexpected adaptation, migration and admixture patterns. As such, the field of aDNA has entered the new era of genomics and has provided valuable information when...

  15. Geochemical Analyses of Macrophytes (Potamogeton sp.) and ancient DNA from Lake Karakul, Tajikistan

    Science.gov (United States)

    Heinecke, Liv; Epp, Laura S.; Mischke, Steffen; Reschke, Maria; Stoof-Leichsenring, Kathleen; Rajabov, Ilhomjon; Herzschuh, Ulrike

    2016-04-01

    Mountain ecosystems are very sensitive towards changes in moisture and temperature and therefore most likely to be affected by climate change. To be able to get a closer insight into the alpine system of the Pamir Mountains, a 11.25 m long core was retrieved from the eastern basin of Lake Karakul (3,929 m asl), Tajikistan, in 2012. In order to gain insights into changes in the paleo-productivity of Lake Karakul over the last 29 cal kyrs BP, we investigate temporal gradients of elemental content (TOC, TN) and stable isotopes (δ13C, δ15N) of macrophyte remains (Potamogeton sp.) and plant communities obtained from ancient sedimentary DNA along the core. For the geochemical analyses we make use of the ability of submerged macrophytes, such as Potamogeton, to use HCO3- for photosynthesis in times of CO2 shortage and implement our results in a transfer function for paleo-productivity inferences. No data are available from 20 to 7 cal kyrs BP as no macrophyte remains are preserved, indicating unfavourable conditions for plant growth at the coring site or poor preservation conditions during this time. Biogeochemical analyses show significant variations from core base until approx. 20 cal kyrs BP with TOCPotamogeton 25-45 %, TNPotamogeton 0.5 % - 1.5 %, δ13CPotamogeton below -9 ‰ and δ15NPotamogeton of below 3.5 ‰ suggesting a cooler climate and reflecting the last glacial maximum. Sediments in the upper 4.5 m (approx. 6.7 cal kyrs BP) are rich in macrophyte remains. TOCPotamogeton and TNPotamogeton values from this part of the core are higher, and an enrichment of heavier isotopes with δ13CPotamogeton up to -7 ‰ and δ15NPotamogeton up to 6 ‰ indicating a higher productivity within the lake due to more favourable conditions for macrophyte growths on the lake floor. We assume shifts towards a warmer climate and changes in lake level as the dominating causes. Ancient sedimentary DNA was extracted from selected sediment slices and a metabarcoding approach (using

  16. DNA typing of ancient parasite eggs from environmental samples identifies human and animal worm infections in viking-age settlement

    DEFF Research Database (Denmark)

    Søe, Martin Jensen; Nejsum, Peter; Fredensborg, Brian Lund;

    2015-01-01

    . The identification of T. trichiura eggs indicates that human fecal material is present and, hence, that the Ascaris sp. haplotype 07 was most likely a human variant in Viking-age Denmark. The location of the F. hepatica finding suggests that sheep or cattle are the most likely hosts. Further, we sequenced...... selecting genetic markers, PCR amplification and sequencing of ancient DNA (aDNA) isolates resulted in identification of: the human whipworm, Trichuris trichiura, using SSUrRNA sequence homology; Ascaris sp. with 100% homology to cox1 haplotype 07; and Fasciola hepatica using ITS1 sequence homology...

  17. Novel DNA Extraction Method Unveiled the Ancient Hot Deep Biosphere Concealed in Terrestrial Sedimentary Rocks

    Science.gov (United States)

    Kouduka, M.; Suko, T.; Okuzawa, K.; Fukuda, A.; Nanba, K.; Yamamoto, M.; Sakata, S.; Ito, K.; Suzuki, Y.

    2009-12-01

    thermophilic bacteria and the transformation of silica minerals in the deep subsurface. As intensive erosion is unlikely around the drilling site, a short period of hydrothermal activities rather than long-term burial at great depth caused high temperature conditions, which might explain the lack of maturity in hydrocarbon. A novel DNA-based approach coupled mineralogical and organic geochemical analyses has the potential to reconstruct ancient biogeochemical processes mediated in the deep subsurface as well as geothermal history. This study was supported by grants from the Nuclear and Industrial Safety Agency (NISA) and Japan Nuclear Energy Safety Organization (JNES).

  18. Ancient DNA analysis of the extinct North American flat-headed peccary (Platygonus compressus).

    Science.gov (United States)

    Perry, Tahlia; van Loenen, Ayla L; Heiniger, Holly; Lee, Carol; Gongora, Jaime; Cooper, Alan; Mitchell, Kieren J

    2017-03-28

    The geographical range of extant peccaries extends from the southwestern United States through Central America and into northern Argentina. However, from the Miocene until the Pleistocene now-extinct peccary species inhabited the entirety of North America. Relationships among the living and extinct species have long been contentious. Similarly, how and when peccaries moved from North to South America is unclear. The North American flat-headed peccary (Platygonus compressus) became extinct at the end of the Pleistocene and is one of the most abundant subfossil taxa found in North America, yet despite this extensive fossil record its phylogenetic position has not been resolved. This study is the first to present DNA data from the flat-headed peccary and full mitochondrial genome sequences of all the extant peccary species. We performed a molecular phylogenetic analysis to determine the relationships among ancient and extant peccary species. Our results suggested that the flat-headed peccary is sister-taxon to a clade comprising the extant peccary species. Divergence date estimates from our molecular dating analyses suggest that if extant peccary diversification occurred in South America then their common ancestor must have dispersed from North America to South America well before the establishment of the Isthmus of Panama. We also investigated the genetic diversity of the flat-headed peccary by performing a preliminary population study on specimens from Sheriden Cave, Ohio. Flat-headed peccaries from Sheriden Cave appear to be genetically diverse and show no signature of population decline prior to extinction. Including additional extinct Pleistocene peccary species in future phylogenetic analyses will further clarify peccary evolution.

  19. Detection of the A189G mtDNA heteroplasmic mutation in relation to age in modern and ancient bones.

    Science.gov (United States)

    Lacan, Marie; Thèves, Catherine; Amory, Sylvain; Keyser, Christine; Crubézy, Eric; Salles, Jean-Pierre; Ludes, Bertrand; Telmon, Norbert

    2009-03-01

    The aim of this study was to demonstrate the presence of the A189G age-related point mutation on DNA extracted from bone. For this, a peptide nucleic acid (PNA)/DNA sequencing method which can determine an age threshold for the appearance of the mutation was used. Initially, work was done in muscle tissue in order to evaluate the sensitivity of the technique and afterwards in bone samples from the same individuals. This method was also applied to ancient bones from six well-preserved skeletal remains. The mutation was invariably found in muscle, and at a rate of up to 20% in individuals over 60 years old. In modern bones, the mutation was detected in individuals aged 38 years old or more, at a rate of up to 1%, but its occurrence was not systematic (only four out of ten of the individuals over 50 years old carried the heteroplasmy). For ancient bones, the mutation was also found in the oldest individuals according to osteologic markers. The study of this type of age-related mutation and a more complete understanding of its manifestation has potentially useful applications. Combined with traditional age markers, it could improve identification accuracy in forensic cases or in anthropological studies of ancient populations.

  20. Ancient DNA from European early neolithic farmers reveals their near eastern affinities.

    Directory of Open Access Journals (Sweden)

    Wolfgang Haak

    Full Text Available In Europe, the Neolithic transition (8,000-4,000 B.C. from hunting and gathering to agricultural communities was one of the most important demographic events since the initial peopling of Europe by anatomically modern humans in the Upper Paleolithic (40,000 B.C.. However, the nature and speed of this transition is a matter of continuing scientific debate in archaeology, anthropology, and human population genetics. To date, inferences about the genetic make up of past populations have mostly been drawn from studies of modern-day Eurasian populations, but increasingly ancient DNA studies offer a direct view of the genetic past. We genetically characterized a population of the earliest farming culture in Central Europe, the Linear Pottery Culture (LBK; 5,500-4,900 calibrated B.C. and used comprehensive phylogeographic and population genetic analyses to locate its origins within the broader Eurasian region, and to trace potential dispersal routes into Europe. We cloned and sequenced the mitochondrial hypervariable segment I and designed two powerful SNP multiplex PCR systems to generate new mitochondrial and Y-chromosomal data from 21 individuals from a complete LBK graveyard at Derenburg Meerenstieg II in Germany. These results considerably extend the available genetic dataset for the LBK (n = 42 and permit the first detailed genetic analysis of the earliest Neolithic culture in Central Europe (5,500-4,900 calibrated B.C.. We characterized the Neolithic mitochondrial DNA sequence diversity and geographical affinities of the early farmers using a large database of extant Western Eurasian populations (n = 23,394 and a wide range of population genetic analyses including shared haplotype analyses, principal component analyses, multidimensional scaling, geographic mapping of genetic distances, and Bayesian Serial Simcoal analyses. The results reveal that the LBK population shared an affinity with the modern-day Near East and Anatolia, supporting

  1. Ancient DNA analyses of museum specimens from selected Presbytis (primate: Colobinae) based on partial Cyt b sequences

    Science.gov (United States)

    Aifat, N. R.; Yaakop, S.; Md-Zain, B. M.

    2016-11-01

    The IUCN Red List of Threatened Species has categorized Malaysian primates from being data deficient to critically endanger. Thus, ancient DNA analyses hold great potential to understand phylogeny, phylogeography and population history of extinct and extant species. Museum samples are one of the alternatives to provide important sources of biological materials for a large proportion of ancient DNA studies. In this study, a total of six museum skin samples from species Presbytis hosei (4 samples) and Presbytis frontata (2 samples), aged between 43 and 124 years old were extracted to obtain the DNA. Extraction was done by using QIAGEN QIAamp DNA Investigator Kit and the ability of this kit to extract museum skin samples was tested by amplification of partial Cyt b sequence using species-specific designed primer. Two primer pairs were designed specifically for P. hosei and P. frontata, respectively. These primer pairs proved to be efficient in amplifying 200bp of the targeted species in the optimized PCR conditions. The performance of the sequences were tested to determine genetic distance of genus Presbytis in Malaysia. From the analyses, P. hosei is closely related to P. chrysomelas and P. frontata with the value of 0.095 and 0.106, respectively. Cyt b gave a clear data in determining relationships among Bornean species. Thus, with the optimized condition, museum specimens can be used for molecular systematic studies of the Malaysian primates.

  2. Unravelling the complexity of domestication: a case study using morphometrics and ancient DNA analyses of archaeological pigs from Romania.

    Science.gov (United States)

    Evin, Allowen; Flink, Linus Girdland; Bălăşescu, Adrian; Popovici, Dragomir; Andreescu, Radian; Bailey, Douglas; Mirea, Pavel; Lazăr, Cătălin; Boroneanţ, Adina; Bonsall, Clive; Vidarsdottir, Una Strand; Brehard, Stéphanie; Tresset, Anne; Cucchi, Thomas; Larson, Greger; Dobney, Keith

    2015-01-19

    Current evidence suggests that pigs were first domesticated in Eastern Anatolia during the ninth millennium cal BC before dispersing into Europe with Early Neolithic farmers from the beginning of the seventh millennium. Recent ancient DNA (aDNA) research also indicates the incorporation of European wild boar into domestic stock during the Neolithization process. In order to establish the timing of the arrival of domestic pigs into Europe, and to test hypotheses regarding the role European wild boar played in the domestication process, we combined a geometric morphometric analysis (allowing us to combine tooth size and shape) of 449 Romanian ancient teeth with aDNA analysis. Our results firstly substantiate claims that the first domestic pigs in Romania possessed the same mtDNA signatures found in Neolithic pigs in west and central Anatolia. Second, we identified a significant proportion of individuals with large molars whose tooth shape matched that of archaeological (likely) domestic pigs. These large 'domestic shape' specimens were present from the outset of the Romanian Neolithic (6100-5500 cal BC) through to later prehistory, suggesting a long history of admixture between introduced domestic pigs and local wild boar. Finally, we confirmed a turnover in mitochondrial lineages found in domestic pigs, possibly coincident with human migration into Anatolia and the Levant that occurred in later prehistory.

  3. Histological analysis and ancient DNA amplification of human bone remains found in caius iulius polybius house in pompeii.

    Science.gov (United States)

    Cipollaro, M; Di Bernado, G; Forte, A; Galano, G; De Masi, L; Galderisi, U; Guarino, F M; Angelini, F; Cascino, A

    1999-09-01

    Thirteen skeletons found in the Caius Iulius Polybius house, which has been the object of intensive study since its discovery in Pompeii 250 years ago, have provided an opportunity to study either bone diagenesis by histological investigation or ancient DNA by polymerase chain reaction analysis. DNA analysis was done by amplifying both X- and Y-chromosomes amelogenin loci and Y-specific alphoid repeat locus. The von Willebrand factor (vWF) microsatellite locus on chromosome 12 was also analyzed for personal identification in two individuals showing alleles with 10/11 and 12/12 TCTA repeats, respectively. Technical problems were the scarcity of DNA content from osteocytes, DNA molecule fragmentation, microbial contamination which change bone structure, contaminating human DNA which results from mishandling, and frequent presence of Taq DNA polymerase inhibiting molecules like polyphenols and heavy metals. The results suggest that the remains contain endogenous human DNA that can be amplified and analyzed. The amplifiability of DNA corresponds to the bone preservation and dynamics of the burial conditions subsequent to the 79 A.D. eruption.

  4. Ancient genomics

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Allentoft, Morten Erik; Avila Arcos, Maria del Carmen;

    2015-01-01

    , archaic hominins, ancient pathogens and megafaunal species. Those have revealed important functional and phenotypic information, as well as unexpected adaptation, migration and admixture patterns. As such, the field of aDNA has entered the new era of genomics and has provided valuable information when...

  5. Pre-Columbian population dynamics in coastal southern Peru: A diachronic investigation of mtDNA patterns in the Palpa region by ancient DNA analysis.

    Science.gov (United States)

    Fehren-Schmitz, Lars; Reindel, Markus; Cagigao, Elsa Tomasto; Hummel, Susanne; Herrmann, Bernd

    2010-02-01

    Alternative models have been proposed to explain the formation and decline of the south Peruvian Nasca culture, ranging from migration or invasion to autochthonous development and ecological crisis. To reveal to what extent population dynamic processes accounted for cultural development in the Nasca mainland, or were influenced by them, we analyzed ancient mitochondrial DNA of 218 individuals, originating from chronologically successive archaeological sites in the Palpa region, the Paracas Peninsula, and the Andean highlands in southern Peru. The sampling strategy allowed a diachronic analysis in a time frame from approximately 800 BC to 800 AD. Mitochondrial coding region polymorphisms were successfully analyzed and replicated for 130 individuals and control region sequences (np 16021-16408) for 104 individuals to determine Native American mitochondrial DNA haplogroups and haplotypes. The results were compared with ancient and contemporary Peruvian populations to reveal genetic relations of the archaeological samples. Frequency data and statistics show clear proximity of the Nasca populations to the populations of the preceding Paracas culture from Palpa and the Peninsula, and suggest, along with archaeological data, that the Nasca culture developed autochthonously in the Rio Grande drainage. Furthermore, the influence of changes in socioeconomic complexity in the Palpa area on the genetic diversity of the local population could be observed. In all, a strong genetic affinity between pre-Columbian coastal populations from southern Peru could be determined, together with a significant differentiation from ancient highland and all present-day Peruvian reference populations, best shown in the differential distribution of mitochondrial haplogroups.

  6. Pig Domestication and Human-Mediated Dispersal in Western Eurasia Revealed through Ancient DNA and Geometric Morphometrics

    Science.gov (United States)

    Ottoni, Claudio; Girdland Flink, Linus; Evin, Allowen; Geörg, Christina; De Cupere, Bea; Van Neer, Wim; Bartosiewicz, László; Linderholm, Anna; Barnett, Ross; Peters, Joris; Decorte, Ronny; Waelkens, Marc; Vanderheyden, Nancy; Ricaut, François-Xavier; Çakırlar, Canan; Çevik, Özlem; Hoelzel, A. Rus; Mashkour, Marjan; Mohaseb Karimlu, Azadeh Fatemeh; Sheikhi Seno, Shiva; Daujat, Julie; Brock, Fiona; Pinhasi, Ron; Hongo, Hitomi; Perez-Enciso, Miguel; Rasmussen, Morten; Frantz, Laurent; Megens, Hendrik-Jan; Crooijmans, Richard; Groenen, Martien; Arbuckle, Benjamin; Benecke, Nobert; Strand Vidarsdottir, Una; Burger, Joachim; Cucchi, Thomas; Dobney, Keith; Larson, Greger

    2013-01-01

    Zooarcheological evidence suggests that pigs were domesticated in Southwest Asia ∼8,500 BC. They then spread across the Middle and Near East and westward into Europe alongside early agriculturalists. European pigs were either domesticated independently or more likely appeared so as a result of admixture between introduced pigs and European wild boar. As a result, European wild boar mtDNA lineages replaced Near Eastern/Anatolian mtDNA signatures in Europe and subsequently replaced indigenous domestic pig lineages in Anatolia. The specific details of these processes, however, remain unknown. To address questions related to early pig domestication, dispersal, and turnover in the Near East, we analyzed ancient mitochondrial DNA and dental geometric morphometric variation in 393 ancient pig specimens representing 48 archeological sites (from the Pre-Pottery Neolithic to the Medieval period) from Armenia, Cyprus, Georgia, Iran, Syria, and Turkey. Our results reveal the first genetic signatures of early domestic pigs in the Near Eastern Neolithic core zone. We also demonstrate that these early pigs differed genetically from those in western Anatolia that were introduced to Europe during the Neolithic expansion. In addition, we present a significantly more refined chronology for the introduction of European domestic pigs into Asia Minor that took place during the Bronze Age, at least 900 years earlier than previously detected. By the 5th century AD, European signatures completely replaced the endemic lineages possibly coinciding with the widespread demographic and societal changes that occurred during the Anatolian Bronze and Iron Ages. PMID:23180578

  7. Pig domestication and human-mediated dispersal in western Eurasia revealed through ancient DNA and geometric morphometrics.

    Science.gov (United States)

    Ottoni, Claudio; Flink, Linus Girdland; Evin, Allowen; Geörg, Christina; De Cupere, Bea; Van Neer, Wim; Bartosiewicz, László; Linderholm, Anna; Barnett, Ross; Peters, Joris; Decorte, Ronny; Waelkens, Marc; Vanderheyden, Nancy; Ricaut, François-Xavier; Cakirlar, Canan; Cevik, Ozlem; Hoelzel, A Rus; Mashkour, Marjan; Karimlu, Azadeh Fatemeh Mohaseb; Seno, Shiva Sheikhi; Daujat, Julie; Brock, Fiona; Pinhasi, Ron; Hongo, Hitomi; Perez-Enciso, Miguel; Rasmussen, Morten; Frantz, Laurent; Megens, Hendrik-Jan; Crooijmans, Richard; Groenen, Martien; Arbuckle, Benjamin; Benecke, Nobert; Vidarsdottir, Una Strand; Burger, Joachim; Cucchi, Thomas; Dobney, Keith; Larson, Greger

    2013-04-01

    Zooarcheological evidence suggests that pigs were domesticated in Southwest Asia ~8,500 BC. They then spread across the Middle and Near East and westward into Europe alongside early agriculturalists. European pigs were either domesticated independently or more likely appeared so as a result of admixture between introduced pigs and European wild boar. As a result, European wild boar mtDNA lineages replaced Near Eastern/Anatolian mtDNA signatures in Europe and subsequently replaced indigenous domestic pig lineages in Anatolia. The specific details of these processes, however, remain unknown. To address questions related to early pig domestication, dispersal, and turnover in the Near East, we analyzed ancient mitochondrial DNA and dental geometric morphometric variation in 393 ancient pig specimens representing 48 archeological sites (from the Pre-Pottery Neolithic to the Medieval period) from Armenia, Cyprus, Georgia, Iran, Syria, and Turkey. Our results reveal the first genetic signatures of early domestic pigs in the Near Eastern Neolithic core zone. We also demonstrate that these early pigs differed genetically from those in western Anatolia that were introduced to Europe during the Neolithic expansion. In addition, we present a significantly more refined chronology for the introduction of European domestic pigs into Asia Minor that took place during the Bronze Age, at least 900 years earlier than previously detected. By the 5th century AD, European signatures completely replaced the endemic lineages possibly coinciding with the widespread demographic and societal changes that occurred during the Anatolian Bronze and Iron Ages.

  8. Ancient DNA reveals prehistoric gene-flow from siberia in the complex human population history of North East Europe.

    Science.gov (United States)

    Der Sarkissian, Clio; Balanovsky, Oleg; Brandt, Guido; Khartanovich, Valery; Buzhilova, Alexandra; Koshel, Sergey; Zaporozhchenko, Valery; Gronenborn, Detlef; Moiseyev, Vyacheslav; Kolpakov, Eugen; Shumkin, Vladimir; Alt, Kurt W; Balanovska, Elena; Cooper, Alan; Haak, Wolfgang

    2013-01-01

    North East Europe harbors a high diversity of cultures and languages, suggesting a complex genetic history. Archaeological, anthropological, and genetic research has revealed a series of influences from Western and Eastern Eurasia in the past. While genetic data from modern-day populations is commonly used to make inferences about their origins and past migrations, ancient DNA provides a powerful test of such hypotheses by giving a snapshot of the past genetic diversity. In order to better understand the dynamics that have shaped the gene pool of North East Europeans, we generated and analyzed 34 mitochondrial genotypes from the skeletal remains of three archaeological sites in northwest Russia. These sites were dated to the Mesolithic and the Early Metal Age (7,500 and 3,500 uncalibrated years Before Present). We applied a suite of population genetic analyses (principal component analysis, genetic distance mapping, haplotype sharing analyses) and compared past demographic models through coalescent simulations using Bayesian Serial SimCoal and Approximate Bayesian Computation. Comparisons of genetic data from ancient and modern-day populations revealed significant changes in the mitochondrial makeup of North East Europeans through time. Mesolithic foragers showed high frequencies and diversity of haplogroups U (U2e, U4, U5a), a pattern observed previously in European hunter-gatherers from Iberia to Scandinavia. In contrast, the presence of mitochondrial DNA haplogroups C, D, and Z in Early Metal Age individuals suggested discontinuity with Mesolithic hunter-gatherers and genetic influx from central/eastern Siberia. We identified remarkable genetic dissimilarities between prehistoric and modern-day North East Europeans/Saami, which suggests an important role of post-Mesolithic migrations from Western Europe and subsequent population replacement/extinctions. This work demonstrates how ancient DNA can improve our understanding of human population movements across

  9. Ancient DNA reveals prehistoric gene-flow from siberia in the complex human population history of North East Europe.

    Directory of Open Access Journals (Sweden)

    Clio Der Sarkissian

    Full Text Available North East Europe harbors a high diversity of cultures and languages, suggesting a complex genetic history. Archaeological, anthropological, and genetic research has revealed a series of influences from Western and Eastern Eurasia in the past. While genetic data from modern-day populations is commonly used to make inferences about their origins and past migrations, ancient DNA provides a powerful test of such hypotheses by giving a snapshot of the past genetic diversity. In order to better understand the dynamics that have shaped the gene pool of North East Europeans, we generated and analyzed 34 mitochondrial genotypes from the skeletal remains of three archaeological sites in northwest Russia. These sites were dated to the Mesolithic and the Early Metal Age (7,500 and 3,500 uncalibrated years Before Present. We applied a suite of population genetic analyses (principal component analysis, genetic distance mapping, haplotype sharing analyses and compared past demographic models through coalescent simulations using Bayesian Serial SimCoal and Approximate Bayesian Computation. Comparisons of genetic data from ancient and modern-day populations revealed significant changes in the mitochondrial makeup of North East Europeans through time. Mesolithic foragers showed high frequencies and diversity of haplogroups U (U2e, U4, U5a, a pattern observed previously in European hunter-gatherers from Iberia to Scandinavia. In contrast, the presence of mitochondrial DNA haplogroups C, D, and Z in Early Metal Age individuals suggested discontinuity with Mesolithic hunter-gatherers and genetic influx from central/eastern Siberia. We identified remarkable genetic dissimilarities between prehistoric and modern-day North East Europeans/Saami, which suggests an important role of post-Mesolithic migrations from Western Europe and subsequent population replacement/extinctions. This work demonstrates how ancient DNA can improve our understanding of human population

  10. Mitochondrial haplogroup C in ancient mitochondrial DNA from Ukraine extends the presence of East Eurasian genetic lineages in Neolithic Central and Eastern Europe.

    Science.gov (United States)

    Nikitin, Alexey G; Newton, Jeremy R; Potekhina, Inna D

    2012-09-01

    Recent studies of ancient mitochondrial DNA (mtDNA) lineages have revealed the presence of East Eurasian mtDNA haplogroups in the Central European Neolithic. Here we report the finding of East Eurasian lineages in ancient mtDNA from two Neolithic cemeteries of the North Pontic Region (NPR) in Ukraine. In our study, comprehensive haplotyping information was obtained for 7 out of 18 specimens. Although the majority of identified mtDNA haplogroups belonged to the traditional West Eurasian lineages of H and U, three specimens were determined to belong to the lineages of mtDNA haplogroup C. This find extends the presence of East Eurasian lineages in Neolithic Europe from the Carpathian Mountains to the northern shores of the Black Sea and provides the first genetic account of Neolithic mtDNA lineages from the NPR.

  11. Evidence Supporting the Uptake and Genomic Incorporation of Environmental DNA in the “Ancient Asexual” Bdelloid Rotifer Philodina roseola

    Directory of Open Access Journals (Sweden)

    Olaf R. P. Bininda-Emonds

    2016-09-01

    Full Text Available Increasing evidence suggests that bdelloid rotifers regularly undergo horizontal gene transfer, apparently as a surrogate mechanism of genetic exchange in the absence of true sexual reproduction, in part because of their ability to withstand desiccation. We provide empirical support for this latter hypothesis using the bdelloid Philodina roseola, which we demonstrate to readily internalize environmental DNA in contrast to a representative monogonont rotifer (Brachionus rubens, which, like other monogononts, is facultative sexual and cannot withstand desiccation. In addition, environmental DNA that was more similar to the host DNA was retained more often and for a longer period of time. Indirect evidence (increased variance in the reproductive output of the untreated F1 generation suggests that environmental DNA can be incorporated into the genome during desiccation and is thus heritable. Our observed fitness effects agree with sexual theory and also occurred when the animals were desiccated in groups (thereby acting as DNA donors, but not individually, indicating the mechanism could occur in nature. Thus, although DNA uptake and its genomic incorporation appears proximally related to anhydrobiosis in bdelloids, it might also facilitate accidental genetic exchange with closely related taxa, thereby maintaining higher levels of genetic diversity than is otherwise expected for this group of “ancient asexuals”.

  12. Genetic diversity loss in a biodiversity hotspot: ancient DNA quantifies genetic decline and former connectivity in a critically endangered marsupial.

    Science.gov (United States)

    Pacioni, Carlo; Hunt, Helen; Allentoft, Morten E; Vaughan, Timothy G; Wayne, Adrian F; Baynes, Alexander; Haouchar, Dalal; Dortch, Joe; Bunce, Michael

    2015-12-01

    The extent of genetic diversity loss and former connectivity between fragmented populations are often unknown factors when studying endangered species. While genetic techniques are commonly applied in extant populations to assess temporal and spatial demographic changes, it is no substitute for directly measuring past diversity using ancient DNA (aDNA). We analysed both mitochondrial DNA (mtDNA) and nuclear microsatellite loci from 64 historical fossil and skin samples of the critically endangered Western Australian woylie (Bettongia penicillata ogilbyi), and compared them with 231 (n = 152 for mtDNA) modern samples. In modern woylie populations 15 mitochondrial control region (CR) haplotypes were identified. Interestingly, mtDNA CR data from only 29 historical samples demonstrated 15 previously unknown haplotypes and detected an extinct divergent clade. Through modelling, we estimated the loss of CR mtDNA diversity to be between 46% and 91% and estimated this to have occurred in the past 2000-4000 years in association with a dramatic population decline. In addition, we obtained near-complete 11-loci microsatellite profiles from 21 historical samples. In agreement with the mtDNA data, a number of 'new' microsatellite alleles was only detected in the historical populations despite extensive modern sampling, indicating a nuclear genetic diversity loss >20%. Calculations of genetic diversity (heterozygosity and allelic rarefaction) showed that these were significantly higher in the past and that there was a high degree of gene flow across the woylie's historical range. These findings have an immediate impact on how the extant populations are managed and we recommend the implementation of an assisted migration programme to prevent further loss of genetic diversity. Our study demonstrates the value of integrating aDNA data into current-day conservation strategies.

  13. Low Mitochondrial DNA Diversity in an Ancient Population from China: Insight into Social Organization at the Fujia Site.

    Science.gov (United States)

    Dong, Yu; Li, Chunxiang; Luan, Fengshi; Li, Zhenguang; Li, Hongjie; Cui, Yinqiu; Zhou, Hui; Malhi, Ripan S

    2015-01-01

    To gain insight into the social organization of a population associated with the Dawenkou period, we performed ancient DNA analysis of 18 individuals from human remains from the Fujia site in Shandong Province, China. Directly radiocarbon dated to 4800-4500 cal BP, the Fujia site is assumed to be associated with a transitional phase from matrilineal clans to patrilineal monogamous families. Our results reveal a low mitochondrial DNA diversity from the site and population. Combined with Y chromosome data, the pattern observed at the Fujia site is most consistent with a matrilineal community. The patterns also suggest that the bond of marriage was de-emphasized compared with the bonds of descent at Fujia.

  14. Ancient DNA analyses reveal contrasting phylogeographic patterns amongst kiwi (Apteryx spp. and a recently extinct lineage of spotted kiwi.

    Directory of Open Access Journals (Sweden)

    Lara D Shepherd

    Full Text Available The little spotted kiwi (Apteryx owenii is a flightless ratite formerly found throughout New Zealand but now greatly reduced in distribution. Previous phylogeographic studies of the related brown kiwi (A. mantelli, A. rowi and A. australis, with which little spotted kiwi was once sympatric, revealed extremely high levels of genetic structuring, with mitochondrial DNA haplotypes often restricted to populations. We surveyed genetic variation throughout the present and pre-human range of little spotted kiwi by obtaining mitochondrial DNA sequences from contemporary and ancient samples. Little spotted kiwi and great spotted kiwi (A. haastii formed a monophyletic clade sister to brown kiwi. Ancient samples of little spotted kiwi from the northern North Island, where it is now extinct, formed a lineage that was distinct from remaining little spotted kiwi and great spotted kiwi lineages, potentially indicating unrecognized taxonomic diversity. Overall, little spotted kiwi exhibited much lower levels of genetic diversity and structuring than brown kiwi, particularly through the South Island. Our results also indicate that little spotted kiwi (or at least hybrids involving this species survived on the South Island mainland until more recently than previously thought.

  15. Ancient DNA analyses reveal contrasting phylogeographic patterns amongst kiwi (Apteryx spp.) and a recently extinct lineage of spotted kiwi.

    Science.gov (United States)

    Shepherd, Lara D; Worthy, Trevor H; Tennyson, Alan J D; Scofield, R Paul; Ramstad, Kristina M; Lambert, David M

    2012-01-01

    The little spotted kiwi (Apteryx owenii) is a flightless ratite formerly found throughout New Zealand but now greatly reduced in distribution. Previous phylogeographic studies of the related brown kiwi (A. mantelli, A. rowi and A. australis), with which little spotted kiwi was once sympatric, revealed extremely high levels of genetic structuring, with mitochondrial DNA haplotypes often restricted to populations. We surveyed genetic variation throughout the present and pre-human range of little spotted kiwi by obtaining mitochondrial DNA sequences from contemporary and ancient samples. Little spotted kiwi and great spotted kiwi (A. haastii) formed a monophyletic clade sister to brown kiwi. Ancient samples of little spotted kiwi from the northern North Island, where it is now extinct, formed a lineage that was distinct from remaining little spotted kiwi and great spotted kiwi lineages, potentially indicating unrecognized taxonomic diversity. Overall, little spotted kiwi exhibited much lower levels of genetic diversity and structuring than brown kiwi, particularly through the South Island. Our results also indicate that little spotted kiwi (or at least hybrids involving this species) survived on the South Island mainland until more recently than previously thought.

  16. The examination of ancient DNA: guidelines on precautions, controls, and sample processing

    Directory of Open Access Journals (Sweden)

    Scholz, M.

    2000-06-01

    Full Text Available The young discipline of palaeogenetics has developed into a successful and expectant field of archaeobiological research within the last decade. Palaeogenetic investigation (e.g. PCR, DNA sequencing of ancient specimens is, however, susceptible to falsification by the presence of contamination from more recent times. Contamination which can lead to amplification of non-authentic sequences is known to stem from several sources: (i human biomolecules derived from the persons performing the genetic experiments, perhaps also from the archeologists and other persons who have previously handled the specimens or (ii edaphic DNA sequences derived primarily from bacterial or fungal growth upon the specimen. A third source of contamination can arise from (iii substances used for conservation of specimens. Here we give advice on the correct processing of prehistoric bone samples when further molecular biological examination is required. Along with the demonstration of necessary precautions and working conditions, we further explain how an unequivocal DNA contamination monitoring is performed.

    La paleogenética se ha convertido en los últimos años en una disciplina coronada de éxito que ofrece grandes expectativas para el desarrollo de la investigación arqueobiológica. No obstante, la investigación paleogenética (p. ej: PCR, secuenciación del ADN de especímenes antiguos es susceptible de ser falsificada por la presencia de una contaminación más reciente. Actualmente sabemos que la contaminación que provoca la amplificación de secuencias ''no auténticas" procede de las siguientes fuentes: (i las biomoléculas humanas provienen de la persona que realiza el experimento genético o incluso también del arqueólogo u otras personas que previamente hayan tenido contacto con el espécimen; (ii de secuencias de ADN edáficas derivadas básicamente del crecimiento bacterial o fúngico en el seno del espécimen. La tercera fuente de contaminaci

  17. More on contamination: the use of asymmetric molecular behavior to identify authentic ancient human DNA

    DEFF Research Database (Denmark)

    Malmström, Helena; Svensson, Emma M; Gilbert, M Thomas P;

    2007-01-01

    the reliability of one of the proposed criteria, that of appropriate molecular behavior. Using real-time polymerase chain reaction (PCR) and pyrosequencing, we have quantified the relative levels of authentic aDNA and contaminant human DNA sequences recovered from archaeological dog and cattle remains. In doing....... Furthermore, we find that there is a substantial increase in the relative proportions of authentic DNA to contaminant DNA as the PCR target fragment size is decreased. We therefore conclude that the degradation pattern in aDNA provides a quantifiable difference between authentic aDNA and modern contamination...

  18. Ancient DNA reveals substantial genetic diversity in the California Condor (Gymnogyps californianus) prior to a population bottleneck

    Science.gov (United States)

    D'Elia, Jesse; Haig, Susan M.; Mullins, Thomas D.; Miller, Mark P.

    2016-01-01

    Critically endangered species that have undergone severe population bottlenecks often have little remaining genetic variation, making it difficult to reconstruct population histories to apply in reintroduction and recovery strategies. By using ancient DNA techniques, it is possible to combine genetic evidence from the historical population with contemporary samples to provide a more complete picture of a species' genetic variation across its historical range and through time. Applying this approach, we examined changes in the mitochondrial DNA (mtDNA) control region (526 base pairs) of the endangered California Condor (Gymnogyps californianus). Results showed a >80% reduction in unique haplotypes over the past 2 centuries. We found no spatial sorting of haplotypes in the historical population; the periphery of the range contained haplotypes that were common throughout the historical range. Direct examination of mtDNA from California Condor museum specimens provided a new window into historical population connectivity and genetic diversity showing: (1) a substantial loss of haplotypes, which is consistent with the hypothesis that condors were relatively abundant in the nineteenth century, but declined rapidly as a result of human-caused mortality; and (2) no evidence of historical population segregation, meaning that the available genetic data offer no cause to avoid releasing condors in unoccupied portions of their historical range.

  19. Fragmentation of contaminant and endogenous DNA in ancient samples determined by shotgun sequencing; prospects for human palaeogenomics.

    Directory of Open Access Journals (Sweden)

    Marc García-Garcerà

    Full Text Available BACKGROUND: Despite the successful retrieval of genomes from past remains, the prospects for human palaeogenomics remain unclear because of the difficulty of distinguishing contaminant from endogenous DNA sequences. Previous sequence data generated on high-throughput sequencing platforms indicate that fragmentation of ancient DNA sequences is a characteristic trait primarily arising due to depurination processes that create abasic sites leading to DNA breaks. METHODOLOGY/PRINCIPALS FINDINGS: To investigate whether this pattern is present in ancient remains from a temperate environment, we have 454-FLX pyrosequenced different samples dated between 5,500 and 49,000 years ago: a bone from an extinct goat (Myotragus balearicus that was treated with a depurinating agent (bleach, an Iberian lynx bone not subjected to any treatment, a human Neolithic sample from Barcelona (Spain, and a Neandertal sample from the El Sidrón site (Asturias, Spain. The efficiency of retrieval of endogenous sequences is below 1% in all cases. We have used the non-human samples to identify human sequences (0.35 and 1.4%, respectively, that we positively know are contaminants. CONCLUSIONS: We observed that bleach treatment appears to create a depurination-associated fragmentation pattern in resulting contaminant sequences that is indistinguishable from previously described endogenous sequences. Furthermore, the nucleotide composition pattern observed in 5' and 3' ends of contaminant sequences is much more complex than the flat pattern previously described in some Neandertal contaminants. Although much research on samples with known contaminant histories is needed, our results suggest that endogenous and contaminant sequences cannot be distinguished by the fragmentation pattern alone.

  20. Novel high-resolution characterization of ancient DNA reveals C > U-type base modification events as the sole cause of post mortem miscoding lesions

    Science.gov (United States)

    Brotherton, Paul; Endicott, Phillip; Sanchez, Juan J.; Beaumont, Mark; Barnett, Ross; Austin, Jeremy; Cooper, Alan

    2007-01-01

    Ancient DNA (aDNA) research has long depended on the power of PCR to amplify trace amounts of surviving genetic material from preserved specimens. While PCR permits specific loci to be targeted and amplified, in many ways it can be intrinsically unsuited to damaged and degraded aDNA templates. PCR amplification of aDNA can produce highly-skewed distributions with significant contributions from miscoding lesion damage and non-authentic sequence artefacts. As traditional PCR-based approaches have been unable to fully resolve the molecular nature of aDNA damage over many years, we have developed a novel single primer extension (SPEX)-based approach to generate more accurate sequence information. SPEX targets selected template strands at defined loci and can generate a quantifiable redundancy of coverage; providing new insights into the molecular nature of aDNA damage and fragmentation. SPEX sequence data reveals inherent limitations in both traditional and metagenomic PCR-based approaches to aDNA, which can make current damage analyses and correct genotyping of ancient specimens problematic. In contrast to previous aDNA studies, SPEX provides strong quantitative evidence that C > U-type base modifications are the sole cause of authentic endogenous damage-derived miscoding lesions. This new approach could allow ancient specimens to be genotyped with unprecedented accuracy. PMID:17715147

  1. Novel high-resolution characterization of ancient DNA reveals C > U-type base modification events as the sole cause of post mortem miscoding lesions.

    Science.gov (United States)

    Brotherton, Paul; Endicott, Phillip; Sanchez, Juan J; Beaumont, Mark; Barnett, Ross; Austin, Jeremy; Cooper, Alan

    2007-01-01

    Ancient DNA (aDNA) research has long depended on the power of PCR to amplify trace amounts of surviving genetic material from preserved specimens. While PCR permits specific loci to be targeted and amplified, in many ways it can be intrinsically unsuited to damaged and degraded aDNA templates. PCR amplification of aDNA can produce highly-skewed distributions with significant contributions from miscoding lesion damage and non-authentic sequence artefacts. As traditional PCR-based approaches have been unable to fully resolve the molecular nature of aDNA damage over many years, we have developed a novel single primer extension (SPEX)-based approach to generate more accurate sequence information. SPEX targets selected template strands at defined loci and can generate a quantifiable redundancy of coverage; providing new insights into the molecular nature of aDNA damage and fragmentation. SPEX sequence data reveals inherent limitations in both traditional and metagenomic PCR-based approaches to aDNA, which can make current damage analyses and correct genotyping of ancient specimens problematic. In contrast to previous aDNA studies, SPEX provides strong quantitative evidence that C > U-type base modifications are the sole cause of authentic endogenous damage-derived miscoding lesions. This new approach could allow ancient specimens to be genotyped with unprecedented accuracy.

  2. Ancient DNA analysis of the oldest canid species from the Siberian Arctic and genetic contribution to the domestic dog.

    Directory of Open Access Journals (Sweden)

    Esther J Lee

    Full Text Available Modern Arctic Siberia provides a wealth of resources for archaeological, geological, and paleontological research to investigate the population dynamics of faunal communities from the Pleistocene, particularly as the faunal material coming from permafrost has proven suitable for genetic studies. In order to examine the history of the Canid species in the Siberian Arctic, we carried out genetic analysis of fourteen canid remains from various sites, including the well-documented Upper Paleolithic Yana RHS and Early Holocene Zhokhov Island sites. Estimated age of samples range from as recent as 1,700 years before present (YBP to at least 360,000 YBP for the remains of the extinct wolf, Canis cf. variabilis. In order to examine the genetic affinities of ancient Siberian canids species to the domestic dog and modern wolves, we obtained mitochondrial DNA control region sequences and compared them to published ancient and modern canid sequences. The older canid specimens illustrate affinities with pre-domestic dog/wolf lineages while others appear in the major phylogenetic clades of domestic dogs. Our results suggest a European origin of domestic dog may not be conclusive and illustrates an emerging complexity of genetic contribution of regional wolf breeds to the modern Canis gene pool.

  3. Ancient DNA Analysis Suggests Negligible Impact of the Wari Empire Expansion in Peru's Central Coast during the Middle Horizon.

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    Guido Valverde

    Full Text Available The analysis of ancient human DNA from South America allows the exploration of pre-Columbian population history through time and to directly test hypotheses about cultural and demographic evolution. The Middle Horizon (650-1100 AD represents a major transitional period in the Central Andes, which is associated with the development and expansion of ancient Andean empires such as Wari and Tiwanaku. These empires facilitated a series of interregional interactions and socio-political changes, which likely played an important role in shaping the region's demographic and cultural profiles. We analyzed individuals from three successive pre-Columbian cultures present at the Huaca Pucllana archaeological site in Lima, Peru: Lima (Early Intermediate Period, 500-700 AD, Wari (Middle Horizon, 800-1000 AD and Ychsma (Late Intermediate Period, 1000-1450 AD. We sequenced 34 complete mitochondrial genomes to investigate the potential genetic impact of the Wari Empire in the Central Coast of Peru. The results indicate that genetic diversity shifted only slightly through time, ruling out a complete population discontinuity or replacement driven by the Wari imperialist hegemony, at least in the region around present-day Lima. However, we caution that the very subtle genetic contribution of Wari imperialism at the particular Huaca Pucllana archaeological site might not be representative for the entire Wari territory in the Peruvian Central Coast.

  4. Transcriptional profiling in C. elegans suggests DNA damage dependent apoptosis as an ancient function of the p53 family

    Directory of Open Access Journals (Sweden)

    Rothblatt Jonathan

    2008-07-01

    transcriptional induction of BH3 domain proteins is likely to be an ancient DNA damage response function of the p53 family. Interestingly, although the apoptotic response to DNA damage is regulated through the transcriptional activity of CEP-1, other DNA damage responses do not appear to be regulated on the transcriptional level and do not require the p53 like gene cep-1.

  5. Ancient DNA assessment of tiger salamander population in Yellowstone National Park.

    Science.gov (United States)

    McMenamin, Sarah K; Hadly, Elizabeth A

    2012-01-01

    Recent data indicates that blotched tiger salamanders (Ambystoma tigrinum melanostictum) in northern regions of Yellowstone National Park are declining due to climate-related habitat changes. In this study, we used ancient and modern mitochondrial haplotype diversity to model the effective size of this amphibian population through recent geological time and to assess past responses to climatic changes in the region. Using subfossils collected from a cave in northern Yellowstone, we analyzed >700 base pairs of mitochondrial sequence from 16 samples ranging in age from 100 to 3300 years old and found that all shared an identical haplotype. Although mitochondrial diversity was extremely low within the living population, we still were able to detect geographic subdivision within the local area. Using serial coalescent modelling with Bayesian priors from both modern and ancient genetic data we simulated a range of probable population sizes and mutation rates through time. Our simulations suggest that regional mitochondrial diversity has remained relatively constant even through climatic fluctuations of recent millennia.

  6. Ancient DNA assessment of tiger salamander population in Yellowstone National Park.

    Directory of Open Access Journals (Sweden)

    Sarah K McMenamin

    Full Text Available Recent data indicates that blotched tiger salamanders (Ambystoma tigrinum melanostictum in northern regions of Yellowstone National Park are declining due to climate-related habitat changes. In this study, we used ancient and modern mitochondrial haplotype diversity to model the effective size of this amphibian population through recent geological time and to assess past responses to climatic changes in the region. Using subfossils collected from a cave in northern Yellowstone, we analyzed >700 base pairs of mitochondrial sequence from 16 samples ranging in age from 100 to 3300 years old and found that all shared an identical haplotype. Although mitochondrial diversity was extremely low within the living population, we still were able to detect geographic subdivision within the local area. Using serial coalescent modelling with Bayesian priors from both modern and ancient genetic data we simulated a range of probable population sizes and mutation rates through time. Our simulations suggest that regional mitochondrial diversity has remained relatively constant even through climatic fluctuations of recent millennia.

  7. Crosslinks rather than strand breaks determine access to ancient DNA sequences from frozen sediments

    DEFF Research Database (Denmark)

    Hansen, Anders Johannes; Mitchell, D.L.; Wiuf, C.

    2006-01-01

    Diagenesis was studied in DNA obtained from Siberian permafrost (permanently frozen soil) ranging from 10 to 400 thousand years in age. Despite optimal preservation conditions, we found the sedimentary DNA to be severely modified by interstrand crosslinks, single and double stranded breaks, and f...

  8. An ancient icon reveals new mysteries: mummy DNA resurrects a cryptic species within the Nile crocodile.

    Science.gov (United States)

    Hekkala, Evon; Shirley, Matthew H; Amato, George; Austin, James D; Charter, Suellen; Thorbjarnarson, John; Vliet, Kent A; Houck, Marlys L; Desalle, Rob; Blum, Michael J

    2011-10-01

    The Nile crocodile (Crocodylus niloticus) is an ancient icon of both cultural and scientific interest. The species is emblematic of the great civilizations of the Nile River valley and serves as a model for international wildlife conservation. Despite its familiarity, a centuries-long dispute over the taxonomic status of the Nile crocodile remains unresolved. This dispute not only confounds our understanding of the origins and biogeography of the 'true crocodiles' of the crown genus Crocodylus, but also complicates conservation and management of this commercially valuable species. We have taken a total evidence approach involving phylogenetic analysis of mitochondrial and nuclear markers, as well as karyotype analysis of chromosome number and structure, to assess the monophyletic status of the Nile crocodile. Samples were collected from throughout Africa, covering all major bioregions. We also utilized specimens from museum collections, including mummified crocodiles from the ancient Egyptian temples at Thebes and the Grottes de Samoun, to reconstruct the genetic profiles of extirpated populations. Our analyses reveal a cryptic evolutionary lineage within the Nile crocodile that elucidates the biogeographic history of the genus and clarifies long-standing arguments over the species' taxonomic identity and conservation status. An examination of crocodile mummy haplotypes indicates that the cryptic lineage corresponds to an earlier description of C. suchus and suggests that both African Crocodylus lineages historically inhabited the Nile River. Recent survey efforts indicate that C. suchus is declining or extirpated throughout much of its distribution. Without proper recognition of this cryptic species, current sustainable use-based management policies for the Nile crocodile may do more harm than good.

