397 research outputs found
A re-interpretation of the internal structure of the Lizard complex ophiolite, south Cornwall.
publication-status: PublishedPrevious models for the tectonic-stratigraphy of the Lizard complex ophiolite have proposed three thrust-bounded units. However, our studies indicate that post-obduction extensional faulting may have exerted a hitherto unrecognised effect on the present distribution of lithologies. Field and previously published geophysical evidence suggest that the uppermost tectonic unit (the Crousa Downs Unit) represents the downfaulted upper levels of the Goonhilly Downs Unit. Deformed lithologies previously thought to be part of the Goonhilly Downs Unit are reassigned to the underlying Basal Unit. A revised model for the tectonic-stratigraphy is presented. The Basal Nappe is underlain by the Basal Thrust and comprises the Traboe schists, the Landewednack schists and the Old Lizard Head Series. The Goonhilly Downs Nappe, underlain by the Goonhilly Downs Thrust, structurally overlies the Basal Nappe and comprises serpentinised peridotite, Trelan and Crousa Gabbro and the Porthoustock Sheeted Dyke Complex. This work highlights the importance of late- to post-Variscan extensional deformation in south Cornwall
Alteration and vein mineralisation within the Lizard complex, south Cornwall: Constraints on the timing of serpentinisation.
Two distinct episodes of serpentinisation have been identified within the peridotites of the Lizard complex. The first episode (primary serpentinisation) is represented by the complex and pervasive hydration of the Lizard peridotite. The second (later) episode is characterised by a pale to dark green, pseudo-fibrous mixture of lizardite and chrysotile that is restricted to fractures (vein serpentine). Mineralised north-north-west and east-north-east trending fault zones contain fragments of vein serpentine generated during this second episode. Faults with similar orientations and mineralogy within the gabbro unit contain adularia which have been previously elated by Ar-10-Ar-39 and K-Ar methods at 210-220 Ma (Triassic). Stable isotope ratios indicate that the mineralisation within the gabbro and peridotite is genetically similar. The primary and secondary serpentinisation episodes are therefore interpreted as pre-Triassic in age. A latest Carboniferous to early Permian age is proposed for the formation of vein serpentine and a late Devonian to Carboniferous age is proposed for the primary serpentinisation episode. This is envisaged to have taken place post-obduction but a pre-obduction initiation of serpentinisation cannot be discounted
Identification of dermestid beetle modification on Neolithic Maltese human bone: Implications for funerary practices at the Xemxija tombs
Taphonomic modifications to Neolithic human skeletal remains from six rock-cut tombs in Malta has provided key information about funerary practices and the local environment. Application of microscopic analysis, computed tomography (CT) scanning, and 3D imaging of the modifications has allowed their comparison with similar examples in modern and archaeological skeletal material. The modifications are interpreted as pupal chambers and feeding damage by dermestid beetles. Based on observation of the behaviour and ecology of dermestid beetles, we suggest several scenarios for funerary practices at the Xemxija tombs which nuance our current understanding of collective burial during the late Neolithic in Malta.Magdalene College, Cambridg
Constraining the provenance of the Stonehenge 'Altar Stone': Evidence from automated mineralogy and UâPb zircon age dating
The Altar Stone at Stonehenge is a greenish sandstone thought to be of Late Silurian-Devonian (âOld Red Sandstoneâ) age. It is classed as one of the bluestone lithologies which are considered to be exotic to the Salisbury Plain environ, most of which are derived from the Mynydd Preseli, in west Wales. However, no Old Red Sandstone rocks crop out in the Preseli; instead a source in the Lower Old Red Sandstone Cosheston Subgroup at Mill Bay to the south of the Preseli, has been proposed. More recently, on the basis of detailed petrography, a source for the Altar Stone much further to the east, towards the Wales-England border, has been suggested. Quantitative analyses presented here compare mineralogical data from proposed Stonehenge Altar Stone debris with samples from Milford Haven at Mill Bay, as well as with a second sandstone type found at Stonehenge which is Lower Palaeozoic in age. The Altar Stone samples have contrasting modal mineralogies to the other two sandstone types, especially in relation to the percentages of its calcite, kaolinite and barite cements. Further differences between the Altar Stone sandstone and the Cosheston Subgroup sandstone are seen when their contained zircons are compared, showing differing morphologies and U-Pb age dates having contrasting populations. These data confirm that Mill Bay is not the source of the Altar Stone with the abundance of kaolinite in the Altar Stone sample suggesting a source further east, towards the Wales-England border. The disassociation of the Altar Stone and Milford Haven undermines the hypothesis that the bluestones, including the Altar Stone, were transported from west Wales by sea up the Bristol Channel and adds further credence to a totally land-based route, possibly along a natural routeway leading from west Wales to