Luminol and the postmortem interval estimation - influence of taphonomic factors.

The estimation of the postmortem interval (PMI) is one of the key challenges for forensic anthropologists. Although there are several methods referenced for this purpose, none is sufficiently effective. One of the main reasons justifying the complexity of this task is the influence of several taphonomic factors.The study of the Luminol technique has stood out as a promising method for estimating PMI, complementing the existing methods, since it is an economic, easy and reproducible method that operates as a presumptive test. However, it is not known which taphonomic factors can influence the results obtained by this technique.The aim of this study is to test the influence of taphonomic factors, such as temperature, humidity, soil type and pH, on the estimation of the PMI by the Luminol technique.In order to test the influence of the referred factors, a sample consisting of 30 clavicles, with known and similar PMI, collected from autopsies, was distributed as evenly as possible by six vases and buried with different decomposition conditions for a period of 12 months. After the exhumation and sample preparation, the Luminol technique was applied.It was possible to clearly observe differences in the results. Thus, according to our research, it is possible to conclude that the results obtained by the application of Luminol are influenced by taphonomic factors. Therefore, the context in which a body is found should always be considered for applying this technique.

All that glitters is not gold: X-ray fluorescence analysis of a fixed dental prosthesis from Colecção de Esqueletos Identificados Século XXI, Portugal (CEI/XXI).

Access to better health care anticipates that more medical devices can be found alongside skeletal remains. Those employed in oral rehabilitation, with available brands or batch/series, can prove useful in the identification process. A previous study in the Colecção de Esqueletos Identificados Século XXI described macroscopically the dental prostheses. An unusual case of a dental device with chromatic alterations demonstrated to require a more detailed analysis. The individual, a 53-year-old male, exhibited, at both arches, a fixed tooth-supported rehabilitation, with gold colouring classified initially as a gold-palladium alloy. Simultaneously, a green pigmentation deposit was observable in bone and prosthesis. This investigation aimed to verify the elemental composition of the dental prosthesis alloy. Elemental analysis was performed by X-ray fluorescence in two regions (labial surface of the prosthetic crown and the root surface of the lower right lateral incisor). Both the spectra and the qualitative results found higher levels of copper and aluminium, followed by nickel, iron, zinc, and manganese. No gold or palladium was detected. The most probable assumption is that a copper-aluminium alloy was used, as its elemental concentration corresponds to those measured in similar devices. Dental prostheses of copper-aluminium alloys have been made popular since the 1980s, particularly in the USA, Japan, and Eastern Europe. Apart from the biographical information, it was also known that the individual's place of birth was an Eastern European country, which highlighted the usefulness of this type of information when dealing with missing people cases.

Age assessment in unaccompanied minors: assessing uniformity of protocols across Europe.

Age assessment of migrants is crucial, particularly for unaccompanied foreign minors, a population facing legal, social, and humanitarian challenges. Despite existing guidelines, there is no unified protocol in Europe for age assessment.The Forensic Anthropology Society of Europe (FASE) conducted a comprehensive questionnaire to understand age estimation practices in Europe. The questionnaire had sections focusing on the professional background of respondents, annual assessment numbers, requesting parties and reasons, types of examinations conducted (e.g., physical, radiological), followed protocols, age estimation methods, and questions on how age estimates are reported.The questionnaire's findings reveal extensive engagement of the forensic community in age assessment in the living, emphasizing multidisciplinary approaches. However, there seems to be an incomplete appreciation of AGFAD guidelines. Commonalities exist in examination methodologies and imaging tests. However, discrepancies emerged among respondents regarding sexual maturity assessment and reporting assessment results. Given the increasing importance of age assessment, especially for migrant child protection, the study stresses the need for a unified protocol across European countries. This can only be achieved if EU Member States wholeheartedly embrace the fundamental principles outlined in EU Directives and conduct medical age assessments aligned with recognized standards such as the AGFAD guidelines.

Validation of discriminant functions from the rib necks in two Portuguese adult identified populations.

Sexual dimorphism is the basis for sex estimation research in skeletal remains, helping the positive identification of individuals in forensic backgrounds. In this regard, it has been proved that the metrical analysis of the costal neck of the first four ribs in Spanish contemporary adult skeletons shows high sexual dimorphism, especially in the first rib. However, the validation of any method developed in identified skeletal collections must be compulsorily reproduced in other skeletonized sets to verify either its potential application in individuals from other locations, or the existence of possible biases associated with inter-population variation. Due to the geographical and socioeconomic proximity between Spain and Portugal, this paper aims to check the utility of the discriminant functions designed by Partido-Navadijo et al. (2021) in the two skeletal collections of the University of Coimbra (Portugal). Results show the utility of these discriminant functions in Portuguese population, with frequencies of cases correctly assigned reaching up to 93.6% in the Coimbra Identified Skeletal Collection (CISC); and up to 92.6% in the 21st Century Identified Skeletal Collection (CEI/XXI). However, two particularities between the Spanish and Portuguese osteological assemblages can be highlighted: the possible existence of secular changes in relation to the CISC collection (1904-1938); and a reversal in the degree of costal dimorphism, being the third and fourth ribs of the CEI/XXI collection more dimorphic than the first ones.

