Sediment suspended by bottom trawling can reduce reproductive success in a broadcast spawning fish

Suspended sediment adheres to pelagic fish eggs, affecting their buoyancy. In the stratified southern Baltic Sea, eggs of the Eastern cod depend on neutral buoyancy in the "reproductive volume" (RV) (approx. >11 salinity and >2 ml O2/L) for successful hatching. With increased suspended sediment concentrations (SSC), eggs risk sinking out of the RV into deeper, unfavourable conditions. Bottom trawling, which increases SSC, has been intense around the Eastern cod spawning ground. We modelled the transport of sediment suspended from trawling at this spawning ground to estimate the degree to which eggs could be affected by increased SSC. SSC >1 mg/L above background levels was found 3 km away, one trawl track subjecting a water volume equivalent to 0.01% of the RV to this excess SSC for >12 h. At this excess SSC, it would take c. 6 d for an egg to sink out into unfavourable conditions; insufficient time for it to become a larva. Extrapolating to real bottom trawling intensities in the area of the RV where suspension is highest showed that a water volume equivalent to half the RV experiences excess turbidity of >1 mg/L for c. 24 h during a year. However, fishing effort is heterogeneous; spatio-temporal overlap between trawling and the RV will enhance the duration and/or frequency of turbidity in the spawning area, affecting a higher fraction of the eggs than the model predicts. We conclude that bottom trawling at this spawning ground could decrease cod's reproductive success through increased SSC. Such effects are likely in populations of other fish with pelagic eggs that spawn at trawling grounds

Autocrine and paracrine growth mechanisms in human B lymphocytes

The SMS-SB cell line is an acute lymphoblastic leukaemia cell line with pre-B lymphocyte-like characteristics. Once removed from the patient, the cells could be grown in the absence of all exogenous mitogens, and were density-dependent for growth thus demonstrating the synthesis and secretion of an autocrine growth factor. Previous studies have found that this autocrine factor (SB-AF) can rescue SMS-SB cells from death, but have not been able to identify a cytokine able to substitute for its activity. The original aim of this thesis was to identify and characterise SB-AF and determine its anti-apoptotic mechanism. SB-AF was found to sustain the expression levels of the anti-apoptotic protein Bcl-2 and promote cell cycle progression. In addition, SB-AF seems to be a multi-component factor, whose anti-apoptotic activity results from the synergistic action of all its components. During these investigations, SMS-SB cells were found to express high levels of Bcl-2, which is unusual for lymphocytes at the pre-B developmental stage. In addition to the autocrine factor, previous work has demonstrated that soluble CD23 (sCD23) can act in a paracrine fashion to rescue low cell density cultures of SMS-SB cells from apoptotic death. This pleiotropic cytokine is a cleavage product of the 45kDa type II transmembrane CD23 antigen. As SMS-SB cells do not express the known receptors for CD23, namely, CD21, CD11b, and CD11c, the anti-apoptotic signals of sCD23 are mediated by a novel CD23 receptor. The work in this thesis shows that unlike sCD23, 45kDa membrane-associated CD23 does not seem to elicit the same response in SMS-SB cells, thus suggesting that only the soluble forms of CD23 can mediate anti-apoptotic effects via the novel receptor. However, the monolayer cell system used to present 45kDa CD23 appeared to be affecting SMS-SB cultures possibly influencing their response to CD23. Investigations were also undertaken to determine whether the novel receptor for CD23 was unique to the SMS-SB cell line. Preliminary data obtained from BIAcore surface plasmon resonance technology, demonstrate that the leukaemic pre-B cell lines Blin-1 and Nalm-6, and the mature B cell line 1E8, are able to bind sCD23 in the absence of the known CD23 receptors. Therefore, in addition to SMS-SB these cell lines also express a novel CD23 receptor. Further studies are required to determine whether all the cell lines express the same molecular receptor species, and whether signalling via these receptor(s) can prevent the apoptosis of Blin-1, Nalm-6 and 1E8 cells. The discovery of a novel CD23 binding receptor on a mature B cell line implies that, in addition to potentially having a role in precursor B cell development, sCD23 may also influence the growth and survival of more mature cell types away from the bone marrow microenvironment. It will therefore be interesting to investigate the role of CD23, and its novel receptor, throughout all stages of B cell development, and ultimately in all haematopoietic cells

