Publications by authors named "Frédéric Santos"

21 Publications

  • Page 1 of 1

An ecological niche shift for Neanderthal populations in Western Europe 70,000 years ago.

Sci Rep 2021 Mar 5;11(1):5346. Epub 2021 Mar 5.

University of Bordeaux, CNRS, MCC, PACEA, UMR 5199, Bâtiment B2, Allée Geoffroy St. Hilaire, CS 50023, 33600, Pessac, France.

Middle Paleolithic Neanderthal populations occupied Eurasia for at least 250,000 years prior to the arrival of anatomically modern humans. While a considerable body of archaeological research has focused on Neanderthal material culture and subsistence strategies, little attention has been paid to the relationship between regionally specific cultural trajectories and their associated existing fundamental ecological niches, nor to how the latter varied across periods of climatic variability. We examine the Middle Paleolithic archaeological record of a naturally constrained region of Western Europe between 82,000 and 60,000 years ago using ecological niche modeling methods. Evaluations of ecological niche estimations, in both geographic and environmental dimensions, indicate that 70,000 years ago the range of suitable habitats exploited by these Neanderthal populations contracted and shifted. These ecological niche dynamics are the result of groups continuing to occupy habitual territories that were characterized by new environmental conditions during Marine Isotope Stage 4. The development of original cultural adaptations permitted this territorial stability.
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http://dx.doi.org/10.1038/s41598-021-84805-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7935894PMC
March 2021

The evolution of the vestibular apparatus in apes and humans.

Elife 2020 03 3;9. Epub 2020 Mar 3.

Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.

Phylogenetic relationships among extinct hominoids (apes and humans) are controversial due to pervasive homoplasy and the incompleteness of the fossil record. The bony labyrinth might contribute to this debate, as it displays strong phylogenetic signal among other mammals. However, the potential of the vestibular apparatus for phylogenetic reconstruction among fossil apes remains understudied. Here we test and quantify the phylogenetic signal embedded in the vestibular morphology of extant anthropoids (monkeys, apes and humans) and two extinct apes ( and ) as captured by a deformation-based 3D geometric morphometric analysis. We also reconstruct the ancestral morphology of various hominoid clades based on phylogenetically-informed maximum likelihood methods. Besides revealing strong phylogenetic signal in the vestibule and enabling the proposal of potential synapomorphies for various hominoid clades, our results confirm the relevance of vestibular morphology for addressing the controversial phylogenetic relationships of fossil apes.
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http://dx.doi.org/10.7554/eLife.51261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054002PMC
March 2020

A method of sexing the human os coxae based on logistic regressions and Bruzek's nonmetric traits.

Am J Phys Anthropol 2019 07 15;169(3):435-447. Epub 2019 May 15.

Université de Bordeaux - CNRS - MCC, UMR 5199 PACEA, Pessac, France.

Objectives: This study aims at proposing a visual method for sexing the human os coxae based on a statistical approach, using a scoring system of traits described by Bruzek (2002). This method is evaluated on a meta-population sample, where the data were acquired by direct observation of dry bones as well as computed tomography (CT) scans. A comparison with the original Bruzek's (2002) method is performed.

Materials And Methods: Five hundred and ninety two ossa coxae of modern humans are included in the reference dataset. Two other samples, composed respectively of 518 ossa coxae and 99 CT-scan images, are both used for validation purposes. The individuals come from five European or North American population samples. Eleven trichotomic traits (expressing female, male, or intermediate forms) were observed on each os coxae. The new approach employs statistical processing based on logistic regressions. An R package freely available online, PELVIS, implements both methods.

Results: Both methods provide highly reliable sex estimates. The new statistical method has a slightly better accuracy rate (99.2%) than the former method (98.2%) but has also a higher rate of indeterminate individuals (12.9% vs. 3% for complete bones).

Conclusion: The efficiency of both methods is compared. Low error rates were preferred over high ability of reaching the classification threshold. The impact of lateralization and the asymmetry of observed traits are discussed. Finally, it is shown that this visual method of sex estimation is reliable and easy to use through the graphical user interface of the R package.
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http://dx.doi.org/10.1002/ajpa.23855DOI Listing
July 2019

Diaphysator: An online application for the exhaustive cartography and user-friendly statistical analysis of long bone diaphyses.

