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Paleoantropologia: approccio tradizionale e nuove metodologie. Alcuni casi studio su reperti di età preistorica e storica.
Full text linkRIASSUNTO
La presente ricerca è incentrata sullo studio di resti umani preistorici, protostorici e storici, affrontato attraverso l’utilizzo di metodologie classiche e moderne. Il fine di tale ricerca è stato quello di cercare di combinare in modo efficace le procedure tradizionali di indagine con quelle di tipo moderno in base alle diverse problematiche scientifiche presentate per ogni caso studio. A conclusione di questo lavoro è possibile affermare che alla base delle scelte metodologiche in paleoantropologia ci sono una serie di variabili di cui si deve tener conto. La maggior parte degli studi moderni viene ad oggi eseguita soprattutto sui reperti preistorici, per due motivi fondamentali, il primo riguarda la scarsità di tali reperti e quindi la necessità di mettere in atto indagini sempre più approfondite e specifiche al fine di recuperare il numero maggiore di informazioni possibili, il secondo è legato proprio al tipo di informazioni che si vogliono recuperare. Infatti, attraverso i reperti umani preistorici, è possibile indagare non solo l’aspetto prettamente legato alle modalità di vita degli individui all’interno di una popolazione e tra popolazioni diverse, ma anche quelle che riguardano i passaggi evolutivi legati alla nostra specie e i caratteri fisici fenotipici e genotipici che distinguono l’uomo moderno dalle specie di Homo che l’hanno preceduto. Ad esempio è utile analizzare lo spessore dello smalto dentale delle varie specie perché esso è caratterizzante a livello tassonomico e fornisce informazioni sui cambiamenti evolutivi a carico dell’apparato masticatorio. Ma è inutile applicare tale studio alle popolazioni umane storiche perché non ci sono differenze statisticamente rilevanti di spessore dello smalto in individui che appartengono tutti alla stessa specie e quindi, il tipo di informazione che si andrebbe ad ottenere non contribuirebbe in alcun modo alla conoscenza di tali popolazioni. Le domande alle quali lo studio di un reperto può rispondere sono determinanti nella scelta dei tipi di analisi da effettuare. C’è però da sottolineare che spesso anche i costi e i tempi che i laboratori impongono agli operatori influiscono su tali scelte, infatti, ad esempio, creare banche dati di immagini virtuali 3DCT di reperti umani non solo preistorici ma anche storici sarebbe importante almeno per la documentazione dei reperti stessi, i quali possono subire danneggiamenti dovuti alle manipolazioni dei paleoantropologi che li devono analizzare. Nel presente studio sono state anche affrontate le problematiche legate ai resti umani che fanno parte di collezioni storiche, come ad esempio l’Uomo del Chiostraccio, il cui scheletro, scoperto negli anni ’60, è rimasto a giacere nei magazzini dell’Università di Siena per ben 50 anni prima di essere “riscoperto” e studiato con nuove metodologie. Tali problematiche sono dovute principalmente ai vari trattamenti eseguiti con sostanze sintetiche e/o naturali subiti dai reperti ed effettuati in maniera indiscriminata da parte degli operatori in un epoca in cui non vi erano direttive precise per la conservazione dei materiali, trattamenti ai quali oggi è difficile, se non impossibile, risalire ma che influenzano gli esiti delle analisi chimico-fisiche e molecolari odierne. Per questo le datazioni al radiocarbonio hanno avuto esiti discordanti (12.000 anni BP e 2000 anni BP) e solo l’analisi dell’ aDNA (DNA antico) ha potuto, in parte, discriminare l’antichità del reperto posizionandolo in un arco temporale che non può essere antecedente ai 2000 anni BP. E’ stato quindi necessario effettuare analisi antropometriche e statistiche che hanno permesso di confrontare la morfologia del cranio dell’Uomo del Chiostraccio con quella di individui Romani, Etruschi e Paleolitici per cercare di inquadrare il reperto in modo più preciso.ABSTRACT
This thesis focuses on the study of pre-protohistoric and historic human remains through the use of both classic and cutting-edge methodologies. The aim of the research is to effectively combine the traditional investigation procedures with the modern ones, taking into account different scientific questions characterizing every case-study. To date cutting-edge methodologies are mostly applied on prehistoric finds. This is due to two main reasons: 1) the scarcity of prehistoric remains entails the use of deeper and deeper specific analyses in order to retrieve as much information as possible; 2) the type of information sought for. Prehistoric human remains can provide data not only about life-ways of individuals within a population and among different populations, but also about the evolution of our species and the physical phenotypic and genotypic features by which Modern Humans differ from the other Homo species who went extinct. For instance it is useful to analyze thickness of dental enamel of different species as this feature is taxonomically discriminating and provides information on the evolutionary changes of the masticatory system. Conversely it is of no use to perform this analysis on historic human populations because there are no statistically relevant differences in the enamel thickness amongst individuals belonging to the same species. Obviously, in this case, the information which may be obtained would not contribute to the knowledge of such populations. The questions which the study of a particular find can answer are crucial for the choice of the analyses to be performed. However laboratory time and costs may influence such choices. In this sense creating data-sets of 3DCT virtual images of both prehistoric and historic human remains would be important . This allows to record human remains in detail and to avoid the loss of data in case of damage to the original pieces. In this thesis issues relating to human remains belonging to old collections have also been taken into consideration. Illustrative of this issue is the story of the Chiostraccio Man, whose skeleton was discovered in the 1960s and was stored at the University of Siena for 50 years before being “rediscovered” and studied with new methodologies. Problems are mainly connected to the synthetic and/or natural substances that were used to treat these remains. These problems can also represent a bias for radiometric measurements and for DNA analyses. In this case traditional methodologies can be usefully employed to put the remains at issue in the right chronological framework from the anthropological standpoint
