Physical Sciences and Mathematics Commons^™

Hamiltonian Dynamics Of Cosmological Quintessence Models, Rossen Ivanov, Emil Prodanov

Articles

The time-evolution dynamics of two nonlinear cosmological real gas models has been reexamined in detail with methods from the theory of Hamiltonian dynamical systems. These examples are FRWL cosmologies, one based on a gas, satisfying the van der Waals equation and another one based on the virial expansion gas equation. The cosmological variables used are the expansion rate, given by the Hubble parameter, and the energy density. The analysis is aided by the existence of global first integral as well as several special (second) integrals in each case. In addition, the global first integral can serve as a Hamiltonian for …

Dielectric Materials With Memory Ii: Free Energies In Non- Magnetic Materials, Scott Glascow, John Murrough Golden

Articles

An isothermal theory of free energies and free enthalpies, corresponding to linear constitutive relations with memory, is presented for isotropic non-magnetic materials. This is a second paper, following recent work on a general tensor theory of isothermal dielectrics and on the form of the minimum free energy. Both papers are based on continuum thermodynamics. For a standard choice of relaxation function, the minimum and maximum free energies are given explicitly, using a method previously developed in a mechanics context. Also, a new family of intermediate free energy functionals is derived for dielectrics. All these are solutions of a constrained optimization …

Disrupted Superior Collicular Activity May Reveal Cervical Dystonia Disease Pathomechanisms, Eavan Mc Govern, Owen Killian, Shruti Narasimham, Brendan T. Quinlivan, John Butler, Rebecca B. Beck, Ines M. Beiser, Laura W. Williams, Ronan P.M. Killeen, Michael A. Farrell, Seán O'Riordan, Richard B. Reilly, Michael J. Hutchinson

Articles

Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected …

Disrupted Superior Collicular Activity May Reveal Cervical Dystonia Disease Pathomechanisms, Eavan M. Mcgovern, Owen Killian, Shruti Narashimham, Brendan Quinlivan, John Butler, Rebecca Beck, Ines Beiser, Laura W. Williams, Ronan P. Killeen, Michael Farrell, Sean O'Riordan, Richard B. Reilly, Michael Hutchinson

Articles

Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected …

Disrupted Superior Collicular Activity May Reveal Cervical Dystonia Disease Pathomechanisms, Eavan Mcgovern, Owen Killian, Shruti Narasimham, Brendan Quinlivan, John Butler, Rebecca Beck, Ines Beiser, Laura Williams, Ronan P. Kileen, Michael Farrell, Sean O'Riordan, Richard B. Reilly, Michael Hutchinson

Articles

Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures afecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in afected patients and in relatives harbouring a disease-specifc endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unafected frst-degree relatives with abnormal temporal discrimination, 16 unafected …

On Integrable Wave Interactions And Lax Pairs On Symmetric Spaces, Vladimir S. Gerdjikov, Georgi G. Grahovski, Rossen Ivanov

Articles

No abstract provided.

A Comparison Of Stimulus Presentation Methods In Temporal Discrimination Testing, Eavan M. Mcgovern, John Butler, Ines Beiser, Laura Williams, Brendan Quinlivan, Shruti Narasiham, Rebecca Beck, Sean O'Riordan, Richard B. Reilly, Michael Hutchinson

Articles

The temporal discrimination threshold (TDT) is the shortest time interval at which an individual detects two stimuli to be asynchronous (normal  =  30-50 ms). It has been shown to be abnormal in patients with disorders affecting the basal ganglia including adult onset idiopathic focal dystonia (AOIFD). Up to 97% of patients have an abnormal TDT with age- and sex-related penetrance in unaffected relatives, demonstrating an autosomal dominant inheritance pattern. These findings support the use of the TDT as a pre-clinical biomarker for AOIFD. The usual stimulus presentation method involves the presentation of progressively asynchronous stimuli; when three sequential stimuli are …

R-Hopfian And L-Co-Hopfian Abelian Groups, Brendan Goldsmith, Katao Gong

Articles

The notions of Hopfian and co-Hopfian groups are well known in both non-commutative and Abelian group theory. In this work we begin a systematic investigation of natural generalizations of these concepts and, in the case of Abelian p-groups, give a complete characterization of the generalizations in terms of the original concepts.

