Browsing by Author "Beckett, Sophie"
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Item Open Access Accuracy of computed radiography in osteometry: a comparison of digital imaging techniques and the effect of magnification(Elsevier, 2019-10-24) Carew, Rachael M.; Viner, Mark D.; Conlogue, Gerald J.; Márquez-Grant, Nicholas; Beckett, SophieIntroduction Osteometric data may be obtained using digital imaging techniques, such as post-mortem computed tomography (PMCT) and digital radiography, non-invasively and without ethical objection. Osteometric data from PMCT is known to be as accurate as taking direct measurements. Digital radiography is more accessible and affordable than PMCT but is limited due to the magnification of its subjects. Objectives To investigate the viability of implementing digital radiographic techniques for measurement of long bones, and to establish whether magnification can be accurately corrected for. Materials and Methods Twenty hind pig (Sus scrofa) legs were imaged using computed radiography (CR) and PMCT, and osteometric data obtained from the digital images and 3D CT volume reconstructions. Direct measurements were taken following maceration. A calibration object was imaged using CR, to provide magnification correction factors. Results Accuracy was determined by mean absolute error (AE), giving values of 3.3 ± 2.5 mm for PMCT (MPR), 2.4 ± 1.3 mm for PMCT (3D), 11.1 ± 7.4 mm for CR (PA), and 18.3 ± 14.5 mm for CR (LAT). PMCT data was more accurate than CR data. Through applying correction for magnification, CR data became closer to the direct measurement data, and stature estimation was substantially altered. Conclusion Magnification in computed radiography affects osteometric data and resulting stature estimations. Applying correction factors may be a viable option for improving accuracy. For digital radiography to be used reliably in forensic anthropology, further empirical research is needed to validate a magnification correction method.Item Open Access The Anglo-Saxon migration and the formation of the Early English gene pool(Springer Nature, 2021-09-21) Gretzinger, Joscha; Sayer, Duncan; Justeau, Pierre; Beckett, SophieThe history of the British Isles and Ireland is characterized by multiple periods of major cultural change, including the influential transformation after the end of Roman rule, which precipitated shifts in language, settlement patterns and material culture1. The extent to which migration from continental Europe mediated these transitions is a matter of long-standing debate [2,3,4]. Here we study genome-wide ancient DNA from 460 medieval northwestern Europeans—including 278 individuals from England—alongside archaeological data, to infer contemporary population dynamics. We identify a substantial increase of continental northern European ancestry in early medieval England, which is closely related to the early medieval and present-day inhabitants of Germany and Denmark, implying large-scale substantial migration across the North Sea into Britain during the Early Middle Ages. As a result, the individuals who we analysed from eastern England derived up to 76% of their ancestry from the continental North Sea zone, albeit with substantial regional variation and heterogeneity within sites. We show that women with immigrant ancestry were more often furnished with grave goods than women with local ancestry, whereas men with weapons were as likely not to be of immigrant ancestry. A comparison with present-day Britain indicates that subsequent demographic events reduced the fraction of continental northern European ancestry while introducing further ancestry components into the English gene pool, including substantial southwestern European ancestry most closely related to that seen in Iron Age France [5,6].Item Open Access Contrasting the crystallinity indicators of heated and diagenetically altered bone mineral(Elsevier, 2010-10-01) Rogers, Keith; Beckett, Sophie; Kuhn, Samira; Chamberlain, Andrew; Clement, JohnModifications to bone mineral as a result of diagenesis or heating include a marked increase in crystallinity. Although these processes are not completely understood a number of simple, pragmatic approaches are in general use to quantify crystallinity and thus provide a relative metric for features such as preservation state. A preliminary investigation into the interpretation of crystallinity as measured by X-ray diffraction has been undertaken. The microstructural changes associated with diagenetically altered (archaeological) and heated contemporary bone have been examined. A common analysis approach was adopted and thus direct comparison between the physical features of these material systems has been possible. The data clearly demonstrate the pronounced anisotropic nature of the crystallite microstructure for both diagenetically altered and contemporary bone. The limitations of adopting simple crystallinity indices for characterising such materials are explored. Crystallite size and strain were shown to be dependent upon crystallographic direction. Overall, the diagenetically altered bone mineral possessed greater long range lattice order than that of contemporary heated bone. Further, significant differences between the directional nature of the microstructure of diagenetically altered and modern heated bone were observed. This study has enabled a direct comparison of the effects of heating and diagenesis upon bone mineral. It has demonstrated the need to consider bone microstructure anisotropically.Item Open Access Differentiating human versus non-human bone by exploring the nutrient foramen: implications for forensic anthropology(Springer, 2017-08-21) Johnson, V.; Beckett, Sophie; Marquez-Grant, NicholasOne of the roles of a forensic anthropologist