Am J Phys Anthropol 2019 06 5;169(2):377-384. Epub 2019 Apr 5.

Laboratory of 3D Imaging and Analytical Methods, Faculty of Natural Sciences, Department of Anthropology and Human Genetics, Charles University, Praha, Czech Republic.

The cross-sectional geometry (CSG) of long bone diaphyses is used in bioanthropology to evaluate their resistance to biomechanical constraints and to infer life-history-related patterns such as mobility, activity specialization or intensity, sexual dimorphism, body mass and proportions. First limited by technical analytical constraints to the analysis of one or two cross sections per bone, it has evolved into the analysis of cross sections of the full length of the diaphyseal part of long bones. More recently, researchers have developed analytical tools to map the cortical thickness of entire diaphyses to evaluate locomotor signatures. However, none of these analytical tools are easy to use for scientists who are not familiar with computer programming, and some statistical procedures-such as mapping the correlation coefficients of the diaphyseal thickness with various parameters have yet to be made available. Therefore, we developed an automated and open-source application that renders those analyses (both CSG and cortical thickness) in a semiautomated and user friendly manner. This application, called "Diaphysator", is associated with another free software ("Extractor", presented in Dupej et al. (2017). American Journal of Physical Anthropology, 164, 868-876). Diaphysator can be used as an online application (https://diaphysator.shinyapps.io/maps) or as a package for R statistical software. Along with the mean maps of cortical thickness and mean CSG parameter graphs, the users can evaluate the correlations and partial correlations of both CSG parameters at every cross section along the diaphyseal length, and cortical thickness data points of the entire diaphysis, with any factor such as age, sex, stature, and body mass.
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http://dx.doi.org/10.1002/ajpa.23835DOI Listing
June 2019

Architecture of the femoral and tibial diaphyses in relation to body mass and composition: Research from whole-body CT scans of adult humans.

Am J Phys Anthropol 2018 12 24;167(4):813-826. Epub 2018 Oct 24.

Laboratory of 3D Imaging and Analytical Methods, Faculty of Natural Sciences, Department of Anthropology and Human Genetics, Charles University, Praha 2, Czech Republic.

Objectives: Recent investigations have evaluated the influence of body composition on long bones in order to overcome the limits of body mass (BM) estimation methods and eventually lead to studying nutrition in past populations. Knowing how fat mass (FM) and fat-free mass (FFM) impact the skeleton would also enhance the understanding of mobility, activity, and locomotion derived from bone architecture. We investigated the relationship between BM and composition, and the architecture of the entire tibial and femoral diaphyses in an adult sample representative of a wide range of variation in age, BM, and composition.

Materials And Methods: Body composition was measured directly from 78 whole-body CT scans for which the age, sex, BM, and stature were recorded. The entire diaphyseal thickness, volume, curvature, and cross-sectional geometry parameters of both the femur and tibia were numerically extracted.

Results: FM correlates with large portions of the femoral thickness in females only. FFM correlates with the femoral diaphysis in males but not in females. FFM correlates with the tibia architecture in both sexes, while FM is correlated in males exclusively.

Discussion: BM and body components influence the architecture of the diaphysis of lower limb long bones in sex-specific patterns that are mostly reflected in their thickness and can be recorded, in some cases, for their strength, rigidity, and volume. Our results suggest that (1) long bone diaphyses should be thoroughly studied, as a whole, when possible; and (2) BM and body components should be accounted for when deriving activity, mobility, or locomotion patterns from cortical bone.
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http://dx.doi.org/10.1002/ajpa.23713DOI Listing
December 2018

Virtual reconstruction of the Upper Palaeolithic skull from Zlatý Kůň, Czech Republic: Sex assessment and morphological affinity.

PLoS One 2018 30;13(8):e0201431. Epub 2018 Aug 30.

Department of Anthropology and Human Genetics, Faculty of Science, Charles University, Prague, Czech Republic.

