Peat’s secret archive: Interpreting the geochemical and palaeodust record from Scottish peat as a potential index of North Atlantic storminess and Holocene climate change

Four continuous high-resolution peat records for the Holocene have been reconstructed across a ~300km transect from Shebster in Caithness to Yell in the Shetland Isles. These records describe the nature and extent of North Atlantic climate changes inferred from indicators of storminess and minerogenic aeolian dust, and are supported by radiogenic isotope analysis, tephrochronology and radiocarbon dating. The environmental changes at all four sites displays a significant degree of synchrony in response to changes in the position of the polar front jet (PFJ) stream and the phase of the North Atlantic Oscillation (NAO). Bromine concentrations in the peat, derived from sea spray, are used to reconstruct storm frequency and storm intensity, and mire surface wetness is used as an indicator of longer-term climate shifts. The results suggest a strong link between positive phases of the NAO and storminess. Subtle differences between the bromine concentrations and the mire surface wetness suggest that high intensity but perhaps less frequent periods of storminess are not necessarily associated with a wetter climate. Atmospheric minerogenic dust concentrations are used to reconstruct large-scale climate changes across the wider North Atlantic region. The results suggest a sympathy between dust activity and periods of glacial advance and a negative index of the NAO. Radiogenic isotope analysis suggests that the smallest particles may originate from Iceland

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

JNCC Offshore Natura Survey : Anton Dohrn Seamount and East Rockall Bank areas of search : 2009/03-JNCC Cruise Report

This cruise report summarises operations and initial observations onboard the M/V Franklin during cruise 2009/03-JNCC on behalf of the Joint Nature Conservation Committee (JNCC). The cruise took place between the 1st and 29th of July 2009 and surveyed two Areas of Search (AoS) for offshore Special Areas of Conservation (SACs): Anton Dohrn Seamount located 155km west of the St Kilda archipelago, and East Rockall Bank located 260km west of the St Kilda archipelago (Figure 1). The main aims of the survey were to acquire acoustic and photographic “ground-truthing” data to enable geological, geomorphological and biological characterisation of the Anton Dohrn Seamount and East Rockall Bank AoS. Specifically, the data acquired will lead to the production of broadscale habitat maps, the identification and description of Annex I reef habitats with particular attention to the occurrence of bedrock, stony and biogenic reef, to identify and record any anthropogenic impacts in the areas of search and finally to evaluate data acquisition methods, techniques and equipment. The work programme was highly successful with 215 line kilometres of multibeam echosounder and 10 photographic “ground-truthing” sites acquired in the Anton Dohrn Seamount AoS, and 692 line kilometres of multibeam echosounder and 168 line kilometres of sidescan sonar data and 17 photographic “ground-truthing” sites acquired in the East Rockall Bank AoS. No physical sea-bed samples were acquired during this cruise. The data revealed the flanks and area immediately adjacent to Anton Dohrn Seamount to comprise predominantly gravel-rich sediment with bedrock outcropping on the steeper sections of the Seamount flanks. East Rockall Bank comprised predominantly gravelly muddy sand on the eastern flank of the Bank with gravel- and sand-rich sediments dominating the crest of the Bank. Interestingly, the parasitic cones surveyed within the Anton Dohrn area of search comprised predominantly corals, including large gorgonian species, small bamboo coral, the soft coral Anthomastus sp. and the antipatharian Leiopathes sp. Significant bedrock reef was encountered during the course of this cruise along an escarpment located on the eastern flank of Rockall Bank roughly coincident with the 500m bathymetric contour. This laterally extensive feature primarily comprises volcanic bedrock with possible sedimentary bedrock cropping out at sea bed colonised by large stylsaterid hydrocorals and sponges. Preliminary observations and interpretation of the data acquired during the course of this cruise suggest that several sites may fit the definition of Annex I reef under the EC Habitats Directive. If they fulfil the criteria for Annex I reef, they will be assessed against site selection criteria as possible areas for consideration as SACs

Repetitive mild traumatic brain injury in a mouse model produces learning and memory deficits accompanied by histological changes

