Portrait of Dr Julieta G. García-Donas

Dr Julieta G. García-Donas

Lecturer in Biological and Forensic Anthropology

About

Dr Julieta G. García-Donas is a forensic anthropologist with an interest in bone histological analysis for forensic identification purposes and the development of biometric standards for Mediterranean populations. She completed her studies at the University of Edinburgh where she received a MSc in Forensic Anthropology and was awarded with a PhD based on forensic age estimation using rib histomorphometry. Julieta has been involved with different international institutions (Forensic Institute of Tirana - Ministry of Justice of Albania, and Pathology Division -Heraklion, Greece) and carried out field work/research in Spain, Greece and Cyprus. 

Research interests

Dr García-Donas' area of expertise comprises different research interests related to Biological and Forensic Anthropology. Her main research topics relate to inter-population skeletal variation, biometric standards, mainly in Southern European populations, and bone biology and histology. In Julieta's work, there is a special interest in the development of standards for identification of individuals from Mediterranean populations with a special contribution on metric analysis for the estimation of sex and ancestry. 

One of Dr García-Donas' specialities consists of the application of histological methods to estimate age and for the identification of pathological conditions through cortical bone microscopic features. Julieta also investigates the validation of existing forensic methods for positive identification (both macroscopic and microscopic approaches) and other more technical areas as the revision of methodologies related to the preparation of thin-sections for histological assessment.

Teaching

  • SE302: Foundations of Biological Anthropology
  • SE533: Project in Anthropological Science
  • SE308: Skills in Anthropology & Conservation
  • SE570: Current Issues in Evolutionary Anthropology
  • SE992: AUT: Advanced Topics in Evolutionary Anthropology
  • SE307: Thinkers and Theories
  • SE569: Palaeopathology
  • SE609: Forensic Anthropology
  • SE561: Biology and Human Identity
  • SE816: Methods for Forensic Identification
  • SE815: Forensic Taphonomy
  • SE818: Field Excavation and Recovery Methods

Publications

Article

  • Kranioti, E., García-DonasJ., Karell, M., Cravo, L., Ekizoglu, O., Apostol, M. and Cunha, E. (2019). Metric variation of the tibia in the Mediterranean: implications in forensic identification. Forensic Science International [Online]. Available at: DOI: 10.1016/j.forsciint.2019.03.044.
    Ancestry estimation from skeletal remains is a challenging task, but essential for the creation of a complete biological profile. As such, the study of human variation between populations is important for the fields of biological and forensic anthropology, as well as medicine. Cranial and dental morphological variation have traditionally been linked to geographic affinity resulting in several methods of ancestry estimation, while the postcranial skeleton has been systematically neglected. The current study explores metric variation of the tibia in six Mediterranean populations and its validity in estimating ancestry in the Mediterranean. The study sample includes 909 individuals (470 males and 439 females) from Cyprus, Greece, Italy, Spain, Portugal and Turkey. The sample was divided in two subsamples: a reference and a validation sample. Multinomial regression models were created based on the reference sample and then applied to validation sample. The first model used three variables and resulted in 57% and 56% accuracy for the two samples respectively, while the second model (6 variables) resulted in 80% and 74% respectively. Classification between groups ranged from 28% to 95% for the reference sample and from 15% to 91% for the validation sample. The highest classification accuracy was noted for the Greek sample (95% and 90% for the reference and validation sample respectively), followed by the Turkish sample (74% and 78% respectively). The Spanish, Portuguese and Italian samples presented greater morphological overlap which resulted in lower classification accuracies. The results indicate that although the tibia presents considerable variation amongst neighbour populations is not suitable as a sole skeletal element to separate all groups successfully. A combination of different skeletal elements may be required in order to achieve the levels of reliability required for forensic applications.
  • Kranioti, E., García-DonasJ., Can, I. and Ekizoglu, O. (2018). Ancestry estimation based on cranial measurements: a custom made approach. Forensic Science International [Online] 286:265.e1-265.e8. Available at: https://doi.org/10.1016/j.forsciint.2018.02.014.
    The estimation of ancestry is an essential benchmark for positive identification of heavily decomposed bodies that are recovered in a variety of death and crime scenes. This is especially true when reconstructing the biological profile of the deceased as most methods for sex, age and stature estimation are population-specific. Ancestry estimation methods vary from traditional morphological assessment of cranial features and biometric quantification to computer-aided shape analysis and classification with specialised software. The current paper aims to explore population differences between three neighbouring countries (Greece, Cyprus and Turkey) that have been in constant interaction through conflicts and population movements from the ancient past to the present day, through cranial measurements.

