NUI Maynooth Eprint Archive
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Zonal control on Holocene precipitation in northwestern Madagascar based on a stalagmite from Anjohibe
No full textThe Malagasy Summer Monsoon is an important part of the larger Indian Ocean and tropical monsoon region. As the effects of global warming play out, changes to precipitation in Madagascar will have
important ramifications for the Malagasy people. To help understand how precipitation responds to climate changes we present a long-term Holocene speleothem record from Anjohibe, part of the Andranoboka cave system in northwestern Madagascar. To date, it is the most complete Holocene record from this region and sheds light on the nature of millennial and centennial precipitation changes in this region. We find that over the Holocene, precipitation in northwestern Madagascar is actually in phase with the Northern Hemisphere Asian monsoon on multi-millennial scales, but that during some shorter centennial-scale events such as the 8.2 ka event, Anjohibe exhibits an antiphase precipitation signal to the Northern Hemisphere. The ultimate driver of precipitation changes across the Holocene does not appear to be the meridional migration of the monsoon. Instead, zonal sea surface temperature gradients in the Indian Ocean seem to play a primary role in precipitation changes
in northwestern Madagascar
Factors Associated with PrEP Stigma Among Gay, Bisexual, and Other Men Who Have Sex with Men (gbMSM): A Systematic Review
No full textGay, bisexual, and other men who have sex with men (gbMSM) are disproportionately affected by HIV. While pre-exposure pro-phylaxis (PrEP) is highly effective at preventing HIV acquisition, uptake of PrEP among gbMSM is low, which may in part be due to stigma associated with PrEP use. This systematic review aimed to explore experiences of PrEP stigma and to identify factors associated with this. Four databases were searched for papers including terms relating to (i) gbMSM, (ii) PrEP, and (iii) stigma, with narrative synthesis used to analyze results. After screening, 70 studies were included in the final analysis. Experiences of PrEP stigma were found to be characterized by a number of stereotypes and came from a range of sources. Five categories of factors were associated with stigma: (i) healthcare- related factors, (ii) cultural and contextual factors, (iii) socio-demographic factors, (iv) peer-discussion, and (v) psychosocial factors. These findings suggest that stigma can be a common experience for gbMSM. However, some are more at risk than others. Interventions aimed at reducing PrEP stigma may be useful in increasing uptake
The Detection and Removal of Pollutants in Aquatic Environments: Developing Sensitive Electrochemical Sensors and Using Magnetic Adsorbents
No full textWith the rapid development of industry and economies across the world, the problem of
environmental pollution in aquatic environments has become one of the key issues
facing the World. Consequently, the development of efficient and sensitive analytical
techniques to determine the levels of organic pollutants in water environments and
cost-effective strategies to remove these pollutants, are now more important than ever
before.
In this thesis, sensitive and selective electrochemical sensors with very good long-term
stability were developed for the detection of 4-chloro-2-methylphenoxyacetic acid
(MCPA), p-nitrophenol (p-NP), metronidazole (MTZ), and levofloxacin (LEVO). Two
strategies were employed in the development of these sensors. Firstly, glassy carbon
electrode (GCE) was activated to generate active sites to enhance the electron-transfer
process. Secondly, binder-free nanocomposites were employed to facilitate the detection
of MCPA, p-NP, MTZ and LEVO. The nanocomposites included graphene, bismuth
and copper nanostructures. These were all formed using electrodeposition, avoiding the
need to use binders that are typically employed with drop casting. Using these
approaches, impressive limits of detection of 8.0 nM, 0.18 nM, 0.9 nM and 11.86 nM
were achieved in the electrochemical detection of (1) MCPA at activated GCE, (2) p-NP
with bismuth dendrites deposited onto activated GCE, (3) MTZ with the sequential
electrodeposition of graphene nanoplatelets (Gr) and bismuth and (4) LEVO with the
sequential electrodeposition of Gr and copper at GCE, respectively. Further, graphene
supported magnetic nanocomposites (Gr/Fe) were fabricated and used as adsorbents for
the potential removal of MCPA, p-NP, MTZ and LEVO from aquatic environments.
Iron nanostructures were employed as the magnetic component. These nanocomposites
not only prevent the aggregation of the graphene sheets, but also can endow graphene
with magnetic properties. This makes the magnetic graphene adsorbents easy to separate
by external magnetic fields, greatly simplifying the recycling process. The adsorption
kinetics and adsorption isotherms were studied, and the reproducibility, selectivity and
reusability of the magnetic Gr/Fe composites were evaluated
Grid integration aspects of wave energy
No full textTraditional fossil fuel power plants release substantial amounts of greenhouse gases,
primarily contributing to anthropogenic climate change. Integrating renewable energy
sources into the energy supply systems is crucial to mitigate these environmental
challenges. One untapped renewable energy source is wave energy, which can contribute
to the transition towards a 100% renewable future.
