Latitude, urbanization, age, and sex as risk factors for vitamin D deficiency disease in the Roman Empire.

OBJECTIVES: The aims of the study are to investigate the effects of latitude, settlement type, age, and sex on the prevalence of vitamin D deficiency disease in the Roman Empire using human skeletal remains from cemetery sites (1st to 6th cent. AD). MATERIALS AND METHODS: Data from 2,787 individuals (1,143 subadults, 1,644 adults) from 18 cemeteries associated with 15 different settlements in the Mediterranean and north-western Europe were analyzed. Vitamin D deficiency disease (rickets, osteomalacia) was identified using standard paleopathological criteria. Multivariate statistical analysis was used analyze the effects of the variables of interest on the prevalence of vitamin D deficiency. RESULTS: The overall prevalence of rickets in subadults (<20 years) was 5.7%, and 3.2% of adults showed osteomalacia and/or residual rickets. There was a positive association between rickets in subadults and latitude, with numerous cases of rickets among infants. There was no general association with sex or settlement type, although an elevated prevalence of rickets was observed at a cemetery associated with a settlement (Ostia, Italy), which had multi-storey buildings. DISCUSSION: The association of rickets with latitude may reflect care practices that, in more northerly locations where solar radiation is less intense, placed infants at increased risk of insufficient sunlight exposure to permit adequate vitamin D biosynthesis. The elevated level of vitamin D deficiency at Ostia may reflect, at least in part, the lack of sunlight due to dense occupation of multi-storey blocks that prevented direct sunlight from reaching living quarters and the streets between these closely spaced buildings.

2H stable isotope analysis of human tooth enamel: a new tool for forensic human provenancing?

Stable isotope analysis of biogenic tissues such as tooth enamel and bone mineral has become a well-recognised and increasingly important method for determining the provenance of human remains, and it has been used successfully in bio-archaeological studies as well as forensic investigations. In particular, (18)O and (2)H stable isotope signatures of bone and hair, respectively, are well-established proxies of climate (temperature) and source water and are therefore considered as indicators of geographic life trajectories of animals and humans. While the methodology for (2)H analysis of human hair, fingernails, and bone collagen is currently used to determine human provenance, i.e. geographic origin and identify possible migration patterns, studies involving the analysis of (2)H in tooth enamel appear to be nonexistent in the scientific literature. Ground tooth enamel was analysed by continuous-flow isotope ratio mass spectrometry (IRMS) coupled on-line to a high-temperature conversion elemental analyser (TC/EA). An array of tooth enamel samples from archaeological and modern teeth has been analysed under different experimental conditions, and the results of this proof-of-concept study are presented. While no significant differences in (2)H abundance were noted as a result of H exchange studies or different sample preparation protocols, no significant differences or trends in measured δ(2)H-values were observed either with regard to known differences in geographical provenance. We concluded that the δ(2)H-values obtained from tooth enamel could not be used as proxy for a person's geographical origin during adolescence.

Climate change, flow regulation and land-use effects on the hydrology of the Peace-Athabasca-Slave System; findings from the Northern Rivers Ecosystem Initiative.

The Northern Rivers Ecosystem Initiative (NREI) was established in the late 1990s to address important science questions resulting from previous studies undertaken by the Northern Rivers Basin Study (NRBS). This manuscript summarizes the results from a number of reports on hydrologic research conducted on the Peace-Athabasca-Slave river and lake systems. Specific concerns expressed by the NRBS and subsequent NREI focused on how these systems were being affected by climate change, flow regulation and land-use changes. Issues addressed in this report include: the fate of aquatic perched basins within the Peace-Athabasca Delta under historical and future climate trends; the sources of major floods that replenish these basins and how the frequency, magnitude and source areas of such events have changed over time; the synoptic weather patterns and atmospheric teleconnections that are responsible for the generation of major snowmelt runoff that drive major floods; the potential effect that climate and land-use changes might have on basin runoff and delta lake levels; the specific hydro-climatic conditions required to produce major ice-jam floods on the Peace River and how these may be altered by climate change; remote-sensing methods to document delta flooding and vegetation change; and the dual effect of climate and flow regulation on the water levels of Great Slave Lake and how these may affect other nearshore processes, particularly wind seiches, that influence flooding of the Slave River Delta. A review of the major findings and recommendations for future research concludes the report.

Concordance of cranial and dental morphological traits and evidence for endogamy in ancient Egypt.

A biological affinities study based on frequencies of cranial nonmetric traits in skeletal samples from three cemeteries at predynastic Naqada, Egypt, confirms the results of a recent nonmetric dental morphological analysis. Both cranial and dental traits analyses indicate that the individuals buried in a cemetery characterized archaeologically as high status are significantly different from individuals buried in two other, apparently nonelite cemeteries and that the nonelite samples are not significantly different from each other. A comparison with neighbouring Nile Valley skeletal samples suggests that the high status cemetery represents an endogamous ruling or elite segment of the local population at Naqada, which is more closely related to populations in northern Nubia than to neighbouring populations in southern Egypt.

Hydrometeorological aspects of flood hazards in Canada

Floods are major disasters in Canada and worldwide. Although technology has reduced the flood hazard in many areas, the world death toll from floods in recent decades still has averaged 4680 per year. During the summer of 1993, flooding in the U.S.A. caused an estimated $12 billion damage. These statistics confirm that floods are a major natural disaster. This paper reviews the hydrometereological aspects of the hazard associated with rainstorm, urban, ice-jam, and snowmelt floods. The hazard element is highest for floods with rapid onsets such as rainstorm, urban, and ice-jam floods. Although snowmelth floods are common throughout Canada, their slower onset times reduce their risk potential. To reduce the risk of the flood hazard, society must have access to statistical information for adequate planning and design, and forecasts for issuing warnings and implementing evacuation strategies. Flood design statistics and forecast models are discussed relative to each major flood type. The paper also describes historical flood frequency trends and discusses the implications of climatic warning for future floods. The paper concludes with a brief discussion of some knowledge gaps and research needs.(AU)