    The sample consists of 160 dry crania of Greek origin, 137 dry crania of Greek-Cypriot of origin Cyprus and 380 CT scans from Turks individuals. Twelve measurements were taken in both dry and virtual skulls. Data were submitted to principal component analysis and discriminant function analysis. Intra- and inter-observer error as well as the measurement error between virtual and physical measurements were quantified using TEM, rTEM and R.

    Measurement error was very low in all cases. Classification accuracy for cross-validated data ranged from 74.1 to 97.9%. The highest accuracy was obtained for the Turks sample both in males and females. The results are in accordance with genetic data on the three populations.

    These results create great confidence in the application of the produced functions in forensic cases requiring ancestry estimation in Cyprus, specifically to unidentified individuals from the 1974 conflict. In addition, these standards can be applied in other forensic situations where ethnicity is an issue but the geographic area of origin is limited to the area encompassing Turkey, Cyprus and Greece.
  • Ekizoglu, O., Er, A., Basa, C., Kacmaz, I., Can, I., García-DonasJ. and Elena F, K. (2017). T2-weighted spoiled gradient echo sequence (MERGE): A different perspective on the forensic age estimation. La Revenue de Médecine Légale [Online] 8:189-190. Available at: https://doi.org/10.1016/j.medleg.2017.10.030.
    Introduction

    Age estimation methods using MRI are dependent on staging systems used in T1, T2 and fast spin-echo proton density-weighted sequences. The staging system created by Dedouit [1] from images obtained by fast spin-echo proton density-weighted MRI sequences depends on the assessment of horizontal cartilage hyperintensity. Images obtained by this method, detecting 1.5 mm hyperintensity thickness, and in some cases, detecting continuity of hyperintensity could be challenging. The purpose of this preliminary study was to investigate the utility of T2-weighted spoiled gradient echo sequence in determining the degree of ossification of epiphyses.
    Material and methods

    In this study, fast spin-echo proton density-weighted and MERGE T2-weighted spoiled gradient echo sequences of the knee of 25 patients (10–30 years, 10 female and 15 male) were evaluated using Dedouit et al.’s [1] five-stage method.
    Results

    The horizontal cartilages assessed with MERGE exhibited hyperintensity and clearly visible borders (Fig. 1). Stage 2 and 3 were easily distinguishable and the epiphyseal scar line observed in stage 5 (complete fusion) was easily observed in contrast to the fast spin-echo proton density-weighted sequence. The hyperintense line that was assessed in fast spin-echo proton density-weighted sequence in stage 3 cases was seen as continuous and intermittent hypointense line in MERGE sequence. It was suggested that substages may be necessary for the distinction of stage 3 and 4.
    Discussion

