Physical Sciences and Mathematics Commons^™

Mode-Sum Prescription For The Vacuum Polarization In Odd Dimensions, Peter Taylor, Cormac Breen

Articles

We present a new mode-sum regularization prescription for computing the vacuum polarization of a scalar field in static spherically-symmetric black hole spacetimes in odd dimensions. This is the first general and systematic approach to regularized vacuum polarization in higher dimensions. Remarkably, the regularization parameters can be computed in closed form in arbitrary dimensions and for arbitrary metric function $f(r)$. In fact, we show that in spite of the increasing severity and number of the divergences to be regularized, the method presented is mostly agnostic to the number of dimensions. Finally, as an explicit example of our method, we show plots …

Argumentation For Knowledge Representation, Conflict Resolution, Defeasible Inference And Its Integration With Machine Learning, Luca Longo

Conference papers

Modern machine Learning is devoted to the construction of algorithms and computational procedures that can automatically improve with experience and learn from data. Defeasible argumentation has emerged as sub-topic of artificial intelligence aimed at formalising common-sense qualitative reasoning. The former is an inductive approach for inference while the latter is deductive, each one having advantages and limitations. A great challenge for theoretical and applied research in AI is their integration. The first aim of this chapter is to provide readers informally with the basic notions of defeasible and non-monotonic reasoning. It then describes argumentation theory, a paradigm for implementing defeasible …

An Examination Of The Neural Unreliability Thesis Of Autism, John Butler, Sophie Molholm, Gizely Andrade, John J. Foxe

Articles

An emerging neuropathological theory of Autism, referred to here as “the neural unreliability thesis,” proposes greater variability in moment-to-moment cortical representation of environmental events, such that the system shows general instability in its impulse response function. Leading evidence for this thesis derives from functional neuroimaging, a methodology ill-suited for detailed assessment of sensory transmission dynamics occurring at the millisecond scale. Electrophysiological assessments of this thesis, however, are sparse and unconvincing. We conducted detailed examination of visual and somatosensory evoked activity using high-density electrical mapping in individuals with autism (N = 20) and precisely matched neurotypical controls (N = 20), recording …

Investigating The Impact Of Unsupervised Feature-Extraction From Multi-Wavelength Image Data For Photometric Classification Of Stars, Galaxies And Qsos, Annika Lindh

Conference papers

Accurate classification of astronomical objects currently relies on spectroscopic data. Acquiring this data is time-consuming and expensive compared to photometric data. Hence, improving the accuracy of photometric classification could lead to far better coverage and faster classification pipelines. This paper investigates the benefit of using unsupervised feature-extraction from multi-wavelength image data for photometric classification of stars, galaxies and QSOs. An unsupervised Deep Belief Network is used, giving the model a higher level of interpretability thanks to its generative nature and layer-wise training. A Random Forest classifier is used to measure the contribution of the novel features compared to a set …

Investigating The Impact Of Green Exercise On Population Health And Well-Being In A Small Community In Ireland:A Novel Approach Using A Natural Laboratory Ecosystem., Nollaig O'Sullivan, Aoife Donnelly, Tadhg Macintyre, Giles Warrington

Articles

Green exercise is defined as undertaking physical activity whilst being directly exposed to nature (Pretty et al., 2005; 2007). Pretty et al. (2003) were among the first wave of researchers to investigate the synergistic benefits of incorporating physical activity and exposure to the natural environment to produce positive psychological affect. Over the past decade, investigations into the possible additive effects on well-being of green exercise and how it can be used as an influential tool to help combat the rising rate of both physical inactivity and non –communicable disease has gained prominence in scientific literature. However, there is still a …

Modelling Random Antibody Adsorption And Immunoassay Activity, Dana Mackey, Eilis Kelly, Robert Nooney

Articles

One of the primary considerations in immunoassay design is optimizing the concentration of capture antibody in order to achieve maximal antigen binding and, subsequently, improved sensitivity and limit of detection. Many immunoassay technologies involve immobilization of the antibody to solid surfaces. Antibodies are large molecules in which the position and accessibility of the antigen-binding site depend on their orientation and packing density. In this paper we propose a simple mathematical model, based on the theory known as random sequential adsorption (RSA), in order to calculate how the concentration of correctly oriented antibodies (active site exposed for subsequent reactions) evolves during …

Towards A Computational Model Of Frame Of Reference Alignment In Swedish Dialogue, Simon Dobnik, Christine Howes, Kim Demaret, John D. Kelleher

Conference papers

In this paper we examine how people negotiate, interpret and repair the frame of reference (FoR) in online text based dialogues discussing spatial scenes in Swedish. We describe work-in-progress in which participants are given different perspectives of the same scene and asked to locate several objects that are only shown on one of their pictures. This task requires participants to coordinate on FoR in order to identify the missing objects. This study has implications for situated dialogue systems.

