Digital Commons Network^™

Relating Group Size And Posting Activity Of An Online Community Of Financial Investors: Regularities And Seasonal Patterns, P. Racca, R. Casarin, Pierpaolo Dondio, F. Squazzoni

Articles

Group size can potentially affect collective activity and individual propensity to contribute to collective goods. Mancur Olson, in his Logic of Collective Action, argued that individual contribution to a collective good tends to be lower in groups of large size. Today, online communication platforms represent an interesting ground to study such collaborative dynamics under possibly different conditions (e.g., lower costs related to gather and share information). This paper examines the relationship between group size and activity in an online financial forum, where users invest time in sharing news, analysis and comments with other investors. We looked at about 24 million …

Pseudorehearsal In Actor-Critic Agents With Neural Network Function Approximation, Vladimir Marochko, Leonard Johard, Manuel Mazzara, Luca Longo

Articles

Catastrophic forgetting has a significant negative impact in reinforcement learning. The purpose of this study is to investigate how pseudorehearsal can change performance of an actor-critic agent with neural-network function approximation. We tested agent in a pole balancing task and compared different pseudorehearsal approaches. We have found that pseudorehearsal can assist learning and decrease forgetting.

Towards Dynamic Interaction-Based Reputation Models, Almas Melnikov, Manuel Mazzara, Victor Rivera, Jooyoung Lee, Luca Longo

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In this paper, we investigate how dynamic properties of reputation can influence the quality of users’ ranking. Reputation systems should be based on rules that can guarantee high level of trust and help identify unreliable units. To understand the effectiveness of dynamic properties in the evaluation of reputation, we propose our own model (DIB-RM) that utilizes three factors: forgetting, cumulative, and activity period. In order to evaluate the model, we use data from StackOverflow which also has its own reputation model. We estimate similarity of ratings between DIB-RM and the StackOverflow reputation model to test our hypothesis. We use two …

The Federal Law Of Property: The Case Of Inheritance Disclaimers And Tenancy By The Entireties, David G. Carlson

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The Supreme Court has issued two disturbing tax opinions which disrupt the notion that “property” (when used in federal statutes) refers to state-law notions. In Drye v. United States, the Supreme Court pierced the Arkansas fiction that inheritance disclaimers are retrospective in effect. Thus the Internal Revenue could claim that a tax lien attached to the pre-disclaimer inheritance. Disclaimer could not defeat this lien. In United States v. Craft, the Supreme Court pierced the Michigan fiction that a tenancy by the entireties does not belong to the individual spouses but, rather, the a corporate “marital” entity that is a separate …

Finding Lost & Found: Designer’S Notes From The Process Of Creating A Jewish Game For Learning, Owen Gottlieb

Articles

This article provides context for and examines aspects of the design process of a game for learning. Lost & Found (2017a, 2017b) is a tabletop-to-mobile game series designed to teach medieval religious legal systems, beginning with Moses Maimonides’ Mishneh Torah (1180), a cornerstone work of Jewish legal rabbinic literature. Through design narratives, the article demonstrates the complex design decisions faced by the team as they balance the needs of player engagement with learning goals. In the process the designers confront challenges in developing winstates and in working with complex resource management. The article provides insight into the pathways the team …

Into The Deep: The Role Of Paradigms In Understanding Engineering Education For Sustainable Development, Iacovos Nicolaou, Eddie Conlon, Brian Bowe

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This article presents summary findings of a mixed methods research project exploring the provision of education for sustainable development (SD) in seven Irish engineering degree programmes. Drawing on Sterling’s (2004) iceberg metaphor and Critical Realism it seeks to identify the underlying socio-cultural barriers preventing a holistic integration of SD in engineering education. It argues that the current focus is predominantly on the environmental dimension of SD and that there are a set of reinforcing mechanisms facilitating the provision of disciplinary education aimed at producing technically proficient, employable graduates in which the social dimension of SD is marginalised. This is underwritten …