    At present, due to the ethical concerns, non-ionized methods (ultrasound and MRI) are more frequently used in living individuals’ age estimations. MRI assessments in spoiled T2-weighted spoiled gradient echo sequence for age determination may be advantageous in the examination of epiphyseal lines and may produce different options in staging
  • Garcia-Donas, J., Dalton, A., Chaplin, I. and Kranioti, E. (2017). A revised method for the preparation of dry bone samples used in histological examination: Five simple steps. HOMO - Journal of Comparative Human Biology [Online] 68:283-288. Available at: 10.1016/j.jchb.2017.07.001.
    Histology of dry bone tissue has many scientific applications. The histological analysis of bone requires the production of good quality thin sections. Many researchers have developed new histological techniques and/or they have refined existing ones. In this paper, we describe a revision of histological techniques for obtaining thin sections from modern dry bone. The method is easy to apply and the equipment required is commonly found in a histology laboratory. In comparison to other techniques presented in the literature, this adapted method reduces the number of consumables and steps, thereby improving the efficiency and cost-effectiveness of the procedure.
  • Garcia-Donas, J., Ekizoglu, O., Er, A., Bozdag, M., Akcaoglu, M., Can, I. and Kranioti, E. (2017). Accuracy and reliability of Southern European standards for the tibia: a test of two Mediterranean population. Forensic Science and Criminology [Online]. Available at: https://doi.org/10.15761/FSC.1000107.
    Sexual dimorphic variation between populations must be taken into consideration when applying existing methods on unrelated samples. Validation studies are extremely important to avoid misclassification and ensure high quality standards.

    This paper presents a test of a Southern European metric method on Greek-Cypriots (N=132) and Turkish (N=203). Three tibia measurements were taken, sex differences were explored using a Wilcoxon test and the parameters were applied to the original discriminant functions.

    The results showed accuracy rates ranging from 79 to 86% for Greek-Cypriots and from 80 to 88% for Turkish. Differences in the performance of the formulae applied were observed between the samples. Correct classification rates are very similar to the ones reported by the original method.

