Temporal trend in the transfer of Sellafield-derived 14C into different size fractions of the carbonate component of NE Irish Sea sediment

From 1994 onwards, 14C discharges from the Sellafield nuclear fuel reprocessing plant have been made largely to the Northeast Irish Sea. They represent the largest contributor to UK and European populations of the collective dose commitment derived from the entire nuclear industry discharges. Consequently, it is important to understand the long-term fate of 14C in the marine environment. Research undertaken in 2000 suggested that the carbonate component of Northeast Irish Sea sediments would increase in 14C activity as mollusc shells, which have become enriched in Sellafield-derived 14C, are broken down by physical processes including wave action and incorporated into intertidal and sub-tidal sediments. The current study, undertaken in 2011, tested this hypothesis. The results demonstrate significant increases in 14C enrichments found in whole mussel shells compared to those measured in 2000. Additionally, in 2000, there was an enrichment above ambient background within only the largest size fraction (>500 μm) of the intertidal inorganic sediment at Nethertown and Flimby (north of Sellafield). In comparison, the present study has demonstrated 14C enrichments above ambient background in most size fractions at sites up to 40 km north of Sellafield, confirming the hypothesis set out more than a decade ago

Detecting variable (V), diversity (D) and joining (J) gene segment recombination using a two-colour fluorescence system

<p>Abstract</p> <p>Background</p> <p>Diversity of immunoglobulins and the T cell antigen receptors is achieved via the recombination activating gene (RAG)-mediated rearrangement of variable (V), diversity (D) and joining (J) gene segments, and this underpins the efficient recognition of a seemingly limitless array of antigens. Analysis of V(D)J recombination activity is typically performed using extrachromosomal recombination substrates that are recovered from transfected cells and selected using bacterial transformation. We have developed a two-colour fluorescence-based system that simplifies detection of both deletion and inversion joining events mediated by RAG proteins.</p> <p>Results</p> <p>This system employs two fluorescent reporter genes that differentially mark unrearranged substrates and those that have undergone RAG-mediated deletion or inversion events. The recombination products bear the hallmarks of true V(D)J recombination and activity can be detected using fluorescence microscopy or flow cytometry. Recombination events can be detected without the need for cytotoxic selection of recombination products and the system allows analysis of recombination activity using substrates integrated into the genome.</p> <p>Conclusions</p> <p>This system will be useful in the analysis and exploitation of the V(D)J recombination machinery and suggests that similar approaches could be used to replace expression of one gene with another during lymphocyte development.</p

Interpreting forest and grassland biome productivity utilizing nested scales of image resolution and biogeographical analysis

Several hardware, software, and data collection problems encountered were conquered. The Geographic Information System (GIS) data from other systems were converted to ERDAS format for incorporation with the image data. Statistical analysis of the relationship between spectral values and productivity is being pursued. Several project sites, including Jackson, Pope, Boulder, Smokies, and Huntington Forest are evolving as the most intensively studied areas, primarily due to availability of data and time. Progress with data acquisition and quality checking, more details on experimental sites, and brief summarizations of research results and future plans are discussed. Material on personnel, collaborators, facilities, site background, and meetings and publications of the investigators are included

Resistant tissues of modern marchantioid liverworts resemble enigmatic Early Paleozoic microfossils

Absence of a substantial pretracheophyte fossil record for bryophytes (otherwise predicted by molecular systematics) poses a major problem in our understanding of earliest land-plant structure. In contrast, there exist enigmatic Cambrian–Devonian microfossils (aggregations of tubes or sheets of cells or possibly a combination of both) controversially interpreted as an extinct group of early land plants known as nematophytes. We used an innovative approach to explore these issues: comparison of tube and cell-sheet microfossils with experimentally degraded modern liverworts as analogues of ancient early land plants. Lower epidermal surface tissues, including rhizoids, of Marchantia polymorpha and Conocephalum conicum were resistant to breakdown after rotting for extended periods or high-temperature acid treatment (acetolysis), suggesting fossilization potential. Cell-sheet and rhizoid remains occurred separately or together depending on the degree of body degradation. Rhizoid break-off at the lower epidermal surface left rimmed pores at the centers of cell rosettes; these were similar in structure, diameter, and distribution to pores characterizing nematophyte cell-sheet microfossils known as Cosmochlaina. The range of Marchantia rhizoid diameters overlapped that of Cosmochlaina pores. Approximately 14% of dry biomass of Marchantia vegetative thalli and 40% of gametangiophores was resistant to acetolysis. Pre- and posttreatment cell-wall autofluorescence suggested the presence of phenolic compounds that likely protect lower epidermal tissues from soil microbe attack and provide dimensional stability to gametangiophores. Our results suggest that at least some microfossils identified as nematophytes may be the remains of early marchantioid liverworts similar in some ways to modern Marchantia and Conocephalum