Initially, this thesis presents a case for the potential value of adding wave energy to the
electric grid by analysing the complementarity of the wave resource with other renewable
energy modalities (wind, tidal and solar) and load requirements in the Island of Ireland.
The analysis shows that wave energy has a role to play in the future Irish supply mix.
Wave energy, like other renewable energy resources, presents a considerable challenge
for integrating it into the power grid due to its intermittent, and relatively unpredictable
nature. Wave energy grid integration entails several issues, including managing power
output variability, effective control of the wave energy device and power converters,
and optimal storage requirements. Additionally, an added complexity in wave energy
grid integration lies in implementing reactive wave energy converter (WEC) control,
which requires bi-directional power flow between the device and grid sides.
In general, many grid integration studies involving wave energy have deficiencies, such
as simplified hydrodynamic and power converter models, simplified passive damping
hydrodynamic control and relatively rudimentary PI power converter control. It is
imperative to address the issues mentioned above to enhance the integration of wave
energy into power grids, maximising power capture and the economic benefit of wave
energy. To this end, this thesis presents a wave-to-grid (W2G) control framework for a
direct-drive wave energy conversion system, including control-oriented models for each
component in the powertrain and high-performance controllers for both device and
grid sides, to achieve a range of control objectives. A short-term ultra-capacitor-based
storage system supports both device-side (hydrodynamic control support) and grid-side
(grid support during faults and power quality improvement) functionalities.
Additionally, the negative (reactive) power peaks are analysed by recognising the
importance of reactive power requirements of reactive hydrodynamic WEC control and
its implications for the powertrain equipment. As a result, this thesis provides analytical
and simulation results regarding the excessive reactive power peaks requirements of
hydrodynamic WEC control and offers recommendations on how to deal with them
‘Post-fascism’, or how the far right talks about itself: the 2022 Italian election campaign as a case study
No full textWhile the mainstreaming of the far right is attracting growing scholarly interest based on its contemporary relevance, the role that far-right self-representation strategies play in this process has seen limited engagement. In this article, we argue that far-right actors employ a post-fascist logic to bring their ideas closer to the mainstream. This logic rests on a dual message, whereby they attempt to outwardly distance themselves from fascism while at the same time recontextualising fascist ideas. To explore these dynamics, we use a mixed-methods approach to discourse analysis to examine far-right social media posts during the 2022 Italian general election. Taking all Facebook, Instagram and Twitter posts during the official campaigning period from the party and leader accounts of Lega per Salvini Premier and Fratelli d’Italia, we explored articulations of the post-fascist dyad within this context. Our findings underscore how both far-right parties ridiculed accusations of fascism and depicted themselves as ‘centre-right’, yet they commonly used fascist dog-whistles and violent anti-immigration discourse to construct a broader conspiracy narrative and portray themselves as Italy's saviour. While Italy proves a paradigmatic case, this research has wider implications for the need to explore the relationship between self-representation and mainstreaming
The mental health needs of social work students: findings from an Irish survey
No full textIt is important to consider the mental health of social work students
to promote their wellbeing and to ensure they are prepared for the
potential stressors of practice. This cross-sectional survey of social
work students (n = 240), the first of its kind on the island of Ireland,
provides findings on mental health and a range of associated issues
which can help to improve student welfare; the content of social
work courses; social work practice; and so, outcomes for service
users. The article discusses implications for the delivery of social
work education internationally
The MSC-EV-microRNAome: A Perspective on Therapeutic Mechanisms of Action in Sepsis and ARDS
No full textMesenchymal stromal cells (MSCs) and MSC-derived extracellular vesicles (EVs) have emerged as innovative therapeutic agents for the treatment of sepsis and acute respiratory distress syndrome (ARDS). Although their potential remains undisputed in pre-clinical models, this has yet to be translated to the clinic. In this review, we focused on the role of microRNAs contained in MSC-derived EVs, the EV microRNAome, and their potential contribution to therapeutic mechanisms of action. The evidence that miRNA transfer in MSC-derived EVs has a role in the overall therapeutic effects is compelling. However, several questions remain regarding how to reconcile the stochiometric issue of the low copy numbers of the miRNAs present in the EV particles, how different miRNAs delivered simultaneously interact with their targets within recipient cells, and the best miRNA or combination of miRNAs to use as therapy, potency markers, and biomarkers of efficacy in the clinic. Here, we offer a molecular genetics and systems biology perspective on the function of EV microRNAs, their contribution to mechanisms of action, and their therapeutic potential
Minoritized mother politicians in Ireland: Subjectivities and subjectivation in the political workplace
