NUI Maynooth Eprint Archive
Not a member yet
18159 research outputs found
Sort by
Party-Base Linkages and Contestatory Mobilization in Bolivia’s El Alto Subduing the Ciudad Rebelde
No full textConfrontations between Evo Morales’s Movement toward Socialism (MAS)-led government and sectors of his original support base have raised concerns regarding Bolivia’s
“process of change.” An empirical analysis of the Regional Workers’ Union and the
Federation of Neighborhood Associations in El Alto reveals that extensive and intensive
linkages forged between the MAS and its base during confrontations with conservative
forces weakened their contestatory efforts and fostered internal splits that the MAS and
the right-wing Unidad Nacional (UN) parties actively promoted. The upshot was the
emergence of two versions of each organization that existed side-by-side, one aligned with
the MAS, the other with UN, and the capacity of the base to hold the government to
popular demands was greatly diminished
On Optimal Quantized Non-Bayesian Quickest Change Detection With Energy Harvesting
No full textIn this paper, we consider a problem of decentralized non-Bayesian quickest change detection using a wireless sensor network where the sensor nodes are powered by harvested energy from the environment. The underlying random process being monitored by the sensors is subject to change in its distribution at an unknown but deterministic time point, and the sensors take samples (sensing) periodically, compute the likelihood ratio based on the distributions before and after the change, quantize it and send it to a remote fusion centre (FC) over fading channels for performing a sequential test to detect the change. Due to the unpredictable and intermittent nature of harvested energy arrivals, the sensors need to decide whether they want to sense, and at what rate they want to quantize their information before sending them to the FC, since higher quantization rates result in higher accuracy and better detection performance, at the cost of higher energy consumption. We formulate an optimal sensing and quantization rate allocation problem (in order to minimize the expected detection delay subject to false alarm rate constraint) based on the availability (at the FC) of non-causal and causal information of sensors' energy state information, and channel state information between the sensors and the FC. Motivated by the asymptotically inverse relationship between the expected detection delay (under a vanishingly small probability of false alarm) and the Kullback-Leibler (KL) divergence measure at the FC, we maximize an expected sum of the KL divergence measure over a finite horizon to obtain the optimal sensing and quantization rate allocation policy, subject to energy causality constraints at each sensor. The optimal solution is obtained using a typical dynamic programming based technique, and based on the optimal quantization rate, the optimal quantization thresholds are found by maximizing the KL information measure per slot. We also provide suboptimal threshold design policies using uniform quantization and an asymptotically optimal quantization policy for higher number of quantization bits. We provide an asymptotic approximation for the loss due to quantization of the KL measure, and also consider an alternative optimization problem with minimizing the expected sum of the inverse the KL divergence measure as the cost per time slot. Numerical results are provided comparing the various optimal and suboptimal quantization strategies for both optimization problem formulations, illustrating the comparative performance of these strategies at different regimes of quantization rates
The impact of automatic video auditing with real-time feedback on the quality and quantity of handwash events in a hospital setting
No full textBackground: Poor quality handwashing contributes to the spread of nosocomial infections. We investigate
the impact of automatic video auditing (AVA) with feedback on the quality and quantity of handwashing in a
hospital setting.
Methods: AVA systems were mounted over all handwash sinks in a surgical unit. Phase 1 established baseline
handwashing quality and quantity. Phase 2 examined the impact of real-time performance feedback, and
phase 3 examined the incremental impact of weekly team performance reports. Phase 4 remeasured the
baseline without feedback.
Results: A total of 3,606 handwash events were audited. During phase 2 and 3, compliance with the World
Health Organization technique improved from 15.7%-46% (P < .0001), and the average number of handwash
events per patient per day increased from 0.91-2.25 (P < .0001). Performance returned to baseline in phase 4.
Conclusions: AVA with real-time feedback significantly improved the quality and quantity of handwashing.
