A case of elongated styloid process in a modern-age skull from Puerto Cabello, Venezuela

Background: The styloid process (SP) arises from cartilage of the second branchial arch and tends to calcify during later life. If the length of the SP is more than 30 mm, it can be considered abnormally elongated. Clinical symptoms associated with elongation of this type are defined as Eagle’s syndrome. The paper presents a case of an elongated SP in a modern skull from Puerto Cabello, Venezuela, obtained from a series of skulls of African slaves kept at the Department of Anthropology, Polish Academy of Sciences in Wroclaw. Materials and methods: The skull belonged to a male individual, aged ca. 55 years at death (maturus). In terms of basic anthropometric features it had slightly greater facial width parameters in comparison to the cerebral part, and a shorter length of neurocranium when compared to average values of morphological features in African skulls from Uganda. Results: Further macroscopic analysis revealed the presence of an elongated SP (ca. 70.1 mm) with secondary lesions remaining after a healed fracture. Imaging of the bone structure of the elongated SP was carried out using a computed to­mography scan, with multilevel image analysis without contrast. The elongation and calcification of the left ligament in anterior orientation could have caused irritation to the structure of cranial nerves, running within the parapharyngeal space, and to sympathetic fibres running in the wall of cervical arteries. Conclusions: Analyses of craniological materials recovered during excavations or as part of old osteological collections are rare due to the fragility of this bone structure, and for that reason they may be a valuable source of information on the health status of historic human populations

Radiation spectra of warm and optically thick coronae in AGNs

International audienceA soft X-ray excess above the 2–10 keV power-law extrapolation is generally observed in the X-ray spectra of active galactic nuclei. The origin of this excess is still not well understood. Presently there are two competitive models: blurred ionized reflection and warm Comptonization. In the case of warm Comptonization, observations suggest a corona temperature in the range 0.1–2 keV and a corona optical depth of about 10–20. Moreover, radiative constraints from spectral fits with Comptonization models suggest that most of the accretion power should be released in the warm corona and the disk below is basically non-dissipative, radiating only the reprocessed emission from the corona. However, the true radiative properties of such a warm and optically thick plasma are not well known. For instance, the importance of the Comptonization process, the potential presence of strong absorption and/or emission features, and the spectral shape of the output spectrum have been studied only very recently. Here, we present simulations of warm and optically thick coronae using the TITAN radiative transfer code coupled with the NOAR Monte-Carlo code, the latter fully accounting for Compton scattering of continuum and lines. Illumination from above by hard X-ray emission and from below by an optically thick accretion disk are taken into account, as well as (uniform) internal heating. Our simulations show that for a large part of the parameter space, the warm corona with sufficient internal mechanical heating is dominated by Compton cooling and neither strong absorption nor emission lines are present in the outgoing spectra. In a smaller part of the parameter space, the calculated emission agrees with the spectral shape of the observed soft X-ray excess. Remarkably, this also corresponds to the conditions of radiative equilibrium of an extended warm corona covering a non-dissipative accretion disk almost entirely. These results confirm that warm Comptonization is a valuable model that can explain the origin of the soft X-ray excess

Population genomics of Bronze Age Eurasia

© 2015 Macmillan Publishers Limited. All rights reserved.The Bronze Age of Eurasia (around 3000-1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought