173 research outputs found
A multi-isotope investigation of diet and subsistence amongst island and mainland populations from early medieval western Britain
Objectives: This is the first investigation of dietary practices amongst multiple early medieval populations (AD 500â1000) from Wales and the Isle of Man using carbon, nitrogen, and sulphur isotope analysis. The analysis will illuminate similarities or differences between the diets and subsistence strategies of populations occupying different geographical regions, specifically those living in marginal coastal regions in comparison to inland populations well-connected to ecclesiastical centres and high-status settlements.
Materials and Methods: One hundred and two human skeletons were sampled for carbon and nitrogen isotope analysis, and 69 human skeletons were sampled for sulphur isotope analysis from nine cemetery sites from western Britain (Isle of Manâ=â3, southwest Walesâ=â4, southeast Walesâ=â2). Thirteen faunal skeletons from St Patrick's Chapel (southwest Wales) were sampled for carbon, nitrogen, and sulphur isotope analysis.
Results: Human δ13C values range from â19.4â° to â21.2â° (δ13C mean=â20.4 Âą0.4â°, 1Ď, nâ=â86), and δ15N values range from 9.1â° to 13.8â° (δ15N mean = 10.8âÂąâ0.9â°, 1Ď, nâ=â86). δ34S values range from 1.2â° to 18.4â° (δ34S mean = 11.6âÂąâ4.5â°, 1Ď, nâ=â66). Significant differences were noted between the mean δ13C, δ15N and δ34S values according to geographic region: Isle of Man (δ13Câ=ââ20.7 Âą 0.4â°, δ15Nâ=â11.4 Âą0.6â°, nâ=â13/86; δ34S meanâ=â17.1 Âą0.6, nâ=â4/66), southwest Wales (δ13Câ=ââ20.5 Âą 0.4â°, δ15Nâ=â11.0 Âą1â°, nâ=â32/86; δ34Sâ=â16.1 Âą 2.1, nâ=â21/66), and southeast Wales (δ13C =â20.3 Âą0.4â°, δ15Nâ=â10.4 Âą0.7â°, nâ=â41/86; δ34S= 8.8 Âą3â°, nâ=â41/66). Faunal δ13C values range from â23.1â° to â21.2â° (δ13C mean= â22.1 Âą0.5â°, 1Ď, nâ=â13), and δ15N values range from 6.3â° to 9.8â° (δ15N mean = 7.3âÂąâ1.1â°, 1Ď, nâ=â13). δ34S values range from 4.7â° to 18.4â° (δ34S mean= 16.3âÂąâ3.6â°, 1Ď, nâ=â13).
Conclusions: The data reveal a reliance on terrestrial protein, however differences are observed between the resource consumption of populations from southwest Wales and the Isle of Man in comparison to the populations from southeast Wales. Populations from the west coast have a marine sulphur signature that reflects their coastal proximity and may also include a reliance on seaweed as a fertiliser/food source. Populations in the southeast were connected to ecclesiastical centres and high-status settlements and had access to inland-grown produce. The data add support to the suggestion that δ34S can be used as a mobility indicator
Investigation of sulphate sulphur isotope variations in the Skerne Magnesian Limestone water body
This report presents the results of a sulphur isotope investigation undertaken in the Skerne
catchment, located in County Durham, north of Darlington, to investigate the source of
groundwater sulphate in the Magnesian Limestone Aquifer. Groundwater and surface waters in
the catchment are at risk from a number of current and historic anthropogenic activities. Sulphate
is the biggest risk to the public water supplies; as there is currently no cost-effective treatment
available and it could render supplies unusable. The elevated sulphate could be both naturally
occurring, due to the presence of gypsum or anhydrite bands in the Magnesian Limestone, or it could
be due to abandoned coal mine water, or even saline intrusion pollution. Because of the large
difference in the sulphate sulphur isotope composition expected between âmarine sulphateâ,
including sulphate derived from marine evaporites, and ânon-marine sulphateâ derived from the
oxidation of sulphide in the coal seams and mine workings, sulphur isotopes were considered
promising tracers to discern mine water sources from natural Permian evaporite sources of
sulphate.