is to assist medico-legal investigations in the identification of human skeletal remains. In some instances, only small fragments of bone may be present. In this study, a non-destructive novel technique is presented to distinguish between human and non-human long bones. This technique is based on the macroscopic and computed tomography (CT) analysis of nutrient foramina. The nutrient foramen of long bone diaphyses transmits the nutrient artery which provides much of the oxygen and nutrients to the bone. The nutrient foramen and its canal were analysed in six femora and humeri of human, sheep (Ovies aries) and pig (Sus scrofa) species. The location, position and direction of the nutrient foramina were measured macroscopically. The length of the canal, angle of the canal, circumference and area of the entrance of the foramen were measured from CT images. Macroscopic analysis revealed the femora nutrient foramina are more proximal, whereas humeri foramina are more distal. The human bones and sheep humerus conform to the perceived directionality, but the pig bones and sheep femur do not. Amongst the parameters measured in the CT analysis, the angle of the canal had a discriminatory power. This study shows the potential of this technique to be used independently or complementary to other methods in distinguishing between human and non-human bone in forensic anthropology.Item Open Access The effect of fabric mass per unit area and blood impact velocity on bloodstain morphology(Elsevier, 2019-05-09) Dicken, Anthony; Knock, Clare; Beckett, Sophie; Carr, Debra J.This paper discusses the effects of thickness, mass per unit area, sett, yarn linear density and twist of calico fabrics (100% cotton, plain woven) on the morphology of passive bloodstains. Horse blood was dropped vertically onto three calico fabrics with different mass per unit areas (85.1 g/m², 163.5 g/m² and 224.6 g/m²). Six different impact velocities were used (1.7 ms-1, 2.9 ms-1, 4.1 ms-1, 4.9 ms-1, 5.1 ms-1 and 5.4 ms-1). The dry bloodstains were largest on the calico with the lightest mass per unit area. The low yarn linear density and large inter-yarn spaces meant that the blood could wick into the yarns from all directions and along the intra-yarn spaces. The calico with the middle mass per unit area had the smallest mean dry bloodstain area for four out of the six velocities. The twist level for this calico was greater than for the calicos with a heavier or lighter mass per unit area. This reduced the amount of wicking which occurred along the yarns due to the tighter yarn structure. The calico with the heaviest mass per unit area had the highest yarn linear density resulting in a thicker fabric, so the blood could not as easily penetrate into the fabric. This resulted in a thicker wet blood layer remaining on the fabric surface, where it gradually wicked vertically into the yarns under gravity. Less wicking along the yarns occurred, resulting in a smaller bloodstain than on the fabric with the lightest mass per unit area. The correlation between impact velocity and mean dry bloodstain area was greater for the calicos with the medium and heaviest mass per unit area than for the calico with the lightest mass per unit area. For the calicos with the medium and heaviest mass per unit area, the distance the blood spread laterally at impact, which increased with the increase in impact velocity, had a greater influence on the dry bloodstain area than the amount of wicking.Item Open Access The effect of reactive dyeing of fabric on the morphology of passive bloodstains(Elsevier, 2022-04-30) Dicken, Lisa; Knock, Clare; Carr, Debra J.; Beckett, SophieThe majority of fabrics at crime scenes have been coloured in some way. The effect of such treatments on resultant bloodstains has not been considered. In this work, horse blood was dropped onto reactively dyed calico fabrics (100% cotton, plain woven) with three different masses of 91 g m-², 171 g m-² and 243 g m-² and the results compared to previous work on the not-coloured calico fabric. Five impact velocities were used from 1.7 ms−1 to 5.4 ms−1. The use of reactive dye increased the thickness (from 0.38 – 0.56 mm to 0.39 – 0.6 mm) and mass per unit area (from 85.1 – 224.6 g/m² to 91 – 243 g/m²) of the calico fabrics. The reactively dyed fabrics had larger bloodstains (e.g. lightest calico 41.2 – 78.6 mm²) compares to the not-coloured fabrics (e.g. lightest calico 21.4 – 67.5 mm²) across all three mass per unit areas. The dyeing of the fabrics altered the intra-yarn spaces to a more optimum size for wicking blood, increasing the ease with which the blood could wick along the yarns in the dyed calico. The amount of wicking varied depending on individual variations within the fabrics and yarns. More variation in dry bloodstain area was seen among dyed calico specimens than for the not-coloured fabric. The amount of wicking which was seen on the dyed calico meant there was no correlation between dry bloodstain area and impact velocity, a correlation which was seen on the medium and heavy not-coloured calico in the previous work.Item Open Access The effect of the digital printing of fabric on the morphology of passive bloodstains(Elsevier, 2022-11-10) Dicken, Lisa; Knock, Clare; Carr, Debra J.; Beckett, SophieBloodstained fabrics found at crime scenes are likely to have had processing treatments, such as dyeing or printing, but the effect of the treatments on bloodstain morphology is not always considered. In order to study the effect of digital printing on bloodstain morphology, drip stains were created from five impact velocities (1.9–5.4 ms−1) on three different mass per unit areas (88–226 g/m²) of 100% cotton calico which had been digitally printed using reactive dye. Across all three printed fabrics, the