Ultra-Filtration Of Human Serum For Improved Quantitative Analysis Of Low Molecular Weight Biomarkers Using Atr-Ir Spectroscopy, Franck Bonnier, Helene Blasco, Clement Wasselet, Guillaume Brachet, Renaud Respaud, Luis Felipe Cs. Carvalho, Dominque Bertrand, Mathew J. Baker, Hugh Byrne, Igor Chourpa

Articles

Infrared spectroscopy is a reliable, rapid and cost effective characterisation technique, delivering a molecular finger print of the sample. It is expected that its sensitivity would enable detection of small chemical variations in biological samples associated with disease. ATR-IR is particularly suitable for liquid sample analysis and, although air drying is commonly performed before data collection, just a drop of human serum is enough for screening and early diagnosis. However, the dynamic range of constituent biochemical concentrations in the serum composition remains a limiting factor to the reliability of the technique. Using glucose as a model spike in human serum, …

Synthesis Of Orthogonally Protected Thioamide Dipeptides For Use In Solid-Phase Peptide Synthesis, Fintan Kelleher, Kim Manzor

Articles

Orthogonally protected thioamide-containing dipeptides were efficiently and cleanly prepared from the precursor dipeptides using Curphey’s method (P₄S₁₀, hexamethyldisiloxane (HMDO), reflux, DCM) in 67-96% isolated yield. This was in contrast to the use of Lawesson’s or Berzelius’ reagents where significant issues with reaction non-completion, decomposition and purification were observed. Subsequent clean removal of the dipeptides’ t-butyl ester protecting groups gave thioamide dipeptide acids which were suitable for use in solid-phase peptide synthesis (SPPS).

Fundamentals Of Machine Learning For Neural Machine Translation, John D. Kelleher

Conference papers

This paper presents a short introduction to neural networks and how they are used for machine translation and concludes with some discussion on the current research challenges being addressed by neural machine translation (NMT) research. The primary goal of this paper is to give a no-tears introduction to NMT to readers that do not have a computer science or mathematical background. The secondary goal is to provide the reader with a deep enough understanding of NMT that they can appreciate the strengths of weaknesses of the technology. The paper starts with a brief introduction to standard feed-forward neural networks (what …

The Role Of Perception In Situated Spatial Reference, John D. Kelleher

Conference papers

This position paper set out the argument that an interesting avenue of exploration and study of universals and variation in spatial reference is to address this topic in termsa of the universals in human perception and attention and to explore how these universals impact on spatial reference across cultures and languages.

A Pilot Study Of Comparison Gesture Analysis In Motion Driven Video Games, Fabrizio Valerio Covone, Brian Vaughan, Charlie Cullen

Conference Papers

This study investigates whether there are significant differences in the gestures made by gamers and non-gamers whilst playing commercial games that employ gesture inputs. Specifically, the study focuses on testing a prototype of multimodal capture tool that we used to obtain real-time audio, video and skeletal gesture data. Additionally, we developed an experimental design framework for the acquisition of spatio-temporal gesture data and analysed the vector magnitude of a gesture to compare the relative displacement of each participant whilst playing a game.