Evaluation Of The Effect Of Plasma Treatment Frequency On The Activation Of Polymer Particles, Hisham Abourayana, Vladimir Milosavljevic, Peter Dobbyn, Denis Dowling

Articles

This study investigates the influence of treatment frequency (1–150 kHz) on the atmospheric plasma activation of both silicone and polyethylene terephthalate (PET) particles. These polymer particles with diameters in the range 3–5 mm, were treated using either helium or helium/oxygen gas mixtures, in a barrel atmospheric plasma system. The level of polymer particles activation was monitored using water contact angle measurements. The effect of plasma treatment frequency on barrel heating was monitored using an infrared thermographic camera, the maximum barrel temperature after 15 min treatment was found to be 98 °C at a frequency of 130 kHz. Optical emission spectroscopy …

Epidemiological, Clinical And Genetic Aspects Of Adult Onset Isolated Focal Dystonia In Ireland, L. Williams, E. Mcgovern, O. Kimmich, A. Molloy, I. Beiser, John Butler, F. Molloy, P. Logan, D.G. Healy, T. Lynch, R. Walsh, L. Cassidy, P. Moriarty, H. Moore, T. Mcswiney, C. Walsh, S. O'Riordan, M. Hutchinson

Articles

Background: Adult onset idiopathic isolated focal dystonia presents with a number of phenotypes. Reported prevalence rates vary considerably; well-characterized cohorts are important to our understanding of this disorder.

Aim: To perform a nationwide epidemiological study of adult onset idiopathic isolated focal dystonia in the Republic of Ireland.

Methods: Patients with adult onset idiopathic isolated focal dystonia were recruited from multiple sources. Diagnosis was based on assessment by a neurologist with an expertise in movement disorders. When consent was obtained, a number of clinical features including family history were assessed.

Results: On the prevalence date there were 592 individuals in Ireland …

Development And Characterisation Of A Bath-Based Vertical Blackbody Cavity Calibration Source For The Range −30 °C To 150 °C, Sam Boles, Igor Pušnik, Dubhaltach Mac Lochlainn, David Fleming, Izabela Naydenova, Suzanne Martin

Articles

Industrial use of Radiation Thermometers (RTs) is becoming increasingly common due to the perceived advantages and wide market availability. Blackbody Cavity Radiation Sources (BCRSs) are typically used for calibration of these instruments, and these cavities are oriented horizontally in most cases. For BCRSs based in thermal baths, this necessitates the use of custom-built baths with side openings. This paper presents a unique design of vertical bath-based BCRS that may be immersed in conventional calibration baths without modifications to the baths. The method, results, and analysis of an international comparison comparing this vertical BCRS, standard horizontal BCRSs, and a previous iteration …

Data Analytics In Performance Of Kick-Out Distribution And Effectiveness In Senior Championship Football In Ireland, Roisin Donnelly, Darragh Daly

Articles

n recent years, data analytics has been a growing phenomenon in many fields, including sport, and there has been an increased focus on how technology will impact the work of coaching andperformance professionals. This paper provides a reflection of the use of data analytics within the Gaelic Athletic Association’s (GAA) football coaching practice in Ireland, and evaluates for coaches how to enhance kick- out distribution and effectiveness. Specifically, the study aimed to dissect and analyse kick- out strategies to assess from a coaching perspective, the impact on distribution andeffectiveness. The research is a …

Isolation And Spectroscopic Characterization Of Zn(Ii), Cu(Ii), And Pd(Ii) Complexes Of 1,3,4-Thiadiazole-Derived Ligand, Dariusz Karcz, Arkadiusz Matwijczuk, Bozena Boron, Bernadette Creaven, Leszek Fiedor, Andrzej Niewiadomy, Mariusz Gagos

Articles

A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv–vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 …

