Papers by Francisco Curate
Sample Data used in this investigation were acquired from a Portuguese identified skeletal collec... more Sample Data used in this investigation were acquired from a Portuguese identified skeletal collection, the Coimbra Identified Skeletal Collection (CISC, University of Coimbra, Portugal), comprising 364 individuals (166 females and 198 males). The source of the raw data was the original data set made available by Maria Augusta Neto (1957). Only data from complete left radii were retrieved. Ages at death ranged from 17 to 96 years. Individuals in this sample were born between 1833 and 1918, and died between 1910 and 1936. Data collection Ten measurements (in mm) of the radius were selected, including the maximum length (MLR), minimum circumference in the proximal diaphysis (MCPDR), minimum circumference in the distal diaphysis (MCDDR), transverse diameter of the head (TDHR), sagittal diameter of the head (SDHR), head circumference (HCR), neck circumference (NCR), transverse diameter of the shaft (TDSR), sagittal diameter of the shaft (SDSR), and the inferior epiphysis width (IEWR). All measurements were obtained according to Martin (1928), except the minimum circumference in the proximal diaphysis, defined by Fischer (1906).
Radiogrammetric parameters of the femur were assessed in an adult sample (N=98) from the Coimbra ... more Radiogrammetric parameters of the femur were assessed in an adult sample (N=98) from the Coimbra Identified Skeletal Collection (Portugal). Anteroposterior radiographs of the midshaft area of the left femur of each individual were taken using a mammogram film with an exposure time of mAseg 80-50,exposure of Kv 30-35 and focal distance of 1.0 m. Maximum length of the femur, as defined by Martin and Saller (1957), was determined. Measurements of diaphysis total width (DTW) and medullary width (MW) were taken following a standardized guide. Radiogrammetry was used to establish cortical index (FEMCI) in the femoral mid-shaft. Diaphysis total width (DTW) and femoral cortical index (FEMCI) are significantly higher in males, while medullary width (MW) is not statistically different between sexes. The evaluation of femoral cortical bone reveals sex-specific trajectories of endosteal bone loss and periosteal apposition, stemming from sexual differences in the rate and pattern of bone loss, and in bone size. In females, endocortical bone loss rises with age, particularly in peri- and postmenopausal years, decelerating later in life. Concomitantly, accretion of bone in the subperiosteal surface persists throughout adulthood — partially offsetting bone fragility in women. Strength in the femoral mid-diaphysis appears to be preserved throughout most of the life course in both sexes.
Forensic Science International, Sep 1, 2019
The pelvis is consistently regarded as the most sexually dimorphic region of the human skeleton, ... more The pelvis is consistently regarded as the most sexually dimorphic region of the human skeleton, and methods for sex estimation with the pelvic bones are usually very accurate. In this investigation, population-specific osteometric models for the assessment of sex with the pelvis were designed using a dataset provided by J.A. Serra (1938) that included 256 individuals (131 females and 125 males) from the Coimbra Identified Skeletal Collection and 38 metric variables. The models for sex estimation were operationalized through an online application and decision support system, CADOES. Different classification algorithms generated high accuracy models, ranging from 85% to 92%, with only three variables; and from 85.33% to 97.33%, with all 38 variables. CADOES conveys a probabilistic prediction of skeletal sex, as well as a suite of attributes with educational applicability in the fields of human skeletal anatomy and statistics. This study upholds the value of the pelvis for the estimation of skeletal sex and provides models for that can be applied with high accuracy and low bias.
Medicine Science and The Law, May 11, 2023
The estimation of biological sex is a critical step in the assessment of the biological profile o... more The estimation of biological sex is a critical step in the assessment of the biological profile of an anonymous skeletonized individual. In certain recovery circumstances, the most dimorphic skeletal areas, such as the pelvis, are absent or fragmented; in that case, other bones of the skeleton, including the clavicle and scapula, can be used to predict sex. The purpose of this research is to generate new models for the estimation of sex with clavicular and scapular measurements using a study-sample of 129 individuals with clavicle (65 males and 64 females) and 112 individuals with scapula (50 males and 62 females) from the Lisbon Identified Skeletal Collection (Portugal). A decision tree classifier (C4.5) and logistic regression (LR) were employed to create univariable and multivariable sex prediction models. Accuracy under cross-validation of the classification models is high (up to 93.8%), with minimal bias (<5%), particularly in the multivariable models. The proposed LR models facilitate the probabilistic estimation of biological sex, accounting for the significant overlap in the expression of sexual dimorphism.