No full textMinoritized mother politicians that include ethnic racialized minority Traveller (an Irish indigenous community), racialized ethnic minority women, and migrant women face considerable disadvantages as workers arising from the intersection of their maternal status, gender, racialized or migrant and class position. The experiences of minoritized mother candidates and politicians in Ireland are viewed through the lens of subjectivities providing insight into how these mother-workers mediate identities and status positions that place them outside of, or in tension with, a predominantly white masculinist workplace. Empirical data analysis reveals how minoritized mother candidates and politicians respond in strategic ways to forces of subjectivation that may risk affirming idealized motherhood, while obscuring gendered and racialized inequalities in the political workplace. Paradoxically, motherhood seeds political ambition while acting as a material, temporal, and affective constraint, a source of invisible labor and violence in gendered and racialized ways. However, minoritized mothers' presence and representations also offer an important challenge to this white masculinist workplace
Analysing the Impacts of Dynamically Evolving Selection Policies in Monte Carlo Tree Search Through Evolutionary Algorithms
No full textThis thesis presents an innovative exploration into the synergy between Monte Carlo Tree
Search (MCTS) and Evolutionary Algorithms (EAs), focusing on the evolution of selection
policies within MCTS. MCTS, a powerful and versatile algorithm, has seen widespread
adoption in various domains, from strategic gaming to robotics, due to its ability to
effectively navigate large and complex decision spaces. However, the adaptability of its
selection policy, a critical factor in its performance, remains a challenging aspect that
demands further research.
The primary aim of this work is to investigate how evolutionary processes can be
harnessed to adaptively evolve MCTS’s selection policies online, thus enhancing the algorithm’s
efficiency and robustness in different problem landscapes, as well as in different
stages of the search. By integrating EAs into MCTS, this thesis explores the dynamic and
context-aware exploration of the search space, potentially surpassing the performance of
traditional approaches.
The thesis lays the groundwork for understanding the fundamentals of MCTS and
EA embeddings for online decision-making. It offers a detailed survey on the integration
of MCTS and EAs, particularly focusing on enhancing MCTS’s selection policy without
prior exposure to the domain.
A series of test problems, including the Function Optimisation Problem and proposed
simplifications of the board game Carcassonne, provide a platform to evaluate the interaction
between MCTS’s tree policy and game tree characteristics. Empirical analyses
of evolved selection policies are presented, comparing them with traditional MCTS and
Minimax approaches and assessing their performance.
The thesis aims to contribute significantly to AI and decision-making algorithms by
advancing the integration of evolutionary strategies within MCTS. It focuses on developing
adaptable and effective selection policies, examining the role of every aspect of
the evolutionary processes, and refining EA integration for enhanced decision-making
efficiency in MCTS
Data on the saturation behaviour of the 63-90 µm quartz from the Carpathian Basin
No full textThis dataset offers valuable insights into the luminescence saturation behaviour of 63–90 μm quartz grains sourced from the Carpathian Basin, as examined under controlled laboratory conditions. Its significance lies not only in shedding light on the luminescence properties specific to this region but also in facilitating comparative analyses with quartz samples from other geographic areas. Moreover, the dataset contributes novel findings to the ongoing investigations concerning the upper dating limit of quartz grains, which holds implications for refining luminescence dating methodologies. Grounded in the framework of several previous studies which underscore the challenges associated with utilizing quartz from certain regions for precise dose measurements,the dataset addresses the crucial aspect of setting upper dose limits for accurate luminescence dating. Consequently, the study conducts a series of tests to assess the proximity of natural sensitivity-corrected luminescence signals to laboratory saturation levels, particularly focusing on quartz samples from the Kisiljevo loess-palaeosol sequence. The dataset includes data from OSL saturation experiments conducted on sample 23019, along with associated calculations encompassing all 19 collected samples. This comprehensive serves as a valuable resource for researchers and practitioners engaged in luminescence dating studies, offering detailed insights into saturation behaviours and dose-response characteristics of quartz grains from the Carpathian Basin. Beyond its immediate research implications, the dataset holds significant potential for reuse in various contexts. Researchers exploring luminescence properties of geological materials, particularly quartz grains, can leverage this dataset to compare saturation behaviours across different regions, thus enriching our understanding of luminescence dating methodologies on a broader scale. Additionally, the dataset could inform future studies on refining dose limits and calibration protocols, ultimately enhancing the accuracy and reliability of luminescence dating techniques. In summary, this dataset not only advances our understanding of luminescence saturation behaviours in quartz grains from the Carpathian Basin but also fosters collaborative research efforts aimed at refining luminescence dating methodologies and addressing broader questions in geochronology and palaeoenvironmental studies