Extraction And Quantification Of Sinapinic Acid From Irish Rapeseed Meal And Assessment Of Angiotensin-I Converting Enzyme (Ace-I) Inhibitory Activity, Leah Quinn, Steven Gray, Steve Meaney, Stephen Finn, Padraig Mcloughlin, Maria Hayes

Articles

Phenolic compounds, including phenolic acids, are known to play a protective role against the development of cardiovascular disease. The aim of this work was to generate a phenolic acid extract from Irish rapeseed meal, to determine the quantity of sinapinic acid (SA) in this fraction and to assess the ability of this fraction to inhibit the enzyme angiotensin-I converting enzyme (ACE-I; EC 3.4.15.1). A crude phenolic extract (fraction 1), free phenolic acid containing extract (fraction 2), and an extract containing phenolic acids liberated from esters (fraction 3) were generated from Irish rapeseed meal using a methanol:acetone:water solvent mixture (7:7:6). The …

Information Hiding With Data Diffusion Using Convolutional Encoding For Super-Encryption, Jonathan Blackledge, Paul Tobin, J. Myeza, C.M. Adolfo

Articles

The unification of data encryption with information hiding methods continues to receive significant attention because of the importance of protecting encrypted information by making it covert. This is because one of the principal limitations in any cryptographic system is that encrypted data flags the potential importance of the data (i.e. the plaintext information that has been encrypted) possibly leading to the launch of an attack which may or may not be successful. Information hiding overcomes this limitation by making the data (which may be the plaintext or the encrypted plaintext) imperceptible, the security of the hidden information being compromised if …

Enhancement Of Dielectric Properties With The Addition Of Bromine And Dopamine Modified Barium Titanate Particles To Silicone Rubber, Liang Jiang, David Kennedy, Stephen Jerrams, Tony Betts

Articles

Dual-coated barium titanate (BT) particles were prepared using dopamine (DP) in conjunction with bromine (Br) in order to enhance the dielectric constant of silicone rubber (SR) composites containing evenly distributed BT particles. The results showed that both DP and Br were deposited on the BT particles. The dielectric constant of the SR/BT composite was significantly increased from 3.6 to 4.7 at 1 kHz with the addition of BT modified with dopamine (DP–BT). Moreover, the dielectric constant further rose to 4.9 at 1 kHz when the DP–BT particle was grafted with bromine (Br–DP–BT).

Electromechanical Instability In Silicone-And Acrylate-Based Dielectric Elastomers, Liang Jiang, Yanfen Shou, Shaojuan Chen, Jianwei Ma, Tony Betts, Stephen Jerrams

Articles

Electromechanical instability (EMI) is regarded as a significant factor in preventing dielectric elastomers (DEs) fromachieving large voltage-induced deformations. In this study, the strain-stiffening effect was used to control the occurrence of EMI in DEs. The results show that the stretching ratio required to provide a feasible strain-stiffening effect in silicone rubber (SR) was smaller than that needed for a commercial DE material, VHB 4910. The experimental data were compared with currently used models for the simulation of EMI in DEs. We found that EMI could be eliminated in the deformation of these elastomers when pre-stretching was used. Through the application …

A Conceptual Framework For A Software Development Process Based On Computational Thinking, Catherine Higgins, Ciaran O'Leary, Orla Hanratty, Fredrick Mtenzi

Articles

A software development process is a mechanism for problem solving to help software developers plan, design and structure the development of software to solve a problem. Without a process to guide the structured evolution of a solution, it is extremely likely that at least some aspect of the resulting software will be omitted or incorrectly implemented. Even though the importance of utilising a software process for solving problems is accepted in the business and academic communities, it is a topic that is addressed very lightly (if at all) in most freshman undergraduate computing courses with most courses focussing on programming …

Quantification Of Copper Content With Laser Induced Breakdown Spectroscopy As A Potential Indicator Of Offal Adulteration In Beef, Maria Piedad Casado-Gavalda, Yash Dixit, David Geulen, Raquel Cama-Moncunill, Xavier Cama-Moncunill, Maria Markiewicz-Keszycka, Patrick J. Cullen, Carl Sullivan