The incomplete cranium discovered at the Zlatý kůň site in the Bohemian Karst is a rare piece of skeletal evidence of human presence in Central Europe during the Late Glacial period. The relative position of cranial fragments was restored and missing parts of the cranium were virtually reconstructed using mirroring and the Thin-plate splines algorithm. The reconstruction allowed us to collect principal cranial measurements, revise a previous unfounded sex assignment and explore the specimen's morphological affinity. Visual assessment could not reliably provide a sexual diagnosis, as such methods have been developed on modern populations. Using a population-specific approach developed on cranial measurements collected from the literature on reliably sexed European Upper Palaeolithic specimens, linear discriminant analysis confirmed previous assignment to the female sex. However, caution is necessary with regard to the fact that it was assessed from the skull. The Zlatý kůň specimen clearly falls within the range of Upper Palaeolithic craniometric variation. Despite the shift in cranial variation that accompanied the Last Glacial Maximum (LGM), the Zlatý kůň skull exhibits a morphological affinity with the pre-LGM population. Several interpretations are proposed with regard to the complex population processes that occurred after the LGM in Europe.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201431PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6116938PMC
January 2019

Sex-specific functional adaptation of the femoral diaphysis to body composition.

Am J Hum Biol 2018 07 24;30(4):e23123. Epub 2018 Mar 24.

Department of Anthropology and Human Genetics, Faculty of Natural Sciences, Charles University - Viničná 7, 128 43 Prague 2, Czech Republic.

Objectives: The human femoral diaphysis is often used to reconstruct loading histories (mobility, activity, body mass). The proximal femur is known to be differentially affected by changes in total fat-mass (FM), fat-free mass (FFM), and body fat percentage (BF%), but the adaptation of the entire diaphysis to body composition has not been thoroughly characterized to date. Understanding how the femoral diaphysis adapts to body components would benefit biomechanical interpretations of the femoral variation and nutrition-related studies.

Methods: Combining various methods from clinical nutrition, biological anthropology, and geometric morphometrics, we evaluated the correlation of measures taken on the entire femoral diaphysis with estimated FM, FFM, and BF% from 61 CT scans (17 females, 44 males). The sample was predominantly composed of people with obesity.

Results: Cortical area of the cross-sections and local cortical thickness showed high correlation with BF% in particular, in females only. The curvature significantly decreased with FM and BF% in both sexes. The lowest correlations are found with FFM.

Conclusions: The observed sexual dimorphism is consistent with differing aging processes; cortical bone decreases in females through endosteal resorption while it remains almost constant in males who compensate for endosteal resorption by periosteal apposition on the diaphyseal surface. The functional adaptation to compressive forces indicates a systemic endosteal apposition of bone material with increased BF% and FM in females only. FM and BF% are linked to a straighter femur in both sexes, suggesting an optimization of the resistance to compressive loads by distributing them more linearly along the entire diaphysis.
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http://dx.doi.org/10.1002/ajhb.23123DOI Listing
July 2018

Body mass estimation from the skeleton: An evaluation of 11 methods.

Forensic Sci Int 2017 Dec 22;281:183.e1-183.e8. Epub 2017 Nov 22.

Charles University, Laboratory of 3D Imaging and Analytical Methods, Department of Anthropology and Human Genetics, Faculty of Natural Sciences, Viničná 7, 128 43 Prague 2, Czech Republic; Université de Bordeaux, PACEA, UMR 5199, CNRS - Bâtiment B8, Allée Geoffroy Saint Hilaire, CS 50023, F-33400 Talence, France.

