The stratigraphy, correlation, provenance and palaeogeography of the Skiddaw Group (Ordovician) in the English Lake District

A new lithostratigraphy is presented for the Skiddaw Group (lower Ordovician) of the English Lake District. Two stratigraphical belts are described. Five formations are defined in the Northern Fells Belt, ranging in age from Tremadoc to early Llanvirn. They are all mudstone or sandstone dominated, of turbidite origin; in ascending order they are named the Bitter Beck, Watch Hill, Hope Beck, Loweswater and Kirk Stile formations. Two formations are defined in the Central Fells Belt, ranging in age from late Arenig to Llanvirn. These are the Buttermere Formation - a major olistostrome deposit - overlain by the Tarn Moor Formation, consisting of turbidite mudstones with volcaniclastic turbidite sandstone beds. A revised graptolite and new acritarch biostratigraphy for the Skiddaw Group is presented with eight graptolite biozones and thirteen acritarch assemblages and sub-assemblages. The provenance of the group is assessed from detailed petrographical and geochemical work. This suggests derivation, in the early Ordovician, largely from an old inactive continental arc terrane lying to the south-east, with the appearance of juvenile volcanic material in the Llanvirn. Comparisons and correlations of the Skiddaw Group are made with the Isle of Man and eastern Ireland

Linking anthropogenic resources to wildlife-pathogen dynamics: a review and meta-analysis

Urbanisation and agriculture cause declines for many wildlife, but some species benefit from novelresources, especially food, provided in human-dominated habitats. Resulting shifts in wildlife ecol-ogy can alter infectious disease dynamics and create opportunities for cross-species transmission,yet predicting host–pathogen responses to resource provisioning is challenging. Factors enhancingtransmission, such as increased aggregation, could be offset by better host immunity due toimproved nutrition. Here, we conduct a review and meta-analysis to show that food provisioningresults in highly heterogeneous infection outcomes that depend on pathogen type and anthropo-genic food source. We also find empirical support for behavioural and immune mechanismsthrough which human-provided resources alter host exposure and tolerance to pathogens. Areview of recent theoretical models of resource provisioning and infection dynamics shows thatchanges in host contact rates and immunity produce strong non-linear responses in pathogen inva-sion and prevalence. By integrating results of our meta-analysis back into a theoretical frame-work, we find provisioning amplifies pathogen invasion under increased host aggregation andtolerance, but reduces transmission if provisioned food decreases dietary exposure to parasites.These results carry implications for wildlife disease management and highlight areas for futurework, such as how resource shifts might affect virulence evolution

How to get started with a systematic review in epidemiology: an introductory guide for early career researchers

Background: systematic review is a powerful research tool which aims to identify and synthesize all evidence relevant to a research question. The approach taken is much like that used in a scientific experiment, with high priority given to the transparency and reproducibility of the methods used and to handling all evidence in a consistent manner.Early career researchers may find themselves in a position where they decide to undertake a systematic review, for example it may form part or all of a PhD thesis. Those with no prior experience of systematic review may need considerable support and direction getting started with such a project. Here we set out in simple terms how to get started with a systematic review.Discussion: advice is given on matters such as developing a review protocol, searching using databases and other methods, data extraction, risk of bias assessment and data synthesis including meta-analysis. Signposts to further information and useful resources are also given.Conclusion: a well-conducted systematic review benefits the scientific field by providing a summary of existing evidence and highlighting unanswered questions. For the individual, undertaking a systematic review is also a great opportunity to improve skills in critical appraisal and in synthesising evidence

DTI Strategic Environmental Assessment Area 4 (SEA4) : sub seabed geology

The SEA 4 region is underlain by continental crust situated on the north-western part of the Eurasian tectonic plate. The oldest continental crust >590Ma (Pre-Cambrian) of interest to oil production, it is divided by a major fault, the Moine Thrust, into ages ranging in age from >2500Ma (Archaean) to the west in which potentially commercial hydrocarbons been discovered and 2500 - 590 Ma (Proterozoic) to the east which is not currently prospective for commerciallyproduced hydrocarbons. The <590Ma sedimentary basins and intervening highs have evolved from pre-, syn- and postdepositional responses to deformation during crustal compression and extension. Many of the modern regional crustal structures retain a NE-SW trend, inherited from events 440-410Ma year ago (Caledonian Orogeny). The results from <65Ma regional NW-SE trending deformation events are also included within the major basin structural configurations. During 60-50 Ma (Late Paleocene to Early Eocene) the region was affected by uplift and in the NW by extrusion of thick volcanic lavas and intrusion of igneous sills. Interactions between historically significant shifts of long-term global climate cooling, an increase in the short-term periodicity and intensity of global climate change and changes to the rates and orientation of crust deformation have been particularly important from 25Ma to the present day (Neogene to Quaternary). These interactions have driven global-to-local changes to basin geological structure, marine circulation, sea level and sediment supply and removal rates and have resulted in the evolutionary changes to submarine basin geometries and lithologies. The modern seabed habitat has thus resulted from the remoulding of inherited basin geometries and lithologies by the processes affecting seabed. The structural history of the region has created a wide variety of potential hydrocarbon trapping mechanisms. The 154-136Ma (Late Jurassic, Kimmeridgian to Ryazanian) Kimmeridge Clay Formation is the principal source rock of the area. The Foinaven and Schiehallion oilfields started production in late 1997 and 1998 respectively both from 60-55Ma (Upper Paleocene) sandstone reservoirs. Geological and technical problems have so far prevented the development of the massive 440-390Ma (Devono-Carboniferous) Clair Field which is the largest undeveloped oilfield on the UK continental shelf. Other hydrocarbon accumulations have been discovered in 245-208Ma (Triassic), 208-146Ma (Jurassic) and 146-65Ma (Cretaceous) intervals in the West Shetland area in the most prospective parts of the SEA 4 region