Anthropologischer Anzeiger, Aug 27, 2018
In contemporary populations, pregnancy and lactation are usually followed by transient bone loss.... more In contemporary populations, pregnancy and lactation are usually followed by transient bone loss. The observation of reduced bone mass in young females from archaeological sites has sometimes been interpreted as an outcome of reproductive stress. In order to evaluate the overall effect of reproductive dynamics on bone mass in a historical skeletal sample, bone mineral density (BMD) at the proximal femur was assessed by dual-energy X-ray absorptiometry in 78 young women (17-39 years) from the Coimbra Identified Skeletal Collection. BMD was compared within the skeletal sample ("maternal deaths" [ICD-10: chapter XV] vs. "other causes of death", and "married/widowed women" vs. "single women"). Results revealed that mean BMD differences among groups are non-significant, suggesting that a strict reproductive interpretation of premature bone loss in young women from archaeological contexts is not sustained by empirical evidence. Bone mass in young women from archaeological sites should be interpreted as a complex trait stemming from the interplay between reproductive factors, genetics, nutrition, physical activity, and age at menarche.
Archaeological and Anthropological Sciences, Apr 6, 2021
The estimation of biological sex is a primary source of information regarding unidentified skelet... more The estimation of biological sex is a primary source of information regarding unidentified skeletal individuals in bioarcheological and forensic contexts. This study aims to propose new metric standards for the estimation of sex using variables of the calcaneus and talus. An ancillary goal encompasses the creation of a web-based decision support system for the assessment of sex. Six measurements from the talus and nine from the calcaneus were collected from 180 adult individuals (93 females; 87 males) belonging to the Coimbra Identified Skeletal Collection. Logistic regression (LR), support vector machines (SVM), and a decision-tree algorithm were employed to develop models for sex prediction. Univariable sectioning points generated with a decision-tree algorithm yielded an accuracy under cross-validation from 78.3 to 82.2% with talar measurements, and from 73.6 to 86.4% with calcanei variables. Systematic error ranged from 0.2 to 34.1%. Univariable and multivariable models, produced with LR and SVM, correctly predicted sex in 85.0–91.3% of cases (bias from 0.3 to 4.3%). Obtained cross-validated accuracies obtained with the new models are similar to earlier results on the subject. The performance of multivariable model predictive is substantially superior, hinting the relevance of population-specific standards for sex estimation. The operationalization of these models in a free, user-friendly, web-application—CalcTalus (http://osteomics.com/CalcTalus/)—facilitates the probabilistic assessment of sex, providing performance metrics for the statistical templates.
Antropologia portuguesa, Dec 12, 2022
There is a high prevalence of rib fractures in human remains from archaeological contexts, but th... more There is a high prevalence of rib fractures in human remains from archaeological contexts, but these are seldom the focus in paleopathological studies pertaining skeletal trauma. This study aims to document rib fracture patterns in the Coimbra Identified Skeletal Collection, Department of Life Sciences, University of Coimbra. Specific aims of this study included the estimation of rib fracture prevalence in 252 individuals, from both sexes (females: 128; males: 124), with age-at-death varying from 20 to 96 years; and the analysis of the relationship between rib fractures andbiological sex, age-at-death, and bone mineral density measured at the proximal femur. The crude prevalence of rib fractures was 6.3% (N=16); while the true prevalence rate Resumo A prevalência de fraturas das costelas é elevada em contextos arqueológicos, contudo, estas raramente são o foco de estudos paleopatológicos sobre traumatismos esqueléticos. Neste trabalho, pretende-se documentar os padrões de fratura das costelas
The 84th Annual Meeting of the American Association of Physical Anthropologists, St. Louis, MO, 2015
Antropologia portuguesa, 2011
A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso.
Australian Journal of Forensic Sciences, Feb 23, 2020
The femur has been commonly employed for sex determination of human skeletal remains, and it is a... more The femur has been commonly employed for sex determination of human skeletal remains, and it is a suitable alternative to the more sexually dimorphic pelvis when this skeletal region is incomplete or fragmented. The purposes of this study include the evaluation of femoral sexual dimorphism and the generation of specific metric standards for the estimation of sex with the femur in skeletal Brazilian populations. Two hundred femora (130 males and 70 females) of known age at death, sex, and ancestry were used to generate the models for sex prediction. The best estimators of sex were univariable models, including the biomechanical neck length (BNLF, accuracy under cross-validation: 82.5%), the vertical head diameter (VHDL, accuracy under cross-validation: 81.5%), the transverse head diameter (THDF, accuracy under cross-validation: 84.5%), and the epicondylar breadth (EBF, accuracy under cross-validation: 84.5%). In conclusion, a comprehensive anatomical study of the femur in a reference skeletal sample from Brazil was provided, and the value of univariable sex estimators (BNLF, VHDL, THDF and EBF) was established.