  9. Mitochondrial DNA Reveals the Trace of the Ancient Settlers of a Violently Devastated Late Bronze and Iron Ages Village.

    Science.gov (United States)

    Núñez, Carolina; Baeta, Miriam; Cardoso, Sergio; Palencia-Madrid, Leire; García-Romero, Noemí; Llanos, Armando; M de Pancorbo, Marian

    2016-01-01

    La Hoya (Alava, Basque Country) was one of the most important villages of the Late Bronze and Iron Ages of the north of the Iberian Peninsula, until it was violently devastated around the 4th century and abandoned in the 3rd century B.C. Archaeological evidences suggest that descendants from La Hoya placed their new settlement in a nearby hill, which gave rise to the current village of Laguardia. In this study, we have traced the genetic imprints of the extinct inhabitants of La Hoya through the analysis of maternal lineages. In particular, we have analyzed the mitochondrial DNA (mtDNA) control region of 41 human remains recovered from the archaeological site for comparison with a sample of 51 individuals from the geographically close present-day population of Laguardia, as well as 56 individuals of the general population of the province of Alava, where the archaeological site and Laguardia village are located. MtDNA haplotypes were successfully obtained in 25 out of 41 ancient samples, and 14 different haplotypes were identified. The major mtDNA subhaplogroups observed in La Hoya were H1, H3, J1 and U5, which show a distinctive frequency pattern in the autochthonous populations of the north of the Iberian Peninsula. Approximate Bayesian Computation analysis was performed to test the most likely model for the local demographic history. The results did not sustain a genealogical continuity between Laguardia and La Hoya at the haplotype level, although factors such as sampling effects, recent admixture events, and genetic bottlenecks need to be considered. Likewise, the highly similar subhaplogroup composition detected between La Hoya and Laguardia and Alava populations do not allow us to reject a maternal genetic continuity in the human groups of the area since at least the Iron Age to present times. Broader analyses, based on a larger collection of samples and genetic markers, would be required to study fine-scale population events in these human groups.

  10. Nuclear DNA replication initiation in kinetoplastid parasites: new insights into an ancient process.

    Science.gov (United States)

    Tiengwe, Calvin; Marques, Catarina A; McCulloch, Richard

    2014-01-01

    Nuclear DNA replication is, arguably, the central cellular process in eukaryotes, because it drives propagation of life and intersects with many other genome reactions. Perhaps surprisingly, our understanding of nuclear DNA replication in kinetoplastids was limited until a clutch of studies emerged recently, revealing new insight into both the machinery and genome-wide coordination of the reaction. Here, we discuss how these studies suggest that the earliest acting components of the kinetoplastid nuclear DNA replication machinery - the factors that demarcate sites of the replication initiation, termed origins - are diverged from model eukaryotes. In addition, we discuss how origin usage and replication dynamics relate to the highly unusual organisation of transcription in the genome of Trypanosoma brucei.

  11. The last Viking King: a royal maternity case solved by ancient DNA analysis

    DEFF Research Database (Denmark)

    Dissing, Jørgen; Binladen, Jonas; Hansen, Anders;

    2006-01-01

    Estridsen to haplogroup H; Estrid's sequence differed from that of Sven at two positions in HVR-1, 16093T-->C and 16304T-->C, indicating that she belongs to subgroup H5a. Given the maternal inheritance of mtDNA, offspring will have the same mtDNA sequence as their mother with the exception of rare cases...... (approximately 35 years) at the time of death than the 70 years history records tell. Although the entombed woman cannot be the Estrid, she may well be one of Sven's two daughters-in-law who were also called Estrid and who both became queens....

  12. A comparative study of ancient environmental DNA to pollen and macrofossils from lake sediments reveals taxonomic overlap and additional plant taxa

    DEFF Research Database (Denmark)

    Pedersen, M.W.; Ginolhac, A.; Orlando, L.

    2013-01-01

    We use 2nd generation sequencing technology on sedimentary ancient DNA (. sedaDNA) from a lake in South Greenland to reconstruct the local floristic history around a low-arctic lake and compare the results with those previously obtained from pollen and macrofossils in the same lake. Thirty...... and Asparagaceae) are absent from the pollen and macrofossil records. An age model for the sediment based on twelve radiocarbon dates establishes a chronology and shows that the lake record dates back to 10,650calyrBP. Our results suggest that sedaDNA analysis from lake sediments, although taxonomically less...

  13. Novel contribution on the diagenetic physicochemical features of bone and teeth minerals, as substrates for ancient DNA typing.

    Science.gov (United States)

    Grunenwald, A; Keyser, C; Sautereau, A M; Crubézy, E; Ludes, B; Drouet, C

    2014-07-01

    The extraction of DNA from skeletal remains is a major step in archeological or forensic contexts. However, diagenesis of mineralized tissues often compromises this task although bones and teeth may represent preservation niches allowing DNA to persist over a wide timescale. This exceptional persistence is not only explained on the basis of complex organo-mineral interactions through DNA adsorption on apatite crystals composing the mineral part of bones and teeth but is also linked to environmental factors such as low temperatures and/or a dry environment. The preservation of the apatite phase itself, as an adsorption substrate, is another crucial factor susceptible to significantly impact the retrieval of DNA. With the view to bring physicochemical evidence of the preservation or alteration of diagenetic biominerals, we developed here an analytical approach on various skeletal specimens (ranging from ancient archeological samples to recent forensic specimens), allowing us to highlight several diagenetic indices so as to better apprehend the complexity of bone diagenesis. Based on complementary techniques (X-ray diffraction (XRD), Fourier transform infrared (FTIR), calcium and phosphate titrations, SEM-EDX, and gravimetry), we have identified specific indices that allow differentiating 11 biological samples, primarily according to the crystallinity and maturation state of the apatite phase. A good correlation was found between FTIR results from the analysis of the v3(PO4) and v4(PO4) vibrational domains and XRD-based crystallinity features. A maximal amount of information has been sought from this analytical approach, by way of optimized posttreatment of the data (spectral subtraction and enhancement of curve-fitting parameters). The good overall agreement found between all techniques leads to a rather complete picture of the diagenetic changes undergone by these 11 skeletal specimens. Although the heterogeneity and scarcity of the studied samples did not allow us

  14. Early population differentiation in extinct aborigines from Tierra del Fuego-Patagonia: ancient mtDNA sequences and Y-chromosome STR characterization.

    Science.gov (United States)

    García-Bour, Jaume; Pérez-Pérez, Alejandro; Alvarez, Sara; Fernández, Eva; López-Parra, Ana María; Arroyo-Pardo, Eduardo; Turbón, Daniel

    2004-04-01

    Ancient mtDNA was successfully recovered from 24 skeletal samples of a total of 60 ancient individuals from Patagonia-Tierra del Fuego, dated to 100-400 years BP, for which consistent amplifications and two-strand sequences were obtained. Y-chromosome STRs (DYS434, DYS437, DYS439, DYS393, DYS391, DYS390, DYS19, DYS389I, DYS389II, and DYS388) and the biallelic system DYS199 were also amplified, Y-STR alleles could be characterized in nine cases, with an average of 4.1 loci per sample correctly typed. In two samples of the same ethnic group (Aonikenk), an identical and complete eight-loci haplotype was recovered. The DYS199 biallelic system was used as a control of contamination by modern DNA and, along with DYS19, as a marker of American origin. The analysis of both mtDNA and Y-STRs revealed DNA from Amerindian ancestry. The observed polymorphisms are consistent with the hypothesis that the ancient Fuegians are close to populations from south-central Chile and Argentina, but their high nucleotide diversity and the frequency of single lineages strongly support early genetic differentiation of the Fuegians through combined processes of population bottleneck, isolation, and/or migration, followed by strong genetic drift. This suggests an early genetic diversification of the Fuegians right after their arrival at the southernmost extreme of South America.

  15. Ancient DNA reveals that the genetic structure of the northern Han Chinese was shaped prior to 3,000 years ago.

    Science.gov (United States)

    Zhao, Yong-Bin; Zhang, Ye; Zhang, Quan-Chao; Li, Hong-Jie; Cui, Ying-Qiu; Xu, Zhi; Jin, Li; Zhou, Hui; Zhu, Hong

    2015-01-01

    The Han Chinese are the largest ethnic group in the world, and their origins, development, and expansion are complex. Many genetic studies have shown that Han Chinese can be divided into two distinct groups: northern Han Chinese and southern Han Chinese. The genetic history of the southern Han Chinese has been well studied. However, the genetic history of the northern Han Chinese is still obscure. In order to gain insight into the genetic history of the northern Han Chinese, 89 human remains were sampled from the Hengbei site which is located in the Central Plain and dates back to a key transitional period during the rise of the Han Chinese (approximately 3,000 years ago). We used 64 authentic mtDNA data obtained in this study, 27 Y chromosome SNP data profiles from previously studied Hengbei samples, and genetic datasets of the current Chinese populations and two ancient northern Chinese populations to analyze the relationship between the ancient people of Hengbei and present-day northern Han Chinese. We used a wide range of population genetic analyses, including principal component analyses, shared mtDNA haplotype analyses, and geographic mapping of maternal genetic distances. The results show that the ancient people of Hengbei bore a strong genetic resemblance to present-day northern Han Chinese and were genetically distinct from other present-day Chinese populations and two ancient populations. These findings suggest that the genetic structure of northern Han Chinese was already shaped 3,000 years ago in the Central Plain area.

  16. Ancient DNA suggests the leading role played by men in the Neolithic dissemination.

    Science.gov (United States)

    Lacan, Marie; Keyser, Christine; Ricaut, François-Xavier; Brucato, Nicolas; Tarrús, Josep; Bosch, Angel; Guilaine, Jean; Crubézy, Eric; Ludes, Bertrand

    2011-11-08

    The impact of the Neolithic dispersal on the western European populations is subject to continuing debate. To trace and date genetic lineages potentially brought during this transition and so understand the origin of the gene pool of current populations, we studied DNA extracted from human remains excavated in a Spanish funeral cave dating from the beginning of the fifth millennium B.C. Thanks to a "multimarkers" approach based on the analysis of mitochondrial and nuclear DNA (autosomes and Y-chromosome), we obtained information on the early Neolithic funeral practices and on the biogeographical origin of the inhumed individuals. No close kinship was detected. Maternal haplogroups found are consistent with pre-Neolithic settlement, whereas the Y-chromosomal analyses permitted confirmation of the existence in Spain approximately 7,000 y ago of two haplogroups previously associated with the Neolithic transition: G2a and E1b1b1a1b. These results are highly consistent with those previously found in Neolithic individuals from French Late Neolithic individuals, indicating a surprising temporal genetic homogeneity in these groups. The high frequency of G2a in Neolithic samples in western Europe could suggest, furthermore, that the role of men during Neolithic dispersal could be greater than currently estimated.

  17. Phylogeny and ancient DNA of Sus provides insights into neolithic expansion in Island Southeast Asia and Oceania

    Science.gov (United States)

    Larson, Greger; Cucchi, Thomas; Fujita, Masakatsu; Matisoo-Smith, Elizabeth; Robins, Judith; Anderson, Atholl; Rolett, Barry; Spriggs, Matthew; Dolman, Gaynor; Kim, Tae-Hun; Thuy, Nguyen Thi Dieu; Randi, Ettore; Doherty, Moira; Due, Rokus Awe; Bollt, Robert; Djubiantono, Tony; Griffin, Bion; Intoh, Michiko; Keane, Emile; Kirch, Patrick; Li, Kuang-Ti; Morwood, Michael; Pedriña, Lolita M.; Piper, Philip J.; Rabett, Ryan J.; Shooter, Peter; Van den Bergh, Gert; West, Eric; Wickler, Stephen; Yuan, Jing; Cooper, Alan; Dobney, Keith

    2007-01-01

    Human settlement of Oceania marked the culmination of a global colonization process that began when humans first left Africa at least 90,000 years ago. The precise origins and dispersal routes of the Austronesian peoples and the associated Lapita culture remain contentious, and numerous disparate models of dispersal (based primarily on linguistic, genetic, and archeological data) have been proposed. Here, through the use of mtDNA from 781 modern and ancient Sus specimens, we provide evidence for an early human-mediated translocation of the Sulawesi warty pig (Sus celebensis) to Flores and Timor and two later separate human-mediated dispersals of domestic pig (Sus scrofa) through Island Southeast Asia into Oceania. Of the later dispersal routes, one is unequivocally associated with the Neolithic (Lapita) and later Polynesian migrations and links modern and archeological Javan, Sumatran, Wallacean, and Oceanic pigs with mainland Southeast Asian S. scrofa. Archeological and genetic evidence shows these pigs were certainly introduced to islands east of the Wallace Line, including New Guinea, and that so-called “wild” pigs within this region are most likely feral descendants of domestic pigs introduced by early agriculturalists. The other later pig dispersal links mainland East Asian pigs to western Micronesia, Taiwan, and the Philippines. These results provide important data with which to test current models for human dispersal in the region. PMID:17360400

  18. Ancient DNA analysis reveals high frequency of European lactase persistence allele (T-13910 in medieval central europe.

    Directory of Open Access Journals (Sweden)

    Annina Krüttli

    Full Text Available Ruminant milk and dairy products are important food resources in many European, African, and Middle Eastern societies. These regions are also associated with derived genetic variants for lactase persistence. In mammals, lactase, the enzyme that hydrolyzes the milk sugar lactose, is normally down-regulated after weaning, but at least five human populations around the world have independently evolved mutations regulating the expression of the lactase-phlorizin-hydrolase gene. These mutations result in a dominant lactase persistence phenotype and continued lactase tolerance in adulthood. A single nucleotide polymorphism (SNP at C/T-13910 is responsible for most lactase persistence in European populations, but when and where the T-13910 polymorphism originated and the evolutionary processes by which it rose to high frequency in Europe have been the subject of strong debate. A history of dairying is presumed to be a prerequisite, but archaeological evidence is lacking. In this study, DNA was extracted from the dentine of 36 individuals excavated at a medieval cemetery in Dalheim, Germany. Eighteen individuals were successfully genotyped for the C/T-13910 SNP by molecular cloning and sequencing, of which 13 (72% exhibited a European lactase persistence genotype: 44% CT, 28% TT. Previous ancient DNA-based studies found that lactase persistence genotypes fall below detection levels in most regions of Neolithic Europe. Our research shows that by AD 1200, lactase persistence frequency had risen to over 70% in this community in western Central Europe. Given that lactase persistence genotype frequency in present-day Germany and Austria is estimated at 71-80%, our results suggest that genetic lactase persistence likely reached modern levels before the historic population declines associated with the Black Death, thus excluding plague-associated evolutionary forces in the rise of lactase persistence in this region. This new evidence sheds light on the dynamic

  19. Ancient DNA analysis reveals high frequency of European lactase persistence allele (T-13910) in medieval central europe.

    Science.gov (United States)

    Krüttli, Annina; Bouwman, Abigail; Akgül, Gülfirde; Della Casa, Philippe; Rühli, Frank; Warinner, Christina

    2014-01-01

    Ruminant milk and dairy products are important food resources in many European, African, and Middle Eastern societies. These regions are also associated with derived genetic variants for lactase persistence. In mammals, lactase, the enzyme that hydrolyzes the milk sugar lactose, is normally down-regulated after weaning, but at least five human populations around the world have independently evolved mutations regulating the expression of the lactase-phlorizin-hydrolase gene. These mutations result in a dominant lactase persistence phenotype and continued lactase tolerance in adulthood. A single nucleotide polymorphism (SNP) at C/T-13910 is responsible for most lactase persistence in European populations, but when and where the T-13910 polymorphism originated and the evolutionary processes by which it rose to high frequency in Europe have been the subject of strong debate. A history of dairying is presumed to be a prerequisite, but archaeological evidence is lacking. In this study, DNA was extracted from the dentine of 36 individuals excavated at a medieval cemetery in Dalheim, Germany. Eighteen individuals were successfully genotyped for the C/T-13910 SNP by molecular cloning and sequencing, of which 13 (72%) exhibited a European lactase persistence genotype: 44% CT, 28% TT. Previous ancient DNA-based studies found that lactase persistence genotypes fall below detection levels in most regions of Neolithic Europe. Our research shows that by AD 1200, lactase persistence frequency had risen to over 70% in this community in western Central Europe. Given that lactase persistence genotype frequency in present-day Germany and Austria is estimated at 71-80%, our results suggest that genetic lactase persistence likely reached modern levels before the historic population declines associated with the Black Death, thus excluding plague-associated evolutionary forces in the rise of lactase persistence in this region. This new evidence sheds light on the dynamic evolutionary

  20. Molecular dating of caprines using ancient DNA sequences of Myotragus balearicus, an extinct endemic Balearic mammal

    Directory of Open Access Journals (Sweden)

    Alcover Josep Antoni

    2005-12-01

    Full Text Available Abstract Background Myotragus balearicus was an endemic bovid from the Balearic Islands (Western Mediterranean that became extinct around 6,000-4,000 years ago. The Myotragus evolutionary lineage became isolated in the islands most probably at the end of the Messinian crisis, when the desiccation of the Mediterranean ended, in a geological date established at 5.35 Mya. Thus, the sequences of Myotragus could be very valuable for calibrating the mammalian mitochondrial DNA clock and, in particular, the tree of the Caprinae subfamily, to which Myotragus belongs. Results We have retrieved the complete mitochondrial cytochrome b gene (1,143 base pairs, plus fragments of the mitochondrial 12S gene and the nuclear 28S rDNA multi-copy gene from a well preserved Myotragus subfossil bone. The best resolved phylogenetic trees, obtained with the cytochrome b gene, placed Myotragus in a position basal to the Ovis group. Using the calibration provided by the isolation of Balearic Islands, we calculated that the initial radiation of caprines can be dated at 6.2 ± 0.4 Mya. In addition, alpine and southern chamois, considered until recently the same species, split around 1.6 ± 0.3 Mya, indicating that the two chamois species have been separated much longer than previously thought. Conclusion Since there are almost no extant endemic mammals in Mediterranean islands, the sequence of the extinct Balearic endemic Myotragus has been crucial for allowing us to use the Messinian crisis calibration point for dating the caprines phylogenetic tree.

  1. Ancient DNA from 8400 Year-Old Çatalhöyük Wheat: Implications for the Origin of Neolithic Agriculture.

    Science.gov (United States)

    Bilgic, Hatice; Hakki, Erdogan E; Pandey, Anamika; Khan, Mohd Kamran; Akkaya, Mahinur S

    2016-01-01

    Human history was transformed with the advent of agriculture in the Fertile Crescent with wheat as one of the founding crops. Although the Fertile Crescent is renowned as the center of wheat domestication, archaeological studies have shown the crucial involvement of Çatalhöyük in this process. This site first gained attention during the 1961-65 excavations due to the recovery of primitive hexaploid wheat. However, despite the seeds being well preserved, a detailed archaeobotanical description of the samples is missing. In this article, we report on the DNA isolation, amplification and sequencing of ancient DNA of charred wheat grains from Çatalhöyük and other Turkish archaeological sites and the comparison of these wheat grains with contemporary wheat species including T. monococcum, T. dicoccum, T. dicoccoides, T. durum and T. aestivum at HMW glutenin protein loci. These ancient samples represent the oldest wheat sample sequenced to date and the first ancient wheat sample from the Middle East. Remarkably, the sequence analysis of the short DNA fragments preserved in seeds that are approximately 8400 years old showed that the Çatalhöyük wheat stock contained hexaploid wheat, which is similar to contemporary hexaploid wheat species including both naked (T. aestivum) and hulled (T. spelta) wheat. This suggests an early transitory state of hexaploid wheat agriculture from the Fertile Crescent towards Europe spanning present-day Turkey.

  2. Assessment of the extirpated Maritimes walrus using morphological and ancient DNA analysis.

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    Brenna A McLeod

    Full Text Available Species biogeography is a result of complex events and factors associated with climate change, ecological interactions, anthropogenic impacts, physical geography, and evolution. To understand the contemporary biogeography of a species, it is necessary to understand its history. Specimens from areas of localized extinction are important, as extirpation of species from these areas may represent the loss of unique adaptations and a distinctive evolutionary trajectory. The walrus (Odobenus rosmarus has a discontinuous circumpolar distribution in the arctic and subarctic that once included the southeastern Canadian Maritimes region. However, exploitation of the Maritimes population during the 16th-18th centuries led to extirpation, and the species has not inhabited areas south of 55°N for ∼250 years. We examined genetic and morphological characteristics of specimens from the Maritimes, Atlantic (O. r. rosmarus and Pacific (O. r. divergens populations to test the hypothesis that the first group was distinctive. Analysis of Atlantic and Maritimes specimens indicated that most skull and mandibular measurements were significantly different between the Maritimes and Atlantic groups and discriminant analysis of principal components confirmed them as distinctive groups, with complete isolation of skull features. The Maritimes walrus appear to have been larger animals, with larger and more robust tusks, skulls and mandibles. The mtDNA control region haplotypes identified in Maritimes specimens were unique to the region and a greater average number of nucleotide differences were found between the regions (Atlantic and Maritimes than within either group. Levels of diversity (h and π were lower in the Maritimes, consistent with other studies of species at range margins. Our data suggest that the Maritimes walrus was a morphologically and genetically distinctive group that was on a different evolutionary path from other walrus found in the north Atlantic.

  3. Ancient DNA Analysis of 8000 B.C. Near Eastern Farmers Supports an Early Neolithic Pioneer Maritime Colonization of Mainland Europe through Cyprus and the Aegean Islands

    Science.gov (United States)

    Fernández, Eva; Pérez-Pérez, Alejandro; Gamba, Cristina; Prats, Eva; Cuesta, Pedro; Anfruns, Josep; Molist, Miquel; Arroyo-Pardo, Eduardo; Turbón, Daniel

    2014-01-01

    The genetic impact associated to the Neolithic spread in Europe has been widely debated over the last 20 years. Within this context, ancient DNA studies have provided a more reliable picture by directly analyzing the protagonist populations at different regions in Europe. However, the lack of available data from the original Near Eastern farmers has limited the achieved conclusions, preventing the formulation of continental models of Neolithic expansion. Here we address this issue by presenting mitochondrial DNA data of the original Near-Eastern Neolithic communities with the aim of providing the adequate background for the interpretation of Neolithic genetic data from European samples. Sixty-three skeletons from the Pre Pottery Neolithic B (PPNB) sites of Tell Halula, Tell Ramad and Dja'de El Mughara dating between 8,700–6,600 cal. B.C. were analyzed, and 15 validated mitochondrial DNA profiles were recovered. In order to estimate the demographic contribution of the first farmers to both Central European and Western Mediterranean Neolithic cultures, haplotype and haplogroup diversities in the PPNB sample were compared using phylogeographic and population genetic analyses to available ancient DNA data from human remains belonging to the Linearbandkeramik-Alföldi Vonaldiszes Kerámia and Cardial/Epicardial cultures. We also searched for possible signatures of the original Neolithic expansion over the modern Near Eastern and South European genetic pools, and tried to infer possible routes of expansion by comparing the obtained results to a database of 60 modern populations from both regions. Comparisons performed among the 3 ancient datasets allowed us to identify K and N-derived mitochondrial DNA haplogroups as potential markers of the Neolithic expansion, whose genetic signature would have reached both the Iberian coasts and the Central European plain. Moreover, the observed genetic affinities between the PPNB samples and the modern populations of Cyprus and

  4. Sedimentary ancient DNA and pollen reveal the composition of plant organic matter in Late Quaternary permafrost sediments of the Buor Khaya Peninsula (north-eastern Siberia)

    Science.gov (United States)

    Hildegard Zimmermann, Heike; Raschke, Elena; Saskia Epp, Laura; Rosmarie Stoof-Leichsenring, Kathleen; Schwamborn, Georg; Schirrmeister, Lutz; Overduin, Pier Paul; Herzschuh, Ulrike

    2017-02-01

    Organic matter deposited in ancient, ice-rich permafrost sediments is vulnerable to climate change and may contribute to the future release of greenhouse gases; it is thus important to get a better characterization of the plant organic matter within such sediments. From a Late Quaternary permafrost sediment core from the Buor Khaya Peninsula, we analysed plant-derived sedimentary ancient DNA (sedaDNA) to identify the taxonomic composition of plant organic matter, and undertook palynological analysis to assess the environmental conditions during deposition. Using sedaDNA, we identified 154 taxa and from pollen and non-pollen palynomorphs we identified 83 taxa. In the deposits dated between 54 and 51 kyr BP, sedaDNA records a diverse low-centred polygon plant community including recurring aquatic pond vegetation while from the pollen record we infer terrestrial open-land vegetation with relatively dry environmental conditions at a regional scale. A fluctuating dominance of either terrestrial or swamp and aquatic taxa in both proxies allowed the local hydrological development of the polygon to be traced. In deposits dated between 11.4 and 9.7 kyr BP (13.4-11.1 cal kyr BP), sedaDNA shows a taxonomic turnover to moist shrub tundra and a lower taxonomic richness compared to the older samples. Pollen also records a shrub tundra community, mostly seen as changes in relative proportions of the most dominant taxa, while a decrease in taxonomic richness was less pronounced compared to sedaDNA. Our results show the advantages of using sedaDNA in combination with palynological analyses when macrofossils are rarely preserved. The high resolution of the sedaDNA record provides a detailed picture of the taxonomic composition of plant-derived organic matter throughout the core, and palynological analyses prove valuable by allowing for inferences of regional environmental conditions.

  5. DNA analysis of a 30,000-year-old Urocitellus glacialis from northeastern Siberia reveals phylogenetic relationships between ancient and present-day arctic ground squirrels

    Science.gov (United States)

    Faerman, Marina; Bar-Gal, Gila Kahila; Boaretto, Elisabetta; Boeskorov, Gennady G.; Dokuchaev, Nikolai E.; Ermakov, Oleg A.; Golenishchev, Fedor N.; Gubin, Stanislav V.; Mintz, Eugenia; Simonov, Evgeniy; Surin, Vadim L.; Titov, Sergei V.; Zanina, Oksana G.; Formozov, Nikolai A.

    2017-01-01

    In contrast to the abundant fossil record of arctic ground squirrels, Urocitellus parryii, from eastern Beringia, only a limited number of fossils is known from its western part. In 1946, unnamed GULAG prisoners discovered a nest with three mummified carcasses of arctic ground squirrels in the permafrost sediments of the El’ga river, Yakutia, Russia, that were later attributed to a new species, Citellus (Urocitellus) glacialis Vinogr. To verify this assignment and to explore phylogenetic relationships between ancient and present-day arctic ground squirrels, we performed 14C dating and ancient DNA analyses of one of the El’ga mummies and four contemporaneous fossils from Duvanny Yar, northeastern Yakutia. Phylogenetic reconstructions, based on complete cytochrome b gene sequences of five Late Pleistocene arctic ground squirrels and those of modern U. parryii from 21 locations across western Beringia, provided no support for earlier proposals that ancient arctic ground squirrels from Siberia constitute a distinct species. In fact, we observed genetic continuity of the glacialis mitochondrial DNA lineage in modern U. parryii of the Kamchatka peninsula. When viewed in a broader geographic perspective, our findings provide new insights into the genetic history of U. parryii in Late Pleistocene Beringia. PMID:28205612

  6. Influence of climate warming on arctic mammals? New insights from ancient DNA studies of the collared lemming Dicrostonyx torquatus.

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    Stefan Prost

    Full Text Available BACKGROUND: Global temperature increased by approximately half a degree (Celsius within the last 150 years. Even this moderate warming had major impacts on Earth's ecological and biological systems, especially in the Arctic where the magnitude of abiotic changes even exceeds those in temperate and tropical biomes. Therefore, understanding the biological consequences of climate change on high latitudes is of critical importance for future conservation of the species living in this habitat. The past 25,000 years can be used as a model for such changes, as they were marked by prominent climatic changes that influenced geographical distribution, demographic history and pattern of genetic variation of many extant species. We sequenced ancient and modern DNA of the collared lemming (Dicrostonyx torquatus, which is a key species of the arctic biota, from a single site (Pymva Shor, Northern Pre Urals, Russia to see if climate warming events after the Last Glacial Maximum had detectable effects on the genetic variation of this arctic rodent species, which is strongly associated with a cold and dry climate. RESULTS: Using three dimensional network reconstructions we found a dramatic decline in genetic diversity following the LGM. Model-based approaches such as Approximate Bayesian Computation and Markov Chain Monte Carlo based Bayesian inference show that there is evidence for a population decline in the collared lemming following the LGM, with the population size dropping to a minimum during the Greenland Interstadial 1 (Bølling/Allerød warming phase at 14.5 kyrs BP. CONCLUSION: Our results show that previous climate warming events had a strong influence on genetic diversity and population size of collared lemmings. Due to its already severely compromised genetic diversity a similar population reduction as a result of the predicted future climate change could completely abolish the remaining genetic diversity in this population. Local population

  7. Pre-Columbian Population Dynamics and Cultural Development in South Coast Perú as Revealed by Analysis of Ancient DNA

    OpenAIRE

    Fehren-Schmitz, Lars

    2012-01-01

    In this paper I report on a study whose principal aim is to understand the development and decline of the southern Peruvian Nasca culture in the upper Río Grande de Nasca drainage, and its cultural and biological affinities to the preceding Paracas culture. Ancient DNA analyses were conducted on over 300 pre-Columbian individuals from various cemeteries in southern Perú, from periods ranging from the Formative Period to the Middle Horizon. Our results show that the Nasca populations are close...

  8. Analysis of the three Yersinia pestis CRISPR loci provides new tools for phylogenetic studies and possibly for the investigation of ancient DNA.

    Science.gov (United States)

    Vergnaud, Gilles; Li, Yanjun; Gorgé, Olivier; Cui, Yujun; Song, Yajun; Zhou, Dongsheng; Grissa, Ibtissem; Dentovskaya, Svetlana V; Platonov, Mikhail E; Rakin, Alexander; Balakhonov, Sergey V; Neubauer, Heinrich; Pourcel, Christine; Anisimov, Andrey P; Yang, Ruifu

    2007-01-01

    The precise nature of the pathogen having caused early plague pandemics is uncertain. Although Yersinia pestis is a likely candidate for all three plague pandemics, the very rare direct evidence that can be deduced from ancient DNA (aDNA) analysis is controversial. Moreover, which of the three biovars, Antiqua, Medievalis or Orientalis, was associated with these pandemics is still debated. There is a need for phylogenetic analysis performed on Y. pestis strains isolated from countries from which plague probably arose and is still endemic. In addition there exist technical difficulties inherent to aDNA investigations and a lack of appropriate genetic targets. The recently described CRISPRs (clustered regularly interspaced short palindromic repeats) may represent such a target. CRISPR loci consist of a succession of highly conserved regions separated by specific "spacers" usually of viral origin. To be of use, data describing the mechanisms of evolution and diversity of CRISPRs in Y. pestis, its closest neighbors, and other species which might contaminate ancient DNA, are necessary. The investigation of closely related Y. pestis isolates has revealed recent mutation events in which elements constituting CRISPRs were acquired or lost, providing essential insight on their evolution. Rules deduced represent the basis for subsequent interpretation. In the present study, the CRISPR loci from representative Y. pestis and Yersinia pseudotuberculosis strains were investigated by PCR amplification and sequence analysis. The investigation of this wider panel of strains, including other subspecies or ecotypes within Y. pestis and also Y. pseudotuberculosis strains provides a database of the existing CRISPR spacers and helps predict the expected CRISPR structure of the Y. pestis ancestor. This knowledge will open the way to the development of a spoligotyping assay, in which spacers can be amplified even from highly degraded DNA samples. The data obtained show that CRISPR

  9. Tamil merchant in ancient Mesopotamia.

    Directory of Open Access Journals (Sweden)

    Malliya Gounder Palanichamy

    Full Text Available Recent analyses of ancient Mesopotamian mitochondrial genomes have suggested a genetic link between the Indian subcontinent and Mesopotamian civilization. There is no consensus on the origin of the ancient Mesopotamians. They may be descendants of migrants, who founded regional Mesopotamian groups like that of Terqa or they may be merchants who were involved in trans Mesopotamia trade. To identify the Indian source population showing linkage to the ancient Mesopotamians, we screened a total of 15,751 mitochondrial DNAs (11,432 from the literature and 4,319 from this study representing all major populations of India. Our results although suggest that south India (Tamil Nadu and northeast India served as the source of the ancient Mesopotamian mtDNA gene pool, mtDNA of these ancient Mesopotamians probably contributed by Tamil merchants who were involved in the Indo-Roman trade.

  10. Tamil merchant in ancient Mesopotamia.

    Science.gov (United States)

    Palanichamy, Malliya Gounder; Mitra, Bikash; Debnath, Monojit; Agrawal, Suraksha; Chaudhuri, Tapas Kumar; Zhang, Ya-Ping

    2014-01-01

    Recent analyses of ancient Mesopotamian mitochondrial genomes have suggested a genetic link between the Indian subcontinent and Mesopotamian civilization. There is no consensus on the origin of the ancient Mesopotamians. They may be descendants of migrants, who founded regional Mesopotamian groups like that of Terqa or they may be merchants who were involved in trans Mesopotamia trade. To identify the Indian source population showing linkage to the ancient Mesopotamians, we screened a total of 15,751 mitochondrial DNAs (11,432 from the literature and 4,319 from this study) representing all major populations of India. Our results although suggest that south India (Tamil Nadu) and northeast India served as the source of the ancient Mesopotamian mtDNA gene pool, mtDNA of these ancient Mesopotamians probably contributed by Tamil merchants who were involved in the Indo-Roman trade.

  11. Ancient Egypt.

    Science.gov (United States)

    Evers, Virginia

    This four-week fourth grade social studies unit dealing with religious dimensions in ancient Egyptian culture was developed by the Public Education Religion Studies Center at Wright State University. It seeks to help students understand ancient Egypt by looking at the people, the culture, and the people's world view. The unit begins with outlines…

  12. Pre-whaling genetic diversity and population ecology in eastern Pacific gray whales: insights from ancient DNA and stable isotopes.

    Directory of Open Access Journals (Sweden)

    S Elizabeth Alter

    Full Text Available Commercial whaling decimated many whale populations, including the eastern Pacific gray whale, but little is known about how population dynamics or ecology differed prior to these removals. Of particular interest is the possibility of a large population decline prior to whaling, as such a decline could explain the ~5-fold difference between genetic estimates of prior abundance and estimates based on historical records. We analyzed genetic (mitochondrial control region and isotopic information from modern and prehistoric gray whales using serial coalescent simulations and Bayesian skyline analyses to test for a pre-whaling decline and to examine prehistoric genetic diversity, population dynamics and ecology. Simulations demonstrate that significant genetic differences observed between ancient and modern samples could be caused by a large, recent population bottleneck, roughly concurrent with commercial whaling. Stable isotopes show minimal differences between modern and ancient gray whale foraging ecology. Using rejection-based Approximate Bayesian Computation, we estimate the size of the population bottleneck at its minimum abundance and the pre-bottleneck abundance. Our results agree with previous genetic studies suggesting the historical size of the eastern gray whale population was roughly three to five times its current size.

  13. Ancient DNA analyses of early archaeological sites in New Zealand reveal extreme exploitation of moa (Aves: Dinornithiformes) at all life stages

    Science.gov (United States)

    Oskam, Charlotte L.; Allentoft, Morten E.; Walter, Richard; Scofield, R. Paul; Haile, James; Holdaway, Richard N.; Bunce, Michael; Jacomb, Chris

    2012-10-01

    The human colonisation of New Zealand in the late thirteenth century AD led to catastrophic impacts on the local biota and is among the most compelling examples of human over-exploitation of native fauna, including megafauna. Nearly half of the species in New Zealand' s pre-human avifauna are now extinct, including all nine species of large, flightless moa (Aves: Dinornithiformes). The abundance of moa in early archaeological sites demonstrates the significance of these megaherbivores in the diet of the first New Zealanders. Combining moa assemblage data, based on DNA identification of eggshell and bone, with morphological identification of bone (literature and museum catalogued specimens), we present the most comprehensive audit of moa to date from several significant 13th-15th century AD archaeological deposits across the east coast of the South Island. Mitochondrial DNA (mtDNA) was amplified from 251 of 323 (78%) eggshell fragments and 22 of 27 (88%) bone samples, and the analyses revealed the presence of four moa species: Anomalopteryx didiformis; Dinornis robustus; Emeus crassus and Euryapteryx curtus. The mtDNA, along with polymorphic microsatellite markers, enabled an estimate of the minimum number of individual eggs consumed at each site. Remarkably, in one deposit over 50 individual eggs were identified - a number that likely represents a considerable proportion of the total reproductive output of moa in the area and emphasises that human predation of all life stages of moa was intense. Molecular sexing was conducted on bones (n = 11). Contrary to previous ancient DNA studies from natural sites that consistently report an excess of female moa, we observed an excess of males (2.7:1), suggestive that males were preferential targets. This could be related to different behaviour between the two highly size-dimorphic sexes in moa. Lastly, we investigated the moa species from recovered skeletal and eggshell remains from seven Wairau Bar burials, and identified

  14. Moa's Ark or volant ghosts of Gondwana? Insights from nineteen years of ancient DNA research on the extinct moa (Aves: Dinornithiformes) of New Zealand.

    Science.gov (United States)

    Allentoft, Morten E; Rawlence, Nicolas J

    2012-01-20

    The moa (Aves: Dinornithiformes) of New Zealand represent one of the extinct iconic taxa that define the field of ancient DNA (aDNA), and after almost two decades of genetic scrutiny of bones, feathers, coprolites, mummified tissue, eggshell, and sediments, our knowledge of these prehistoric giants has increased significantly. Thanks to molecular and morphological-based research, the insights that have been obtained into moa phylogenetics, phylogeography, and palaeobiology exceeds that of any other extinct taxon. This review documents the strengths of applying a multidisciplinary approach when studying extinct taxa but also shows that cross-disciplinary controversies still remain at the most fundamental levels, with highly conflicting interpretations derived from aDNA and morphology. Moa species diversity, for example, is still heavily debated, as well as their relationship with other ratites and the mode of radiation. In addition to increasing our knowledge on a lineage of extinct birds, further insights into these aspects can clarify some of the basal splits in avian evolution, and the evolutionary implications of the breakup of the prehistoric supercontinent Gondwana. Did a flightless moa ancestor drift away on proto New Zealand (Moa's Ark) or did a volant ancestor arrive by flight? Here we provide an overview of 19 years of aDNA research on moa, critically assess the attempts and controversies in placing the moa lineage among palaeognath birds, and discuss the factors that facilitated the extensive radiation of moa. Finally, we identify the most obvious gaps in the current knowledge to address the future potential research areas in moa genetics.

  15. Identification of Photosynthetic Plankton Communities Using Sedimentary Ancient DNA and Their Response to late-Holocene Climate Change on the Tibetan Plateau

    Science.gov (United States)

    Hou, Weiguo; Dong, Hailiang; Li, Gaoyuan; Yang, Jian; Coolen, Marco J. L.; Liu, Xingqi; Wang, Shang; Jiang, Hongchen; Wu, Xia; Xiao, Haiyi; Lian, Bin; Wan, Yunyang

    2014-10-01

    Sediments from Tibetan lakes in NW China are potentially sensitive recorders of climate change and its impact on ecosystem function. However, the important plankton members in many Tibetan Lakes do not make and leave microscopically diagnostic features in the sedimentary record. Here we established a taxon-specific molecular approach to specifically identify and quantify sedimentary ancient DNA (sedaDNA) of non-fossilized planktonic organisms preserved in a 5-m sediment core from Kusai Lake spanning the last 3100 years. The reliability of the approach was validated with multiple independent genetic markers. Parallel analyses of the geochemistry of the core and paleo-climate proxies revealed that Monsoon strength-driven changes in nutrient availability, temperature, and salinity as well as orbitally-driven changes in light intensity were all responsible for the observed temporal changes in the abundance of two dominant phytoplankton groups in the lake, Synechococcus (cyanobacteria) and Isochrysis (haptophyte algae). Collectively our data show that global and regional climatic events exhibited a strong influence on the paleoecology of phototrophic plankton in Kusai Lake.

  16. Identification of photosynthetic plankton communities using sedimentary ancient DNA and their response to late-Holocene climate change on the Tibetan Plateau.

    Science.gov (United States)

    Hou, Weiguo; Dong, Hailiang; Li, Gaoyuan; Yang, Jian; Coolen, Marco J L; Liu, Xingqi; Wang, Shang; Jiang, Hongchen; Wu, Xia; Xiao, Haiyi; Lian, Bin; Wan, Yunyang

    2014-10-17

    Sediments from Tibetan lakes in NW China are potentially sensitive recorders of climate change and its impact on ecosystem function. However, the important plankton members in many Tibetan Lakes do not make and leave microscopically diagnostic features in the sedimentary record. Here we established a taxon-specific molecular approach to specifically identify and quantify sedimentary ancient DNA (sedaDNA) of non-fossilized planktonic organisms preserved in a 5-m sediment core from Kusai Lake spanning the last 3100 years. The reliability of the approach was validated with multiple independent genetic markers. Parallel analyses of the geochemistry of the core and paleo-climate proxies revealed that Monsoon strength-driven changes in nutrient availability, temperature, and salinity as well as orbitally-driven changes in light intensity were all responsible for the observed temporal changes in the abundance of two dominant phytoplankton groups in the lake, Synechococcus (cyanobacteria) and Isochrysis (haptophyte algae). Collectively our data show that global and regional climatic events exhibited a strong influence on the paleoecology of phototrophic plankton in Kusai Lake.

  17. Interferometry with Strontium Ions

    Science.gov (United States)

    Jackson, Jarom; Lambert, Enoch; Otterstrom, Nils; Jones, Tyler; Durfee, Dallin

    2014-05-01

    We describe progress on a cold ion matter-wave interferometer. Cold Strontium atoms are extracted from an LVIS. The atoms will be photo-ionized with a two-photon transition to an auto-ionizing state in the continuum. The ions will be split and recombined using stimulated Raman transitions from a pair of diode lasers injection locked to two beams from a master laser which have been shifted up and down by half the hyperfine splitting. We are developing laser instrumentation for this project including a method to prevent mode-hopping by analyzing laser frequency noise, and an inexpensive, robust wavelength meter. Supported by NSF Award No. 1205736.

  18. DNA typing of ancient parasite eggs from environmental samples identifies human and animal worm infections in Viking-age settlement

    DEFF Research Database (Denmark)

    Søe, Martin Jensen; Fredensborg, Brian Lund; Nejsum, Peter;

    parasite eggs from environmental samples collected at a Viking-age settlement (1018-1030 A.D.) are DNA typed to the species level. The human whipworm (Trichuris trichiura) and the human roundworm (Ascaris lumbricoides) are identified indicating that these parasites were endemic in Denmark in the Viking...

  19. Ancient DNA Analyses Reveal Contrasting Phylogeographic Patterns amongst Kiwi (Apteryx spp.) and a Recently Extinct Lineage of Spotted Kiwi

    OpenAIRE

    Shepherd, Lara D; Worthy, Trevor H.; Tennyson, Alan J. D.; R Paul Scofield; Ramstad, Kristina M.; Lambert, David M.

    2012-01-01

    The little spotted kiwi (Apteryx owenii) is a flightless ratite formerly found throughout New Zealand but now greatly reduced in distribution. Previous phylogeographic studies of the related brown kiwi (A. mantelli, A. rowi and A. australis), with which little spotted kiwi was once sympatric, revealed extremely high levels of genetic structuring, with mitochondrial DNA haplotypes often restricted to populations. We surveyed genetic variation throughout the present and pre-human range of littl...

  20. Islands in the ice: detecting past vegetation on Greenlandic nunataks using historical records and sedimentary ancient DNA meta-barcoding.

    Science.gov (United States)

    Jørgensen, Tina; Kjaer, Kurt H; Haile, James; Rasmussen, Morten; Boessenkool, Sanne; Andersen, Kenneth; Coissac, Eric; Taberlet, Pierre; Brochmann, Christian; Orlando, Ludovic; Gilbert, M Thomas P; Willerslev, Eske

    2012-04-01

    Nunataks are isolated bedrocks protruding through ice sheets. They vary in age, but represent island environments in 'oceans' of ice through which organism dispersals and replacements can be studied over time. The J.A.D. Jensen's Nunataks at the southern Greenland ice sheet are the most isolated nunataks on the northern hemisphere - some 30 km from the nearest biological source. They constitute around 2 km(2) of ice-free land that was established in the early Holocene. We have investigated the changes in plant composition at these nunataks using both the results of surveys of the flora over the last 130 years and through reconstruction of the vegetation from the end of the Holocene Thermal Maximum (5528 ± 75 cal year BP) using meta-barcoding of plant DNA recovered from the nunatak sediments (sedaDNA). Our results show that several of the plant species detected with sedaDNA are described from earlier vegetation surveys on the nunataks (in 1878, 1967 and 2009). In 1967, a much higher biodiversity was detected than from any other of the studied periods. While this may be related to differences in sampling efforts for the oldest period, it is not the case when comparing the 1967 and 2009 levels where the botanical survey was exhaustive. As no animals and humans are found on the nunataks, this change in diversity over a period of just 42 years must relate to environmental changes probably being climate-driven. This suggests that even the flora of fairly small and isolated ice-free areas reacts quickly to a changing climate.

  1. Genetic characteristics and migration history of a bronze culture population in the West Liao-River valley revealed by ancient DNA.

    Science.gov (United States)

    Li, Hongjie; Zhao, Xin; Zhao, Yongbin; Li, Chunxiang; Si, Dayong; Zhou, Hui; Cui, Yinqiu

    2011-12-01

    In order to study the genetic characteristics of the Lower Xiajiadian culture (LXC) population, a main bronze culture branch in northern China dated 4500-3500 years ago, two uniparentally inherited markers, mitochondrial DNA and Y-chromosome single-nucleotide polymorphisms (Y-SNPs), were analyzed on 14 human remains excavated from the Dadianzi site. The 14 sequences, which contained 13 haplotypes, were assigned to 9 haplogroups, and Y-SNP typing of 5 male individuals assigned them to haplogroups N (M231) and O3 (M122). The results indicate that the LXC population mainly included people carrying haplogroups from northern Asia who had lived in this region since the Neolithic period, as well as genetic evidence of immigration from the Central Plain. Later in the Bronze Age, part of the population migrated to the south away from a cooler climate, which ultimately influenced the gene pool in the Central Plain. Thus, climate change is an important factor, which drove the population migration during the Bronze Age in northern China. Based on these results, the local genetic continuity did not seem to be affected by outward migration, although more data are needed especially from other ancient populations to determine the influence of return migration on genetic continuity.