Facing The Sun, Frank Prendergast, Muiris O'Sullivan, Ken Williams, Gabriel Cooney

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December 2017 marked 50 years since archaeologist Michael J. O’Kelly first observed the solar illumination of the burial chamber in the Neolithic passage tomb at Newgrange during the period of the winter solstice. O’Kelly subsequently recorded direct sunlight entering Newgrange through the ‘especially contrived slit which lies under the roof-box at the outer end of the passage roof’ on 21 December 1969. The discovery of this historic phenomenon, dating back over 5,000 years, captured the public interest and imagination at that time and ever since. In this major article published in the Winter 2017 edition of Archaeology Ireland (date of …

Probability Models And Compounding, David L. Farnsworth, James E. Marengo

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We present the case that the ideas contained in a particular sequence of formulas are important in probability and statistics. The synthesis offered by the concepts in the sequence can be very valuable. Facility with this sequence and its underpinnings should be in the skill set of anyone who uses or studies probability or statistics. For illustrative purposes, we give applications to mixture distributions and Bayesian analyses.

Mode-Sum Prescription For Vacuum Polarization In Black Hole Spacetimes In Even Dimensions, Peter Taylor, Cormac Doran

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We present a mode-sum regularization prescription for computing the vacuum polarization of a scalar field in static spherically symmetric black hole spacetimes in even dimensions. This is the first general and systematic approach to regularized vacuum polarization in higher even dimensions, building upon a previous scheme we developed for odd dimensions. Things are more complicated here since the even-dimensional propagator possesses logarithmic singularities which must be regularized. However, in spite of this complication, the regularization parameters can be computed in closed form in arbitrary even dimensions and for arbitrary metric function f(r). As an explicit example of our method, we …

Treating Wrongs As Wrongs: An Expressive Argument For Tort Law, Scott Hershovitz

Articles

The idea that criminal punishment carries a message of condemnation is as commonplace as could be. Indeed, many think that condemnation is the mark of punishment, distinguishing it from other sorts of penalties or burdens. But for all that torts and crimes share in common, nearly no one thinks that tort has similar expressive aims. And that is unfortunate, as the truth is that tort is very much an expressive institution, with messages to send that are different, but no less important, than those conveyed by the criminal law. In this essay, I argue that tort liability expresses the judgment …

Development Of The Central Dogma Concept Inventory (Cdci) Assessment Tool, Dina L. Newman, Christopher W. Snyder, J. Nick Fisk, Leslie Kate Wright

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Scientific teaching requires scientifically constructed, field-tested instruments to accurately evaluate student thinking and gauge teacher effectiveness. We have developed a 23-question, multiple select–format assessment of student understanding of the essential concepts of the central dogma of molecular biology that is appropriate for all levels of undergraduate biology. Questions for the Central Dogma Concept Inventory (CDCI) tool were developed and iteratively revised based on student language and review by experts. The ability of the CDCI to discriminate between levels of understanding of the central dogma is supported by field testing (N = 54), and large-scale beta testing (N = …

A Mathematical Analysis Of Drug Dissolution In The Usp Flow Through Apparatus, David Mcdonnell, Deirdre M. D'Arcy, Lawrence J. Crane, Brendan Redmond

Articles

This paper applies boundary layer theory to the process of drug dissolution in the USP (United States Pharmacopeia) Flow Through Apparatus. The mass transfer rate from the vertical planar surface of a compact within the device is examined. The theoretical results obtained are then compared with those of experiment. The paper also examines the effect on the dissolution process caused by the interaction between natural and forced convection within the apparatus and the introduction of additional boundaries.

The Value Of Instability: An Investigation Of Intra-Subject Variability In Brain Activity Among Obese Adolescent Girls, Lance O. Bauer, Rebecca J. Houston

Articles

BACKGROUND: The present study investigated the value of intra-subject variability (ISV) as a metric for revealing differences in cognition and brain activation associated with an obese versus lean body mass.

