GIUSEPPE CASTELLI
SKILLS
Academic & Professional Competencies
MICRO-CT SCANNING
Positioning, scanning, data set & volumetric reconstruction.
By working as a research lab assistant in the Palaeoanthropology Lab Giuseppe gained competencies aimed to use the Bruker Skyscan 1273 micro-CT scanner and generate projection data on a daily basis. Samples have often various size and density, and they consist of bone fragments and teeth, as well as complete or fragmented crania and mandibles, worked and non-worked flint flakes/handaxes, pottery fragments, and fossilised remains of palaeoanthropological or palaeontological interest.
CT SCANS RENDERING & SEGMENTATION
Selection & extraction of outer/inner features.
Usually, the reconstructed images from CT scanning need to be segmented for research purposes. The segmentation involves selection and extraction of specific features to allow metric and non-metric statistical analyses. Through this process it is possible to isolate each structure from surrounding elements and generate 3D models. Thanks to specific deep-lerning algorithms, the segmentation is usually an automated procedure. However, in the case of archaeological or palaeoanthropological remains, the software is not able to distinguish between features that have similar densities sometimes. As such, the manual segmentation is often required, which means to physically select each single pixel slice by slice and then interpolate to extract the final elements for statistical analyses.
3D SURFACE SCANNING & POST-PROCESSING
From point cloud to 3D mesh.
Over the course of his career and academic studies, Giuseppe has always dealt with the generation of 3D models by using multiple photogrammetry techniques and surface scanners. As a student, he first used the David Laser Scanner to scan Mesolithic skeletal remains from Sicilian archaeological contexts and perform geometric morphometrics. After his postgraduate studies, he continued using many 3D scanners, such as Artec, Polyga and Leica scanners, and contributed to multiple projects involving the creation of 3D models for curatorial and research purposes or statistical analysis through the use of landmarks and semi-landmarks placed on the generated 3D meshes.
3D IMAGING & PRINTING
3D replicas from digital 3D models.
The Palaeoanthropology Lab houses two very accurate 3D printers working with PLA/ABS filament and resin. In Palaeoanthropology, many fossils and skeletal elements are unique and the original specimens are not easily accessible. Making replicas of these specimens is gradually becoming more and more important in research. 3D printed replicas can be used for many purposes - such as teaching, seminars, conferences, exhibition, research and outreach programmes - and many areas of study, not only Palaeoanthropology (e.g. archaeology, medicine, dentistry, engineering, etc.).
GEOMETRIC MORPHOMETRICS
Collection of coordinates.
Geometric morphometric (GMM) is a technique that allows to study scale and shape relationships of structures using Cartesian geometric coordinates. Landmark and semilandmark coordinates placed on the x, y and z axes are capable of capturing morphologically distinct shape variables. In Palaeoanthropology this approach is particularly useful to determine the biological distance from a species to another or identify differences between anatomical structures. One of the first tools used to capture these sets of coordinates from the surface of original specimens was the microscribe digititiser. This tool is still in use but many cutting-edge structured light and laser scanners have progressively replaced it because they are able to capture geometry and texture both at the same time in a more efficient manner.
STATISTICAL ANALYSIS
Drawing conclusions & estimating values.
Since the nineteenth century, studies about human fossil record and human skeletal variation have been conducted by collecting measurements (Boas 1899) for quantitative analyses. Today, multivariate statistical analyses are becoming increasingly common in palaeoanthropology, facilitated by powerful personal computers and statistical computer software. Some of the most commonly used multivariate techniques to analyze linear and angular measurements are: (i) principal components analysis (PCA); (ii) canonical discriminant functions analysis (also called canonical variates analysis (CVA); (iii) hierarchical cluster analysis; (iv) principal coordinate analysis (PCO); and (v) multidimensional scaling (MDS).
ARCHAEOLOGICAL & OSTEOLOGICAL REPORT WRITING
Writing about Science.
Palaeoanthropologists and archaeologists use data compiled from research and fieldwork to document and report on archaeological sites, surveys or palaeoanthropological findings. By working as a Project Manager and as a researcher at the same time, Giuseppe often deals with reports and scientific papers to share the results of the study with the scientific community.
