The Bioaccumulation of Persistent Organic Pollutants in Marine Species from Irish and Surrounding Waters

The presence of anthropogenic pollutants throughout all compartments of the marine environment have been of international concern for a number of decades. While a great number of datasets documenting “absolute” concentrations of persistent organic pollutants in a variety of marine biota are available, bioaccumulation, biomagnification and the fate of these compounds in the marine food web or marine ecosystem is often not possible. This thesis reports various analytical methodologies employed to determine levels of a wide scope of persistent organic pollutants in marine biota and traces the flow of carbon and nitrogen isotopes through the marine food web, ultimately applying bioconcentration and biomagnification modelling techniques to these data. Standardisation of sampling procedures and baseline levels of a wide range of lipophilic contaminants in a variety of marine species are reported. This thesis (and associated publications) report a number of new contaminant datasets in Irish marine species and reports that no adverse effects to the consumer of Irish fishery produce are currently expected from a number of contaminant groups including toxaphene, PBDEs and HBCD. Enantiospecific enrichment and trophic level status related accumulation of OCP compounds in killer whales is reported, with the first known use of stable isotope techniques to identify marine mammal dietary influences on a killer whale from British and Irish waters. Factors influencing pollutant bioaccumulation in commercially important and/or biologically sensitive species including, blue whiting, eels and killer whales are discussed. The role of stable isotopes in modelling contaminant bioaccumulation, trophic transfer within the marine web, as a means to establish dietary and/or habitat preference and the implications of findings on environmental and food safety monitoring programmes are discussed. Datasets and techniques reported demonstrate that stable isotope based techniques are powerful tools in environmental and food safety monitoring programmes thereby continuing to further protect both the consumer of marine produce, marine species and marine biodiversity

Using Social Media to Increase Accessibility to Online Teaching Resources.

The key learning points of Surgical Grand Rounds (SGR) are often not accessible at times of exam revision for students. We sought to use Twitter as an online teaching repository. A SGR Twitter profile was created. 23 SGR presentations were made accessible on Twitter over a 3 month period. 93 students were invited to complete a questionnaire assessing usage of the repository. 84 (90%) in total responded, of these, 25 (80.6%) felt that the online provision of SGR through twitter was useful . The majority (71%) felt that the online content was easily accessible. The novel use of social media is a useful adjunctive educational tool in accessing an online repository of SGR presentations

Spatial working memory for locations specified by vision and audition: Testing the amodality hypothesis

Spatial working memory can maintain representations from vision, hearing, and touch, representations referred to here as spatial images. The present experiment addressed whether spatial images from vision and hearing that are simultaneously present within working memory retain modality-specific tags or are amodal. Observers were presented with short sequences of targets varying in angular direction, with the targets in a given sequence being all auditory, all visual, or a sequential mixture of the two. On two thirds of the trials, one of the locations was repeated, and observers had to respond as quickly as possible when detecting this repetition. Ancillary detection and localization tasks confirmed that the visual and auditory targets were perceptually comparable. Response latencies in the working memory task showed small but reliable costs in performance on trials involving a sequential mixture of auditory and visual targets, as compared with trials of pure vision or pure audition. These deficits were statistically reliable only for trials on which the modalities of the matching location switched from the penultimate to the final target in the sequence, indicating a switching cost. The switching cost for the pair in immediate succession means that the spatial images representing the target locations retain features of the visual or auditory representations from which they were derived. However, there was no reliable evidence of a performance cost for mixed modalities in the matching pair when the second of the two did not immediately follow the first, suggesting that more enduring spatial images in working memory may be amodal

Correlation between the structure and the anticorrosion barrier properties of hybrid sol–gel coatings: application to the protection of AA2024-T3 alloys

Hybrid sol–gel materials have been extensively studied as viable alternatives to toxic chromate (VI)-based coatings for the corrosion protection of AA2024-T3 in the aerospace industry, due to the wide range of available chemistries they offer and the tremendous development potential of innovative functional coatings. However, so far, little work has been performed in identifying the effect of the employed chemistries on the structure and anticorrosion properties of the coatings. This work proposes to contribute to a better understanding of the relationship existing between the structure, morphology and anticorrosion properties of hybrid sol–gel coatings deposited on AA2024- T3 aluminium surfaces, the most widely used alloy in the aerospace industry. The sol–gels are prepared employing two hybrid precursors; an organosilane, 3-trimethoxysilylpropylmethacrylate, and a zirconium complex prepared from the chelation of zirconium n-propoxide, and methacrylic acid. The structure of the hybrid sol–gel formulation is modified by altering the concentration of the transition metal complex. The structure and morphology of the coatings are characterised by dynamic light scattering, fourier transform infrared spectroscopy, silicon nuclear magnetic resonance spectroscopy, differential scanning calorimetry, scanning electron microscopy, atomic-force microscopy and the anticorrosion barrier properties characterised by electrochemical impedance spectroscopy and neutral salt-spray. It is found that the transition metal concentration affected the morphology and structure, as well as the anticorrosion performances of the hybrid sol–gel coatings. A direct correlation between the morphology of the coatings and their final anticorrosion barrier properties is demonstrated, and the optimum material amongst this series is determined to be comprised of a concentration of between 20 and 30% of transition metal