bloodstains appeared visually similar, and no correlation was found between the dry bloodstain area and the impact velocity. When comparing the bloodstains on the printed fabric to those which had been created previously on the same fabric in a dyed and not-coloured state, the dry bloodstains on the printed fabric were statistically significantly larger (e.g. for the calico with the lightest mass per unit area, mean dry bloodstain area was 126.6, 64.4 and 44.3 mm² for the printed, dyed and not-coloured fabrics respectively). Examination of the larger bloodstains on the printed calico with the micro computed tomography scanner and scanning electron microscope, suggested that the printing process increased the wettability of the fabric, so the blood could spread more easily on the surface. This allowed the blood to coat the yarns, and wick into them before wicking along the intra-yarn spaces. The results presented in this paper showed that care must be taken when examining bloodstains at crime scenes. Depending on the fabric and the processing of the fabric the size of the blood stains may not increase with impact velocity as wicking may result in a larger bloodstain from a lower velocity. The bloodstain on the penetrated face of the fabric may be larger than on the impacted face and the same fabrics with different processing will produce different blood stain sizes and shapes.Item Open Access Inter-species variation in bone mineral(2011-02-15) Beckett, Sophie; Rogers, Prof K.Bone is a complex heterogeneous composite material with organic and inorganic components. The inorganic component; bone mineral, is a poorly crystalline, non-stoichiometric form of calcium hydroxylapatite. A model for the general structure and composition of bone mineral has been established within the literature. However, the nature and extent of variation in bone mineral composition and structure has, to date, been poorly understood. This situation also applies to the general response of bone mineral to heat treatment and variation in this response. This thesis presents the results of an investigation of inter-species variation in bone mineral characteristics of unheated bone and bone heated to temperatures of 600 °C and 1400 °C. Twelve different animal species were investigated, including human bone. X-ray diffraction analysis was the primary analytical technique employed. The Rietveld method of full profile fitting of diffraction data was used to quantitatively investigate characteristics of unheated and heated bone such as the weight percentages of the thermal decomposition products of bone mineral. Infrared spectroscopy, inductively coupled plasma – atomic emission spectrometry, pyrohydrolysis – ion chromatography and combustion – gas chromatography were also employed to obtain further data regarding the chemical composition of bone. Biological ii control of bone mineral composition and structure and the chemical basis for the variation observed within the results were explored. Significant inter-species variation in bone mineral composition and structure and also, the response of bone to heat treatment have been demonstrated by the results of this thesis. In particular, human bone is significantly different from bone of all other species investigated.Item Open Access Investigating bloodstain dynamics at impact on the technical rear of fabric(Elsevier, 2019-05-19) Dicken, Lisa; Knock, Clare; Carr, Debra J.; Beckett, SophieUsing high speed video, the impact of blood drops falling at three velocities (1.9, 4.2 and 5.8 ms−1) were filmed from both the technical face and for the first time the technical rear of three different mass per unit areas (85.1, 163.5 and 224.6 g/m²) of 100% cotton calico. It was seen that there were two stages in the creation of a bloodstain on fabric; the impact dynamics, followed by wicking along the intra-yarn spaces. In the first stage, once the blood impacted the fabric, blood was visible on the technical rear of the fabrics with the medium and lightest mass per unit area within as little as 0.067 ms after impact. No blood was visible on the technical rear of the fabric with the heaviest mass per unit area following impact or the medium mass per unit area from 1.7 ms−1 impacts. On the technical face of the fabric, the blood drop spread laterally and then receded for 8 ms following impact. The dynamics on the technical face were not affected by what was occurring on the technical rear of the fabric. The bloodstain on the technical rear initially only increased until 0.8 ms following impact. The increase in technical rear bloodstain area was caused by continued movement of the blood through to the rear of the fabric as the blood drop spread on the technical face. Once the impact dynamics were concluded within 8 ms of impact, there was no further change in the bloodstain for the remaining 67 ms of high speed video. Following this the blood wicked into and along the yarns, resulting in a dry technical rear bloodstain on all fabrics at all velocities.Item Open Access The physical characterisation and composition of archaeological dental calculus(2017) Cooper, K. A.; Beckett, Sophie; Marquez-Grant, NicholasDental calculus is a complex biological material that has been found to provide significant evidence of past population diet, health and habitual activity. It is composed of mineral phases, trace elements, organic species and can have inclusions such as starch granules and microfossils incorporated into its structure. This composition has been found to vary among individuals, although the reasons for this are poorly understood. Despite this, there is a wealth of knowledge that can be gained from analysing this biomineral, especially from archaeological remains. In past populations, the variables that affect