Genome diversity of domesticated Acinetobacter baumannii ATCC 19606T strains
Full text link: Acinetobacter baumannii has emerged as an important opportunistic pathogen worldwide, being responsible for large outbreaks for nosocomial infections, primarily in intensive care units. A. baumannii ATCC 19606T is the species type strain, and a reference organism in many laboratories due to its low virulence, amenability to genetic manipulation and extensive antibiotic susceptibility. We wondered if frequent propagation of A. baumannii ATCC 19606T in different laboratories may have driven micro- and macro-evolutionary events that could determine inter-laboratory differences of genome-based data. By combining Illumina MiSeq, MinION and Sanger technologies, we generated a high-quality whole-genome sequence of A. baumannii ATCC 19606T, then performed a comparative genome analysis between A. baumannii ATCC 19606T strains from several research laboratories and a reference collection. Differences between publicly available ATCC 19606T genome sequences were observed, including SNPs, macro- and micro-deletions, and the uneven presence of a 52 kb prophage belonging to genus Vieuvirus. Two plasmids, pMAC and p1ATCC19606, were invariably detected in all tested strains. The presence of a putative replicase, a replication origin containing four 22-mer direct repeats, and a toxin-antitoxin system implicated in plasmid stability were predicted by in silico analysis of p1ATCC19606, and experimentally confirmed. This work refines the sequence, structure and functional annotation of the A. baumannii ATCC 19606T genome, and highlights some remarkable differences between domesticated strains, likely resulting from genetic drift
Pianosa-Birth of an Island Nineteen million years of geological history, from the first rocks to the deer migration in the last glacial period
No full textThe oldest deposits of the island are Miocene in age and outcrop along most of the western cliff and at Cala della Ruta. The Miocene includes two formations: Marina del Marchese Formation and Golfo della Botte Formation. The first, of Burdigalian age, is characterized by ~150 m outcropping thickness of marl-prevalent succession; the second, of upper Tortonian - Messinian age, is composed of ~300 m thickness of clayey-sandy deposits, which are conglomeratic in the upper part. Between the two Miocene formations there is a wide stratigraphic gap spanning the late Burdigalian - early Tortonian interval. During this period, the tectonic uplift of the area prevented new sedimentary series formation. The deposition restarted with Golfo della Botte Formation unconformably resting on Marina del Marchese one; today, the two formations show the same bed setting but different strike: 15°-20° the first and 5°-10° the second. The Pianosa Formation rests unconformably on both Miocene ones and it shows a sub-horizontal setting. The unconformity between the Pianosa Formation and the depositions of Golfo della Botte Formation, of late Tortonian - early Messinian age, shows that a second uplift occurred between the two sedimentary phases, probably induced by the emplacement of Elba and Montecristo's granitic plutons,. This uplift determined surfacing and tilting of Upper Miocene deposits and consequently further deformation of Lower Miocene one. Pianosa Formation is composed by a dozen metres of biocalcarenites, poor of inorganic components but rich of fossils (mainly molluscs, algae, bryozoans, echinoids and in minority crustaceans and fishes) which evidence a shallow marine environment. Along mostly of the western cliff and at Cala dell'Alga on the eastern coast, protruding on the morphological profile, there is a reddish-brown, well-lithified, rich of fluoroapatite, oxide and iron carbonate level, which divides in two units the sedimentary succession of the Pianosa Formation. Sediments below this level (lower unit) present sub-horizontal setting and are Piacenzian in age, whereas the upper one (upper unit) show clinostratification and is Early Pleistocene in age. The two units of Pianosa Formation are paraconformably related and the oxidation-fosfatization of the lower unit top evidences that between the two sedimentary episodes a period of emergence occurred. Above the Pianosa Formation unconformable rest shell deposits, relating to the early Late Pleistocene (“Tyrrhenian age”) sea rise. These consist of a few metres thick- succession rich in fossils, informally well known as “Panchina”, and sporadically outcropping along the eastern and southern low-line coast of the island. Finally, deposits of continental environment close the Pianosa Succession. They are characterized by sandy clays and red sandstones, which are related to aeolian and colluvial accumulations or breccias of collapsed caves and holes. The island surface typically consist of vast well-developed red soils, sometimes the older ones filled caves, which include many terrestrial vertebrate fossils, date back to Late Pleistocene-Holocene. The presence of these fossils is undoubtedly related to the phases connecting the island with the mainland
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
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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