Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C). Part 1. The Irish Sea

Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon (14C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14C dispersal and uptake dynamics. All east basin biota exhibited 14C enrichments above ambient background while most west basin biota had 14C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14C to the west basin and retention therein. Despite ongoing Sellafield 14C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14C-enriched organic material by organisms and mixing to depth of 14C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant

Shotgun ion mobility mass spectrometry sequencing of heparan sulfate saccharides

Despite evident regulatory roles of heparan sulfate (HS) saccharides in numerous biological processes, definitive information on the bioactive sequences of these polymers is lacking, with only a handful of natural structures sequenced to date. Here, we develop a “Shotgun” Ion Mobility Mass Spectrometry Sequencing (SIMMS2) method in which intact HS saccharides are dissociated in an ion mobility mass spectrometer and collision cross section values of fragments measured. Matching of data for intact and fragment ions against known values for 36 fully defined HS saccharide structures (from di- to decasaccharides) permits unambiguous sequence determination of validated standards and unknown natural saccharides, notably including variants with 3O-sulfate groups. SIMMS2 analysis of two fibroblast growth factor-inhibiting hexasaccharides identified from a HS oligosaccharide library screen demonstrates that the approach allows elucidation of structure-activity relationships. SIMMS2 thus overcomes the bottleneck for decoding the informational content of functional HS motifs which is crucial for their future biomedical exploitation

Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C) part 2 : the west of Scotland

Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C) were examined within the West of Scotland marine environment. The dissolved inorganic carbon component of seawater, enriched in14C, is transported to the West of Scotland where it is transferred through the marine food web. Benthic and pelagic biota with variable life-spans living in the North Channel and Clyde Sea show comparable14C activities. This suggests that mixing of14C within the Irish Sea results in a relatively constant northwards dispersal of activity. Benthic species in the Firth of Lorn have similar14C enrichments, demonstrating that Irish Sea residual water is the dominant source to this area. Measured14C activities in biota show some similarity to western Irish Sea activities, indicating that dispersion to the West of Scotland is significant with respect to the fate of Sellafield14C releases. Activities measured in commercially important species do not pose any significant radiological risk

Thoughts on opportunities in high-energy nuclear collisions

This document reflects thoughts on opportunities from high-energy nuclear collisions in the 2020s.Comment: 10 pages, pd

Thoughts on heavy-ion physics in the high luminosity era: the soft sector

This document summarizes thoughts on opportunities in the soft-QCD sector from high-energy nuclear collisions at high luminosities.Comment: 19 page

Modelling marine trophic transfer of radiocarbon (14C) from a nuclear facility

Sellafield marine discharges of 14C are the largest contributor to the global collective dose from the nuclear fuel industry. As such, it is important to understand the fate of these discharges beyond the limitations and scope of empirical analytical investigations for this highly mobile radioactive contaminant. Ecopath with Ecosim (EwE) is widely used to model anthropogenic impacts on ecosystems, such as fishing, although very few EwE studies have modelled the fate of bioavailable contaminants. This work presents, for the first time, a spatial-temporal 14C model utilising recent developments in EwE software to predict the ecological fate of anthropogenic 14C in the marine environment. The model predicted observed trends in 14C activities between different species and through time. It also provided evidence for the integration of Sellafield 14C in species at higher trophic levels through time

Detection of the temporal variation of the sun's cosmic ray shadow with the IceCube detector

We report on the observation of a deficit in the cosmic ray flux from the directions of the Moon and Sun with five years of data taken by the IceCube Neutrino Observatory. Between 2010 May and 2011 May the IceCube detector operated with 79 strings deployed in the glacial ice at the South Pole, and with 86 strings between 2011 May and 2015 May. A binned analysis is used to measure the relative deficit and significance of the cosmic ray shadows. Both the cosmic ray Moon and Sun shadows are detected with high statistical significance (> 10 sigma) for each year. The results for the Moon shadow are consistent with previous analyses and verify the stability of the IceCube detector over time. This work represents the first observation of the Sun shadow with the IceCube detector. We show that the cosmic ray shadow of the Sun varies with time. These results make it possible to study cosmic ray transport near the Sun with future data from IceCube

High density lipoprotein mediates anti-inflammatory transcriptional reprogramming of macrophages via the transcriptional repressor ATF3

High Density Lipoprotein (HDL) mediates reverse cholesterol transport and it is known to be protective against atherosclerosis. In addition, HDL has potent anti-inflammatory properties that may be critical for protection against other inflammatory diseases. The molecular mechanisms of how HDL can modulate inflammation, particularly in immune cells such as macrophages, remain poorly understood. Here we identify the transcriptional repressor ATF3, as an HDL-inducible target gene in macrophages that down-regulates the expression of Toll-like receptor (TLR)-induced pro-inflammatory cytokines. The protective effects of HDL against TLR-induced inflammation were fully dependent on ATF3 in vitro and in vivo. Our findings may explain the broad anti-inflammatory and metabolic actions of HDL and provide the basis for predicting the success of novel HDL-based therapies

Development and evaluation of the Measure of the International Learning Environment Status (MILES) in international higher education

The aim of this study was to develop and evaluate an instrument to assess international students' perceptions of the international learning environment called 'Measure of the International Learning Environment Status' (MILES). We based the development of the MILES on a solid theoretical framework from Moos by addressing three domains to measure the quality of the international learning environment, namely goal direction, relationships, and system change and system maintenance. We have designed and constructed the instrument in three steps. Firstly, we have collected items from relevant existing instruments and grouped them into the three domains via content analysis. Secondly, we applied a Delphi procedure involving international higher education experts from different stakeholder groups and from different cultural backgrounds to identify and reach consensus on the items comprehensively covering important elements of the international learning environment. Thirdly, we carried out an initial questionnaire evaluation. The final MILES consisted of 47 items with 13 in the first domain, 17 in the second and 17 in the third domain. The content of the domains was clearly in line with Moos theoretical framework and we interpreted the sets of items as goal direction, relationships, and supporting services, respectively. This study provides a comprehensive and systematically developed instrument for future research to better understand international students' perspectives towards the international learning environment that are supported by stakeholders from a range of cultures.</p