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Laser induced breakdown spectroscopy (LIBS) is an emerging technique in the field of food analysis which provides various advantages such as minimal sample preparation, chemical free, rapid detection, provision of spatial information and portability. In this study, LIBS was employed for quantitative analysis of copper content in minced beef samples spiked with beef liver over three independent batches. Copper content was determined with graphite furnace atomic absorption spectroscopy (GFAAS) in order to obtain reference values for modelling. Partial least square regression (PLSR) was performed to build a calibration and validation model. A calibration model with a high Rcv2 of 0.85 …

Cybersecurity Stovepiping, David Thaw

Articles

Most readers of this Article probably have encountered – and been frustrated by – password complexity requirements. Such requirements have become a mainstream part of contemporary culture: "the more complex your password is, the more secure you are, right?" So the cybersecurity experts tell us… and policymakers have accepted this "expertise" and even adopted such requirements into law and regulation.

This Article asks two questions. First, do complex passwords actually achieve the goals many experts claim? Does using the password "Tr0ub4dor&3" or the passphrase "correcthorsebatterystaple" actually protect your account? Second, if not, then why did such requirements become so widespread? …

Ancient Worries And Modern Fears: Different Roots And Common Effects Of U.S. And Eu Privacy Regulation, David Thaw, Pierluigi Perri

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Much legal and technical scholarship discusses the differing views of the United States and European Union toward privacy concepts and regulation. A substantial amount of effort in recent years, in both research and policy, focuses on attempting to reconcile these viewpoints searching for a common framework with a common level of protection for citizens from both sides of Atlantic. Reconciliation, we argue, misunderstands the nature of the challenge facing effective cross-border data flows. No such reconciliation can occur without abdication of some sovereign authority of nations, that would require the adoption of an international agreement with typical tools of international …

A Review Of The Recommendations Governing Quality Assurance Of Ultrasound Systems Used For Guidance In Prostate Brachytherapy, Andrea Jane Doyle, Deirdre King, Jacinta Browne

Articles

Ultrasound guided brachytherapy for the treatment of prostate cancer has become a routine treatment option, due to many benefits including patient recovery and dose localisation [1]; however it is not clear whether the standards which govern the image quality for these systems are adequate. Upon review of the recommended standards for ultrasound systems used in prostate brachytherapy procedures, the recommended tests do not appear to be specific to the clinical application of ultrasound guided prostate brachytherapy. Rather they are generic and similar to those recommended for other clinical applications such as general abdominal scanning [2]. Furthermore, there is growing evidence …

Linking Atr-Ftir And Raman Features To Phenolic Extractability And Other Attributes In Grape Skin, Hugh Byrne, Abigain Rooney, Julio Nogales-Bueno, Jose Miguel Hernandez-Hierro, Francisco Jose Heredia

Articles

The importance of wine phenolics on the sensory characteristic of red wines is well-known. Therefore, it is necessary to control the extractability of phenolic compounds from grape skins, which depends significantly on grape ripeness and hence, on cell wall degradation.

In the present study, attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectra of grape skin have been recorded. Then, these spectral matrices have been studied and the main spectral features have been linked to extractabilities of phenolic compounds (anthocyanins, flavanols and total phenols). Moreover, spectral differences between external and internal grape skin surfaces also have been studied.

It …

Determination Of Spectral Markers Of Cytotoxicity And Genotoxicity Using In Vitro Raman Microspectroscopy: Cellular Responses To Polyamidoamine Dendrimer Exposure, Esen Efeoglu, Alan Casey, Hugh Byrne

Articles

Although consumer exposure to nanomaterials is ever increasing, with potential increased applications in areas such as drug and/or gene delivery, contrast agents and diagnosis, determination of cyto- and geno- toxic effect of nanomaterials on human health and the environment still remains challenging. Although many techniques have been established and adapted to determine the cytotoxicity and genotoxicity of nano-sized materials, these techniques remain limited by the number of assays required, total cost, use of labels and they struggle to explain the underlying interaction mechanisms. In this study, Raman microspectroscopy is employed as an in vitro label free high content screening technique …