    This study demonstrates that the application of the Southern European method to estimate sex on these two Mediterranean populations is reliable. A larger and more diverse sample is required to verify our results.
  • Kranioti, E., García-DonasJ., Prado, A., Kyriakou, X. and Langstaff, H. (2016). Sex estimation of the Tibia in Greek-Cypriots and Cretans: forensic applications. Forensic Science International. Forensic Science International [Online]:129.e1-129.e7. Available at: doi: 10.1016/j.forsciint.2016.11.018.
    Sex estimation is an essential step in the identification process of unknown heavily decomposed human remains as it eliminates all possible matches of the opposite sex from the missing person's database. Osteometric methods constitute a reliable approach for sex estimation and considering the variation of sexual dimorphism between and within populations; standards for specific populations are required to ensure accurate results. The current study aspires to contribute osteometric data on the tibia from contemporary Greek-Cypriots to assist the identification process. A secondary goal involves osteometric comparison with data from Crete, a Greek island with similar cultural and dietary customs and environmental conditions. Left tibiae from one hundred and thirty-two skeletons (70 males and 62 females) of Greek-Cypriots and one hundred and fifty-seven skeletons (85 males, 72 females) of Cretans were measured. Seven standard metric variables including Maximum length (ML), Upper epiphyseal breadth (UB), Nutrient foramen anteroposterior diameter (NFap), Nutrient Foramen transverse diameter (NFtrsv), Nutrient foramen circumference (NFCirc), Minimum circumference (MinCirc) and Lower epiphyseal breadth (LB) were compared between sexes and populations. Univariate and multivariate discriminant functions were developed and posterior probabilities were calculated for each sample. Results confirmed the existence of sexual dimorphism of the tibia in both samples as well as the pooled sample. Classification accuracy for univariate functions ranged from 78% to 85% for Greek-Cypriots and from 69% to 83% for Cretans. The best multivariate equations after cross-validation resulted in 87% for Greek-Cypriots and 90% accuracy for Cretans. When the samples were pooled accuracy reached 87% with over 95% confidence for about one third of the population. Estimates with over 95% of posterior probability can be considered reliable while any less than 80% should be treated with caution. This work constitutes the initial step towards the creation of an osteometric database for Greek-Cypriots and we hope it can contribute to the biological profiling and identification of the missing and to potential forensic cases of unknown skeletal remains both in Cyprus and Crete.
  • Ekizoglu, O., A, E., Bozdag, M., Ackaoglu, M., Can, I., García-DonasJ. and Kranioti, E. (2016). Sex estimation of the tibia in modern Turkish: a Computed Tomography study. Legal Medicine [Online]:89-94. Available at: doi: 10.1016/j.legalmed.2016.10.004.
    The utilization of computed tomography is beneficial for the analysis of skeletal remains and it has important advantages for anthropometric studies. The present study investigated morphometry of left tibia using CT images of a contemporary Turkish population. Seven parameters were measured on 203 individuals (124 males and 79 females) within the 19-92-years age group. The first objective of this study was to provide population-specific sex estimation equations for the contemporary Turkish population based on CT images. A second objective was to test the sex estimation formulae on Southern Europeans by Kranioti and Apostol (2015). Univariate discriminant functions resulted in classification accuracy that ranged from 66 to 86%. The best single variable was found to be upper epiphyseal breadth (86%) followed by lower epiphyseal breadth (85%). Multivariate discriminant functions resulted in classification accuracy for cross-validated data ranged from 79 to 86%. Applying the multivariate sex estimation formulae on Southern Europeans (SE) by Kranioti and Apostol in our sample resulted in very high classification accuracy ranging from 81 to 88%. In addition, 35.5-47% of the total Turkish sample is correctly classified with over 95% posterior probability, which is actually higher than the one reported for the original sample (25-43%). We conclude that the tibia is a very useful bone for sex estimation in the contemporary Turkish population. Moreover, our test results support the hypothesis that the SE formulae are sufficient for the contemporary Turkish population and they can be used safely for criminal investigations when posterior probabilities are over 95%.
  • Almeida Prado, P., García-DonasJ., Langstaff, H., Cunha, E., Kyriakou, P. and Kranioti, E. (2016). Os parietale partitum: exploring the prevalence of this trait in four contemporary populations. Journal of Comparative Journal Anatomy [Online] 67:261-272. Available at: https://doi.org/10.1016/j.jchb.2016.04.001.
    Os parietale partitum is a variable segmentation of the parietal bone. This manifests as a parietal division in the anteroposterior or superoinferior planes that is separated by an unusual suture and can be complete or incomplete. The existence of parietal divisions was observed and documented more than 260 years ago. The main objectives of this paper are to record the incidence of this rare trait in four modern populations with no previous records of it and provide a review of the literature. Four contemporary skeletal collections from Crete (Greece), Limassol (Cyprus), Coimbra (Portugal) and Salvador (Brazil) were assessed by the authors of this paper for non-metric cranial traits. Out of 711 skulls, only three cases of parietal division were found and all three originated from the Cypriot collection. These three cases were anatomically analyzed, showing that all three cases were adult females and showed unilateral expression of the trait. Two skulls showed superoinferior division, and the third case showed anteroposterior division. Numerous other cranial non-metric traits were found in these three skulls. Based on the cemetery archives, there seems to be no genetic link between the individuals bearing this trait. Further genetic analysis is suggested in order to verify this conclusion.
  • Garcia-Donas, J., Dyke, J., Paine, R., Despoina, N. and Kranioti, E. (2015). Accuracy and sampling error of two age estimation techniques using rib histomorphometry on a modern sample. Journal of Forensic and Legal Medicine [Online] 38:28-35. Available at: http://dx.doi.org/10.1016/j.jflm.2015.11.012.
    Most age estimation methods are proven problematic when applied in highly fragmented skeletal remains. Rib histomorphometry is advantageous in such cases; yet it is vital to test and revise existing techniques particularly when used in legal settings (Crowder and Rosella, 2007). This study tested Stout & Paine (1992) and Stout et al. (1994) histological age estimation methods on a Modern Greek sample using different sampling sites.

    Six left 4th ribs of known age and sex were selected from a modern skeletal collection. Each rib was cut into three equal segments. Two thin sections were acquired from each segment. A total of 36 thin sections were prepared and analysed. Four variables (cortical area, intact and fragmented osteon density and osteon population density) were calculated for each section and age was estimated according to Stout & Paine (1992) and Stout et al. (1994).