Concussion or mild traumatic brain injury (mTBI) represents the most common type of brain injury. However, in contrast with moderate or severe injury, there are currently few non-invasive experimental studies that investigate the cumulative effects of repetitive mTBI using rodent models. Here we describe and compare the behavioral and pathological consequences in a mouse model of single (s-mTBI) or repetitive injury (r-mTBI, five injuries given at 48 h intervals) administered by an electromagnetic controlled impactor. Our results reveal that a single mTBI is associated with transient motor and cognitive deficits as demonstrated by rotarod and the Barnes Maze respectively, whereas r-mTBI results in more significant deficits in both paradigms. Histology revealed no overt cell loss in the hippocampus, although a reactive gliosis did emerge in hippocampal sector CA1 and in the deeper cortical layers beneath the injury site in repetitively injured animals, where evidence of focal injury also was observed in the brainstem and cerebellum. Axonal injury, manifest as amyloid precursor protein immunoreactive axonal profiles, was present in the corpus callosum of both injury groups, though more evident in the r-mTBI animals. Our data demonstrate that this mouse model of mTBI is reproducible, simple, and noninvasive, with behavioral impairment after a single injury and increasing deficits after multiple injuries accompanied by increased focal and diffuse pathology. As such, this model may serve as a suitable platform with which to explore repetitive mTBI relevant to human brain injury

The immune response in a dog to Encephalitozoon cuniculi infection

The immune response to Encephalitozoon cuniculi infection in a dog was investigated by means of the indirect fluorescent antibody test, the leucocyte migration inhibition test and the radial immunodiffusion test for serum IgG and IgM levels. Specific antibodies were detected within 7 days of infection and they persisted for 370 days. A cellmediated immune response was detected from Day 13 following infection until Day 97. Histopathological examination showed plasma cell infiltration of the kidneys, meninges, lung, bladder, smooth muscle and spleen.The immune response to Encephalitozoon cuniculi infection in a dog was investigated by means of the indirect fluorescent antibody test, the leucocyte migration inhibition test and the radial immunodiffusion test for serum IgG and IgM levels. Specific antibodies were detected within 7 days of infection and they persisted for 370 days. A cell-mediated immune response was detected from Day 13 following infection until Day 97. Histopathological examination showed plasma cell infiltration of the kidneys, meninges, lung, bladder, smooth muscle and spleen.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.University of Pretoria.mn201

Selective superoxide generation within mitochondria by the targeted redox cycler MitoParaquat

Superoxide is the proximal reactive oxygen species (ROS) produced by the mitochondrial respiratory chain and plays a major role in pathological oxidative stress and redox signaling. While there are tools to detect or decrease mitochondrial superoxide, none can rapidly and specifically increase superoxide production within the mitochondrial matrix. This lack impedes progress, making it challenging to assess accurately the roles of mitochondrial superoxide in cells and in vivo. To address this unmet need, we synthesized and characterized a mitochondria-targeted redox cycler, MitoParaquat (MitoPQ) that comprises a triphenylphosphonium lipophilic cation conjugated to the redox cycler paraquat. MitoPQ accumulates selectively in the mitochondrial matrix driven by the membrane potential. Within the matrix, MitoPQ produces superoxide by redox cycling at the flavin site of complex I, selectively increasing superoxide production within mitochondria. MitoPQ increased mitochondrial superoxide in isolated mitochondria and cells in culture ~a thousand-fold more effectively than untargeted paraquat. MitoPQ was also more toxic than paraquat in the isolated perfused heart and in Drosophila in vivo. MitoPQ enables the selective generation of superoxide within mitochondria and is a useful tool to investigate the many roles of mitochondrial superoxide in pathology and redox signaling in cells and in vivo

8000 years of North Atlantic storminess reconstructed from a Scottish peat record: implications for Holocene atmospheric circulation patterns in Western Europe