Estimating an individual body mass (BM) from the skeleton is a challenge for forensic anthropology. However, identifying someone's BMI (Body Mass Index) category, i.e. underweight, normal, overweight or obese, could contribute to identification. Individual BM is also known to influence the age-at-death estimation from the skeleton. Several methods are regularly used by both archaeologists and forensic practitioners to estimate individual BM. The most commonly used methods are based on femoral head breadth, or stature and bi-iliac breadth. However, those methods have been created from mean population BMs and are therefore meant to estimate the average BM of a population. Being that they are based on individual BM data and estimated femoral cortical areas, the newest published methods are supposed to be more accurate. We evaluated the accuracy and reliability of the most commonly used and most recent BM estimation methods (n=11) on a sample of 64 individuals. Both sexes and all BMI categories are represented, as well as a wide range of BM. Ages in this sample range from 20 to 87 years of age. Absolute and real differences between actual BM and estimated BM were assessed; they determined the accuracy for individual BM estimation and for average BM estimation of a population, respectively. The proportion of the sample whose estimated BM falls within ±10% and ±20% of their actual BM determines the reliability of the methods in our sample for, respectively, individual BM estimation and average BM of a population. The tested methods result in an absolute difference of 11kg-26kg±10kg with regards to prediction of individuals actual BM. The real differences are very variable from method to method, ranging from -14kg to 25kg. None of the tested methods is able to estimate BM of half of the sample within ±10% of their actual BM but most of them can estimate BM of more than half of the sample within ±20% of their actual BM. The errors increase with increasing BM, demonstrating a bias in all the methods. No bone variable tested correlated with BM. BMI categories were correctly predicted for less than 50% of the sample in most cases. In conclusion, our study demonstrates that the 11 methods tested are not suited for estimating individual BM or for predicting BMI categories. However, they are accurate and reliable enough for estimating the average BM of a population.
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http://dx.doi.org/10.1016/j.forsciint.2017.10.026DOI Listing
December 2017

AnthropMMD: An R package with a graphical user interface for the mean measure of divergence.

Am J Phys Anthropol 2018 01 10;165(1):200-205. Epub 2017 Oct 10.

Université de Bordeaux - CNRS - MCC, UMR 5199 PACEA, Pessac, F-33600, France.

The mean measure of divergence is a dissimilarity measure between groups of individuals described by dichotomous variables. It is well suited to datasets with many missing values, and it is generally used to compute distance matrices and represent phenograms. Although often used in biological anthropology and archaeozoology, this method suffers from a lack of implementation in common statistical software. A package for the R statistical software, AnthropMMD, is presented here. Offering a dynamic graphical user interface, it is the first one dedicated to Smith's mean measure of divergence. The package also provides facilities for graphical representations and the crucial step of trait selection, so that the entire analysis can be performed through the graphical user interface. Its use is demonstrated using an artificial dataset, and the impact of trait selection is discussed. Finally, AnthropMMD is compared to three other free tools available for calculating the mean measure of divergence, and is proven to be consistent with them.
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http://dx.doi.org/10.1002/ajpa.23336DOI Listing
January 2018

Validation and reliability of the sex estimation of the human os coxae using freely available DSP2 software for bioarchaeology and forensic anthropology.

Am J Phys Anthropol 2017 10 17;164(2):440-449. Epub 2017 Jul 17.

Centre for Functional Ecology, Laboratory of Forensic Anthropology, Life Sciences Department, University of Coimbra, Coimbra, 3000-456, Portugal.

Objectives: A new tool for skeletal sex estimation based on measurements of the human os coxae is presented using skeletons from a metapopulation of identified adult individuals from twelve independent population samples. For reliable sex estimation, a posterior probability greater than 0.95 was considered to be the classification threshold: below this value, estimates are considered indeterminate. By providing free software, we aim to develop an even more disseminated method for sex estimation.

Materials And Methods: Ten metric variables collected from 2,040 ossa coxa of adult subjects of known sex were recorded between 1986 and 2002 (reference sample). To test both the validity and reliability, a target sample consisting of two series of adult ossa coxa of known sex (n = 623) was used. The DSP2 software (Diagnose Sexuelle Probabiliste v2) is based on Linear Discriminant Analysis, and the posterior probabilities are calculated using an R script.

Results: For the reference sample, any combination of four dimensions provides a correct sex estimate in at least 99% of cases. The percentage of individuals for whom sex can be estimated depends on the number of dimensions; for all ten variables it is higher than 90%. Those results are confirmed in the target sample.

Discussion: Our posterior probability threshold of 0.95 for sex estimate corresponds to the traditional sectioning point used in osteological studies. DSP2 software is replacing the former version that should not be used anymore. DSP2 is a robust and reliable technique for sexing adult os coxae, and is also user friendly.
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http://dx.doi.org/10.1002/ajpa.23282DOI Listing
October 2017

Detecting menarcheal status through dental mineralization stages?

Am J Phys Anthropol 2016 10 17;161(2):367-73. Epub 2016 Jun 17.