    The results showed that both methods produced a systemic underestimation of the individuals (to a maximum of 43 years) although a general improvement in accuracy levels was observed when applying the Stout et al. (1994) formula. There is an increase of error rates with increasing age with the oldest individual showing extreme differences between real age and estimated age.
    Comparison of the different sampling sites showed small differences between the estimated ages suggesting that any fragment of the rib could be used without introducing significant error. Yet, a larger sample should be used to confirm these results.

Conference or workshop item

  • García-DonasJ., Bonicelli, A., Lill, C., Paine, R. and Kranioti, E. (2019). Age Estimation on Two Mediterranean Populations Using Rib Histomorphology. In: 71th American Academy of Forensic Science Annual Scientific Meeting. AAFS Reference Library, p. 75. Available at: https://www.aafs.org/resources/proceedings/.
    One of the crucial steps for the creation of the biological profile of an individual is the estimation of age at death. The choice of the method depends on the nature of the remains, the equipment available and the expertise of the forensic anthropologist, among others. In cases of very fragmented remains, microscopic methods remain one of the only approaches that can be applied. This study presents the results obtained from a histological analysis of rib thin-sections from two Mediterranean populations.
    The sample consists of 88 standard ribs from two Modern samples (Cretan and Greek-Cypriot Collections, N=88, Mean age=60, SD=17.90). The costal elements were processed histologically according to standard protocols. Thirteen variables (both qualitative and quantitative parameters) were assessed. Technical Error Measurement (TEM) analysis was performed to test the repeatability of the histological parameters. A validation study was performed by applying four existing microscopic methods to verify whether a formula is required for the sample at hand. The correlation between the variables and age was examined through different statistical approaches. The results were used for the generation of linear models using the whole sample and the sample divided by sexes and populations.
    Intra- and inter-observer errors demonstrated that the variables presented different levels of agreement. Three out of four of the methods exhibited a systematic underestimation of the individuals producing high error rates. Most of the variables demonstrated a significant correlation with age and some differences were observed between sexes and samples (Cretans and Greek-Cypriots). A total of 41 models were generated and 12 were selected as the most accurate with a standard error of the estimate ranging from 12 to 8 years. A comparison between the Mediterranean samples and other populations exhibited different patterns on bone remodeling, with the Cretan sample having the lowest Osteon Population Density (OPD) among others.
    This research demonstrates the use of quantitative histology for the estimation of age at death, producing accuracy rates similar to those provided by macroscopic methods. The poor results obtained by the existing histological formulas confirmed the need for a population-specific equation for Cretans and Cypriots. Possible intrinsic and extrinsic factors may be the cause of the observed inter-population variation, with differences in nutrition and genetics being considered as the potential causes. Thus, interesting patterns on remodeling rates provided a new insight on bone histological parameters for the sample under study.

Monograph

  • García-DonasJ., Langstaff, H. and Kranioti, E. (2015). Joan Planells and Via Punica: Demographics of Two Archaeological Populations from Ibiza. Consell Insular de Formentera.
    The anthropological information about past populations allows interpreting the past better and helps to understand biological aspects of the present populations. In this study, the demographics of two Roman archaeological populations from Ibiza are presented. Standard osteological methods are used to assess the populations’ biological profile. Sex and age assessment, stature and pathologies and traumatic lesions are reported. The analysis of cranial, postcranial and dental non-metrics traits skeleton is also undertaken. Overall, this provides valuable
    information about the Roman population from 1st to 7th centuries in the island.
  • Kranioti, E., Langstaff, H. and García-DonasJ. (2015). Cranial Variation in Ibizan Populations. Consell Insular de Formentera.
    This study compares cranial measurements between different populations from Ibiza and other populations from Spain in an attempt to search for evidences of secular changes through time. The similarities and differences between the groups based on craniometrics are reported and discussed. Although the limitations of this study make impossible to draw conclusions, our findings give a new insight into the biological variation in Ibiza.
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