A survey was carried out at 28 sites where groundwater was sampled in July 2018 from boreholes
in the Magnesian Limestone Aquifer and in the Coal Measures, following a pilot study comprising
7 boreholes in July 2017. A small number of surface waters, hyporheic zone waters, springs, and
soil leachates, sampled during 2017-2018, were also analysed for sulphur isotopes to
complement the borehole data. This has allowed the characterisation of the sulphur isotope
composition of potential sources of dissolved sulphate.
Most of the Magnesian Limestone aquifer groundwaters cluster close to the Global Meteoric
Water Line (GMWL) on the dual water δ
18O and δ2H graph with no evidence of mixing with Narich coal mine water, the latter being more depleted in 18O and 2H; there is a small number of
boreholes immediately in proximity of the coal seam boreholes, clearly showing signs of water
mixing. With higher δ18O and δ2H than the main Magnesian Limestone group, and slightly offset
from the GMWL, is also a small group of Magnesian Limestone boreholes. Repeated sampling
would better discern the different recharge paths suggested by this single sampling event in July
2018.
Groundwaters associated with the worked and unworked coal seam boreholes in this study are
of two water types: sodium sulphate (NaâSO4) and sodium bicarbonate (NaâHCO3) waters,
variably enriched in dissolved sulphate. Two δ
34S measurements of the dissolved sulphate in the
NaâSO4 coal seam boreholes are +13.1â° and +23.4â°. The lack of the more typical 34S-depleted
sulphate derived from the oxidation of pyrite is hence apparent. A similar range of high sulphate
δ
34S values has been described in recent studies, and attributed to deep coal mine systems.
From a review of published δ34S values for marine evaporites, groundwaters containing sulphate
solely derived from the dissolution of Permian marine evaporites are characterised by 34Senriched sulphate (δ34S values range from +8.2 to +11.1â°).
There is, therefore, less of a contrasting isotope signature between potential âevaporiteâ and âcoal
mine waterâ end-members. For example, one sample of coal mine water with δ
34S values of
+13.1Ⱐis not too dissimilar to the average Permian evaporite sulphate with δ
34S value of around
+10â°. This makes discrimination of the dissolved sulphate sources based on sulphur isotope
less certain, especially at low sulphate concentrations.
To help the data interpretation, we have modelled the sulphate and sulphur isotope compositions
of mixtures of hypothetical end-members and used the evidence from these simulations to
constrain possible groundwater contributions and mixing. In particular we simulate how the
HARDWICK HALL borehole, representing the Magnesian Limestone aquifer background, with a
sulphate concentration of 89 mg/l, and a δ34S value of +1.0â°, evolves during mixing with the
following end-members: i) the coal mine waters in this study, ii) a Permian evaporite source, iii)
seawater and iv) acid mine drainage.
A summary of the data interpretation based on the above modelling is as follows.
Over the mine plume area, inputs of coal mine water-derived sulphate are significant in at least
one Magnesian Limestone borehole, and detectable in others, supported by the water isotope δ
18O and δ2H data, indicating for these samples water mixing between the coal mine water and
the Magnesian Limestone aquifer.
Among the Magnesian Limestone boreholes, where gypsum or anhydrite were noted in the
borehole logs, only DALTON PIERCY NO 3 and NO 6 boreholes have high sulphate
concentrations and display constant δ
34S values of +10.2â°. Given how close this value is to the
Permian evaporitesâ δ34S values, it could be plausibly explained by a gypsum dissolution source,
although a âcoal mine waterâ contribution with a δ34S signature of +13â° cannot be totally
excluded, as shown by the mixing curves. Many of the Magnesian Limestone boreholes with a
sulphate concentration around 100 mg/l (range 85â130 mg/l) are characterised instead by a low
δ
34S range (-0.7 to +7.2â°). For most of these low sulphate Magnesian Limestone boreholes,
uncertainties in discriminating the source of sulphate are higher.
