3 research outputs found
Dental metric standards for sex estimation in archaeological populations from Iran
Sex estimation of skeletal remains is one of the major components of forensic
identification of unknown individuals. Teeth are a potential source of information on
sex and are often recovered in archaeological or forensic contexts due to their post-mortem
longevity. Currently there is limited data on dental sexual dimorphism of
archaeological populations from Iran. This dissertation represents the first study to
provide a dental sex estimation method for Iron Age populations.
The current study was conducted on the skeletal remains of 143 adults from two Iron
Age populations in close temporal and geographic proximity in the Solduz Valley
(West Azerbaijan Province of Iran). 2D and 3D cervical mesiodistal and buccolingual
and root volume measurements of maxillary and mandibular teeth were used to
investigate the degree of sexual dimorphism in permanent dentition and to assess their
applicability in sex estimation. In total 1327, 457, and 480 anterior and posterior teeth
were used to collect 2D cervical, 3D cervical, and root volume measurements
respectively. 2D cervical measurements were taken using Hillson-Fitzgerald dental
calliper and 3D measurements were collected using CT images provided by Open
Research Scan Archive (ORSA) - Penn Museum. 3D models of the teeth were created
using manual segmentation in the Amira 6.01 software package. Since tooth density
largely differs from crown to apex, root segmentation required two threshold levels:
the segmentation of the root from the jaw and the segmentation of the crown from the
root. Thresholds used for root segmentation were calculated using the half maximum
height protocol of Spoor et al. (1993) for each skull, and thresholds used for crown
segmentation were set visually for each tooth separately. Data was analysed using
discriminant function analysis and posterior probabilities were calculated for all
produced formulae where sex was previously assessed from morphological features of
pelvis and skull. Bootstrapping was used to account for small sample sizes in the
analysis. Statistical analysis was carried out using SPSS 23. The percentage of sexual
dimorphism was also used to quantify the amount of sexual dimorphism in the sample.
The results showed that incisors and canines were the most sexually dimorphic teeth,
providing percentages of correct sex classification between 80% and 100% depending
on the measurement used. Root volume measurement was shown to be the most
sexually dimorphic variable providing an accuracy of over 90% in all functions.
The present study provided the first dental metric standards for sex estimation using
odontometric data in Iranian archaeological populations. Dental measurements,
particularly root volume measurements, were found to be of value for sex assessment
and the method presented here could be a useful tool for establishing accurate
demographic data from skeletal remains of the Iron Age from Iran
Review of solar energetic particle models
Solar Energetic Particle (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to improve the scientific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data.</p
Review of Solar Energetic Particle Models
Solar Energetic Particles (SEP) events are interesting from a scientific perspective as they are the product of a broad set of physical processes from the corona out through the extent of the heliosphere, and provide insight into processes of particle acceleration and transport that are widely applicable in astrophysics. From the operations perspective, SEP events pose a radiation hazard for aviation, electronics in space, and human space exploration, in particular for missions outside of the Earth’s protective magnetosphere including to the Moon and Mars. Thus, it is critical to imific understanding of SEP events and use this understanding to develop and improve SEP forecasting capabilities to support operations. Many SEP models exist or are in development using a wide variety of approaches and with differing goals. These include computationally intensive physics-based models, fast and light empirical models, machine learning-based models, and mixed-model approaches. The aim of this paper is to summarize all of the SEP models currently developed in the scientific community, including a description of model approach, inputs and outputs, free parameters, and any published validations or comparisons with data