240 research outputs found
(Re)discovering the Gaulcross Hoard
Acknowledgements We would like to thank Charles and Helen Gray for permitting access to the land and for support in the excavation of the hoard. Thanks also to Bruce Mann and the Aberdeenshire Council Archaeology Service for advice and supporting the radiocarbon dating. Fraser Hunter and Tanja Romankiewicz assisted during a very cold excavation. Fraser and Alice Blackwell kindly read and commented on drafts of this paper. The fieldwork was funded through a donation to the University of Aberdeen's Development Trust and undertaken as part of the Northern Picts project, in association with the Tarbat Discovery Centre.Peer reviewedPostprin
The development of the Pictish symbol system : inscribing identity beyond the edges of Empire
Thanks go to Gail Drinkall (Orkney Museum) and our funders: Aberdeenshire Council Archaeology Service, Historic Environment Scotland, The Strathmartine Trust and the University of Aberdeen Development Trust. Isabel Henderson helped to refine Table 1. Fraser Hunter and Alice Blackwell read and commented on an earlier draft. The writing of this article was also supported by a Leverhulme Trust Research Leadership Award (RL-2016-069).Peer reviewedPublisher PD
Death and Display in the North Atlantic: The Bronze and Iron Age Human Remains from Cnip, Lewis, Outer Hebrides
YesThis paper revisits the series of disarticulated human remains discovered during the 1980s excavations of the Cnip wheelhouse complex in Lewis. Four fragments of human bone, including two worked cranial fragments, were originally dated to the 1st centuries BC/AD based on stratigraphic association. Osteoarchaeological reanalysis and AMS dating now provide a broader cultural context for these remains and indicate that at least one adult cranium was brought to the site more than a thousand years after the death of the individual to whom it had belonged
Incidence, severity, aetiology and type of neck injury in men's amateur rugby union: a prospective cohort study
<p>Abstract</p> <p>Background</p> <p>There is a paucity of epidemiological data on neck injury in amateur rugby union populations. The objective of this study was to determine the incidence, severity, aetiology and type of neck injury in Australian men's amateur rugby union.</p> <p>Methods</p> <p>Data was collected from a cohort of 262 participants from two Australian amateur men's rugby union clubs via a prospective cohort study design. A modified version of the Rugby Union Injury Report Form for Games and Training was used by the clubs physiotherapist or chiropractor in data collection.</p> <p>Results</p> <p>The participants sustained 90 (eight recurrent) neck injuries. Exposure time was calculated at 31143.8 hours of play (12863.8 hours of match time and 18280 hours of training). Incidence of neck injury was 2.9 injuries/1000 player-hours (95%CI: 2.3, 3.6). As a consequence 69.3% neck injuries were minor, 17% mild, 6.8% moderate and 6.8% severe. Neck compression was the most frequent aetiology and was weakly associated with severity. Cervical facet injury was the most frequent neck injury type.</p> <p>Conclusions</p> <p>This is the first prospective cohort study in an amateur men's rugby union population since the inception of professionalism that presents injury rate, severity, aetiology and injury type data for neck injury. Current epidemiological data should be sought when evaluating the risks associated with rugby union football.</p
Free radical generation by skeletal muscle of adult and old mice: effect of contractile activity
Oxidative modification of cellular components may contribute to tissue dysfunction during aging. In skeletal muscle, contractile activity increases the generation of reactive oxygen and nitrogen species (ROS). The question of whether contraction-induced ROS generation is further increased in skeletal muscle of the elderly is important since this influences recommendations on their exercise participation. Three different approaches were used to examine whether aging influences contraction-induced ROS generation. Hind limb muscles of adult and old mice underwent a 15-min period of isometric contractions and we examined ROS generation by isolated skeletal muscle mitochondria, ROS release into the muscle extracellular fluid using microdialysis techniques, and the muscle glutathione and protein thiol contents. Resting skeletal muscle of old mice compared with adult mice showed increased ROS release from isolated mitochondria, but no changes in the extracellular levels of superoxide, nitric oxide, hydrogen peroxide, hydroxyl radical activity or muscle glutathione and protein thiol contents. Skeletal muscle mitochondria isolated from both adult and old mice after contractile activity showed significant increases in hydrogen peroxide release compared with pre-contraction values. Contractions increased extracellular hydroxyl radical activity in adult and old mice, but had no significant effect on extracellular hydrogen peroxide or nitric oxide in either group. In adult mice only, contractile activity increased the skeletal muscle release of superoxide. A similar decrease in muscle glutathione and protein thiol contents was seen in adult and old mice following contractions. Thus, contractile activity increased skeletal muscle ROS generation in both adult and old mice with no evidence for an age-related exacerbation of ROS generation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72706/1/j.1474-9726.2006.00198.x.pd