Estimation of the post-mortem interval in human bones by infrared spectroscopy.

In forensic anthropology, there is an inherent difficulty in estimating the post-mortem interval (PMI). This study aimed to assess whether there is a correlation between changes in the bone mineral component and the PMI estimation. Samples of femur and humerus from 80 identified individuals with known post-mortem interval were analyzed. Infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) was applied for this analysis, several indices having been obtained from the infrared bands most representative of the bone's relative contents in carbonate and phosphate. Specific relationships between sex/age and PMI were attained: for larger PMIs, there was an increase in the amount of B-type carbonate (BPI), A-type carbonates (API), and in the carbonate/phosphate (C/P) ratio, and a decrease of the crystallinity index (CI) and in the carbonate ratio (C/C). Two particular infrared indices (CI and C/C) were identified as the most suitable for post-mortem interval estimation, especially in females, controlling the effects of sex and age (in the statistical analysis).

The dental prosthesis (removable and fixed) from the Colecção de Esqueletos Identificados Século XXI (CEI/XXI).

For identification of the unknown, the analysis of individualizing characteristics is a paramount procedure, which allows the reconciliation of antemortem with postmortem data. Worldwide, populations are commonly affected by tooth loss, leading to procedures of oral rehabilitation, such as dental prostheses. Although the potential of these devices for human identification is well known, the lack of marks or serial numbers as well as scarce systematic register on databases may difficult its use. The objective of this paper is to present and describe the cases with dentures and bridges of an identified osteological collection, the Colecção de Esqueletos Identificados Século XXI. All the individuals were macroscopically observed, and the cases presenting dental prostheses were registered. A total of thirty-one individuals (20 females; 11 males), ages 38 to 91 years, presented 49 dental prosthesis (removable or fixed), of various materials. The removable acrylic dentures (n = 42) were the most frequent. No identifying marks or production labels were found. This research reinforces two focal points: the value of studying and recognizing medical devices and their application for identification, and the relevance of identified skeletal collections for the advance of forensic science in the current multidisciplinary approach.

New data about the 21st Century Identified Skeletal Collection (University of Coimbra, Portugal).

After the publication of the first article in 2014, 21st Century Identified Skeletal Collection, housed in the Laboratory of Forensic Anthropology, Department of Life Sciences at the University of Coimbra, Portugal, has been growing. Currently, the collection is composed of 302 complete adult skeletons of both sexes, which means that in 5 years it has doubled. The collection consists mostly of elderly individuals, with only 12.25% of the individuals aged less than 61 years old. All individuals are Portuguese nationals who died between 1982 and 2012. Ninety individuals exhibit prostheses, other medical devices and signs of surgical procedures. Moreover, a sub-collection of experimentally burned skeletons is under development, and currently includes 56 individuals (18.54% of the collection). The 21st Century Identified Skeletal Collection constitutes a fundamental tool for forensic anthropology research, including the development and validation studies of methods that focus on elderly individuals, as can be ascertained by the numerous scientific publications and academic scholarship that have been produced in previous years.

The association of osteochemometrics and bone mineral density in humans.

OBJECTIVES: Even though much is known about bone mineral and matrix composition, studies about their relationship with several bone properties and its alterations related to bone diseases such as osteoporosis are practically non-existent in humans. Thus, the development of methods to understand the effects of bone properties at a microscopic level is paramount. This research aimed to evaluate whether Fourier transform infrared-attenuated total reflectance (FTIR-ATR) band intensity ratios correlate with femoral bone mass, bone mineral content (BMC) (total and femoral neck), bone mineral per unit area (BMD) (total, femoral neck, greater trochanter, intertrochanteric region, and Ward's area) and the area (total and femoral neck). A sample of femora from the 21st Century Identified Skeleton Collection (N = 78, 42 females and 36 males) was employed and BMC, BMD, and the femoral areas were acquired by DXA. RESULTS: It was found that only females' BMD had a significant association with the femoral FTIR-ATR indices under study, whereas bone collagen (Am/P) and the content of carbonate Type A (API) in males correlated with the total proximal femur area of the regions of interest and the femoral neck area. DISCUSSION: Men and women showed different changes related to their chemical composition in BMD, BMC, and probed area, most likely due to differences in structure and physiology, as well as mechanical strength in the proximal femoral sites where BMD was analyzed.

Beyond metrics and morphology: the potential of FTIR-ATR and chemometrics to estimate age-at-death in human bone.

In forensic anthropology, the application of traditional methods for estimating the biological profile of human skeletal remains is often hampered by poor preservation and skeletal representativeness, compromising their reliability. Thus, the development of alternative methods to the morphometric analysis of bones to estimate the biological profile of human remains is paramount. The age of an individual can cause changes in bone morphology, mass and size, as well as in its chemical composition. In this sense, the main objective of this research was to evaluate if the contents of bone collagen (Am/P), carbonate type A (API), carbonate type B (BPI), the relation between the carbonate content (types A and B) to type B carbonate (C/C), carbonate-phosphate ratio (C/P) and crystallinity index (CI), spectroscopic indices obtained from relationships between infrared absorption band intensities (FTIR-ATR), can be used as age-at-death predictors. A sample of femora and humeri from the 21st Century Identified Skeleton Collection (N = 80, 44 females and 36 males) was employed. Results show that, with advancing age, women's femora have lower CI values, but BPI and C/P indices increase, and the deformation and disorder of the crystal lattice are probably affected by the integration of type B carbonate content of the femur. The ratios analysed, especially the CI and the BPI, show potential to estimate age-at-death in human skeletal remains, when sex is already known, thus helping to assess the biological profile when conventional methods cannot be applied.

Preliminary results of an investigation on postmortem variations in human skeletal mass of buried bones.

Extreme fragmentation can complicate the inventory of human skeletal remains. In such cases, skeletal mass can provide information regarding skeleton completeness and the minimum number of individuals. For that purpose, several references for skeletal mass can be used to establish comparisons and draw inferences regarding those parameters. However, little is known about the feasibility of establishing comparisons between inherently different materials, as is the case of curated reference skeletal collections and human remains recovered from forensic and archaeological settings. The objective of this paper was to investigate the effect of inhumation, weather and heat exposure on the skeletal mass of two different bone types. This was investigated on a sample of 30 human bone fragments (14 trabecular bones and 16 compact bones) that was experimentally buried for two years after being submitted to one of four different heat treatments (left unburned; 500 °C; 900 °C; 1000 °C). Bones were exhumed periodically to assess time-related mass variation. Skeletal mass varied substantially, decreasing and increasing in accordance to the interchanging dry and wet seasons. However, trends were not the same for the two bone types and the four temperature thresholds. The reason for this appears to be related to water absorption and to the differential heat-induced changes in bone microporosity, volume, and composition. Our results suggest that mass comparisons against published references should be performed only after the skeletal remains have been preemptively dried from exogenous water.

A test and analysis of Calce (2012) method for skeletal age-at-death estimation using the acetabulum in a modern skeletal sample.

In forensic anthropology, the age-at-death of an adult individual is one of the most complex parameters of the biological profile to estimate. The present study aims to evaluate the reliability of the Calce (2012) method for the estimation of age-at-death through acetabulum changes in a sample of Portuguese origin. This method consists of the global analysis of acetabular age-related morphology with focus on three specific traits, namely the acetabular groove, the osteophyte development of the acetabular rim, and the apex growth. This method was tested in 120 individuals sampled from the Twenty-first Century Identified Skeletal Collection (University of Coimbra, Portugal). The test sample is composed of 60 males and 60 females, aged between 25 and 99 years, with well-preserved os coxae. The results showed that only 60% of the individuals were correctly attributed to the age group defined by the technique. The comparison with previous studies in other populations shows significant inter-population differences in the relationship between the acetabulum variables used by Calce and age-at-death. The obtained results advise caution in the use of the Calce (2012) method to estimate the age-at-death of unidentified skeletons.

Eco-geographic adaptations in the human ribcage throughout a 3D geometric morphometric approach.