A Natural, Calcium-Rich Marine Multi-Material Complex Preserves Bone Structure, Composition And Strength In An Ovariectomized Rat Model Of Osteoporosis, Orlaith Brennan, Joseph Sweeney, Brian O'Meara, Amro Widaa, Franck Bonnier, Hugh Byrne, Denis O'Gorman, Fergal O'Brien

Articles

Calcium supplements are used as an aid in the prevention of osteopenia and osteoporosis and also for the treatment of patients when used along with medication. Many of these supplements are calcium carbonate based. This study compared a calcium-rich, marine multi-mineral complex (Aquamin) to calcium carbonate in an ovariectomised rat model of osteoporosis in order to assess Aquamin’s efficacy in preventing the onset of bone loss. Animals were randomly assigned to either non-ovariectomy control (Control), ovariectomy (OVX) plus calcium carbonate, ovariectomy plus Aquamin or ovariectomy plus Aquamin delay where Aquamin treatment started 8 weeks post OVX. At the end of …

Abusive Text Detection Using Neural Networks, Hao Chen, Susan Mckeever, Sarah Jane Delany

Articles

Neurall network models have become increasingly popular for text classification in recent years. In particular, the emergence of word embeddings within deep learning architecture has recently attracted a high level of attention amongst researchers.

A Software Development Process For Freshman Undergraduate Students, Catherine Higgins, Fredrick Mtenzi, Ciaran O'Leary, Orla Hanratty, Claire Mcavinia

Articles

This conceptual paper presents work which is part of an ongoing research project into the design of a software development process aimed at freshman, undergraduate computing students. The process of how to plan and develop a solution is a topic that is addressed very lightly in many freshman, undergraduate courses which can leave novices open to developing habit-forming, maladaptive cognitive practices. The conceptual software development process described in this paper has a learning process at its core which centres on declarative knowledge (in the form of threshold concepts) and procedural knowledge (in the form of computational thinking skills) scaffolding freshman …

Pilot Investigation Into The Use Of An Anthropomorphic Breast Sonography Phantom As A Training And Assessment Tool, Jacinta Browne, Louise Cannon, Ronan Mcdermott, Max Ryan, Andrew J. Fagan

Articles

A device for the training and quantitative assessment of the competency of trainee radiologists in the technically challenging area of breast sonography was developed and evaluated. Currently, suitable commercially available devices are lacking, and there is a growing realization that the reliance on direct exposure to patients for learning may not represent best practice from either the trainees' or patients' perspective. Three devices (PI, PII and PIII) were designed to produce very realistic sonographic images of breast morphology with a range of embedded pathologies. The pilot evaluation used a case study research design to evaluate the role of the anthropomorphic …

Mind The Gap: An Initial Analysis Of The Transition Of A Second Level Curriculum Reform To Higher Education, Michael Carr, Fiona Faulkner, Cormac Breen, Mark Prendergast

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This article details an initial analysis of the transition of a second level curriculum reform to higher education in Ireland. The reform entitled ‘Project Maths’ involved changes to what second level students learn in mathematics, how they learn it, and how they are assessed. Changes were rolled out nationally on a phased basis in September 2010. Students who were taught and assessed through the new curriculum first entered third level education in September 2012. It is important that third level mathematics lecturers are aware of the changes to the curriculum since certain topics such as vectors and matrices are no …

Subjective Usability, Mental Workload Assessments And Their Impact On Objective Human Performance, Luca Longo

Articles

Self-reporting procedures and inspection methods have been largely employed in the fields of interaction and web-design for assessing the usability of interfaces. However, there seems to be a propensity to ignore features related to end-users or the context of application during the usability assessment procedure. This research proposes the adoption of the construct of mental workload as an additional aid to inform interaction and web-design. A user-study has been performed in the context of human-web interaction. The main objective was to explore the relationship between the perception of usability of the interfaces of three popular web-sites and the mental workload …