UMR 5199 PACEA, CNRS, University of Bordeaux, Bâtiment B8, Allée Geoffroy Saint Hilaire-CS 50023-F-33400, Talence, France.

Menarche is an indicator frequently used to study variation in growth, development, and related health conditions among members of living populations. As a life event, menarche is often associated with changes in an individual's social identity. The reproductive lifespan, which for females starts with menarche, is a paramount feature of palaeodemographic studies. Determination of menarche status from the skeletal remains of individuals of past populations can be obtained by assessing the developmental status of the iliac crest, as well as the hand and wrist bones, which are, unlike teeth, often poorly recovered in bioarchaeological contexts. The present study seeks to evaluate the link between dental mineralization and menarche in a population of known menarche status. The relationship between permanent teeth mineralization and menarche status was investigated by using data of developing permanent teeth (167 radiographs) rated in accordance with the well-known standards of Demirjian et al. and Moorrees et al. collected among 73 living French females of known menarcheal status. Using correlation ratios, GLMM and CART algorithm, menarcheal status is correlated with mineralization of the premolars. Menarcheal status is predicted correctly for 92 and 77% of radiographs of the learning and validation samples, respectively. Although promising, the results require caution prior to generalization to other populations. The age of menarche in this particular sample may simply coincide with the development of the premolars in this particular sample. Therefore, further investigation applied to populations with various mean ages of menarche is required in order to provide new evidence of variation in human growth and development from the correspondence between the mineralization of the permanent teeth and menarche.
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http://dx.doi.org/10.1002/ajpa.23027DOI Listing
October 2016

Early Neanderthal constructions deep in Bruniquel Cave in southwestern France.

Nature 2016 06 25;534(7605):111-4. Epub 2016 May 25.

PACEA, UMR 5199 CNRS-UB-MCC University of Bordeaux, 33615 Pessac, France.

Very little is known about Neanderthal cultures, particularly early ones. Other than lithic implements and exceptional bone tools, very few artefacts have been preserved. While those that do remain include red and black pigments and burial sites, these indications of modernity are extremely sparse and few have been precisely dated, thus greatly limiting our knowledge of these predecessors of modern humans. Here we report the dating of annular constructions made of broken stalagmites found deep in Bruniquel Cave in southwest France. The regular geometry of the stalagmite circles, the arrangement of broken stalagmites and several traces of fire demonstrate the anthropogenic origin of these constructions. Uranium-series dating of stalagmite regrowths on the structures and on burnt bone, combined with the dating of stalagmite tips in the structures, give a reliable and replicated age of 176.5 thousand years (±2.1 thousand years), making these edifices among the oldest known well-dated constructions made by humans. Their presence at 336 metres from the entrance of the cave indicates that humans from this period had already mastered the underground environment, which can be considered a major step in human modernity.
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http://dx.doi.org/10.1038/nature18291DOI Listing
June 2016

A Non-Destructive Method for Distinguishing Reindeer Antler (Rangifer tarandus) from Red Deer Antler (Cervus elaphus) Using X-Ray Micro-Tomography Coupled with SVM Classifiers.

PLoS One 2016 22;11(2):e0149658. Epub 2016 Feb 22.

Travaux et Recherches Archéologiques sur les Cultures, les Espaces et les Sociétés-UMR 5608, University Toulouse Jean Jaurès, Toulouse, France.

Over the last decade, biomedical 3D-imaging tools have gained widespread use in the analysis of prehistoric bone artefacts. While initial attempts to characterise the major categories used in osseous industry (i.e. bone, antler, and dentine/ivory) have been successful, the taxonomic determination of prehistoric artefacts remains to be investigated. The distinction between reindeer and red deer antler can be challenging, particularly in cases of anthropic and/or taphonomic modifications. In addition to the range of destructive physicochemical identification methods available (mass spectrometry, isotopic ratio, and DNA analysis), X-ray micro-tomography (micro-CT) provides convincing non-destructive 3D images and analyses. This paper presents the experimental protocol (sample scans, image processing, and statistical analysis) we have developed in order to identify modern and archaeological antler collections (from Isturitz, France). This original method is based on bone microstructure analysis combined with advanced statistical support vector machine (SVM) classifiers. A combination of six microarchitecture biomarkers (bone volume fraction, trabecular number, trabecular separation, trabecular thickness, trabecular bone pattern factor, and structure model index) were screened using micro-CT in order to characterise internal alveolar structure. Overall, reindeer alveoli presented a tighter mesh than red deer alveoli, and statistical analysis allowed us to distinguish archaeological antler by species with an accuracy of 96%, regardless of anatomical location on the antler. In conclusion, micro-CT combined with SVM classifiers proves to be a promising additional non-destructive method for antler identification, suitable for archaeological artefacts whose degree of human modification and cultural heritage or scientific value has previously made it impossible (tools, ornaments, etc.).
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0149658PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4762490PMC
July 2016