Forensic Science International, Jun 1, 2017
The estimation of sex is a central step to establish the biological profile of an anonymous skele... more The estimation of sex is a central step to establish the biological profile of an anonymous skeletal individual. Imaging techniques, including bone densitometry, have been used to evaluate sex in remains incompletely skeletonized. In this paper, we present a technique for sex estimation using the total area (TA) of the proximal femur, a two-dimensional areal measurement determined through densitometry. TA was acquired from a training sample (112 females; 112 males) from the Coimbra Identified Skeletal Collection (University of Coimbra, Portugal). Logistic regression (LR), linear discriminant analysis (LDA), reduce error pruning trees (REPTree), and classification and regression trees (CART) were employed in order to obtain models that could predict sex in unidentified skeletal remains. Under cross-validation, the proposed models correctly estimated sex in 90.2-92.0% of cases (bias ranging from 1.8% to 4.5%). The models were evaluated in an independent test sample (30 females; 30 males) from the 21st Century Identified Skeletal Collection (University of Coimbra, Portugal), with a sex allocation accuracy ranging from 90.0% to 91.7% (bias from 3.3% to 10.0%). Overall, data mining classifiers, especially the REPTree, performed better than the traditional classifiers (LR and LDA), maximizing overall accuracy and minimizing bias. This study emphasizes the significant value of bone densitometry to estimate sex in cadaveric remains in diverse states of preservation and completeness, even human remains with soft tissues.
Elsevier eBooks, 2020
Abstract The popularity of web-based analytical tools with an emphasis on improved statistical an... more Abstract The popularity of web-based analytical tools with an emphasis on improved statistical analyses within the landscape of forensic anthropology is increasing. Osteomics is a web-based platform composed of a suite of forensic decision support systems designed to contend with the challenges posed by the estimation of the biological profile of human skeletal remains and particularly the estimation of age at death, the diagnosis of sex, the calculation of body parameters, and the prediction of biogeographic origin. The web applications designed at Osteomics intend to make innovative and reliable statistical models freely available. The suggested models are grounded around traditional and advanced statistical thinking, data visualization and processing, and predictive modeling under the machine learning paradigm. This paper aims to introduce the potential of the web platforms as forensic decision support systems and to give a detailed description of the statistical techniques used in the web-based applications available at Osteomics.
Journal of Forensic Sciences, Aug 29, 2017
Age at death estimation in adult skeletons is hampered, among others, by the unremarkable correla... more Age at death estimation in adult skeletons is hampered, among others, by the unremarkable correlation of bone estimators with chronological age, implementation of inappropriate statistical techniques, observer error, and skeletal incompleteness or destruction. Therefore, it is beneficial to consider alternative methods to assess age at death in adult skeletons. The decrease in bone mineral density with age was explored to generate a method to assess age at death in human remains. A connectionist computational approach, artificial neural networks, was employed to model femur densitometry data gathered in 100 female individuals from the Coimbra Identified Skeletal Collection. Bone mineral density declines consistently with age and the method performs appropriately, with mean absolute differences between known and predicted age ranging from 9.19 to 13.49 years. The proposed method-DXAGE-was implemented online to streamline age estimation. This preliminary study highlights the value of densitometry to assess age at death in human remains.
The 84th Annual Meeting of the American Association of Physical Anthropologists, St. Louis, MO, 2015
International Journal Of Legal Medicine, May 27, 2022
Forensic sciences, Mar 21, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Revista de Arqueologia
O presente trabalho apresenta novos contributos para a compreensão dos aspectos biológicos e cult... more O presente trabalho apresenta novos contributos para a compreensão dos aspectos biológicos e culturais da população que ergueu e utilizou o Túmulo Megalítico de Santa Rita, localizado no município de Vila Real de Santo António, Portugal. Os ossos estudados são provenientes da câmara funerária, que foi utilizada como espaço funerário secundário e coletivo durante o Calcolítico, entre o final do IV milênio a.n.e. (antes da nossa era) e o segundo quarto do III milênio a.n.e., correspondendo ao primeiro ciclo de ocupação do monumento. Analisou-se o processo tafonômico de modificação do espólio osteológico humano, dados demográficos (sexo e idade à morte), características morfológicas e paleopatológicas da população inumada e o tratamento funerário praticado no ossuário.
