Intra- and inter-tooth variation in strontium isotope ratios from prehistoric seals by laser ablation multi-collector inductively coupled plasma mass spectrometry.

RATIONALE: Strontium isotope ratios (87 Sr/86 Sr) in modern-day marine environments are considered to be homogeneous (~0.7092). However, in the Baltic Sea, the Sr ratios are controlled by mixing seawater and continental drainage from major rivers discharging into the Baltic. This pilot study explores if variations in Sr can be detected in marine mammals from archaeological sites in the Baltic Sea. METHODS: 87 Sr/86 Sr ratios were measured in tooth enamel from three seal species by laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). The method enables micro-sampling of solid materials. This is the first time that the method has been applied to marine samples from archaeological collections. RESULTS: The analyses showed inter-tooth 87 Sr/86 Sr variation suggesting that different ratios can be detected in different regions of the Baltic Sea. Furthermore, the intra-tooth variation suggests possible different geographic origin or seasonal movement of seals within different regions in the Baltic Sea through their lifetime. CONCLUSIONS: The method was successfully applied to archaeological marine samples showing that: (1) the 87 Sr/86 Sr ratio in marine environments is not uniform, (2) 87 Sr/86 Sr differences might reflect differences in ecology and life history of different seal species, and (3) archaeological mobility studies based on 87 Sr/86 Sr ratios in humans should therefore be evaluated together with diet reconstruction.

Radiation exposure in patients with inflammatory bowel disease and irritable bowel syndrome in the years 2001-2011.

OBJECTIVES: To compare cumulative ionizing radiation in patients with inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) for the years 2001-2011. To study how radiation exposure change over time in patients with newly diagnosed IBD and factors associated with radiation exposure. MATERIAL AND METHODS: All radiological investigations performed between 1 January 2001 and 31 December 2011 were retrospectively recorded in patients with Crohn's disease (CD) (n = 103), ulcerative colitis (UC) (n = 304) and IBS (n = 149). Analyses were done with Mann-Whitney and Chi-Square test. RESULTS: The median total cumulative radiation exposure in mSv for CD (20.0, inter quartile range (IQR) 34.8), UC (7.01, IQR 23.8), IBS (2.71, IQR 9.15) and the proportion of patients who had been exposed for more than 50 mSv during the study period (CD 19%, UC 11%, IBS 3%) were significantly higher in the patients with CD compared to patients with UC (p < .001) and IBS (p < .001), respectively. In turn, patients with UC had significantly higher doses than patients with IBS (p = .005). Risk factors for radiation exposure were female gender (CD), early onset (UC), ileocolonic location (CD), previous surgery (CD and UC), depression (IBS) and widespread pain (IBS). In newly diagnosed CD, there was a significant decline in median cumulative radiation dose in mSv (17.2 vs. 12.0; p = .048) during the study period. CONCLUSIONS: Patients with CD are at greatest risk for high cumulative radiation exposure, but there is a decline in exposure during the late 2000s. Non-colectomized patients with UC and patients with IBS have a relatively low risk of cumulative radiation exposure.

Dating human cultural capacity using phylogenetic principles.

Humans have genetically based unique abilities making complex culture possible; an assemblage of traits which we term "cultural capacity". The age of this capacity has for long been subject to controversy. We apply phylogenetic principles to date this capacity, integrating evidence from archaeology, genetics, paleoanthropology, and linguistics. We show that cultural capacity is older than the first split in the modern human lineage, and at least 170,000 years old, based on data on hyoid bone morphology, FOXP2 alleles, agreement between genetic and language trees, fire use, burials, and the early appearance of tools comparable to those of modern hunter-gatherers. We cannot exclude that Neanderthals had cultural capacity some 500,000 years ago. A capacity for complex culture, therefore, must have existed before complex culture itself. It may even originated long before. This seeming paradox is resolved by theoretical models suggesting that cultural evolution is exceedingly slow in its initial stages.

Widespread origins of domestic horse lineages.

Domestication entails control of wild species and is generally regarded as a complex process confined to a restricted area and culture. Previous DNA sequence analyses of several domestic species have suggested only a limited number of origination events. We analyzed mitochondrial DNA (mtDNA) control region sequences of 191 domestic horses and found a high diversity of matrilines. Sequence analysis of equids from archaeological sites and late Pleistocene deposits showed that this diversity was not due to an accelerated mutation rate or an ancient domestication event. Consequently, high mtDNA sequence diversity of horses implies an unprecedented and widespread integration of matrilines and an extensive utilization and taming of wild horses. However, genetic variation at nuclear markers is partitioned among horse breeds and may reflect sex-biased dispersal and breeding.

Molecular analysis of Neanderthal DNA from the northern Caucasus.

The expansion of premodern humans into western and eastern Europe approximately 40,000 years before the present led to the eventual replacement of the Neanderthals by modern humans approximately 28,000 years ago. Here we report the second mitochondrial DNA (mtDNA) analysis of a Neanderthal, and the first such analysis on clearly dated Neanderthal remains. The specimen is from one of the eastern-most Neanderthal populations, recovered from Mezmaiskaya Cave in the northern Caucasus. Radiocarbon dating estimated the specimen to be approximately 29,000 years old and therefore from one of the latest living Neanderthals. The sequence shows 3.48% divergence from the Feldhofer Neanderthal. Phylogenetic analysis places the two Neanderthals from the Caucasus and western Germany together in a clade that is distinct from modern humans, suggesting that their mtDNA types have not contributed to the modern human mtDNA pool. Comparison with modern populations provides no evidence for the multiregional hypothesis of modern human evolution.