METHODS: Ninety-six adolescents with a lean body mass (BMI %-ile = 5-85), and 92 adolescents with an obese body mass (BMI %-ile >=95), performed two tasks (Stroop and Go/NoGo) challenging response inhibition skills. The standard deviations and averages of their reaction time and P300 electroencephalographic responses to task stimuli were computed across trials.

RESULTS: During the Go/NoGo task, the reaction times of subjects with an obese body mass were more …

K-Bit-Swap: A New Operator For Real-Coded Evolutionary Algorithms, Aram Ter-Sarkisov, Stephen Marsland

Articles

There has been a variety of crossover operators proposed for Real-Coded Genetic Algorithms (RCGAs), which recombine values from the same location in pairs of strings. In this article we present a recombination operator for RC- GAs that selects the locations randomly in both parents, and compare it to mainstream crossover operators in a set of experiments on a range of standard multidimensional optimization problems and a clustering problem. We present two variants of the operator, either selecting both bits uniformly at random in the strings, or sampling the second bit from a normal distribution centered at the selected location in …

Advances In Diamond Nanofabrication For Ultrasensitive Devices, Stefania Castelletto, Lorenzo Rosa, Jonathan Blackledge, Mohammed Zaher Al Abri, Albert Boretti

Articles

This paper reviews some of the major recent advances in single-crystal diamond nanofabrication and its impact in nano- and micromechanical, nanophotonics and optomechanical components. These constituents of integrated devices incorporating specific dopants in the material provide the capacity to enhance the sensitivity in detecting mass and forces as well as magnetic field down to quantum mechanical limits and will lead pioneering innovations in ultrasensitive sensing and precision measurements in the realm of the medical sciences, quantum sciences and related technologies.

The Evaluation Of The Effect Of Strain Limits On The Physical Properties Of Magnetorheological Elastomers Subjected To Uniaxial And Biaxial Cyclic Testing., 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 a previous study by the authors [1], variations in the physical properties of MREs have been evaluated when subjected to a range of magnetic field strengths for both uniaxial and biaxial cyclic tests. By applying the same magnetic field to similar samples, this paper investigates the effect of both the upper strain limit and the strain amplitude on the properties of MREs subjected to cyclic fatigue testing. As the magnetorheological (MR) effect is due to the dipole-dipole interactions of the …

A Geometric Derivation Of The Irwin-Hall Distribution, James E. Marengo, Lucas Stefanic, David L. Farnsworth

Articles

The Irwin-Hall distribution is the distribution of the sum of a finite number of independent identically distributed uniform random variables on the unit interval. Many applications arise since round-off errors have a transformed Irwin-Hall distribution and the distribution supplies spline approximations to normal distributions. We review some of the distribution’s history. The present derivation is very transparent, since it is geometric and explicitly uses the inclusion-exclusion principle. In certain special cases, the derivation can be extended to linear combinations of independent uniform random variables on other intervals of finite length.The derivation adds to the literature about methodologies for finding distributions …

Application Of Variational Principle To Form Reduced Fluid-Structure Interaction Models In Bifurcated Networks, Alexander S. Liberson, Yashar Seyed Vahedein, David A. Borkholder

Articles

Reduced fluid-structure interaction models have received a considerable attention in recent years being the key component of hemodynamic modeling. A variety of models applying to specific physiological components such as arterial, venous and cerebrospinal fluid (CSF) circulatory systems have been developed based on different approaches. The purpose of this paper is to apply the general approach based on Hamilton’s variational principle to create a model for a viscous Newtonian Fluid - Structure Interaction (FSI) in a compliant bifurcated network. This approach provides the background for a correct formulation of reduced FSI models with an account for arbitrary nonlinear visco-elastic properties …

Evaluation Of The Antimicrobial Activities Of Ultrasonicated Spinach Leaf Extracts Using Rapd Markers And Electron Microscopy, Ammar Badran Altemimi, Naoufal Lakhssassi, Amer Abughazaleh, David Lightfoot