the Severn estuary and beyond. This route may well have been significant in prehistory, raising the possibility that the Altar Stone was added en route to the assemblage of Preseli bluestones taken to Stonehenge around or shortly before 3000 BC. Recent strontium isotope analysis of human and animal bones from Stonehenge, dating to the beginning of its first construction stage around 3000 BC, are consistent with the suggestion of connectivity between this western region of Britain and Salisbury Plain.This study appears to be the first application of quantitative automated mineralogy in the provenancing of archaeological lithic material and highlights the potential value of automated mineralogy in archaeological provenancing investigations, especially when combined with complementary techniques, in the present case zircon age dating
Monitoring Impacts of Urbanisation and Industrialisation on Air Quality in the Anthropocene Using Urban Pond Sediments
This is the final version of the article. Available from Frontiers Media via the DOI in this record.The release of toxic atmospheric pollutants since the Industrial Revolution is a major global challenge, driving climate change and damaging human health. Spatial health inequalities highlight the need to explore air pollution in different localities throughout the Anthropocene. Air quality monitoring programmes are spatially and temporally limited. We show how suitable urban sediment archives provide site specific records of long-term particulate matter (PM) releases, in cities and urban landscapes, that are or have been subjected to high pollution levels. High-resolution PM records spanning from the mid-20th century were reconstructed from an urban pond in Chongqing, southwest China, one of the fastest growing Chinese urban centres in the late 20th century. Temporal variations in pollution proxies including geomagnetic, geochemical and spheroidal carbonaceous particle trends correspond to key phases of industrial and urban developments, that are representative of the locality. Observed increases in air pollution proxies post-1960 coincide with the location of military-related industries to Chongqing and industrial intensification. Post-1997 pollution mirrors rapid urbanisation that occurred following the designation of Chongqing as a government-controlled municipality at this time and reveals a steadily increasing pollution trend to present day (2015). In comparison to Chongqing, an atmospheric depositional history was constructed from an urban pond in the Merseyside region of northwest England that has experienced a legacy of contamination since the early 19th century. In northwest England, changing characteristics of pollution are related to the establishment of localised, modern industries, power generation, urban sprawl, increased combustion-derived pollution post-1990 and effective pollution legislations. Whereas a reduction in air pollution has occurred post-2000 in Merseyside, in Chongqing, however, air pollution has continued to increase in spite of national efforts in pollution control. These urban sediments reveal the changing nature of air pollution in different urban landscapes, allowing us to assess air quality impacts of progressive industrial activity, increased road and air travel, urban expansion and the efficacy of pollution controls. It appears that air pollution remains an inevitable consequence of global industrialisation. It is therefore crucial to understand pollution histories in densely populated urban regions to determine environmental burdens of pollution on health over generational timescales.This research was supported by Halton Primary Care Trust (grant number CHCRD001 SE02), Edge Hill University (fund codes: RDWOR04, RDWOR05, RDWOR06, and RDWOR209), and the University of Exeter
A Hybrid Sequencing Approach Completes the Genome Sequence of Thermoanaerobacter ethanolicus JW 200
This is the final version. Available on open access from American Society for Microbiology via the DOI in this recordData availability.The complete genome sequence of T. ethanolicus JW 200 is deposited in GenBank under the accession number CP033580. Illumina and Oxford Nanopore DNA sequence reads have been deposited in the NCBI Sequence Read Archive (accession numbers SRR8113455 and SRR8113456).Thermoanaerobacter ethanolicus JW 200 has been identified as a potential sustainable biofuel producer due to its ability to readily ferment carbohydrates to ethanol. A hybrid sequencing approach, combining Oxford Nanopore and Illumina DNA sequence reads, was applied to produce a single contiguous genome sequence of 2,911,280âbp.Shell Research Ltd
In-situ sequencing reveals the effect of storage on lacustrine sediment microbiome demographics and functionality
This is the final version. Available from BMC via the DOI in this record.âŻAvailability of data and materials: The datasets generated and analysed during the current study are available in the NCBI SRA repository under BioProject ID PRJNA548524.The sediment microbiome is a demographically diverse and functionally active biosphere. Ensuring that data acquired
from sediment is truly representative of the microbiome is critical to achieving robust analyses. Sample storage
and the processing and timing of nucleic acid purification after environmental sample extraction may fundamentally affect the detectable microbial community and thereby significantly alter resultant data. Direct sequencing of
