The ecohydrology and conservation of a coastal sedimentary lake and wetland system: Sheskinmore Lough, Donegal, Ireland

Lowland, shallow, coastal lake systems often comprise a complex array of habitats and species as a consequence of their geomorphic evolution, in combination with marine and terrestrial forcing. But they are also vulnerable to changes in climate and human activities that both influence species assemblages, sediment dynamics, water quality and hydrology. Sheskinmore Lough, located on the west coast of Donegal, northwest Ireland comprises a shallow (<1.5m) freshwater sedimentary lake surrounded by a diverse array of coastal and freshwater wetland and dune habitats supporting a plethora of rare and endangered species. The lake-wetland-dune complex, designated under the EU Habitats and Birds Directives, is managed by the National Parks and Wildlife Service (NPWS) who are concerned that declining water levels are driving negative impacts on protected flora and fauna; however their water management approach is reactionary, lacks an ecohydrological basis and is inherently unsustainable. The aim of this PhD is to inform conservation management strategies via multidisciplinary analysis of the ecohydrology of Sheskinmore Lough and its adjacent wetlands. The thesis examines the contemporary ecohydrology of the system, and reconstructs past environmental change using multiproxy paleolimnological techniques to ascertain the envelope of ecohydrological variability over different timescales. In addition, the research uses a distributed hydrological model to explore the impacts associated with climate change and hydrological management. The results reveal a lake and wetland system that has a complex contemporary ecohydrology set in a complicated coastal environment. Ecological analysis indicates an oligotrophic, circumneutral, shallow lake system, overlying a sedimentary complex dominated by peat and calcareous sandy substrates, fringed by a wetland system comprising fen and mire communities that also favour similar conditions. Hydrology was identified as a key factor influencing the distribution and composition of communities across the site. Operation of the sluice had the greatest impact, causing water levels to fluctuate rapidly (up to 1m in under 7 days) within the lake, with knock-on effects observed across a large part of the wetland system. Paleolimnological analyses revealed two important climatic and geomorphological shifts defining three key phases in the recent environmental and ecohydrological history of the site. First, a change occurred in the mid to late 1500s AD from a drier, sandy environment when the lake was primarily a riverine system, to one that was wetter and dominated by peat and ree dbe ds. The second transition occurred c.1800 AD when the climate became more turbulent, prompting the development of a lake-wetland system. Finally, modelling projections indicate the lake and wetland system are likely to experience increasing impacts in the future due to a more variable climate and lake water levels fluctuating more as a result. Ultimately, hydrological management coupled with climate change presents the greatest potential ecological threat to Sheskinmore Lough. This thesis therefore provides a series of conservation recommendations to enhance the preservation of similar freshwater systems, while the knowledge gained contributes significantly to the understanding of shallow aquatic ecohydrology

Altered serological and cellular reactivity to H-2 antigens after target cell infection with vaccinia virus

MICE generate cytotoxic T lymphocytes (CTL) which are able to lyse virus infected target cells in vitro after infection with lymphocytic choriomeningitis virus (LCMV) and pox-viruses1−3. CTL kill syngeneic and semiallogenic infected cells but not allogenic infected targets. Target cell lysis in these systems seems to be restricted by H-2 antigens, especially by the K or D end of the major histocompatibility complex (MHC). In experiments where virus specific sensitised lymphocytes kill virus infected allogenic target cells4 the effector lymphocytes have not been characterised exactly. Recent investigations suggest that the active cell in this assay, at least in the measles infection, is a non-thymus derived cell (H. Kreth, personal communication). An H-2 restriction of cell mediated cytolysis (CMC) to trinitrophenol (TNP)-modified lymphocytes has also been described5. Zinkernagel and Doherty6 postulated that the CTL is directed against syngeneic H-2 antigens and viral antigens and they suggested an alteration of H-2 induced by the LCMV infection. Earlier7 we found a close topological relationship between H-2 antigens and the target antigen(s) responsible for CMC in the vaccinia system. Here we report experiments which were carried out to prove alteration of H-2 after infection of L-929 fibroblasts with vaccinia virus