Echocardiography Audit On Patients With Hereditary Haemochromatosis, Lorna Doran

Masters

Background: The European Association for the Study of the Liver (EASL) Guidelines for Hereditary Haemochromatosis (HH) refer specifically to symptomatic Homozygous C282Y patients and provide an algorithm for treating such patients who are predisposed to iron overloading. The British Society of Echocardiography does not make provisions for HH patients per se. Cardiac failure is a known complication of severe iron overload although it is atypical. Aim: To retrospectively investigate if an echocardiogram (echo) was warranted in the HH population at Louth County Hospital (LCH) Venesection Clinic based on the current guidelines. Methods: A cohort of 833 HH patients was reviewed …

Investigating The Impact Of Unsupervised Feature-Extraction From Multi-Wavelength Image Data For Photometric Classification Of Stars, Galaxies And Qsos, Annika Lindh

Dissertations

This thesis reviews the current state of photometric classification in Astronomy and identifies two main gaps: a dependence on handcrafted rules, and a lack of interpretability in the more successful classifiers. To address this, Deep Learning and Computer Vision were used to create a more interpretable model, using unsupervised training to reduce human bias.

The main contribution is the investigation into the impact of using unsupervised feature-extraction from multi-wavelength image data for the classification task. The feature-extraction is achieved by implementing an unsupervised Deep Belief Network to extract lower-dimensionality features from the multi-wavelength image data captured by the Sloan Digital …

Short Term Forecasting Of Nitrogen Dioxide (No2) Levels Using A Hybrid Statistical And Air Mass History Modelling Approach, Aoife Donnelly, Owen Naughton, Brian Broderick, Bruce Misstear

Articles

A novel hybrid model has been developed to support the provision of real-time air quality forecasts. Statistical techniques have been applied in parallel with airmass history modelling to provide an efficient and accurate forecasting system with the ability to identify high NO2 events, which tend to be the episodes ofmost significance in Ireland. Airmass history modelling and k-means clustering are used to identify air mass types that lead to high NO2 levels in Ireland. Trajectory matching techniques allow data associated with these air masses to be partitioned during model development. Non-parametric regression (NPR) has been applied to describe nonlinear variations …

Towards A Deep Learning-Based Activity Discovery System, Eoin Rogers, John D. Kelleher, Robert J. Ross

Conference papers

Activity discovery is a challenging machine learning problem where we seek to uncover new or altered behavioural patterns in sensor data. In this paper we motivate and introduce a novel approach to activity discovery based on modern deep learning techniques. We hypothesise that our proposed approach can deal with interleaved datasets in a more intelligent manner than most existing AD methods. We also build upon prior work building hierarchies of activities that capture the inherent ag- gregate nature of complex activities and show how this could plausibly be adapted to work with the deep learning technique we present. Finally, we …

Ga Based Optimal Control For Maximizing Pv Penetration At Transmission, Chittesh Veni Chandran

Student Journal of Energy Research

Utilization of distributed energy resources (DER’s) like photo-voltaic generators, is one of the possible solution for present scenario of energy crisis. Most of the study suggest the implementation of PV power stations at distribution level. In this paper detailed theoretical analyses of the impact of large scale PV on transmission level is analysed. The preliminary section of this paper provides literature review with specifications of IEEE-14 bus network. Two methodology ie, constant load method and maximum loading method is implemented here. A test study is done in IEEE 14 bus to find out the optimal location of solar photo-voltaic generator …

Risk Assessment For Two Multi Terminal Vsc-Hvdc Control Schemes, Roberto Sandano

Student Journal of Energy Research

High Voltage Direct Current (HVDC) connections have been in operation since the 1950s. The vast majority of which are point to point connections and use Line Commutated Converter (LCC) technology. Since the late nineties Voltage Source Converter (VSC) technology has become a feasible choice on HVDC transmission systems [1]. Research is now focused in the development of Multi-terminal (MT)-HVDC system which will facilitate the collection of energy from distant dispersed renewable energy resources and transport this energy to load centres.

Power Quality Improvement In Fuel Cell Based Hybrid Power System Using Statcom, Sandipan Patra

Student Journal of Energy Research

This paper presents the power quality improvement in a microgrid, supplying a nonlinear and unbalanced load using fuzzy logic controller based static synchronous compensator (STATCOM). The microgrid contains a hybrid combination photovoltaic (PV), fuel cell (FC) along with the battery energy storage system (BESS) where a decentralized power sharing algorithm is used to control its power management. Here, STATCOM is used as a compensator for the hybrid system to reduce the harmonics in the voltage and current profile at the point of common coupling (PCC). The current reference is generated taking into account, the active and reactive power to be …

In Vitro Monitoring Of Time And Dose Dependent Cytotoxicity Of Aminated Nanoparticles Using Raman Spectroscopy, Esen Efeoglu, Alan Casey, Hugh Byrne

Articles

No abstract provided.

