34 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
A quasi-experimental examination of how school-based physical activity changes impact secondary school student moderate- to vigorous- intensity physical activity over time in the COMPASS study
Risk factors in the Midspan family study by social class in childhood and adulthood
BACKGROUND Social class in childhood and in adulthood have been shown to be important determinants of risk factors in later life. Often the childhood information is retrospective and liable to bias. We use data from a family study of two generations of adults to investigate the effects of social class in childhood, adulthood and social mobility on risk factors. METHODS In 1996, 2338 adult offspring of participants of the 1970s Renfrew/Paisley study took part in a screening examination. They provided information on sociological, behavioural and clinical risk factors, as their parents had done 20 years previously. Social class and father's social class were available, enabling their influence on risk factors to be investigated. RESULTS Generally risk factors improved for offspring compared with parents, except for Body mass index and obesity, which worsened. Risk factors were less favourable in manual compared with non-manual offspring, and were more closely related to own than father's social class. There was a large amount of upward social mobility involving 35% of sons and 50% of daughters. Risk factors for the upwardly mobile tended to be more favourable than the class they left behind but less favourable than the class they joined. CONCLUSIONS The concomitants of social mobility may reflect behavioural choices, such as smoking, and adverse factors, which are more difficult to leave behind. The relatively fast changes in social class profile may not be reflected in as quick changes in population health, as the upwardly mobile bring their earlier life adversities with them
A cross-sectional survey to determine the ages of emergence of permanent teeth of Caucasian children of the Colchester area of the UK
Body Mass Index and Waist Circumference in Relation to Lung Cancer Risk in the Women's Health Initiative
Investigators in several epidemiologic studies have observed an inverse association between body mass index (BMI) and lung cancer risk, while others have not. The authors used data from the Women's Health Initiative to study the association of anthropometric factors with lung cancer risk. Over 8 years of follow-up (1998–2006), 1,365 incident lung cancer cases were ascertained among 161,809 women. Cox proportional hazards models were used to estimate hazard ratios adjusted for covariates. Baseline BMI was inversely associated with lung cancer in current smokers (highest quintile vs. lowest: hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.42, 0.92). When BMI and waist circumference were mutually adjusted, BMI was inversely associated with lung cancer risk in both current smokers and former smokers (HR = 0.40 (95% CI: 0.22, 0.72) and HR = 0.61 (95% CI: 0.40, 0.94), respectively), and waist circumference was positively associated with risk (HR = 1.56 (95% CI: 0.91, 2.69) and HR = 1.50 (95% CI: 0.98, 2.31), respectively). In never smokers, height showed a borderline positive association with lung cancer. These findings suggest that in smokers, BMI is inversely associated with lung cancer risk and that waist circumference is positively associated with risk