OBJECTIVES: According to eco-geographic rules, humans from high latitude areas present larger and wider trunks than their low-latitude areas counterparts. This issue has been traditionally addressed on the pelvis but information on the thorax is largely lacking. We test whether ribcages are larger in individuals inhabiting high latitudes than in those from low latitudes and explored the correlation of rib size with latitude. We also test whether a common morphological pattern is exhibited in the thorax of different cold-adapted populations, contributing to their hypothetical widening of the trunk. MATERIALS AND METHODS: We used 3D geometric morphometrics to quantify rib morphology of three hypothetically cold-adapted populations, viz. Greenland (11 individuals), Alaskan Inuit (8 individuals) and people from Tierra del Fuego (8 individuals), in a comparative framework with European (Spain, Portugal and Austria; 24 individuals) and African populations (South African and sub-Saharan African; 20 individuals). RESULTS: Populations inhabiting high latitudes present longer ribs than individuals inhabiting areas closer to the equator, but a correlation (p < 0.05) between costal size and latitude is only found in ribs 7-11. Regarding shape, the only cold adapted population that was different from the non-cold-adapted populations were the Greenland Inuit, who presented ribs with less curvature and torsion. CONCLUSIONS: Size results from the lower ribcage are consistent with the hypothesis of larger trunks in cold-adapted populations. The fact that only Greenland Inuit present a differential morphological pattern, linked to a widening of their ribcage, could be caused by differences in latitude. However, other factors such as genetic drift or specific cultural adaptations cannot be excluded and should be tested in future studies.

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. © 2016 Wiley Periodicals, Inc.

AncesTrees: ancestry estimation with randomized decision trees.

In forensic anthropology, ancestry estimation is essential in establishing the individual biological profile. The aim of this study is to present a new program--AncesTrees--developed for assessing ancestry based on metric analysis. AncesTrees relies on a machine learning ensemble algorithm, random forest, to classify the human skull. In the ensemble learning paradigm, several models are generated and co-jointly used to arrive at the final decision. The random forest algorithm creates ensembles of decision trees classifiers, a non-linear and non-parametric classification technique. The database used in AncesTrees is composed by 23 craniometric variables from 1,734 individuals, representative of six major ancestral groups and selected from the Howells' craniometric series. The program was tested in 128 adult crania from the following collections: the African slaves' skeletal collection of Valle da Gafaria; the Medical School Skull Collection and the Identified Skeletal Collection of 21st Century, both curated at the University of Coimbra. The first step of the test analysis was to perform ancestry estimation including all the ancestral groups of the database. The second stage of our test analysis was to conduct ancestry estimation including only the European and the African ancestral groups. In the first test analysis, 75% of the individuals of African ancestry and 79.2% of the individuals of European ancestry were correctly identified. The model involving only African and European ancestral groups had a better performance: 93.8% of all individuals were correctly classified. The obtained results show that AncesTrees can be a valuable tool in forensic anthropology.

An Activity-Based Probe for Studying Crosslinking in Live Bacteria.

Penicillin-binding proteins (PBPs) catalyze the crosslinking of peptidoglycan (PG), an essential process for bacterial growth and survival, and a common antibiotic target. Yet, despite its importance, little is known about the spatiotemporal aspects of crosslinking­largely because of a lack of experimental tools for studying the reaction in live bacteria. Here we introduce such a tool: an activity-based probe that enables visualization and relative quantitation of crosslinking in vivo. In Staphylococcus aureus, we show that fluorescent mimics of the natural substrate of PBPs (PG stem peptide) are covalently incorporated into the cell wall, installing fluorophores in place of natural crosslinks. These fluorescent stem peptide mimics (FSPMs) are selectively recognized by a single PBP in S. aureus: PBP4. Thus, we were able to use FSPM pulse-labeling to localize PBP4 activity in live cells, showing that it is recruited to the septum in a manner dependent on wall teichoic acid.

Dental disease in a 15th-17th centuries skeletal sample of enslaved Africans (Lagos, Portugal).

OBJECTIVE: Dental disease is frequently used as a proxy for diet and overall health of individuals of past populations. The aim of this study is to investigate dental disease in a sample of enslaved African individuals recovered from an urban dump (15th-17th centuries) in Lagos, Portugal. DESIGN: In all, 81 African individuals (>12 years old) were analysed (19 males, 49 females, and 13 of unknown sex), in a total of 2283 alveoli, 2061 teeth, and 2213 interdental septa. Analysed oral pathologies include dental caries, periodontal disease, and ante-mortem tooth loss. Dental wear was also recorded. RESULTS: Dental caries affected 52.0 % of the teeth, although only 31.9 % were cavitated lesions. In all, 96.3 % of the individuals presented at least one cariogenic lesion. Gingivitis and periodontitis were recorded in 56.7 % and 19.0 % of the septa, respectively. Only one male individual had all septal areas healthy. Ante-mortem tooth loss was recorded in 38.3 % of the individuals, in a total of 96 teeth lost (4.2 %). Regarding occlusal wear, 70.8 % of the surfaces were recorded with grades 1-3. CONCLUSIONS: The frequencies of the oral pathological conditions observed may not only reflect a cariogenic diet (rich in starches and with a high frequency of meals) but also the conditions during the maritime voyage of the first victims of the North Atlantic slave trade (xerostomia due to lack of water, sea sickness and vomiting, vitamin C deficiency, poor hygiene), and also the impact intentional dental modifications had on the dentitions.