Reprocessing of CHP datasets (HI 1567 & 1570) and seafloor substrate interpretation for selected areas : Inner Sound off Skye on the west coast of Scotland

This report describes the methodology for the processing of multibeam echosounder bathymetry, production of multibeam echosounder layers (bathymetry, hillshade, slope, aspect and rugosity) for display and interpretative purposes. Furthermore, an overview of the sea-bed substrate interpretation undertaken by the British Geological Survey (BGS) for three selected areas within Inner Sound off Skye on the west coast of Scotland is provided

Study of the dependence of 198Au half-life on source geometry

We report the results of an experiment to determine whether the half-life of \Au{198} depends on the shape of the source. This study was motivated by recent suggestions that nuclear decay rates may be affected by solar activity, perhaps arising from solar neutrinos. If this were the case then the $\beta$-decay rates, or half-lives, of a thin foil sample and a spherical sample of gold of the same mass and activity could be different. We find for \Au{198}, $(T_{1/2})_{\rm foil}/(T_{1/2})_{\rm sphere} = 0.999 \pm 0.002$, where $T_{1/2}$ is the mean half-life. The maximum neutrino flux at the sample in our experiments was several times greater than the flux of solar neutrinos at the surface of the Earth. We show that this increase in flux leads to a significant improvement in the limits that can be inferred on a possible solar contribution to nuclear decays.Comment: 5 pages, 1 figur

Uncertainty in mapped geological boundaries held by a national geological survey: eliciting the geologists' tacit error model

It is generally accepted that geological line work, such as mapped boundaries, are uncertain for various reasons. It is difficult to quantify this uncertainty directly, because the investigation of error in a boundary at a single location may be costly and time consuming, and many such observations are needed to estimate an uncertainty model with confidence. However, it is recognized across many disciplines that experts generally have a tacit model of the uncertainty of information that they produce (interpretations, diagnoses, etc.) and formal methods exist to extract this model in usable form by elicitation. In this paper we report a trial in which uncertainty models for geological boundaries mapped by geologists of the British Geological Survey (BGS) in six geological scenarios were elicited from a group of five experienced BGS geologists. In five cases a consensus distribution was obtained, which reflected both the initial individually elicited distribution and a structured process of group discussion in which individuals revised their opinions. In a sixth case a consensus was not reached. This concerned a boundary between superficial deposits where the geometry of the contact is hard to visualize. The trial showed that the geologists' tacit model of uncertainty in mapped boundaries reflects factors in addition to the cartographic error usually treated by buffering line work or in written guidance on its application. It suggests that further application of elicitation, to scenarios at an appropriate level of generalization, could be useful to provide working error models for the application and interpretation of line work

Statistical Model of Superconductivity in a 2D Binary Boson-Fermion Mixture

A two-dimensional (2D) assembly of noninteracting, temperature-dependent, composite-boson Cooper pairs (CPs) in chemical and thermal equilibrium with unpaired fermions is examined in a binary boson-fermion statistical model as the superconducting singularity temperature is approached from above. The model is derived from {\it first principles} for the BCS model interfermion interaction from three extrema of the system Helmholtz free energy (subject to constant pairable-fermion number) with respect to: a) the pairable-fermion distribution function; b) the number of excited (bosonic) CPs, i.e., with nonzero total momenta--usually ignored in BCS theory--and with the appropriate (linear, as opposed to quadratic) dispersion relation that arises from the Fermi sea; and c) the number of CPs with zero total momenta. Compared with the BCS theory condensate, higher singularity temperatures for the Bose-Einstein condensate are obtained in the binary boson-fermion mixture model which are in rough agreement with empirical critical temperatures for quasi-2D superconductorsComment: 16 pages and 4 figures. This is a improved versio

Seabed characterization: developing fit for purpose methodologies

We briefly describe three methods of seabed characterization which are ‘fit for purpose’, in that each approach is well suited to distinct objectives e.g. characterizing glacial geomorphology and shallow glacial geology vs. rapid prediction of seabed sediment distribution via geostatistics. The methods vary from manual ‘expert’ interpretation to increasingly automated and mathematically based models, each with their own attributes and limitations. We would note however that increasing automation and mathematical sophistication does not necessarily equate to improve map outputs, or reduce the time required to produce them. Judgements must be made to select methodologies which are most appropriate to the variables mapped, and according to the extent and presentation scale of final maps