  2. On the origin of Iberomaurusians: new data based on ancient mitochondrial DNA and phylogenetic analysis of Afalou and Taforalt populations.

    Science.gov (United States)

    Kefi, Rym; Hechmi, Meriem; Naouali, Chokri; Jmel, Haifa; Hsouna, Sana; Bouzaid, Eric; Abdelhak, Sonia; Beraud-Colomb, Eliane; Stevanovitch, Alain

    2016-12-30

    The Western North African population was characterized by the presence of Iberomaurusian civilization at the Epiplaeolithic period (around 20,000 years before present (YBP) to 10,000 YBP). The origin of this population is still not clear: they may come from Europe, Near East, sub-Saharan Africa or they could have evolved in situ in North Africa. With the aim to contribute to a better knowledge of the settlement of North Africa we analysed the mitochondrial DNA extracted from Iberomaurusian skeletons exhumed from the archaeological site of Afalou (AFA) (15,000-11,000 YBP) in Algeria and from the archaeological site of Taforalt (TAF) (23,000-10,800 YBP) in Morocco. Then, we carried out a phylogenetic analysis relating these Iberomaurusians to 61 current Mediterranean populations. The genetic structure of TAF and AFA specimens contains only North African and Eurasian maternal lineages. These finding demonstrate the presence of these haplotypes in North Africa from at least 20,000 YBP. The very low contribution of a Sub-Saharan African haplotype in the Iberomaurusian samples is confirmed. We also highlighted the existence of genetic flows between Southern and Northern coast of the Mediterranean.

  3. Strontium Carbonate Industry Needs Urgent Upgrade

    Institute of Scientific and Technical Information of China (English)

    Jin Tianxin

    2007-01-01

    @@ Strontium carbonate is an important inorganic chemical product mainly used in the manufacture of magnetic materials such as glass shell for picture tubes,cathode-ray tubes (CRT) for color TVs,electromagnets and strontium ferrite.

  4. Multiwavelength Strontium Vapor Lasers

    Science.gov (United States)

    Soldatov, A. N.; Yudin, N. A.

    2016-08-01

    Based on an analysis of experimental and theoretical works, modern notion on conditions of forming of population density inversion on self-terminating IR transitions of alkali-earth metals is given. It is demonstrated that there is a significant difference in the inversion formation in lasers on self-terminating transitions in the visible and near-IR ranges and lasers on self-terminating transitions of alkali-earth metals lasing IR lines in the mid-IR range. It is shown that in the discharge circuit of lasers on self-terminating metal atom transitions (LSMT) there are processes strengthening the influence of the known mechanism limiting the frequency and energy characteristics (FEC) of radiation caused by the presence of prepulse electron concentration. The mechanism of influence of these processes on FEC of the LSMT and technical methods of their neutralization are considered. The possibility of obtaining average lasing power of ~200 W from one liter volume of the active medium of the strontium vapor laser is demonstrated under conditions of neutralization of these processes.

  5. Polymeric strontium ranelate nonahydrate

    Directory of Open Access Journals (Sweden)

    Kenny Stahl

    2011-04-01

    Full Text Available The title compound, poly[[μ-aqua-tetraaqua{μ-5-[bis(carboxylatomethylamino]-3-carboxylatomethyl-4-cyanothiophene-2-carboxylato}distrontium(II] tetrahydrate], [Sr2(C12H6N2O8S(H2O5]·3.79H2O, crystallizes with nine- and eight-coordinated Sr2+ cations. They are bound to seven of the eight ranelate O atoms and five of the water molecules. The SrO8 and SrO9 polyhedra are interconnected by edge-sharing, forming hollow layers parallel to (011. The layers are, in turn, interconnected by ranelate anions, forming a metal–organic framework (MOF structure with channels along the a axis. The four water molecules not coordinated to strontium are located in these channels and hydrogen bonded to each other and to the ranelates. Part of the water H atoms are disordered. The compound dehydrates very easily and 0.210 (4 water molecules out of nine were lost during crystal mounting causing additional disorder in the water structure.

  6. Ancient Egypt

    Science.gov (United States)

    Swamy, Ashwin Balegar

    This thesis involves development of an interactive GIS (Geographic Information System) based application, which gives information about the ancient history of Egypt. The astonishing architecture, the strange burial rituals and their civilization were some of the intriguing questions that motivated me towards developing this application. The application is a historical timeline starting from 3100 BC, leading up to 664 BC, focusing on the evolution of the Egyptian dynasties. The tool holds information regarding some of the famous monuments which were constructed during that era and also about the civilizations that co-existed. It also provides details about the religions followed by their kings. It also includes the languages spoken during those periods. The tool is developed using JAVA, a programing language and MOJO (Map Objects Java Objects) a product of ESRI (Environmental Science Research Institute) to create map objects, to provide geographic information. JAVA Swing is used for designing the user interface. HTML (Hyper Text Markup Language) pages are created to provide the user with more information related to the historic period. CSS (Cascade Style Sheets) and JAVA Scripts are used with HTML5 to achieve creative display of content. The tool is kept simple and easy for the user to interact with. The tool also includes pictures and videos for the user to get a feel of the historic period. The application is built to motivate people to know more about one of the prominent and ancient civilization of the Mediterranean world.

  7. Synthesis and investigations of new strontium dicarboxylates

    Energy Technology Data Exchange (ETDEWEB)

    Grzesiak-Nowak, Marta [Polish Academy of Sciences, Krakow (Poland). Jerzy Haber Institute of Catalysis and Surface Chemistry; Nitek, Wojciech; Rafalska-Lasocha, Alicja [Jagiellonian Univ., Krakow (Poland). Faculty of Chemistry; Lasocha, Wieslaw [Polish Academy of Sciences, Krakow (Poland). Jerzy Haber Institute of Catalysis and Surface Chemistry; Jagiellonian Univ., Krakow (Poland). Faculty of Chemistry

    2013-07-01

    Using simple methods of synthesis without template agents, 6 new compounds of strontium and dicarboxylic acids have been obtained. The resulting salts are: {l_brace}1{r_brace} strontium glutarate pentahydrate, {l_brace}2{r_brace} strontium adipate, {l_brace}3{r_brace} strontium pimelate monohydrate, {l_brace}4{r_brace} strontium suberate, {l_brace}5{r_brace} strontium azelate and {l_brace}6{r_brace} strontium dodecanedioate hemihydrate. Similarly to the known barium compounds, starting from the salt of azelaic acid, strontium compounds with longer dicarboxylic acids form acidic salts. Metal centers have the coordination number C.N. = 8, and the coordination polyhedra are dodecahedra. Glutaric acid form layered material, whereas with use of longer acids 3D systems are formed. Acids such as dodecanedioic and azealic form systems in which Sr-O polyhedra do not share edges or vertices. Isolated SrO{sub 8} polyhedra are joined by carboxylic groups of dicarboxylic acids. Strontium salts {l_brace}2, 4, 5{r_brace} are anhydrous, but {l_brace}1{r_brace} is pentahydrate, {l_brace}3{r_brace} is monohydrate, and {l_brace}6{r_brace} is hemihydrate. During thermal decomposition strontium salts of dicarboxylic acids decompose through an unknown intermediate product to strontium carbonate. (orig.)

  8. Sorption of strontium on clinoptilolite and heulandite

    Energy Technology Data Exchange (ETDEWEB)

    Chernyavskaya, N.B.

    1986-05-01

    The author investigates the sorption of strontium on the isostructural zeolites clinoptilolite and heulandite. In the Sr/Na/zeolite/H/sub 2/O system, clinoptilolite manifests selectivity for strontium, and heulandite for sodium. The role of the nature of the exchange ions is discussed. Modification of the clinoptilolite with acid, subsequently obtaining the Na, NH/sub 4/, or N/sub 2/H/sub 4/ form, increases the capacity for strontium by a factor of 2-4.

  9. Genetic diversity among ancient Nordic populations.

    Science.gov (United States)

    Melchior, Linea; Lynnerup, Niels; Siegismund, Hans R; Kivisild, Toomas; Dissing, Jørgen

    2010-01-01

    Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13%) than among extant Danes and Scandinavians (approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  10. Solvothermal synthesis of strontium phosphate chloride nanowire

    Science.gov (United States)

    Lam, W. M.; Wong, C. T.; Li, Z. Y.; Luk, K. D. K.; Chan, W. K.; Yang, C.; Chiu, K. Y.; Xu, B.; Lu, W. W.

    2007-08-01

    Strontium phosphate chloride nanowire was synthesized via a solvothermal treatment of strontium tri-polyphosphate and Collin salt in 1,4-dioxane at 150 °C. The effects of 1,4-dioxane concentration on particle morphology, crystallinity and phase purity were investigated in this study. The specimen morphology was analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When the concentration of 1,4-dioxane was below 10%, micron-sized whisker was the dominant form. At 20-25% concentration of 1,4-dioxane, strontium phosphate chloride single-crystalline nanowire was 31±12 nm in diameter and 1.43±0.6 μm in length with an aspect ratio of 52.28±29.41. X-ray diffraction (XRD) pattern of this nanowire matched with that of strontium phosphate chloride (JCPDS #083-0973). When 1,4-dioxane concentration exceeded 25%, nanorod aggregate was the dominant form instead of nanowire. At 20-25% 1,4-dioxane concentration suitable strontium concentration combine with high chemical potential environment favors the formation of nanowires. By adding 1,4-dioxane impure phase such as β-strontium hydrogen phosphate, nanorod formation was suppressed. This method provides an efficient way to synthesize high aspect ratio strontium phosphate chloride nanowire. It has potential bioactive nanocomposite, high mechanical performance bioactive bone cement filler and fluorescent material applications.

  11. A 150-year record of ancient DNA, lipid biomarkers and hydrogen isotopes, tracing the microbial-planktonic community succession controlled by (hydro)climatic variability in a tropical lake

    Science.gov (United States)

    Smittenberg, Rienk; Yamoah, Kweku; Callac, Nolwenn; Fru, Ernest Chi; Chabangborn, Akkaneewut; Rattray, Jayne; Wohlfarth, Barbara

    2016-04-01

    We investigated the decadal variations in phytoplankton communities, and their response to environmental and climatic conditions, from a ˜150 year long sedimentary archive of Lake Nong Thale Prong (NTP), southern Thailand. We applied a combination of analyses: lipid biomarkers, compound-specific hydrogen isotopes, bulk carbon and nitrogen concentrations and isotopes, environmental SEM, and fossil DNA using qPCR targeted to specific taxa. Past hydrological conditions were reconstructed using the hydrogen isotopic composition of leaf wax n-alkanes. Temperatures were reconstructed using the tetraether-based MBT/CBT index, measured using a new and efficient reverse-phase HPLC-MS method. The climatological data compared well with meteorological data from the last decades. Reconstructed drier and warmer conditions from ˜1857-1916 Common Era (CE) coincided with oligotrophic lake water conditions and dominance of the green algae Botryococcus braunii - evidenced by a combination of both fossil DNA and the occurrence of characteristic botryococcene lipids. A change to higher silica (Si) input ˜1916 CE was related to increased rainfall and lower temperatures concurring with an abrupt takeover by diatom blooms lasting for 50 years - as evidenced by ancient DNA, characteristic highly branched isoprenoid lipids, and SEM. From the 1970s onwards, more eutrophic conditions prevailed, and these were likely caused by increased levels of anthropogenic phosphate (P), aided by stronger lake stratification caused by dryer and warmer conditions. The eutrophic conditions led to increased primary productivity in the lake, consisting again of a Botryococcus sp., although this time not producing botryococcene lipids. Moreover, Cyanobacteria became dominant - again evidenced by ancient DNA and the characteristic C19 alkane. Throughout the record, stratification and primary production could be linked to the intensity of methane cycling, by targeting and quantifying the mcrA gene that is used

  12. Illuminating the evolution of equids and rodents with next-generation sequencing of ancient specimens

    DEFF Research Database (Denmark)

    Mouatt, Julia Thidamarth Vilstrup

    The sequencing of ancient DNA provides perspectives on the genetic history of past populations and extinct species. However, ancient DNA research presents specific limitations mostly due to DNA survival, damage and contamination. Yet with stringent laboratory procedures, the sensitivity of target...

  13. Strontium Ions Substitution in Brushite Crystals: The Role of Strontium Chloride

    Directory of Open Access Journals (Sweden)

    Enrique López Cabarcos

    2011-05-01

    Full Text Available The incorporation of strontium chloride to brushite cement was successful to introduce strontium ions within the lattice of brushite crystals. The effect of strontium ions on brushite cement properties was concentration dependent; such that, the addition of 5% and 10% (w/w SrCl2 significantly increased the cement FST and the addition of 10% SrCl2 decreased the cement tensile strength. Further, cement weight loss was shown to be increased by cement modification with SrCl2. The combination of ionic substitution and the degradability of brushite cements would constitute a system for the local delivery of strontium ions in the treatment of osteoporosis.

  14. Strontium ions substitution in brushite crystals: the role of strontium chloride.

    Science.gov (United States)

    Alkhraisat, Mohammad H; Rueda, Carmen; López Cabarcos, Enrique

    2011-05-31

    The incorporation of strontium chloride to brushite cement was successful to introduce strontium ions within the lattice of brushite crystals. The effect of strontium ions on brushite cement properties was concentration dependent; such that, the addition of 5% and 10% (w/w) SrCl2 significantly increased the cement FST and the addition of 10% SrCl2 decreased the cement tensile strength. Further, cement weight loss was shown to be increased by cement modification with SrCl2. The combination of ionic substitution and the degradability of brushite cements would constitute a system for the local delivery of strontium ions in the treatment of osteoporosis.

  15. Surface adsorption in strontium chloride ammines

    DEFF Research Database (Denmark)

    Ammitzbøll, Andreas L.; Lysgaard, Steen; Klukowska, Agata

    2013-01-01

    An adsorbed state and its implications on the ab- and desorption kinetics of ammonia in strontium chloride ammine is identified using a combination of ammonia absorption measurements, thermogravimetric analysis, and density functional theory calculations. During thermogravimetric analysis, ammoni...

  16. Strontium clusters: electronic and geometry shell effects

    DEFF Research Database (Denmark)

    Lyalin, Andrey G.; Solov'yov, Ilia; Greiner, Walter

    2008-01-01

    is governed by an interplay of the electronic and geometry shell closures. Influence of the electronic shell effects on structural rearrangements can lead to violation of the icosahedral growth motif of strontium clusters. It is shown that the excessive charge essentially affects the optimized geometry......The optimized structure and electronic properties of neutral, singly and doubly charged strontium clusters have been investigated using it ab initio theoretical methods based on density-functional theory. We have systematically calculated the optimized geometries of neutral, singly and doubly...... charged strontium clusters consisting of up to 14 atoms, average bonding distances, electronic shell closures, binding energies per atom, and spectra of the density of electronic states (DOS). It is demonstrated that the size-evolution of structural and electronic properties of strontium clusters...

  17. Fixation of Radioactive Strontium in Soil

    DEFF Research Database (Denmark)

    Gregers-Hansen, Birte

    1964-01-01

    The contamination of agricultural areas by fission products from nuclear events is a possibility, and would in turn lead to contamination of plants. Of special importance is the long-lived strontium-90, as it has been shown1 that this isotope is taken up by plants to a much greater extent than an...... been considered6,7. In general, these methods appear to be of little practical value, except for deep ploughing and the liming of acid soils, both of which will reduce the strontium uptake by a factor of 3–4....... of the other long-lived fission products. Much work2–5 has, therefore, been concerned with the possibility of bringing down the strontium-90 uptake by plants through ploughing or through the addition of lime or fertilizer to the soil. Another factor, the effect of ageing on the availability of strontium, has...

  18. Lattice dynamics of strontium tungstate

    Indian Academy of Sciences (India)

    Prabhatasree Goel; R Mittal; S L Chaplot; A K Tyagi

    2008-11-01

    We report here measurements of the phonon density of states and the lattice dynamics calculations of strontium tungstate (SrWO4). At ambient conditions this compound crystallizes to a body-centred tetragonal unit cell (space group I41/a) called scheelite structure. We have developed transferable interatomic potentials to study the lattice dynamics of this class of compounds. The model parameters have been fitted with respect to the experimentally available Raman and infra-red frequencies and the equilibrium unit cell parameters. Inelastic neutron scattering measurements have been carried out in the triple-axis spectrometer at Dhruva reactor. The measured phonon density of states is in good agreement with the theoretical calculations, thus validating the inter-atomic potential developed.

  19. [The Dynamics of the Composition of mtDNA Haplotypes of the Ancient Population of the Altai Mountains from the Early Bronze Age (3rd Millennium BC) to the Iron Age (2nd-1st Centuries BC)].

    Science.gov (United States)

    Gubina, M A; Kulikov, I V; Babenko, V N; Chikisheva, T A; Romaschenko, A G; Voevoda, M I; Molodin, V I

    2016-01-01

    The mtDNA polymorphism in representatives of various archaeological cultures of the Developed Bronze Age, Early Scythian, and Hunnish-Sarmatian periods was analyzed (N = 34). It detected the dominance of Western-Eurasian haplotypes (70.6%) in mtDNA samples from the representatives of the ancient population of the Early Bronze Age--Iron Age on the territory of Altai Mountains. Since the 8th to the 7th centuries BC, a sharp increase was revealed in the Eastern-Eurasian haplogroups A, D, C, andZ (43.75%) as compared to previous cultures (16.7%). The presence of haplotype 223-242-290-319 of haplogroup A8 in Dolgans, Itelmens, Evens, Koryaks, and Yakuts indicates the possible long-term presence of its carriers in areas inhabited by these populations. The prevalence of Western-Eurasian haplotypes is observed not only in the Altai Mountains but also in Central Asia (Kazakhstan) and the South of the Krasnoyarsk Krai. All of the three studied samples from the Western-Eurasian haplogroups were revealed to contain U, H, T, and HV. The ubiquitous presence of haplotypes of haplogroup H and some haplogroups of cluster U (U5al, U4, U2e, and K) in the vast territory from the Yenisei River basin to the Atlantic Ocean may indicate the direction of human settlement, which most likely occurred in the Paleolithic Period from Central Asia.

  20. Vitrification of strontium-90 fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, D.M.; Schulz, W.W.

    1977-04-01

    At Hanford, strontium-90 is removed from high-level nuclear fuel reprocessing waste and converted to strontium-90 fluoride. This /sup 90/SrF/sub 2/ is doubly encapsulated in high-integrity containers which are placed under water in monitored storage pools. Conversion of /sup 90/SrF/sub 2/ to a more immobile compound may be necessary and/or desirable as part of the overall plan for the long-term management of Hanford Defense Wastes. Glasses containing up to 40 mass percent SrF/sub 2/ and having leach rates in the range 1 x 10/sup -8/ to 1 x 10/sup -5/ gram Sr/(m/sup 2/ . s) (1 x 10/sup -7/ to 1 x 10/sup -4/ g Sr/cm/sup 2/ . day)) have now been prepared. From 0.2 to 5 percent of the fluorine is volatilized during the melting of the glass batch at temperatures up to 1500/sup 0/K. At present, the heat generation limit for commercial glasses stored at a nuclear waste repository is 5 kW per canister. All glasses described here would exceed that limit by more than a factor of five. The stored /sup 90/SrF/sub 2/ may be treated separately from the bulk of Hanford waste, in which case it would be diluted to an acceptable power level with inert chemicals in the glass batch. Another option is to blend the /sup 90/SrF/sub 2/ with the bulk of the other Hanford wastes when those wastes are converted to some immobile form.

  1. Cesium and strontium ion specific exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Yates, S.

    1996-10-01

    This work is one of two parallel projects that are part of an ESP task to develop high-capacity, selective, solid extractants for cesium, strontium, and technetium from nuclear wastes. In this subtask, Pacific Northwest National Laboratory (PNNL) is collaborating with AlliedSignal, Inc. (Des Plaines, Illinois) to develop inorganic ion exchangers that are selective for strontium and cesium from alkaline high-level waste and groundwater streams.

  2. Preparation of the Superconductor Substrate: Strontium Titanate

    Science.gov (United States)

    1988-09-01

    single crystals of strontium titanate is derived from the original method developed by Verneuil . 16 The general procedure for the growth of single... crystals growth are reported. The growth direction was determined to be 5 degrees away from the [2111 direction. ICP-emission spectroscopy irdicates... Growth of Strontium Titanate Crystals 5 2.4 Preparation of Substrates 8 3. RESULTS AND CONCLUSIONS 8 REFERENCES 13 Illustrations 1. Schematic Diagram

  3. Co-located 18S/5S rDNA arrays: an ancient and unusual chromosomal trait in Julidini species (Labridae, Perciformes)

    Science.gov (United States)

    Amorim, Karlla Danielle Jorge; Cioffi, Marcelo de Bello; Bertollo, Luiz Antonio Carlos; Soares, Rodrigo Xavier; de Souza, Allyson Santos; da Costa, Gideão Wagner Werneck Felix; Molina, Wagner Franco

    2016-01-01

    Abstract Wrasses (Labridae) are extremely diversified marine fishes, whose species exhibit complex interactions with the reef environment. They are widely distributed in the Indian, Pacific and Atlantic oceans. Their species have displayed a number of karyotypic divergent processes, including chromosomal regions with complex structural organization. Current cytogenetic information for this family is phylogenetically and geographically limited and mainly based on conventional cytogenetic techniques. Here, the distribution patterns of heterochromatin, GC-specific chromosome regions and Ag-NORs, and the organization of 18S and 5S rDNA sites of the Atlantic species Thalassoma noronhanum (Boulenger, 1890), Halichoeres poeyi (Steindachner, 1867), Halichoeres radiatus (Linnaeus, 1758), Halichoeres brasiliensis (Bloch, 1791) and Halichoeres penrosei Starks, 1913, belonging to the tribe Julidini were analyzed. All the species exhibited 2n=48 chromosomes with variation in the number of chromosome arms among genera. Thalassoma noronhanum has 2m+46a, while species of the genus Halichoeres Rüppell, 1835 share karyotypes with 48 acrocentric chromosomes. The Halichoeres species exhibit differences in the heterochromatin distribution patterns and in the number and distribution of 18S and 5S rDNA sites. The occurrence of 18S/5S rDNA syntenic arrangements in all the species indicates a functionally stable and adaptive genomic organization. The phylogenetic sharing of this rDNA organization highlights a marked and unusual chromosomal singularity inside the family Labridae. PMID:28123678

  4. Ancient DNA unravels the truth behind the controversial GUS Greenlandic Norse fur samples: the bison was a horse, and the muskox and beats were goats

    DEFF Research Database (Denmark)

    Sinding, Mikkel-Holger; Arneborg, Jette; Nyegaard, Georg

    2015-01-01

    mitochondrial 16S DNA analysis. The results revealed that the putative bison was, in fact horse, while the bears and muskox were goat. The results demonstrate the importance of using genetic analyses to validate results derived from morphological analyses on hair, in particular where such studies lead...

  5. Ancient DNA of the extinct lava shearwater (Puffinus olsoni from the Canary Islands reveals incipient differentiation within the P. puffinus complex.

    Directory of Open Access Journals (Sweden)

    Oscar Ramirez

    Full Text Available BACKGROUND: The loss of species during the Holocene was, dramatically more important on islands than on continents. Seabirds from islands are very vulnerable to human-induced alterations such as habitat destruction, hunting and exotic predators. For example, in the genus Puffinus (family Procellariidae the extinction of at least five species has been recorded during the Holocene, two of them coming from the Canary Islands. METHODOLOGY/PRINCIPAL FINDINGS: We used bones of the two extinct Canary shearwaters (P. olsoni and P. holeae to obtain genetic data, for use in providing insights into the differentiation process within the genus Puffinus. Although mitochondrial DNA (mtDNA cytochrome b sequences were successfully retrieved from four Holocene specimens of the extinct Lava shearwater (P. olsoni from Fuerteventura (Canary Islands, the P. holeae specimens yielded no DNA. Only one haplotype was detected in P. olsoni, suggesting a low genetic diversity within this species. CONCLUSIONS: The phylogenetic analyses based on the DNA data reveal that: (i the "Puffinus puffinus complex", an assemblage of species defined using osteological characteristics (P. puffinus, P. olsoni, P. mauretanicus, P. yelkouan and probably P. holeae, shows unresolved phylogenetic relationships; (ii despite the differences in body size and proportions, P. olsoni and the extant P. puffinus are sister species. Several hypotheses can be considered to explain the incipient differentiation between P. olsoni and P. puffinus.

  6. Ancient Astronomy in Armenia

    Science.gov (United States)

    Parsamian, Elma S.

    2007-08-01

    The most important discovery, which enriched our knowledge of ancient astronomy in Armenia, was the complex of platforms for astronomical observations on the Small Hill of Metzamor, which may be called an ancient “observatory”. Investigations on that Hill show that the ancient inhabitants of the Armenian Highlands have left us not only pictures of celestial bodies, but a very ancient complex of platforms for observing the sky. Among the ancient monuments in Armenia there is a megalithic monument, probably, being connected with astronomy. 250km South-East of Yerevan there is a structure Zorats Kar (Karahunge) dating back to II millennium B.C. Vertical megaliths many of which are more than two meters high form stone rings resembling ancient stone monuments - henges in Great Britain and Brittany. Medieval observations of comets and novas by data in ancient Armenian manuscripts are found. In the collection of ancient Armenian manuscripts (Matenadaran) in Yerevan there are many manuscripts with information about observations of astronomical events as: solar and lunar eclipses, comets and novas, bolides and meteorites etc. in medieval Armenia.

  7. Ancient DNA analysis of mid-holocene individuals from the Northwest Coast of North America reveals different evolutionary paths for mitogenomes.

    Directory of Open Access Journals (Sweden)

    Yinqiu Cui

    Full Text Available To gain a better understanding of North American population history, complete mitochondrial genomes (mitogenomes were generated from four ancient and three living individuals of the northern Northwest Coast of North America, specifically the north coast of British Columbia, Canada, current home to the indigenous Tsimshian, Haida, and Nisga'a. The mitogenomes of all individuals were previously unknown and assigned to new sub-haplogroup designations D4h3a7, A2ag and A2ah. The analysis of mitogenomes allows for more detailed analyses of presumed ancestor-descendant relationships than sequencing only the HVSI region of the mitochondrial genome, a more traditional approach in local population studies. The results of this study provide contrasting examples of the evolution of Native American mitogenomes. Those belonging to sub-haplogroups A2ag and A2ah exhibit temporal continuity in this region for 5000 years up until the present day. Of possible associative significance is that archaeologically identified house structures in this region maintain similar characteristics for this same period of time, demonstrating cultural continuity in residence patterns. The individual dated to 6000 years before present (BP exhibited a mitogenome belonging to sub-haplogroup D4h3a. This sub-haplogroup was earlier identified in the same general area at 10300 years BP on Prince of Wales Island, Alaska, and may have gone extinct, as it has not been observed in any living individuals of the Northwest Coast. The presented case studies demonstrate the different evolutionary paths of mitogenomes over time on the Northwest Coast.

  8. Ancient DNA from hunter-gatherer and farmer groups from Northern Spain supports a random dispersion model for the Neolithic expansion into Europe.

    Directory of Open Access Journals (Sweden)

    Montserrat Hervella

    Full Text Available BACKGROUND/PRINCIPAL FINDINGS: The phenomenon of Neolithisation refers to the transition of prehistoric populations from a hunter-gatherer to an agro-pastoralist lifestyle. Traditionally, the spread of an agro-pastoralist economy into Europe has been framed within a dichotomy based either on an acculturation phenomenon or on a demic diffusion. However, the nature and speed of this transition is a matter of continuing scientific debate in archaeology, anthropology, and human population genetics. In the present study, we have analyzed the mitochondrial DNA diversity in hunter-gatherers and first farmers from Northern Spain, in relation to the debate surrounding the phenomenon of Neolithisation in Europe. METHODOLOGY/SIGNIFICANCE: Analysis of mitochondrial DNA was carried out on 54 individuals from Upper Paleolithic and Early Neolithic, which were recovered from nine archaeological sites from Northern Spain (Basque Country, Navarre and Cantabria. In addition, to take all necessary precautions to avoid contamination, different authentication criteria were applied in this study, including: DNA quantification, cloning, duplication (51% of the samples and replication of the results (43% of the samples by two independent laboratories. Statistical and multivariate analyses of the mitochondrial variability suggest that the genetic influence of Neolithisation did not spread uniformly throughout Europe, producing heterogeneous genetic consequences in different geographical regions, rejecting the traditional models that explain the Neolithisation in Europe. CONCLUSION: The differences detected in the mitochondrial DNA lineages of Neolithic groups studied so far (including these ones of this study suggest different genetic impact of Neolithic in Central Europe, Mediterranean Europe and the Cantabrian fringe. The genetic data obtained in this study provide support for a random dispersion model for Neolithic farmers. This random dispersion had a different

  9. Human evolution: a tale from ancient genomes.

    Science.gov (United States)

    Llamas, Bastien; Willerslev, Eske; Orlando, Ludovic

    2017-02-05

    The field of human ancient DNA (aDNA) has moved from mitochondrial sequencing that suffered from contamination and provided limited biological insights, to become a fully genomic discipline that is changing our conception of human history. Recent successes include the sequencing of extinct hominins, and true population genomic studies of Bronze Age populations. Among the emerging areas of aDNA research, the analysis of past epigenomes is set to provide more new insights into human adaptation and disease susceptibility through time. Starting as a mere curiosity, ancient human genetics has become a major player in the understanding of our evolutionary history.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.

  10. Putative ancient microorganisms from amber nuggets.

    Science.gov (United States)

    Veiga-Crespo, Patricia; Blasco, Lucía; Poza, Margarita; Villa, Tomás G

    2007-06-01

    Evolutionary microbiology studies based on the isolation of ancient DNA and/or microbial samples are scarce due to the difficulty of finding well preserved biological specimens. However, amber is a fossil resin with natural preserving properties for microbial cells and DNA. The visualization by transmission electron microscopy of different microorganism-like specimens found in amber nuggets from both the Miocene and the Cretaceous periods was accompanied by studies of ancient DNA obtained from the nuggets. After the design of specific primers based on the present sequences of both genes in Saccharomyces cerevisiae, the ancestral AGP2 sequence from the Miocene, as well as the 18S rRNA from the Cretaceous, were amplified.

  11. Genetic diversity among ancient Nordic populations.

    Directory of Open Access Journals (Sweden)

    Linea Melchior

    Full Text Available Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13% than among extant Danes and Scandinavians (approximately 2.5% as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  12. Solubility of strontium-substituted apatite by solid titration

    OpenAIRE

    Pan, HB; Darvell, BW; Luk, KDK; Lu, WW; Li, ZY; Lam, WM; Wong, JC

    2009-01-01

    Solid titration was used to explore the solubility isotherms of partially (Srx-HAp, x = 1, 5, 10, 40, 60 mol.%) and fully substituted strontium hydroxyapatite (Sr-HAp). Solubility increased with increasing strontium content. No phase other than strontium-substituted HAp, corresponding to the original titrant, was detected in the solid present at equilibrium; in particular, dicalcium hydrogen phosphate was not detected at low pH. The increase in solubility with strontium content is interpreted...

  13. An ancient satellite DNA has maintained repetitive units of the original structure in most species of the living fossil plant genus Zamia.

    Science.gov (United States)

    Cafasso, Donata; Chinali, Gianni

    2014-03-01

    ZpS1 satellite DNA is specific to the genus Zamia and presents repetitive units organized as long arrays and also as very short arrays dispersed in the genome. We have characterized the structure of the ZpS1 repeats in 12 species representative of the whole geographic distribution of the genus. In most species, the clone most common sequences (cMCS) were so similar that a general most common sequence (GMCS) of the ZpS1 repetitive unit in the genus could be obtained. The few partial variations from the GMCS found in cMCS of some species correspond to variable positions present in most other species, as indicated by the clone consensus sequences (cCS). Two species have an additional species-specific variety of ZpS1 satellite. The dispersed repeats were found to contain more mutations than repeats from long arrays. Our results indicate that all or most species of Zamia inherited the ZpS1 satellite from a common ancestor in Miocene and have maintained repetitive units of the original structure till present. The features of ZpS1 satellite in the genus Zamia are poorly compatible with the model of concerted evolution, but they are perfectly consistent with a new model of satellite evolution based on experimental evidences indicating that a specific amplification-substitution repair mechanism maintains the homogeneity and stability of the repeats structure in each satellite DNA originally present in a species as long as the species exists.

  14. Specific activity and isotope abundances of strontium in purified strontium-82

    Energy Technology Data Exchange (ETDEWEB)

    Fitzsimmons, J. M.; Medvedev, D. G.; Mausner, L. F.

    2015-11-12

    A linear accelerator was used to irradiate a rubidium chloride target with protons to produce strontium-82 (Sr-82), and the Sr-82 was purified by ion exchange chromatography. The amount of strontium associated with the purified Sr-82 was determined by either: ICP-OES or method B which consisted of a summation of strontium quantified by gamma spectroscopy and ICP-MS. The summation method agreed within 10% to the ICP-OES for the total mass of strontium and the subsequent specific activities were determined to be 0.25–0.52 TBq mg-1. Method B was used to determine the isotope abundances by weight% of the purified Sr-82, and the abundances were: Sr-82 (10–20.7%), Sr-83 (0–0.05%), Sr-84 (35–48.5%), Sr-85 (16–25%), Sr-86 (12.5–23%), Sr-87 (0%), and Sr-88 (0–10%). The purified strontium contained mass amounts of Sr-82, Sr-84, Sr-85, Sr-86, and Sr-88 in abundances not associated with natural abundance, and 90% of the strontium was produced by the proton irradiation. A comparison of ICP-OES and method B for the analysis of Sr-82 indicated analysis by ICP-OES would be easier to determine total mass of strontium and comply with regulatory requirements. An ICP-OES analytical method for Sr-82 analysis was established and validated according to regulatory guidelines.

  15. Ancient Marital Rites

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Clearly defined rites governing speech and actions dominated both the social and domestic activities of ancient Chinese people. Rites not only dominated the lives of men, but were also prominent in the lives of women.

  16. Ancient Chinese Architecture

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    CHINESE people have accu-mulated a great deal ofexperience in architecture,constantly improving building ma-terials and thus creating uniquebuilding styles.The history of ancient Chinesearchitechtural development can be

  17. Strontium Ions Substitution in Brushite Crystals: The Role of Strontium Chloride

    OpenAIRE

    2011-01-01

    The incorporation of strontium chloride to brushite cement was successful to introduce strontium ions within the lattice of brushite crystals. The effect of strontium ions on brushite cement properties was concentration dependent; such that, the addition of 5% and 10% (w/w) SrCl2 significantly increased the cement FST and the addition of 10% SrCl2 decreased the cement tensile strength. Further, cement weight loss was shown to be increased by cement modification with SrCl2. The combination of ...

  18. Enhanced Magnetic Trap Loading for Atomic Strontium

    CERN Document Server

    Barker, D S; Pisenti, N C; Campbell, G K

    2015-01-01

    We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a Magneto-Optical Trap (MOT). This is achieved by adding a depumping laser tuned to the 3P1 to 3S1 (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65 % for the bosonic isotopes and up to 30 % for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, intensity, and beam size. To understand the results, we develop a one-dimensional rate equation model of the system, which is in good agreement with the data. We discuss the use of other transitions in strontium for accelerated trap loading and the application of the technique to other alkaline-earth-like atoms.

  19. Enhanced magnetic trap loading for atomic strontium

    Science.gov (United States)

    Barker, D. S.; Reschovsky, B. J.; Pisenti, N. C.; Campbell, G. K.

    2015-10-01

    We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a magneto-optical trap. This is achieved by adding a depumping laser tuned to the P31→S31 (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65% for the bosonic isotopes and up to 30% for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, intensity, and beam size. To understand the results, we develop a one-dimensional rate equation model of the system, which is in good agreement with the data. We discuss the use of other transitions in strontium for accelerated trap loading and the application of the technique to other alkaline-earth-like atoms.

  20. Printed Barium Strontium Titanate capacitors on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Sette, Daniele [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg); Kovacova, Veronika [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Defay, Emmanuel, E-mail: emmanuel.defay@list.lu [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg)

    2015-08-31

    In this paper, we show that Barium Strontium Titanate (BST) films can be prepared by inkjet printing of sol–gel precursors on platinized silicon substrate. Moreover, a functional variable capacitor working in the GHz range has been made without any lithography or etching steps. Finally, this technology requires 40 times less precursors than the standard sol–gel spin-coating technique. - Highlights: • Inkjet printing of Barium Strontium Titanate films • Deposition on silicon substrate • Inkjet printed silver top electrode • First ever BST films thinner than 1 μm RF functional variable capacitor that has required no lithography.

  1. Enhanced Magnetic Trap Loading for Atomic Strontium

    OpenAIRE

    Barker, D.S.; Reschovsky, B. J.; Pisenti, N. C.; Campbell, G. K.

    2015-01-01

    We report on a technique to improve the continuous loading of atomic strontium into a magnetic trap from a Magneto-Optical Trap (MOT). This is achieved by adding a depumping laser tuned to the 3P1 to 3S1 (688-nm) transition. The depumping laser increases atom number in the magnetic trap and subsequent cooling stages by up to 65 % for the bosonic isotopes and up to 30 % for the fermionic isotope of strontium. We optimize this trap loading strategy with respect to the 688-nm laser detuning, int...

  2. First principles investigation of substituted strontium hexaferrite

    Science.gov (United States)

    Dixit, Vivek

    This dissertation investigates how the magnetic properties of strontium hexaferrite change upon the substitution of foreign atoms at the Fe sites. Strontium hexaferrite, SrFe12O19, is a commonly used hard magnetic material and is produced in large quantities (around 500,000 tons per year). For different applications of strontium hexaferrite, its magnetic properties can be tuned by a proper substitution of the foreign atoms. Experimental screening for a proper substitution is a cost-intensive and time-consuming process, whereas computationally it can be done more efficiently. We used the 'density functional theory' a first principles based method to study substituted strontium hexaferrite. The site occupancies of the substituted atoms were estimated by calculating the substitution energies of different configurations. The formation probabilities of configurations were used to calculate the magnetic properties of substituted strontium hexaferrite. In the first study, Al-substituted strontium hexaferrite, SrFe12-x AlxO19 with x=0.5 and x=1.0 were investigated. It was found that at the annealing temperature the non-magnetic Al +3 ions preferentially replace Fe+3 ions from the 12 k and 2a sites. We found that the magnetization decreases and the magnetic anisotropy field increases as the fraction, x of the Al atoms increases. In the second study, SrFe12-xGaxO19 and SrFe12-xInxO19 with x=0.5 and x=1.0 were investigated. In the case of SrFe12-xGaxO19, the sites where Ga+3 ions prefer to enter are: 12 k, 2a, and 4f1. For SrFe12-xInxO19, In+3 ions most likely to occupy the 12k, 4f1 , and 4f2 sites. In both cases the magnetization was found to decrease slightly as the fraction of substituted atom increases. The magnetic anisotropy field increased for SrFe12-xGaxO 19, and decreased for SrFe12-xInxO19 as the concentration of substituted atoms increased. In the third study, 23 elements (M) were screened for their possible substitution in strontium hexaferrite, SrFe12-xMxO 19

  3. Dendritic network models: Improving isoscapes and quantifying influence of landscape and in-stream processes on strontium isotopes in rivers

    Science.gov (United States)

    Brennan, Sean R.; Torgersen, Christian E.; Hollenbeck, Jeff P.; Fernandez, Diego P.; Jensen, Carrie K.; Schindler, Daniel E.

    2016-05-01

    A critical challenge for the Earth sciences is to trace the transport and flux of matter within and among aquatic, terrestrial, and atmospheric systems. Robust descriptions of isotopic patterns across space and time, called "isoscapes," form the basis of a rapidly growing and wide-ranging body of research aimed at quantifying connectivity within and among Earth's systems. However, isoscapes of rivers have been limited by conventional Euclidean approaches in geostatistics and the lack of a quantitative framework to apportion the influence of processes driven by landscape features versus in-stream phenomena. Here we demonstrate how dendritic network models substantially improve the accuracy of isoscapes of strontium isotopes and partition the influence of hydrologic transport versus local geologic features on strontium isotope ratios in a large Alaska river. This work illustrates the analytical power of dendritic network models for the field of isotope biogeochemistry, particularly for provenance studies of modern and ancient animals.

  4. Dendritic network models: Improving isoscapes and quantifying influence of landscape and in-stream processes on strontium isotopes in rivers

    Science.gov (United States)

    Brennan, Sean R.; Torgersen, Christian; Hollenbeck, Jeff P.; Fernandez, Diego P.; Jensen, Carrie K; Schindler, Daniel E.

    2016-01-01

    A critical challenge for the Earth sciences is to trace the transport and flux of matter within and among aquatic, terrestrial, and atmospheric systems. Robust descriptions of isotopic patterns across space and time, called “isoscapes,” form the basis of a rapidly growing and wide-ranging body of research aimed at quantifying connectivity within and among Earth's systems. However, isoscapes of rivers have been limited by conventional Euclidean approaches in geostatistics and the lack of a quantitative framework to apportion the influence of processes driven by landscape features versus in-stream phenomena. Here we demonstrate how dendritic network models substantially improve the accuracy of isoscapes of strontium isotopes and partition the influence of hydrologic transport versus local geologic features on strontium isotope ratios in a large Alaska river. This work illustrates the analytical power of dendritic network models for the field of isotope biogeochemistry, particularly for provenance studies of modern and ancient animals.

  5. Source of Lake Vostok Cations Constrained with Strontium Isotopes

    Science.gov (United States)

    Lyons, William; Welch, Kathleen; Priscu, John; Tranter, Martyn; Royston-Bishop, George

    2016-08-01

    Lake Vostok is the largest sub-glacial lake in Antarctica. The primary source of our current knowledge regarding the geochemistry and biology of the lake comes from the analysis of refrozen lake water associated with ice core drilling. Several sources of dissolved ions and particulate matter to the lake have been proposed, including materials from the melted glacier ice, the weathering of underlying geological materials, hydrothermal activity and underlying, ancient evaporitic deposits. A sample of Lake Vostok Type 1 accretion ice has been analyzed for its 87Sr/86Sr signature as well as its major cation and anion and Sr concentrations. The strontium isotope ratio of 0.71655 and the Ca/Sr ratio in the sample strongly indicate that the major source of the Sr is from aluminosilicate minerals from the continental crust. These data imply that at least a portion of the other cations in the Type 1 ice also are derived from continental crustal materials and not hydrothermal activity, the melted glacier ice, or evaporitic sources.

  6. Calcium and Strontium in Swedish Waters and Fish, and Accumulation of Strontium-90

    Energy Technology Data Exchange (ETDEWEB)

    Agnedal, P.O.

    1966-04-15

    The purpose of this study has been to investigate the correlation between calcium and strontium in fish in relation to the concentration of these elements in the water. An investigation of the uptake of strontium-90 has also been made and permissible levels of strontium-90 in the water is calculated based upon the uptake in fish muscle tissues. Lakes with calcium concentrations between 2 - 63 mg/l have been studied and samples from the Baltic coastal water are also included. Three fish species are studied, viz. pike (Esox lucius (L.)), perch (Perca fluviatilis (L.)) and roach (Leuciscus rutilus (L.)). Bones, muscle tissues and skin + scales have been analysed. Strontium-90 measurements have been made showing an increase in both water and fish. Calculations show that in water with about 2 mg Ca/l a 10-fold increase of the existing strontium-90 level might give strontium-90 concentrations in fish muscle tissues close to what is permissible. In lakes with calcium concentrations 20 - 40 mg/l the permissible levels for drinking water will be exceeded before the fish consumption would have to be restricted.

  7. Cesium and Strontium Separation Technologies Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    T. A. Todd; T. A. Todd; J. D. Law; R. S. Herbst

    2004-03-01

    Integral to the Advanced Fuel Cycle Initiative (AFCI) Program’s proposed closed nuclear fuel cycle, the fission products cesium and strontium in the dissolved spent nuclear fuel stream are to be separated and managed separately. A comprehensive literature survey is presented to identify cesium and strontium separation technologies that have the highest potential and to focus research and development efforts on these technologies. Removal of these high-heat-emitting fission products reduces the radiation fields in subsequent fuel cycle reprocessing streams and provides a significant short-term (100 yr) heat source reduction in the repository. This, along with separation of actinides, may provide a substantial future improvement in the amount of fuel that could be stored in a geologic repository. The survey and review of the candidate cesium and strontium separation technologies are presented herein. Because the AFCI program intends to manage cesium and strontium together, technologies that simultaneously separate both elements are of the greatest interest, relative to technologies that separate only one of the two elements.

  8. Dentistry in ancient mesopotamia.

    Science.gov (United States)

    Neiburger, E J

    2000-01-01

    Sumer, an empire in ancient Mesopotamia (southern Iraq), is well known as the cradle of our modern civilization and the home of biblical Abraham. An analysis of skeletal remains from cemeteries at the ancient cities of Ur and Kish (circa 2000 B.C.), show a genetically homogeneous, diseased, and short-lived population. These ancient Mesopotamians suffered severe dental attrition (95 percent), periodontal disease (42 percent), and caries (2 percent). Many oral congenital and neoplastic lesions were noted. During this period, the "local dentists" knew only a few modern dental techniques. Skeletal (dental) evidence indicates that the population suffered from chronic malnutrition. Malnutrition was probably caused by famine, which is substantiated in historic cuneiform and biblical writings, geologic strata samples, and analysis of skeletal and forensic dental pathology. These people had modern dentition but relatively poor dental health. The population's lack of malocclusions, caries, and TMJ problems appear to be due to flat plane occlusion.

  9. Dwarfs in ancient Egypt.

    Science.gov (United States)

    Kozma, Chahira

    2006-02-15

    Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities.

  10. Creative Ventures: Ancient Civilizations.

    Science.gov (United States)

    Stark, Rebecca

    The open-ended activities in this book are designed to extend the imagination and creativity of students and encourage students to examine their feelings and values about historic eras. Civilizations addressed include ancient Egypt, Greece, Rome, Mayan, Stonehenge, and Mesopotamia. The activities focus upon the cognitive and affective pupil…

  11. Ancient Egypt: Personal Perspectives.

    Science.gov (United States)

    Wolinski, Arelene

    This teacher resource book provides information on ancient Egypt via short essays, photographs, maps, charts, and drawings. Egyptian social and religious life, including writing, art, architecture, and even the practice of mummification, is conveniently summarized for the teacher or other practitioner in a series of one to three page articles with…

  12. Cloning Ancient Trees

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    west of Tiananmen Square in Beijing, in Zhongshan Park, there stand several ancient cypress trees, each more than 1,000 years old. Their leafy crowns are all more than 20 meters high, while four have trunks that are 6 meters in circumference. The most unique of these

  13. Ancient ports of Kalinga

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.

    The ancient Kingdom of Kalinga mentioned in the Hathigumpha inscription of Kharavela (1st century B.C.) extended from the mouths of the Ganges to the estuary of Godavari river on the East Coast. Ptolemy (100 A.D.) mentions that Paluru (District...