DATASET2050 D4.1 - Current Supply Profile

The purpose of this document, Deliverable 4.1, is to describe the Current Supply Profile for its further use in different threads by the DATASET2050 Horizon 2020 coordination and support action. This deliverable comprises the work conducted in order to define and list the door-to-door mobility supply components, as described in task 4.1. It presents the baseline supply situation with respect to current door-to-door trips within Europe, including an assessment, identification and mode of the mobility services currently available in Europe (airport access/egress times, airport processes times etc.) All the above will allow the DATASET2050 project partners to determine the time required to undertake the current processes involved from leaving the place of origin (the "Door") to the point of arrival at the airport (the "Kerb"), from the Kerb to the moment the passenger has had their boarding card scanned immediately prior to embarkation (the "Gate"). The same approach is used for the Gate-to-Gate processes (including connecting flights and the transfer process), and finally Gate-to-Kerb and Kerb-to-Door. The inherent asymmetries of what are, in principle, symmetric processes have been assessed (e.g.: Door-to-Kerb vs. Kerb-to-Door). D4.1 directly feeds the supply side of the mobility model that will be run in WP5 of DATASET2050

DATASET2050 D4.2 - Future supply profile

The purpose of this document, Deliverable 4.2, is to describe the future supply profile of EU mobility in the context of air transport. This includes, but is not restricted to, the evolution of the different travel services detailed in earlier DATASET2050 tasks and their corresponding trade-offs. This deliverable and associated tasks feed the model quantitatively and qualitatively via WP5, representing a key milestone for the DATASET2050 model

Design study for a laminar-flying-wing aircraft

The Greener by Design initiative has identified the laminar-flying-wing configuration as the most promising long-term prospect for fuel-efficient civil aviation. However, in the absence of detailed evaluations, its potential remains uncertain. As an initial contribution, this work presents a point design study for a specification chosen to maximize aerodynamic efficiency, via large wingspan and low sweepback. The resulting aircraft carries 220 passengers over a range of 9000 km at Mach 0.67 and has a lift-to-drag ratio of 60.9, far in excess of conventional passenger transports. However, its overall effectiveness is compromised by a high empty-to-payload weight ratio and, because of the huge discrepancy between cruise and climb-out thrust requirements, a poor engine efficiency. As a result, it has a much less marked fuel-consumption advantage (11.4–13.9 g per passenger kilometer, compared to 14.6) over a conventional competitor designed, using the same methods, for the same mission. Both weight ratio and engine efficiency could be improved by reducing aspect ratio, but at the cost of an aerodynamic efficiency penalty. This conflict, which has not previously been recognized, is inherent to the laminar-flying-wing concept and may undermine its attractiveness.This paper has benefited from the perceptive comments made by its reviewers, especially with regard to the influence of altitude on engine efficiency. The first author thanks the Engineering and Physical Sciences Research Council for financial support via its Doctoral Training scheme. Supporting research data are available at https://www.repository.cam.ac.uk/handle/1810/247199/browse?type=title.This is the author accepted manuscript. The final version is available from American Institute of Aeronautics and Astronautics via http://dx.doi.org/10.2514/1.C03286

Resistant tissues of modern marchantioid liverworts resemble enigmatic Early Paleozoic microfossils

Absence of a substantial pretracheophyte fossil record for bryophytes (otherwise predicted by molecular systematics) poses a major problem in our understanding of earliest land-plant structure. In contrast, there exist enigmatic Cambrian–Devonian microfossils (aggregations of tubes or sheets of cells or possibly a combination of both) controversially interpreted as an extinct group of early land plants known as nematophytes. We used an innovative approach to explore these issues: comparison of tube and cell-sheet microfossils with experimentally degraded modern liverworts as analogues of ancient early land plants. Lower epidermal surface tissues, including rhizoids, of Marchantia polymorpha and Conocephalum conicum were resistant to breakdown after rotting for extended periods or high-temperature acid treatment (acetolysis), suggesting fossilization potential. Cell-sheet and rhizoid remains occurred separately or together depending on the degree of body degradation. Rhizoid break-off at the lower epidermal surface left rimmed pores at the centers of cell rosettes; these were similar in structure, diameter, and distribution to pores characterizing nematophyte cell-sheet microfossils known as Cosmochlaina. The range of Marchantia rhizoid diameters overlapped that of Cosmochlaina pores. Approximately 14% of dry biomass of Marchantia vegetative thalli and 40% of gametangiophores was resistant to acetolysis. Pre- and posttreatment cell-wall autofluorescence suggested the presence of phenolic compounds that likely protect lower epidermal tissues from soil microbe attack and provide dimensional stability to gametangiophores. Our results suggest that at least some microfossils identified as nematophytes may be the remains of early marchantioid liverworts similar in some ways to modern Marchantia and Conocephalum