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Implications of Cardiovascular Ageing for Cerebral Perfusion and Cognitive Performance
No full textThe aim of this thesis is to examine how common manifestations of cardiovascular ageing, Orthostatic Hypotension and Atrial Fibrillation, affect cerebral perfusion and cognitive function in Irish adults. Associations between Orthostatic Hypotension, Atrial Fibrillation and cognitive function are examined in this thesis. In addition, mechanisms by which Orthostatic Hypotension and Atrial Fibrillation may impact on brain health are studied by examining their impact on cerebral perfusion.
Five quantitative studies are presented in this thesis, which use data from The Irish Longitudinal Study on Ageing (TILDA), a large population representative cohort study of Irish adults over the age of 50.
In this thesis, individuals with Atrial Fibrillation are found to be more likely to have Orthostatic Hypotension. In addition, Orthostatic Hypotension is found to be associated with cognitive decline in an Irish population, and cerebral haemodynamics in response to orthostasis are also impaired. While Atrial Fibrillation was not found to be robustly associated with cognitive decline, it was found to impair cerebral haemodynamics in response to orthostasis.
Impaired cerebral haemodynamics in response to standing in individuals with Orthostatic hypotension and Atrial Fibrillation demonstrated in this thesis may contribute to cognitive decline
Long term field trials demonstrate sustainable nutrient supply and uptake in rehabilitated bauxite residue
No full textEstablishing a sustainable vegetation cover is one of the most important steps in progressive rehabilitation and final closure of ore-processing residues and tailings facilities. Sustainable rehabilitation partly depends on establishing and maintaining a supply of plant-available nutrients, but few long term field studies demonstrating the
success or failure of rehabilitation of degraded land such as mineral processing tailings have been reported. Bauxite-processing residues are a highly sodic, highly alkaline, nutrient-poor by-product generated from alumina extraction, and pose many challenges for successful rehabilitation. This study investigated long term performance
of rehabilitation established on bauxite-processing residue storage areas (RSAs) by comparing the nutrient content of the vegetation cover with nutrient concentrations in the underlying residue sand. Five plant species having diverse physiology were selected from rehabilitation varying in age from 1 to 10 years old; these being: Hardenbergia comptoniana – a vigorous growing legume ground cover/creeper), Acacia cochlearis
and A. rostellifera - legume shrubs tolerant of sandy, alkaline conditions, Grevillea crithmifolia - a drought-tolerant proteaceous shrub tolerant of alkaline soil, and Spyridium globulosum - a robust, fast-growing shrub, commonly found on alkaline coastal soils. Gypsum incorporation reduced the pH and soluble aluminium levels in residue sand, but also acted as a long-term source of nutrients for the vegetation cover. Legume species
contained more nitrogen than non-legumes (2.5% N and 1.5% N, respectively), and decomposition of surface litter increased organic carbon and total and mineral nitrogen contents of the residue sand over time. Nutrient cycling maintained a supply of macro- and micro- nutrients for the vegetation cover, and 10-year old rehabilitation
exhibited characteristics similar to an analogue site. This study highlighted the important
accumulation, developing a functional microbial community, and a diverse plant species mix on transforming the residue sand characteristics and encouraging nutrient cycling as key mechanisms for establishing a sustainable vegetation cover and functional ecosystem on residue sand embankments
Visual media and the reconfiguration of divinity in Moldovan radical religion
No full textThis paper explores the power of the visual to contest and subvert dominant religious beliefs and doctrines. Through an exploration of Inochentism, and its later off-shoot Archangelism, ‘home-grown’ religious movements in twentieth and twenty first century Moldova, I trace the power of visual media, when combined with folk narratives, prophesy and visionary literature, to contest state and church authority, embody the sacred and transform belief. The two movements discussed, driven underground by nationalist and communist regimes in Romania and Soviet Moldavia, deployed visual media in the form of vernacular icons, photographs and photomontages, as powerful tools for critique and as a means of mobilizing belief during periods of intense persecution by the state. Based on a series of interviews with members of these movements between 2011 and 2014, on secret police archival sources and on Soviet propaganda publications, I examine how, under the pressure of state atheist ideology and political oppression, relations between divine and human, this world and the next, and the material and immaterial were re-imagined, re-presented and embodied by Moldovan village people
An examination of maximum legal application rates of dairy processing and associated STRUBIAS fertilising products in agriculture
No full textThe dairy industry produces vast quantities of dairy processing sludge (DPS), which can be processed further to develop second generation products such as struvite, biochars and ashes (collectively known as STRUBIAS). These bio-based fertilizers have heterogeneous nutrient and metal contents, resulting in a range of possible application rates. To avoid nutrient losses to water or bioaccumulation of metals in soil or crops, it is important that rates applied to land are safe and adhere to the maximum legal application rates similar to inorganic fertilizers. This study collected and analysed nutrient and metal content of all major DPS (n = 84) and DPS-derived STRUBIAS products (n = 10), and created an application calculator in MS Excel™ to provide guidance on maximum legal application rates for ryegrass and spring wheat across plant available phosphorus (P) deficient soil to P-excess soil. The sample analysis showed that raw DPS and DPS-derived STRUBIAS have high P contents ranging from 10.1 to 122 g kg− 1. Nitrogen (N) in DPS was high, whereas N concentration decreased in thermo-chemical STRUBIAS products (chars and ash) due to the high temperatures used in their formation. The heavy metal content of DPS and DPS-derived STRUBIAS was significantly lower than the EU imposed limits. Using the calculator, application rates of DPS and DPS-derived STRUBIAS materials (dry weight) ranged from 0 to 4.0 tonnes ha− 1 y− 1 for ryegrass and 0–4.5 tonnes ha− 1 y− 1 for spring wheat. The estimated heavy metal ingestion to soil annually by the application of the DPS and DPS-derived STRUBIAS products was lower than the EU guideline on soil metal accumulation. The calculator is adaptable for any bio-based fertilizer, soil and crop type, and future work should continue to characterise and incorporate new DPS and DPS-derived STRUBIAS products into the database presented in this paper. In addition, safe application rates pertaining to other regulated pollutants or emerging contaminants that may be identified in these products should be included. The fertilizer replacement value of these products, taken from long-term field studies, should be factored into application rates
Comparison of denitrification induced by various organic substances - reaction rates, microbiology and temperature effect
No full textWidespread groundwater pollution with nitrate (NO3−) and the finite and decreasing geogenic NO3− degradation capacity in aquifers require a better understanding of potential treatment methods. This project aimed at exploring and comparing the efficiency of four organic substances as electron donors for heterotrophic denitrification. Circulation column experiments using sediment without NO3− degradation capacity and high agricultural NO3− groundwater were conducted. Acetate, glucose, ascorbic acid, and ethanol were added to these columns in three concentration steps to induce biological denitrification, whereby also temperature dependence of denitrification rates (room temperature and typical groundwater temperature of 10°C) was taken into account. Results show denitrification with all four carbon (C) sources with intensities varying considerably between electron donors. Comparison of the two temperature approaches shows substantial differences between applied organic substances and indicates T as an important variable for denitrification. Ethanol is clearly the most effective electron donor for biodenitrification in groundwater investigated in this study, with a stronger and more effective NO3− degradation at 10°C than at room temperature. In contrast, much higher reaction rates are achieved with glucose at room temperature, compared to 10°C. Denitrification with ascorbic acid is very low at both temperatures; its addition produces biomass which repeatedly led to column clogging. In the entire test series, nitrite (NO2−) accumulation occurred more frequently and in higher concentrations at 10°C. Analysis of microorganisms shows a strong modification in microbial community in reaction to the addition of different organic C as well as between the two temperature approaches
Enhancing integration of disaster risk and climate change adaptation into Irish emergency planning
No full textThis chapter critically assesses the integration of climate change adaptation and disaster risk reduction with a special focus on the Irish policy and governance context. The chapter first presents a comprehensive overview of the Irish policy environment for climate change adaptation and disaster risk reduction including its current level of integration. Analysis of alignment with global and regional drivers of integration is then considered. Next, drawing on empirical research conducted with multidisciplinary experts across the Republic of Ireland, the chapter employs the SHIELD model, developed by the EU-funded ESPREssO project, which outlines six pathways to enhance integration across the domains of climate change adaptation and disaster risk reduction. The pathways comprise of sharing knowledge, harmonising capacities, institutionalising coordination, engaging stakeholders, leveraging investments and developing communication. Findings of stakeholder focus groups and survey responses highlight the challenges and opportunities for impactful integration between climate change adaptation and disaster risk reduction in Ireland from a practitioner perspective across the six SHIELD pathways. Finally, conclusions from the study indicate the importance of governance, management and coordination of systems for climate change adaptation and disaster risk reduction; the sequencing of policy-making, planning and research; and the significance of specificity in relation to use of the six SHIELD pathways
Non-planar anomalous dimensions in super Yang-Mills theories
No full textConformal supersymmetric Yang--Mills theories play an important role in the gauge-gravity correspondence and, despite being highly non-physical, have been a driving force for many new approaches in more realistic theories like QCD and gravity. An important class of objects in conformal field theories is the spectrum of scaling dimensions of local operators, specifically their non-trivial coupling-dependent parts, the anomalous dimensions. The discovery of integrability in planar maximally supersymmetric Yang--Mills theory led to considerable advances in the computation of its anomalous-dimension spectrum. Less is known at the non-planar level where the theory is assumed to be non-integrable. In this thesis we consider non-planar anomalous dimensions in conformal supersymmetric Yang--Mills theories with gauge group SU(N) and approach them by a number of means.
First, we use an on-shell form-factor approach based on the intimate connection between the dilatation operator and scattering amplitudes. The former gives rise to operator mixing and its diagonalisation gives the operators\u27 anomalous dimensions. The latter are basic observables in any quantum field theory, describing its interactions and linking theoretical developments to experimental investigations. A lot of progress has been made in recent years in the study of scattering amplitudes due to the advent of on-shell methods which circumvent many difficulties of more traditional approaches, and we use some of these here to extract the dilatation operator in certain sectors of the theories considered. In particular, we study a set of dimension-4 operators in N = 4 supersymmetric Yang--Mills theory that is relevant for the mixing of the theory\u27s on-shell Lagrangian, and compute the spectrum of non-planar anomalous dimensions in this sector. Furthermore, we extract the general form of the one-loop dilatation operator in the sector of purely scalar operators in the beta-deformed version of this theory.
In the planar limit of the theories considered in this thesis, the dilatation operator maps to a spin-chain Hamiltonian that can be diagonalised by integrability techniques, in particular a suitable Bethe ansatz. In this mapping the spectrum of anomalous dimensions becomes the energy spectrum of the corresponding spin chains. When going away from the planar limit, integrability is lost, but we can compute non-planar corrections to the planar spectrum using Rayleigh--Schroedinger perturbation theory. Using the basis of Bethe states, we compute matrix elements of the deformed and undeformed dilatation operator relevant in this approach. We find compact expressions in terms of off-shell scalar products and hexagon-like functions. We then use non-degenerate perturbation theory to compute the leading 1/N^2 corrections to operator dimensions and as an example compute the large R-charge limit for two-excitation states through subleading order.
Finally, we numerically study statistical properties of large sets of anomalous dimensions which we obtain from a direct diagonalisation of the dilatation operators discussed in this thesis. Specifically, we analyse the distribution of level spacings in these spectra and find universal features: in the planar limit it follows the Poisson distribution characteristic of integrable systems, and at finite values of N it transitions to the Wigner--Dyson distribution of the Gaussian orthogonal ensemble of random matrix theory. This provides numerical evidence that perturbative non-planar anomalous-dimension spectra are quantum-chaotic, which is further supported by similar findings in the spectral rigidity measuring long-range interactions in the spectra. We also demonstrate that the finite-N eigenvectors possess properties of chaotic states
Phosphorus recovery as struvite from hydrothermal carbonization liquor of chemically produced dairy sludge by extraction and precipitation
No full textPhosphorus (P) recovery from dairy wastewater involves its accumulation into phosphorus-rich sludge using a physico-chemical or biological process. The high iron content in chemical sludge decreases its usability in agricultural activities. The hydrothermal carbonization (HTC) is an option used to treat the sludge to obtain
hydrochar for various applications, including its use as an energy source and as a carbon-dense material. The HTC process leaves a bigger volume of nutrient-rich liquor, which phosphorus (P) purification was the subject of this work. By direct precipitation, the product iron content was 17.96%, a value higher than accepted limits for phosphate fertilizers. Thus, P extraction followed by struvite precipitation was studied. The use of oxalic acid extracted 86.7% of P from HTC liquor, while 86.6% of iron was removed. The process conditions of pH 9, and salt dosage of 1.73:1.14:1 for Mg:NH4 +:P mole ratio for struvite precipitation were obtained with a P recovery of 99.96%, and the effluent P concentration below 2 mg∙L− 1. The quality of products as fertilizers was tested by both in-vitro and in-vivo assays. High iron content in the product demonstrated a negative effect on plant germination, whilst the precipitation product from P extract demonstrated an advantage of P purification into struvite for plant macro and micronutrient availability. The used method of P extraction followed by struvite precipitation is useful for both P and iron recovery into two separate products with agricultural and chemical applications, respectively
Reconciling the Cultural Complexity of Research Data: Can we Make Data Interdisciplinary without Hiding Disciplinary Knowledge
No full textWhat is the optimal weight for gold in a portfolio?
No full textWe show that the statistical properties of gold are negatively correlated with equities and that including gold in a portfolio will provide diversification benefits. As there is no consensus on the proportion of gold that should be included in a strategic portfolio allocation we propose a visual tool that associates a performance metric with a range of possible asset weighting schemes—a Sharpe ratio response surface. This very surface shows that a target performance metric can be achieved with a large number of different allocations. We further argue that the rebalancing approach based on the surface closest to the benchmark surface under the Hausdorrf distance metric should be selected. Using a data sample between 1990 and 2018, we find that annual rebalancing with a 44-week lookback period achieves the minimum distance from the benchmark surface