  14. Ancient deforestation revisited.

    Science.gov (United States)

    Hughes, J Donald

    2011-01-01

    The image of the classical Mediterranean environment of the Greeks and Romans had a formative influence on the art, literature, and historical perception of modern Europe and America. How closely does is this image congruent with the ancient environment as it in reality existed? In particular, how forested was the ancient Mediterranean world, was there deforestation, and if so, what were its effects? The consensus of historians, geographers, and other scholars from the mid-nineteenth century through the first three quarters of the twentieth century was that human activities had depleted the forests to a major extent and caused severe erosion. My research confirmed this general picture. Since then, revisionist historians have questioned these conclusions, maintaining instead that little environmental damage was done to forests and soils in ancient Greco-Roman times. In a reconsideration of the question, this paper looks at recent scientific work providing proxy evidence for the condition of forests at various times in ancient history. I look at three scientific methodologies, namely anthracology, palynology, and computer modeling. Each of these avenues of research offers support for the concept of forest change, both in abundance and species composition, and episodes of deforestation and erosion, and confirms my earlier work.

  15. Printing Ancient Terracotta Warriors

    Science.gov (United States)

    Gadecki, Victoria L.

    2010-01-01

    Standing in awe in Xian, China, at the Terra Cotta warrior archaeological site, the author thought of sharing this experience and excitement with her sixth-grade students. She decided to let her students carve patterns of the ancient soldiers to understand their place in Chinese history. They would make block prints and print multiple soldiers on…

  16. Strontium isotope stratigraphy of the Pelotas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Zerfass, Geise de Santana dos Anjos, E-mail: geise.zerfass@petrobras.com.br [Petroleo Brasileiro S.A. (PETROBRAS/CENPES/PDGEO/BPA), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento Leopoldo Americo Miguez de Mello; Chemale Junior, Farid, E-mail: fchemale@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias; Moura, Candido Augusto Veloso, E-mail: candido@ufpa.br [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Geociencias. Dept. de Geoquimica e Petrologia; Costa, Karen Badaraco, E-mail: karen.costa@usp.br [Instituto Oceanografico, Sao Paulo, SP (Brazil); Kawashita, Koji, E-mail: koji@usp.br [Unversidade de Sao Paulo (USP), SP (Brazil). Centro de Pesquisas Geocronologicas

    2014-07-01

    Strontium isotope data were obtained from foraminifera shells of the Pelotas Basin Tertiary deposits to facilitate the refinement of the chronostratigraphic framework of this section. This represents the first approach to the acquisition of numerical ages for these strata. Strontium isotope stratigraphy allowed the identification of eight depositional hiatuses in the Eocene-Pliocene section, here classified as disconformities and a condensed section. The reconnaissance of depositional gaps based on confident age assignments represents an important advance considering the remarkably low chronostratigraphic resolution in the Cenozoic section of the Pelotas Basin. The recognition of hiatuses that match hiatuses is based on biostratigraphic data, as well as on global events. Furthermore, a substantial increase in the sedimentation rate of the upper Miocene section was identified. Paleotemperature and productivity trends were identified based on oxygen and carbon isotope data from the Oligocene-Miocene section, which are coherent with worldwide events, indicating the environmental conditions during sedimentation. (author)

  17. Phase Stability of the Lanthanum Strontium Manganites

    Science.gov (United States)

    Zheng, Feng; Pederson, Larry

    1996-03-01

    Phase diagram and thermodynamic data of the La-Sr-Mn-O system has been studied. The ABO3 -type perovskite of this system is presently the preferred cathode material for application in solid oxide fuel cells. And the phase stability of the lanthanum strontium manganites at elevated temperature is vital to fuel cell operation. Measuring the electromotive force through solid galvanic cell (-) Air,Pt|SrF_2,SrO||CaF_2||La_1-xSr_xMnO_3,SrF_2|Pt,Air (+) and the like enable us to derive the strontium oxide activity and other thermodynamic parameters such as Gibbs free energy of reaction, etc, which help us to understand the materials in using.

  18. Lanthanide doped strontium-barium cesium halide scintillators

    Science.gov (United States)

    Bizarri, Gregory; Bourret-Courchesne, Edith; Derenzo, Stephen E.; Borade, Ramesh B.; Gundiah, Gautam; Yan, Zewu; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew

    2015-06-09

    The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

  19. Growth and characterization of strontium tartrate pentahydrate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Firdous, A.; Ahmad, M.M. [Department of Physics, National Institute of Technology, Kashmir (India); Quasim, I.; Kotru, P.N. [Crystal Growth and Materials Research Laboratory, Department of Physics and Electronics, University of Jammu (India)

    2008-10-15

    Silica gel impregnated with L-tartaric acid and using strontium nitrate as the second reactant leads to the growth of well faceted strontium tartrate pentahydrate single crystals.The morphological developmen and internal cell dimensions are observed to be different from the ones reported in the literature for strontium tartrate trihydrate crystals. The crystals are characterized using XRD, CH analysis, SEM, FTIR spectroscopy and thermoanalytical techniques. The crystals are observed to be thermally stable upto about 105 C but thereafter start decomposing and ejecting water of hydration at various stages, finally reducing to strontium oxide. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Strontium ranelate in postmenopausal osteoporosis treatment: a critical appraisal

    Directory of Open Access Journals (Sweden)

    Roberto Cesareo

    2009-12-01

    Full Text Available Roberto Cesareo1, Clemente Napolitano1, Mario Iozzino21Department of Internal Medicine, 2Department of Radiology, S.M. Goretti Hospital, Latina, ItalyAbstract: Osteoporosis is a progressive and debilitating disease characterized by a massive bone loss with a deterioration of bone tissues, and a propensity for a fragility fracture. Strontium ranelate is the first antiosteoporotic treatment that has dual mode of action and simultaneously increases bone formation, while decreasing bone resorption, thus rebalancing bone turnover formation. Strontium ranelate rebalances bone turnover in favor of improved bone geometry, cortical thickness, trabecular bone morphology and intrinsic bone tissue quality, which translates into enhanced bone strength. This review describes the mechanism of the strontium ranelate action and its effects on bone mineral density, bone turnover, and osteoporotic fractures. The efficacy of strontium ranelate in postmenopausal osteoporosis treatment to reduce the risk of vertebral and hip fractures has been highlighted in several randomized, controlled trials. Treatment efficacy with strontium ranelate has been documented across a wide range of patient profiles: age, number of prevalent vertebral fractures, body mass index, and a family history of osteoporosis. Because strontium ranelate has a large spectrum of efficacy, it can be used to treat different subgroups of patients with postmenopausal osteoporosis. Strontium ranelate was shown to be relatively well tolerated and the safety aspects were good. Strontium ranelate should be considered as a first-line treatment for postmenopausal osteoporotic patients.Keywords: osteoporosis, strontium ranelate, therapy

  1. Synthesis of Strontium Carbonate by the Induction of Microbiology

    Institute of Scientific and Technical Information of China (English)

    HUO Ji-Chuan; LIU Shu-Xin; WANG Li-Na; LEI Hong

    2012-01-01

    Spherical strontium carbonate was synthesized by the induction of microbial bacillus pasteurii at ambient temperature with strontium chloride and urea as the raw materials. The phase composition, particle size and morphology of the product were studied by XRD and SEM. The results indicated that the strontium carbonate synthesized by the induction of microbial bacillus pasteurii was of good dispersion and uniform particle size. The spherical strontium carbonate particles obtained by adding different control agents were constructed by numerous flakes or olive-shaped nano-particles. The products were orthorhombic according to their XRD patterns.

  2. Ceria and strontium titanate based electrodes

    DEFF Research Database (Denmark)

    2010-01-01

    A ceramic anode structure obtainable by a process comprising the steps of: (a) providing a slurry by dispersing a powder of an electronically conductive phase and by adding a binder to the dispersion, in which said powder is selected from the group consisting of niobium-doped strontium titanate, ......) with the precursor solution of step (c),(e) subjecting the resulting structure of step (d) to calcination, and (f) conducting steps (d)-(e) at least once....

  3. Eu2+ luminescence in strontium aluminates

    NARCIS (Netherlands)

    Dutczak, D.; Juestel, T.; Ronda, C.; Meijerink, A.

    2015-01-01

    The luminescence properties of Eu2+ doped strontium aluminates are reported and reviewed for a variety of aluminates, viz. SrAl12O19, SrAl4O7, Sr4Al14O25, SrAl2O4 and Sr3Al2O6. The aim of the research is to investigate the role of local coordination and covalency of the aluminate host lattice, relat

  4. Ancient human microbiomes.

    Science.gov (United States)

    Warinner, Christina; Speller, Camilla; Collins, Matthew J; Lewis, Cecil M

    2015-02-01

    Very recently, we discovered a vast new microbial self: the human microbiome. Our native microbiota interface with our biology and culture to influence our health, behavior, and quality of life, and yet we know very little about their origin, evolution, or ecology. With the advent of industrialization, globalization, and modern sanitation, it is intuitive that we have changed our relationship with microbes, but we have little information about the ancestral state of our microbiome, and we therefore lack a foundation for characterizing this change. High-throughput sequencing has opened up new opportunities in the field of paleomicrobiology, allowing us to investigate the evolution of the complex microbial ecologies that inhabit our bodies. By focusing on recent coprolite and dental calculus research, we explore how emerging research on ancient human microbiomes is changing the way we think about ancient disease and how archaeological studies can contribute to a medical understanding of health and nutrition today.

  5. Comets in ancient India

    CERN Document Server

    Gupta, Patrick Das

    2014-01-01

    The Indo-aryans of ancient India observed stars and constellations for ascertaining auspicious times for sacrificial rites ordained by vedas. It is but natural that they would have recounted in the vedic texts about comets. In Rigveda ($\\sim $ 1700 - 1500 BC) and Atharvaveda ($\\sim $ 1150 BC), there are references to dhumaketus and ketus, which stand for comets in Sanskrit. Varahamihira in 550 AD and Ballala Sena ($\\sim $ 1100 - 1200 AD) have described a large number of comets recorded by ancient seers such as Parashara, Vriddha Garga, Narada, Garga, etc. In this article, I conjecture that an episode narrated in Mahabharata of a radiant king, Nahusha, ruling the heavens, and later turning into a serpent after he had kicked the seer Agastya (also the star Canopus), is a mythological retelling of a cometary event.

  6. Deep sequencing of RNA from ancient maize kernels.

    Directory of Open Access Journals (Sweden)

    Sarah L Fordyce

    Full Text Available The characterization of biomolecules from ancient samples can shed otherwise unobtainable insights into the past. Despite the fundamental role of transcriptomal change in evolution, the potential of ancient RNA remains unexploited - perhaps due to dogma associated with the fragility of RNA. We hypothesize that seeds offer a plausible refuge for long-term RNA survival, due to the fundamental role of RNA during seed germination. Using RNA-Seq on cDNA synthesized from nucleic acid extracts, we validate this hypothesis through demonstration of partial transcriptomal recovery from two sources of ancient maize kernels. The results suggest that ancient seed transcriptomics may offer a powerful new tool with which to study plant domestication.

  7. Deep Sequencing of RNA from Ancient Maize Kernels

    Science.gov (United States)

    Rasmussen, Morten; Cappellini, Enrico; Romero-Navarro, J. Alberto; Wales, Nathan; Alquezar-Planas, David E.; Penfield, Steven; Brown, Terence A.; Vielle-Calzada, Jean-Philippe; Montiel, Rafael; Jørgensen, Tina; Odegaard, Nancy; Jacobs, Michael; Arriaza, Bernardo; Higham, Thomas F. G.; Ramsey, Christopher Bronk; Willerslev, Eske; Gilbert, M. Thomas P.

    2013-01-01

    The characterization of biomolecules from ancient samples can shed otherwise unobtainable insights into the past. Despite the fundamental role of transcriptomal change in evolution, the potential of ancient RNA remains unexploited – perhaps due to dogma associated with the fragility of RNA. We hypothesize that seeds offer a plausible refuge for long-term RNA survival, due to the fundamental role of RNA during seed germination. Using RNA-Seq on cDNA synthesized from nucleic acid extracts, we validate this hypothesis through demonstration of partial transcriptomal recovery from two sources of ancient maize kernels. The results suggest that ancient seed transcriptomics may offer a powerful new tool with which to study plant domestication. PMID:23326310

  8. Ambrosia of Ancients

    Institute of Scientific and Technical Information of China (English)

    HUOJIANYING

    2004-01-01

    IN 196 B.C. a Chinese philosopher observedto his ruler: "A lord's to ppriority is the welfare of his subjects; to the peopie, eating is foremost." Chinese ancients perceived clearly the essentiality of grain cultivation to the survival of the population and country as a whole. This is apparent in the premillennial term for "country" -sheji literally translated as god of land and grain.

  9. Incorporation of strontium up to 5 Mol. (% to hydroxyapatite did not affect its cytocompatibility

    Directory of Open Access Journals (Sweden)

    Débora dos Santos Tavares

    2011-12-01

    Full Text Available The aim of this work was to produce hydroxyapatite (HA granules containing 0, 0.5, 1 and 5 mol. (% of strontium (Sr, evaluate the physico-chemical properties and also the cytotoxicity by three different parameters of cell viability (ISO 10993-5, 10993-12. The physico-chemical characterization was carried out by using X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FTIR and X-ray fluorescence (XRF. The XRD profile presented the main peaks of HA (JCPDS 860740 and the absorption bands of HA were identified by FTIR. The XRF results showed that the strontium concentration was close to the theoretical value. Regarding the cytotoxicity assays, the incorporation of strontium up to 5 mol. (% to the HA did not affected dehydrogenase activity (XTT, 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide, membrane integrity (neutral red uptake or DNA contend (incorporation of crystal violet, in relation to HA alone. In conclusion, hydroxyapatite containing from 0.5 to 5 mol. (% of Sr was successfully produced and presented no cytotoxicity.

  10. Suicide in ancient Greece.

    Science.gov (United States)

    Laios, K; Tsoukalas, G; Kontaxaki, M-I; Karamanou, M; Androutsos, G

    2014-01-01

    The theme of suicide appears several times in ancient Greek literature. However, each such reference acquires special significance depending on the field from which it originates. Most of the information found in mythology, but the suicide in a mythological tale, although in terms of motivation and mental situation of heroes may be in imitation of similar incidents of real life, in fact is linked with the principles of the ancient Greek religion. In ancient drama and mainly in tragedies suicide conduces to the tragic hypostasis of the heroes and to the evolution of the plot and also is a tool in order to be presented the ideas of poets for the relations of the gods, the relation among gods and men and the relation among the men. In ancient Greek philosophy there were the deniers of suicide, who were more concerned about the impact of suicide on society and also these who accepted it, recognizing the right of the individual to put an end to his life, in order to avoid personal misfortunes. Real suicides will be found mostly from historical sources, but most of them concern leading figures of the ancient world. Closer to the problem of suicide in the everyday life of antiquity are ancient Greek medicines, who studied the phenomenon more general without references to specific incidents. Doctors did not approve in principal the suicide and dealt with it as insane behavior in the development of the mental diseases, of melancholia and mania. They considered that the discrepancy of humors in the organ of logic in the human body will cause malfunction, which will lead to the absurdity and consequently to suicide, either due to excessive concentration of black bile in melancholia or due to yellow bile in mania. They believed that greater risk to commit suicide had women, young people and the elderly. As therapy they used the drugs of their time with the intention to induce calm and repression in the ill person, therefore they mainly used mandragora. In general, we would say

  11. STRONTIUM AS AN EFFICIENT PROMOTER FOR SUPPORTED PALLADIUM HYDROGENATION CATALYSTS

    Science.gov (United States)

    The effect of strontium promotion is studied for a series of supported palladium catalysts such as Pd/zeolite-β, Pd/Al2O3, Pd/SiO2, Pd/hydrotalcite and Pd/MgO. Strontium is found to be an effective promoter for enhancing the metal area, perce...

  12. Age and gender specific biokinetic model for strontium in humans

    Energy Technology Data Exchange (ETDEWEB)

    Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2015-03-01

    A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitation for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic model for strontium (Sr-AGe model). The Sr-AGe model has similar structure as the ICRP model for the alkaline earth elements. The following parameters were mainly reevaluated: gastro-intestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0–80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general population exposed to ingested strontium radioisotopes.

  13. Process for the extraction of strontium from acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, E.P.; Dietz, M.L.

    1993-01-01

    The invention is a process for selectively extracting strontium values from aqueous nitric acid waste solutions containing these and other fission product values. The extractant solution is a macrocyclic polyether in an aliphatic hydrocarbon diluent containing a phase modifier. The process will selectively extract strontium values from nitric acid solutions which are up to 6 molar in nitric acid.

  14. Strontium Promotes Cementoblasts Differentiation through Inhibiting Sclerostin Expression In Vitro

    Directory of Open Access Journals (Sweden)

    Xingfu Bao

    2014-01-01

    Full Text Available Cementogenesis, performed by cementoblasts, is important for the repair of root resorption caused by orthodontic treatment. Based on recent studies, strontium has been applied for osteoporosis treatment due to its positive effect on osteoblasts. Although promising, the effect of strontium on cementoblasts is still unclear. So the aim of this research was to clarify and investigate the effect of strontium on cementogenesis via employing cementoblasts as model. A series of experiments including MTT, alkaline phosphatase activity, gene analysis, alizarin red staining, and western blot were carried out to evaluate the proliferation and differentiation of cementoblasts. In addition, expression of sclerostin was checked to analyze the possible mechanism. Our results show that strontium inhibits the proliferation of cementoblasts with a dose dependent manner; however, it can promote the differentiation of cementoblasts via downregulating sclerostin expression. Taking together, strontium may facilitate cementogenesis and benefit the treatment of root resorption at a low dose.

  15. Dance in Ancient Greek Culture

    OpenAIRE

    Spalva, Rita

    2015-01-01

    The greatness and harmony of ancient Greece has had an impact upon the development of the Western European culture to this day. The ancient Greek culture has influenced contemporary literature genres and systems of philosophy, principles of architecture, sculpture and drama and has formed basis for such sciences as astronomy and mathematics. The art of ancient Greece with its penchant for beauty and clarity has been the example of the humanity’s search for an aesthetic ideal. Despite only bei...

  16. Mathematics in ancient Greece

    CERN Document Server

    Dantzig, Tobias

    2006-01-01

    More than a history of mathematics, this lively book traces mathematical ideas and processes to their sources, stressing the methods used by the masters of the ancient world. Author Tobias Dantzig portrays the human story behind mathematics, showing how flashes of insight in the minds of certain gifted individuals helped mathematics take enormous forward strides. Dantzig demonstrates how the Greeks organized their precursors' melange of geometric maxims into an elegantly abstract deductive system. He also explains the ways in which some of the famous mathematical brainteasers of antiquity led

  17. Ancient concrete works

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    It is commonly believed that the ancient Romans were the first to create and use concrete. This is not true, as we can easily learn from the Latin literature itself. For sure, Romans were able to prepare high-quality hydraulic cements, comparable with the modern Portland cements. In this paper, we will see that the use of concrete is quite older, ranging back to the Homeric times. For instance, it was used for the floors of some courts and galleries of the Mycenaean palace at Tiryns

  18. Climate and Ancient Societies

    DEFF Research Database (Denmark)

    Climate, and human responses to it, have a strongly interconnected relationship. This when climate change occurs, the result of either natural or human causes, societies should react and adapt to these. But do they? If so, what is the nature of that change, and are the responses positive...... or negative for the long-term survival of social groups? In this volume, scholars from diverse disciplines including archaeology, geology and climate sciences explore scientific and material evidence for climate changes in the past, their causes, their effects on ancient societies and how those societies...

  19. Efficient cooling and trapping of strontium atoms.

    Science.gov (United States)

    Courtillot, I; Quessada, A; Kovacich, R P; Zondy, J J; Landragin, A; Clairon, A; Lemonde, P

    2003-03-15

    We report the capture of cold strontium atoms in a magneto-optical trap (MOT) at a rate of 4 x 10(10) atoms/s. The MOT is loaded from an atomic beam decelerated by a Zeeman slower operating with a focused laser beam. The 461-nm laser, used for both cooling and trapping, was generated by sum-frequency mixing in a KTP crystal with diode lasers at 813 nm and a Nd:YAG laser at 1064 nm. As much as 115 mW of blue light was obtained.

  20. Nondestructive measurement of environmental radioactive strontium

    Science.gov (United States)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Totsuka, Yumi; Murata, Jiro

    2014-03-01

    The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days), Cs-134 (2.1 years), Cs-137 (30 years), Sr-89 (51 days), and Sr-90 (29 years). We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

  1. Nondestructive measurement of environmental radioactive strontium

    Directory of Open Access Journals (Sweden)

    Saiba Shuntaro

    2014-03-01

    Full Text Available The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days, Cs-134 (2.1 years, Cs-137 (30 years, Sr-89 (51 days, and Sr-90 (29 years. We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

  2. Dielectric behaviour of strontium tartrate single crystals

    Indian Academy of Sciences (India)

    S K Arora; Vipul Patel; Brijesh Amin; Anjana Kothari

    2004-04-01

    Strontium tartrate trihydrate (STT) crystals have been grown in silica hydrogel. Various polarization mechanisms such as atomic polarization of lattice, orientational polarization of dipoles and space charge polarization in the grown crystals have been understood using results of the measurements of dielectric constant (') and dielectric loss (tan ) as functions of frequency and temperature. Ion core type polarization is seen in the temperature range 75–180°C, and above 180°C, there is interfacial polarization for relatively lower frequency range. One observes dielectric dispersion at lower frequency presumably due to domain wall relaxation.

  3. Crystalline silicotitanates for cesium/strontium removal

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.; Miller, J.; Sherman, J.

    1996-10-01

    A new class of inorganic ion exchangers called crystalline silicotitanates (CST) has been developed that exhibits very high selectivity for cesium and strontium in the highly alkaline radioactive wastes at the Hanford Site and other DOE sites. Tests have also shown that CSTs have high selectivity for cesium in acidic and neutral solutions. The ESP is supporting an effort at Sandia National Laboratories and Texas A & M University to further develop and characterize the important chemical and physical properties that will determine the applicability of CST to radioactive waste treatment at Hanford and other DOE facilities.

  4. Increased strontium uptake in trabecular bone of ovariectomized calcium-deficient rats treated with strontium ranelate or strontium chloride.

    Science.gov (United States)

    Pemmer, Bernhard; Hofstaetter, Jochen G; Meirer, Florian; Smolek, Stephan; Wobrauschek, Peter; Simon, Rolf; Fuchs, Robyn K; Allen, Matthew R; Condon, Keith W; Reinwald, Susan; Phipps, Roger J; Burr, David B; Paschalis, Eleftherios P; Klaushofer, Klaus; Streli, Christina; Roschger, Paul

    2011-11-01

    Based on clinical trials showing the efficacy to reduce vertebral and non-vertebral fractures, strontium ranelate (SrR) has been approved in several countries for the treatment of postmenopausal osteoporosis. Hence, it is of special clinical interest to elucidate how the Sr uptake is influenced by dietary Ca deficiency as well as by the formula of Sr administration, SrR versus strontium chloride (SrCl(2)). Three-month-old ovariectomized rats were treated for 90 days with doses of 25 mg kg(-1) d(-1) and 150 mg kg(-1) d(-1) of SrR or SrCl(2) at low (0.1% Ca) or normal (1.19% Ca) Ca diet. Vertebral bone tissue was analysed by confocal synchrotron-radiation-induced micro X-ray fluorescence and by backscattered electron imaging. Principal component analysis and k-means clustering of the acquired elemental maps of Ca and Sr revealed that the newly formed bone exhibited the highest Sr fractions and that low Ca diet increased the Sr uptake by a factor of three to four. Furthermore, Sr uptake in bone of the SrCl(2)-treated animals was generally lower compared with SrR. The study clearly shows that inadequate nutritional calcium intake significantly increases uptake of Sr in serum as well as in trabecular bone matrix. This indicates that nutritional calcium intake as well as serum Ca levels are important regulators of any Sr treatment.

  5. Whole-genome shotgun sequencing of mitochondria from ancient hair shafts

    DEFF Research Database (Denmark)

    Gilbert, M Thomas P; Tomsho, Lynn P; Rendulic, Snjezana

    2007-01-01

    Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously...

  6. Investigation of strontium accumulation on ovariectomized Sprague-Dawley rat tibia by micro-PIXE

    Science.gov (United States)

    Li, X.; Li, Y.; Jin, W.; Zheng, Y.; Rong, C.; Lyu, H.; Shen, H.

    2014-08-01

    Strontium ranelate is a newly developed drug effective in osteoporosis treatment by depressing bone resorption and maintaining bone formation. Strontium accumulation and distribution are determined in bones of rat after strontium ranelate administration by using micro-PIXE. The investigated rats are divided into four groups: (A) control, (B) ovariectomized, (C) ovariectomized followed with strontium chloride, (D) ovariectomized followed with strontium ranelate. It was found that strontium ranelate would result in increasing trabecular volume and decreasing bone resorption to treat osteoporosis. There are similar contours of calcium and strontium in two-dimensional images, while the strontium is not evenly distributed in the bone. It supports the conclusion that strontium has an affinity for bone and it is capable of replacing calcium atoms as a part of the strontium mechanism in the osteoporosis treatment. The results related to biochemistry are also discussed.

  7. Investigation of strontium accumulation on ovariectomized Sprague–Dawley rat tibia by micro-PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Li, X.; Li, Y. [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Jin, W. [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Zheng, Y.; Rong, C.; Lyu, H. [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Shen, H., E-mail: haoshen@fudan.edu.cn [Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2014-08-01

    Strontium ranelate is a newly developed drug effective in osteoporosis treatment by depressing bone resorption and maintaining bone formation. Strontium accumulation and distribution are determined in bones of rat after strontium ranelate administration by using micro-PIXE. The investigated rats are divided into four groups: (A) control, (B) ovariectomized, (C) ovariectomized followed with strontium chloride, (D) ovariectomized followed with strontium ranelate. It was found that strontium ranelate would result in increasing trabecular volume and decreasing bone resorption to treat osteoporosis. There are similar contours of calcium and strontium in two-dimensional images, while the strontium is not evenly distributed in the bone. It supports the conclusion that strontium has an affinity for bone and it is capable of replacing calcium atoms as a part of the strontium mechanism in the osteoporosis treatment. The results related to biochemistry are also discussed.

  8. Exploring Ancient Skies A Survey of Ancient and Cultural Astronomy

    CERN Document Server

    Kelley, David H

    2011-01-01

    Exploring Ancient Skies brings together the methods of archaeology and the insights of modern astronomy to explore the science of astronomy as it was practiced in various cultures prior to the invention of the telescope. The book reviews an enormous and growing body of literature on the cultures of the ancient Mediterranean, the Far East, and the New World (particularly Mesoamerica), putting the ancient astronomical materials into their archaeological and cultural contexts. The authors begin with an overview of the field and proceed to essential aspects of naked-eye astronomy, followed by an examination of specific cultures. The book concludes by taking into account the purposes of ancient astronomy: astrology, navigation, calendar regulation, and (not least) the understanding of our place and role in the universe. Skies are recreated to display critical events as they would have appeared to ancient observers—events such as the supernova of 1054 A.D., the "lion horoscope," and the Star of Bethlehem. Explori...

  9. Molecular genetic analysis of Dongzhou-period ancient human of Helingeer in Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The mtDNA hypervariable region I (HVR-I) of 10 ancient individuals from Dongzhou-period ancient human populations in Helingeer county of Inner Mongolia were amplified and sequenced to investigate the genetic structure. The relationships between the ancient population and related extant populations, as well as its possible origin at the molecular level, were also studied. Moreover, phylogenetic analysis and multi-dimensional scaling analysis were also performed based on the mtDNA data of the ancient population in Helingeer and the related Eurasian population. The results showed that the ancient population in Helingeer were closer to the northern Asian populations than to the other compared populations in matrilineal lineage. Combining the research results of archaeology and anthropology as well as molecular biology, we inferred that they were nomads who migrated from Mongolia plateau and cis-Baikal region to Helingeer in Inner Mongolia, China.

  10. Laser Stabilization with Laser Cooled Strontium

    DEFF Research Database (Denmark)

    Christensen, Bjarke Takashi Røjle

    The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting the nonli......The frequency stability of current state-of-the-art stabilized clock lasers are limited by thermal fluctuations of the ultra-stable optical reference cavities used for their frequency stabilization. In this work, we study the possibilities for surpassing this thermal limit by exploiting...... the nonlinear effects from coupling of an optical cavity to laser cooled atoms having a narrow transition linewidth. Here, we have realized such a system where a thermal sample of laser cooled strontium-88 atoms are coupled to an optical cavity. The strontium-88 atoms were probed on the narrow 1S0-3P1 inter......-combination line at 689 nm in a strongly saturated regime. The dynamics of the atomic induced phase shift and absorption of the probe light were experimentally studied in details with the purpose of applications to laser stabilization. The atomic sample temperature was in the mK range which brought this system out...

  11. Elastic Scattering Properties of Ultracold Strontium Atoms

    Institute of Scientific and Technical Information of China (English)

    张计才; 朱遵略; 刘玉芳; 孙金锋

    2011-01-01

    We investigate the elastic scattering properties of strontium atoms at ultracold temperatures.The scattering parameters,such as s-wave scattering lengths,effective ranges and p-wave scattering lengths,are calculated for all stable isotope combinations of Sr atoms by the quantal method and semiclassical method,respectively.Good agreements are obtained.The scattering parameters are very sensitive to small changes of the reduced mass.Due to the repulsive interisotope and intraisotope s-wave scattering length and large elastic cross sections,84Sr-86Srmixture is a good candidate to realize Bose-Bose quantum degenerate atomic gases.%We investigate the elastic scattering properties of strontium atoms at ultracold temperatures. The scattering parameters, such as s-wave scattering lengths, effective ranges and p-wave scattering lengths, are calculated for all stable isotope combinations of Sr atoms by the quantal method and semiclassical method, respectively. Good agreements are obtained. The scattering parameters are very sensitive to small changes of the reduced mass. Due to the repulsive interisotope and intraisotope s-wave scattering length and large elastic cross sections, MSr-s(iSr mixture is a good candidate to realize Bose-Bose quantum degenerate atomic gases.

  12. Seaweed against strontium and preussian blue against cesium

    Directory of Open Access Journals (Sweden)

    G Michanek

    1988-06-01

    Full Text Available The fact that alginates bind strontium and cyanates bind cesium and are capable of removing these elements from living organisms is scientifically verified. Zeolites offer another possibility for exchange of these ions. Practical research should be initiated to find the right doses and procedure to decrease the body burden of radioactive isotopes in reindeer.Alger mot strontium och berlinerblått mot cesium.Abstract in Swedish / Sammanfattning: Mitt budskap år kort: Alger binder strontium, Berlinerblått binder cesium, Sätt fart på forskning och forsök!

  13. X-Ray Absorption Spectroscopy of Strontium(II) Coordination.

    Science.gov (United States)

    O'Day; Newville; Neuhoff; Sahai; Carroll

    2000-02-15

    Detailed analyses of crystalline, hydrated, and precipitated strontium compounds and an aqueous strontium solution by synchrotron extended X-ray absorption fine structure (EXAFS) were used to quantify local thermal and static disorder and to characterize strontium coordination in a variety of oxygen-ligated bonding environments. Analysis of anharmonic vibrational disorder (i.e., significant contribution from a third cumulant term (C(3)) in the EXAFS phase-shift function) in compounds with low and high static disorder around strontium showed that first-shell anharmonic contributions were generally not significant above experimental error in the EXAFS fits (R+/-0.02 Å with and without C(3)). The only case in which a significant apparent decrease in Sr-O distance was observed with increasing temperature, and for which a third cumulant term was significant, was for dilute strontium in aqueous solution. Empirical parameterization of Debye-Waller factor (sigma(2)) for strontium compounds as a function of backscatterer atomic number (Z), interatomic Sr-Z distance, and temperature of spectral data collection showed systematic increases in sigma(2) as a function of increasing temperature and Sr-Z bond length. At values of sigma(2) greater than approximately 0.025 Å(2) (for N3 Å), backscattering was generally not significant above noise levels in spectra of compounds of known crystal structure. Comparison of the EXAFS spectra of freshly precipitated SrCO(3) (spectra collected wet) to that of dry, powdered strontianite (SrCO(3)(s)) indicated no significant differences in the local atomic structure around strontium. Analysis of partially hydrated strontium in natural Ca-zeolite (heulandite) showed that strontium is substituted only in the calcium (Ca2) site. Backscattering from aluminum and silicon atoms in the zeolite framework were apparent in the EXAFS spectra at low and room temperature at distances from central strontium of strontium structural coordination determined

  14. TEM observation of sintered permanent magnetic strontium ferrite

    Institute of Scientific and Technical Information of China (English)

    YU Hongya; LIU Zhengyi; ZENG Dechang

    2006-01-01

    Sintered permanent magnetic strontium ferrites were studied using transmission electron microscopy to investigate the microstructure morphology and its correlation with the magnetic properties. The present study shows that the microstructure of sintered permanent magnetic strontium ferrites is an important parameter in determining their magnetic properties. The microstructure morphology in low-performance ferrite magnet is obviously different from high-performance one. Themagnetic properties of sintered permanent strontium ferrite depend strongly on the orientation degree of strong magnetic crystals. The presence of ferric oxidephase in ferrite magnet can deteriorate the magnetic properties. Moreover, proper quantities of crystal defects are beneficial to high coercive force due to the fixing of magnetic domain.

  15. Characterization of Ancient Tripitaka

    Science.gov (United States)

    Gong, Y. X.; Geng, L.; Gong, D. C.

    2015-08-01

    Tripitaka is the world's most comprehensive version of Buddhist sutra. There are limited numbers of Tripitaka currently preserved, most of them present various patterns of degradation. As little is known about the materials and crafts used in Tripitaka, it appeared necessary to identify them, and to further define adapted conservation treatment. In this work, a study concerning the paper source and dyestuff of the Tripitaka from approximate 16th century was carried out using fiber analysis and thin-layer chromatography (TLC). The results proved that the papers were mainly made from hemp or bark of mulberry tree, and indigo was used for colorizing the paper. At the end, we provide with suggestions for protecting and restoring the ancient Tripitaka.

  16. Effect of long-term treatment with strontium ranelate on bone strontium content

    DEFF Research Database (Denmark)

    Bärenholdt, Olaf; Kolthoff, Niels; Nielsen, Stig Pors

    2009-01-01

    in a 3 years open study of the effect on bone Sr. The group was treated with 2 g SrR/day, 17 of the group had received active treatment for 4-5 years before the study. DXA BMD measurements and DPA measurements of the relative bone strontium hydroxy apatite termed %Sr (SrHA/(CaHA+SrHA)) were done...... at the end of treatment. No effect was demonstrated on distal radius relative bone Ca hydroxy apatite. Bone strontium uptake and retention data were compatible with a power function model. Withdrawal of SrR resulted in a decline in bone Sr, but 73 %Sr and 67 %Sr, respectively remained in UD-radius three...

  17. Genome-wide patterns of selection in 230 ancient Eurasians

    Science.gov (United States)

    Mathieson, Iain; Lazaridis, Iosif; Rohland, Nadin; Mallick, Swapan; Patterson, Nick; Roodenberg, Songül Alpaslan; Harney, Eadaoin; Stewardson, Kristin; Fernandes, Daniel; Novak, Mario; Sirak, Kendra; Gamba, Cristina; Jones, Eppie R.; Llamas, Bastien; Dryomov, Stanislav; Pickrel, Joseph; Arsuaga, Juan Luís; de Castro, José María Bermúdez; Carbonell, Eudald; Gerritsen, Fokke; Khokhlov, Aleksandr; Kuznetsov, Pavel; Lozano, Marina; Meller, Harald; Mochalov, Oleg; Moiseyev, Vayacheslav; Rojo Guerra, Manuel A.; Roodenberg, Jacob; Vergès, Josep Maria; Krause, Johannes; Cooper, Alan; Alt, Kurt W.; Brown, Dorcas; Anthony, David; Lalueza-Fox, Carles; Haak, Wolfgang; Pinhasi, Ron; Reich, David

    2016-01-01

    Ancient DNA makes it possible to directly witness natural selection by analyzing samples from populations before, during and after adaptation events. Here we report the first scan for selection using ancient DNA, capitalizing on the largest genome-wide dataset yet assembled: 230 West Eurasians dating to between 6500 and 1000 BCE, including 163 with newly reported data. The new samples include the first genome-wide data from the Anatolian Neolithic culture whose genetic material we extracted from the DNA-rich petrous bone and who we show were members of the population that was the source of Europe’s first farmers. We also report a complete transect of the steppe region in Samara between 5500 and 1200 BCE that allows us to recognize admixture from at least two external sources into steppe populations during this period. We detect selection at loci associated with diet, pigmentation and immunity, and two independent episodes of selection on height. PMID:26595274

  18. Production of high-n strontium Rydberg atoms

    Science.gov (United States)

    Ye, S.; Zhang, X.; Killian, T. C.; Dunning, F. B.; Hiller, M.; Yoshida, S.; Burgdörfer, J.

    2014-04-01

    The photoexcitation of strontium Rydberg atoms with n ~ 300 is being examined using a crossed laser-atom beam approach to enable study of quasi-stable two-electron excited states and of strongly-coupled Rydberg systems.

  19. Progress Toward Intercombination Line Cooling in Strontium

    Science.gov (United States)

    Nagel, Sarah B.; Simien, Clayton; Vudayagiri, Ashok; Killian, Thomas C.

    2002-05-01

    An external-cavity, grating-tuned diode laser system is being developed for laser cooling on the 689 nm intercombination line of Strontium (^1S0 arrow ^2P_1, Γ= (2π)*7.5 kHz), using commercially availably laser diodes. We are making progress toward locking the external-cavity diode laser to a heat pipe to produce a few mW of tunable, stabilized, single-mode power at 689 nm. The output from this laser can be injected into a slave laser to produce up to 35 mW of stabilized polarized single-mode power. The completed laser system will be used for both high-resolution spectroscopy and laser cooling. The design of this laser system as well as preliminary results will be presented.

  20. Pathogens and host immunity in the ancient human oral cavity

    DEFF Research Database (Denmark)

    Warinner, Christina; Rodrigues, João F Matias; Vyas, Rounak

    2014-01-01

    cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction......Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral...... of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, 'red complex' pathogens and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental...

  1. Porous allograft bone scaffolds: doping with strontium.

    Directory of Open Access Journals (Sweden)

    Yantao Zhao

    Full Text Available Strontium (Sr can promote the process of bone formation. To improve bioactivity, porous allograft bone scaffolds (ABS were doped with Sr and the mechanical strength and bioactivity of the scaffolds were evaluated. Sr-doped ABS were prepared using the ion exchange method. The density and distribution of Sr in bone scaffolds were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES, X-ray photoelectron spectroscopy (XPS, and energy-dispersive X-ray spectroscopy (EDS. Controlled release of strontium ions was measured and mechanical strength was evaluated by a compressive strength test. The bioactivity of Sr-doped ABS was investigated by a simulated body fluid (SBF assay, cytotoxicity testing, and an in vivo implantation experiment. The Sr molar concentration [Sr/(Sr+Ca] in ABS surpassed 5% and Sr was distributed nearly evenly. XPS analyses suggest that Sr combined with oxygen and carbonate radicals. Released Sr ions were detected in the immersion solution at higher concentration than calcium ions until day 30. The compressive strength of the Sr-doped ABS did not change significantly. The bioactivity of Sr-doped material, as measured by the in vitro SBF immersion method, was superior to that of the Sr-free freeze-dried bone and the Sr-doped material did not show cytotoxicity compared with Sr-free culture medium. The rate of bone mineral deposition for Sr-doped ABS was faster than that of the control at 4 weeks (3.28 ± 0.23 µm/day vs. 2.60 ± 0.20 µm/day; p<0.05. Sr can be evenly doped into porous ABS at relevant concentrations to create highly active bone substitutes.

  2. High temperature annealing studies of strontium ion implanted glassy carbon

    Science.gov (United States)

    Odutemowo, O. S.; Malherbe, J. B.; Prinsloo, L.; Langa, D. F.; Wendler, E.

    2016-03-01

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 1016 ions/cm2 at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

  3. High temperature annealing studies of strontium ion implanted glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Odutemowo, O.S., E-mail: u12052613@tuks.co.za [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Malherbe, J.B.; Prinsloo, L.; Langa, D.F. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Wendler, E. [Institut für Festkörperphysik, Friedrich-Schiller University, Jena (Germany)

    2016-03-15

    Glassy carbon samples were implanted with 200 keV strontium ions to a fluence of 2 × 10{sup 16} ions/cm{sup 2} at room temperature. Analysis with Raman spectroscopy showed that ion bombardment amorphises the glassy carbon structure. Partial recovery of the glassy carbon structure was achieved after the implanted sample was vacuum annealed at 900 °C for 1 h. Annealing the strontium ion bombarded sample at 2000 °C for 5 h resulted in recovery of the glassy carbon substrate with the intensity of the D peak becoming lower than that of the pristine glassy carbon. Rutherford backscattering spectroscopy (RBS) showed that the implanted strontium diffused towards the surface of the glassy carbon after annealing the sample at 900 °C. This diffusion was also accompanied by loss of the implanted strontium. Comparison between the as-implanted and 900 °C depth profiles showed that less than 30% of the strontium was retained in the glassy carbon after heat treatment at 900 °C. The RBS profile after annealing at 2000 °C indicated that no strontium ions were retained after heat treatment at this temperature.

  4. Layout of Ancient Maya Cities

    Science.gov (United States)

    Aylesworth, Grant R.

    Although there is little doubt that the ancient Maya of Mesoamerica laid their cities out based, in part, on astronomical considerations, the proliferation of "cosmograms" in contemporary scholarly discourse has complicated matters for the acceptance of rigorous archaeoastronomical research.

  5. Astronomical Significance of Ancient Monuments

    Science.gov (United States)

    Simonia, I.

    2011-06-01

    Astronomical significance of Gokhnari megalithic monument (eastern Georgia) is considered. Possible connection of Amirani ancient legend with Gokhnari monument is discussed. Concepts of starry practicality and solar stations are proposed.

  6. Hunting for Ancient Rocky Shores.

    Science.gov (United States)

    Johnson, Markes E.

    1988-01-01

    Promotes the study of ancient rocky shores by showing how they can be recognized and what directions future research may follow. A bibliography of previous research articles, arranged by geologic period, is provided in the appendix to this paper. (CW)

  7. Shifting sediment sources in the world's longest river: A strontium isotope record for the Holocene Nile

    Science.gov (United States)

    Woodward, Jamie; Macklin, Mark; Fielding, Laura; Millar, Ian; Spencer, Neal; Welsby, Derek; Williams, Martin

    2015-12-01

    We have reconstructed long-term shifts in catchment sediment sources by analysing, for the first time, the strontium (Sr) and neodymium (Nd) isotope composition of dated floodplain deposits in the Desert Nile. The sediment load of the Nile has been dominated by material from the Ethiopian Highlands for much of the Holocene, but tributary wadis and aeolian sediments in Sudan and Egypt have also made major contributions to valley floor sedimentation. The importance of these sources has shifted dramatically in response to global climate changes. During the African Humid Period, before c. 4.5 ka, when stronger boreal summer insolation produced much higher rainfall across North Africa, the Nile floodplain in northern Sudan shows a tributary wadi input of 40-50%. Thousands of tributary wadis were active at this time along the full length of the Saharan Nile in Egypt and Sudan. As the climate became drier after 4.5 ka, the valley floor shows an abrupt fall in wadi inputs and a stronger Blue Nile/Atbara contribution. In the arid New Kingdom and later periods, in palaeochannel fills on the margins of the valley floor, aeolian sediments replace wadi inputs as the most important secondary contributor to floodplain sedimentation. Our sediment source data do not show a measurable contribution from the White Nile to the floodplain deposits of northern Sudan over the last 8500 years. This can be explained by the distinctive hydrology and sediment delivery dynamics of the upper Nile basin. High strontium isotope ratios observed in delta and offshore records - that were previously ascribed to a stronger White Nile input during the African Humid Period - may have to be at least partly reassessed. Our floodplain Sr records also have major implications for bioarchaeologists who carry out Sr isotope-based investigations of ancient human remains in the Nile Valley because the isotopic signature of Nile floodplain deposits has shifted significantly over time.

  8. THE BEST ATHLETES IN ANCIENT ROME WERE VEGETARIAN!

    Directory of Open Access Journals (Sweden)

    Umile Giuseppe Longo

    2008-12-01

    Full Text Available The figure of gladiators recalls the ideas of strength, hard training, endurance, and deadly efficiency: a perfect fighting machine. Historically, a gladiator was a sort of sport hero, and gladiator's medicine probably one of the first forms of organised sports medicine. Statues and paintings of the ancient roman period tell us of this astonishing world of fighters. There are traces of famous gladiators all over the known world at Roman times, resembling our Mohammad Ali or Mike Tyson. Most of them grew up in fighting schools, the most famous in Capua, near Naples in Italy: Spartacus, the rebel gladiator who inflicted a severe defeat to Roman army, came from there. Gladiators had to endure long session of training to fight in the arena. Considering the modern diets of strength athletes, we should expect that gladiators had a high protein diet. However, analysis of their bones has put forward the hypothesis that gladiators were vegetarian athletes: in his accounts of Rome, the ancient historian Plinius refers to gladiators as "hordearii" (barley-eaters (Eichholz et al., 1938. Plants contain higher levels of strontium than animal tissues. People who consume more plants and less meat will build up measurably higher levels of strontium in their bones. Levels of strontium in the gladiators' bones were two times as high than the bones of contemporary Ephesians (Kanz and Grossschmidt, 2007. Roman army troopers, the "legionnaires", had daily expenditure of energy that can be estimated at around 5000 kcal for the legionnaire performing engineer work and at 6000 kcal for the legionnaire in war action. At present, only workmen and sportsmen reach such levels of energy expenditure (Fornaris and Aubert, 1998. Legionnaires were able to endure long war campaignes and endless "magnis itineribus" (forced marches with incredible resistance to fatigue. The legionnaire's daily ration consisted of 78% carbohydrates, mainly from wheat or barley. This diet has the

  9. Perspectives for DNA studies on polar ice cores

    DEFF Research Database (Denmark)

    Hansen, Anders J.; Willerslev, E.

    2002-01-01

    Recently amplifiable ancient DNA was obtained from a Greenland ice core. The DNA revealed a diversity of fungi, plants, algae and protists and has thereby expanded the range of detectable organic material in fossil glacier ice. The results suggest that ancient DNA can be obtained from other ice...... cores as well. Here, we present some future perspectives for DNA studies on polar ice cores in regard to molecular ecology, DNA damage and degradation, anabiosis and antibiotic resistance genes. Finally, we address some of the methodological problems connected to ancient DNA research....