This study aims to investigate patterns of femoral cortical bone fragility with age (at death) an... more This study aims to investigate patterns of femoral cortical bone fragility with age (at death) and to evaluate its associations with sex and bone mineral density. Radiogrammetric parameters of the femur and bone mineral density at the proximal femur were assessed in an adult sample (N=98) from the Coimbra Identified Skeletal Collection (Portugal). Diaphysis total width (DTW), femoral cortical index (FEMCI) and bone mineral density (BMD) are significantly higher in males, while medullary width (MW) is not statistically different between sexes. Cortical bone parameters of the femoral diaphysis are associated with age only in women, whereas BMD decreases with age in both sexes. The evaluation of femoral cortical bone reveals sex-specific trajectories of endosteal bone loss and periosteal apposition, stemming from sexual differences in the rate and pattern of bone loss, and in bone size. In females, endocortical bone loss rises with age, particularly in peri- and postmenopausal years, d...
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Papers by Francisco Curate
O tema suscitou bastante interesse entre a comunidade de investigadores presente, tendo a sua discussão originado propostas de novas vertentes de estudo complementar. O trabalho resultou de um projecto pluridisciplinar que integrou arqueólogos da Câmara Municipal de Almada, antropólogos do Centro de Investigação em Antropologia e Saúde do Departamento de Ciências da Vida da Universidade de Coimbra e uma médica do Serviço de Pediatria da Unidade de Neonatologia do Hospital Garcia de Orta (Almada).
An aged (50+ years) male exhumed in the church of Nossa Senhora da Anunciada (Setúbal, Portugal, 1531-1829 AD) presented a well-healed fracture in the right proximal femur. The macroscopic observation revealed a lesion in the intertrochanteric ridge with new bone deposition, and shortening and posterior rotation of the femoral neck. Secondary alterations include the overall shortening of the femur and extensive bone formation in the ilipsoas insertion site at the lesser trochanter – but not osteoarthritis. The described fracture is consistent with an extracapsular fracture of the hip, of the intertrochanteric type 1 (stable, single fracture line without displacement). The extensive bone remodeling in the affected femoral region suggests long-time survival after fracture, and familial and/or community care during recovery.
To determine whether manual labour reduces risk of osteoporosis, by increasing maximal bone mineral density.
Methods: Male skeletons from the Coimbra identified skeletal aged 20+ at death were recorded for entheseal change presence using the new Coimbra method for recording (n=249). These skeletons have known sex, age-at-death, cause of death and occupation and lived between 1826-1938. Occupations were categorised as: heavy manual, manual, non-manual and soldiers following standard methods. Radiogrammetry in a subset of these individuals (n=147) was used to calculate the second metacarpal cortical index. In a smaller subset (n=126) bone mineral density was measured in the left proximal femur using dual x-ray absorptiometry at several sites (dry rice surrounding the bone was used as a soft tissue substitute).
Results: Logistic regression showed no effect (p<0.05) of occupation on total bone mineral density, bone mineral density at the femoral neck or metacarpal cortical index. Total bone mineral density was found to have an effect on some types of entheseal change presence, but this was not statistically significant when age was taken into account. Metacarpal cortical index was found to have a minimal impact on some entheseal changes: mineralisation (Chi2=4.65, p=0.03, df=-1, Nagelkerke pseudo R2=0.06) and erosions (Chi2 =7.46 , p=0.006, df=-1, Nagelkerke pseudo R2=0.09) even when age was taken into account.
Conclusions: Occupation was expected to have an impact on bone mineral density and many of the individuals in this study undertook heavy manual labour. The fact that this showed no effect may be due to socio-economic factors, such as poor nutrition. It is possible that rotator cuff entheseal changes, particularly erosions may be impacted by localised low bone mineral density not captured by this study. Further research is needed to study the relationship between osteoporosis and cross-sectional geometry, which may be a better indicator of loading than occupation.
Funding: Fundação para a Ciência e a Tecnologia SFRH/BPD/82559/2011, SFRH/BPD/74015/2010.