Development and Characterisation of a Whole Hybrid Sol-Gel Optofluidic Platform for Biosensing Applications

This work outlines, for the first time, the fabrication of a whole hybrid sol-gel optofluidic platform by integrating a microfluidic biosensor platform with optical waveguides employing a standard photolithography process. To demonstrate the suitability of this new hybrid sol-gel optofluidic platform, optical and bio-sensing proof-of-concepts are proposed. A photoreactive hybrid sol-gel material composed of a photopolymerisable organically modified silicon alkoxide and a transition metal complex was prepared and used as the fabrication material for the entire optofluidic platform, including the optical waveguides, the sensing areas, and the microfluidic device. The most suitable sol-gel materials chosen for the fabrication of the cladding and core of the waveguides showed a RIC of 3.5 × 10-3 and gave thicknesses between 5.5 and 7 μm. The material was optimised to simultaneously meet the photoreactive properties required for the photolithography fabrication process and the optical properties needed for the effective optical operability of the microstructured waveguides at 532 and 633 nm with an integrated microfluidic device. The optical proof-of-concept was performed using a fluorescent dye (Atto 633) and recording its optical responses while irradiated with a suitable optical excitation. The biosensing capability of the platform was assessed using a polyclonal primary IgG mouse antibody and a fluorescent labelled secondary IgG anti-mouse antibody. A limit of detection (LOD) of 50 ug/mL was achieved. A correlation between the concentration of the dye and the emission fluorescence was evidenced, thus clearly demonstrating the feasibility of the proposed hybrid sol-gel optofluidic platform concept. The successful integration and operability of optical and microfluidic components in the same optofluidic platform is a novel concept, particularly where the sol-gel fabrication material is concerned

Passive sampling as a screening tool in Ireland for new and emerging chemicals

The challenges of monitoring our waters for compliance with WFD and the expansion of the list of organic chemicals that are to be added for monitoring, provides impetus for investigation of alternative monitoring approaches such as passive sampling. The work being carried out represents an important collaboration between two research centres (DCU & MI) together with agency (EA UK and Inland Fisheries Ireland) and industry (TelLab) to assess the potential of passive sampling in monitoring priority pollutants in Ireland. This work is underpinned by a some studies carried out in Ireland already by the Marine Institute and a vast array of literature in the area of priority pollutant monitoring. The impact of this study may lie in the establishment of a capability to utilise passive sampling in the monitoring programme in Ireland for WFD. This project pilots the use of passive sampling technology (PDMS and POCIS) combined with biota monitoring to assess the presence of priority substances in Irish surface waters. The project focuses in particular on new pollutants earmarked as candidates for the Annex X priority substances list under the EU Water Framework Directive e.g. E2 and EE2, pharmaceuticals, pesticides, PFOS etc. This considers the implications for compliance with current and proposed EQS and investigates the potential for incorporating passive sampling and biota testing in future compliance, investigative and trend monitoring. Results of water, biota and passive sampling will be presented together with an outline of the project over the next 12 months. Keywords: passive sampling, surface waters, coastal waters, WFD

Gamma motes for detection of radioactive materials in shipping containers

Shipping containers can be effectively monitored for radiological materials using gamma (and neutron) motes in distributed mesh networks. The mote platform is ideal for collecting data for integration into operational management systems required for efficiently and transparently monitoring international trade. Significant reductions in size and power requirements have been achieved for room-temperature cadmium zinc telluride (CZT) gamma detectors. Miniaturization of radio modules and microcontroller units are paving the way for low-power, deeply-embedded, wireless sensor distributed mesh networks

An Assessment of Dangerous Substances in Water Framework Directive Transitional and Coastal Waters 2007-2009

This report presents an assessment of hazardous substance contamination in Irish transitional and coastal waters. This was carried out in support of the EPA’s assessment of the quality status of surface waters (2007-2009) as required by the Water Framework Directive (Directive 2000/60/EC).Funder: Marine Institut

Biological Effects and Chemical Measurements in Irish Marine Waters

The overall aim of this project was to increase Ireland’s capacity for the generation of integrated monitoring of biological effects and chemical measurement data and for the completion of a pilot scale assessment of the quality of the Irish marine environment at a number of selected locations.Sea Change Strategy with the support of the Marine Institute and the Marine Research Sub Programme of the National Development Plan 2007-2013, and funding from the Environmental Protection Agency (EPA