  10. Strontium-90 at the Hanford Site and its ecological implications

    Energy Technology Data Exchange (ETDEWEB)

    RE Peterson; TM Poston

    2000-05-22

    Strontium-90, a radioactive contaminant from historical operations at the U.S. Department of Energy (DOE) Hanford Site, enters the Columbia River at several locations associated with former plutonium production reactors at the Site. Strontium-90 is of concern to humans and the environment because of its moderately long half-life (29.1 years), its potential for concentrating in bone tissue, and its relatively high energy of beta decay. Although strontium-90 in the environment is not a new issue for the Hanford Site, recent studies of near-river vegetation along the shoreline near the 100 Areas raised public concern about the possibility of strontium-90-contaminated groundwater reaching the riverbed and fall chinook salmon redds. To address these concerns, DOE asked Pacific Northwest National Laboratory (PNNL) to prepare this report on strontium-90, its distribution in groundwater, how and where it enters the river, and its potential ecological impacts, particularly with respect to fall chinook salmon. The purpose of the report is to characterize groundwater contaminants in the near-shore environment and to assess the potential for ecological impact using salmon embryos, one of the most sensitive ecological indicators for aquatic organisms. Section 2.0 of the report provides background information on strontium-90 at the Hanford Site related to historical operations. Public access to information on strontium-90 also is described. Section 3.0 focuses on key issues associated with strontium-90 contamination in groundwater that discharges in the Hanford Reach. The occurrence and distribution of fall chinook salmon redds in the Hanford Reach and characteristics of salmon spawning are described in Section 4.0. Section 5.0 describes the regulatory standards and criteria used to set action levels for strontium-90. Recommendations for initiating additional monitoring and remedial action associated with strontium-90 contamination at the Hanford Site are presented in Section 6

  11. Did the ancient Egyptians migrate to ancient Nigeria?

    Directory of Open Access Journals (Sweden)

    Jock M. Agai

    2014-01-01

    Full Text Available Literatures concerning the history of West African peoples published from 1900 to 1970 debate�the possible migrations of the Egyptians into West Africa. Writers like Samuel Johnson and�Lucas Olumide believe that the ancient Egyptians penetrated through ancient Nigeria but Leo�Frobenius and Geoffrey Parrinder frowned at this opinion. Using the works of these early�20th century writers of West African history together with a Yoruba legend which teaches�about the origin of their earliest ancestor(s, this researcher investigates the theories that the�ancient Egyptians had contact with the ancient Nigerians and particularly with the Yorubas.Intradisciplinary and/or interdisciplinary implications: There is an existing ideology�amongst the Yorubas and other writers of Yoruba history that the original ancestors of�the Yorubas originated in ancient Egypt hence there was migration between Egypt and�Yorubaland. This researcher contends that even if there was migration between Egypt and�Nigeria, such migration did not take place during the predynastic and dynastic period as�speculated by some scholars. The subject is open for further research.

  12. Studies of Bone Metabolism with the Aid of Radioactive Strontium

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.C.; Copp, D.H., M.D.

    1948-04-01

    The kinetics of skeletal uptake and urinary excretion of radiostrontium were studied during the critieal first hour following intraperitoneal injection of a carrier-free dose. These experiments not only provided valuable data con.cerning the metabolism and fixation of this important fission product, but, because of the close similarity of strontium and calcium, also gave basic information on the process of calcification. Three groups of rats were compared: normal mature adults, young growing normal animals, and young rachitic rats. In all groups, the blood radioactive strontium rose to a maximum in 10-15 minutes, and then declined as the strontium continued to deposit in the skeleton or to be excreted in the urine. Muscle and skin strontium curves followed those of blood quite closely, suggesting a rapid equilibrium between their extracellular fluid and blood plasma. In all groups there was a continous uptake of strontium by the skeleton. In the adults, this was almost constant, suggesting uptek e by absorption and exchange with the calcium of the bone mineral. In the young rats, both normal and rachitic, the very rapid initial rate of uptake of radio-strontium tapered off sharply with time, indicating that some of this radio-element was coming back from the bone into the blood stream. This suggested a rapid labile combination of strontiunl in these animals, which, since it also occured in the rachitic group in which normal calcification is inhibited, probably associated with the protein osteoid matrix present in both. A hypothetical calcification mechanism was suggested by these findings. Urinary excretion and renal clearance of strontium was constant in all three groups, but the clearance was almost ten times as great in the rachitic as in the normal young and adult rats. This would seem to indicate a direct effect of rickets on the renal mechanism of radiostrontium (and calcium) excretion.

  13. Eu(2+) luminescence in strontium aluminates.

    Science.gov (United States)

    Dutczak, D; Jüstel, T; Ronda, C; Meijerink, A

    2015-06-21

    The luminescence properties of Eu(2+) doped strontium aluminates are reported and reviewed for a variety of aluminates, viz. SrAl12O19, SrAl4O7, Sr4Al14O25, SrAl2O4 and Sr3Al2O6. The aim of the research is to investigate the role of local coordination and covalency of the aluminate host lattice, related to the Sr/Al ratio, on the optical properties of the Eu(2+) ion. The UV and VUV excited luminescence spectra as well as luminescence decay curves were recorded to characterize the luminescence properties of the investigated aluminates. The emission of Eu(2+) ions varies over a wide spectral range, from ultraviolet (UV) to red, for the series of aluminates. The variation in emission color can be related to the crystal-field splitting of the 5d levels and the covalent interaction with the surrounding oxygen anions. In the least covalent material, viz. SrAl12O19:Eu(2+), narrow line emission due to the (6)P7/2-(8)S7/2 transition occurs at 4 K, indicating that the 4f(6)5d excited state is situated above the (6)P7/2(4f(7)) excited state around 360 nm. The most alkaline material, viz. Sr3Al2O6:Eu(2+) is the most covalent host and exhibits several d-f emission bands in the yellow to red spectral range due to the Eu(2+) ions located on different crystallographic Sr(2+) sites. The Eu(2+) emission spectra in the other aluminates confirm the trend that with increasing Sr/Al ratio the Eu(2+) emission shifts to longer wavelengths. Interesting differences are observed for the Eu(2+) from different crystallographic sites which cannot always be related with apparent differences in the first oxygen coordination sphere. The discussion gives insight into how in a similar class of materials, strontium aluminates, the emission color of Eu(2+) can be tuned over a wide spectral region.

  14. Radiopaque strontium fluoroapatite glass-ceramics

    Directory of Open Access Journals (Sweden)

    Wolfram eHöland

    2015-10-01

    Full Text Available The controlled precipitation of strontium fluoroapatite crystals, was studied in four base glass compositions derived from the SiO2 – Al2O3 – Y2O3 – SrO – Na2O – K2O/Rb2O/Cs2O – P2O5 – F system. The crystal phase formation of these glasses and the main properties of the glass-ceramics, such as thermal and optical properties and radiopacity were compared with a fifth, a reference glass-ceramic. The reference glass-ceramic was characterized as Ca-fluoroapatite glass-ceramic. The four strontium fluoroapatite glass-ceramics showed the following crystal phases: a Sr5(PO43F – leucite, KAlSi2O6 , b Sr5(PO43F – leucite, KAlSi2O6, and nano-sized NaSrPO4 c Sr5(PO43F – pollucite, CsAlSiO4 , and nano-sized NaSrPO4, d Sr5(PO43F – Rb-leucite, RbAlSi2O6, and nano-sized NaSrPO4.The proof of crystal phase formation was possible by X-ray diffraction (XRD. The microstructures, which were studied using scanning electron microscopy (SEM demonstrated a uniform distribution of the crystals in the glass matrix. The Sr-fluoroapatites were precipitated based on an internal crystallization process, and the crystals demonstrated a needlelike morphology. The study of the crystal growth of needlelike Sr-fluoroapatites gave a clear evidence of an Ostwald ripening mechanism.The formation of leucite, pollucite and Rb-leucite was based on a surface crystallization mechanism. Therefore, a twofold crystallization mechanism was successfully applied to develop these types of glass-ceramics. The main focus of this study was the controlled development of glass-ceramics exhibiting high radiopacity in comparison to the reference glass-ceramic. This goal could be achieved with all four glass-ceramics with the preferred development of the Sr-fluoroapatite – pollucite-type glass-ceramic. In addition to this main development, it was possible to control the thermal properties. Especially the Rb-leucite containing glass-ceramic showed the highest coefficient of thermal

  15. Stable strontium isotopic ratios from archaeological organic remains from the Thorsberg peat bog

    DEFF Research Database (Denmark)

    Nosch, Marie-Louise Bech; von Carnap-Bornheim, Claus; Grupe, Gisela;

    2007-01-01

    Pilot study analysing stable strontium isotopic ratios from Iron Age textile and leather finds from the Thorsberg peat bog.......Pilot study analysing stable strontium isotopic ratios from Iron Age textile and leather finds from the Thorsberg peat bog....

  16. Effects of strontium and boron interactions in Al-7Si alloys

    Directory of Open Access Journals (Sweden)

    Chen Xiang

    2010-11-01

    Full Text Available Effects of boron and strontium combined treatment on the microstructure of hypoeutectic Al-7Si alloy have been studied. Experimental results show that strontium has no significant effect on the grain refinement efficiency of boron and the eutectic silicon modification efficiency is not only related to the strontium content but also related to the boron content in the Al-7Si alloy melt. There is a negative interaction between boron and strontium that results in the formation of a strontium-boron-aluminum containing compound, which reduces the effective strontium level and decreases the eutectic silicon modification efficiency substantially. The refinement and modification mechanisms remain unchanged after the combined addition of strontium and boron. Based on the experimental results, a model for assessing the modification level in the Al-Si alloy melts after combined addition of boron and strontium was presented.

  17. [Cytotoxicity of the strontium-substituted hydroxyapatite evaluated by MTT colorimetry].

    Science.gov (United States)

    Fu, Y; Chen, D; Zhang, J

    2001-09-01

    This study was conducted to evaluate the cytotoxicity of strontium-substituted hydroxyapatite by methyl thiazolyl tetrazolium (MTT) colorimetry. We used the MTT method to assay the cytotoxicity of the strontium-substituted hydroxyapatite containing different strontium concentrations (1%, 5%, 10%, 100% Sr2+) and the pure hydroxyapatite. The results showed that the cytotoxicity scores of the different materials were grade 0 or grade 1. These led us to the conclusion that strontium-substituted hydroxyapatite has good biocompatibility.

  18. The Ancient Evolutionary History of Polyomaviruses.

    Directory of Open Access Journals (Sweden)

    Christopher B Buck

    2016-04-01

    Full Text Available Polyomaviruses are a family of DNA tumor viruses that are known to infect mammals and birds. To investigate the deeper evolutionary history of the family, we used a combination of viral metagenomics, bioinformatics, and structural modeling approaches to identify and characterize polyomavirus sequences associated with fish and arthropods. Analyses drawing upon the divergent new sequences indicate that polyomaviruses have been gradually co-evolving with their animal hosts for at least half a billion years. Phylogenetic analyses of individual polyomavirus genes suggest that some modern polyomavirus species arose after ancient recombination events involving distantly related polyomavirus lineages. The improved evolutionary model provides a useful platform for developing a more accurate taxonomic classification system for the viral family Polyomaviridae.

  19. Surface functionalization with strontium-containing nanocomposite coatings via EPD.

    Science.gov (United States)

    Ma, Kena; Huang, Dan; Cai, Jing; Cai, Xinjie; Gong, Lingling; Huang, Pin; Wang, Yining; Jiang, Tao

    2016-10-01

    Metal orthopedic implants still face challenges in some compromised conditions, partly due to bio-inertness. The present study aimed to functionalize metallic implants with organic-inorganic nanocomposite (strontium-containing chitosan/gelatin) coatings through a simple single-step electrophoretic deposition under mild conditions. The surface characterization and in vitro cellular response were studied and compared with chitosan/gelatin (CS/G) coatings. SEM images suggested the inorganic nanoparticles may be encapsulated within or mixed with organic polymers. The XRD patterns showed that strontium carbonate was generated in the coatings. The TEM images revealed strontium-containing nanoparticles were released from the coatings in PBS. The continuous release after the initial burst release ensured the enduring effects of the functionalized surface. The tensile bond strength of the coatings to the substrates increased after the addition of strontium. In vitro cellular study confirmed that strontium-containing coatings supported the proliferation of MC3T3-E1 cells and exhibited excellent ability to enhance the differentiation of such pre-osteoblasts. Therefore, such organic-inorganic nanocomposite coatings are a promising candidate to functionalize orthopedic implant surfaces.

  20. [Mechanisms of neurotransmitter release facilitation in strontium solutions].

    Science.gov (United States)

    Mukhamed'iarov, M A; Kochunova, Iu O; Telina, E N; Zefirov, A L

    2008-02-01

    Mechanisms of neurotransmitter release facilitation were studied using electrophysiological recording of end-plate currents (EPC) and nerve ending (NE) responses after substitution of extracellular Ca ions with Sr ions at the frog neuromuscular junction. The solutions with 0.5 mM concentration of Ca ions (calcium solution) or 1 mM concentration of Sr ions (strontium solution) were used where baseline neurotransmitter release (at low-frequency stimulation) is equal. Decay of paired-pulse facilitation of EPC at calcium solutions with increase of interpulse interval from 5 to 500 ms was well described by three-exponential function consisting of early, first and second components. Facilitation at strontium solutions was significantly diminished due mainly to decrease of early and first components. At the same time, EPC facilitation with rhythmic stimulation (10 or 50 imp/s) at strontium solutions was significantly increased. Also more pronounced decrease of NE response 3rd phase, reflecting potassium currents was detected under rhythmic stimulation of 50 imp/s at strontium solutions comparing to calcium solutions. It was concluded that facilitation sites underlying first and early components had lower affinity to Sr ions than to Ca ions. The enhancement of frequency facilitation at strontium solutions is mediated by two mechanisms: more pronounced broadening of NE action potential and increase of bivalent cation influx due to feebly marked activation of Ca(2+)-dependent potassium current by Sr ions, and slower dynamics of Sr(2+) removal from NE axoplasm comparing to Ca(2+).

  1. The importance of studying inherited hematological disorders in ancient Anatolian populations

    Directory of Open Access Journals (Sweden)

    Yeşim Doğan Alakoç

    2011-12-01

    Full Text Available Before analysis of DNA from ancient remains was possible, anthropologists studied evolution and migration patterns using data obtained from population genetic studies on modern populations combined with data obtained from morphological evaluations of ancient remains. Currently, DNA analysis of ancient populations is making a valuable contribution to these efforts. Researchers that perform ancient DNA analysis prefer to study polymorphisms on the Y chromosome or mitochondrial DNA because the results are easier to statistically evaluate. To evaluate polymorphisms on diploid genomes, which are more informative, only mutations that have been extensively examined in modern populations should be chosen. The most extensively evaluated mutations are those related to prevalent inherited disorders. As such, beta-thalassemia, sickle cell anemia, FVL mutation of globin and the factor V genes are good candidates for DNA studies in ancient populations. These mutations are common in Anatolia, host to many civilizations since the Paleolithic period. This history makes Anatolia a good place for conducting research that could enhance our understanding of human evolution and migration patterns.

  2. Fast, Accurate and Automatic Ancient Nucleosome and Methylation Maps with epiPALEOMIX.

    Science.gov (United States)

    Hanghøj, Kristian; Seguin-Orlando, Andaine; Schubert, Mikkel; Madsen, Tobias; Pedersen, Jakob Skou; Willerslev, Eske; Orlando, Ludovic

    2016-12-01

    The first epigenomes from archaic hominins (AH) and ancient anatomically modern humans (AMH) have recently been characterized, based, however, on a limited number of samples. The extent to which ancient genome-wide epigenetic landscapes can be reconstructed thus remains contentious. Here, we present epiPALEOMIX, an open-source and user-friendly pipeline that exploits post-mortem DNA degradation patterns to reconstruct ancient methylomes and nucleosome maps from shotgun and/or capture-enrichment data. Applying epiPALEOMIX to the sequence data underlying 35 ancient genomes including AMH, AH, equids and aurochs, we investigate the temporal, geographical and preservation range of ancient epigenetic signatures. We first assess the quality of inferred ancient epigenetic signatures within well-characterized genomic regions. We find that tissue-specific methylation signatures can be obtained across a wider range of DNA preparation types than previously thought, including when no particular experimental procedures have been used to remove deaminated cytosines prior to sequencing. We identify a large subset of samples for which DNA associated with nucleosomes is protected from post-mortem degradation, and nucleosome positioning patterns can be reconstructed. Finally, we describe parameters and conditions such as DNA damage levels and sequencing depth that limit the preservation of epigenetic signatures in ancient samples. When such conditions are met, we propose that epigenetic profiles of CTCF binding regions can be used to help data authentication. Our work, including epiPALEOMIX, opens for further investigations of ancient epigenomes through time especially aimed at tracking possible epigenetic changes during major evolutionary, environmental, socioeconomic, and cultural shifts.

  3. Ancient bacteria of the Ötzi’s microbiome: a genomic tale from the Copper Age

    OpenAIRE

    Lugli, Gabriele Andrea; Milani, Christian; Mancabelli, Leonardo; Turroni, Francesca; Ferrario, Chiara; Duranti, Sabrina; Van Sinderen, Douwe; Ventura, Marco

    2017-01-01

    Background Ancient microbiota information represents an important resource to evaluate bacterial evolution and to explore the biological spread of infectious diseases in history. The soft tissue of frozen mummified humans, such as the Tyrolean Iceman, has been shown to contain bacterial DNA that is suitable for population profiling of the prehistoric bacteria that colonized such ancient human hosts. Results Here, we performed a microbial cataloging of the distal gut microbiota of the Tyrolean...

  4. Strontium-Containing Apatite/Poly Lactide Composites Favoring Osteogenic Differentiation and in Vivo Bone Formation

    NARCIS (Netherlands)

    Luo, Xiaoman; Barbieri, D.; Zhang, Yunfei; Yan, Yonggang; Bruijn, de Joost D.; Yuan, Huipin

    2015-01-01

    Strontium was shown to enhance bone growth; however, its oral administration may lead to severe side effects. The application of strontium in orthopedic biomaterials may therefore be an alternative to achieve targeted and sustained strontium treatment to the surgery site in aid of bone growth locall

  5. Neonatal medicine in ancient art.

    Science.gov (United States)

    Yurdakök, Murat

    2010-01-01

    There are a limited number of artistic objects from ancient times with particular importance in neonatal medicine. The best examples are figurines from ancient Egypt of Isis nursing Horus, showing the importance of breastfeeding. The earliest images of the human fetus were made by the Olmecs in Mexico around 1200- 400 BCE. One of the earliest representations of congenital anomalies is a figurine of diencephalic twins thought to be the goddess of Anatolia, dated to around 6500 BCE. In addition to these figurines, three sets of twins in the ancient world have medical importance, and Renaissance artists often used them as a subject for their paintings: "direct suckling animals" (Romulus and Remus), "heteropaternal superfecundation" (mother: Leda, fathers: Zeus, the king of the Olympian gods, and Leda's husband, Tyndareus), and "twin-to-twin transfusion" in monozygotic twins (Jacob and Esau).

  6. Ancient "Observatories" - A Relevant Concept?

    Science.gov (United States)

    Belmonte, Juan Antonio

    It is quite common, when reading popular books on astronomy, to see a place referred to as "the oldest observatory in the world". In addition, numerous books on archaeoastronomy, of various levels of quality, frequently refer to the existence of "prehistoric" or "ancient" observatories when describing or citing monuments that were certainly not built with the primary purpose of observing the skies. Internet sources are also guilty of this practice. In this chapter, the different meanings of the word observatory will be analyzed, looking at how their significances can be easily confused or even interchanged. The proclaimed "ancient observatories" are a typical result of this situation. Finally, the relevance of the concept of the ancient observatory will be evaluated.

  7. Skeletal dysplasia in ancient Egypt.

    Science.gov (United States)

    Kozma, Chahira

    2008-12-01

    The ancient Egyptian civilization lasted for over 3000 years and ended in 30 BCE. Many aspects of ancient Egyptian culture, including the existence of skeletal dysplasias, and in particular achondroplasia, are well known through the monuments and records that survived until modern times. The hot and dry climate in Egypt allowed for the preservation of bodies and skeletal anomalies. The oldest dwarf skeleton, the Badarian skeleton (4500 BCE), possibly represents an epiphyseal disorder. Among the remains of dwarfs with achondroplasia from ancient Egypt (2686-2190 BCE), exists a skeleton of a pregnant female, believed to have died during delivery with a baby's remains in situ. British museums have partial skeletons of dwarfs with achondroplasia, humeri probably affected with mucopolysaccharidoses, and a skeleton of a child with osteogenesis imperfecta. Skeletal dysplasia is also found among royal remains. The mummy of the pharaoh Siptah (1342-1197 BCE) shows a deformity of the left leg and foot. A mummified fetus, believed to be the daughter of king Tutankhamun, has scoliosis, spina bifida, and Sprengel deformity. In 2006 I reviewed the previously existing knowledge of dwarfism in ancient Egypt. The purpose of this second historical review is to add to that knowledge with an expanded contribution. The artistic documentation of people with skeletal dysplasia from ancient Egypt is plentiful including hundreds of amulets, statues, and drawing on tomb and temple walls. Examination of artistic reliefs provides a glance of the role of people with skeletal dysplasia and the societal attitudes toward them. Both artistic evidence and moral teachings in ancient Egypt reveal wide integration of individuals with disabilities into the society.

  8. Neonate Human Remains: A Window of Opportunity to the Molecular Study of Ancient Syphilis

    Science.gov (United States)

    Montiel, Rafael; Solórzano, Eduvigis; Díaz, Nancy; Álvarez-Sandoval, Brenda A.; González-Ruiz, Mercedes; Cañadas, Mari Pau; Simões, Nelson; Isidro, Albert; Malgosa, Assumpció

    2012-01-01

    Ancient DNA (aDNA) analysis can be a useful tool in bacterial disease diagnosis in human remains. However, while the recovery of Mycobacterium spp. has been widely successful, several authors report unsuccessful results regarding ancient treponemal DNA, casting doubts on the usefulness of this technique for the diagnosis of ancient syphilis. Here, we present results from an analysis of four newborn specimens recovered from the crypt of “La Ermita de la Soledad” (XVI–XVII centuries), located in the province of Huelva in the southwest of Spain. We extracted and analyzed aDNA in three independent laboratories, following specific procedures generally practiced in the aDNA field, including cloning of the amplified DNA fragments and sequencing of several clones. This is the most ancient case, reported to date, from which detection of DNA from T. pallidum subspecies pallidum has been successful in more than one individual, and we put forward a hypothesis to explain this result, taking into account the course of the disease in neonate individuals. PMID:22567153

  9. Night blindness and ancient remedy

    Directory of Open Access Journals (Sweden)

    H.A. Hajar Al Binali

    2014-01-01

    Full Text Available The aim of this article is to briefly review the history of night blindness and its treatment from ancient times until the present. The old Egyptians, the Babylonians, the Greeks and the Arabs used animal liver for treatment and successfully cured the disease. The author had the opportunity to observe the application of the old remedy to a patient. Now we know what the ancients did not know, that night blindness is caused by Vitamin A deficiency and the animal liver is the store house for Vitamin A.

  10. Tuberculosis in ancient times

    Directory of Open Access Journals (Sweden)

    Louise Cilliers

    2008-09-01

    Full Text Available In spite of an array of effective antibiotics, tuberculosis is still very common in developing countries where overcrowding, malnutrition and poor hygienic conditions prevail. Over the past 30 years associated HIV infection has worsened the situation by increasing the infection rate and mortality of tuberculosis. Of those diseases caused by a single organism only HIV causes more deaths internationally than tuberculosis. The tubercle bacillus probably first infected man in Neolithic times, and then via infected cattle, but the causative Mycobacteriacea have been in existence for 300 million years. Droplet infection is the most common way of acquiring tuberculosis, although ingestion (e.g. of infected cows’ milk may occur. Tuberculosis probably originated in Africa. The earliest path gnomonic evidence of human tuberculosis in man was found in osteo-archaeological findings of bone tuberculosis (Pott’s disease of the spine in the skeleton of anEgyptian priest from the 21st Dynasty (approximately 1 000 BC. Suggestive but not conclusiveevidence of tuberculotic lesions had been found in even earlier skeletons from Egypt and Europe. Medical hieroglyphics from ancient Egypt are silent on the disease, which could be tuberculosis,as do early Indian and Chinese writings. The Old Testament refers to the disease schachapeth, translated as phthisis in the Greek Septuagint. Although the Bible is not specific about this condition, tuberculosis is still called schachapeth in modern Hebrew. In pre-Hippocratic Greece Homer did not mention phthisis, a word meaning non-specific wasting of the body. However. Alexander of Tralles (6th century BC seemed to narrow the concept down to a specific disease, and in the Hippocratic Corpus (5th-4th centuries BC phthisis can be recognised as tuberculosis. It was predominantly a respiratory disease commonly seen and considered to be caused by an imbalance of bodily humours. It was commonest in autumn, winter and spring

  11. Energy dependence of radioluminescence spectra from strontium titanate

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wyfemail@gmail.com [School of Science, China University of Geosciences, Beijing 100083 (China); Zhao, Y.; Zhang, Z.; Zhao, C.; Wu, X. [School of Science, China University of Geosciences, Beijing 100083 (China); Finch, A.A. [Department of Earth & Environmental Sciences, University of St. Andrews, Fife KY16 9AL (United Kingdom); Townsend, P.D. [Physics Building, University of Sussex, Brighton BN1 9QH (United Kingdom)

    2015-10-15

    X-ray excited luminescence spectra of strontium titanate are reported over the temperature range from 20 to 300 K. The range includes several crystalline phases, each with different emission spectra. The signals are thermally quenched above ~220 K. There are spectral shifts and intensity changes around the temperatures associated with phase changes and overall there are nominally three spectral emission bands. A remarkable observation is that at fixed lower temperatures the spectra undergo major changes with the energy of the X-rays. A possible cause of the effect is discussed in terms of inner shell excitation from the K shell of the strontium. Comparisons with thermoluminescence spectra from the strontium titanate are reported. - Highlights: • Radioluminescence spectra of SrTiO{sub 3} are reported from 20 to 300 K. • X-ray luminescence spectra depend on crystal phase. • Direct evidence for inner shell excitation of Sr controlling emission spectra.

  12. Studies of Ultracold Strontium Atoms in an Optical Dipole Trap

    Science.gov (United States)

    Traverso, A. J.; Martinez de Escobar, Y. N.; Mickelson, P. G.; Killian, T. C.

    2008-05-01

    We survey recent experiments with ultracold strontium performed in our group. Trapping and cooling occurs in three stages: successive magneto-optical traps (MOTs) operating on 461 nm and 689 nm transitions of strontium, respectively, are loaded to cool atoms to a temperature of 1 μK. Finally, atoms are loaded into a far-off-resonance optical dipole trap (ODT). We examine the loading characteristics, thermalization, and lifetime of atoms held within the ODT. We also perform spectroscopy of atoms held within the ODT. During laser cooling, we are able to manipulate the energy levels of the atoms and shelve them into metastable states using 707 nm and 3 μm lasers. These experiments reveal interesting physics of ultracold strontium.

  13. Microstructure of pre-sintered permanent magnetic strontium ferrite powder

    Institute of Scientific and Technical Information of China (English)

    YU Hongya; LIU Zhengyi; ZENG Dechang

    2006-01-01

    The microstructure and characteristics of pre-sintered strontium ferrite powderwere investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The present study shows that the pre-sintered strontium ferrite powder is provided with a certain particle size distribution, which results in high-density magnets. The strontium ferrite particle has a laminar hexagonal structure with a size similar to ferrite single domain. Ferric oxidephase due to an incomplete solid phase reaction in the first sintering is discovered, which will deteriorate the magnetic properties of ferrite magnet. In addition, the waste ferrite magnets with needle shape arranging along C axis in good order into the powders are found, which have no negative effects on finished product quality.

  14. Ligation Bias in Illumina Next-Generation DNA Libraries

    DEFF Research Database (Denmark)

    Seguin-Orlando, Andaine; Schubert, Mikkel; Clary, Joel;

    2013-01-01

    Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products,...

  15. Next-generation sequencing offers new insights into DNA degradation

    DEFF Research Database (Denmark)

    Overballe-Petersen, Søren; Orlando, Ludovic Antoine Alexandre; Willerslev, Eske

    2012-01-01

    The processes underlying DNA degradation are central to various disciplines, including cancer research, forensics and archaeology. The sequencing of ancient DNA molecules on next-generation sequencing platforms provides direct measurements of cytosine deamination, depurination and fragmentation r...

  16. Chromium isotopes in carbonates — A tracer for climate change and for reconstructing the redox state of ancient seawater

    DEFF Research Database (Denmark)

    Frei, Robert; Gaucher, Claudio; Døssing, Lasse Nørbye

    2011-01-01

    Strontium and carbon isotopes of marine carbonates are routinely applied for chemostratigraphic cross correlations of time-equivalent sedimentary sequences and for calibration of the compositional evolution of seawater throughout Earth's history, mainly for the purpose of reconstructing ancient.......708, and lower 147Sm/144Nd values of ~0.11, a source which is strongly affected by continentally derived input. Chromium isotopes provide a powerful tool for reconstructing the redox state of ancient seawater since positive values indicate that, at least locally, Neoproterozoic shallow ocean waters were......, glaciation acts as an amplifier of d53Cr signals. These signals in marine carbonates are a sensitive tracer for redox processes in the ocean and/or on land and have the potential to contribute significantly, in combination with the other commonly used isotopic tracers, to the reconstruction of climatic...

  17. Radiopaque Strontium Fluoroapatite Glass-Ceramics

    Science.gov (United States)

    Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

    2015-01-01

    The controlled precipitation of strontium fluoroapatite crystals was studied in four base glass compositions derived from the SiO2–Al2O3–Y2O3–SrO–Na2O–K2O/Rb2O/Cs2O–P2O5–F system. The crystal phase formation of these glasses and the main properties of the glass-ceramics, such as thermal and optical properties and radiopacity were compared with a fifth, a reference glass-ceramic. The reference glass-ceramic was characterized as Ca-fluoroapatite glass-ceramic. The four strontium fluoroapatite glass-ceramics showed the following crystal phases: (a) Sr5(PO4)3F – leucite, KAlSi2O6, (b) Sr5(PO4)3F – leucite, KAlSi2O6, and nano-sized NaSrPO4, (c) Sr5(PO4)3F – pollucite, CsAlSi2O6, and nano-sized NaSrPO4, and (d) Sr5(PO4)3F – Rb-leucite, RbAlSi2O6, and nano-sized NaSrPO4. The proof of crystal phase formation was possible by X-ray diffraction. The microstructures, which were studied using scanning electron microscopy, demonstrated a uniform distribution of the crystals in the glass matrix. The Sr-fluoroapatites were precipitated based on an internal crystallization process, and the crystals demonstrated a needle-like morphology. The study of the crystal growth of needle-like Sr-fluoroapatites gave a clear evidence of an Ostwald ripening mechanism. The formation of leucite, pollucite, and Rb-leucite was based on a surface crystallization mechanism. Therefore, a twofold crystallization mechanism was successfully applied to develop these types of glass-ceramics. The main focus of this study was the controlled development of glass-ceramics exhibiting high radiopacity in comparison to the reference glass-ceramic. This goal could be achieved with all four glass-ceramics with the preferred development of the Sr-fluoroapatite – pollucite-type glass-ceramic. In addition to this main development, it was possible to control the thermal properties. Especially the Rb-leucite containing glass-ceramic showed the highest coefficient of thermal

  18. Radiopaque Strontium Fluoroapatite Glass-Ceramics.

    Science.gov (United States)

    Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

    2015-01-01

    The controlled precipitation of strontium fluoroapatite crystals was studied in four base glass compositions derived from the SiO2-Al2O3-Y2O3-SrO-Na2O-K2O/Rb2O/Cs2O-P2O5-F system. The crystal phase formation of these glasses and the main properties of the glass-ceramics, such as thermal and optical properties and radiopacity were compared with a fifth, a reference glass-ceramic. The reference glass-ceramic was characterized as Ca-fluoroapatite glass-ceramic. The four strontium fluoroapatite glass-ceramics showed the following crystal phases: (a) Sr5(PO4)3F - leucite, KAlSi2O6, (b) Sr5(PO4)3F - leucite, KAlSi2O6, and nano-sized NaSrPO4, (c) Sr5(PO4)3F - pollucite, CsAlSi2O6, and nano-sized NaSrPO4, and (d) Sr5(PO4)3F - Rb-leucite, RbAlSi2O6, and nano-sized NaSrPO4. The proof of crystal phase formation was possible by X-ray diffraction. The microstructures, which were studied using scanning electron microscopy, demonstrated a uniform distribution of the crystals in the glass matrix. The Sr-fluoroapatites were precipitated based on an internal crystallization process, and the crystals demonstrated a needle-like morphology. The study of the crystal growth of needle-like Sr-fluoroapatites gave a clear evidence of an Ostwald ripening mechanism. The formation of leucite, pollucite, and Rb-leucite was based on a surface crystallization mechanism. Therefore, a twofold crystallization mechanism was successfully applied to develop these types of glass-ceramics. The main focus of this study was the controlled development of glass-ceramics exhibiting high radiopacity in comparison to the reference glass-ceramic. This goal could be achieved with all four glass-ceramics with the preferred development of the Sr-fluoroapatite - pollucite-type glass-ceramic. In addition to this main development, it was possible to control the thermal properties. Especially the Rb-leucite containing glass-ceramic showed the highest coefficient of thermal expansion (CTE). These

  19. ADSORPTION OF STRONTIUM IONS FROM WATER ON MODIFIED ACTIVATED CARBONS

    Directory of Open Access Journals (Sweden)

    Mihai Ciobanu

    2016-12-01

    Full Text Available Adsorption of strontium ions from aqueous solutions on active carbons CAN-7 and oxidized CAN-8 has been studied. It has been found that allure of the adsorption isotherms for both studied active carbons are practically identical. Studies have shown that the adsorption isotherms for strontium ions from aqueous solutions are well described by the Langmuir and Dubinin-Radushkevich equations, respectively. The surface heterogeneity of activated carbons CAN-7 and oxidized CAN-8 has been assessed by using Freundlich equation.

  20. Strontium cobaltite oxygen sponge catalyst and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Nyung; Jeen, Hyoungjeen; Choi, Woo Seok; Biegalski, Michael; Folkman, Chad M.; Tung, I-Cheng; Fong, Dillon D.; Freeland, John W.; Shin, Dongwon; Ohta, Hiromichi; Chisholm, Matthew F.

    2017-01-24

    Rapid, reversible redox activity may be accomplished at significantly reduced temperatures, as low as about 200.degree. C., from epitaxially stabilized, oxygen vacancy ordered SrCoO.sub.2.5 and thermodynamically unfavorable perovskite SrCoO.sub.3-.delta.. The fast, low temperature redox activity in SrCoO.sub.3-.delta. may be attributed to a small Gibbs free energy difference between the two topotactic phases. Epitaxially stabilized thin films of strontium cobaltite provide a catalyst adapted to rapidly transition between oxidation states at substantially low temperatures. Methods of transitioning a strontium cobaltite catalyst from a first oxidation state to a second oxidation state are described.

  1. Modified strontium titanates: From defect chemistry to SOFC anodes

    DEFF Research Database (Denmark)

    Verbraeken, M.C.; Ramos, Tania; Agersted, Karsten

    2015-01-01

    and amount of substituent, but also perovskite defect chemistry, distinguishing between A-site deficiency (A1-xBO3) and cation-stoichiometry (ABO3+δ). Literature suggests distinct differences in the materials properties between the latter two compositional approaches. After discussing the defect chemistry...... of modified strontium titanates, this paper reviews three different A-site deficient donor (La, Y, Nb) substituted strontium titanates for their electrical behaviour and fuel cell performance. Promising performances in both electrolyte as well as anode supported cell designs have been obtained, when using...

  2. Crystal structure of strontium dinickel iron orthophosphate

    Directory of Open Access Journals (Sweden)

    Said Ouaatta

    2015-10-01

    Full Text Available The title compound, SrNi2Fe(PO43, synthesized by solid-state reaction, crystallizes in an ordered variant of the α-CrPO4 structure. In the asymmetric unit, two O atoms are in general positions, whereas all others atoms are in special positions of the space group Imma: the Sr cation and one P atom occupy the Wyckoff position 4e (mm2, Fe is on 4b (2/m, Ni and the other P atom are on 8g (2, one O atom is on 8h (m and the other on 8i (m. The three-dimensional framework of the crystal structure is built up by [PO4] tetrahedra, [FeO6] octahedra and [Ni2O10] dimers of edge-sharing octahedra, linked through common corners or edges. This structure comprises two types of layers stacked alternately along the [100] direction. The first layer is formed by edge-sharing octahedra ([Ni2O10] dimer linked to [PO4] tetrahedra via common edges while the second layer is built up from a strontium row followed by infinite chains of alternating [PO4] tetrahedra and FeO6 octahedra sharing apices. The layers are held together through vertices of [PO4] tetrahedra and [FeO6] octahedra, leading to the appearance of two types of tunnels parallel to the a- and b-axis directions in which the Sr cations are located. Each Sr cation is surrounded by eight O atoms.

  3. The eye and its diseases in Ancient Egypt

    DEFF Research Database (Denmark)

    Andersen, S. Ry

    1997-01-01

    Ophthalmology, History of ophthalmology, eyes in the Ancient Egypt, eye disease in Ancient Egypt, porotic hyperostosis, mummification......Ophthalmology, History of ophthalmology, eyes in the Ancient Egypt, eye disease in Ancient Egypt, porotic hyperostosis, mummification...

  4. The ancient art of memory.

    Science.gov (United States)

    Hobson, Allan

    2013-12-01

    Revision of Freud's theory requires a new way of seeking dream meaning. With the idea of elaborative encoding, Sue Llewellyn has provided a method of dream interpretation that takes into account both modern sleep science and the ancient art of memory. Her synthesis is elegant and compelling. But is her hypothesis testable?

  5. Ancient medicine--a review.

    Science.gov (United States)

    Zuskin, Eugenija; Lipozencić, Jasna; Pucarin-Cvetković, Jasna; Mustajbegović, Jadranka; Schachter, Neil; Mucić-Pucić, Branka; Neralić-Meniga, Inja

    2008-01-01

    Different aspects of medicine and/or healing in several societies are presented. In the ancient times as well as today medicine has been closely related to magic, science and religion. Various ancient societies and cultures had developed different views of medicine. It was believed that a human being has two bodies: a visible body that belongs to the earth and an invisible body of heaven. In the earliest prehistoric days, a different kind of medicine was practiced in countries such as Egypt, Greece, Rome, Mesopotamia, India, Tibet, China, and others. In those countries, "medicine people" practiced medicine from the magic to modern physical practices. Medicine was magical and mythological, and diseases were attributed mostly to the supernatural forces. The foundation of modern medicine can be traced back to ancient Greeks. Tibetan culture, for instance, even today, combines spiritual and practical medicine. Chinese medicine developed as a concept of yin and yang, acupuncture and acupressure, and it has even been used in the modern medicine. During medieval Europe, major universities and medical schools were established. In the ancient time, before hospitals had developed, patients were treated mostly in temples.

  6. Thermal effects on rare earth element and strontium isotope chemistry in single conodont elements

    Science.gov (United States)

    Armstrong, H. A.; Pearson, D. G.; Griselin, M.

    2001-02-01

    A low-blank, high sensitivity isotope dilution, ICP-MS analytical technique has been used to obtain REE abundance data from single conodont elements weighing as little as 5 μg. Sr isotopes can also be measured from the column eluants enabling Sr isotope ratios and REE abundance to be determined from the same dissolution. Results are comparable to published analyses comprising tens to hundreds of elements. To study the effects of thermal metamorphism on REE and strontium mobility in conodonts, samples were selected from a single bed adjacent to a basaltic dyke and from the internationally used colour alteration index (CAI) "standard set." Our analyses span the range of CAI 1 to 8. Homogeneous REE patterns, "bell-shaped" shale-normalised REE patterns are observed across the range of CAI 1 to 6 in both sample sets. This pattern is interpreted as the result of adsorption during early diagenesis and could reflect original seawater chemistry. Above CAI 6 REE patterns become less predictable and perturbations from the typical REE pattern are likely to be due to the onset of apatite recrystallisation. Samples outside the contact aureole of the dyke have a mean 87Sr/ 86Sr ratio of 0.708165, within the broad range of published mid-Carboniferous seawater values. Our analysis indicates conodonts up to CAI 6 record primary geochemical signals that may be a proxy for ancient seawater.

  7. Molecular analysis of skeletal tuberculosis in an ancient Egyptian population.

    Science.gov (United States)

    Zink, A; Haas, C J; Reischl, U; Szeimies, U; Nerlich, A G

    2001-04-01

    A paleomicrobiological study was performed on 37 skeletal tissue specimens from cadavers in the necropolis of Thebes-West, Upper Egypt, (2120-500 BC) and four from the necropolis of Abydos (3000 BC). The subjects had typical macromorphological evidence of osseous tuberculosis (n = 3), morphological alterations that were not specific, but probably resulted from tuberculosis (n = 17), or were without morphological osseous changes (n = 21). DNA was extracted from these bone samples and amplified by PCR with a primer pair that recognised the Mycobacterium tuberculosis complex insertion sequence IS6110. To confirm specificity of the analysis, the amplification products of several samples were subjected to restriction enzyme digestion, or direct sequencing, or both. In 30 of the 41 cases analysed, ancient DNA was demonstrated by amplification by the presence of the human beta-actin or the amelogenin gene and nine of these cases were positive for M. tuberculosis DNA. The results were confirmed by restriction endonuclease digestion and sequencing. A positive result for M. tuberculosis DNA was seen in two of the three cases with typical morphological signs of tuberculosis and amplifiable DNA, in five of 13 non-specific, but probable cases (including two cases from c. 3000 BC), but also in two of 14 cases without pathological bone changes. These observations confirm that tuberculosis may be diagnosed unequivocally in skeletal material from ancient Egypt, even dating back to c. 3000 BC. As a positive molecular reaction was observed in most of the typical cases of skeletal tuberculosis, in about one-third of non-specific, but probable tuberculous osseous changes and, surprisingly, in about one-seventh of unremarkable samples, this suggests that infection with M. tuberculosis was relatively frequent in ancient Egypt.

  8. A Huge Ancient Schwannoma of the Epiglottis.

    Science.gov (United States)

    Lee, Dong Hoon; Kim, Jo Heon; Yoon, Tae Mi; Lee, Joon Kyoo; Lim, Sang Chul

    2016-03-01

    Ancient schwannoma of the epiglottis is extremely rare. The authors report the first case of a patient with a huge ancient schwannoma of the epiglottis. Clinicians should consider the possibility that ancient schwannoma may originate in the epiglottis mimicking the other more frequently observed lesions.

  9. The effects of strontium ranelate treatment on ovariectomized Sprague-Dawley rat tibia

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y. [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Jin, W. [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Wang, C.; Yang, M. [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Shen, H. [Institute of Modern Physics, Fudan University, Shanghai 200433 (China)], E-mail: haoshen@fudan.edu.cn; Eisa, M.H. [Department of Physics, College of Science, Sudan University of Science and Technology, Box 407, Khartoum 111113 (Sudan); Mi, Y. [Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2009-06-15

    Micro Proton Induced X-ray Emission (micro-PIXE) technique was used to study the effect of strontium ranelate on osteoporosis resulted from estrogen deficiency. The contents of calcium and strontium in tibia, as well as calcium distribution for structural determination were investigated. Three groups of tibia samples were respectively taken from three groups of female Sprague-Dawley (S.D.) rats, i.e. control, ovariectomized and ovariectomized followed strontium ranelate treatment. It was found that the strontium content was decreasing in the bone from ovariectomized rat compared with that in control, but significantly increasing in the bone from strontium ranelate treated ovariectomized rat. Our study showed that strontium content is a feasible parameter for the diagnosis of osteoporosis caused by estrogen deficiency. Strontium ranelate is an effective antiosteoporosis chemical to rebuild the bone structure and prevent deterioration of bone strength as well.

  10. Variation in strontium isotope ratios of archaeological fauna in the Midwestern United States: a preliminary study

    Science.gov (United States)

    Hedman, Kristin M.; Curry, B. Brandon; Johnson, Thomas M.; Fullagar, Paul D.; Emerson, Thomas E.

    2009-01-01

    Strontium isotope values (87Sr/86Sr) in bone and tooth enamel have been used increasingly to identify non-local individuals within prehistoric human populations worldwide. Archaeological research in the Midwestern United States has increasingly highlighted the role of population movement in affecting interregional cultural change. However, the comparatively low level of geologic variation in the Midwestern United States might suggest a corresponding low level of strontium variation, and calls into question the sensitivity of strontium isotopes to identify non-local individuals in this region. Using strontium isotopes of archaeological fauna, we explore the degree of variability in strontium ratios across this region. Our results demonstrate measurable variation in strontium ratios and indicate the potential of strontium analysis for addressing questions of origin and population movement in the Midwestern United States.

  11. The effects of strontium ranelate treatment on ovariectomized Sprague-Dawley rat tibia

    Science.gov (United States)

    Zheng, Y.; Jin, W.; Wang, C.; Yang, M.; Shen, H.; Eisa, M. H.; Mi, Y.

    2009-06-01

    Micro Proton Induced X-ray Emission (micro-PIXE) technique was used to study the effect of strontium ranelate on osteoporosis resulted from estrogen deficiency. The contents of calcium and strontium in tibia, as well as calcium distribution for structural determination were investigated. Three groups of tibia samples were respectively taken from three groups of female Sprague-Dawley (S.D.) rats, i.e. control, ovariectomized and ovariectomized followed strontium ranelate treatment. It was found that the strontium content was decreasing in the bone from ovariectomized rat compared with that in control, but significantly increasing in the bone from strontium ranelate treated ovariectomized rat. Our study showed that strontium content is a feasible parameter for the diagnosis of osteoporosis caused by estrogen deficiency. Strontium ranelate is an effective antiosteoporosis chemical to rebuild the bone structure and prevent deterioration of bone strength as well.

  12. Laser sources for precision spectroscopy on atomic strontium.

    Science.gov (United States)

    Poli, N; Ferrari, G; Prevedelli, M; Sorrentino, F; Drullinger, R E; Tino, G M

    2006-04-01

    We present a new laser setup designed for high-precision spectroscopy on laser cooled atomic strontium. The system, which is entirely based on semiconductor laser sources, delivers 200 mW at 461 nm for cooling and trapping atomic strontium from a thermal source, 4 mW at 497 nm for optical pumping from the metastable P23 state, 12 mW at 689 nm on linewidth less than 1 kHz for second-stage cooling of the atomic sample down to the recoil limit, 1.2 W at 922 nm for optical trapping close to the "magic wavelength" for the 0-1 intercombination line at 689 nm. The 689 nm laser was already employed to perform a frequency measurement of the 0-1 intercombination line with a relative accuracy of 2.3 x 10(-11), and the ensemble of laser sources allowed the loading in a conservative dipole trap of multi-isotopes strontium mixtures. The simple and compact setup developed represents one of the first steps towards the realization of a transportable optical standards referenced to atomic strontium.

  13. Laser-induced collisional autoionization in europium and strontium atoms.

    Science.gov (United States)

    Buffa, R

    1995-01-15

    An experiment that involves laser-induced collisional autoionization in europium and strontium atoms is proposed and the spectral line shape of the cross section is calculated on the basis of data available in the literature. The feasibility of the experiment both in oven cells and in a crossed-atomic-beam geometry is discussed.