A Model For Attention-Driven Judgements In Type Theory With Records, Simon Dobnik, John D. Kelleher

Conference papers

This paper makes three contributions to the discussion on the applicability of Type Theory with Records (TTR) to embodied dialogue agents. First, it highlights the problem of type assignment or judgements in practical implementations which is resource intensive. Second, it presents a judgement control mechanism, which consists of grouping of types into clusters or states by their thematic relations and selection of types following two mechanisms inspired by the Load Theory of selective attention and cognitive control (Lavie et al., 2004), that addresses this problem. Third, it presents a computational framework, based on Bayesian inference, that offers a basis for …

Spectroscopic Studies Of Anthracyclines: Structural Characterization And In Vitro Tracking, Zeineb Farhane, Hugh Byrne, Malgorzata Baranska

Articles

A broad spectroscopic characterization, using ultraviolet-visible (UV-vis) and Fourier transform infrared absorption as well as Raman scattering, of two commonly used anthracyclines antibiotics (DOX) daunorubicin (DNR), their epimers (EDOX, EDNR) and ten selected analogs is presented. The paper serves as a comprehensive spectral library of UV-vis, IR and Raman spectra of anthracyclines in the solid state and in solution. The particular advantage of Raman spectroscopy for the measurement and analysis of individual antibiotics is demonstrated. Raman spectroscopy can be used to monitor the in vitro uptake and distribution of the drug in cells, using both 488 nm and 785 nm …

Screening The Low Molecular Weight Fraction Of Human Serum Using Atr-Ir Spectroscopy, Franck Bonnier, Matthew J. Baker, Hugh Byrne

Articles

Vibrational spectroscopic techniques can detect small variations in molecular content, linked with disease, showing promise for screening and early diagnosis. Biological fluids, particularly blood serum, are potentially valuable for diagnosis purposes. The so-called Low Molecular Weight Fraction (LMWF) contains the associated peptidome and metabolome and has been identified as potentially the most relevant molecular population for disease-associated biomarker research. Although vibrational spectroscopy can deliver a specific chemical fingerprint of the samples, the High Molecular Weight Fraction (HMWF), composed of the most abundant serum proteins, strongly dominates the response and ultimately makes the detection of minor spectral variations a challenging task. …

A Comparison Of Catabolic Pathways Induced In Primary Macrophages By Pristine Single Walled Carbon Nanotubes And Pristine Graphene, Caroline More, Jennifer Mcintyre, Luke O'Neill, Hugh Byrne

Articles

Understanding the correlation between the physico-chemical properties of carbonaceous nanomaterials and how these properties impact on cells and subcelluar mechanisms is critical to their risk assessment and safe translation into newly engineered devices. Here the toxicity, uptake and catabolic response of primary human macrophages to pristine graphene (PG) and pristine single walled carbon nanotubes (pSWCNT) are explored, compared and contrasted. The nanomaterial toxicity was assessed using three complementary techniques (live-dead assay, real time impedance technique and confocal microscopic analysis), all of which indicated no signs of acute cytotoxicity in response to PG or pSWCNT. Transmission electron microscopy (TEM) demonstrated that …

The Evaluation And Implementation Of Magnetic Fields For Large Strain Uniaxial And Biaxial Cyclic Testing Of Magnetorheological Elastomers., Dave Gorman, Niall Murphy, Ray Ekins, Stephen Jerrams

Articles

Magnetorheological Elastomers (MREs) are “smart” materials whose physical properties are altered by the application of magnetic fields. In previous studies the properties of MREs have been evaluated under a variety of conditions, however little attention has been paid to the recording and reporting of the magnetic fields used in these tests [1]. Currently there is no standard accepted method for specifying the magnetic field applied during MRE testing. This study presents a detailed map of a magnetic field applied during MRE tests as well as providing the first comparative results for uniaxial and biaxial testing under high strain fatigue test …

Theoretical Modeling Of The Effect Of Polymer Chain Immobilization Rates On Holographic Recording In Photopolymers, Dana Mackey, Paul O'Reilly, Izabela Naydenova