Identification of pyrolysis products of the new psychoactive substance 2-amino-1-(4-bromo-2,5- dimethoxyphenyl)ethan-1-one (bk-2C-B) and its iodo analog bk-2C-I

2-Amino-1-(4-bromo-2,5-dimethoxyphenyl)ethanone hydrochloride (bk-2C-B) has recently emerged as a new psychoactive substance (NPS). It is most commonly consumed orally although there are indications that it might also be ingested by inhalation or ‘smoking’. Information about the stability of bk-2C-B when exposed to heat is unavailable and the potential for pyrolytic degradation and formation of unknown substances available for inhalation prompted an investigation using a simulated ‘meth pipe’ scenario. Twelve products following pyrolysis of bk- 2C-B were detected and verified by organic synthesis of the corresponding standards. In addition, 2-amino-1-(4-iodo-2,5-dimethoxyphenyl)ethanone hydrochloride (bk-2C-I) has been characterized for the first time and subjected to pyrolysis as well. Similar products were formed, which indicated that the replacement of the bromo with the iodo substituent did not affect the pyrolysis pattern under the conditions used. Two additional products were detected in the bk-2C- I pyrolates, namely 1-(2,5-dimethoxyphenyl)-ethanone and 1-iodo-4-ethenyl-5-methoxyphenol. The potential ingestion of pyrolysis products with unknown toxicity adds an element of concern

Bio-Benchmarking of Electronic Nose Sensors

BACKGROUND:Electronic noses, E-Noses, are instruments designed to reproduce the performance of animal noses or antennae but generally they cannot match the discriminating power of the biological original and have, therefore, been of limited utility. The manner in which odorant space is sampled is a critical factor in the performance of all noses but so far it has been described in detail only for the fly antenna. METHODOLOGY:Here we describe how a set of metal oxide (MOx) E-Nose sensors, which is the most commonly used type, samples odorant space and compare it with what is known about fly odorant receptors (ORs). PRINCIPAL FINDINGS:Compared with a fly's odorant receptors, MOx sensors from an electronic nose are on average more narrowly tuned but much more highly correlated with each other. A set of insect ORs can therefore sample broader regions of odorant space independently and redundantly than an equivalent number of MOx sensors. The comparison also highlights some important questions about the molecular nature of fly ORs. CONCLUSIONS:The comparative approach generates practical learnings that may be taken up by solid-state physicists or engineers in designing new solid-state electronic nose sensors. It also potentially deepens our understanding of the performance of the biological system

CR1 Knops blood group alleles are not associated with severe malaria in the Gambia

The Knops blood group antigen erythrocyte polymorphisms have been associated with reduced falciparum malaria-based in vitro rosette formation (putative malaria virulence factor). Having previously identified single-nucleotide polymorphisms (SNPs) in the human complement receptor 1 (CR1/CD35) gene underlying the Knops antithetical antigens Sl1/Sl2 and McC(a)/McC(b), we have now performed genotype comparisons to test associations between these two molecular variants and severe malaria in West African children living in the Gambia. While SNPs associated with Sl:2 and McC(b+) were equally distributed among malaria-infected children with severe malaria and control children not infected with malaria parasites, high allele frequencies for Sl 2 (0.800, 1,365/1,706) and McC(b) (0.385, 658/1706) were observed. Further, when compared to the Sl 1/McC(a) allele observed in all populations, the African Sl 2/McC(b) allele appears to have evolved as a result of positive selection (modified Nei-Gojobori test Ka-Ks/s.e.=1.77, P-value &lt;0.05). Given the role of CR1 in host defense, our findings suggest that Sl 2 and McC(b) have arisen to confer a selective advantage against infectious disease that, in view of these case-control study data, was not solely Plasmodium falciparum malaria. Factors underlying the lack of association between Sl 2 and McC(b) with severe malaria may involve variation in CR1 expression levels