In situ study of the Gravettian individual from Cussac cave, locus 2 (Dordogne, France).

Am J Phys Anthropol 2015 Dec 2;158(4):759-68. Epub 2015 Sep 2.

CNRS, Anthropologie des Populations Passées et Présentes, UMR 5199 PACEA, Batiment B8, Allée Geoffroy Saint Hilaire, Université De Bordeaux, CS, 50023, Pessac Cedex, France, 33615.

Objectives: Cussac cave, discovered in 2000, is characterized by the exceptional presence of monumental engravings and human remains deposited in bear nests. Both the style of the art and a direct radiocarbon date indicate a Gravettian age. As the cave is protected as a national heritage site, only very limited access to and restricted direct interventions involving the human remains are possible. Here, we present the results of observations and measurements of Cussac L2A, represented by a virtually complete skeleton covered with a layer of clay.

Materials And Methods: A portion of the clay that covered some bones was removed in order to undertake a study of the skeleton in situ. The age-at-death was assessed using several indicators, especially changes on the auricular surface of the ilium. The sex was assessed using the morphology and morphometrics of the coxal bones. Cussac L2A stature, humero-femoral index, and crural index were also estimated. The dimensions of the Cussac L2A skeletal remains are compared with the other European Gravettian and Late Upper Paleolithic human remains using adjusted Z-Scores.

Results: The analysis indicates that Cussac L2A is probably a male who died aged between 20 and 50 years. If the sex assessment is correct, with an averaged estimated stature of 1.64 m, Cussac L2A would be one of the shorter Gravettian males.

Discussion: These results raise the importance of the new discoveries to better understand the variability of Upper Paleolithic skeletal morphology and stress the difficulties in marrying heritage preservation and scientific investigations.
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http://dx.doi.org/10.1002/ajpa.22831DOI Listing
December 2015

Statistical sex determination from craniometrics: Comparison of linear discriminant analysis, logistic regression, and support vector machines.

Forensic Sci Int 2014 Dec 13;245:204.e1-8. Epub 2014 Oct 13.

University Bordeaux-CNRS-MCC, PACEA, UMR 5199, F-33615 Pessac, France; Charles University, Faculty of Science, Department of Anthropology and Human Genetics, Prague, Czech Republic; West Bohemia University, Faculty of Humanities, Department of Anthropology, Plzen, Czech Republic.

Accuracy of identification tools in forensic anthropology primarily rely upon the variations inherent in the data upon which they are built. Sex determination methods based on craniometrics are widely used and known to be specific to several factors (e.g. sample distribution, population, age, secular trends, measurement technique, etc.). The goal of this study is to discuss the potential variations linked to the statistical treatment of the data. Traditional craniometrics of four samples extracted from documented osteological collections (from Portugal, France, the U.S.A., and Thailand) were used to test three different classification methods: linear discriminant analysis (LDA), logistic regression (LR), and support vector machines (SVM). The Portuguese sample was set as a training model on which the other samples were applied in order to assess the validity and reliability of the different models. The tests were performed using different parameters: some included the selection of the best predictors; some included a strict decision threshold (sex assessed only if the related posterior probability was high, including the notion of indeterminate result); and some used an unbalanced sex-ratio. Results indicated that LR tends to perform slightly better than the other techniques and offers a better selection of predictors. Also, the use of a decision threshold (i.e. p>0.95) is essential to ensure an acceptable reliability of sex determination methods based on craniometrics. Although the Portuguese, French, and American samples share a similar sexual dimorphism, application of Western models on the Thai sample (that displayed a lower degree of dimorphism) was unsuccessful.
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http://dx.doi.org/10.1016/j.forsciint.2014.10.010DOI Listing
December 2014

Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

J Forensic Sci 2014 Nov 3;59(6):1502-16. Epub 2014 Aug 3.

