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Stato delle conoscenze palinologiche
No full textLa paleopalinologia ha una lunga tradizione nel Lazio, fin dall’inizio degli anni Sessanta
Old and new methods in geometric morphometrics applied to the study of human evolution: case studies
Get PDFThe main aim of this thesis is the application of Geometric Morphometric methods on different case-studies for the study of human evolution. When combined with techniques of acquisition of 3D models, Geometric Morphometrics allows us: - to investigate different experimental designs;
- to analyse the interaction of several aspects on morphological adaptations detected within taxon-specific studies (e.g., allometry, phylogenetic signal, functional factors);
- to study fragmentary fossils and incomplete specimens, through estimation of missing data and 3D virtual restoration (e.g., surface and curve slid semilandmark);
- to plan, code and test new algorithms and/or methodological approaches.
The first part deals with the use of smoothing filters applied to 3D model for Geometric Morphometric studies. These algorithms are used to remove the background noise deriving from digital acquisition (e.g., photogrammetry, laser scan and computerized tomography scan). The effects of the different smoothing filters have been assessed. In particular have been defined guidelines for a correct use of these algorithms, besides the developing of an automatized tool, in R environment, to find the best combination between algorithm type, settings and number of iterations.
The second part consists of a protocol developed, with the collaboration of the University of Freiburg, for the digital retrodeformation of fossil specimens showing evidence of shearing, bending and compressing alterations due to taphonomic processes. Traditional methods of retrodeformation only use a sparse set of bilateral landmarks; the number of points appears to affects the success of retrodeformation. On the contrary, this method uses, in addition to the landmark configurations, the curve and surface semilandmarks, which allow us to capture
morphological information more accurately. This protocol was applied here to the neanderthalian cranium of Saccopastore 1.
The third part reports the results of the first analysis on the specimen nicknamed "Pàus” (St.n.166623), recently discovered near Spinadesco in the Po Valley (Northern Italy). A set of 100 semilandmarks was built on the specimen and slid, using a set of 6 landmark, on a comparative sample including specimens dated to the Middle-to-Late Pleistocene. The results show how the morphology of “Pàus” is consistent with the variability observed in the Neanderthal lineage.
The fourth part concerns a Geometric Morphometric investigation performed on two human cranial fossil remains from Melka Kunture, dated to about 850 ka. The two cranial fragments consist in a partial left parietal (MK73/GOM II- 6769; formally Melka Kunture 1, or MK1) and a right portion of the frontal bone (MK76/GOM II - 576, or MK2). Specifically, evenly-spaced semilandmark sets were used acquired along the sagittal suture and the inferior temporal line on MK1 and MK2 respectively. The results of the analyses, in agreement with the chronology of the fossils, represent at present, evidence of one of the best candidates to be the most ancient example of H. heidelbergensis.
The fifth part treats with the external morphology of the cranial base in extant and living Hominoids in relation to ontogenetic, allometric, locomotor and phylogenetic factors. The sample selected consists of 3D landmark configurations acquired on specimens (male and female) including infant, sub-adult and adult individuals. The centroid size of the landmark set configuration was used as indicator of size while the pattern of dental eruption (at death) was used to define six age groups. The relation between morphology and locomotion was explored through the estimation of the position of the foramen magnum along the Frankfurt plane.
Finally, a phylogenetic tree was build using molecular and paleontological data, with the phylogenetic signal investigated through centroid size and shape
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
Tricomi ghiandolari in Camptotheca acuminata Decne (Nyssaceae): natura chimica del secreto, morfologia, struttura e distribuzione.
No full textVariations 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
Immunocytochemical characterisation of endophytic bacteria Azospirillum brasilense, Herbaspirillum seropedicae, Burkholderia ambifaria and Gluconacetobacter diazotrophicus
No full textIn the present work an immunocytochemical characterisation of four endophytic bacterial species has been made by using polyclonal antiserum produced against each of the four bacterial strains previously heated at 60 °C. The aim of this research is to identify common elements among bacteria associated with their endophytic behaviour. Analysis of extracts of each strain by immunoblotting and ELISA confirmed the presence of proteins from different bacterial strains made up of common epitopes. However, antisera produced against Herbaspirillum seropedicae and Burkholderia ambifaria show a high number of bands recognised on each extracts, while antisera against Azospirillum brasilense and Gluconacetobacter diazotrophicus show a low number of bands recognised on each extract. Immunogold labelling showed that epitopes are located both on the cell wall and in the cytoplasm; most likely they could be precursor cell wall proteins synthesized inside the cytoplasm and subsequently transported onto cell wall. Finally, the common bands among bacterial strains revealed by immunoblotting could play a role as active hydrolases involved in host tissue penetration
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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