The effects of exogenous substances on the color of heated bones.

OBJECTIVES: Burned bone coloration has been used for decades to help in the bioanthropological analysis of burned human bones. However, there is a variety of factors that can interfere with the coloration manifested by bones exposed to heat, resulting in colors that differ from the usual black to white gradient. In this study, we evaluated possible causes of unusual coloration changes and hues in burned bone. MATERIALS AND METHODS: For that purpose, defleshed fresh pig (Sus scrofa) ribs as well as fresh and dry human clavicles were burned at four different temperatures (500, 700, 900 and 1100°C) in contact with different materials (CaO, Zn, Fe, Cu, Mn, and polyester cloth). Observable color changes were assessed through naked eye observation and description, Munsell color charts, and reflectance spectrophotometry. Additionally, chemical changes in bone were assessed using Fourier-transform infrared spectroscopy in attenuated total reflectance (FTIR-ATR) and x-ray fluorescence (XRF). RESULTS: Our results showed that some materials did affect usual burned bone coloration (Fe, Mn, Cu, Zn) and correspondent FTIR-ATR and XRF spectra. As for other materials, although no effect on visual bone coloration was observed, they still affected FTIR-ATR and XRF spectra (CaO and cloth). DISCUSSION: This study can contribute to the anthropological analysis of burned human remains, providing some answers to what can cause unusual types of heat-induced colorations.

XRF identification of sharp-force trauma in fresh and dry human bone under varied experimental heat conditions.

Heat-induced fractures can be hard to distinguish from sharp force traumas. This challenge can negatively impact medico-legal analysis. The present study aimed to experimentally assess if X-ray fluorescence (XRF) can be used to detect chemical traces transferred from the blade of a sharp instrument onto both fresh and dry human bones. This was performed by inducing sharp force traumas with five different instruments on 20 fresh and 20 dry human clavicles. All bone samples were probed before and after experimental burning (at 500 °C, 700 °C, 900 °C and 1100 °C). Our results show that XRF is potentially useful for detecting iron traces in fresh human bone, both unburned and burned. However, we were not able to clearly detect iron traces from the blades in bones that have been previously inhumed, since exogenous iron acquired during diagenesis masks the iron traces originating from the blade.

The BALA project: A pioneering monitoring of Azorean forest invertebrates over two decades (1999-2022).

Globally, there is a concerning decline in many insect populations, and this trend likely extends to all arthropods, potentially impacting unique island biota. Native non-endemic and endemic species on islands are under threat due to habitat destruction, with the introduction of exotic, and potentially invasive, species, further contributing to this decline. While long-term studies of plants and vertebrate fauna are available, long-term arthropod datasets are limited, hindering comparisons with better-studied taxa. The Biodiversity of Arthropods of the Laurisilva of the Azores (BALA) project has allowed gathering comprehensive data since 1997 in the Azorean Islands (Portugal), using standardised sampling methods across islands. The dataset includes arthropod counts from epigean (pitfall traps) and canopy-dwelling (beating samples) communities, enriched with species information, biogeographic origins, and IUCN categories. Metadata associated with the sample protocol and events, like sample identifier, archive number, sampled tree species, and trap type are also recorded. The database is available in multiple formats, including Darwin Core, which facilitates the ecological analysis of pressing environmental concerns, such as arthropod population declines and biological invasions.

Secular Trends in the Size and Shape of the Scapula among the Portuguese between the 19th and the 21st Centuries.

Potential secular changes in the human scapula are fundamentally unbeknownst, with most of the preceding anatomical studies focusing on long-term changes in the long bones and the skull. As such, the cardinal purpose of this study pertains to the evaluation of secular trends on the shape and size of the scapula in a time period spanning from the 19th to the early 21st centuries. The study sample included 211 individuals (100 males and 111 females) from the Coimbra Identified Skeletal Collection and the 21st Century Identified Skeletal Collection. The size and shape of the scapula were evaluated using geometric morphometrics. Results show secular changes over a relatively short period of time in both the shape and size of the scapula in Portuguese nationals. Shape changes were observed in both sexes but expressed minimally, while a significant negative trend in the size of the scapula was detected in males. Scapular size decrement in males conceivably echoes general trends of the overall anatomy towards a narrower body associated with higher standards of living that include enhanced nutrition and universal healthcare, among other factors.