  14. Effects of strontium ranelate on spinal osteoarthritis progression

    DEFF Research Database (Denmark)

    Bruyere, O; Delferriere, D; Roux, C

    2008-01-01

    OBJECTIVE: The aim of this study was to determine whether a 3-year treatment with strontium ranelate could delay the progression of spinal osteoarthritis (OA). METHODS: This study was a post-hoc analysis of pooled data from the Spinal Osteoporosis Therapeutic Intervention (SOTI) and TReatment...

  15. Vibrational spectra of the two hydrates of strontium oxalate.

    Science.gov (United States)

    D'Antonio, Maria C; Torres, María M; Palacios, Daniel; González-Baró, Ana C; Baran, Enrique J

    2015-02-25

    The infrared and Raman spectra of the two hydrates of strontium oxalate, SrC2O4⋅H2O and SrC2O4⋅2H2O, were recorded and discussed on the basis of their structural peculiarities and in comparison with the spectra of the related calcium oxalates and other previously investigated metallic oxalates.

  16. Strontium hydrogeochemistry of thermal groundwaters from Baikal and Xinzhou

    Institute of Scientific and Technical Information of China (English)

    王焰新; 沈照理

    2001-01-01

    This paper reports our work on the strontium hydrogeochemistry of thermal groundwa-ters in the Baikal Rift System (BRS) in Russia and Mongolia and the Xinzhou basin of the Shanxi Rift System (SRS) in northern China. Though similar in geological background, groundwaters from the BRS and the Xinzhou basin have different strontium isotope compositions. Both the strontium contents and the 87Sr/86Sr ratios of thermal water samples from Xinzhou are higher than those of most samples from Baikal. The major reason is the difference in hostrock geochemistry. The hos-trocks of the Xinzhou waters are Archaean metamorphic rocks, while those of the Baikal waters except the Kejielikov spring are Proterozoic or younger rocks. In the study areas, cold groundwaters usually show lower 87Sr/86Sr ratio due to shorter water-rock interaction history and lower equilibration degree. Strontium hydrogeochemistry often provides important information about mixing processes. Ca/Sr ratio can be used as an important hydrogeochemical pa

  17. Heavy ion recoil spectrometry of barium strontium titanate films

    Science.gov (United States)

    Stannard, W. B.; Johnston, P. N.; Walker, S. R.; Bubb, I. F.; Scott, J. F.; Cohen, D. D.; Dytlewski, N.; Martin, J. W.

    1995-05-01

    Thin films of barium strontium titanate have been analysed using heavy ion recoil spectrometry with 77 and 98 MeV 127I ions at the new heavy ion recoil facility at ANSTO, Lucas Heights. New calibration procedures have been developed for quantitative analysis. Energy spectra for each of the elements present reveal interdiffusion that was not previously known.

  18. Membrane-based separation technologies for cesium, strontium, and technetium

    Energy Technology Data Exchange (ETDEWEB)

    Kafka, T.

    1996-10-01

    This work is one of two parallel projects that are part of an ESP task to develop high-capacity, selective, solid extractants for cesium, strontium, and technetium from nuclear wastes. In this subtask, Pacific Northwest National Laboratory (PNNL) is collaborating with 3M, St. Paul, Minnesota, working in cooperation with IBC Advanced Technologies, American Fork, Utah.

  19. Thermal behaviour of strontium tartrate single crystals grown in gel

    Indian Academy of Sciences (India)

    M H Rahimkutty; K Rajendra Babu; K Sreedharan Pillai; M R Sudarsana Kumar; C M K Nair

    2001-04-01

    Thermal behaviour of strontium tartrate crystals grown with the aid of sodium metasilicate gel is investigated using thermogravimetry (TG) and differential thermal analysis (DTA). Effect of magnetic field and dopant (Pb)2+ on the crystal stability is also studied using thermal analysis. This study reveals that water molecules are locked up in the lattice with different strengths in the grown crystals.

  20. Single gene retrieval from thermally degraded DNA

    Indian Academy of Sciences (India)

    Lianwen Zhang; Lianwen Zhang

    2005-12-01

    To simulate single gene retrieval from ancient DNA, several related factors have been investigated. By monitoring a 889 bp polymerase chain reaction (PCR) product and genomic DNA degradation, we find that heat and oxygen (especially heat) are both crucial factors influencing DNA degradation. The heat influence, mainly represented by temperature and heating time, affects the DNA degradation via DNA depurination followed by cleavage of nearby phosphodiesters. The heating time influence is temperature-dependent. By reactive oxygen species (ROS) scavenging and 1,3-diphenyl-isobenzofuran (DPBF) bleaching experiments the influence of oxygen on DNA thermal degradation was shown to occur via a singlet oxygen pathway. A comparative study of the thermal degradation of cellular DNA and isolated DNA showed that cellular lipids can aggravate DNA thermal degradation. These results confirm the possibility of gene amplification from thermally degraded DNA. They can be used to evaluate the feasibility of the retrieval of single gene from ancient remains.

  1. LUCApedia: a database for the study of ancient life.

    Science.gov (United States)

    Goldman, Aaron David; Bernhard, Tess M; Dolzhenko, Egor; Landweber, Laura F

    2013-01-01

    Organisms represented by the root of the universal evolutionary tree were most likely complex cells with a sophisticated protein translation system and a DNA genome encoding hundreds of genes. The growth of bioinformatics data from taxonomically diverse organisms has made it possible to infer the likely properties of early life in greater detail. Here we present LUCApedia, (http://eeb.princeton.edu/lucapedia), a unified framework for simultaneously evaluating multiple data sets related to the Last Universal Common Ancestor (LUCA) and its predecessors. This unification is achieved by mapping eleven such data sets onto UniProt, KEGG and BioCyc IDs. LUCApedia may be used to rapidly acquire evidence that a certain gene or set of genes is ancient, to examine the early evolution of metabolic pathways, or to test specific hypotheses related to ancient life by corroborating them against the rest of the database.

  2. Molecular analysis of ancient caries.

    Science.gov (United States)

    Simón, Marc; Montiel, Rafael; Smerling, Andrea; Solórzano, Eduvigis; Díaz, Nancy; Álvarez-Sandoval, Brenda A; Jiménez-Marín, Andrea R; Malgosa, Assumpció

    2014-09-01

    An 84 base pair sequence of the Streptococcus mutans virulence factor, known as dextranase, has been obtained from 10 individuals from the Bronze Age to the Modern Era in Europe and from before and after the colonization in America. Modern samples show four polymorphic sites that have not been found in the ancient samples studied so far. The nucleotide and haplotype diversity of this region have increased over time, which could be reflecting the footprint of a population expansion. While this segment has apparently evolved according to neutral evolution, we have been able to detect one site that is under positive selection pressure both in present and past populations. This study is a first step to study the evolution of this microorganism, analysed using direct evidence obtained from ancient remains.

  3. Models of ancient sound vases

    Science.gov (United States)

    Bruel, Per V.

    2002-11-01

    Models were made of vases described by Vitruvius in Rome in about the year 70 A.D. and of sound vases (lydpotter) placed in Danish churches from 1100-1300 A.D. Measurements of vase's resonant frequencies and damping (reradiation) verified that the model vases obeyed expected physical rules. It was concluded that the excellent acoustical quality of many ancient Greek and Roman theaters cannot be ascribed to the vases placed under their seats. This study also found that sound vases placed in Nordic churches could not have shortened the reverberation time because there are far too few of them. Moreover, they could not have covered a broad frequency range. It remains a mystery why vases were installed under the seats of ancient Greek theaters and why, 1000 years later, Danes placed vases in their churches.

  4. Identifications of ancient Egyptian royal mummies from the 18th Dynasty reconsidered.

    Science.gov (United States)

    Habicht, M E; Bouwman, A S; Rühli, F J

    2016-01-01

    For centuries, ancient Egyptian Royal mummies have drawn the attention both of the general public and scientists. Many royal mummies from the New Kingdom have survived. The discoveries of the bodies of these ancient rulers have always sparked much attention, yet not all identifications are clear even nowadays. This study presents a meta-analysis to demonstrate the difficulties in identifying ancient Egyptian royal mummies. Various methods and pitfalls in the identification of the Pharaohs are reassessed since new scientific methods can be used, such as ancient DNA-profiling and CT-scanning. While the ancestors of Tutankhamun have been identified, some identities are still highly controversial (e.g., the mystery of the KV-55 skeleton, recently most likely identified as the genetic father of Tutankhamun). The meta-analysis confirms the suggested identity of some mummies (e.g., Amenhotep III, Thutmosis IV, and Queen Tjye).

  5. Splendid Arts Fram Ancient Capitals

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    IT was in the golden autumn in Beijing, when the sky was high and the air clear, that I hurried to Zhongshan Park to witness the display of the songs and dances of the seven Chinese ancient capitals. The flower beds arranged for the celebration of National Day were still there and the colorful blooms looked especially bright in the sunshine. The seven cities which have served as capitals in Chinese history are Beijing,

  6. Psychiatric Thoughts in Ancient India

    Directory of Open Access Journals (Sweden)

    Ravi Abhyankar

    2015-01-01

    Full Text Available A review of the literature regarding psychiatric thoughts in ancient India is attempted. Besides interesting reading, many of the concepts are still relevant and can be used in day-to-day practice especially towards healthy and happy living. Certain concepts are surprisingly contemporary and valid today. They can be used in psychotherapy and counselling and for promoting mental health. However, the description and classification of mental illness is not in tune with modern psychiatry.

  7. Nanoscience of an ancient pigment.

    Science.gov (United States)

    Johnson-McDaniel, Darrah; Barrett, Christopher A; Sharafi, Asma; Salguero, Tina T

    2013-02-06

    We describe monolayer nanosheets of calcium copper tetrasilicate, CaCuSi(4)O(10), which have strong near-IR luminescence and are amenable to solution processing methods. The facile exfoliation of bulk CaCuSi(4)O(10) into nanosheets is especially surprising in view of the long history of this material as the colored component of Egyptian blue, a well-known pigment from ancient times.

  8. Microwave-assisted fabrication of strontium doped apatite coating on Ti6Al4V

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huan, E-mail: huanzhou@cczu.edu.cn [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164 (China); Kong, Shiqin [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164 (China); School of Materials Science and Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Pan, Yan; Zhang, Zhiguo [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164 (China); Deng, Linhong, E-mail: dlh@cczu.edu.cn [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu 213164 (China)

    2015-11-01

    Strontium has been shown to be a beneficial dopant to calcium phosphates when incorporated at nontoxic level. In the present work we studied the possibility of solution derived doping strontium into calcium phosphate coatings on titanium alloy Ti6Al4V based implants by a recently reported microwave-assisted method. By using this method strontium doped calcium phosphate nuclei were deposited to pretreated titanium alloy surface dot by dot to compose a crack-free coating layer. The presence of strontium in solution led to reduced roughness of the coating and finer nucleus size formed. In vitro study found that proliferation and differentiation of osteoblast cells seeded on the coating were influenced by strontium content in coatings, showing an increasing followed by a decreasing behavior with increasing substitution of calcium by strontium. It is suggested that this new microwave-assisted strontium doped calcium phosphate coatings may have great potential in implant modification. - Highlights: • Strontium doped calcium phosphate coating is deposited with microwave irradiation. • Increase of strontium reduces coating roughness and results in finer nucleus size. • Proliferation and differentiation of osteoblasts depend on doped strontium content.

  9. Physico-chemical and in vitro biological evaluation of strontium/calcium silicophosphate glass.

    Science.gov (United States)

    Hesaraki, Saeed; Alizadeh, Masoud; Nazarian, Hamid; Sharifi, Davood

    2010-02-01

    Strontium is known to reduce bone resorption and stimulate bone formation. Incorporation of strontium into calcium phosphate bioceramics has been widely reported. In this work, calcium and calcium/strontium silicophosphate glasses were synthesized from the sol-gel process and their rheological, thermal, and in vitro biological properties were studied and compared to each other. The results showed that the gel viscosity and thus the rate of gel formation increased by using strontium in glass composition and by increasing aging temperature. In strontium-containing glass, the crystallization temperature increased and the type of the crystallized phase was different to that of strontium-free glass. Both glasses favored precipitation of calcium phosphate layer when they were soaked in simulated body fluid; however strontium seemed to retard the rate of precipitation slightly. The in vitro biodegradation rate of the strontium/calcium silicophosphate glass was higher than that of strontium-free one. The cell culture experiments carried out using rat calvaria osteoblasts showed that the incorporation of strontium into the glass composition stimulated proliferation of the cells and enhanced their alkaline phosphatase activity, depending on cell culture period.

  10. Novel Pharmaceutical Strontium Malonate Influence on Calcium and Strontium Adsorption by Dog Femur and by Dog Teeth in a Four-Week Toxicity Study

    DEFF Research Database (Denmark)

    Raffalt, Anders Christer; Christgau, Stephan; Andersen, Jens Enevold Thaulov

    Strontium is known to have a positive effect on bone by concomitantly increasing bone formation while decreasing bone resorption thereby providing a sustained skeletal benefit. Strontium malonate is being developed as a novel orally available pharmaceutical for the treatment and prevention...

  11. Determination of strontium and simultaneous determination of strontium oxide, magnesium oxide and calcium oxide content of Portland cement by derivative ratio spectrophotometry.

    Science.gov (United States)

    Idriss, K A; Sedaira, H; Ahmed, S S

    2009-04-15

    A derivative spectrophotometric method has been developed for the determination of strontium in Portland cement. The method is applied successfully for the simultaneous determination of SrO, MgO and CaO. It is based on the use of Alizarin Complexone (AC) as a complexing agent and measurement of the derivative ratio spectra of the analytes. Interferences of manganese(II) and zinc(II) were eliminated by precipitation. The validity of the method was examined by analyzing several Standard Reference Material (SRM) Portland cement samples. The strontium complex formed at pH 9.5 allows precise and accurate determination of strontium over the concentration range of 1.5-18 mg L(-1) of strontium. The MDL (at 95% confidence level) was found to be 25 ng mL(-1) for strontium in National Institute of Standards and Technology (NIST) cement samples using the proposed method.

  12. Optical lattice clock with Strontium atoms; Horloge a reseau optique a atomes de strontium

    Energy Technology Data Exchange (ETDEWEB)

    Baillard, X

    2008-01-15

    This thesis presents the latest achievements regarding the optical lattice clock with Strontium atoms developed at LNE-SYRTE. After a review of the different types of optical clocks that are currently under development, we stress on the concept of optical lattice clock which was first imagined for Sr{sup 87} using the {sup 1}S{sub 0} {yields} {sup 3}P{sub 0} transition. We exhibit the features of this atom, in particular the concept of magic wavelength for the trap, and the achievable performances for this kind of clock. The second part presents the experimental aspects, insisting particularly on the ultra-stable laser used for the interrogation of the atoms which is a central part of the experiment. Among the latest improvements, an optical pumping phase and an interrogation phase using a magnetic field have been added in order to refine the evaluation of the Zeeman effect. Finally, the last part presents the experimental results. The last evaluation of the clock using Sr{sup 87} atoms allowed us to reach a frequency accuracy of 2.6*10{sup -15} and a measurement in agreement with the one made at JILA (Tokyo university) at the 10{sup -15} level. On another hand, thanks to recent theoretical proposals, we made a measurement using the bosonic isotope Sr{sup 88} by adapting the experimental setup. This measurement represents the first evaluation for this type of clock, with a frequency accuracy of 7*10{sup -14}. (author)

  13. Multiple maternal origins of native modern and ancient horse populations in China.

    Science.gov (United States)

    Lei, C Z; Su, R; Bower, M A; Edwards, C J; Wang, X B; Weining, S; Liu, L; Xie, W M; Li, F; Liu, R Y; Zhang, Y S; Zhang, C M; Chen, H

    2009-12-01

    To obtain more knowledge of the origin and genetic diversity of domestic horses in China, this study provides a comprehensive analysis of mitochondrial DNA (mtDNA) D-loop sequence diversity from nine horse breeds in China in conjunction with ancient DNA data and evidence from archaeological and historical records. A 247-bp mitochondrial D-loop sequence from 182 modern samples revealed a total of 70 haplotypes with a high level of genetic diversity. Seven major mtDNA haplogroups (A-G) and 16 clusters were identified for the 182 Chinese modern horses. In the present study, nine 247-bp mitochondrial D-loop sequences of ancient remains of Bronze Age horse from the Chifeng region of Inner Mongolia in China (c. 4000-2000a bp) were used to explore the origin and diversity of Chinese modern horses and the phylogenetic relationship between ancient and modern horses. The nine ancient horses carried seven haplotypes with rich genetic diversity, which were clustered together with modern individuals among haplogroups A, E and F. Modern domestic horse and ancient horse data support the multiple origins of domestic horses in China. This study supports the argument that multiple successful events of horse domestication, including separate introductions of wild mares into the domestic herds, may have occurred in antiquity, and that China cannot be excluded from these events. Indeed, the association of Far Eastern mtDNA types to haplogroup F was highly significant using Fisher's exact test of independence (P = 0.00002), lending support for Chinese domestication of this haplogroup. High diversity and all seven mtDNA haplogroups (A-G) with 16 clusters also suggest that further work is necessary to shed more light on horse domestication in China.

  14. Strontium Adsorption and Desorption Reactions in Model Drinking Water Distribution Systems

    Science.gov (United States)

    2014-02-04

    Strontium K-edge spectra for bulk XANES sr’+ standards and for the iron corrosion product samples representing (a) chlorine and chloramine simulated...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 11-04-2014 Journal Article Strontium adsorption and desorption reactions in model... strontium (Sr2+) adsorption to and desorption from iron corrosion products were examined in two model drinking water distribution systems (DWDS

  15. Molecular identification of bacteria by total sequence screening: determining the cause of death in ancient human subjects.

    Directory of Open Access Journals (Sweden)

    Catherine Thèves

    Full Text Available Research of ancient pathogens in ancient human skeletons has been mainly carried out on the basis of one essential historical or archaeological observation, permitting specific pathogens to be targeted. Detection of ancient human pathogens without such evidence is more difficult, since the quantity and quality of ancient DNA, as well as the environmental bacteria potentially present in the sample, limit the analyses possible. Using human lung tissue and/or teeth samples from burials in eastern Siberia, dating from the end of 17(th to the 19(th century, we propose a methodology that includes the: 1 amplification of all 16S rDNA gene sequences present in each sample; 2 identification of all bacterial DNA sequences with a degree of identity ≥ 95%, according to quality criteria; 3 identification and confirmation of bacterial pathogens by the amplification of the rpoB gene; and 4 establishment of authenticity criteria for ancient DNA. This study demonstrates that from teeth samples originating from ancient human subjects, we can realise: 1 the correct identification of bacterial molecular sequence signatures by quality criteria; 2 the separation of environmental and pathogenic bacterial 16S rDNA sequences; 3 the distribution of bacterial species for each subject and for each burial; and 4 the characterisation of bacteria specific to the permafrost. Moreover, we identified three pathogens in different teeth samples by 16S rDNA sequence amplification: Bordetella sp., Streptococcus pneumoniae and Shigella dysenteriae. We tested for the presence of these pathogens by amplifying the rpoB gene. For the first time, we confirmed sequences from Bordetella pertussis in the lungs of an ancient male Siberian subject, whose grave dated from the end of the 17(th century to the early 18(th century.

  16. Migration Behaviour of Strontium in Czech Bentonite Clay

    Directory of Open Access Journals (Sweden)

    Lucie Baborova

    2016-09-01

    Full Text Available The study deals with sorption and diffusion behaviour of strontium in Czech bentonite B75. The study is a part of a research on reactive transport of radioactive contaminants in barrier materials of a deep geological repository of radioactive waste in the Czech Republic. Series of sorption and diffusion experiments with Sr and non-activated Ca bentonite B75 produced in the Czech Republic were performed in two background solutions (CaCl2 and NaCl. On the basis of sorption batch experiments the kinetics of strontium sorption on bentonite was assessed and the sorption isotherms for various experimental conditions were obtained. As a result of performed diffusion experiments the parameters of diffusion (i.e. effective diffusion coefficient De and apparent diffusion coefficient Da were determined. The observed discrepancies between sorption characteristics obtained from the sorption and diffusion experiments are discussed.

  17. Growth of strontium oxalate crystals in agar–agar gel

    Indian Academy of Sciences (India)

    P V Dalal; K B Saraf

    2011-04-01

    Single crystals of strontium oxalate have been grown by using strontium chloride and oxalic acid in agar–agar gel media at ambient temperature. Different methods for growing crystals were adopted. The optimum conditions were employed in each method by varying concentration of gel and reactants, and gel setting time etc. Transparent prismatic bi-pyramidal platy-shaped and spherulite crystals were obtained in various methods. The grown crystals were characterized with the help of FT–IR studies and monoclinic system of crystals were supported with lattice parameters = 9.67628 Å, = 6.7175 Å, = 8.6812 Å, = 113.566°, and = 521.84 Å3 calculated from X-ray diffractogram.

  18. Biomimetic synthesis of calcium-strontium apatite hollow nanospheres

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this work,calcium-strontium apatite (Sr-HA) hollow nanospheres were synthesized by a facile biomimetic method.The structure and property of Sr-HA were characterized by FESEM,TEM,HRTEM,XRD and FT-IR spectroscopy.The influences of different ratios of calcium and strontium on the morphologies of the Sr-HA products were investigated.The experimental results revealed that the hollow spherical Sr-HA,with a size of 30-120 nm in diameter,could be synthesized when the molar ratio of Ca/Sr was 1:1.The possible formation mechanism of the hollow Sr-HA was proposed.The drug release experiments indicated that the hollow spherical Sr-HA had the property of sustained release.

  19. From Here I Walked into Ancient China

    Institute of Scientific and Technical Information of China (English)

    Yan Manman

    2011-01-01

    @@ When I was a little girl, I had heard about the eighth world wonder - terra cotta warriors in Qin Emperor Mausoleum.I have been wishing to visit there to see those magnificent scene which were created thousands of years ago.While with my age added, I gradually learned the terra cotta warriors were lust only one of many ancient marks of Xi'an, which once was capital of 13 dynasties in ancient China.Xi'an actually is a carrier of ancient China culture, where I walked from the modern world to the ancient China.

  20. Strontium isotopic identification of water-rock interaction and ground water mixing.

    Science.gov (United States)

    Frost, Carol D; Toner, Rachel N

    2004-01-01

    87Sr/86Sr ratios of ground waters in the Bighorn and Laramie basins' carbonate and carbonate-cemented aquifer systems, Wyoming, United States, reflect the distinctive strontium isotope signatures of the minerals in their respective aquifers. Well water samples from the Madison Aquifer (Bighorn Basin) have strontium isotopic ratios that match their carbonate host rocks. Casper Aquifer ground waters (Laramie Basin) have strontium isotopic ratios that differ from the bulk host rock; however, stepwise leaching of Casper Sandstone indicates that most of the strontium in Casper Aquifer ground waters is acquired from preferential dissolution of carbonate cement. Strontium isotope data from both Bighorn and Laramie basins, along with dye tracing experiments in the Bighorn Basin and tritium data from the Laramie Basin, suggest that waters in carbonate or carbonate-cemented aquifers acquire their strontium isotope composition very quickly--on the order of decades. Strontium isotopes were also used successfully to verify previously identified mixed Redbeds-Casper ground waters in the Laramie Basin. The strontium isotopic compositions of ground waters near Precambrian outcrops also suggest previously unrecognized mixing between Casper and Precambrian aquifers. These results demonstrate the utility of strontium isotopic ratio data in identifying ground water sources and aquifer interactions.

  1. Response to Comment on "Whole-Genome Shotgun Sequencing of Mitochondria from Ancient Hair Shafts"

    DEFF Research Database (Denmark)

    Gilbert, Marcus Thomas Pius; Miller, Webb; Schuster, Stephan C.

    2008-01-01

    Debruyne et al. challenge the findings of our study and imply that we argue that hair shafts are an overall superior source of ancient DNA than bone. However, the authors are misreading and misinterpreting the conclusions of our study; we claim nothing further than that hair shaft represents...

  2. Genome-wide nucleosome map and cytosine methylation levels of an ancient human genome

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Valen, Eivind; Velazquez, Amhed Missael Vargas;

    2014-01-01

    Epigenetic information is available from contemporary organisms, but is difficult to track back in evolutionary time. Here, we show that genome-wide epigenetic information can be gathered directly from next-generation sequence reads of DNA isolated from ancient remains. Using the genome sequence ...

  3. Ancient Indian Leaps into Mathematics

    CERN Document Server

    Yadav, B S

    2011-01-01

    This book presents contributions of mathematicians covering topics from ancient India, placing them in the broader context of the history of mathematics. Although the translations of some Sanskrit mathematical texts are available in the literature, Indian contributions are rarely presented in major Western historical works. Yet some of the well-known and universally-accepted discoveries from India, including the concept of zero and the decimal representation of numbers, have made lasting contributions to the foundation of modern mathematics. Through a systematic approach, this book examines th

  4. Chinese Ancient Football with Romanticism

    Institute of Scientific and Technical Information of China (English)

    江凌; 李晓勤

    2004-01-01

    Like other traditional Chinese sports, the ancient Chinese football, which used to be called “cuju”, has some differences from several sports in western countries concerning cultural and hamanist purport as well as metal aspiration, although it was similar with modern football to some extent, such as a leather-made ball with a bladder, rectangle sports ground, referee, goal and certain competitiveness. The author tries to talk about such difference in cultural and humanist purport as well as mental aspiration by making a comparison between “cuju” and modern football.

  5. Collision-induced shifts of Rydberg levels of strontium

    Energy Technology Data Exchange (ETDEWEB)

    Marafi, M; Bhatia, K S; Makdisi, Y Y; Philips, G [Department of Physics, Kuwait University, PO Box 5969, Safat, 13060 (Kuwait)

    2003-05-14

    Measurements of spectral line shifts induced by collisions with rare gas perturbers are reported. High Rydberg states were prepared by multiphoton excitation using an excimer pumped tunable dye laser. A thermionic detector inside a heat pipe was used to collect the ionization products resulting from excited states. Analysis of the data for the shifts of the absorption transition to 5snd {sup 1}D{sub 2} states in strontium is presented.

  6. Collision-induced shifts of Rydberg levels of strontium

    Science.gov (United States)

    Marafi, M.; Bhatia, K. S.; Makdisi, Y. Y.; Philips, G.

    2003-05-01

    Measurements of spectral line shifts induced by collisions with rare gas perturbers are reported. High Rydberg states were prepared by multiphoton excitation using an excimer pumped tunable dye laser. A thermionic detector inside a heat pipe was used to collect the ionization products resulting from excited states. Analysis of the data for the shifts of the absorption transition to 5snd 1D 2 states in strontium is presented.

  7. Treatment of metastatic bone pain with strontium-89.

    Science.gov (United States)

    Robinson, R G; Spicer, J A; Preston, D F; Wegst, A V; Martin, N L

    1987-01-01

    We have utilized 89Sr as palliative treatment for bone pain secondary to metastatic cancer in the skeleton of over 200 patients. The best results have been in patients with carcinoma of the prostate (80% response rate) and breast (89%). Results in a small number of patients with a variety of other cell types were not nearly as encouraging. Strontium-89 provides excellent palliation in the management of bone pain secondary to prostate and breast carcinoma.

  8. Complex Impedance Studies of Optically Excited Strontium Barium Niobate

    Science.gov (United States)

    2007-11-02

    has a tetragonal tungsten - bronze structure. The unit cell for this structure, illustrated below in Fig. 2.1, consists of ten oxygen octahedra joined...4 Kittel, pp. 373-374. 5 P. B. Jamieson, et al, “Ferroelectric Tungsten Bronze -Type Crystal Structures. I. Barium Strontium Niobate...Oxford, 1987). 2. C. Kittel, Introduction to Solid State Physics, (Wiley, New York, 1986). 3. P. B. Jamieson, et al, “Ferroelectric Tungsten

  9. Lifetimes of ultra-long-range strontium Rydberg molecules

    CERN Document Server

    Camargo, F; Ding, R; Sadeghpour, H R; Yoshida, S; Burgdörfer, J; Dunning, F B; Killian, T C

    2015-01-01

    The lifetimes of the lower-lying vibrational states of ultralong-range strontium Rydberg molecules comprising one ground-state 5s2 1S0 atom and one Rydberg atom in the 5s38s 3S1 state are reported. The molecules are created in an ultracold gas held in an optical dipole trap and their numbers determined using ?eld ionization, the product electrons being detected by a microchannel plate. The measurements show that, in marked contrast to earlier measurements involving rubidium Rydberg molecules, the lifetimes of the low-lying molecular vibrational states are very similar to those of the parent Rydberg atoms. This results because the strong p-wave resonance in low-energy electronrubidium scattering, which plays an important role in determining the molecular lifetimes, is not present for strontium. The absence of this resonance o?ers advantages for experiments involving strontium Rydberg atoms as impurities in quantum gases and for testing theories of molecular formation and decay.

  10. Production of very-high-n strontium Rydberg atoms

    Science.gov (United States)

    Ye, S.; Zhang, X.; Killian, T. C.; Dunning, F. B.; Hiller, M.; Yoshida, S.; Nagele, S.; Burgdörfer, J.

    2013-10-01

    The production of very-high-n (n˜300-500) strontium Rydberg atoms is explored using a crossed-laser-atom-beam geometry. n1S0 and n1D2 states are created by two-photon excitation via the 5s5p 1P1 intermediate state using radiation with wavelengths of ˜461 and ˜413 nm. Rydberg atom densities as high as ˜3×105 cm-3 have been achieved, sufficient that Rydberg-Rydberg interactions can become important. The isotope shifts in the Rydberg series limits are determined by tuning the 461-nm light to preferentially excite the different strontium isotopes. Photoexcitation in the presence of an applied electric field is examined. The initially quadratic Stark shift of the n1P1 and n1D2 states becomes near-linear at higher fields and the possible use of n1D2 states to create strongly polarized, quasi-one-dimensional electronic states in strontium is discussed. The data are analyzed with the aid of a two-active-electron (TAE) approximation. The two-electron Hamiltonian, within which the Sr2+ core is represented by a semi-empirical potential, is numerically diagonalized allowing the calculation of the energies of high-n Rydberg states and their photoexcitation probabilities.

  11. Production of very-high-$n$ strontium Rydberg atoms

    CERN Document Server

    Ye, Shuzhen; Killian, Thomas C; Dunning, F Barry; Hiller, Moritz; Yoshida, Shuhei; Nagele, Stefan; Burgdörfer, Joachim

    2013-01-01

    The production of very-high-$n$, $n\\sim300$-500, strontium Rydberg atoms is explored using a crossed laser-atom beam geometry. $n$$^{1}$S$_{0}$ and $n$$^{1}$D$_{2}$ states are created by two-photon excitation via the 5s5p $^{1}$P$_{1}$ intermediate state using radiation with wavelengths of $\\sim$~461 and $\\sim$ 413 nm. Rydberg atom densities as high as $\\sim 3 \\times 10^{5}$ cm$^{-3}$ have been achieved, sufficient that Rydberg-Rydberg interactions can become important. The isotope shifts in the Rydberg series limits are determined by tuning the 461 nm light to preferentially excite the different strontium isotopes. Photoexcitation in the presence of an applied electric field is examined. The initially quadratic Stark shift of the $n$$^{1}$P$_{1}$ and $n$$^{1}$D$_{2}$ states becomes near-linear at higher fields and the possible use of $n{}^{1}$D$_{2}$ states to create strongly-polarized, quasi-one-dimensional electronic states in strontium is discussed. The data are analyzed with the aid of a two-active-elect...

  12. Allyl strontium compounds: synthesis, molecular structure and properties.

    Science.gov (United States)

    Jochmann, Phillip; Davin, Julien P; Maslek, Stefanie; Spaniol, Thomas P; Sarazin, Yann; Carpentier, Jean-Francois; Okuda, Jun

    2012-08-14

    The synthesis and attempted isolation of neutral bis(allyl)strontium [Sr(C(3)H(5))(2)] (1) resulted in the isolation of potassium tris(allyl)strontiate K[Sr(C(3)H(5))(3)] (2). In situ generated 1 shows a pronounced Brønsted basicity, inducing polymerisation of THF. Ate complex 2 crystallises as [K(THF)(2){Sr(C(3)H(5))(3)}(THF)](∞) (2·(THF)(3)). The salt-like solid state structure of 2·(THF)(3) comprises a two-dimensional network of (μ(2)-η(3):η(3)-C(3)H(5))(-) bridged potassium and strontium centres. Synthesis of allyl complexes 1 and 2 utilised SrI(2), [Sr(TMDS)(2)] (3) (TMDS = tetramethyldisilazanide), and [Sr(HMDS)(2)] (HMDS = hexamethyldisilazanide) as strontium precursors. The solid state structure of previously reported [Sr(TMDS)(2)] (3) was established by X-ray single crystal analysis as a dissymmetric dimer of [Sr(2)(TMDS)(4)(THF)(3)] (3·(THF)(3)) with multiple Si-HSr agostic interactions. The presence of ether ligands (THF, 18-crown-6) influenced the Si-HSr resonances in the NMR spectra of the amido complex 3.

  13. Microwave-hydrothermal synthesis of barium strontium titanate nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, A.Z., E-mail: alezipo@yahoo.co [Universidade Federal de Itajuba- Unifei - Campus Itabira, Rua Sao Paulo, 377, Bairro, Amazonas, CEP 35900-37, Itabira, MG (Brazil); Universidade Estadual Paulista- Unesp - Faculdade de Engenharia de Guaratingueta, Av. Dr. Ariberto Pereira da Cunha, 333, Bairro Pedregulho, CEP 12516-410 Guaratingueta, SP (Brazil); Moura, F.; Onofre, T.B. [Universidade Federal de Itajuba- Unifei - Campus Itabira, Rua Sao Paulo, 377, Bairro, Amazonas, CEP 35900-37, Itabira, MG (Brazil); Ramirez, M.A.; Varela, J.A.; Longo, E. [Laboratorio Interdisciplinar em Ceramica (LIEC), Departamento de Fisico-Quimica, Instituto de Quimica, UNESP, CEP 14800-900, Araraquara, SP (Brazil)

    2010-10-22

    Research highlights: {yields} Barium strontium titanate nanoparticles were obtained by the Hydrothemal microwave technique (HTMW) {yields} This is a genuine technique to obtain nanoparticles at low temperature and short times {yields} Barium strontium titanate free of carbonates with tetragonal structure was grown at 130 {sup o}C. - Abstract: Hydrothermal-microwave method (HTMW) was used to synthesize crystalline barium strontium titanate (Ba{sub 0.8}Sr{sub 0.2}TiO{sub 3}) nanoparticles (BST) in the temperature range of 100-130 {sup o}C. The crystallization of BST with tetragonal structure was reached at all the synthesis temperatures along with the formation of BaCO{sub 3} as a minor impurity at lower syntheses temperatures. Typical FT-IR spectra for tetragonal (BST) nanoparticles presented well defined bands, indicating a substantial short-range order in the system. TG-DTA analyses confirmed the presence of lattice OH- groups, commonly found in materials obtained by HTMW process. FE/SEM revealed that lower syntheses temperatures led to a morphology that consisted of uniform grains while higher syntheses temperature consisted of big grains isolated and embedded in a matrix of small grains. TEM has shown BST nanoparticles with diameters between 40 and 80 nm. These results show that the HTMW synthesis route is rapid, cost effective, and could serve as an alternative to obtain BST nanoparticles.

  14. Strontium isotope analysis of archaeological fauna at the Erlitou site

    Institute of Scientific and Technical Information of China (English)

    ZHAO ChunYan; YANG Jie; YUAN Jing; LI ZhiPeng; XU Hong; ZHAO HaiTao; CHEN GuoLiang

    2012-01-01

    The Erlitou site is located at Yanshi City,Henan Province.This site is a large settlement site of Erlitou culture,and it is dated to 3800-3500 a BP.Five kinds of domestic animals,i.e.,dogs,pigs,sheep,goats,and cattle were found from the site.In this paper,two problems have emerged in studies involving the estimation of local isotope levels and the distinction of migrants from locals.Tooth enamel samples fron 17 domestic animals individuals were analyzed for strontium isotope ratio (87Sr/86Sr),by the thermal ionization mass spectrometry,including 10 pigs,5 sheep and 2 cattle.The results show that the mean 87Sr/86Sr ratios of 10 pigs enamel samples were 0.712078,Based on the local strontium isotopes ratio range determined by the mean 87Sr/86Sr ratios ±2σrof 10 pig enamel samples (0.712256-.711900),we found that five sheep and one cattle from the Erlitou site fell well outside the local strontium isotopes ratio range and were considered to be non-local.

  15. Foreign Guests in Ancient Greece

    Directory of Open Access Journals (Sweden)

    Zora Žbontar

    2013-12-01

    Full Text Available Xenía was a special relationship between a foreign guest and his host in Ancient Greece. The ritual of hosting a foreigner included an exchange of objects, feasting, and the establishment of friendship between people from different social backgrounds. This relationship implied trust, loyalty, friendship, and mutual aid between the people involved. Goods and services were also exchanged without any form of payment. There were no formal laws governing xenía – it was based entirely on a moral appeal. Mutual appreciation between the host and the guest was established during the ritual, but the host did retain a certain level of superiority over the guest. Xenía was one of the most important institutions in Ancient Greece. It had a lot of features and obligations similar to kinship and marriage. In literary sources the word xénos varies in meaning from “enemy stranger”, “friendly stranger”, “foreigner”, “guest”, “host” to “ritual friend”, and it is often hard to tell which usage is appropriate in a given passage. The paper describes the emphasis on hospitality towards foreigners. It presents an example of a depiction indicating xenía is presented, as well as several objects which were traded during the ritual. The paper also addresses the importance of hospitality in Greek drama in general, especially with examples of violations of the hospitality code.

  16. [Ancient history of Indian pharmacy].

    Science.gov (United States)

    Okuda, Jun; Natsume, Yohko

    2010-01-01

    The study of the ancient history of Indian medicine has recently been revived due to the publication of polyglot translations. However, little is known of ancient Indian pharmacy. Archaeological evidence suggests the Indus people lived a settled life approximately in 2500 B.C. Their cities were enjoying the cleanest and most hygienic daily life with elaborate civic sanitation systems. The whole conception shows a remarkable concern for health. Then, the early Aryans invaded India about 1500 B.C. and the Vedic age started. The Rgveda texts contain the hymns for Soma and those for herbs. The term Ayurveda (i.e., science of life) is found in some old versions of both Ramāyana and Mahābhārata and in the Atharvaveda. Suśruta had the credit of making a breakthrough in the field of surgery. The Ayurveda, a work on internal medicine, gives the following transmission of sages: Brahmā-->Daksa-->Prajāpati-->Aśivinau-->Indra-->Caraka. On the other hand, the Suśruta-samhitā, which deals mainly with surgical medicine, explains it as follows; Indra-->Dhanvantari-->Suśruta Both Caraka and Suśruta were medical doctors as well as pharmacists, so they studied more than 1000 herbs thoroughly. The Ayurveda had been used by his devotees for medical purposes. It eventually spread over Asia with the advanced evolution of Buddhism.

  17. Strontium isoscapes in The Netherlands. Spatial variations in 87Sr/86Sr as a proxy for palaeomobility

    NARCIS (Netherlands)

    Kootker, Lisette M.; van Lanen, Rowin J.; Kars, Henk; Davies, Gareth R.

    2016-01-01

    Strontium isotope analysis has been successfully applied to archaeological questions of residential mobility and animal husbandry for over three decades. To obtain a full understanding of variations in archaeological samples, spatial variations in bioavailable strontium should be accurately mapped o

  18. Letter to the editor: Genetics and the archaeology of ancient Israel.

    Science.gov (United States)

    Brody, Aaron J; King, Roy J

    2013-12-01

    This letter is a call for DNA testing on ancient skeletal materials from the southern Levant to begin a database of genetic information of the inhabitants of this crossroads region. In this region, during the Iron I period traditionally dated to circa 1200-1000 BCE, archaeologists and biblical historians view the earliest presence of a group that called itself Israel. They lived in villages in the varied hill countries of the region, contemporary with urban settlements in the coastal plains, inland valleys, and central hill country attributed to varied indigenous groups collectively called Canaanite. The remnants of Egyptian imperial presence in the region lasted until around 1150 BCE, postdating the arrival of an immigrant group from the Aegean called the Philistines circa 1175 BCE. The period that follows in the southern Levant is marked by the development of territorial states throughout the region, circa 1000-800 BCE. These patrimonial kingdoms, including the United Kingdom of Israel and the divided kingdoms of northern Israel and Judah, coalesced varied peoples under central leadership and newly founded administrative and religious bureaucracies. Ancient DNA testing will give us a further refined understanding of the individuals who peopled the region of the southern Levant throughout its varied archaeological and historic periods and provide scientific data that will support, refute, or nuance our sociohistoric reconstruction of ancient group identities. These social identities may or may not map onto genetic data, but without sampling of ancient DNA we may never know. A database of ancient DNA will also allow for comparisons with modern DNA samples collected throughout the greater region and the Mediterranean littoral, giving a more robust understanding of the long historical trajectories of regional human genetics and the genetics of varied ancestral groups of today's Jewish populations and other cultural groups in the modern Middle East and Mediterranean.

  19. Strontium incorporates at sites critical for bone mineralization in rats with renal failure

    Energy Technology Data Exchange (ETDEWEB)

    Oste, Line; Verberckmoes, Steven C.; Behets, Geert J.; Dams, Geert; Bervoets, An R.; De Broe, Marc E.; D' Haese, Patrick C. [Faculty of Medicine, Antwerp University (Belgium); Van Hoof, Viviane O. [Department of Biochemistry, Antwerp University Hospital (Belgium); Bohic, Sylvain [European Synchrotron Radiation Facility, Grenoble (France); Drakopoulos, Michael [Diamond Light Source, Oxfordshire (United Kingdom)

    2007-01-15

    We previously demonstrated the development of a mineralization defect during strontium administration and its reversibility after withdrawal in rats with chronic renal failure. Recently, strontium ranelate has been introduced as a therapeutic agent for osteoporosis. However, caution has to be taken, as this bone disorder mainly develops in elderly people who may present a moderately decreased renal function. In order to assess the ultra-structural localization of strontium in bone and thereby to get a better insight into the element's systemic effects on bone, synchrotron-based x-ray micro-fluorescence was applied, which showed that after 2 weeks of strontium loading (2 g l{sup -1} in drinking water) in rats with renal failure, concomitant with the development of impaired mineralization, the element was localized mainly at the outer edge of the mineralized bone, while after longer loading periods, a more homogeneous distribution was found. After washout, strontium was found at sites deeper within the trabeculae, while newly deposited low-strontium-containing mineral was found at the outer edges. Synchrotron x-ray micro-diffraction analysis showed that strontium is incorporated in the apatite crystal lattice through exchange with calcium. The results show that strontium is initially incorporated in bone at sites of active bone mineralization, close to the osteoid/mineralization front.Most likely, strontium binds to matrix proteins serving as crystal nucleation points and by hetero-ionic substitution with calcium within the hydroxyapatite crystals, thereby impairing further hydroxyapatite formation. After withdrawal, strontium is released from these sites, by which mineralization is restored and the previously formed strontium-containing hydroxyapatite is buried under a new layer of mineralized bone. (authors)

  20. Attitudes Toward Deviant Sex in Ancient Mesopotamia

    Science.gov (United States)

    Bullough, Vern L.

    1971-01-01

    The article concludes that the whole question of sexual life in ancient Mesopotamia is difficult to reconstruct and fraught with many uncertainties. Nevertheless, it seems certain that the ancient Mesopotamians had fewer prohibitions against sex than our own civilization, and regarded as acceptable many practices which later societies condemned.…

  1. Women--Sex Objects in Ancient Egypt.

    Science.gov (United States)

    Mutimer, Brian T. P.

    Although it has been said that the women in Ancient Egypt enjoyed a reasonable state of social and professional equality with men, this paper presents an alternate theory--that women were second-class citizens whose physical prowess was secondary to their role as sex objects. It appears that men and women in Ancient Egypt often participated in the…

  2. The Idea of Ancient Greek Philosophy

    Institute of Scientific and Technical Information of China (English)

    苏雪

    2016-01-01

    As the source of western philosophy, ancient Greek philosophy had a profound influence on western philosophy. Ancient philosophers were hard to reach a consensus on the existence of all the things in the world. They tried to grasp the profound understanding of the world, which is the clue of the history of philosophy.

  3. Mechanisms in ancient Chinese books with illustrations

    CERN Document Server

    Hsiao, Kuo-Hung

    2014-01-01

    This book presents a unique approach for studying mechanisms and machines with drawings that were depicted unclearly in ancient Chinese books. The historical, cultural and technical backgrounds of the mechanisms are explained, and various mechanisms described and illustrated in ancient books are introduced. By utilizing the idea for the conceptual design of modern mechanisms, all feasible designs of ancient mechanisms with uncertain members and joints that meet the technical standards of the subjects’ time periods are synthesized systematically. Ancient Chinese crossbows (the original crossbow and repeating crossbows), textile mechanisms (silk-reeling mechanism, spinning mechanisms, and looms), and many other artisan's tool mechanisms are used as illustrated examples.  Such an approach provides a logical method for the reconstruction designs of ancient mechanisms with uncertain structures. It also provides an innovative direction for researchers to further identify the original structures of mechanisms...

  4. Structural recognition of ancient Chinese ideographic characters

    Institute of Scientific and Technical Information of China (English)

    Li Ning; Chen Dan

    2014-01-01

    Ancient Chinese characters, typically the ideographic characters on bones and bronze before Shang Dynasty (16th—11th century B.C.), are valuable culture legacy of history. However the recognition of Ancient Chinese characters has been the task of paleography experts for long. With the help of modern computer technique, everyone can expect to be able to recognize the characters and understand the ancient inscriptions. This research is aimed to help people recognize and understand those ancient Chinese characters by combining Chinese paleography theory and computer information processing technology. Based on the analysis of ancient character features, a method for structural character recognition is proposed. The important characteristics of strokes and basic components or radicals used in recognition are introduced in detail. A system was implemented based on above method to show the effectiveness of the method.

  5. Ancient origin and maternal inheritance of blue cuckoo eggs.

    Science.gov (United States)

    Fossøy, Frode; Sorenson, Michael D; Liang, Wei; Ekrem, Torbjørn; Moksnes, Arne; Møller, Anders P; Rutila, Jarkko; Røskaft, Eivin; Takasu, Fugo; Yang, Canchao; Stokke, Bård G

    2016-01-12

    Maternal inheritance via the female-specific W chromosome was long ago proposed as a potential solution to the evolutionary enigma of co-existing host-specific races (or 'gentes') in avian brood parasites. Here we report the first unambiguous evidence for maternal inheritance of egg colouration in the brood-parasitic common cuckoo Cuculus canorus. Females laying blue eggs belong to an ancient (∼2.6 Myr) maternal lineage, as evidenced by both mitochondrial and W-linked DNA, but are indistinguishable at nuclear DNA from other common cuckoos. Hence, cuckoo host races with blue eggs are distinguished only by maternally inherited components of the genome, which maintain host-specific adaptation despite interbreeding among males and females reared by different hosts. A mitochondrial phylogeny suggests that blue eggs originated in Asia and then expanded westwards as female cuckoos laying blue eggs interbred with the existing European population, introducing an adaptive trait that expanded the range of potential hosts.