Articles

Spinach (Spinacia oleracea L.) leaves represent an important dietary source of nutrients, antioxidants, and antimicrobials. As such, spinach leaves play an important role in health and have been used in the treatment of human diseases since ancient times. Here the aims were to optimize the extraction methods for recovering antimicrobial substances of spinach leaves, determine the minimum inhibitory concentrations (MICs) of the antimicrobial substances against Escherichia coli and Staphylococcus aureus and finally, evaluate the effects of spinach leaves’ antimicrobials on bacterial DNA using central composite face centered methods (CCFC). The effect of the extracts on both Gram positive and …

A Unified Cfd Based Approach To A Variety Of Condensation Processes In A Viscous Turbulent Wet Steam Flow, Alexander S. Liberson, Steven H. Hesler

Articles

A family of quasi linear mathematical models is presented and calculations made for viscous turbulent wet steam flow with a variety of condensation phenomena. These models can be applied to the analysis of equilibrium condensation, homogeneous (spontaneous) condensation, heterogeneous condensation on extraneous particles, and condensation of charged dispersed phase moving in an electrostatic field. The unified model is represented by coupled systems of gas dynamic equations for viscous turbulent two-phase flow, kinetic and electro-kinetic equations tracing out combined processes of size and charge growth, and electromagnetic field equations described an electric field with an account of self- induced in-part by …

Forfeitures And The Eighth Amendment: A Practical Approach To The Excessive Fines Clause As A Check On Government Seizures, David Pimentel

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No abstract provided.

Formulation, Characterisation And Stability Assessment Of A Food Derived 1 Tripeptide, Leucine-Lysine-Proline Loaded Chitosan Nanoparticles, Minna Khalid Danish, Giuliana Vozza, Hugh Byrne, Jesus Maria Frias, Sinead Ryan

Articles

The chicken or fish derived tripeptide, Leucine-Lysine-Proline (LKP), inhibits the Angiotensin Converting Enzyme and may be used as an alternative treatment for pre-hypertension. However, it has low permeation across the small intestine. The formulation of LKP into a nanoparticle (NP) has the potential to address this issue. LKP-loaded NPs were produced using an ionotropic gelation technique, using chitosan (CL113). Following optimisation of unloaded NPs, a mixture amount design was constructed using variable concentration of CL113 and tripolyphosphate at a fixed LKP concentration. Resultant particle sizes ranged from 120-271 nm, zeta potential values from 29-37 mV and polydispersity values from 0.3-0.6. …

Antifungal Potential Of Copper(Ii), Manganese(Ii) And Silver(I) 1,10-Phenanthroline Chelates Against Multidrug-Resistant Fungal Species Forming The Candida Haemulonii Complex: Impact On The Planktonic And Biofilm Lifestyles, Rafael M. Gandra, Pauraic Mc Carron, Mariana F. Fernandes, Lívia S. Ramos, Thaís P. Mello, Ana Carolina Aor, Marta H. Branquinha, Malachy Mccann, Michael Devereux, André L. S. Santos

Articles

Candida haemulonii, Candida haemulonii var. vulnera and Candida duobushaemulonii, which form the C. haemulonii complex, are emerging etiologic agents of fungal infections known to be resistant to the most commonly used antifungals. The well-established anti-Candida potential ofmetal complexes containing 1,10-phenanthroline (phen) ligands encouraged us to evaluate different copper(II), manganese(II), and silver(I) phen chelates for their ability to inhibit planktonic growth and biofilm of C. haemulonii species complex. Two novel coordination complexes, {[Cu(3,6,9-tdda)(phen)2].3H2O.EtOH}n and [Ag2(3,6,9-tdda)(phen)4].EtOH (3,6,9-tddaH2 = 3,6,9-trioxaundecanedioic acid), were synthesized in a similar fashion to the other, previously documented, sixteen copper(II), manganese(II), and silver(I) chelates employed herein. Three isolates of …

Solid-Phase Peptide Synthesis Of Analogues Of The N-Terminus A-Ring Fragment Of The Lantibiotic Nisin: Replacements For The Dehydroalanine (Dha) Residue At Position 5 And The First Incorporation Of A Thioamide Residue, Kim Manzor, Keith Ó Proinsias, Fintan Kelleher

Articles

A number of A-ring analogues of the lantibiotic nisin, containing replacements for the Dha at position 5, have been successfully prepared by solid-phase peptide synthesis. The Dha replacements include glycine, alanine, phenylalanine, serine and 1-aminocyclopropyl carboxylic acid (ACCa). The incorporation of a thioamide-isoleucine residue at position 4 is also described and is the first report of the preparation of a lantibiotic ring fragment containing a thioamide link.