Dietary change and stable isotopes: a model of growth and dormancy in cave bears.

In order to discuss dietary change over time by the use of stable isotopes, it is necessary to sort out the underlying processes in isotopic variation. Together with the dietary signal other processes have been investigated, namely metabolic processes, collagen turnover and physical growth. However, growth and collagen turnover time have so far been neglected in dietary reconstruction based on stable isotopes. An earlier study suggested that cave bears (Ursus spelaeus) probably gave birth to cubs during dormancy. We provide an estimate of the effect on stable isotopes of growth and metabolism and discuss collagen turnover in a population of cave bears. Based on a quantitative model, we hypothesized that bear cubs lactated their mothers during their first and second winters, but were fed solid food together with lactation during their first summer. This demonstrates the need to include physical growth, metabolism and collagen turnover in dietary reconstruction. Whereas the effects of diet and metabolism are due to fractionation, growth and collagen turnover are dilution processes.

Stable isotopes and the metabolism of the European cave bear.

Isotopic analyses of fossil bones of the extinct European cave bear indicate that this animal was a hibernator with the same unusual metabolic processes as some modern bear species. This finding provides useful biological and archaeological information on an extinct species, and the methods themselves may prove generally useful in studies of the metabolisms of modern bears, other hibernators, and perhaps of starving animals.

Taking the 5000 year old "Jettböle skeletons" out of the closet: a palaeo-medical examination of human remains from the Aland (Ahvenanmaa) Islands.

Results of a somewhat preliminary bioanthropological study on the skeletal material from the Pitted ware site of jettböle, excavated in the parish of jomala, Aland (Ahvenanmaa) Islands, some 85-90 years ago are presented, and the causes for the disorderly distribution, including the possibility of cannibalism, are discussed.

Ultrastructural variations following use of several weakly protic alcohols as dehydration agents.

Evaluation has been made of ultrastructural variations which obtain following dehydration and infiltration of glutaraldehyde plus osmium fixed CHO cells with the weakly protic alcohols (methanol, ethanol, ethylene glycol, 1-propanol, 2-propanol, propylene glycol and glycerine), acetone alone, and with use of acetone and propylene oxide as transition solvents subsequent to dehydration with ethanol, methanol and ethylene glycol. It appears that the weakly protic alcohols, applied without transition solvent, in addition to some extraction by themselves, variously condition the components of membranes, etc, for possible further extraction by the embedment resin. Extraction by embedment consists mainy of removal of aggregate or 'corpuscular' units from regions assumed to have originally consisted of endomembrane. Relatively discrete extraction pits in membranes are noted in the cases of methanol and ethylene glycol dehydration without transition solvent; whereas use of the other alcohols such as 1-propanol and 2-propanol accentuate the visualization and staining of mitochondrial ribosomes. Cytoplasmic ribosomes stain more strongly when acetone or ethylene glycol are employed as dehydration agents, but some size (length) differences obtain. Apparently, acetone or propylene oxide transition following dehydration with ethanol or methanol (but not the glycols) assists in, or fixes, alterations of endomembrane components into the familiar 'unit membrane' orientation upon which the embedding substances have little discernible effect. Glycol dehydration and infiltration regimens (especially ethylene glycol alone and as a dehydration agent in the application of Bernhard's (1969) staining technique) result in lesser electron density of heterochromatin while accentuating RNP particles. The increased electron density of heterochromatin while accentuating RNP particles. The increased electron density of the RNP particles and the decrease in density of the heterochromatin result in improved visualization of the relationships among nucleolar RNP particles and the nuclear pore complexes.

X-ray fluorescence analysis of lead in human skeleton in vivo.

The lead concentration in the skeleton of living man was measured by X-ray fluorescence analysis. Five former workers from a metal industry were studied. The mean lead concentration in their skeletons was estimated to be 62 mug/g with a standard error of +/- 5 mug/g. A comparison with the "normal" skeletal concentrations of lead in people from southern Sweden showed the skeletal concentrations of the men studied to be about three to nine times higher.

The new special names of SI units in the field of ionizing radiations.

New SI units for ionizing radiations have been recommended by the internation Commission on Radiation Units and Measurements (ICRU). These are the becquerel (symbol Bq), equal to the second to the power -1, and the gray (symbol Gy), equal to the joule per kilogram. It was recommended that the roentgen be replaced as the unit of exposure by the coulomb per kilogram (C/kg), for which no new name was proposed. The ICRU recommends that the units rad, roentgen, and curie be gradually abandoned over a period of ten years and that preparatory steps to this end be taken as soon as possible by various national and international bodies in order to facilitate a smooth, safe, and efficient transition.

The new special names of SI units in the field of ionizing radiations.

At its meeting in May-June 1975, the 15th Conference Generale des Poids et Mesures adopted two new special names of SI units; the becquerel, symbol Bq, equal to the second to the power minus one, s-1, for the quantity activity, and the gray, symbol Gy, equal to the joule per kilogram, J-kg-1, for absorbed dose and related quantities in the field of ionizing radiations. This action was preceded by a recommendation of the International Commission on Radiation Units and Measurements (ICRU) in 1974.