A sprinkling of gold dust : Pine pollen as a carbon source in Baltic Sea coastal food webs

Allochthonous subsidies to marine ecosystems have mainly focused on biogeochemical cycles, but there has also been recent interest in how terrestrial carbon (C) influences marine food webs. In the Baltic Sea, pine (Pinus sylvestris) pollen is found in large amounts in shallow bays in early summer. Pollen is a significant C-source in freshwater ecosystems and may also be important in coastal food webs. We examined the consumption of pollen and autochthonous resources by benthic invertebrates in shallow bays of the Baltic Sea. We used stable isotopes to estimate diets and reconstructed consumer-resource networks (food webs) for grazers and particulate organic matter (POM)-feeders to compare how these different guilds used pollen. We found that P. sylvestris pollen was consumed in small amounts by a variety of animals and in some cases made up a sizeable proportion of invertebrates' diets. However, invertebrates generally depended less on pollen than other resources. The degree of pollen consumption was related to feeding traits, with generalist invertebrate grazers consuming more pollen (> 10% of diet) than the more specialist POM-feeders (< 5% of diet contributed by pollen). POM-feeders may consume additional microbially-degraded pollen which was not identifiable in our model. We suggest that pollen is a small but substantial allochthonous C-source in shallow bay food webs of the Baltic Sea, with the potential to affect the dynamics of these ecosystems.Peer reviewe

Education and training in radioecology during the EU-COMET project-successes and suggestions for the future

The 2014 Strategic Research Agenda (SRA) for Radioecology identified the key challenge in education and training (E&T) as being 'to maintain and develop a skilled workforce in Europe and world-wide, through university candidates and professionals trained within radioecology' since 'scientific research in radioecology and application of that knowledge ... requires scientists and workers with adequate competence and appropriate skills.' Radioecology is a multidisciplinary science and E&T is needed by both students and professionals within research, industry and radiation protection. In order to address these needs, the EU COMET project has developed an E&T web platform and arranged a number of field courses, training courses, PhD and MSc courses, refresher courses and workshops, drawing on the COMET consortium to assemble relevant experts. In addition, COMET has been engaged in discussions with stakeholders for more long-term solutions to maintain the sustainability of radioecology E&T after the end of the project. Despite much progress in some areas, many of the challenges outlined in the 2014 SRA remain, mainly due to the lack of sustainable dedicated funding. Future plans within the ALLIANCE radioecology platform and the CONCERT-European Joint Programme for the Integration of Radiation Protection Research must urgently address this lack of sustainability if radioecological competence is to be maintained in Europe

Characteristics and homogeneity of N6-methylation in human genomes.

A novel DNA modification, N-6 methylated deoxyadenosine (m6dA), has recently been discovered in eukaryotic genomes. Despite its low abundance in eukaryotes, m6dA is implicated in human diseases such as cancer. It is therefore important to precisely identify and characterize m6dA in the human genome. Here, we identify m6dA sites at nucleotide level, in different human cells, genome wide. We compare m6dA features between distinct human cells and identify m6dA characteristics in human genomes. Our data demonstrates for the first time that despite low m6dA abundance, the m6dA mark does often occur consistently at the same genomic location within a given human cell type, demonstrating m6dA homogeneity. We further show, for the first time, higher levels of m6dA homogeneity within one chromosome. Most m6dA are found on a single chromosome from a diploid sample, suggesting inheritance. Our transcriptome analysis not only indicates that human genes with m6dA are associated with higher RNA transcript levels but identifies allele-specific gene transcripts showing haplotype-specific m6dA methylation, which are implicated in different biological functions. Our analyses demonstrate the precision and consistency by which the m6dA mark occurs within the human genome, suggesting that m6dA marks are precisely inherited in humans

Evaluation of the Reforms to Summary Criminal Legal Assistance and Disclosure

This report presents the findings of an evaluation of the changes to disclosure and summary criminal legal assistance (SCLA)1 introduced under Summary Justice Reform (SJR). The overall aim of SJR is the establishment of a summary justice system which is: fair to the accused, victims and witnesses; effective in deterring and punishing offenders; efficient in the use of time and resources; and quick and simple in delivery