Astrocytic Ion Dynamics: Implications for Potassium Buffering and Liquid Flow

We review modeling of astrocyte ion dynamics with a specific focus on the implications of so-called spatial potassium buffering, where excess potassium in the extracellular space (ECS) is transported away to prevent pathological neural spiking. The recently introduced Kirchoff-Nernst-Planck (KNP) scheme for modeling ion dynamics in astrocytes (and brain tissue in general) is outlined and used to study such spatial buffering. We next describe how the ion dynamics of astrocytes may regulate microscopic liquid flow by osmotic effects and how such microscopic flow can be linked to whole-brain macroscopic flow. We thus include the key elements in a putative multiscale theory with astrocytes linking neural activity on a microscopic scale to macroscopic fluid flow.Comment: 27 pages, 7 figure

Clinicians' caseload management behaviours as explanatory factors in patients' length of time on caseloads : a predictive multilevel study in paediatric community occupational therapy

Peer reviewedPublisher PD

Characterizing solute hydrogen and hydrides in pure and alloyed titanium at the atomic scale

Ti has a high affinity for hydrogen and are typical hydride formers . Ti -hydride are brittle phases which probably cause premature failure of Ti -alloys. Here, we used atom probe tomography and electron microscopy to investigate the hydrogen di stribution in a set of specimens of commercially pure Ti , model and commercial Ti -alloys. Although likely partly introduced during specimen preparation with the focused- ion beam, we show formation of Ti-hydrides along α grain boundaries and α / β phase boundaries in commercial pure Ti and α + β binary model alloys . No hydrides are observed in the α phase in alloys with Al addition or quenched-in Mo supersaturation

Acceptability of a theory-based sedentary behaviour reduction intervention for older adults ('On Your Feet to Earn Your Seat').

Background: Adults aged 60 years and over spend most time sedentary and are the least physically active of all age groups. This early-phase study explored acceptability of a theory-based intervention to reduce sitting time and increase activity in older adults, as part of the intervention development process. Methods: An 8-week uncontrolled trial was run among two independent samples of UK adults aged 60–75 years. Sample 1, recruited from sheltered housing on the assumption that they were sedentary and insufficiently active, participated between December 2013 and March 2014. Sample 2, recruited through community and faith centres and a newsletter, on the basis of self-reported inactivity (<150 weekly minutes of moderate-to-vigorous activity) and sedentary behaviour (≥6 h mean daily sitting), participated between March and August 2014. Participants received a booklet offering 16 tips for displacing sitting with light-intensity activity and forming activity habits, and self-monitoring ‘tick-sheets’. At baseline, 4-week, and 8-week follow-ups, quantitative measures were taken of physical activity, sedentary behaviour, and habit. At 8 weeks, tick-sheets were collected and a semi-structured interview conducted. Acceptability was assessed for each sample separately, through attrition and adherence to tips, ANOVAs for behaviour and habit changes, and, for both samples combined, thematic analysis of interviews. Results: In Sample 1, 12 of 16 intervention recipients completed the study (25 % attrition), mean adherence was 40 % (per-tip range: 15–61 %), and there were no clear patterns of changes in sedentary or physical activity behaviour or habit. In Sample 2, 23 of 27 intervention recipients completed (15 % attrition), and mean adherence was 58 % (per-tip range: 39–82 %). Sample 2 decreased mean sitting time and sitting habit, and increased walking, moderate activity, and activity habit. Qualitative data indicated that both samples viewed the intervention positively, found the tips easy to follow, and reported health and wellbeing gains. Conclusions: Low attrition, moderate adherence, and favourability in both samples, and positive changes in Sample 2, indicate the intervention was acceptable. Higher attrition, lower adherence, and no apparent behavioural impact among Sample 1 could perhaps be attributable to seasonal influences. The intervention has been refined to address emergent acceptability problems. An exploratory controlled trial is underway