The contribution of sulphate from seawater is difficult to discern in the present data for the saline
waters of HART RESERVOIR and HARTLEPOOL IND ESTATE REPLACEMENT boreholes, with
similar δ34S values of +21.1â° and +27â°, as they fall far away from the SeawaterâMagnesian
Limestone mixing line.
Many samples fall far outside of these mixing envelopes, suggesting non-conservative behaviour
of the sulphate. The very high δ34S and low sulphate concentrations can be interpreted as a
possible sign of reduction of sulphates and enrichment in the heavier 34S isotope of the residual
(low concentration) sulphate.
Additional samples obtained during this study include: i) A spring in the Ford Formation from
AYCLIFFE QUARRY to the south east of Aycliffe Village which provides an additional background
sample characterised for sulphur isotopes. The water has a SO4 of 69 mg/l and a δ34S value of
+2.3â° and well resembles the composition of HARDWICK HALL borehole. ii) A MgâSO4 spring,
sampled in Woodham Burn and described in previous studies for its impact on the surface water
quality because of its high sulphate concentrations of ~800 mg/l. It has a stable δ34S value of ~
+5.5â°. iii) a surface water impacted by mine water inflow with a MgâSO4 composition, and a δ34S
value of +6.9â°.
The δ34S value of +5.5Ⱐof the Mg-SO4 spring at Woodham Burn points to a contribution of low
δ
34S-sulphate, as expected from the oxidation of pyrite. These data support the mechanism,
hypothesised in Palumbo-Roe et al. (2020) to account for the spring composition, of dissolution
of dolomite in the presence of acidic water, where the source of acidity comes from coal mine
water due to the oxidation of pyrite.
There is a much narrower and lower range of δ
34S in surface water compared to the groundwater
samples. With most δ
34S values less than +7â°, none of the high values measured in the
boreholes were noted in the surface water, hyporheic zone or soil leachate samples, except for
two samples in the hyporheic zone of Woodham Burn with δ
34S +36.3â° and +13.4â°, values
taken as further evidence of the sulphate reduction during the 2018 summer indicated by the
hydrochemistry.
Recommendations for future work, building upon these findings, are suggested
Laser spectroscopy of hyperfine structure in highly-charged ions: a test of QED at high fields
An overview is presented of laser spectroscopy experiments with cold,
trapped, highly-charged ions, which will be performed at the HITRAP facility at
GSI in Darmstadt (Germany). These high-resolution measurements of ground state
hyperfine splittings will be three orders of magnitude more precise than
previous measurements. Moreover, from a comparison of measurements of the
hyperfine splittings in hydrogen- and lithium-like ions of the same isotope,
QED effects at high electromagnetic fields can be determined within a few
percent. Several candidate ions suited for these laser spectroscopy studies are
presented.Comment: 5 pages, 1 figure, 1 table. accepted for Canadian Journal of Physics
(2006
Multi-isotope analysis reveals that feasts in the Stonehenge environs and across Wessex drew people and animals from throughout Britain.