North Atlantic storminess can affect human settlements, infrastructure and transport links, all of which strongly impact local, national and global economies. An increase in storm frequency and intensity is predicted over the Northeast Atlantic in the 21st century because of a northward shift in storm tracks and a persistently positive North Atlantic Oscillation (NAO), driven by recent atmospheric warming. Although documentary records of North Atlantic storminess exist, these are generally limited to the last c. 1000‐2000 years. This paper presents a continuous high‐resolution proxy record of storminess spanning the last 8000 years from a 6 m long core taken from a peat bog in Northern Scotland. Bromine concentrations in the peat, derived from sea spray, are used to reconstruct storm frequency and storm intensity, and mire surface wetness is used as an indicator of longer‐term climate shifts. The results suggest a relationship between positive phases of the NAO and increased North Atlantic storminess. However, subtle differences between bromine concentrations and mire surface wetness suggest that high intensity but perhaps less frequent periods of storminess are not necessarily associated with a wetter climate

Options for managing alkaline steel slag leachate: A life cycle assessment

Management of steel slag (a major by-product of the steel industry) includes the treatment of highly alkaline leachate (pH > 11.5) from rainwater infiltration of slag deposits to prevent adverse impact upon surface or ground waters. This study aims to compare different treatment options for steel slag leachate through a life cycle assessment (LCA). Five options were compared: active treatment by acid dosing (A-H2SO4), active treatment by carbon dioxide dosing (A-CO2), active treatment by calcium chloride dosing (A-CaCl2), passive treatment by cascade and reedbeds with pumping (P-P), and passive treatment by cascade and reedbeds in a gravity-driven configuration (P-G). The functional unit was 1 m3 of treated leachate with pH < 9, considering 24 h and 365 days of operating, maintenance operations every year, and service life of 20 years. Inventory data were obtained from project designers, commercial suppliers, laboratory data and field tests. The environmental impacts were calculated in OpenLCA using the ELCD database and ILCD 2011 method, covering twelve impact categories. The A-CaCl2 option scored worse than all other treatments for all considered environmental impact categories. Regarding human toxicity, A-CaCl2 impact was 1260 times higher than the lowest impact option (A-CO2) for carcinogenics and 53 times higher for non-carcinogenics (A-H2SO4). For climate change, the lowest impact was calculated for P-G < P-P < A-H2SO4 < A-CO2 < A-CaCl2, while for particulate matter/respiratory inorganics, the options ranked as follows P-G < P-P < A-CO2 < A-H2SO4 < A-CaCl2. The major contributor to these impact categories was the Solvay process to produce CaCl2. Higher uncertainty was associated with the categories particulate matter formation, climate change and human toxicity, as they are driven by indirect emissions from electricity and chemicals production. Both passive treatment options had better environmental performance than the active treatment options. Potential design measures to enhance environmental performance of the treatments regarding metal removal and recovery are discussed and could inform operational management at active and legacy steel slag disposal sites

Taxonomy, phylogeny, and biodiversity of Lumbrineridae (Annelida, Polychaeta) from the Central Pacific Clarion-Clipperton Zone

The DNA taxonomy of six species of the annelid family Lumbrineridae collected from the Clarion-Clipperton Zone (CCZ) in the Central Pacific, an area of potential mining interest for polymetallic nodules, is presented. Lumbrinerids are an ecologically important and understudied annelid family within the deep sea, with many species still undescribed. This study aims to document the taxonomy and biodiversity of the CCZ using specimens collected from the UK-1, OMS, and NORI-D exploration contract areas and Areas of Particular Environmental Interest. Species were identified through a combination of morphological and molecular phylogenetic analysis. We present informal species descriptions associated with voucher specimens, accessible through the Natural History Museum (London) collections, to improve future taxonomic and biodiversity studies of this region. Five taxa in this study had no morphological or genetic matches within the literature and therefore are possibly new to science, but their suboptimal morphological preservation prevented the formalisation of new species. The most abundant taxon Lumbrinerides cf. laubieri (NHM_0020) was compared with the holotype of Lumbrinerides laubieri Miura, 1980 from the deep Northeast Atlantic. Currently no reliable morphological characters separating the Pacific and Atlantic specimens have been found and molecular data from the Atlantic specimens was not available.publishedVersio