The combination of AVA with electronic monitoring will allow simultaneous auditing of hand hygiene quantity and quality. The impact of cognitive offloading onto the technology may have contributed to the return
to baseline at the end of the study, and suggests further research is required in this are
The Holy Well as a Window onto Irish Life—Pre-Christian, Christian, and Post-Christian
No full textThis is the revised version of a lecture delivered at Castlecoote House, Co. Roscommon, on November 21, 2019, as part of a series on ‘Contemporary Challenges to Faith and Politics’. It offers a quick overview of the historical development of holy wells in Ireland since pre-Christian times, followed by philosophical and theological reflections on their meaning and significance. The article closes with some thoughts on holy wells in the contemporary context
Evidence-Based Acquisitions (EBA): A case study from Maynooth University Library
No full textFollowing a scoping exercise in summer 2017, the Library embarked on an EBA Pilot Project. The new model enabled the engagement of students in the selection process based on their interaction with the resources. Furthermore, it lead to unanticipated and different levels of engagement with some departments who were traditionally less keen on ebooks. The EBA Working Group was awarded the Maynooth University (MU) President’s Award for Service Innovation in May 2019. This presentation will outline the pilot and its implementation at MU Library, highlighting some of the issues and discussing the benefits and impact of the model
Believing Anew: Gianni Vattimo and A Form of Faith in Contemporary Culture
No full textToday’s religious landscape is one that invites reflection on the place of faith, its cultural connections,and its future.This is, in part, due tothe variousreligious sensibilities at playin the present time. On the one hand, there is an attraction to astructured, doctrinal-based form ofreligionthat asksoneto recognise a particular authority and to surrender to it. On the other hand, there is a decline in the explicit practiceof religion.Our places of worship reflect these dwindling numbers,rows of once full pews now standingemptyas attendance falls.There are, of course, several reasons for this decline. Many simply cease practicing, while still professingthemselves to be believers; others are drawn to non-Christian religions and New Age practices; and someclaim that they have allegiance to any religion.Thereis, of course,a middle-ground between thetwo religious sensibilities, which will be the focus of this dissertation. Thismiddle-ground constitutes the reality, and the difficulty,ofdeveloping a religious life in contemporary culture. Itmight be best understood in terms ofa search for faith and meaningwithout, often,adheringto any particulardoctrinal framework or authority.Many are choosingto follow their own instincts in searching for something that willprovidea spiritual nourishment or enrichment fortheir lives. While the goal isto encounter somethingthat lies beyondourown selves, the seeker and their own personal experience remainsat the heart of this spiritual quest. As aseeker, oneis free to search, to engage with others, and to express oneselfwithout being confronted with a set framework of beliefs. This middle-ground is not necessarily free from all Christian influence; many events, courses, and spiritual practices are rooted in Christianity, yet retain the freedom for participants to ask and to answerwithout being restrictedby the parameters set by institutionalreligions.This search for meaningmarks a shift away from the emphasis on institutionsand beliefs, focusing more onthe pragmaticand experiential elements of faith as away of life
The Roles of a Conserved MAP Kinase Pathway in the Regulation of Development and Secondary Metabolism in Aspergillus Species
No full textIn order for eukaryotes to efficiently detect and respond to environmental stimuli, a myriad of protein signalling pathways are utilised. An example of highly conserved signalling pathways in eukaryotes are the mitogen-activated protein kinase (MAPK) pathways. MAPK pathways are responsible for the regulation of a diverse array of biological processes, such as cell proliferation, immune responses and metabolism, to name a few. In fungal organisms, MAPK pathways have been shown to be involved in the modulation of cell fusion and mating, asexual and sexual reproduction, cellular stress responses and secondary metabolism. MAPK pathways have been extensively studied in yeast, a model organism for unicellular fungi. One MAPK pathway in particular is known as the pheromone module, which consists of three kinases (Ste11, Ste7, Fus3), the adaptor protein Ste50 and the scaffold protein Ste5. This pathway is critical for the response to pheromone signalling between neighbouring yeast cells, resulting in the regulation of cell fusion, otherwise known as mating or sexual reproduction. Orthologous MAPK pathways have been studied in fungal species such as the model ascomycete Neurospora crassa. In this species, the pheromone module pathway has been shown to be involved in the regulation of germling and hyphal fusion, which is critical for the establishment of the interconnected fungal mycelium.