environmental samples is increasingly commonplace due to the advent of the portable Oxford Nanopore MinION
sequencing device. Here we demonstrate that storing sediment subsamples at â20 °C or storing the cores at 4 °C
for 10 weeks prior to analysis, has a significant effect on the sediment microbiome analysed using sedimentary DNA
(sedDNA), especially for Alpha-, Beta- and Deltaproteobacteria species. Furthermore, these significant differences are
observed regardless of sediment type. We show that the taxa which are predominantly affected by storage are Proteobacteria, and therefore recommend on-site purifications are performed to ensure an accurate representation of these
taxa are observed in the microbiome. Comparisons of sedimentary RNA (sedRNA) analyses, revealed substantial differences between samples purified and sequenced immediately on-site, samples that were frozen before transportation,
and cores that were stored at 4 °C prior to analysis. Our data therefore suggest that a more accurate representation of
the sediment microbiome demography and functionality may be achieved by environmental sequencing as rapidly
as possible to minimise confounding effects of storage.University of Exete
Mobilizing management knowledge in healthcare : institutional imperatives and professional and organizational mediating effects
Recent changes within UK healthcare have had dramatic consequences for management and put managerial capabilities firmly under the spotlight. Yet, despite extensive research on managers, comparatively little is known about how they acquire and apply their management knowledge and how this is influenced by their professional background and organizational context. Drawing upon work that distinguishes between different forms of knowledge, managersâ mobilization of management knowledge is examined in the light of recent changes in healthcare. Case study evidence is presented from diverse managerial groups across three types of hospital trust (acute, care and specialist). The analysis demonstrates the mediating effects of interactions between professional background and organizational context on knowledge mobilization and highlights how current pressures on public services are reinforcing a reliance on existing management practices, creating enormous challenges for management learning in this sector
Bacterial dormancy: a subpopulation of viable but non-culturable cells demonstrates better fitness for revival
This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: The data is all found in this manuscript.The viable but non culturable (VBNC) state is a condition in which bacterial cells are viable and metabolically active, but resistant to cultivation using a routine growth medium. We investigated the ability of V. parahaemolyticus to form VBNC cells, and to subsequently become resuscitated. The ability to control VBNC cell formation in the laboratory allowed us to selectively isolate VBNC cells using fluorescence activated cell sorting, and to differentiate subpopulations based on their metabolic activity, cell shape and the ability to cause disease in Galleria mellonella. Our results showed that two subpopulations (P1 and P2) of V. parahaemolyticus VBNC cells exist and can remain dormant in the VBNC state for long periods. VBNC subpopulation P2, had a better fitness for survival under stressful conditions and showed 100% revival under favourable conditions. Proteomic analysis of these subpopulations (at two different time points: 12 days (T12) and 50 days (T50) post VBNC) revealed that the proteome of P2 was more similar to that of the starting microcosm culture (T0) than the proteome of P1. Proteins that were significantly up or down-regulated between the different VBNC populations were identified and differentially regulated proteins were assigned into 23 functional groups, the majority being assigned to metabolism functional categories. A lactate dehydrogenase (lldD) protein, responsible for converting lactate to pyruvate, was significantly upregulated in all subpopulations of VBNC cells. Deletion of the lactate dehydrogenase (RIMD2210633:lldD) gene caused cells to enter the VBNC state significantly more quickly compared to the wild-type, and adding lactate to VBNC cells aided their resuscitation and extended the resuscitation window. Addition of pyruvate to the RIMD2210633:lldD strain restored the wild-type VBNC formation profile. This study suggests that lactate dehydrogenase may play a role in regulating the VBNC stateLyons Seafoods LimitedBiotechnology & Biological Sciences Research Council (BBSRC
A systems approach to policy evaluation
There is growing interest in evaluating policy implementation in ways that grapple with the complexity of the process. This article offers an example of using systems methodology to explore how the child protection policy in child contact centres has functioned in practice. Rather than just asking the traditional evaluation question âis it working?â this study sought to understand how the policy was working and how it was interpreted as it interacted with other systems, producing conflicts, local variation and emergent effects. It illustrates how the systems concepts of âemergenceâ, âlocal rationalityâ, âsocio-technical systemsâ and âfeedback for learningâ can contribute new knowledge and understanding to a complex policy evaluation problem
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