The age-related failure of adaptive responses to contractile activity in skeletal muscle is mimicked in young mice by deletion of Cu,Zn superoxide dismutase
In muscle, aging is associated with a failure of adaptive responses to contractile activity, and this is hypothesized to play an important role in age-related loss of muscle mass and function. Mice lacking the Cu,Zn superoxide dismutase (Cu,ZnSOD, SOD1) show an accelerated, age-related loss of muscle mass and function. This work determined whether adult mice lacking Cu,ZnSOD ( Sod1 −/− mice) show a premature failure of adaptive responses to contractions in a similar manner to old wild-type (WT) mice. Adult Sod1 −/− mice (6–8 months of age) had a ∼ 30% reduction in gastrocnemius muscle mass compared with age-matched WT mice. This lower muscle mass was associated with an activation of DNA binding by NFκB and AP-1 at rest. Measurements of the activity of reactive oxygen species (ROS) in single fibres from the muscles of Sod1 −/− mice at rest indicated an elevation in activity compared with fibres from WT mice. Following 15 min of isometric contractions, muscle fibres from WT mice showed an increase in the intracellular ROS activities and activation of NFκB and AP-1, but no changes in either ROS activity or NFκB and AP-1 activation were seen in the muscles of Sod1 −/− mice following contractions. This pattern of changes mimics that seen in the muscles of old WT mice, suggesting that the attenuated responses to contractile activity seen in old mice result from chronic exposure to increased oxidant activity. Data support the use of the Sod1 −/− mouse model to evaluate potential mechanisms that contribute to the loss of muscle mass and function in the elderly.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79367/1/j.1474-9726.2010.00635.x.pd
Measurement of the Nucleon Structure Function F2 in the Nuclear Medium and Evaluation of its Moments
We report on the measurement of inclusive electron scattering off a carbon
target performed with CLAS at Jefferson Laboratory. A combination of three
different beam energies 1.161, 2.261 and 4.461 GeV allowed us to reach an
invariant mass of the final-state hadronic system W~2.4 GeV with four-momentum
transfers Q2 ranging from 0.2 to 5 GeV2. These data, together with previous
measurements of the inclusive electron scattering off proton and deuteron,
which cover a similar continuous two-dimensional region of Q2 and Bjorken
variable x, permit the study of nuclear modifications of the nucleon structure.
By using these, as well as other world data, we evaluated the F2 structure
function and its moments. Using an OPE-based twist expansion, we studied the
Q2-evolution of the moments, obtaining a separation of the leading-twist and
the total higher-twist terms. The carbon-to-deuteron ratio of the leading-twist
contributions to the F2 moments exhibits the well known EMC effect, compatible
with that discovered previously in x-space. The total higher-twist term in the
carbon nucleus appears, although with large systematic uncertainites, to be
smaller with respect to the deuteron case for n<7, suggesting partial parton
deconfinement in nuclear matter. We speculate that the spatial extension of the
nucleon is changed when it is immersed in the nuclear medium.Comment: 37 pages, 15 figure
Phosphorus recycling in photorespiration maintains high photosynthetic capacity in woody species
Leaf photosynthetic CO2 responses can provide insight into how major nutrients, such as phosphorus (P), constrain leaf CO2 assimilation rates (Anet). However, triose-phosphate limitations are rarely employed in the classic photosynthesis model and it is uncertain as to what extent these limitations occur in field situations. In contrast to predictions from biochemical theory of photosynthesis, we found consistent evidence in the field of lower Anet in high [CO2] and low [O2] than at ambient [O2]. For 10 species of trees and shrubs across a range of soil P availability in Australia, none of them showed a positive response of Anet at saturating [CO2] (i.e. Amax) to 2 kPa O2. Three species showed >20% reductions in Amax in low [O2], a phenomenon potentially explained by orthophosphate (Pi) savings during photorespiration. These species, with largest photosynthetic capacity and Pi > 2 mmol P m−2, rely the most on additional Pi made available from photorespiration rather than species growing in P-impoverished soils. The results suggest that rarely used adjustments to a biochemical photosynthesis model are useful for predicting Amax and give insight into the biochemical limitations of photosynthesis rates at a range of leaf P concentrations. Phosphate limitations to photosynthetic capacity are likely more common in the field than previously considered
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