Université Bordeaux 1, UMR 5199 PACEA, CNRS, MCC, Anthropologie des Populations Passées et Présentes, F-33615, Pessac, France; Joint POW/MIA Accounting Command, Central Identification Laboratory, 310 Worchester Ave, Bldg 45, USA-96853, Joint Base Pearl Harbor-Hickam, HI.

This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.
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http://dx.doi.org/10.1111/1556-4029.12547DOI Listing
November 2014

Facial soft tissue depths in French adults: variability, specificity and estimation.

Forensic Sci Int 2013 Sep 14;231(1-3):411.e1-10. Epub 2013 May 14.

Université Bordeaux 1, UMR 5199 PACEA, Anthropologie des Populations Passées et Présentes, avenue des Facultés, bât. B8, F-33405 Talence, France.

Facial soft tissue depths (FSTD) are used in facial approximation to render the shape of the face, and are traditionally published specifically to population, corpulence, and sex amongst other factors. This paper investigates the variability of FSTD collected at 37 landmarks on 500 CT (computed tomography) scans of French living individuals. The specificity of the sample is evaluated by comparing values with six published datasets of various populations and recording techniques. Apart from a significant influence of the corpulence, FSTD show negligible variations with age and sex. The differences between the French sample and other datasets contradict the hypothesis of major influence of population, and underline sample specificity linked with technique and methodology of data measurement. Regression equations were computed to estimate FSTD using age, sex, facial build, and craniometrics, leading to more accurate results if such factors are known. Nevertheless, application of the pooled T-table (Tallied-Facial-Soft-Tissue-Depth-Data) has been validated according to the French sample.
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http://dx.doi.org/10.1016/j.forsciint.2013.04.007DOI Listing
September 2013

Life history of the individuals buried in the St. Benedict Cemetery (Prague, 15th-18th centuries): insights from (14)C dating and stable isotope (δ(13)C, δ(15)N, δ(18)O) analysis.

Am J Phys Anthropol 2013 Jun 16;151(2):202-14. Epub 2013 Apr 16.

Laboratoire PACEA - De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie, UMR 5199, CNRS, Université de Bordeaux, 33400 Talence, France.

Funerary practices and bioarchaeological (sex and age) data suggest that a mortality crisis linked to an epidemic episode occurred during the fifth phase of the St. Benedict cemetery in Prague (Czech Republic). To identify this mass mortality episode, we reconstructed individual life histories (dietary and mobility factors), assessed the population's biological homogeneity, and proposed a new chronology through stable isotope analysis (δ(13)C, δ(18)O and δ(15)N) and direct radiocarbon dating. Stable isotope analysis was conducted on the bone and tooth enamel (collagen and carbonate) of 19 individuals from three multiple graves (MG) and 12 individuals from individual graves (IG). The δ(15)N values of collagen and the difference between the δ(13)C values of collagen and bone carbonate could indicate that the IG individuals had a richer protein diet than the MG individuals or different food resources. The human bone and enamel carbonate and δ(18)O values suggest that the majority of individuals from MG and all individuals from IG spent most of their lives outside of the Bohemian region. Variations in δ(18)O values also indicate that all individuals experienced residential mobility during their lives. The stable isotope results, biological (age and sex) data and eight (14)C dates clearly differentiate the MG and IG groups. The present work provides evidence for the reuse of the St. Benedict cemetery to bury soldiers despite the funeral protest ban (1635 AD). The Siege of Prague (1742 AD) by French-Bavarian-Saxon armies is identified as the cause of the St. Benedict mass mortality event.
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http://dx.doi.org/10.1002/ajpa.22267DOI Listing
June 2013

Three-dimensional computer-assisted craniometrics: a comparison of the uncertainty in measurement induced by surface reconstruction performed by two computer programs.

Forensic Sci Int 2012 Jun 31;219(1-3):221-7. Epub 2012 Jan 31.

