Considerations for Post-processing Parameters in Mixed-Method 3D Analyses: A Mesolithic Mandibular Case Study

The production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci. La producción de mallas digitales tridimensionales (3D) de superficie e información tomográfica computarizada (TC) se ha generalizado en los analisis morfométricos de datos antropológicos y arqueológicos. Dado que los métodos de procesamiento no están estandarizados quedan dudas sobre la comparabilidad de conjuntos de datos 3D procesados y curados digitalmente. El objetivo de este estudio fue identificar los parámetros de procesamiento que tienen la compatibilidad más consistente entre mallas derivadas de TC y un modelo de superficie 3D de la misma mandibula humana. Fueron comparadas ocho mallas cada una con parámetros únicos de umbralización y suavizado, para evaluar las desviaciones de todo el objeto, las desviaciones a lo largo de las curvas y las desviaciones entre características anatómicas específicas en el modelo de superficie, en comparación con cada una de las tomografías computarizadas utilizando un conjunto de puntos de comparación. Con base en las distancias de separación calculadas, aunque no las más precisas desde el punto de vista biológico, se encontró que la malla con umbral en “0” con una técnica de suavizado aplicada se desvía menos de la superficie modelo. Los resultados tienen implicaciones para los estudios agregados que emplean conjuntos de datos 3D multimodales y se recomienda precaución para los estudios que incluyen datos 3D de sitios web y repositorios digitales, especialmente si los parámetros de procesamiento son desconocidos o derivados de estudios con diferentes focos de investigación

Bone growth and development in prehistoric populations from Sudanese Nubia,

The analysis of a large sample of skeletons from a number of Sudanese Nubian cemeteries demonstrates the usefulness of this material in the study of bone growth and development. A skeletal series from the Meroitic (B.C. 350-A.D. 350), X-Group (A.D. 350-550), and Christian (A.D. 550-1400) period were utilized in determining the rate of bone development and age related changes in the internal structure of the femur. Specifically, we have been able to demonstrate the following: 1. (i) The growth velocity determined from the long bones in the Nubian sample was similar but somewhat more irregular than the growth velocity of long bones in American boys studied longitudinally.2. (2) Growth symmetry of long bones determined by the ratio of lengths shows a greater stability than that which occurs in American boys.3. (3) Decrease in femoral cortical thickness with age was significant in Nubian females (P 4. (4) The density of femoral head trabecular bone organ volume decreases with age at similar rates in both males and females, but the females lose a larger percentage of density since they enter the age period (17 years) with a lower density.5. (5) The average thickness of femoral head trabeculae decrease with age in males, while in females there is an increase in thickness. It appears that as cross-members decrease in thickness with age, struts increase in thickness.6. (6) Microradiographic analysis of archeological material may provide an additional dimension to the study of bone turnover rates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34191/1/0000480.pd

Social stratification without genetic differentiation at the site of Kulubnarti in Christian Period Nubia

Relatively little is known about Nubia’s genetic landscape prior to the influence of the Islamic migrations that began in the late 1st millennium CE. Here, we increase the number of ancient individuals with genome-level data from the Nile Valley from three to 69, reporting data for 66 individuals from two cemeteries at the Christian Period (~650–1000 CE) site of Kulubnarti, where multiple lines of evidence suggest social stratification. The Kulubnarti Nubians had ~43% Nilotic-related ancestry (individual variation between ~36–54%) with the remaining ancestry consistent with being introduced through Egypt and ultimately deriving from an ancestry pool like that found in the Bronze and Iron Age Levant. The Kulubnarti gene pool – shaped over a millennium – harbors disproportionately female-associated West Eurasian-related ancestry. Genetic similarity among individuals from the two cemeteries supports a hypothesis of social division without genetic distinction. Seven pairs of inter-cemetery relatives suggest fluidity between cemetery groups. Present-day Nubians are not directly descended from the Kulubnarti Nubians, attesting to additional genetic input since the Christian Period.K.A.S. was supported by a Doctoral Dissertation Research Improvement Grant from the National Science Foundation (BCS-1613577). D.R. was funded by NSF HOMINID grant BCS-1032255; NIH (NIGMS) grant GM100233; the Allen Discovery Center program, a Paul G. Allen Frontiers Group advised program of the Paul G. Allen Family Foundation; the John Templeton Foundation grant 61220; and the Howard Hughes Medical Institute

Exploring, exploiting and evolving diversity of aquatic ecosystem models: A community perspective

Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of existing models. Finally, we discuss how model diversity came about in the past and could evolve in the future. Throughout our study, we use analogies from biodiversity research to analyse and interpret model diversity. We recommend to make models publicly available through open-source policies, to standardize documentation and technical implementation of models, and to compare models through ensemble modelling and interdisciplinary approaches. We end with our perspective on how the field of aquatic ecosystem modelling might develop in the next 5–10 years. To strive for clarity and to improve readability for non-modellers, we include a glossary