composition, such as pharmaceuticals and diet are reduced compared to modern populations. As such the reliance on clinical studies that have investigated dental calculus from modern individuals, may be flawed when considering past populations. The focus of this study was to provide insight about the variation in physical characterisation and composition of archaeological dental calculus. Despite there being an abundance of archaeological dental calculus research, this is the first large scale compositional study of specimens from three separate past populations. In addition, this research is the first study to adopt a non-destructive to destructive approach to archaeological dental calculus analysis. As well, it is the first application of nanocomputed tomography to dental calculus from past populations. Consequently, this study demonstrates the first evidence of accumulation layering that has been detected using non- estructive nano-computed tomography. Furthermore, this research has identified three types of layering in archaeological dental calculus. Due to these findings, it is expected that this research will impact the future of dental calculus analysis, especially when considering dental calculus as a method of mapping an individual’s health, diet or lifestyle in the weeks or months prior to death. The overall results of this thesis demonstrate that some aspects of the morphological, mineralogical and elemental analysis of archaeological dental calculus are inconsistent with clinical literature. The results have also shown that there are some differences between the dental calculus from different archaeological populations which can be related to post-mortem burial conditions.Item Open Access Physiochemical modifications to bone mineral(2016-10-05) Greenwood, Charlene; Rogers, Prof K.; Beckett, SophieBone is a complex composite material consisting of three main components: a mineral phase structurally similar to calcium hydroxyapatite (HAp), an organic matrix containing collagenous and non-collagenous proteins and, water. The complexity of bone has led to an abundance of literature across a wide range of disciplines, which have endeavoured to provide a greater understanding of this material. In particular, heated bone studies are prevalent in biomedicine where heat treatment is often used to sterilise bone material required for xeno– and allo- grafts, in forensic science where species differentiation of unknown heated bone specimens would prove invaluable and in archaeology, where heated bone material often provides information about the cooking and funeral practices of our ancestors. Unfortunately, many of these studies are largely observational and some of the processes and mechanisms associated with heated bone are largely assumed and in some instances ambiguous. Over 1000 biological and synthetic HAp specimens were utilised during this research to investigate the fundamental processes and mechanisms associated with unheated and heated bone. In particular, three controversial areas of bone research were considered: - in vivo HAp crystal size control, the relationship between the organic and mineral components of bone during heat treatment and the confounding effects of cooling on bone mineral during heat treatment. This was achieved by considering the chemical composition of unheated biological and synthetic HAp specimens, and heated bone specimens from various species including human. The results of this thesis demonstrate that an intrinsic rather than extrinsic source may be responsible for in vivo biological HAp crystal size control, a concept which has not previously be considered. The results have also shown bone mineral crystallisation during heat treatment is promoted by the organic matrix and, cooling has an impact on both crystallisation and thermal decomposition of HAp during heat treatment. This research has also questioned the use of current X-ray diffraction (XRD) refinement techniques with nanocrystalline materials such as bone, to determine crystalline size and strain. Further interpretation of the results questioned whether heated bone data is comparable between research groups, whether it was possible to create a time and temperature predictive model for heated bone and whether human bone is statistically different from other bone types when dynamically heated. Due to the fundamental nature of this research, it is expected the results will have an impact across a wide range of disciplines including biomedicine, forensic science and archaeology.Item Open Access The use of micro computed tomography to ascertain the morphology of bloodstains on fabric(Elsevier, 2015-10-23) Dicken, Lisa; Knock, Clare; Beckett, Sophie; de Castro, Therese C.; Nickson, Tania; Carr, Debra J.Very little is known about the interactions of blood and fabric and how bloodstains on fabric are formed. Whereas the blood stain size for non-absorbent surfaces depends on impact velocity, previous work has suggested that for fabrics the blood stain size is independent of impact velocity when the drop size is kept constant. Therefore, a greater understanding of the interaction of blood and fabric is required. This paper explores the possibility of using a micro computed tomography (CT) scanner to study bloodstain size and shape throughout fabrics. Two different fabrics were used: 100% cotton rib knit and 100% cotton bull drill. Bloodstains were created by dropping blood droplets from three heights; 500 mm, 1000 mm and 1500 mm. Results from the CT scanner clearly showed the bloodstain shape throughout the fabric. The blood was found to form a diamond shaped stain, with the maximum cross-sectional area 0.3–0.5 mm below the surface. The bloodstain morphology depended on both the impact velocity and fabric structure.