Maria Teresa Ferreira

A new forensic collection housed at the University of Coimbra, Portugal: The 21st century identified skeletal collection

The purpose of this study is to characterize and contextualize the new collection of identified skeletons housed in the Department of Life Sciences at the University of Coimbra, Portugal. The 21st Century Identified Skeletal Collection, which is still being enlarged, is currently composed of 159 complete adult skeletons (age at death range: 29-99 years) of both sexes. The skeletons consist almost exclusively of Portuguese nationals who died between 1995 and 2008. The state of preservation is good and more detailed antemortem information is presently being collected. This collection constitutes a fundamental tool for forensic anthropology research, including development and validation studies of skeletal aging and sexing methods that target elderly adults. Moreover, this collection can also be used in conjunction with the other reference collections housed in the University of Coimbra to investigate secular trends in skeletal development and aging, among others.

Genetic Evidence of African Slavery at the Beginning of the Trans-Atlantic Slave Trade

An archaeological excavation in Valle da Gafaria (Lagos, Portugal), revealed two contiguous burial places outside the medieval city walls, dating from the 15th–17th centuries AD: one was interpreted as a Leprosarium cemetery and the second as an urban discard deposit, where signs of violent, unceremonious burials suggested that these remains may belong to slaves captured in Africa by the Portuguese. We obtained random short autosomal sequence reads from seven individuals: two from the latter site and five from the Leprosarium and used these to call SNP identities and estimate ancestral affinities with modern reference data. The Leprosarium site samples were less preserved but gave some probability of both African and European ancestry. The two discard deposit burials each gave African affinity signals, which were further refined toward modern West African or Bantu genotyped samples. These data from distressed burials illustrate an African contribution to a low status stratum of Lagos society at a time when this port became a hub of the European trade in African slaves which formed a precursor to the transatlantic transfer of millions.

A method for sex estimation using the proximal femur.

The assessment of sex is crucial to the establishment of a biological profile of an unidentified skeletal individual. The best methods currently available for the sexual diagnosis of human skeletal remains generally rely on the presence of well-preserved pelvic bones, which is not always the case. Postcranial elements, including the femur, have been used to accurately estimate sex in skeletal remains from forensic and bioarcheological settings. In this study, we present an approach to estimate sex using two measurements (femoral neck width [FNW] and femoral neck axis length [FNAL]) of the proximal femur. FNW and FNAL were obtained in a training sample (114 females and 138 males) from the Luís Lopes Collection (National History Museum of Lisbon). Logistic regression and the C4.5 algorithm were used to develop models to predict sex in unknown individuals. Proposed cross-validated models correctly predicted sex in 82.5-85.7% of the cases. The models were also evaluated in a test sample (96 females and 96 males) from the Coimbra Identified Skeletal Collection (University of Coimbra), resulting in a sex allocation accuracy of 80.1-86.2%. This study supports the relative value of the proximal femur to estimate sex in skeletal remains, especially when other exceedingly dimorphic skeletal elements are not accessible for analysis.

One for all and all for one: Linear regression from the mass of individual bones to assess human skeletal mass completeness

OBJECTIVES Complete and accurate human skeletal inventory is seldom possible in archaeological and forensic cases involving severe fragmentation. In such cases, skeletal mass comparisons with published references may be used as an alternative to assess skeletal completeness but they are too general for a case-by-case routine analysis. The objective is to solve this issue by creating linear regression equations to estimate the total mass of a skeleton based on the mass of individual bones. MATERIALS AND METHODS Total adult skeletal mass and individual mass of the clavicle, humerus, femur, patella, carpal, metacarpal, tarsal, and metatarsal bones were recorded in a sample of 60 skeletons from the 21st century identified skeletal collection (University of Coimbra). The sample included 32 females and 28 males with ages ranging from 31 to 96 years (mean = 76.4; sd = 14.8). Skeletal mass linear regression equations were calculated based on this sample. RESULTS The mass of individual bones was successfully used to predict the approximate total mass of the adult skeleton. The femur, humerus, and second metacarpal were the best predictors of total skeletal mass with root mean squared errors ranging from 292.9 to 346.1 g. DISCUSSION Linear regression was relatively successful at estimating adult skeletal mass. The non-normal distribution of the sample in terms of mass may have reduced the predictive power of the equations. These results have clear impact for bioanthropology, especially forensic anthropology, since this method may provide better estimates of the completeness of the skeleton or the minimum number of individuals. Am J Phys Anthropol 160:427-432, 2016.

A New Approach for 3D Craniometric Measurements Using 3D Skull Models

This work presents an ongoing work on a new approach to perform craniometric analysis based on contactless 3D modelling of skulls. Beside the acquisition process with a 3D range sensor and initial results in the semi-automatic detection of features in the skulls, we also present some results in the development of a 3D interactive interface that eases interaction for users with little experience on digital 3D manipulation. The final objective is to provide an easy to use 3D interface to allow semi-automatic detection of features in skulls. It is our belief that this system might be the first step towards a new methodology for craniometric analysis that can solve several of the current problems such as repeatability, wide access to skull information or bone damage during measurements.

Application of forensic anthropology to non-forensic issues: an experimental taphonomic approach to the study of human body decomposition in aerobic conditions

Abstract The knowledge of the decomposition process takes a progressively central role in cemetery management. In Europe there is an increase in constructing concrete modules that allow aerobic decomposition, which, theoretically, have advantages. By allowing the circulation of oxygen they will lead to a rapid decomposition, and, consequently, permit burial space rotation. This method also allows the burial of several corpses in small areas. In addition, it solves environmental issues. However, the ways in which the decomposition occurs under these conditions and the time required for skeletonization are still unknown. The aim of this study is to analyse the changes of the cadavers buried in aerobic module systems, realize the time necessary for skeletonization, and study solutions that might enable a faster decomposition. This experimental study utilized three aerobic module systems already used in Portuguese cemeteries and a prototype, with four pig carcasses as animal models. The evolution of the decomposition process was assessed weekly, over 147 days (2184 ADD). This study showed differences in the decomposition process between the four systems. The results allowed us to select the necessary characteristics for the construction of aerobic modules enabling faster decomposition.

Towards automatic non-metric traits analysis on 3D models of skulls

The morphological and metric methods used by anthropologists to assess ancestry can generate results with low repeatability besides damaging the specimens while handling. These problems have led to the development of a new approach based on skulls acquisition with a 3D scanner, using the resulting models to make measurements and morphological analyzes in the CraMs application (Craniometric Measurements). This paper focuses on the development of new methods for the morphological analysis, and the extraction and classification of structures with the objective of reducing inter and intra observer variability. The final aim is to ease the process of estimating the individuals ancestry.

CraMs: Craniometric Analysis Application Using 3D Skull Models

Craniometric analysis plays an important role in anthropology studies and forensics. This paper presents CraMs, an application using a new craniometric approach based on 3D models of the skull. The main objective is to obtain, through a process supervised by anthropologists, the main points of interest used to compute craniometric measurements. The application aids this process by analyzing the skull geometry and automatically providing points of interest. The application also allows for semiautomatic point detection, where the user provides an initial guess that might be refined based on the curvature of the skull, as well as the manual selection of any other points of interest. Moreover, results comparing measurements obtained with CraMs and traditional craniometry methods on eight skulls suggest that the application provides comparable craniometric measurements and lower inter-observer variability. This approach offers advantages such as an easier access to skulls with no risk of bone damage and the possibility of defining new measurements based on morphology or other skull characteristics, which are not possible using traditional methods.