1,720,973 research outputs found
Rekonstruktion mikrobieller Evolution durch Sequenzierung alter DNA
No full textThe study of human pathogens, their genomes and their evolution has been revolutionized by the introduction of ancient DNA techniques both in the lab and in silico. Today, palaeogenomic research can reconstruct microbial genomes starting from as much as a couple of reads detected during screenings. With every year, the number of organisms and genomes increases, and with it the field’s power to answer a wide range of questions pertaining to the evolution and the dynamics of studied pathogens
Metagenomic analysis of dental calculus in ancient Egyptian baboons
Get PDFDental calculus, or mineralized plaque, represents a record of ancient biomolecules and food residues. Recently, ancient metagenomics made it possible to unlock the wealth of microbial and dietary information of dental calculus to reconstruct oral microbiomes and lifestyle of humans from the past. Although most studies have so far focused on ancient humans, dental calculus is known to form in a wide range of animals, potentially informing on how human-animal interactions changed the animals' oral ecology. Here, we characterise the oral microbiome of six ancient Egyptian baboons held in captivity during the late Pharaonic era (9th-6th centuries BC) and of two historical baboons from a zoo via shotgun metagenomics. We demonstrate that these captive baboons possessed a distinctive oral microbiome when compared to ancient and modern humans, Neanderthals and a wild chimpanzee. These results may reflect the omnivorous dietary behaviour of baboons, even though health, food provisioning and other factors associated with human management, may have changed the baboons' oral microbiome. We anticipate our study to be a starting point for more extensive studies on ancient animal oral microbiomes to examine the extent to which domestication and human management in the past affected the diet, health and lifestyle of target animals.sponsorship: We acknowledge the Musee des Confluences (Lyon, France), especially Didier Berthet for his ongoing support and permission to sample the archaeological material. This research was carried out within the framework of the "Baboons Project" supported by the Ministere de la Culture et de la Communication (France); the Royal Belgian Institute of Natural Sciences in Brussels (Belgium) and the Agence Nationale de la Recherche from the "Investissement d'Avenir" program ANR-11-LABX-0032-01 LabEx ARCHIMEDE (Montpellier, France). We wish to thank Thomas Haverkamp for discussion of preliminary data, and Elena Marinova for her help in the interpretation of the dietary analysis. ATO was funded by the Center for Evolution and Medicine Postdoctoral Fellowship at Arizona State University. We would also like to thank the Academy of Natural Sciences of Drexel University (formerly of Philadelphia) for providing samples and in particular we would like to thank Ned Gilmore and Ted Daeschler for their assistance in sample collection. Bioinformatic analyses were performed on the Abel Cluster, owned by the University of Oslo and the Norwegian metacenter for High Performance Computing (NOTUR) and operated by the Department for Research Computing at the University Center for Information Technology Services (USIT), University of Oslo. CO was funded by Satsningsmiljo Grant Comparative Infection Biology (COMPI), Department of Biosciences, University of Oslo and the European Research Council (ERC) Starting Grant Project HIDDEN FOODS (G. A. 639286), Department of Oral and Maxillofacial Sciences, Spienza University of Rome. MG and OK were funded by the European Research Council (ERC) under the FP7IDEAS-ERC Program (Grant 324249). (Ministere de la Culture et de la Communication (France), Royal Belgian Institute of Natural Sciences in Brussels (Belgium), Agence Nationale de la Recherche from the "Investissement d'Avenir" program LabEx ARCHIMEDE (Montpellier, France)|ANR-11-LABX-0032-01, Center for Evolution and Medicine Postdoctoral Fellowship at Arizona State University, Satsningsmiljo Grant Comparative Infection Biology (COMPI), Department of Biosciences, University of Oslo, European Research Council (ERC) Starting Grant Project HIDDEN FOODS|G. A. 639286, Department of Oral and Maxillofacial Sciences, Spienza University of Rome, European Research Council (ERC) under the FP7IDEAS-ERC Program|324249)status: Publishe
Genomic blueprint of a relapsing fever pathogen in 15th century Scandinavia
Get PDFLouse-borne relapsing fever (LBRF) is known to have killed millions of people over the course of European history and remains a major cause of mortality in parts of the world. Its pathogen, Borrelia recurrentis, shares a common vector with global killers such as typhus and plague and is known for its involvement in devastating historical epidemics such as the Irish potato famine. Here, we describe a European and historical genome of B. recurrentis, recovered from a 15th century skeleton from Oslo. Our distinct European lineage has a discrete genomic makeup, displaying an ancestral oppA1 gene and gene loss in antigenic variation sites. Our results illustrate the potential of ancient DNA research to elucidate dynamics of reductive evolution in a specialized human pathogen and to uncover aspects of human health usually invisible to the archaeological record.publishedVersio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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