Concept: Osteometric points
Bones, teeth and hair are often the only physical evidence of human or animal presence at an archaeological site; they are also the most widely used sources of samples for ancient DNA (aDNA) analysis. Unfortunately, the DNA extracted from ancient samples, already scarce and highly degraded, is widely susceptible to exogenous contaminations that can affect the reliability of aDNA studies. We evaluated the molecular effects of sample handling on five human skeletons freshly excavated from a cemetery dated between the 11 to the 14(th) century. We collected specimens from several skeletal areas (teeth, ribs, femurs and ulnas) from each individual burial. We then divided the samples into two different sets: one labeled as “virgin samples” (i.e. samples that were taken by archaeologists under contamination-controlled conditions and then immediately sent to the laboratory for genetic analyses), and the second called “lab samples”(i.e. samples that were handled without any particular precautions and subject to normal washing, handling and measuring procedures in the osteological lab). Our results show that genetic profiles from “lab samples” are incomplete or ambiguous in the different skeletal areas while a different outcome is observed in the “virgin samples” set. Generally, all specimens from different skeletal areas in the exception of teeth present incongruent results between “lab” and “virgin” samples. Therefore teeth are less prone to contamination than the other skeletal areas we analyzed and may be considered a material of choice for classical aDNA studies. In addition, we showed that bones can also be a good candidate for human aDNA analysis if they come directly from the excavation site and are accompanied by a clear taphonomic history.
- Journal of controlled release : official journal of the Controlled Release Society
- Published almost 2 years ago
The development of stimuli-responsive nanomedicines with tunable cargo release is gathering an increased applicability in bone regeneration and precision biomedicine. Yet, the formulation of nanocarriers that explore skeletal-specific stimuli remains remarkably challenging to materialize due to several endogenous and disease-specific barriers that must be considered during particle design stages. Such anatomo-physiological constrains ultimately hinder nanocarriers bioavailability in target bone tissues and impact the overall therapeutic outcome. This review aims to showcase and critically discuss the hurdles encountered upon responsive nanocarriers delivery in the context of skeletal diseases or tissue regeneration scenarios. Such focus is complemented with an in-depth and up-to-date analysis of advances in the development of stimuli-responsive, bone-focused delivery systems. In a holistic perspective, a deeper knowledge of human osteology combined with advances in materials functionalization via simple precision-chemistry is envisioned to incite the manufacture of stimuli-triggered nanomedicines with more realistic potential for clinical translation.
Recording the preservation of human skeletal remains is the foundation of osteological analyses for forensic and archaeological skeletal material. Methods for recording the skeletal completeness, one of the components of skeletal preservation documentation, are however currently non-standardised and subjective. To provide practitioners with a scientific means to accurately quantify skeletal completeness in an adult skeleton, percentage values for each skeletal element have been established. Using computed tomography (CT) volume rendering applications and post-mortem CT skeletal data for one adult individual, the percentage value for each bone relative to the complete skeleton was calculated based on volume. Percentage values for skeletal elements ranged from 0.01% (select hand and foot bones) to 8.43% (femur). Visual and written mediums detailing individual skeletal percentages have been provided as user-friendly reference sources. Calculating the percentage of skeletal remains available for analysis provides practitioners with a means to scientifically and objectively record skeletal completeness.
Calyptocephalella gayi is one of over 6,000 neobatrachians arranged into two main groups, Hyloides and Ranoides. Phylogenetically, C. gayi is placed in Australobatrachia, a Gondwanan clade that is either the most basal clade of Hyloides or the sister group of Hyloidea, depending on the cladistic hypothesis; as such, this species is a key taxon in the study of the early evolution of Neobatrachia. The ontogeny of the postcranial skeleton of C. gayi is described in this article. The description is based on pattern of chondrification and ossification of skeletal elements in a growth series of tadpoles, on juveniles and adult individuals. Particular attention was devoted to some developmental aspects and morphological traits of the adult skeleton. The body of Presacral Vertebra VIII is formed from three centers of ossification, in contrast to the usual two dorsolateral centers observed in the remaining vertebrae of C. gayi, as well as in most anuran taxa for which the development of the axial skeleton is known. Each half of the pelvic girdle arises from a single cartilaginous element. The early development of the autopodia of both the forelimb and hindlimb includes the presence of an additional chondral element, which occurs during the formation of Distal Carpal 5 and the transient formation of Distal Tarsal 4 before the latter is incorporated in the cartilaginous distal end of the fibular. Some osteological aspects of other australobatrachian anurans also are reviewed (e.g., presence of intervertebral discs) based on reports in the literature, as well as first hand observations. In the course of this study, it became evident that further osteological studies are needed to formulate a clear picture of the evolution of skeletal characters not only within Australobatrachia, but also within Neobatrachia. J. Morphol., 2015. © 2015 Wiley Periodicals, Inc.
Evaluation of discriminant functions for sexing skulls from visually assessed traits applied in the Rainer Osteological Collection (Bucharest, Romania)
- Homo : internationale Zeitschrift für die vergleichende Forschung am Menschen
- Published almost 5 years ago
The sexing of human skeletal remains based on visual scoring of descriptive traits on the skull is useful for both forensic and bioarchaeological studies, given that many such features preserve well in the field and can be assessed quickly. The goal of our work is to evaluate the accuracy of this method on an age-balanced, known sex, random sample of 360 modern adult crania in the Rainer Osteological Collection. Consistent with Walker (2008), we scored glabella area (G), the mastoid process (Ma), the mental eminence (M), the orbital edge (O) and the nuchal crest (N), on a five-point scale. We generated sex discriminant functions (logistic), selected the most accurate of them, and subsequently applied them to archaeological samples from Romania. Each skull feature showed significant score differences by sex. Eight out of 31 discriminant functions passed criteria of high accuracy (∼90%), sex bias (±2%), and ease of use (direct calculation of sex). The best estimates were obtained for the 30-60 age groups. Further testing these functions on six archaeological samples showed high percentages of agreement with the sex assessed on the coxal bone. The study also indicated that, although easy to learn by novices, the method of visually scoring the skull traits depends on prior experience with human osteology. The accuracy of the method may be influenced by geographical and historical differences which are bound to exist between populations.