With respect to the genus Aspergillus, information regarding the influence of MAPK signalling pathways in the regulation of fungal development is limited. Orthologs of the core pheromone module components in yeast have been identified previously in the model filamentous fungus A. nidulans. These include the three kinases SteC, MkkB and MpkB (orthologs of yeast Ste11, Ste7 and Fus3 respectively) and the adaptor protein SteD (ortholog of yeast Ste50). However, there are no orthologs of the Ste5 scaffold in filamentous fungal genomes, suggesting a unique mechanism of regulation exists for the pheromone module pathway in species like A. nidulans. This led to the first aim of this research thesis which was to identify and characterise a scaffold candidate for the pheromone module in A. nidulans. We identified the AN2701 gene which encodes a large protein consisting of multiple WD40 repeats, which is characteristic of scaffold proteins. This gene is orthologous to the N. crassa ham5 gene which encodes a scaffold protein in the Mak-2 pheromone module pathway. For this reason, we named the protein product of the AN2701 gene ‘HamE’. Via a genetic and proteomic approach, we provided evidence that the HamE scaffold physically interacts with the kinases MkkB and MpkB and that a pentameric complex is formed at the
hyphal tips and plasma membrane. HamE is essential for the regulation of kinase phosphorylation levels and a hamE mutant exhibits dramatically reduced levels of MpkB phosphorylation, signifying reduced MAP kinase signalling and transcription factor activation. Deletion of any of the five members of the complex results in reductions in asexual sporulation, as well as complete inhibition of sexual cleistothecia formation and dramatic decreases in the expression levels of various secondary metabolite genes.
The next aim of this research thesis was to further characterise the roles of the pheromone module in Aspergillus species. Due to the dramatic defects in development and secondary metabolism observed in pheromone module mutants in A. nidulans, it was decided to assess whether the pheromone module could be utilised by other Aspergillus species to regulate their development and secondary metabolism. We found that orthologs of the pheromone module genes are highly conserved in the genus Aspergillus. We identified orthologs of each of the five core pheromone module components in two pathogenic fungi, A. flavus and A. fumigatus. A. flavus is a prolific producer of secondary metabolites such as the highly carcinogenic compound aflatoxin B1. This species is considered a major global threat as it is capable of causing contamination of a wide variety of agricultural crops and ingestion of crops contaminated with aflatoxin can lead to the development of hepatocellular carcinomas. A. fumigatus is an opportunistic human pathogen and is a major risk to immunocompromised individuals. This species produces dangerous secondary metabolites such as the immunosuppressant gliotoxin, which promotes invasive pulmonary aspergillosis and this can lead to mortality rates as high as 95% in immunocompromised patients.
In A. flavus, we provided evidence of the existence of a tetrameric pheromone module pathway, which is made up of two sub-complexes. Initially, MkkB and MpkB form a dimer at the hyphal tips, potentially in response to chemotropic interactions between neighbouring hyphae. The SteC-SteD dimer then interacts with the MkkBMpkB dimer in the cytoplasm and assembly of the complex results in phosphorylation and migration of MpkB into the nucleus, where it presumably interacts with various transcription factors. Interestingly, HamE was shown to localise to the hyphal tips but was not observed to interact with the pheromone module components, signifying a potentially unique mechanism of signalling in this species. Deletion of steC, mkkB, mpkB or steD results in inhibition of both asexual sporulation and sclerotia production.