Université Bordeaux 1, UMR 5199 PACEA, Anthropologie des Populations Passées et Présentes, Talence, France.

Digital investigation of anthropological material through computed tomography (CT) offers several new opportunities in morphometrics. However, an object measured with computer-assisted methods does not necessarily exactly match the original one. The scanning and surface reconstruction of the object induce some alterations, and data acquisition is prone to measurement uncertainty. The purpose of this research is to evaluate the intra- and inter-observers variations in medical CT scan measurements of a known-size phantom and two dry crania. Two software packages, AMIRA and Treatment and Increased Vision for Medical Imaging (TIVMI), which use different techniques of surface reconstructions, were compared. The mean difference between the measurements was lower for TIVMI, using an objective algorithm based on the half-maximum height (HMH) protocol in three dimensions (3D). AMIRA can induce up to a 4% error in known measurements and 5% uncertainty in dry skull measurements. This study emphasises the risk of object shape alteration in each step of its digitisation.
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http://dx.doi.org/10.1016/j.forsciint.2012.01.008DOI Listing
June 2012

The reality of Neandertal symbolic behavior at the Grotte du Renne, Arcy-sur-Cure, France.

PLoS One 2011 29;6(6):e21545. Epub 2011 Jun 29.

Institut National de Recherche en Informatique et en Automatique Bordeaux Sud-Ouest, Institut de Mathématiques de Bordeaux, Université de Bordeaux, Talence, France.

Background: The question of whether symbolically mediated behavior is exclusive to modern humans or shared with anatomically archaic populations such as the Neandertals is hotly debated. At the Grotte du Renne, Arcy-sur-Cure, France, the Châtelperronian levels contain Neandertal remains and large numbers of personal ornaments, decorated bone tools and colorants, but it has been suggested that this association reflects intrusion of the symbolic artifacts from the overlying Protoaurignacian and/or of the Neandertal remains from the underlying Mousterian.

Methodology/principal Findings: We tested these hypotheses against the horizontal and vertical distributions of the various categories of diagnostic finds and statistically assessed the probability that the Châtelperronian levels are of mixed composition. Our results reject that the associations result from large or small scale, localized or generalized post-depositional displacement, and they imply that incomplete sample decontamination is the parsimonious explanation for the stratigraphic anomalies seen in the radiocarbon dating of the sequence.

Conclusions/significance: The symbolic artifacts in the Châtelperronian of the Grotte du Renne are indeed Neandertal material culture.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0021545PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3126825PMC
December 2011

Frequent reduction or absence of detection of the JAK2-mutated clone in JAK2V617F-positive patients within the first years of hydroxyurea therapy.

Haematologica 2008 Nov 25;93(11):1723-7. Epub 2008 Aug 25.

Laboratoire d'Hématologie, Hôpital du Bocage, CHU de Dijon, Dijon, France. francois.girodon@chu-dijon

We analyzed the effect of hydroxyurea on the JAK2V617F allelic ratio (%JAK2V617F), measured in purified blood granulocytes, of patients with polycythemia vera and essential thrombocythemia. Thirty-six patients were examined sequentially prior to and after start of hydroxy-urea therapy (8 polycythemia vera, 17 essential thrombocythemia), or while remaining untreated (2 polycythemia vera, 9 essential thrombocythemia). Hydroxyurea therapy (median duration: 15 months) reduced the %JAK2V617F by >30% in 13/25 patients (4 polycythemia vera, 9 essential thrombocythemia). For 3 patients, JAK2V617F remained undetectable for 3-27 months. In addition, a single time point study of two large cohorts of patients, examined either at the time of diagnosis (99 polycythemia vera, 178 essential thrombocythemia) or while receiving hydroxyurea (36 polycythemia vera, 98 essential thrombocythemia; median length of therapy: 32 months), confirmed reduction of %JAK2V617F in the hydroxyurea-treated group (24% vs. 33% JAK2V617F at diagnosis, p<0.01). Prospective studies are needed to determine the prognostic value of reduced JAK2V617F allele burden under cytoreductive therapy.
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http://dx.doi.org/10.3324/haematol.13081DOI Listing
November 2008