Development and implementation of clinical guidelines : an artificial intelligence perspective

Clinical practice guidelines in paper format are still the preferred form of delivery of medical knowledge and recommendations to healthcare professionals. Their current support and development process have well identified limitations to which the healthcare community has been continuously searching solutions. Artificial intelligence may create the conditions and provide the tools to address many, if not all, of these limitations.. This paper presents a comprehensive and up to date review of computer-interpretable guideline approaches, namely Arden Syntax, GLIF, PROforma, Asbru, GLARE and SAGE. It also provides an assessment of how well these approaches respond to the challenges posed by paper-based guidelines and addresses topics of Artificial intelligence that could provide a solution to the shortcomings of clinical guidelines. Among the topics addressed by this paper are expert systems, case-based reasoning, medical ontologies and reasoning under uncertainty, with a special focus on methodologies for assessing quality of information when managing incomplete information. Finally, an analysis is made of the fundamental requirements of a guideline model and the importance that standard terminologies and models for clinical data have in the semantic and syntactic interoperability between a guideline execution engine and the software tools used in clinical settings. It is also proposed a line of research that includes the development of an ontology for clinical practice guidelines and a decision model for a guideline-based expert system that manages non-compliance with clinical guidelines and uncertainty.This work is funded by national funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project PEst-OE/EEI/UI0752/2011"

Tetracycline-Labeled Human Bone From A Medieval Population In Nubia’s Batn El Hajar (550-1450 A.D.)

Tetracycline-labeling of bone is a phenomenon well established in the literature and recently has been discovered in archaeological human bone of some antiquity. This is the second reported finding of tetracycline-labeled human bone from Sudanese Nubia. This study examines the biocultural implications of the tetracycline and its possible relationship to the incidence of disease and overall patterns of health in a population from Nubia’s Batn el Hajar. Analysis of the bone for the presence of both tetracycline and infectious lesions showed low levels of the former and moderate levels of the later, but no statistical relationships between the two. The present data suggest that the occasional ingestion of low concentrations of tetracycline had no positive impact on disease in this population

Elemental Hair Analysis: New Evidence on the Etiology of Cribra Orbitalia in Sudanese Nubia

One hundred sixty eight hair samples recovered from two Christian era Nubian cemeteries (550-1450) were subjected to analysis of major and trace elements. Concentrations of magnesium, calcium, strontium, iron, zinc, copper and manganese were determined using inductively coupled plasma spectrometry. Mean levels of each element determined from the Nubian hair compare closely to those documented for modern samples and likely reflect a number of important environmental and biological factors affecting the population. Specifically, the present results provide a quantitative method for assessing the nutritional and disease factors contributing to cribra orbitalia (porotic hyperostosis), a frequent pathology in Nubian remains attributed to iron deficiency anemia. A comparison of iron levels between infants and children with and without cribra orbitalia demonstrates a significantly lower iron level for the affected group. In addition, concentrations of magnesium are also significantly lower for the Nubian subadults with cribra orbitalia. This new finding is consistent with clinical observations in which anemia has been produced in magnesium deficient animals, including humans. A reduction in magnesium lends further support to the hypothesis that age-specific stress stemming from weaning practices, parasitic infection and inadequate diet contributed to cribra orbitalia and its associated anemia in ancient Nubia

Patterns of Age-Related Cortical Bone Loss (Osteoporosis) Within the Femoral Diaphysis

The rate and degree of cortical bone loss was examined at five sites along the femoral diaphysis in males and females aged 20 through 55+ from an archeologically excavated Amerindian population. Age-related remodeling within the diaphysis was evaluated using measures of cortical thickness, cross-sectional area, and diaphyseal diameter. The results tend to confirm previous studies indicating: 1. a high degree of association between endosteal bone loss and the aging process after the third decade of life; 2. that osteoporotic hone loss is both relatively and absolutely greater among females than among males, and; 3. that bone growth at the sub-periosteal surface continues through the decades studied in both sexes. This study found further that: 1. differential rates of cortical bone loss and associated remodeling are found within the femoral diaphysis, and; 2. these remodeling differences appear to be sex-specific. The reduction in cortical thickness and cross-sectional area was most apparent in the proximal one-third of the femoral diaphysis among the females, and in the distal one-third of the femoral diaphysis among the males. Cortical bone loss tended to be offset to varying degrees in both sexes by apposition at the sub-periosteal surface, which appeared to act as a compensatory factor bringing about an increase in diameter in those areas of the diaphysis where the greatest amount of endosteal resorption occurred