Additionally, each of these mutants produced significantly lower levels of aflatoxin B1 and increased levels of other secondary metabolites, such as leporin B and cyclopiazonic acid. Deletion of hamE resulted in sexual sterility and reductions in aflatoxin B1 production, however, asexual sporulation was not hindered.
In A. fumigatus, via interactome data, we provided evidence of the existence of a pentameric pheromone module pathway, similar to what is observed in A. nidulans. The proteins of this pathway exhibited similar sub-cellular localisation patterns to those observed in A. flavus. HamE, MkkB and MpkB localise to the hyphal tips, suggesting that they form a trimeric complex. SteC interacts with SteD and this dimer associates with the trimeric complex in the cytoplasm to form a pentameric complex, allowing for kinase phosphorylation and translocation of MpkB into the nucleus. Deletion of any of the five pheromone module components results in dramatic reductions in asexual sporulation, vegetative growth rate and production of various secondary metabolites, particularly gliotoxin. Each mutant also exhibited increased sensitivity to both cell wall and oxidative stress agents.
Overall, this thesis provides a comprehensive analysis of the molecular roles of the pheromone module in Aspergillus species. These data suggest that this pathway is a conserved mechanism of signal transduction that is required for the regulation of fungal development and secondary metabolism. Findings from this thesis may contribute to the development of strategies which could involve targeting the components of the pheromone module in order to help prevent crop spoilage and infections caused by Aspergillus species
Discovery of a jet from the single HAe/Be star HD 100546
No full textYoung accreting stars drive outflows that collimate into jets, which can be seen hundreds of au from their driving sources. Accretion
and outflow activity cease with system age, and it is believed that magneto-centrifugally launched disk winds are critical agents in
regulating accretion through the protoplanetary disk. Protostellar jets are well studied in classical T Tauri stars (M? . 2 M�), while
few nearby (d . 150 pc) intermediate-mass stars (M? = 2−10 M�), known as Herbig Ae/Be stars, have detected jets. We report
VLT/MUSE observations of the Herbig Ae/Be star HD 100546 and the discovery of a protostellar jet. The jet is similar in appearance
to jets driven by low-mass stars and compares well with the jet of HD 163296, the only other known optical jet from a nearby
Herbig Ae/Be star. We derive a (one-sided) mass-loss rate in the jet of log M˙
jet ∼ −9.5 (in M� yr−1
) and a ratio of outflow to accretion
of roughly 3 × 10−3
, which is lower than that of CTTS jets. The discovery of the HD 100546 jet is particularly interesting because the
protoplanetary disk around HD 100546 shows a large radial gap, spiral structure, and might host a protoplanetary system. A bar-like
structure previously seen in Hα with VLT/SPHERE shares the jet position angle, likely represents the base of the jet, and suggests a
jet-launching region within about 2 au. We conclude that the evolution of the disk at radii beyond a few au does not affect the ability
of the system to launch jets
Impedimetric and electrochemical evaluation of a new redox active steroid derivative for hormone immunosensing
No full textPreparation and electrochemical interrogation of a novel redox active progesterone derivative progesterone
thiosemicarbazone (PATC) is presented here together with an investigation into its suitability as conjugate in
progesterone hormone immunosensing. PATC synthesis involved a condensation reaction between progesterone
acetate and thiosemicarbazone hydrochloride. Voltammetric and pulse techniques confirmed the redox behaviour of the new compound with concentration and scan rate dependant irreversible behaviour evident at glassy
carbon and gold transducers - ko (standard heterogeneous rate constant) was 2.56 � 10-3 cm2
/s (ν ¼ 100 mV/s in
non-aqeuous media). Bioaffinity studies towards anti-progesterone antibodies involved a competitive ELISA
format (optical) which confirmed recognition of the new progesterone derivative. Electrochemical impedance
spectroscopy was employed as an interrogation technique in order to establish optimum binding and surface
conditions for progesterone antigen-antibody interaction with the assistance of a redox probe (potassium
hexacyanoferrate)