The great henge complexes of southern Britain are iconic monuments of the third millennium BCE, representing great feats of engineering and labor mobilization that hosted feasting events on a previously unparalleled scale. The scale of movement and the catchments that the complexes served, however, have thus far eluded understanding. Presenting the largest five-isotope system archeological dataset (87Sr/86Sr, δ34S, δ18O, δ13C, and δ15N) yet fully published, we analyze 131 pigs, the prime feasting animals, from four Late Neolithic (approximately 2800 to 2400 BCE) complexes to explore the networks that the feasts served. Because archeological evidence excludes continental contact, sources are considered only in the context of the British Isles. This analysis reveals wide-ranging origins across Britain, with few pigs raised locally. This finding demonstrates great investment of effort in transporting pigs raised elsewhere over vast distances to supply feasts and evidences the very first phase of pan-British connectivity
Neutrino Interactions in Hot and Dense Matter
We study the charged and neutral current weak interaction rates relevant for
the determination of neutrino opacities in dense matter found in supernovae and
neutron stars. We establish an efficient formalism for calculating differential
cross sections and mean free paths for interacting, asymmetric nuclear matter
at arbitrary degeneracy. The formalism is valid for both charged and neutral
current reactions. Strong interaction corrections are incorporated through the
in-medium single particle energies at the relevant density and temperature. The
effects of strong interactions on the weak interaction rates are investigated
using both potential and effective field-theoretical models of matter. We
investigate the relative importance of charged and neutral currents for
different astrophysical situations, and also examine the influence of
strangeness-bearing hyperons. Our findings show that the mean free paths are
significantly altered by the effects of strong interactions and the
multi-component nature of dense matter. The opacities are then discussed in the
context of the evolution of the core of a protoneutron star.Comment: 41 pages, 25 figure
Multi-Level Assessment Protocol (MAP) for Adoption in Multisite Clinical Trials
The National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) is intended to test promising drug abuse treatment models in multisite clinical trials and to support adoption of new interventions into clinical practice. Using qualitative research methods we asked the following question: how might the technology of multisite clinical trials be modified to better support adoption of tested interventions? A total of 42 participants, representing eight organizational levels ranging from clinic staff to clinical trial leaders, were interviewed about their role in the clinical trial, its interactions with clinics, and intervention adoption. Among eight clinics participating in the clinical trial, we found adoption of the tested intervention in one clinic only. Analysis of interview data revealed four conceptual themes likely to affect adoption and may be informative in future multisite clinical trials. Planning for adoption in the early stages of protocol development will better serve the aim of integrating new interventions into practice
The preservation and interpretation of δ34 S values in charred archaeobotanical remains
The measurement of sulphur isotope (δ34S) values in charred plant remains has the potential to inform understanding of the spatial configuration and ecology of crop production. We investigated the effects of charring, manuring, oxidation and anaerobic soil conditions on modern cereal grain/pulse seed δ34S values, and assessed the effect of chemical preâtreatment on charred modern and archaeobotanical grain/seed δ34S values. We used these results to interpret δ34S values in archaeobotanical material from Neolithic ĂatalhĂśyĂźk. Our results suggest that δ34S values can be reliably preserved in charred grain/seeds but are subject to influence by anaerobic soil conditions, the effect depending on the timing of flooding in relation to S assimilation
Consensusâbased technical recommendations for clinical translation of renal phase contrast MRI
Background
Phaseâcontrast (PC) MRI is a feasible and valid noninvasive technique to measure renal artery blood flow, showing potential to support diagnosis and monitoring of renal diseases. However, the variability in measured renal blood flow values across studies is large, most likely due to differences in PCâMRI acquisition and processing. Standardized acquisition and processing protocols are therefore needed to minimize this variability and maximize the potential of renal PCâMRI as a clinically useful tool.
Purpose
To build technical recommendations for the acquisition, processing, and analysis of renal 2D PCâMRI data in human subjects to promote standardization of renal blood flow measurements and facilitate the comparability of results across scanners and in multicenter clinical studies.
Study Type
Systematic consensus process using a modified Delphi method.
Population
Not applicable.
Sequence Field/Strength
Renal fast gradient echoâbased 2D PCâMRI.
Assessment
An international panel of 27 experts from Europe, the USA, Australia, and Japan with 6 (interquartile range 4â10) years of experience in 2D PCâMRI formulated consensus statements on renal 2D PCâMRI in two rounds of surveys. Starting from a recently published systematic review article, literatureâbased and dataâdriven statements regarding patient preparation, hardware, acquisition protocol, analysis steps, and data reporting were formulated.
Statistical Tests
Consensus was defined as âĽ75% unanimity in response, and a clear preference was defined as 60â74% agreement among the experts.
Results
Among 60 statements, 57 (95%) achieved consensus after the secondâround survey, while the remaining three showed a clear preference. Consensus statements resulted in specific recommendations for subject preparation, 2D renal PCâMRI data acquisition, processing, and reporting.
Data Conclusion
These recommendations might promote a widespread adoption of renal PCâMRI, and may help foster the setâup of multicenter studies aimed at defining reference values and building larger and more definitive evidence, and will facilitate clinical translation of PCâMRI.
Level of Evidence
1
Technical Efficacy Stage
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