1,721,042 research outputs found
Persistence of spermatozoa on decomposing human skin : a scanning electron microscopy study
No full textFinding spermatozoa is of the utmost importance in judicial cases involving both the living and the dead; however, most of literature actually deals with inner genitalia and does not take into consideration the chance of external deposition of semen on skin, which is not rare. In addition, the most advanced microscopic technologies such as scanning electron microscopy (SEM) have not been thoroughly investigated within this specific field of research. This study aims at applying SEM analysis to samples of decomposed skin in order to test its potential in detecting spermatozoa particularly in decomposed cadavers. A sample of skin was obtained at autopsy and divided into two thin strips; one of the samples was used as a negative control. Semen was then taken from a "donor" (with a normal spermiogram) and was spread onto the other skin sample. Every 3 days for the first 15 days (for a total of six samples), a standard slide was prepared from swabs on the treated and control skin and analyzed by standard light microscopy. In addition, every 7 days up to 91 days (3 months circa), a skin sample was taken from the positive and negative control and examined by SEM for a total of 14 samples. Results show that after 12 days, light microscopy failed in detecting spermatozoa, whereas they were still visible up to 84 days by SEM analysis. This study therefore suggests the persistence of sperm structures in time and in decomposing material as well as the possible application of SEM technology to decomposed skin in order to detect semen
Detection of metal residues on bone using SEM-EDS. Part 2. : sharp force injury
No full textScanning electron microscopy coupled with X-ray energy dispersive spectrometry (SEM-EDS) is extensively seen in the literature for the improvement of the macroscopic analysis of sharp lesions, but very few indications concerning its real potential in the forensic context, particularly in forensic anthropology, are at the moment available. This paper represents a pilot study for the analysis of the behaviour of metallic residues found on bone after sharp force injury. Fourteen lesions were made on human bone (radius), cleaned of all soft tissues, with seven different sharp tools (three metal instruments, three metal saws and a baked-clay knife). Tools and lesions underwent SEM-EDS. From 3 to 18 particles were detected on each lesion, whose diameter was included between 0.5 and 150 μm. In 58% of cases, particle composition was concordant with the instrument used. The results seem to suggest that sharp force injury frequently leaves relatively few residues on bone, particularly in the case of common types of metal. Saws showed slightly more contamination with other residues than knives, which may be explained by the capability of the saw's teeth to retain the residues of previously encountered material. In addition, metal residues related to the tool used to cut the bone were located on the edges/walls of lesions in the case of saw marks, whereas they were more frequently found on the kerf floor in the case of knives/scissors, with the exception of the baked clay knife which when it leaves residues at all, seemed to leave them equally divided between the floor, the edges and the surrounding bone
Il "mistero" della Stazione
No full textIntroduzione e Scopo
In ambito di patologia forense la scheda inter-gruppi sul sopralluogo, approvata dalla SIMLA, mostra come il lavoro multidisciplinare sia anche alla base della diagnosi differenziale in tema di lesività, come illustrato dal caso qui descritto.
Materiali e Metodi
All’alba di una mattina di maggio, un ragazzo veniva rinvenuto sui binari di una stazione ferroviaria, in stato di incoscienza, con vaste lacerazioni del cuoio capelluto, plurime escoriazioni e svariate fratture cervicali. Fino a 2 ore prima del rinvenimento il ragazzo era in una vicina discoteca ma non ricordava nulla di quanto accaduto. Qual era l’origine di tale lesività?
Risultati e Discussione
La lesività al cranio mostrava un’intaccatura del tavolato osseo sottostante le lacerazioni del cuoio capelluto, ed agli arti inferiori vi erano plurime lesioni escoriative di cui alcune “a stampo”, particolarmente suggestive. Nel sospetto di un possibile investimento ferroviario, vennero eseguiti plurimi sopralluoghi sui treni con campionamenti genetici e merceologici. Fu inoltre effettuata un’analisi accurata dei vestiti. Ciò che si è potuto escludere è stato l’intervento di una lesività esogena diversa rispetto a quella da impatto tra corpo e treno, poiché nessun alternativo meccanismo di produzione delle lesioni era prospettabile.
Conclusione
Il caso qui discusso avrebbe sicuramente beneficiato dell’utilizzo della scheda inter-gruppi per facilitare il lavoro multidisciplinare. La risposta al quesito sulla modalità lesiva comportò in più lo studio del percorso di due treni trovatisi a passare nella sede di rinvenimento nell’unica finestra temporale possibile. Ma quale dei due treni fu responsabile dell’investimento? Ed è possibile che un treno riesca a passare sopra ad un corpo in posizione supina senza colpirlo
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
SEM-EDX analysis of microscopic surface debris collected from the skin - preliminary study
No full textLooking for evidence on cadavers goes beyond what is visible; invisible traces can be sampled on the victim’s body but this happens rarely with environmental ones. Given the lack of related literature on this subject, the present study was devised to verify to what extent sampling on skin for SEM-EDX analysis can convey interesting data. In the first research stage, stubs were taken from the skin of six living subjects and their work environments. In the second stage, twenty-four well preserved cadavers recovered from known environments were sampled. The study has demonstrated the presence of ubiquitous chemical elements, constituting a kind of ‘background noise’. However, some characteristic elements have been identified: calcium and spores for the flower shop and the florist, calcium for the bakery and the baker, zinc for the foundry and the workman, and iron for the mechanic’s workshop and the mechanic, thus demonstrating some potential that justifies future studies. Our results have demonstrated how environmental traces may be detected on ‘clean’ skin, a useful tool to connect body and environment. Even if this research represents just a first pilot study, results seem promising toward the recognition of the potential evidential value of this ‘invisible’ part of cadavers
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
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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