  6. [Anomalous pregnancies in ancient medicine].

    Science.gov (United States)

    Gazzaniga, Valentina

    2010-01-01

    In ancient Greek medicine female physiology is determined by a particular state of non-steady equilibrium, largely based on pregnancy and lactation, presented as the only balanced and healthy periods in women's life. Nonetheless, pregnancy can be also a pathological moment, in particular referring to specific alterations of its 'normal time' ('seven-months', 'eight-months' and 'ten-months' children). The article analyzes the well-known case of myle, an abnormal pregnancy developing in three and sometimes four years, non resolving in a normal delivery, but often in a dramatic haemorrhagic flux. The author compares Hippocratic and Aristotelic testimonies about myle and abnormal pregnancies with the evidence fournished by the historical-religious recent studies about Hera and her parthenogenetic, monstrous children.

  7. [Being old in ancient Hellas].

    Science.gov (United States)

    van Hooff, A J

    1983-08-01

    There is room for a more balanced view of old age among the ancient Greeks than is furnished by De Beauvoir's la Vieillesse and other more or less one-sided publications. The old body was despised by the Greeks of classical times; especially walking with three legs (tripous) was stressed as a mark of old age. The Hippocratic writings show some interest in the infirmities of elderly people. Specific psychic and intellectual qualities were not attributed to senescence: old age brought out good and bad qualities of a person more sharply than before. The share of old people in the population cannot be established with any certainty, but there was always a group of men in their sixties who had specific tasks in society. Old age was not an autonomous theme in art, it was solely accidental. The position of the elderly was challenged occasionally in democratic Athens, but it was never undermined. Old people were never marginated in classical Greece.

  8. Ancient Acupuncture Literature on Apoplexy

    Institute of Scientific and Technical Information of China (English)

    XU Yi-zeng; BI Zhen; Xiao Yuan-chun

    2003-01-01

    This paper reviews twenty-eight Chinese medicine books with complete prescriptions prior to the Qing Dynasty, and analyzes the characteristics of acupoint selection and needling manipulations from the perspective of apoplectic symptoms. It is concluded that,in ancient times, apoplexy is often treated on the basis of its symptoms and a great number of acupoints are employed; hemiplegia is mainly treated by the acupoints of the Large Intestine Meridian and Gallbladder Meridian,with two key acupoints; coma is mainly treated by first-aid acupoints and qi-supplementing acupoints, with seven key acupoints; wry mouth and convulsion are mainly treated by the local acupoints; as for needling manipulations, moxibustion with moxa cones is principally used, while needling is less used.

  9. Genome-wide nucleosome map and cytosine methylation levels of an ancient human genome

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Valen, Eivind; Velazquez, Amhed Missael Vargas;

    2014-01-01

    data generated from hair shafts of a 4000-yr-old Paleo-Eskimo belonging to the Saqqaq culture, we generate the first ancient nucleosome map coupled with a genome-wide survey of cytosine methylation levels. The validity of both nucleosome map and methylation levels were confirmed by the recovery...... of the expected signals at promoter regions, exon/intron boundaries, and CTCF sites. The top-scoring nucleosome calls revealed distinct DNA positioning biases, attesting to nucleotide-level accuracy. The ancient methylation levels exhibited high conservation over time, clustering closely with modern hair tissues...

  10. Obtaining of Nanostructured Powders of Barium and Strontium Hexaferrite by the Polymer Precursor Method

    Directory of Open Access Journals (Sweden)

    V.G. Kostishyn

    2015-12-01

    Full Text Available Studied the possibility of obtaining by precursors in the polymer nanostructured powders of barium hexaferrite BaFe12O19 and strontium hexaferrite SrFe12O19. The reagents were used as starting barium nitrate, strontium nitrate and ferric nitrate nonahydrate (III, and polyethylene glycol-400 used this technology as a polymer.

  11. On the similarity between the energy characteristics of strontium and europium

    Science.gov (United States)

    Belyaev, V. N.

    2016-11-01

    The spectra of Eu, Sr, Eu+, and Sr+ are used as examples to demonstrate the similarity between the energy characteristics of these elements. It is shown that europium is identical to strontium in the strong and inhomogeneous magnetic field whose source in lanthanides is their empty and compact 4 f n strontium with no magnetic fields.

  12. Strontium localization in bone tissue studied by X-ray absorption spectroscopy.

    Science.gov (United States)

    Frankær, Christian Grundahl; Raffalt, Anders Christer; Stahl, Kenny

    2014-02-01

    Strontium has recently been introduced as a pharmacological agent for the treatment and prevention of osteoporosis. We determined the localization of strontium incorporated into bone matrix from dogs treated with Sr malonate by X-ray absorption spectroscopy. A new approach for analyzing the X-ray absorption spectra resulted in a compositional model and allowed the relative distribution of strontium in the different bone components to be estimated. Approximately 35-45% of the strontium present is incorporated into calcium hydroxyapatite (CaHA) by substitution of some of the calcium ions occupying highly ordered sites, and at least 30% is located at less ordered sites where only the first solvation shell is resolved, suggesting that strontium is surrounded by only oxygen atoms similar to Sr(2+) in solution. Strontium was furthermore shown to be absorbed in collagen in which it obtains a higher structural order than when present in serum but less order than when it is incorporated into CaHA. The total amount of strontium in the samples was determined by inductively coupled plasma mass spectrometry, and the amount of Sr was found to increase with increasing dose levels and treatment periods, whereas the relative distribution of strontium among the different components appears to be independent of treatment period and dose level.

  13. Full-Scale and Bench-Scale Studies on the Removal of Strontium from Water (abstract)

    Science.gov (United States)

    Strontium (Sr) is a natural and commonly occurring alkaline earth metal which has an oxidation state of +2 under normal environmental conditions. Stable strontium is suspended in water and is dissolved after water runs through rocks and soil. It behaves very similar to calcium. G...

  14. Synthesis and characterization of strontium carboxylates at room temperature and at high temperature in autoclave vessels

    DEFF Research Database (Denmark)

    Christgau, Stephan; Ståhl, Kenny; Andersen, Jens Enevold Thaulov

    2006-01-01

    -ray crystallography. Optimum conditions were found at T = 120-1400C, a base-to-acid ratio of 1.2 and 15 min. of reaction-time in an autoclave vessel. Large crystals were readily obtained within a time period of hours. The crystal structures of strontium D-glutamate hexahydrate (I) and strontium di-(hydrogen L...

  15. Marking pike fry otoliths with alizarin complexone and strontium : an evaluation of methods

    DEFF Research Database (Denmark)

    Skov, Christian; Grønkjær, P.; Nielsen, C.

    2001-01-01

    Laboratory experiments demonstrated that both alizarin complexone and strontium are useful in mass marking of pike Esox lucius fry otoliths. Visual detection of alizarin complexone marks was considered more reliable than the quantitative analysis of strontium for differentiating marked and unmarked...

  16. Repumping of ultracold strontium atoms using the ^3P2 - ^3D2 transition

    Science.gov (United States)

    Mickelson, P. G.; Martinez de Escobar, Y. N.; Traverso, A. J.; Killian, T. C.

    2008-05-01

    We discuss recent experiments involving ultracold strontium. Using a commercially-available 3 micron laser, we repump atoms out of the ^3P2 level via the ^3D2 state and gain almost a factor of 10 in the number of atoms in our system. This increase in the signal-to-noise ratio enables improved spectroscopy of strontium in our optical trap.

  17. Study on Performance of Empore~(TM) Strontium Rad Disks-Ⅱ

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    EmporeTM Strontium Rad disks produced by 3M Company contain a strontium-selective crown ether extractant loaded on silica particles that are embedded in an inert PTFE matrix. The disks allow aqueous solutions to pass through in high flow rate. It makes

  18. Synthesis and characterization of strontium and barium guanidinate; Synthese und Charakterisierung von Strontium- und Bariumguanidinat

    Energy Technology Data Exchange (ETDEWEB)

    Missong, Ronja

    2016-07-01

    After investigation of the mono-alkali-metal guanidinates in recent years and the structural properties of the various compounds by means of X-ray and neutron diffraction, the guanidinates of the alkaline earth metals seemed to be well investigated. The synthesis of the mono-alkali-metal guanidinates in liquid ammonia has been further developed for the alkaline earth metal guanidinates. Strontium guanidinate was used for the first time to synthesize a compound with a twofold deprotonated guanidinate anion and to study the structure of this compound by means of spectroscopic analysis and different diffraction methods. The structure model was generated from X-ray powder diffraction data, supplemented by density function theory with the help of hydrogen position and subsequently refined and validated with highly resolved neutron diffraction data. The anion has the predicted C3h symmetry and thus resembles the appearance of a Trinacria. The compound of the barium guanidinate with the desired composition Ba (CN3H4) 2 was also investigated by means of IR spectroscopy and different diffraction methods. Structural proposals were developed from X-ray and flight time neutron diffraction data. However, the results of the refinements of these proposals were not satisfactory. In some structure-chemical aspects, however, the individual structural proposals nevertheless produced a uniform picture. The close relationship between the various structural proposals suggests that a final structure could be in many respects consistent with the various structural proposals. [German] Nachdem die Monoalkaliguanidinate in den letzten Jahren untersucht wurden und die strukturellen Eigenschaften der verschiedenen Verbindungen mittels Roentgen- und Neutronenbeugung aufgeklaert werden konnten, schien es aussichtsreich auch die Guanidinate der Erdalkalimetalle zu untersuchen. Die Synthese der Monoalkaliguanidinate in fluessigem Ammoniak wurde fuer die Erdalkalimetallguanidinate weiter entwickelt

  19. Effects of strontium-induced stress on marine microalgae Platymonas subcordiformis (Chlorophyta: Volvocales)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Strontium-induced stress in growth and chlorophyll contents ofPlatymonas subcordiformis was investigated under laboratory condition. The results showed that strontium exposure had little influences in general on growth and chlorophyll contents of the algae except for very high Sr concentrations.The maximum biosorption capacity of strontium ranged from 69.62 to 269.18 mg Sr2+/gdry weight. The algal biomass exhibited high uptake capacity of strontium. Total superoxide dismutase (SOD) activity and the content of lipid peroxidation products malondialdehyde (MDA) were significantly different in different treatments. SOD activity reached the highest level at 0.09 mmol/L that was about 55.8 % higher than that in the control. The MDA content increased significantly at 0.36 mmol/L, which was 2.15 times higher than that in the control, indicating a state of oxidative stress. With the increase of strontium concentration,the amount of fatty acids decreased.

  20. Strontium iodide gamma ray spectrometers for planetary science (Conference Presentation)

    Science.gov (United States)

    Prettyman, Thomas H.; Rowe, Emmanuel; Butler, Jarrhett; Groza, Michael; Burger, Arnold; Yamashita, Naoyuki; Lambert, James L.; Stassun, Keivan G.; Beck, Patrick R.; Cherepy, Nerine J.; Payne, Stephen A.; Castillo-Rogez, Julie C.; Feldman, Sabrina M.; Raymond, Carol A.

    2016-09-01

    Gamma rays produced passively by cosmic ray interactions and by the decay of radioelements convey information about the elemental makeup of planetary surfaces and atmospheres. Orbital missions mapped the composition of the Moon, Mars, Mercury, Vesta, and now Ceres. Active neutron interrogation will enable and/or enhance in situ measurements (rovers, landers, and sondes). Elemental measurements support planetary science objectives as well as resource utilization and planetary defense initiatives. Strontium iodide, an ultra-bright scintillator with low nonproportionality, offers significantly better energy resolution than most previously flown scintillators, enabling improved accuracy for identification and quantification of key elements. Lanthanum bromide achieves similar resolution; however, radiolanthanum emissions obscure planetary gamma rays from radioelements K, Th, and U. The response of silicon-based optical sensors optimally overlaps the emission spectrum of strontium iodide, enabling the development of compact, low-power sensors required for space applications, including burgeoning microsatellite programs. While crystals of the size needed for planetary measurements (>100 cm3) are on the way, pulse-shape corrections to account for variations in absorption/re-emission of light are needed to achieve maximum resolution. Additional challenges for implementation of large-volume detectors include optimization of light collection using silicon-based sensors and assessment of radiation damage effects and energetic-particle induced backgrounds. Using laboratory experiments, archived planetary data, and modeling, we evaluate the performance of strontium iodide for future missions to small bodies (asteroids and comets) and surfaces of the Moon and Venus. We report progress on instrument design and preliminary assessment of radiation damage effects in comparison to technology with flight heritage.

  1. P-type conductivity in annealed strontium titanate

    Energy Technology Data Exchange (ETDEWEB)

    Poole, Violet M.; Corolewski, Caleb D.; McCluskey, Matthew D., E-mail: mattmcc@wsu.edu [Department of Physics and Astronomy, Washington State University, Pullman, WA 99164-2814 (United States)

    2015-12-15

    Hall-effect measurements indicate p-type conductivity in bulk, single-crystal strontium titanate (SrTiO{sub 3}, or STO) samples that were annealed at 1200°C. Room-temperature mobilities above 100 cm{sup 2}/V s were measured, an order of magnitude higher than those for electrons (5-10 cm{sup 2}/V s). Average hole densities were in the 10{sup 9}-10{sup 10} cm{sup −3} range, consistent with a deep acceptor.

  2. Designing Zeeman slower for strontium atoms - towards optical atomic clock

    CERN Document Server

    Bober, Marcin; Gawlik, Wojciech

    2010-01-01

    We report on design and construction of a Zeeman slower for strontium atoms which will be used in an optical atomic clock experiment. The paper describes briefly required specifications of the device, possible solutions, and concentrates on the chosen design. The magnetic field produced by the built Zeeman slower has been measured and compared with the simulations. The system consisting of an oven and Zeeman slower are designed to produce an atomic beam of 10-12 s-1 flux and final velocity of ~30 m/s.

  3. Spectroscopy of strontium Rydberg states using electromagnetically induced transparency

    OpenAIRE

    Mauger, Sarah; Millen, James; Jones, M. P. A.

    2007-01-01

    We report on the all-optical detection of Rydberg states in a effusive atomic beam of strontium atoms using electromagnetically induced transparency (EIT). Using narrow-linewidth CW lasers we obtain an EIT linewidth of 5 MHz. To illustrate the high spectroscopic resolution offered by this method, we have measured isotope shifts of the 5s18d ^1D_2 and 5s19s ^1S_0 Rydberg states. This technique could be applied to high-resolution, non-destructive measurements of ultra-cold Rydberg gases and pla...

  4. Designing Zeeman slower for strontium atoms - towards optical atomic clock

    OpenAIRE

    Bober, Marcin; Zachorowski, Jerzy; Gawlik, Wojciech

    2010-01-01

    We report on design and construction of a Zeeman slower for strontium atoms which will be used in an optical atomic clock experiment. The paper describes briefly required specifications of the device, possible solutions, and concentrates on the chosen design. The magnetic field produced by the built Zeeman slower has been measured and compared with the simulations. The system consisting of an oven and Zeeman slower are designed to produce an atomic beam of 10-12 s-1 flux and final velocity of...

  5. Strontium modified biocements with zero order release kinetics.

    Science.gov (United States)

    Hamdan Alkhraisat, Mohammad; Moseke, Claus; Blanco, Luis; Barralet, Jake E; Lopez-Carbacos, Enrique; Gbureck, Uwe

    2008-12-01

    Strontium-substituted beta-TCP with the general formula Ca((3-x))Sr(x)(PO(4))(2) (0brushite (CaHPO(4).2H(2)O). Release experiments under dynamic conditions for up to 15 days revealed the release of Sr(2+) ions at dose ranges of 12-30 ppm with zero order release kinetic. Cement cytocompatibility was investigated by culturing human osteoblast cell line hFOB1.19 on cement surfaces whereas Sr-containing cements were as good as Sr-free cements in providing a template for cell growth and function.

  6. Experimental study of strontium sorption on fissure filling material

    Energy Technology Data Exchange (ETDEWEB)

    Eriksen, T.E.; Cui, Daqing [Royal Institute of Technology, Stockholm (Sweden). Dept. of Chemistry

    1994-12-01

    We have carried out a comparative study of sorption and desorption of strontium in groundwater on separated magnetic and size fractions of fissure filling material taken from natural fissures in granitic rock. Complete reversibility of the sorption process was demonstrated by identical Freundlich isotherms, isotopic exchangeability and pH dependence of the distribution coefficients Rd. The sorption was found to be strongly pH dependent in the range 3-11. The pH effect can be accommodated in the sorption model by considering the surface areas and surface charges of the minerals in the fissure filling material. 20 refs, 9 figs, 3 tabs.

  7. Strontium titanate resistance modulation by ferroelectric field effect

    CERN Document Server

    Marré, D; Bellingeri, E; Pallecchi, I; Pellegrino, L; Siri, A S

    2003-01-01

    Among perovskite oxides strontium titanate (STO) SrTiO sub 3 undergoes a metal-insulator transition at very low carrier concentration and exhibits high mobility values at low temperature. We exploited such electrical properties and the structural compatibility of perovskite oxide materials in realizing ferroelectric field effect epitaxial heterostructures. By pulsed laser deposition, we grew patterned field effect devices, consisting of lanthanum doped STO and Pb(Zr,Ti)O sub 3. Such devices showed a resistance modulation up to 20%, consistent with geometrical parameters and carrier concentration of the semiconducting channel.

  8. Ion-pair formation in aqueous strontium chloride and strontium hydroxide solutions under hydrothermal conditions by AC conductivity measurements.

    Science.gov (United States)

    Arcis, H; Zimmerman, G H; Tremaine, P R

    2014-09-01

    Frequency-dependent electrical conductivities of solutions of aqueous strontium hydroxide and strontium chloride have been measured from T = 295 K to T = 625 K at p = 20 MPa, over a very wide range of ionic strength (3 × 10(-5) to 0.2 mol kg(-1)), using a high-precision flow AC conductivity instrument. Experimental values for the concentration-dependent equivalent conductivity, Λ, of the two electrolytes were fitted with the Turq-Blum-Bernard-Kunz ("TBBK") ionic conductivity model, to determine ionic association constants, K(A,m). The TBBK fits yielded statistically significant formation constants for the species SrOH(+) and SrCl(+) at all temperatures, and for Sr(OH)2(0) and SrCl2(0) at temperatures above 446 K. The first and second stepwise association constants for the ion pairs followed the order K(A1)(SrOH(+)) > K(A1)(SrCl(+)) > K(A2)[Sr(OH)2(0)] > K(A2)[SrCl2(0)], consistent with long-range solvent polarization effects associated with the lower static dielectric constant and high compressibility of water at elevated temperatures. The stepwise association constants to form SrCl(+) agree with previously reported values for CaCl(+) to within the combined experimental error at high temperatures and, at temperatures below ∼375 K, the values of log10 KA1 for strontium are lower than those for calcium by up to ∼0.3-0.4 units. The association constants for the species SrOH(+) and Sr(OH)2(0) are the first accurate values to be reported for hydroxide ion pairs with any divalent cation under these conditions.

  9. Historias en código genético: Los aportes de los estudios de ADN antiguo en antropología y sus implicancias éticas Historias em código genético: As contribuições dos estudos de ADN antigo em antropologia e suas implicâncias éticas Stories in Genetic Code: The contribution of ancient DNA studies to anthropology and their ethical implications

    Directory of Open Access Journals (Sweden)

    Cristian M. Crespo

    2010-12-01

    Full Text Available Desde hace varias décadas, la antropología biológica comenzó a utilizar marcadores moleculares en estudios poblacionales. A partir de la década de 1990 se desarrollaron diferentes técnicas en biología molecular que permitieron extraer y tipificar ADN conservado en diferentes restos provenientes de museos y sitios arqueológicos. Los estudios de ADN antiguo relacionados con problemáticas arqueológicas conforman hoy un campo de estudio denominado Arqueogenética. Se presentan en este trabajo algunas de las aplicaciones del ADN antiguo. Se discuten las ventajas y limitaciones de estos estudios y su relación con temas éticos y legales.Faz já varias décadas que à antropologia biológica tem começado a usar marcadores moleculares em estudos de população. Ao começo da década de 1990, se desenvolveram técnicas diferentes em biologia molecular que permitiram obter e tipificar o ADN conservado em restos diferentes vindos de museus e sítios arqueológicos. Os estudos de ADN antigo relacionados a problemáticas arqueológicas são hoje um campo de estudo chamado de Arqueogenética. Se apresentam neste trabalho algumas das aplicações do ADN antigo. Também se discutem as vantagens e limitações desses estudos e a sua relação com assuntos éticos e legais.For several decades, biological anthropology has employed different molecular markers in population research. Since 1990 different techniques in molecular biology have been developed allowing preserved DNA extraction and its typification in different samples from museums and archaeological sites. Ancient DNA studies related to archaeological issues are now included in the field of Archaeogenetics. In this work we present some of ancient DNA applications in archaeology. We also discuss advantages and limitations for this kind of research and its relationship with ethic and legal norms.

  10. Aiding the Interpretation of Ancient Documents

    DEFF Research Database (Denmark)

    Roued-Cunliffe, Henriette

    How can Decision Support System (DSS) software aid the interpretation process involved in the reading of ancient documents? This paper discusses the development of a DSS prototype for the reading of ancient texts. In this context the term ‘ancient documents’ is used to describe mainly Greek...... and Latin texts and the term ‘scholars’ is used to describe readers of these documents (e.g. papyrologists, epigraphers, palaeographers). However, the results from this research can be applicable to many other texts ranging from Nordic runes to 18th Century love letters. In order to develop an appropriate...... tool it is important first to comprehend the interpretation process involved in reading ancient documents. This is not a linear process but rather a recursive process where the scholar moves between different levels of reading, such as ‘understanding the meaning of a character’ or ‘understanding...

  11. AN INTERESTING CASE OF ANCIENT SCHWANNOMA

    Directory of Open Access Journals (Sweden)

    Binu

    2015-01-01

    Full Text Available INTRODUCTION : Schwannoma is a common benign tumour of nerve sheath. Degenerating type of schwannoma is called ancient schwannoma. Ancient schwannomas of scalp are rare and are often misdiagnosed as sebaceous cyst or dermoid cyst. CASE REPORT : We present a thirty two year old male presented with scalp swel ling of eight years duration. X - ray showed no intracranial extension. He underwent excision of the tumour and histopathology was reported as ancient schwannoma. DISCUSSION : Histopathologically , ancient schwannomas charecterised by cellular Antoni type A ar eas and less cellular Antoni type - B areas. 9 th , 7 th , 11 th , 5 th and 4 th cranial nerves are often affected and may be associated with multiple neuro fibramatosis (Von - Recklinghausen’s disease. Impact : Case is presented for its rarity and possible pre - operative misdiagnosis

  12. Ancient Magnetic Reversals: Clues to the Geodynamo.

    Science.gov (United States)

    Hoffman, Kenneth A.

    1988-01-01

    Discusses the question posed by some that the earth's magnetic field may reverse. States that rocks magnetized by ancient fields may offer clues to the underlying reversal mechanism in the earth's core. (TW)

  13. DNA from keratinous tissue

    DEFF Research Database (Denmark)

    Bengtsson, Camilla F.; Olsen, Maja E.; Brandt, Luise Ørsted

    2011-01-01

    Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient...... genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle – although little...... systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear...

  14. DNA from keratinous tissue

    DEFF Research Database (Denmark)

    Bengtsson, Camilla Friis; Olsen, Maia E.; Brandt, Luise Ørsted

    2012-01-01

    Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient...... genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle - although little...... systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear...

  15. Monitoring Biodiversity using Environmental DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis

    was less successful than acoustic detections. However, at one site, long-finned pilot whale – a species rarely sighted in the target area – was detected. Another study examines DNA extracted from leeches to account for biodiversity of terrestrial mammals, on which they have been feeding. The persistence......, a study tests the applicability of non-destructive DNA extraction from old and ancient insect remains. DNA is successfully retrieved, amplified and equenced from dried museum beetle specimens up to 188 years old, ermafrost-preserved macrofossils up to 26.000 years old and directly from 1800-3000 years old......As any species interacts with its environment, most of them will at some point expel DNA to their surroundings. Such DNA can be picked up in environmental samples, isolated and analysed. Within the last decade, this has become a multidisciplinary research field known as Environmental DNA (eDNA...

  16. Physico-chemical studies for strontium sulfate radiation dosimeter

    Directory of Open Access Journals (Sweden)

    M.A.H. Rushdi

    2015-04-01

    Full Text Available Anhydrous strontium sulfate (SrSO4 has shown a promise candidate as a dosimeter for low dose applications producing unique EPR signals with γ-rays which it has a linear response relationship (r2 = 0.999 in the range of 1–100 Gy. The present study extended to evaluate the properties of strontium sulfate dosimeter in intermediate dose range of technology applications. It was observed that the intensity of the EPR signal at g = 2.01081 increases with a 3rd polynomial function in the range of 0.10–15 kGy. In addition, the radical (SO4− provides a stable signal with a good reproducibility (0.107%. Other physics characteristic including the collision of mass stopping power dependence of the system and the effect of atomic number in different energy regions were investigated. The uncertainty budget for high doses has obtained from the measurement with value of 3.57% at 2σ confidence level.

  17. Carbon and Strontium Abundances of Metal-Poor Stars

    CERN Document Server

    Lai, David K; Bolte, Michael; Lucatello, Sara

    2007-01-01

    We present carbon and strontium abundances for 100 metal-poor stars measured from R$\\sim $7000 spectra obtained with the Echellette Spectrograph and Imager at the Keck Observatory. Using spectral synthesis of the G-band region, we have derived carbon abundances for stars ranging from [Fe/H]$=-1.3$ to [Fe/H]$=-3.8$. The formal errors are $\\sim 0.2$ dex in [C/Fe]. The strontium abundance in these stars was measured using spectral synthesis of the resonance line at 4215 {\\AA}. Using these two abundance measurments along with the barium abundances from our previous study of these stars, we show it is possible to identify neutron-capture-rich stars with our spectra. We find, as in other studies, a large scatter in [C/Fe] below [Fe/H]$ = -2$. Of the stars with [Fe/H]$<-2$, 9$\\pm$4% can be classified as carbon-rich metal-poor stars. The Sr and Ba abundances show that three of the carbon-rich stars are neutron-capture-rich, while two have normal Ba and Sr. This fraction of carbon enhanced stars is consistent with ...

  18. Strontium-copper selenite-chlorides: Synthesis and structural investigation

    Science.gov (United States)

    Berdonosov, Peter S.; Olenev, Andrei V.; Dolgikh, Valery A.

    2009-09-01

    Two new complex selenite-chlorides of strontium and copper Sr 2Cu(SeO 3) 2Cl 2 (I) and SrCu 2(SeO 3) 2Cl 2 (II) were obtained and characterized by X-ray diffraction technique, DTA and IR spectroscopy. Both compounds crystallize in the monoclinic system I: Sp. gr. P2 1/ n, a=5.22996(3) Å, b=6.50528(4) Å, c=12.34518(7) Å, β=91.3643(2)°, Z=2; II: Sp. gr. P2 1, a=7.1630(14) Å, b=7.2070(14) Å, c=8.0430(16) Å, β=95.92(3)°, Z=2. Comparison of the crystal structure of (I) with the structures of Sr 2M(SeO 3) 2Cl 2 ( M=Co, Ni) was performed. The substitution of strontium atom in the structure of (I) by Cu 2+ ion with a 3 d9 Jahn-Teller distorted surrounding leads to the lowering of the structure symmetry and to the appearance of the noncentrosymmetric structure of (II). The noncentrosymmetric character of the structure of (II) was confirmed by SHG signal (1.2 units relative to an α-quartz powder sample).

  19. Thermal expansion behaviour of barium and strontium zirconium phosphates

    Indian Academy of Sciences (India)

    P Srikari Tantri; K Geetha; A M Umarji; Sheela K Ramasesha

    2000-12-01

    Ba1.5–SrZr4P5SiO24 compounds with = 0, 0.25, 0.5, 0.75, 1.0, 1.25 and 1.5, belonging to the low thermal expansion NZP family were synthesized by the solid state reaction method. The XRD pattern could be completely indexed with respect to R$\\bar{3}$ space group indicating the ordering of vacancy at the divalent cation octahedral sites. The microstructure and bulk thermal expansion coefficient from room temperature to 800°C of the sintered samples have been studied. All the samples show very low coefficient of thermal expansion (CTE), with = 0 samples showing negative expansion. A small substitution of strontium in the pure barium compound changes the sign of CTE. Similarly, = 1.5 sample (pure strontium) shows a positive CTE and a small substitution of barium changes its sign. = 1.0 and 1.25 samples have almost constant CTE over the entire temperature range. The low thermal expansion of these samples can be attributed to the ordering of the ions in the crystal structure of these materials.

  20. Development of the strontium iodide coded aperture (SICA) instrument

    Science.gov (United States)

    Mitchell, Lee J.; Phlips, Bernard F.; Grove, J. Eric; Cordes, Ryan

    2015-08-01

    The work reports on the development of a Strontium Iodide Coded Aperture (SICA) instrument for use in space-based astrophysics, solar physics, and high-energy atmospheric physics. The Naval Research Laboratory is developing a prototype coded aperture imager that will consist of an 8 x 8 array of SrI2:Eu detectors, each read out by a silicon photomultiplier. The array would be used to demonstrate SrI2:Eu detector performance for space-based missions. Europium-doped strontium iodide (SrI2:Eu) detectors have recently become available, and the material is a strong candidate to replace existing detector technology currently used for space-based gamma-ray astrophysics research. The detectors have a typical energy resolution of 3.2% at 662 keV, a significant improvement over the 6.5% energy resolution of thallium-doped sodium iodide. With a density of 4.59 g/cm and a Zeff of 49, SrI2:Eu has a high efficiency for MeV gamma-ray detection. Coupling this with recent improvements in silicon photomultiplier technology (i.e., no bulky photomultiplier tubes) creates high-density, large-area, low-power detector arrays with good energy resolution. Also, the energy resolution of SrI2:Eu makes it ideal for use as the back plane of a Compton telescope.

  1. Surface topology and electronic structure of layered strontium ruthenates

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, Robert; Klinke, Melanie; Waelsch, Michael; Mietke, Sebastian; Matzdorf, Rene [Experimentalphysik II, Universitaet Kassel (Germany); Peng, Jin; Mao, Zhiqiang [Department of Physics, Tulane University, New Orleans (United States)

    2012-07-01

    In complex materials the interplay of properties like crystal structure, electronic structure and magnetism results in very interesting physical phenomena. The Ruddlesden-Popper series of layered Strontium Ruthenates Sr{sub n+1}Ru{sub n}O{sub 3n+1} describes one class of these materials. The double and triple layer systems behave like a Fermi liquid up to the transition temperature of 15 K and 24 K, respectively. In both compounds the local density of states (LDOS) shows a peak within the dip-like feature around the Fermi energy E{sub F}. Using low-temperature (LT) STM and STS we studied the temperature dependence of the LDOS in the range from 4.7 to 35 K. By increasing the temperature the peak within the dip in the LDOS at E{sub F} is only affected by thermal broadening. The surface unit cell of the Strontium Ruthenates exhibits a c(2 x 2) super structure, which is stable from 4.7 K up to room temperature as shown by our atomically resolved LT STM images and room temperature LEED experiments.

  2. Intrinsic challenges in ancient microbiome reconstruction using 16S rRNA gene amplification.

    Science.gov (United States)

    Ziesemer, Kirsten A; Mann, Allison E; Sankaranarayanan, Krithivasan; Schroeder, Hannes; Ozga, Andrew T; Brandt, Bernd W; Zaura, Egija; Waters-Rist, Andrea; Hoogland, Menno; Salazar-García, Domingo C; Aldenderfer, Mark; Speller, Camilla; Hendy, Jessica; Weston, Darlene A; MacDonald, Sandy J; Thomas, Gavin H; Collins, Matthew J; Lewis, Cecil M; Hofman, Corinne; Warinner, Christina

    2015-11-13

    To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli 341-534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon sequencing. Through comparisons of microbial taxonomic counts from paired amplicon (V3 U341F/534R) and shotgun sequencing datasets, we demonstrate that extensive length polymorphisms in the V3 region are a consistent and major cause of differential amplification leading to taxonomic bias in ancient microbiome reconstructions based on amplicon sequencing. We conclude that systematic amplification bias confounds attempts to accurately reconstruct microbiome taxonomic profiles from 16S rRNA V3 amplicon data generated using universal primers. Because in silico analysis indicates that alternative 16S rRNA hypervariable regions will present similar challenges, we advocate for the use of a shotgun metagenomics approach in ancient microbiome reconstructions.

  3. Three Thousand Years of Continuity in the Maternal Lineages of Ancient Sheep (Ovis aries) in Estonia.

    Science.gov (United States)

    Rannamäe, Eve; Lõugas, Lembi; Speller, Camilla F; Valk, Heiki; Maldre, Liina; Wilczyński, Jarosław; Mikhailov, Aleksandr; Saarma, Urmas

    2016-01-01

    Although sheep (Ovis aries) have been one of the most exploited domestic animals in Estonia since the Late Bronze Age, relatively little is known about their genetic history. Here, we explore temporal changes in Estonian sheep populations and their mitochondrial genetic diversity over the last 3000 years. We target a 558 base pair fragment of the mitochondrial hypervariable region in 115 ancient sheep from 71 sites in Estonia (c. 1200 BC-AD 1900s), 19 ancient samples from Latvia, Russia, Poland and Greece (6800 BC-AD 1700), as well as 44 samples of modern Kihnu native sheep breed. Our analyses revealed: (1) 49 mitochondrial haplotypes, associated with sheep haplogroups A and B; (2) high haplotype diversity in Estonian ancient sheep; (3) continuity in mtDNA haplotypes through time; (4) possible population expansion during the first centuries of the Middle Ages (associated with the establishment of the new power regime related to 13th century crusades); (5) significant difference in genetic diversity between ancient populations and modern native sheep, in agreement with the beginning of large-scale breeding in the 19th century and population decline in local sheep. Overall, our results suggest that in spite of the observed fluctuations in ancient sheep populations, and changes in the natural and historical conditions, the utilisation of local sheep has been constant in the territory of Estonia, displaying matrilineal continuity from the Middle Bronze Age through the Modern Period, and into modern native sheep.

  4. Surgical history of ancient China: Part 2.

    Science.gov (United States)

    Fu, Louis

    2010-03-01

    In this second part of ancient Chinese surgical history, the practice of bone setting in China began around 3000 years ago. Throughout this period, significant progress was made, some highlights of which are cited. These methods, comparable with Western orthopaedic technique, are still being practised today. In conclusion, the possible reasons for the lack of advancement in operative surgery are discussed, within context of the cultural, social and religious background of ancient China.

  5. Strontium isotope geochemistry of soil and playa deposits near Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, B.D.; Mahan, S.A.

    1994-12-31

    The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infilling in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from weathering of silicate detritus. However, calcretes from a fan draining a carbonate terrane have strontium compositions dominated locally by the limestone strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system.

  6. Preparation of strontium hexaferrite magnets from celestite and blue dust by mechanochemical route

    Directory of Open Access Journals (Sweden)

    Tiwary R.K.

    2008-01-01

    Full Text Available In the present investigation celestite (natural ore of strontium and blue dust (iron ore fines have been used for the preparation of strontium hexaferrite powder. The mechanical alloying process has been adopted to prepare strontium hexaferrite powder. The celestite after chemical upradation and physically upgraded blue dust alongwith sodium carbonate was taken for the preparation of strontium hexaferrite in this experiment. The high-energy planetary ball mill with tungsten carbide jar and ball was used to prepare strontium hexaferrite powder. A long time of ball milling for different duration has led to displacement solid-state reaction. At the end of each experiment the product was washed thoroughly and dried. The X-ray diffaction study after annealing shows the development of single-phase strontium hexaferrite after 40 hrs. of milling. The resultant powder was compacted under magnetic field and sintered to prepare the magnet after annealing the ferrite powder. The magnetic properties were measured by Pulse magneto meter. The moderate value of coercivity, remanence and energy product were observed in this sintered magnet. The work illustrates the feasibility to prepare strontium hexaferrite magnetic powders directly from natural ores which can reduce the total cost of production as compared to conventional method.

  7. Urinary strontium and the risk of breast cancer: A case-control study in Guangzhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li-Juan [The School of Public Health, Sun Yat-sen University, 74 Zhongshan 2nd Rd, Guangzhou 510080 (China); Tang, Lu-Ying [The School of Public Health, Sun Yat-sen University, 74 Zhongshan 2nd Rd, Guangzhou 510080 (China); The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630 (China); He, Jian-Rong [The School of Public Health, Sun Yat-sen University, 74 Zhongshan 2nd Rd, Guangzhou 510080 (China); Guangzhou Women and Children' s Medical Center, Guangzhou 510623 (China); Su, Yi; Cen, Yu-Ling; Yu, Dan-Dan [The School of Public Health, Sun Yat-sen University, 74 Zhongshan 2nd Rd, Guangzhou 510080 (China); Wu, Bang-Hua [The Guangdong Prevention and Treatment Center for Occupational Diseases, Guangzhou 510300 (China); Lin, Ying [The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080 (China); Chen, Wei-Qing [The School of Public Health, Sun Yat-sen University, 74 Zhongshan 2nd Rd, Guangzhou 510080 (China); Song, Er-Wei, E-mail: songerwei02@yahoo.com.cn [The Second Affiliated Hospital, Sun Yat-sen University, 107 Yanjiang West, Guangzhou 510120 (China); Ren, Ze-Fang, E-mail: renzef@mail.sysu.edu.cn [The School of Public Health, Sun Yat-sen University, 74 Zhongshan 2nd Rd, Guangzhou 510080 (China)

    2012-01-15

    Strontium has been widely used in industries like electronic and pharmacy. It has a carcinogenic potential, however, and no study has been conducted to evaluate its effects on cancer risk. The aim of this study was to explore the possible association between strontium and breast cancer risk in a case-control study including 240 incident invasive breast cancer patients and 246 age-matched controls. We measured the urinary concentrations of strontium by inductively coupled plasma mass spectrometry, and conducted face-to-face interviews to obtain information on potential breast cancer risk factors. Multivariable analysis was used to estimate the association. Creatinine-adjusted levels [median (25th, 75th) {mu}g/g] of strontium were 155.59 (99.05, 230.70) in the breast cancer patients and 119.62 (81.97, 163.76) in the controls. Women in the highest tertile of strontium showed 124% increased risk of breast cancer, when compared with those in the lowest tertile after adjustment for the potential risk factors [OR (95% CI): 2.24 (1.42-3.81)]. This association was particularly strong for HER2 positive breast cancer [OR (95% CI): 10.92 (3.53-33.77)], and only occurred among premenopausal women. These results suggest a potential role of strontium in the development of breast cancer and urge further studies on the environmental contamination and the physiological and pathological mechanisms of strontium.

  8. Strontium ranelate improved tooth anchorage and reduced root resorption in orthodontic treatment of rats.

    Science.gov (United States)

    Kirschneck, Christian; Wolf, Michael; Reicheneder, Claudia; Wahlmann, Ulrich; Proff, Peter; Roemer, Piero

    2014-12-05

    The anchorage mechanisms currently used in orthodontic treatment have various disadvantages. The objective of this study was to determine the applicability of the osteoporosis medication strontium ranelate in pharmacologically induced orthodontic tooth anchorage. In 48 male Wistar rats, a constant orthodontic force of 0.25 N was reciprocally applied to the upper first molar and the incisors by means of a Sentalloy(®) closed coil spring for two to four weeks. 50% of the animals received strontium ranelate at a daily oral dosage of 900 mg per kilogramme of body weight. Bioavailability was determined by blood analyses. The extent of tooth movement was measured both optometrically and cephalometrically (CBCT). Relative alveolar gene expression of osteoclastic markers and OPG-RANKL was assessed by qRT-PCR and root resorption area and osteoclastic activity were determined in TRAP-stained histologic sections of the alveolar process. Compared to controls, the animals treated with strontium ranelate showed up to 40% less tooth movement after four weeks of orthodontic treatment. Gene expression and histologic analyses showed significantly less osteoclastic activity and a significantly smaller root resorption area. Blood analyses confirmed sufficient bioavailability of strontium ranelate. Because of its pharmacologic effects on bone metabolism, strontium ranelate significantly reduced tooth movement and root resorption in orthodontic treatment of rats. Strontium ranelate may be a viable agent for inducing tooth anchorage and reducing undesired root resorption in orthodontic treatment. Patients under medication of strontium ranelate have to expect prolonged orthodontic treatment times.

  9. Amino acid-assisted synthesis of strontium hydroxyapatite bone cement by a soft solution freezing method

    Indian Academy of Sciences (India)

    D Gopi; S Nithiya; L Kavitha; J M F Ferreira

    2012-12-01

    Among many cations that can substitute for calcium in the structure of hydroxyapatite, strontium provokes an increasing interest because of its beneficial effect on bone formation and prevention of bone resorption. Strontium-incorporated calcium phosphates show potential in biomedical application, particularly the doped strontium may help in new bone formation. We have synthesized strontium hydroxyapatite powders at 2 °C by a soft solution freezing method using glycine as the template. The structural and morphological characterizations were carried out on the as obtained powders using Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy techniques. Strontium was quantitatively incorporated into hydroxyapatite where its substitution for calcium provoked a linear shift of the infrared absorption bands of the hydroxyl and phosphate groups. The strontium substituted bone cement has potential for use in orthopaedic surgeries. The present study shows that the addition of glycine plays an important role in reducing the particle size of strontium hydroxyapatite which could be used for biomedical applications.

  10. Molecular study on human tuberculosis in three geographically distinct and time delineated populations from ancient Egypt.

    Science.gov (United States)

    Zink, A R; Grabner, W; Reischl, U; Wolf, H; Nerlich, A G

    2003-04-01

    We describe the molecular identification of human tuberculosis (TB) from vertebral bone tissue samples from three different populations of ancient Egypt. The specimens were obtained from the predynastic to early dynastic necropolis of Abydos (7 individuals, c. 3500-2650 B.C.), from a Middle Kingdom to Second Intermediate Period tomb of the necropolis of Thebes-West (37. c. 2100-1550 B.C.) and from five further Theban tombs used in the New Kingdom and the Late Period (39, c. 1450-500 B.C.). A total of 18 cases tested positive for the presence of ancient DNA (aDNA) of the M. tuberculosis complex. Out of the 9 cases with typical macromorphological signs of tuberculous spondylitis, 6 were positive for mycobacterial aDNA (66.7%). Of 24 cases with non-specific pathological alterations, 5 provided a positive result (20.8%). In 50 cases of normally appearing vertebral bones 7 tested positive (14.0%). There were only minor differences in the frequencies between the three populations. These data strongly support the notion that tuberculosis was present and prevalent in ancient Egypt since very early periods of this civilization. The unexpectedly high rate of mycobacterial aDNA in normal bone samples is presumably due to a pre- to perimortal systemic spread of the bacteria and indicates a generalized infection by M. tuberculosis.

  11. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC: A Lead and Strontium Isotope Mortuary Analysis.

    Directory of Open Access Journals (Sweden)

    Benjamin Valentine

    Full Text Available Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people's movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC cemetery burials at Harappa (Pakistan and Farmana (India provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape.

  12. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC): A Lead and Strontium Isotope Mortuary Analysis

    Science.gov (United States)

    Valentine, Benjamin; Kamenov, George D.; Kenoyer, Jonathan Mark; Shinde, Vasant; Mushrif-Tripathy, Veena; Otarola-Castillo, Erik; Krigbaum, John

    2015-01-01

    Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people’s movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC) cemetery burials at Harappa (Pakistan) and Farmana (India) provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape. PMID:25923705

  13. Radiocarbon dating of ancient Japanese documents

    Energy Technology Data Exchange (ETDEWEB)

    Oda, H. [Nagoya Univ., Center for Chronological Research, Nagoya, Aichi (Japan)

    2001-06-01

    History is a reconstruction of past human activity, evidence of which is remained in the form of documents or relics. For the reconstruction of historic period, the radiocarbon dating of ancient documents provides important information. Although radiocarbon age is converted into calendar age with the calibration curve, the calibrated radiocarbon age is still different from the historical age when the document was written. The difference is known as 'old wood effect' for wooden cultural property. The discrepancy becomes more serious problem for recent sample which requires more accurate age determination. Using Tandetron accelerator mass spectrometer at Nagoya University, we have measured radiocarbon ages of Japanese ancient documents, sutras and printed books written dates of which are clarified from the paleographic standpoint. The purpose is to clarify the relation between calibrated radiocarbon age and historical age of ancient Japanese document by AMS radiocarbon dating. This paper reports 23 radiocarbon ages of ancient Japanese documents, sutras and printed books. The calibrated radiocarbon ages are in good agreement with the corresponding historical ages. It was shown by radiocarbon dating of the ancient documents that Japanese paper has little gap by 'old wood effect'; accordingly, ancient Japanese paper is a suitable sample for radiocarbon dating of recent historic period. (author)

  14. Thermal Instability and Microstructure of Strontium M-type Hexaferrite Nanoparticles Synthesized by Citrate Approach

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wenyu; ZHANG Qingjie; GUAN Jianguo

    2006-01-01

    The dried gel of SrFe12O19, prepared by citrate approach, was investigated by means of infrared spectroscopy (IR), thermogravimetric analysis(TG), differential scanning calorimetry(DSC), X-ray diffraction(XRD) techniques, energy dispersive spectroscopy(EDS), and transmission electron microscopy(TEM). The thermal instability and the thermal decomposition of low-temperature strontium M-type hexaferrite crystallized at about 600 ℃ were confirmed for the first time by XRD method. The decomposition of the low-temperature strontium M-type hexaferrite took place at about 688.6 ℃ determined by DSC investigation. The low-temperature strontium M-type hexaferrite nanoparticles were decomposed into SrFeO2.5 with an orthorthombic cell and Fe2O3 with a tetragonal cell as well as possibl α-Fe2O3. The agglomerated particles with sizes less than 200 nm obtained at 800 ℃ were plesiomorphous to strontium M-type hexaferrite. The thermally stable strontium M-type hexaferrite nanoparticles with sizes less than 100nm could take place at 900 ℃. Up to 1000 ℃, the phase transformation to form strontium M-type hexaferrite was ended, the calcinations with the sizes more than 1μm were composed of α-Fe2O3 and strontium M-type hexaferrite. The method of distinguishing γ-Fe2O3 with a spinel structure from Fe2O3 with tetragonal cells by using powder XRD method was proposed. Fe2O3 with tetragonal cells to be crystallized before the crystallization of thermally stable strontium M-type hexaferrite was confirmed for the first time. The reason why α-Fe2O3 as an additional phase appears in the calcinations is the cationic vacancy of strontium M-type hexaferrite, SrFe12-x()xO19 (0≤x≤0.5).

