1,720,984 research outputs found
Cancer patient mtDNA forensic identification: a case report
No full textMitochondrial genome mutations are described in many kinds of human malignancies, including lung cancer. These mutations can be base substitutions, insertion or deletions, and the 1.1 kb d-loop region has been recently identified as a mutational "hot spot" in the mitochondrial DNA (mtDNA) of neoplastic tissue. Cancer cells harbour homoplasmic rather than heteroplasmic mutations; therefore, somatic mutant mtDNA appears as a single copy among a majority of wild-type mtDNA molecules and becomes dominant in the cancer cell probably due to the growth/survival advantages that such mutation confers to the cell.
The authors will present a case of forensic identification in which a widow claimed for medical malpractice the physicians that had taken care of her husband, who was affected by a malignant lung disease, as she thought that he had been wrongly diagnosed with cancer and therefore he had undergone massive and inappropriate therapies that finally led him to death.
Therefore the Prosecutor ordered the seizure of the neoplastic histological samples attributed to the deceased and the comparison of the genetic profile obtained from these samples with those of the relatives, in order to establish the presence or absence of genetic compatibility among the neoplastic tissue and the relatives of the deceased.
To this end, autosomal markers were analyzed and compared with those of the two daughters of the deceased, while Y-chromosome markers and mtDNA were analyzed and compared with those of his brother.
While both autosomal and Y-chromosome markers confirmed the correspondence of the histological samples to the deceased, in the case of mtDNA a difference at nucleotide 16093 of HVRI region has been highlighted: in fact the brother had a C while the lung tissue examined showed a transition from C to T. In order to ascertain the full genetic compatibility it was therefore necessary to study the nature of this nucleotide difference by cloning of PCR products.
Sequencing of PCR cloning products thus allowed to highlight an heteroplasmic site (tending to homoplasmy) at nt.16093 in tumor cells with respectively 75% of mutated mtDNA and only 25% of germ-line mtDNA compatible with the brother reference sequence.
After attending this presentation, attendees will understand how to manage a forensic identification case in a cancer patient, when only neoplastic tissue is available for the genetic analyses.
This presentation will impact the forensic community by demonstrating that, because frequency of mutations in mtDNA is higher than in nuclear DNA in a variety of human cancers (as suggested from several studies), the mtDNA profiling should not be applied as the unique analysis in cases of forensic identification of cancer patients when only neoplastic tissue is available. Moreover, direct automated sequencing lacks adequate resolution to detect mtDNA heteroplasmy when, as in cancer cells, the somatic mutation tend to homoplasmy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Origin and gender determination of dried blood on a statue of the Virgin Mary
No full textIn Italy, blood exudation from objects of worship recurs frequently in ancient chronicles and literature, in popular beliefs, and even in morn mass- media reports. This phenomenon, that was associated with epochal or catastrophic events, has roots that reach classical antiquity. In the last few years, several events connected with the detection of bloody 'tears' on statues of the Virgin Mary required forensic medicine investigations. In the present report we describe genetic investigations conducted on dried blood of unknown derivation found on a statuette representing the Virgin Mary. To test the human or animal origin of the blood, we amplified Alu-specific sequences from DNAs obtained from the unknown sample and from humans, large apes, various Old and New World monkeys, a prosimian, mouse common domestic artiodactyls and chicken. This investigation restricted the range of possible origin of the statue blood to humans, apes and Old World monkeys. To test the male or female origin of the blood, we used a multiplex nested polymerase chain reaction method, that allows the simultaneous amplification of the X- specific locus DXZ4 and of the Y-specific locus SRY. Considering the unlikelihood of an origin from simian Old World primates, the exclusive amplification of the X-specific product from the unknown sample and from human female blood controls, compared to the amplification of distinct X- Y- specific bands from human male blood controls, strongly supports a human female origin of the statue blood
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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