Property Is Only Another Name For Monopoly, Eric A. Posner, E. Glen Weyl

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No abstract provided.

Ultra-Filtration Of Human Serum For Improved Quantitative Analysis Of Low Molecular Weight Biomarkers Using Atr-Ir Spectroscopy, Franck Bonnier, Luis Felipe Cs. Carvalho, Matthew 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, …

Delivering Design Fundamentals Using Relevant Learning Theories In The Delivery Of An Interior Design Project At Third Level, Tracey Dalton

Articles

This is a reflection on teaching practice, focussing on design process in a BA Honours in Design – Interior and Furniture, in Dublin Institute of Technology (DIT). An intrinsic case study approach (Stake 1995) was taken for this research, which focussed on the use of the learning theories in the delivery of an undergraduate interior design project brief. A third year commercial office design project has been used to assess teaching and learning styles. This article will show that, in terms of delivery, in a typical third level interior design project in DIT, the process incorporates all of the learning …

Industrial Grade 2d Molybdenum Disulphide (Mos2): An In-Vitro Exploration Of The Impact On Cellular Uptake, Cytotoxicity, And Inflammation, Caroline Moore, Hugh Byrne, Jonathan N. Coleman, Yuri Volkov, Jennifer Mcintyre

Articles

The recent surge in graphene research, since its liquid phase monolayer isolation and characterization in 2004, has led to advancements which are accelerating the exploration of alternative 2D materials such as molybdenum disulphide (MoS2), whose unique physico-chemical properties can be exploited in applications ranging from cutting edge electronic devices to nanomedicine. However, to assess any potential impact on human health and the environment, the need to understand the bio-interaction of MoS2 at a cellular and sub-cellular level is critical. Notably, it is important to assess such potential impacts of materials which are produced by large scale production techniques, rather than …

Extraoral Maxillofacial Prosthesis Implant Retention Systems: A Critical Review., Hugh Byrne, Marina L. Pimentel

Articles

Objectives: The purpose of this literature review is to provide information on the different available techniques for implant-supported prosthetic retention, which are bar-clip, o-ring or magnets. Through presenting the practitioner preferences reported in literature, although limited from strict comparison due to the heterogeneity of methodologies and studied individuals, this review aims to identify the choices for maxillofacial prosthesis implant retention systems, regarding patient comfort and good aesthetic outcome, as an aid to surgical and prosthetic planning for implant-supported extraoral maxillofacial prosthetics. With proper knowledge of each implant retention system, a practitioner can design a treatment plan which allows for a …

Conformational Studies Of Gram-Negative Bacterial Quorum Sensing 3-Oxo N-Acyl Homoserine Lactone Molecules, Darren Crowe, Alan Nicholson, Adrienne Fleming, Ed Carey, Goar Sanchez-Sanz, Fintan Kelleher

Articles

In their ¹H NMR spectra in CDCl₃ 3-oxo-N-acyl homoserine lactones (OHLs) show significant downfield chemical shifts of the amide N-H proton when compared to the parent N-acyl homoserine lactones (AHLs). NMR spectroscopic and DFT calculation studies have shown that this is most likely due to the presence of a stabilising intramolecular H-bond from the N-H to the 3-oxo group. The ¹H NMR spectra also show evidence for the enol tautomers and that the amount of enol present for a range of OHLs is 4.1-4.5% in CDCl₃ and 6.5-7.2% in CD₃CN. In …