Articles

This paper introduces an improved mathematical model for holographic grating formation in an acrylamide-based photopolymer, which consists of partial differential equations derived from physical laws. The model is based on the two-way diffusion theory of \cite{izabela}, which assumes short polymer chains are free to diffuse, and generalizes a similar model presented in \cite{josab} by introducing an immobilization rate governed by chain growth and cross-linking. Numerical simulations were carried out in order to investigate the behaviour of the photopolymer system for short and long exposures, with particular emphasis on the effect of recording parameters (such as illumination frequency and intensity), as …

Photocatalytic Properties Of G-C3n4–Tio2 Heterojunctions Under Uv And Visible Light Conditions, Rachel Fagan, Declan Mccormack, Steven J. Hinder, Suresh Pillai

Articles

Graphitic carbon nitride (g-C3N4) and titanium dioxide (TiO2) were chosen as a model system to investigate photocatalytic abilities of heterojunction system under UV and visible light conditions. The use of g-C3N4 has been shown to be effective in the reduction in recombination through the interaction between the two interfaces of TiO2 andg-C3N4. A simple method of preparing g-C3N4 through the pyrolysis of melamine was employed, which was then added to undoped TiO2 material to form the g-C3N4–TiO2 system. These materials were then fully characterized by X-ray diffraction (XRD), Brunauer Emmett Teller (BET), and various spectroscopic techniques including Raman, X-ray photoelectron …

Evaluation Of Cytotoxicity Profile And Intracellular Localisation Of Doxorubicin-Loaded Chitosan Nanoparticles, Gabriele Dadalt Souto, Zeineb Farhane, Esen Efeoglu, Alan Casey, Jennifer Mcintyre, Hugh Byrne

Articles

In the emerging field of nanomedicine, targeted delivery of nanoparticle encapsulated active pharmaceutical ingredients (API) is seen as a potential significant development, promising improved pharmacokinetics and reduced side effects. In this context, understanding the cellular uptake of the nanoparticles and subsequent subcellular distribution of the API is of critical importance. Doxorubicin (DOX) was encapsulated within chitosan nanoparticles to investigate its intracellular delivery in A549 cells in vitro. Unloaded (CS-TPP) and doxorubicin-loaded (DOX-CS-TPP) chitosan nanoparticles were characterised for size (473±41 nm), polydispersity index (0.3±0.2), zeta potential (34±4 mV), drug content (76±7 µM) and encapsulation efficiency (95±1%). The cytotoxic response to …

Novel Mitochondrial Complex I Inhibitors Restore Glucose-Handling Abilities Of High-Fat Fed Mice, Darren Martin, Siobhan Leonard, Robert Devine, Clara Redondo, Gemma Kinsella, Conor Breen, Victoria Mceneaney, Mary Rooney, Tim Munsey, Richard Porter, Asipu Sivaprasadarao, John Stephens, John Findlay

Articles

Metformin is the main drug of choice for treating type 2 diabetes, yet the therapeutic regimens and side effects of the compound are all undesirable and can lead to reduced compliance. The aim of this study was to elucidate the mechanism of action of two novel compounds which improved glucose handling and weight gain in mice on a high-fat diet. Wildtype C57Bl/6 male mice were fed on a high-fat diet and treated with novel, anti-diabetic compounds. Both compounds restored the glucose handling ability of these mice. At a cellular level, these compounds achieve this by inhibiting complex I activity in …

Modification Of The In Vitro Uptake Mechanism And Anti-Oxidant Levels In Hacat Cells And Resultant Changes To Toxicity And Oxidative Stress Of G4 And G6 Poly (Amido Amine) Dendrimer Nanoparticles, Marcus A. Maher, Hugh Byrne

Articles

The mechanism of cellular uptake by endocytosis and subsequent oxidative stress has been identified as the paradigm for the toxic response of cationically surface charged nanoparticles. In an attempt to circumvent the process, the effect of increased cellular membrane permeability on the uptake mechanisms of poly (amidoamine) dendrimers generation 4 (G4) and 6 (G6) in vitro was investigated. Immortalised, non-cancerous human keratinocyte (HaCaT) cells were treated with DL-Buthionine-(S,R)-sulfoximine (BSO). Active uptake of the particles was monitored using fluorescence microscopy to identify and quantify endosomal activity and resultant oxidative stress, manifest as increased levels of reactive oxygen species, monitored using the …