  15. Cryptic species in putative ancient asexual darwinulids (Crustacea, Ostracoda.

    Directory of Open Access Journals (Sweden)

    Isa Schön

    Full Text Available BACKGROUND: Fully asexually reproducing taxa lack outcrossing. Hence, the classic Biological Species Concept cannot be applied. METHODOLOGY/PRINCIPAL FINDINGS: We used DNA sequences from the mitochondrial COI gene and the nuclear ITS2 region to check species boundaries according to the evolutionary genetic (EG species concept in five morphospecies in the putative ancient asexual ostracod genera, Penthesilenula and Darwinula, from different continents. We applied two methods for detecting cryptic species, namely the K/θ method and the General Mixed Yule Coalescent model (GMYC. We could confirm the existence of species in all five darwinulid morphospecies and additional cryptic diversity in three morphospecies, namely in Penthesilenula brasiliensis, Darwinula stevensoni and in P. aotearoa. The number of cryptic species within one morphospecies varied between seven (P. brasiliensis, five to six (D. stevensoni and two (P. aotearoa, respectively, depending on the method used. Cryptic species mainly followed continental distributions. We also found evidence for coexistence at the local scale for Brazilian cryptic species of P. brasiliensis and P. aotearoa. Our ITS2 data confirmed that species exist in darwinulids but detected far less EG species, namely two to three cryptic species in P. brasiliensis and no cryptic species at all in the other darwinulid morphospecies. CONCLUSIONS/SIGNIFICANCE: Our results clearly demonstrate that both species and cryptic diversity can be recognized in putative ancient asexual ostracods using the EG species concept, and that COI data are more suitable than ITS2 for this purpose. The discovery of up to eight cryptic species within a single morphospecies will significantly increase estimates of biodiversity in this asexual ostracod group. Which factors, other than long-term geographic isolation, are important for speciation processes in these ancient asexuals remains to be investigated.

  16. Review and evaluation of extractants for strontium removal using magnetically assisted chemical separation

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C.B.; Rogers, R.D. [Northern Illinois Univ., De Kalb, IL (United States). Dept. of Chemistry; Nunez, L.; Ziemer, M.D.; Pleune, T.T.; Vandegrift, G.F. [Argonne National Lab., IL (United States)

    1995-11-01

    A literature review on extractants for strontium removal was initially performed at Northern Illinois University to assess their potential in magnetically assisted chemical separation. A series of potential strontium extractants was systematically evaluated there using radioanalytical methods. Initial experiments were designed to test the uptake of strontium from nitric acid using several samples of magnetic extractant particles that were coated with various crown ether ligands. High partition coefficient (K{sub d}) values for stimulant tank waste were obtained. Further studies demonstrated that the large partitioning was due to uncoated particles.

  17. A compact and efficient strontium oven for laser-cooling experiments

    OpenAIRE

    Schioppo, M.; Poli, N.; M. Prevedelli; Falke, St.; Lisdat, Ch.; Sterr, U.; G. M. Tino

    2012-01-01

    Here we describe a compact and efficient strontium oven well suited for laser-cooling experiments. Novel design solutions allowed us to produce a collimated strontium atomic beam with a flux of 1.0\\times10^13 s^-1 cm^-2 at the oven temperature of 450 {\\deg}C, reached with an electrical power consumption of 36 W. The oven is based on a stainless-steel reservoir, filled with 6 g of metallic strontium, electrically heated in a vacuum environment by a tantalum wire threaded through an alumina mul...

  18. Surface complexation model for strontium sorption to amorphous silica and goethite

    Directory of Open Access Journals (Sweden)

    Criscenti Louise J

    2008-01-01

    Full Text Available Abstract Strontium sorption to amorphous silica and goethite was measured as a function of pH and dissolved strontium and carbonate concentrations at 25°C. Strontium sorption gradually increases from 0 to 100% from pH 6 to 10 for both phases and requires multiple outer-sphere surface complexes to fit the data. All data are modeled using the triple layer model and the site-occupancy standard state; unless stated otherwise all strontium complexes are mononuclear. Strontium sorption to amorphous silica in the presence and absence of dissolved carbonate can be fit with tetradentate Sr2+ and SrOH+ complexes on the β-plane and a monodentate Sr2+complex on the diffuse plane to account for strontium sorption at low ionic strength. Strontium sorption to goethite in the absence of dissolved carbonate can be fit with monodentate and tetradentate SrOH+ complexes and a tetradentate binuclear Sr2+ species on the β-plane. The binuclear complex is needed to account for enhanced sorption at hgh strontium surface loadings. In the presence of dissolved carbonate additional monodentate Sr2+ and SrOH+ carbonate surface complexes on the β-plane are needed to fit strontium sorption to goethite. Modeling strontium sorption as outer-sphere complexes is consistent with quantitative analysis of extended X-ray absorption fine structure (EXAFS on selected sorption samples that show a single first shell of oxygen atoms around strontium indicating hydrated surface complexes at the amorphous silica and goethite surfaces. Strontium surface complexation equilibrium constants determined in this study combined with other alkaline earth surface complexation constants are used to recalibrate a predictive model based on Born solvation and crystal-chemistry theory. The model is accurate to about 0.7 log K units. More studies are needed to determine the dependence of alkaline earth sorption on ionic strength and dissolved carbonate and sulfate concentrations for the development of

  19. Strontium Localization in Bone Tissue Studied by X-Ray Absorption Spectroscopy

    DEFF Research Database (Denmark)

    Frankær, Christian Grundahl; Raffalt, Anders Christer; Ståhl, Kenny

    2014-01-01

    Strontium has recently been introduced as a pharmacological agent for the treatment and prevention of osteoporosis. We determined the localization of strontium incorporated into bone matrix from dogs treated with Sr malonate by X-ray absorption spectroscopy. A new approach for analyzing the X...... structural order than when present in serum but less order than when it is incorporated into CaHA. The total amount of strontium in the samples was determined by inductively coupled plasma mass spectrometry, and the amount of Sr was found to increase with increasing dose levels and treatment periods, whereas...

  20. Characterization of nucleotide misincorporation patterns in the iceman's mitochondrial DNA.

    Directory of Open Access Journals (Sweden)

    Cristina Olivieri

    Full Text Available BACKGROUND: The degradation of DNA represents one of the main issues in the genetic analysis of archeological specimens. In the recent years, a particular kind of post-mortem DNA modification giving rise to nucleotide misincorporation ("miscoding lesions" has been the object of extensive investigations. METHODOLOGY/PRINCIPAL FINDINGS: To improve our knowledge regarding the nature and incidence of ancient DNA nucleotide misincorporations, we have utilized 6,859 (629,975 bp mitochondrial (mt DNA sequences obtained from the 5,350-5,100-years-old, freeze-desiccated human mummy popularly known as the Tyrolean Iceman or Otzi. To generate the sequences, we have applied a mixed PCR/pyrosequencing procedure allowing one to obtain a particularly high sequence coverage. As a control, we have produced further 8,982 (805,155 bp mtDNA sequences from a contemporary specimen using the same system and starting from the same template copy number of the ancient sample. From the analysis of the nucleotide misincorporation rate in ancient, modern, and putative contaminant sequences, we observed that the rate of misincorporation is significantly lower in modern and putative contaminant sequence datasets than in ancient sequences. In contrast, type 2 transitions represent the vast majority (85% of the observed nucleotide misincorporations in ancient sequences. CONCLUSIONS/SIGNIFICANCE: This study provides a further contribution to the knowledge of nucleotide misincorporation patterns in DNA sequences obtained from freeze-preserved archeological specimens. In the Iceman system, ancient sequences can be clearly distinguished from contaminants on the basis of nucleotide misincorporation rates. This observation confirms a previous identification of the ancient mummy sequences made on a purely phylogenetical basis. The present investigation provides further indication that the majority of ancient DNA damage is reflected by type 2 (cytosine

  1. The Kalash genetic isolate: ancient divergence, drift, and selection.

    Science.gov (United States)

    Ayub, Qasim; Mezzavilla, Massimo; Pagani, Luca; Haber, Marc; Mohyuddin, Aisha; Khaliq, Shagufta; Mehdi, Syed Qasim; Tyler-Smith, Chris

    2015-05-01

    The Kalash represent an enigmatic isolated population of Indo-European speakers who have been living for centuries in the Hindu Kush mountain ranges of present-day Pakistan. Previous Y chromosome and mitochondrial DNA markers provided no support for their claimed Greek descent following Alexander III of Macedon's invasion of this region, and analysis of autosomal loci provided evidence of a strong genetic bottleneck. To understand their origins and demography further, we genotyped 23 unrelated Kalash samples on the Illumina HumanOmni2.5M-8 BeadChip and sequenced one male individual at high coverage on an Illumina HiSeq 2000. Comparison with published data from ancient hunter-gatherers and European farmers showed that the Kalash share genetic drift with the Paleolithic Siberian hunter-gatherers and might represent an extremely drifted ancient northern Eurasian population that also contributed to European and Near Eastern ancestry. Since the split from other South Asian populations, the Kalash have maintained a low long-term effective population size (2,319-2,603) and experienced no detectable gene flow from their geographic neighbors in Pakistan or from other extant Eurasian populations. The mean time of divergence between the Kalash and other populations currently residing in this region was estimated to be 11,800 (95% confidence interval = 10,600-12,600) years ago, and thus they represent present-day descendants of some of the earliest migrants into the Indian sub-continent from West Asia.

  2. Livistona palms in Australia: ancient relics or opportunistic immigrants?

    Science.gov (United States)

    Crisp, Michael D; Isagi, Yuji; Kato, Yohei; Cook, Lyn G; Bowman, David M J S

    2010-02-01

    Eighteen of the 34 species of the fan palm genus Livistona (Arecaceae) are restricted to Australia and southern New Guinea, east of Wallace's Line, an ancient biogeographic boundary between the former supercontinents Laurasia and Gondwana. The remaining species extend from SE Asia to Africa, west of Wallace's Line. Competing hypotheses contend that Livistona is (a) ancient, its current distribution a relict of the supercontinents, or (b) a Miocene immigrant from the north into Australia as it drifted towards Asia. We have tested these hypotheses using Bayesian and penalized likelihood molecular dating based on 4Kb of nuclear and chloroplast DNA sequences with multiple fossil calibration points. Ancestral areas and biomes were reconstructed using parsimony and maximum likelihood. We found strong support for the second hypothesis, that a single Livistona ancestor colonized Australia from the north about 10-17Ma. Spread and diversification of the genus within Australia was likely favoured by a transition from the aseasonal wet to monsoonal biome, to which it could have been preadapted by fire-tolerance.

  3. Discovery of a new family of amphibians from northeast India with ancient links to Africa

    OpenAIRE

    2012-01-01

    The limbless, primarily soil-dwelling and tropical caecilian amphibians (Gymnophiona) comprise the least known order of tetrapods. On the basis of unprecedented extensive fieldwork, we report the discovery of a previously overlooked, ancient lineage and radiation of caecilians from threatened habitats in the underexplored states of northeast India. Molecular phylogenetic analyses of mitogenomic and nuclear DNA sequences, and comparative cranial anatomy indicate an unexpected sister-group rela...

  4. Evidence for Ancient Mesoamerican Earthquakes

    Science.gov (United States)

    Kovach, R. L.; Garcia, B.

    2001-12-01

    Evidence for past earthquake damage at Mesoamerican ruins is often overlooked because of the invasive effects of tropical vegetation and is usually not considered as a casual factor when restoration and reconstruction of many archaeological sites are undertaken. Yet the proximity of many ruins to zones of seismic activity would argue otherwise. Clues as to the types of damage which should be soughtwere offered in September 1999 when the M = 7.5 Oaxaca earthquake struck the ruins of Monte Alban, Mexico, where archaeological renovations were underway. More than 20 structures were damaged, 5 of them seriously. Damage features noted were walls out of plumb, fractures in walls, floors, basal platforms and tableros, toppling of columns, and deformation, settling and tumbling of walls. A Modified Mercalli Intensity of VII (ground accelerations 18-34 %b) occurred at the site. Within the diffuse landward extension of the Caribbean plate boundary zone M = 7+ earthquakes occur with repeat times of hundreds of years arguing that many Maya sites were subjected to earthquakes. Damage to re-erected and reinforced stelae, walls, and buildings were witnessed at Quirigua, Guatemala, during an expedition underway when then 1976 M = 7.5 Guatemala earthquake on the Motagua fault struck. Excavations also revealed evidence (domestic pttery vessels and skeleton of a child crushed under fallen walls) of an ancient earthquake occurring about the teim of the demise and abandonment of Quirigua in the late 9th century. Striking evidence for sudden earthquake building collapse at the end of the Mayan Classic Period ~A.D. 889 was found at Benque Viejo (Xunantunich), Belize, located 210 north of Quirigua. It is argued that a M = 7.5 to 7.9 earthquake at the end of the Maya Classic period centered in the vicinity of the Chixoy-Polochic and Motagua fault zones cound have produced the contemporaneous earthquake damage to the above sites. As a consequences this earthquake may have accelerated the

  5. A portable source of lattice-trapped and ultracold strontium (PLUS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design and demonstrate a portable source of lattice-trapped, ultracold strontium (PLUS). The device uses simplified and robust techniques for loading...

  6. Fractal kinetic characteristics for dissolving and leaching processes of strontium residue

    Institute of Scientific and Technical Information of China (English)

    XU Longjun; WANG Xingmin; QU Ge; ZHOU Zhengguo; YUE Fenhua

    2010-01-01

    The pore structural characteristics of strontium residue were studied with the N2 adsorption method (ASAP2010). The kinetic properties concerning dissolving and leaching strontium waste were described by determining the concentrations of Sr2+, Ba2+ and soluble sulphides in solutions. The results showed that the specific surface area and pore volume increased with decreasing granule diameter, and the micropore surface of the residue was fractal. In the dissolving and leaching processes of strontium residue, soluble ion concentrations increased with decreasing granule diameter of the residue, and the reaction dimension was lower than the fractal dimension of pore surface. Sr2+ and soluble sulphide concentrations significantly exceeded the defined standard values, while Ba2+ concentrations did not, either in the dissolving or leaching solutions. In addition, dissolving and leaching reactions selectively occurred on the micropore surface of strontium residue.

  7. Himalayan tectonics, weathering processes, and the strontium isotope record in marine limestones.

    Science.gov (United States)

    Edmond, J M

    1992-12-01

    The time evolution of the isotopic composition of seawater strontium (the ratio of strontium-87 to strontium-86) over the last 500 million years has the form of an asymmetric trough. The values are highest in the Cambrian and Recent (0.7091) and lowest in the Jurassic (0.7067). Superimposed on this trend are a number of smaller oscillations. Consideration of the geochemical cycle of strontium and the dynamics of weathering shows that only Himalayan-style continental collisions can influence the isotope ratio on the scale observed. The contemporary Himalayan orogeny is by far the largest since the late Precambrian Pan-African event that produced the high in the Cambrian.

  8. Barium iodide and strontium iodide crystals andd scintillators implementing the same

    Science.gov (United States)

    Payne, Stephen A; Cherepy, Nerine J; Hull, Giulia E; Drobshoff, Alexander D; Burger, Arnold

    2013-11-12

    In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector according to another embodiment includes a scintillator optic comprising europium-doped strontium iodide providing at least 50,000 photons per MeV. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI.sub.2 and BaI.sub.2, wherein a ratio of SrI.sub.2 to BaI.sub.2 is in a range of between 0:1 A method for manufacturing a crystal suitable for use in a scintillator includes mixing strontium iodide-containing crystals with a source of Eu.sup.2+, heating the mixture above a melting point of the strontium iodide-containing crystals, and cooling the heated mixture near the seed crystal for growing a crystal. Additional materials, systems, and methods are presented.

  9. A new type of microphone using flexoelectric barium strontium titnate

    Science.gov (United States)

    Kwon, Seol ryung; Huang, Wenbin; Zhang, Shujun; Yuan, Fuh-Gwo; Jiang, Xiaoning

    2014-03-01

    A flexoelectric bridge-structured microphone using bulk barium strontium titanate (Ba0.65Sr0.35TiO3 or BST) ceramic was investigated in this study. The flexoelectric microphone was installed in an anechoic box and exposed to the sound pressure emitted from a loud speaker. Charge sensitivity of the flexoelectric microphone was measured and calibrated using a reference microphone. The 1.5 mm×768 μm×50 μm micro-machined bridge-structured flexoelectric microphone has a sensitivity of 0.92 pC/Pa, while its resonance frequency was calculated to be 98.67 kHz. The analytical and experimental results show that the flexoelectric microphone has both high sensitivity and broad bandwidth, indicating that flexoelectric microphones are potential candidates for many applications.

  10. Precision frequency measurement of visible intercombination lines of strontium.

    Science.gov (United States)

    Ferrari, G; Cancio, P; Drullinger, R; Giusfredi, G; Poli, N; Prevedelli, M; Toninelli, C; Tino, G M

    2003-12-12

    We report the direct frequency measurement of the visible 5s(2) 1S0-5s5p 3P1 intercombination line of strontium that is considered a possible candidate for a future optical-frequency standard. The frequency of a cavity-stabilized laser is locked to the saturated fluorescence in a thermal Sr atomic beam and is measured with an optical-frequency comb generator referenced to the SI second through a global positioning system signal. The 88Sr transition is measured to be at 434 829 121 311 (10) kHz. We measure also the 88Sr-86Sr isotope shift to be 163 817.4 (0.2) kHz.

  11. Characterizing high- n quasi-one-dimensional strontium Rydberg atoms

    Science.gov (United States)

    Hiller, Moritz; Yoshida, Shuhei; Burgdörfer, Joachim; Ye, Shuzhen; Zhang, Xinyue; Dunning, F. Barry

    2014-05-01

    The production of high- n, n ~ 300 , quasi-one-dimensional strontium Rydberg atoms by two-photon excitation of selected extreme Stark states in the presence of a weak dc field is examined using a crossed laser-atom beam geometry. The polarization of the product states is probed using three independent techniques which are analyzed with the aid of classical-trajectory Monte Carlo simulations that employ initial ensembles based on quantum calculations using a two-active-electron model. Comparisons between theory and experiment demonstrate that the product states have large dipole moments, ~ 1 . 0 - 1 . 2n2 a . u . and that they can be engineered using pulsed electric fields to create a wide variety of target states. Research supported by the NSF, the Robert A Welch Foundation, and the FWF (Austria).

  12. Rydberg blockade effects at n ˜300 in strontium

    Science.gov (United States)

    Zhang, X.; Dunning, F. B.; Yoshida, S.; Burgdörfer, J.

    2015-11-01

    Rydberg blockade at n ˜300 , is examined using strontium n F13 Rydberg atoms excited in an atomic beam in a small volume defined by two tightly focused crossed laser beams. The observation of blockade for such states is challenging due to their extreme sensitivity to stray fields and the many magnetic sublevels associated with F states which results in a high local density of states. Nonetheless, with a careful choice of laser polarization to selectively excite only a limited number of these sublevels, sizable blockade effects are observed on an ˜0.1 mm length scale extending blockade measurements into the near-macroscopic regime and enabling study of the dynamics of strongly coupled many-body high-n Rydberg systems under carefully controlled conditions.

  13. Blockade involving high- n, n ~ 300 , strontium Rydberg atoms

    Science.gov (United States)

    Yoshida, Shuhei; Burgdörfer, Joachim; Zhang, Xinyue; Dunning, F. Barry

    2016-05-01

    The blockade of high- n strontium n1F3 Rydberg states contained in a hot atomic beam is investigated both theoretically and experimentally. One difficulty in such experiments is that, once created, Rydberg atoms move out of the excitation volume reducing blockade effects. While the effects of such motion are apparent, the data provide strong evidence of blockade, consistent with theoretical predictions. Because of their relatively high angular momentum (L = 3) , a pair of n1F3 Rydberg atoms have many degenerate states whose degeneracy is removed by Rydberg-Rydberg interactions yielding a high density of states near the target energy. To evaluate the effect of blockade not only the energy shifts but also the modification of the oscillator strengths for excitation have to be taken into account. The n-scaling of the interactions and the importance of high-order multipoles will also be discussed. Research supported by the NSF and Robert A. Welch Foundation.

  14. Early African Diaspora in colonial Campeche, Mexico: strontium isotopic evidence.

    Science.gov (United States)

    Price, T Douglas; Tiesler, Vera; Burton, James H

    2006-08-01

    Construction activities around Campeche's central park led to the discovery of an early colonial church and an associated burial ground, in use from the mid-16th century AD to the late 17th century. Remains of some individuals revealed dental mutilations characteristic of West Africa. Analyses of strontium isotopes of dental enamel from these individuals yielded unusually high (87)Sr/(86)Sr ratios, inconsistent with an origin in Mesoamerica, but consistent with an origin in West Africa in terrain underlain by the West Africa Craton, perhaps near the port of Elmina, a principal source of slaves for the New World during the 16th century. These individuals likely represent some of the earliest representatives of the African Diaspora in the Americas.

  15. Spectroscopic studies and Rietveld refinement of strontium-britholites

    Institute of Scientific and Technical Information of China (English)

    Khaled Boughzala; Ezzedine Ben Salem; Fethi Kooli; Pierre Gravereau; Khaled Bouzouita

    2008-01-01

    Strontium-britholites whose chemical formula was Sr10-xLax(PO4)6-x(SiO4)xF2, where x=0, 1, 2, and 4 were prepared by solid state reaction. The structural refinement carried out using the Rietveld method indicated that La3+ ions were located into the two sites with a strong preference for metal (2) sites especially for low contents. A progressive shift of the F- position along the c-axis outside the centre of the triangle formed by metal (2)-atoms was observed with the increase of x. The infrared and Raman spectra exhibited the characteristic vibration modes of PO4 and SiO4 groups confirming the incorporation of this last group into the apatite structure. The 29Si MAS-NMR spectra exhibited one resonance peak confirming the data obtained by X-ray diffraction, indicating that P and Si were located in the same crystallographic site.

  16. Synthesis and characterization of single-crystal strontium hexaboride nanowires.

    Science.gov (United States)

    Jash, Panchatapa; Nicholls, Alan W; Ruoff, Rodney S; Trenary, Michael

    2008-11-01

    Catalyst-assisted growth of single-crystal strontium hexaboride (SrB6) nanowires was achieved by pyrolysis of diborane (B2H6) over SrO powders at 760-800 degrees C and 400 mTorr in a quartz tube furnace. Raman spectra demonstrate that the nanowires are SrB6, and transmission electron microscopy along with selected area diffraction indicate that the nanowires consist of single crystals with a preferred [001] growth direction. Electron energy loss data combined with the TEM images indicate that the nanowires consist of crystalline SrB 6 cores with a thin (1 to 2 nm) amorphous oxide shell. The nanowires have diameters of 10-50 nm and lengths of 1-10 microm.

  17. The humidity sensing properties and mechanism of strontium-hexaferrite

    CERN Document Server

    Zhang, Hui-Feng; Shao, Gang-Qin; Gao, Zhen-Sheng; Liu, Jin-Hua; Girish, H -N

    2016-01-01

    The humidity sensing properties of n-type strontium-hexaferrite semiconductors are investigated at room temperature. The involved materials include hexaferrites of pure Z-type (Sr3Co2Fe24O41) and X-type (Sr2Co2Fe28O46) / W-type (SrCo2Fe16O27) mixture, in which Fe3+ / Fe2+ ions have different lattice sites. The contact and reactions between water and material surface are demonstrated considering the formation of oxide ion vacancy, singly-ionized / fully-ionized oxide ion vacancy, and the chemisorbed / physisorbed / condensed water. An impedance spectra model is proposed considering the material-electrode interface, interior material, grain boundary, absorbed water and Warburg response. The mechanism of electronic coupled with protonic conduction and humidity sensing mechanism are explained.

  18. Imaging the evolution of an ultracold strontium Rydberg gas

    CERN Document Server

    McQuillen, P; Strickler, T; Dunning, F B; Killian, T C

    2012-01-01

    Clouds of ultracold strontium 5s48s 1S0 or 5s47d 1D2 Rydberg atoms are created by two photon excitation of laser cooled 5s2 1S0 atoms. The spontaneous evolution of the cloud of low orbital angular momentum (low-l) Rydberg states towards an ultracold neutral plasma is observed by imaging resonant light scattered from core ions, a technique that provides both spatial and temporal resolution. Evolution is observed to be faster for the S-states, which display isotropic attractive interactions, than for the D-states, which exhibit anisotropic, principally repulsive interactions. Immersion of the atoms in a dilute ultracold neutral plasma speeds up the evolution and allows the number of Rydberg atoms initially created to be determined.

  19. Niobium-doped strontium titanates as SOFC anodes

    DEFF Research Database (Denmark)

    Blennow Tullmar, Peter; Kammer Hansen, Kent; Wallenberg, L. Reine;

    2008-01-01

    been synthesized with a recently developed modified glycine-nitrate process. The synthesized powders have been calcined and sintered in air or in 9% H(2) / N(2) between 800 - 1400 degrees C. After calcination the samples were single phase Nb-doped strontium titanate with grain sizes of less than 100 nm...... in diameter on average. The phase purity, defect structure, and microstructure of the materials have been analyzed with SEM, XRD, and TGA. The electrical conductivity of the Nb-doped titanate decreased with increasing temperature and showed a phonon scattering conduction mechanism with sigma > 120 S...... ability of the Nb-doped titanates to be used as a part of a SOFC anode. However, the catalytic activity of the materials was not sufficient and it needs to be improved if titanate based materials are to be realized as constituents in SOFC anodes....

  20. Ionoluminescence of trivalent rare-earth-doped strontium barium niobate

    Energy Technology Data Exchange (ETDEWEB)

    Calvo del Castillo, H. [Departamento de Geologia y Geoquimica, Universidad Autonoma de Madrid, Modulo C-VI, Campus de Cantoblanco, 28049 Cantoblanco, Madrid (Spain); Universidad Nacional Automoma de Mexico, Instituto de Fisica, 04510 Ciudad Universitaria, Mexico D.F. (Mexico); Ruvalcaba, J.L. [Universidad Nacional Automoma de Mexico, Instituto de Fisica, 04510 Ciudad Universitaria, Mexico D.F. (Mexico); Bettinelli, M.; Speghini, A. [Dipartimento Scientifico e Tecnologico, Universita di Verona and INSTM, UdR Verona, Ca Vignal, Strada Le Grazie 15, I-37134 Verona (Italy); Barboza Flores, M. [Centro de Investigacion en Fisica, Universidad de Sonora, Hermosillo, Sonora (Mexico); Calderon, T. [Departamento de Geologia y Geoquimica, Universidad Autonoma de Madrid, Modulo C-VI, Campus de Cantoblanco, 28049 Cantoblanco, Madrid (Spain)], E-mail: tomas.calderon@uam.es; Jaque, D.; Garcia Sole, J. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, 28049 Cantoblanco, Madrid (Spain)

    2008-05-15

    Ionoluminescence spectra for different rare-earth ion (Pr{sup 3+} and Eu{sup 3+})-activated Sr{sub x}Ba{sub 1-x}Nb{sub 2}O{sub 6} strontium barium niobate crystals (x=0.33 and 0.60) have been induced with a 3 MeV proton beam for a variety of beam current intensities (45, 40 and 20 nA). The proton-beam induced luminescent spectra have shown features associated with the presence of the rare-earth ion and some spectral features mostly related to the host crystal, which appear only for high beam current intensities. We have compared the ionoluminescence results to those obtained under UV light excitation (photoluminescence technique) where a direct excitation of the band gap would occur.

  1. Strontium in 19th century Australian children's teeth

    Science.gov (United States)

    Williams, A.-M. M.; Donlon, D. A.; Bennett, C. M.; Siegele, R.

    2002-05-01

    The enamel of teeth from 57 children, who died in the mid to late 1800s, were analysed to investigate strontium (Sr) concentrations in historic teeth. Teeth were analysed using proton induced X-ray emission at the Australian Nuclear Science and Technology Organisation (ANSTO). Where available, multiple teeth were analysed for each individual including permanent (molars and premolars) and deciduous teeth (molars). Preliminary results show that Sr does not appear to be affected by the postmortem environment. Sr levels in permanent molars strongly correlate with levels in the premolars but not with the deciduous molars. Concerns are raised over the large variation seen in Sr levels and the effect it would have on the interpretation of Sr levels in studies with small sample sizes.

  2. Trade study for the disposition of cesium and strontium capsules

    Energy Technology Data Exchange (ETDEWEB)

    Claghorn, R.D.

    1996-03-01

    This trade study analyzes alternatives for the eventual disposal of cesium and strontium capsules currently stored at the Waste Encapsulation and Storage Facility as by-product. However, for purposes of this study, it is assumed that at some time in the future, the capsules will be declared high-level waste and therefore will require disposal at an offsite geologic repository. The study considered numerous alternatives and selected three for detailed analysis: (1) overpack and storage at high-level waste canister storage building, (2) overpack at the high-level waste vitrification facility followed by storage at a high-level waste canister storage building, and (3) blend capsule contents with other high-level waste feed streams and vitrify at the high-level waste vitrification facility.

  3. Strontium ranelate is a drug to treat osteoarthrosis

    Directory of Open Access Journals (Sweden)

    Oksana Anatolyevna Nikitinskaya

    2013-01-01

    Full Text Available To prevent disease progression in patients with osteoarthosis (OA remains a challenging problem. Despite the proposed drug, non-drug, and surgical treatments for OA, there is a clinical need for medications that have a structure-modifying effect and are able to delay or prevent cartilage degradation and to alleviate the clinical manifestations of the disease. A 3-year international randomized clinical trial has demonstrated strong evidence for the symptomand structure-modifying effect of strontium ranelate in female and male patients with clinical primary knee OA. The clinical use of the drug opens up new prospects for preventing the progression of the disease in patients with knee and hip OA.

  4. Calcium, Strontium and Barium Homogeneous Catalysts for Fine Chemicals Synthesis.

    Science.gov (United States)

    Sarazin, Yann; Carpentier, Jean-François

    2016-12-01

    The large alkaline earths (Ae), calcium, strontium and barium, have in the past 15 years yielded a brand new generation of heteroleptic molecular catalysts for the production of fine chemicals. However, the integrity of these complexes is often plagued by ligand redistribution equilibria in solution. This personal account retraces the paths followed in our research group towards the design of stable heteroleptic alkalino-earth complexes, including the use of intramolecular noncovalent Ae···H-Si and Ae···F-C interactions. Their implementation as homogenous precatalysts for reactions such as the intramolecular and intermolecular hydroamination and hydrophosphination of activated alkenes, the hydrophosphonylation of ketones, and the dehydrogenative coupling of amines and hydrosilanes that enable the efficient and controlled formations of CP, CN, or SiN σ-bonds, is presented in a synthetic perspective that highlights their overall outstanding catalytic performance.

  5. A novel solvothermal route for obtaining strontium titanate nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Marquez-Herrera, A., E-mail: alfredo.marquez@uaslp.mx [Universidad Autonoma de San Luis Potosi, Departamento de Ingenieria Mecanica Administrativa, Coordinacion Academica Region Altiplano (COARA) (Mexico); Ovando-Medina, Victor M.; Corona-Rivera, Miguel A. [Universidad Autonoma de San Luis Potosi, Departamento de Ingenieria Quimica, Coordinacion Academica Region Altiplano (COARA) (Mexico); Hernandez-Rodriguez, E.; Zapata-Torres, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria IPN (Mexico); Campos-Gonzalez, E.; Guillen-Cervantes, A.; Zelaya-Angel, O.; Melendez-Lira, M. [CINVESTAV-IPN, Departamento de Fisica (Mexico)

    2013-04-15

    Strontium titanate (SrTiO{sub 3}) has attracted a lot of attention because of its possible applications in new microelectronic devices. It is a material with a high dielectric constant, low leakage current, and some of its properties can be changed by adding or modifying the concentration of a dopant, which can be used for a wide range of functional purposes, from simple capacitors to complicated microwave devices. Therefore, in this work, we report the development of a new route to synthesize SrTiO{sub 3} nanoparticles based on the solvothermal method by employing two precursor solutions: strontium chloride and titanium(IV) butoxide. Our route allows the production of cubic SrTiO{sub 3} nanoparticles with a narrow size distribution. The particle sizes range between 8 and 24 nm, forming agglomerates of SrTiO{sub 3} in the range of 128-229 nm. It was demonstrated that the Ti/Sr molar ratio employed into the precursor solution has an important effect onto the chemical composition of the resulting SrTiO{sub 3} nanoparticles: when using Ti/Sr < 1, the formation and incorporation of the SrCO{sub 3} compound into the nanoparticles was observed while with Ti/Sr {>=} 1 nanoparticles are free of contaminants. The as-prepared nanoparticles were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, high-resolution TEM, selected area electron diffraction, scanning electron microscopy, and dynamic light scattering.

  6. Clinoptilolite as an in-situ permeable barrier to strontium migration in ground water

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, K.J.; Martin, P.F.; Szecsody, J.E. [Pacific Northwest Lab., Richland, WA (United States)

    1994-12-31

    Batch adsorption experiments were conducted with three zeolites (clinoptilolite, chabazite, and A-51) to determine their potential applicability as in-situ permeable barriers to ground water strontium migration in the 100-N Area of the Hanford Site. Each of the zeolites was an effective adsorbent for strontium, even in competition with calcium at concentrations typical of Hanford ground water, and the authors determined that clinoptilolite would be the most cost-effective. The strontium adsorption data for calcium-saturated clinoptilolite were fitted to a Langmuir isotherm, which is linear at solution concentrations of less than 10{sup {minus}5} mol/L. In this region, the adsorption coefficient (K{sub d}) was 956 L/kg. Because strontium concentrations in hanford ground water are typically 3 x 10{sup {minus}6} mol/L, assuming linear adsorption (K{sub d} = 956 L/kg) for modeling purposes is appropriate. These data were used to design an effective barrier and were incorporated into a transport model to assess its performance. Calculations indicated that a barrier 1.3 m thick would prevent strontium-90 migration to the Columbia river at 100-N Area for over 50 yr. Because of radioactive decay and adsorption, the maximum breakthrough of strontium-90, approximately 5% of the initial input, would occur at 100 yr. Preliminary experimental work was conducted to determine the adsorption kinetics of strontium on clinoptilolite. A comparison of the adsorption rate of strontium with its residence time (within the barrier) indicates that adsorption kinetics are sufficiently fast that the barrier performance will not be significantly affected.

  7. Preparation and characterization of a novel injectable strontium-containing calcium phosphate cement with collagen

    OpenAIRE

    2015-01-01

    Purpose: To develop a novel injectable strontium-containing calcium phosphate cement with collagen. Methods: A novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenⅠ, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated. Results: The results showed that the material could be injected with an excellen...

  8. Similarity and Difference of Phase Transition FCC – BCC in Calcium and Strontium

    Directory of Open Access Journals (Sweden)

    V.V. Pozhivatenko

    2016-11-01

    Full Text Available Features of polymorphism in calcium and strontium from the point of view of similarity of physical processes which occur at change of pressure and temperatures are researched. The known experimental facts are added calculated (first principal and fit by results which illustrate both similarity, and difference of structural phase transitions FCC – BCC in calcium and strontium. The increase in similarity of the effects connected with polymorphism is shown, at increase both pressure, and temperatures.

  9. Pulsed electrodeposition for the synthesis of strontium-substituted calcium phosphate coatings with improved dissolution properties

    Energy Technology Data Exchange (ETDEWEB)

    Drevet, Richard, E-mail: richard.drevet@univ-reims.fr; Benhayoune, Hicham

    2013-10-15

    Strontium-substituted calcium phosphate coatings are synthesized by pulsed electrodeposition on titanium alloy (Ti6Al4V) substrates. Experimental conditions of the process are optimized in order to obtain a coating with a 5% atomic substitution of calcium by strontium which corresponds to the best observations on the osteoblast cells activity and on the osteoclast cells proliferation. The physical and chemical characterizations of the obtained coating are carried out by scanning electron microscopy associated to energy dispersive X-ray spectroscopy (EDXS) for X-ray microanalysis and the structural characterization of the coating is carried out by X-ray diffraction. The in vitro dissolution/precipitation properties of the coated substrates are investigated by immersion into Dulbecco's Modified Eagle Medium (DMEM) from 1 h to 14 days. The calcium, phosphorus and strontium concentrations variations in the biological liquid are assessed by Induced Coupled Plasma - Atomic Emission Spectroscopy for each immersion time. The results show that under specific experimental conditions, the electrodeposition process is suitable to synthesize strontium-substituted calcium phosphate coatings. Moreover, the addition of hydrogen peroxide (H{sub 2}O{sub 2}) into the electrolytic solution used in the process allows us to observe a control of the strontium release during the immersion of the prosthetic materials into DMEM. - Highlights: • Strontium-substituted calcium phosphate coatings are successfully electrodeposited. • The strontium is homogeneously distributed in the synthesized prosthetic coating. • This divalent cation modifies the calcium phosphate structure. • H{sub 2}O{sub 2} addition in the electrolyte allows to control the coating's stoichiometry. • This implies a control of the strontium release in the physiological environment.

  10. Neodymium and strontium isotope evidence for crustal contamination of continental volcanics.

    Science.gov (United States)

    Carter, S R; Evensen, N M; Hamilton, P J; O'nions, R K

    1978-11-17

    Combined neodymium and strontium isotope studies on Tertiary volcanics from northwest Scotland indicate that their parental mantle isotopic compositions have been substantially modified in many instances by contamination with the Precambrian continental crust through which they were erupted. The occurrence of samarium-neodymium and rubidium-strontium "pseudoisochrons" of different ages in these contaminated continental volcanics indicates that they are artifacts of the contamination processes and have no temporal significance with respect to mantle fractionation events.

  11. Sorption of strontium on uranyl peroxide: implications for a high-level nuclear waste repository.

    Science.gov (United States)

    Sureda, Rosa; Martínez-Lladó, Xavier; Rovira, Miquel; de Pablo, Joan; Casas, Ignasi; Giménez, Javier

    2010-09-15

    Strontium-90 is considered the most important radioactive isotope in the environment and one of the most frequently occurring radionuclides in groundwaters at nuclear facilities. The uranyl peroxide studtite (UO2O2 . 4H2O) has been observed to be formed in spent nuclear fuel leaching experiments and seems to have a relatively high sorption capacity for some radionuclides. In this work, the sorption of strontium onto studtite is studied as a function of time, strontium concentration in solution and pH. The main results obtained are (a) sorption is relatively fast although slower than for cesium; (b) strontium seems to be sorbed via a monolayer coverage of the studtite surface, (c) sorption has a strong dependence on ionic strength, is negligible at acidic pH, and increases at neutral to alkaline pH (almost 100% of the strontium in solution is sorbed above pH 10). These results point to uranium secondary solid phase formation on the spent nuclear fuel as an important mechanism for strontium retention in a high-level nuclear waste repository (HLNW).

  12. Physicochemical Properties and Cellular Responses of Strontium-Doped Gypsum Biomaterials

    Directory of Open Access Journals (Sweden)

    Amir Pouria

    2012-01-01

    Full Text Available This paper describes some physical, structural, and biological properties of gypsum bioceramics doped with various amounts of strontium ions (0.19–2.23 wt% and compares these properties with those of a pure gypsum as control. Strontium-doped gypsum (gypsum:Sr was obtained by mixing calcium sulfate hemihydrate powder and solutions of strontium nitrate followed by washing the specimens with distilled water to remove residual salts. Gypsum was the only phase found in the composition of both pure and gypsum:Sr, meanwhile a shift into lower diffraction angles was observed in the X-ray diffraction patterns of doped specimens. Microstructure of all gypsum specimens consisted of many rod-like small crystals entangled to each other with more elongation and higher thickness in the case of gypsum:Sr. The Sr-doped sample exhibited higher compressive strength and lower solubility than pure gypsum. A continuous release of strontium ions was observed from the gypsum:Sr during soaking it in simulated body fluid for 14 days. Compared to pure gypsum, the osteoblasts cultured on strontium-doped samples showed better proliferation rate and higher alkaline phosphatase activity, depending on Sr concentration. These observations can predict better in vivo behavior of strontium-doped gypsum compared to pure one.

  13. Classification of ancient mammal individuals using dental pulp MALDI-TOF MS peptide profiling.

    Directory of Open Access Journals (Sweden)

    Thi-Nguyen-Ny Tran

    Full Text Available BACKGROUND: The classification of ancient animal corpses at the species level remains a challenging task for forensic scientists and anthropologists. Severe damage and mixed, tiny pieces originating from several skeletons may render morphological classification virtually impossible. Standard approaches are based on sequencing mitochondrial and nuclear targets. METHODOLOGY/PRINCIPAL FINDINGS: We present a method that can accurately classify mammalian species using dental pulp and mass spectrometry peptide profiling. Our work was organized into three successive steps. First, after extracting proteins from the dental pulp collected from 37 modern individuals representing 13 mammalian species, trypsin-digested peptides were used for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis. The resulting peptide profiles accurately classified every individual at the species level in agreement with parallel cytochrome b gene sequencing gold standard. Second, using a 279-modern spectrum database, we blindly classified 33 of 37 teeth collected in 37 modern individuals (89.1%. Third, we classified 10 of 18 teeth (56% collected in 15 ancient individuals representing five mammal species including human, from five burial sites dating back 8,500 years. Further comparison with an upgraded database comprising ancient specimen profiles yielded 100% classification in ancient teeth. Peptide sequencing yield 4 and 16 different non-keratin proteins including collagen (alpha-1 type I and alpha-2 type I in human ancient and modern dental pulp, respectively. CONCLUSIONS/SIGNIFICANCE: Mass spectrometry peptide profiling of the dental pulp is a new approach that can be added to the arsenal of species classification tools for forensics and anthropology as a complementary method to DNA sequencing. The dental pulp is a new source for collagen and other proteins for the species classification of modern and ancient mammal individuals.

  14. Twins in Ancient Greece: a synopsis.

    Science.gov (United States)

    Malamitsi-Puchner, Ariadne

    2016-01-01

    This brief outline associates twins with several aspects of life in Ancient Greece. In Greek mythology twins caused ambivalent reactions and were believed to have ambivalent feelings for each other. Very often, they were viewed as the representatives of the dualistic nature of the universe. Heteropaternal superfecundation, which dominates in ancient myths, explains on one hand, the god-like qualities and, on the other hand, the mortal nature of many twins. An assumption is presented that legends referring to twins might reflect the territorial expansions of Ancient Greeks in Northern Mediterranean, around the Black Sea, in Asia Minor, as well as North East Africa. In conclusion, in Greek antiquity, twins have been used as transitional figures between myth and reality.

  15. Genetic diversity among ancient Nordic populations

    DEFF Research Database (Denmark)

    Melchior, Linea Cecilie; Lynnerup, Niels; Siegismund, Hans Redlef

    2010-01-01

    the ancient Danes (average 13%) than among extant Danes and Scandinavians ( approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic...... samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least...... for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture....

  16. The Vindolanda Tablets and the Ancient Economy

    DEFF Research Database (Denmark)

    Evers, Kasper Grønlund

    , a model is outlined which takes into account the different economic behaviours revealed by the tablets and attempts to fit them together into one coherent, economic system, whilst also relating the activities to questions of scale in the ancient economy; moreover, the conclusions drawn in the study......, the aim is to investigate how best to comprehend the economic system attested at Vindolanda and to consider the wider implications for studies of the ancient economy in general. This is accomplished by a three-step approach: first, the nature of the Vindolandan evidence is assessed, and the state...... of research on both studies of the ancient economy and the economy of early Roman Britain is accounted for, so as to highlight the value of the Vindolanda Tablets and lay the ground for the interpretations which follow. Secondly, the economic activities attested by the tablets are analysed in terms of market...

  17. Palaeoparasitology - Human Parasites in Ancient Material.

    Science.gov (United States)

    Araújo, Adauto; Reinhard, Karl; Ferreira, Luiz Fernando

    2015-01-01

    Parasite finds in ancient material launched a new field of science: palaeoparasitology. Ever since the pioneering studies, parasites were identified in archaeological and palaeontological remains, some preserved for millions of years by fossilization. However, the palaeoparasitological record consists mainly of parasites found specifically in human archaeological material, preserved in ancient occupation sites, from prehistory until closer to 2015. The results include some helminth intestinal parasites still commonly found in 2015, such as Ascaris lumbricoides, Trichuris trichiura and hookworms, besides others such as Amoebidae and Giardia intestinalis, as well as viruses, bacteria, fungi and arthropods. These parasites as a whole provide important data on health, diet, climate and living conditions among ancient populations. This chapter describes the principal findings and their importance for knowledge on the origin and dispersal of infectious diseases.

  18. Synthesis and Characterization of Hot-Roll and Cold-Roll Byproduct-Derived Strontium Hard Ferrites

    Directory of Open Access Journals (Sweden)

    H. S. Woon

    2009-01-01

    Full Text Available Problem statement: Ceramic permanent magnets or more commonly known as strontium hexagonal ferrites have been widely used in permanent magnetic materials as they provide high remanence, high coercivity, relatively high energy product and good chemical stability. In this study, we treated factory byproduct from hot-roll and cold-roll steel industry was used as raw material in synthesis of strontium hexagonal hard ferrites. Approach: X-Ray Diffraction (XRD was employed to confirm the formation of strontium hard ferrite compound. Vibrating Sample Magnetometer (VSM was used to analyze the magnetic properties of samples prepared. Results: The magnetic properties, namely remanence and coercivity of factory byproduct-derived strontium hard ferrites were compared. The cold-roll-derived strontium hard ferrite showed higher remanence in this study. Conclusion: This implied that cold-roll byproduct was a better candidate to replace hematite in preparation of strontium hard ferrites compared to hot-roll byproduct.

  19. Effect of strontium nitride on the properties of Sr2SisNs:Eu2+ red phosphor

    Institute of Scientific and Technical Information of China (English)

    Teng Xiaoming; Liang Chao; He Jinhua

    2011-01-01

    The nitride phosphor Sr2SisNs :Eu2+ was synthesized by the high temperature solid-state method. The properties of Sr2 Si5Ns:Eu2+ were discussed by X-ray diffraction (XRD) scanning electron microscope (SEM) and spectra analysis. The XRD pattern shows that the single phase produces when strontium nitride is a bit excessive.The SEM photo implies that the excessive strontium nitride works as a flux in the reaction system. The position of emission peak is also located at about 612 nm as strontium nitride is excessive. The luminescent intensity of the phosphor adding excessive strontium nitride is higher than that of the phosphor introducing stoichiometric strontium nitride. The optimized content of nitride strontium was 2.05 mol/mol for the obtained phosphor with excellent properties.

  20. 废碳酸锶制备八水氢氧化锶联产硝酸钠研究%STUDY ON PREPARATION OF STRONTIUM HYDROXIDE AND SODIUM NITRATE FROM WASTE STRONTIUM CARBONATE.

    Institute of Scientific and Technical Information of China (English)

    郭志余

    2001-01-01

    The process for preparation of strontium hydroxide and sodium nitrate from waste strontium, which comes from industrial strontium carbonate production, is introduced. It provides a new way for utilizing waste strontium carbonate.%介绍了利用工业SCO3生产过程中产生的废次碳酸锶生产八水氢氧化锶及硝酸钠的工艺,为废锶的综合利用提出了一条新的途径。