Showing papers by "Dublin City University published in 2009"

Antibody-Based Sensors: Principles, Problems and Potential for Detection of Pathogens and Associated Toxins

Abstract: Antibody-based sensors permit the rapid and sensitive analysis of a range of pathogens and associated toxins. A critical assessment of the implementation of such formats is provided, with reference to their principles, problems and potential for 'on-site' analysis. Particular emphasis is placed on the detection of foodborne bacterial pathogens, such as Escherichia coli and Listeria monocytogenes, and additional examples relating to the monitoring of fungal pathogens, viruses, mycotoxins, marine toxins and parasites are also provided.

Detection of Ga suboxides and their impact on III-V passivation and Fermi-level pinning

Abstract: The passivation of interface states remains an important problem for III-V based semiconductor devices. The role of the most stable bound native oxides GaOx (0.5≤x≤1.5) is of particular interest. Using monochromatic x-ray photoelectron spectroscopy in conjunction with controlled GaAs(100) and InGaAs(100) surfaces, a stable suboxide (Ga2O) bond is detected at the interface but does not appear to be detrimental to device characteristics. In contrast, the removal of the Ga 3+ oxidation state (Ga2O3) is shown to result in the reduction of frequency dispersion in capacitors and greatly improved performance in III-V based devices.

Query dependent pseudo-relevance feedback based on wikipedia

Abstract: Pseudo-relevance feedback (PRF) via query-expansion has been proven to be e®ective in many information retrieval (IR) tasks. In most existing work, the top-ranked documents from an initial search are assumed to be relevant and used for PRF. One problem with this approach is that one or more of the top retrieved documents may be non-relevant, which can introduce noise into the feedback process. Besides, existing methods generally do not take into account the significantly different types of queries that are often entered into an IR system. Intuitively, Wikipedia can be seen as a large, manually edited document collection which could be exploited to improve document retrieval effectiveness within PRF. It is not obvious how we might best utilize information from Wikipedia in PRF, and to date, the potential of Wikipedia for this task has been largely unexplored. In our work, we present a systematic exploration of the utilization of Wikipedia in PRF for query dependent expansion. Specifically, we classify TREC topics into three categories based on Wikipedia: 1) entity queries, 2) ambiguous queries, and 3) broader queries. We propose and study the effectiveness of three methods for expansion term selection, each modeling the Wikipedia based pseudo-relevance information from a different perspective. We incorporate the expansion terms into the original query and use language modeling IR to evaluate these methods. Experiments on four TREC test collections, including the large web collection GOV2, show that retrieval performance of each type of query can be improved. In addition, we demonstrate that the proposed method out-performs the baseline relevance model in terms of precision and robustness.

Bio-sensing textile based patch with integrated optical detection system for sweat monitoring

Abstract: Sensors, which can be integrated into clothing and used to measure biochemical changes in body fluids, such as sweat, constitute a major advancement in the area of wearable sensors. Initial applications for such technology exist in personal health and sports performance monitoring. However, sample collection is a complicated matter as analysis must be done in real-time in order to obtain a useful examination of its composition. This work outlines the development of a textile-based fluid handling platform which uses a passive pump to gather sweat and move it through a pre-defined channel for analysis. The system is tested both in vitro and in vivo. In addition, a pH sensor, which depends on the use of a pH sensitive dye and paired emitter-detector LEDs to measure colour changes, has been developed. In vitro and on-body trials have shown that the sensor has the potential to record real-time variations in sweat during exercise.

Activation of TRPV1 mediates calcitonin gene-related peptide release, which excites trigeminal sensory neurons and is attenuated by a retargeted botulinum toxin with anti-nociceptive potential.

Abstract: Excessive release of inflammatory/pain mediators from peripheral sensory afferents renders nerve endings hyper-responsive, causing central sensitization and chronic pain. Herein, the basal release of proinflammatory calcitonin gene-related peptide (CGRP) was shown to increase the excitability of trigeminal sensory neurons in brainstem slices via CGRP1 receptors because the effect was negated by an antagonist, CGRP8–37. This excitatory action could be prevented by cleaving synaptosomal-associated protein of Mr 25,000 (SNAP-25) with botulinum neurotoxin (BoNT) type A, a potent inhibitor of exocytosis. Strikingly, BoNT/A proved unable to abolish the CGRP1 receptor-mediated effect of capsaicin, a nociceptive TRPV1 stimulant, or its elevation of CGRP release from trigeminal ganglionic neurons (TGNs) in culture. Although the latter was also not susceptible to BoNT/E, apparently attributable to a paucity of its acceptors (glycosylated synaptic vesicle protein 2 A/B), this was overcome by using a recombinant chimera (EA) of BoNT/A and BoNT/E. It bound effectively to the C isoform of SV2 abundantly expressed in TGNs and cleaved SNAP-25, indicating that its /A binding domain (HC) mediated uptake of the active /E protease. The efficacy of /EA is attributable to removal of 26 C-terminal residues from SNAP-25, precluding formation of SDS-resistant SNARE complexes. In contrast, exocytosis could be evoked after deleting nine of the SNAP-25 residues with /A but only on prolonged elevation of [Ca2+]i with capsaicin. This successful targeting of /EA to nociceptive neurons and inhibition of CGRP release in vitro and in situ highlight its potential as a new therapy for sensory dysmodulation and chronic pain.

High-level feature detection from video in TRECVid: a 5-year retrospective of achievements

Abstract: Successful and effective content-based access to digital video requires fast, accurate and scalable methods to determine the video content automatically. A variety of contemporary approaches to this rely on text taken from speech within the video, or on matching one video frame against others using low-level characteristics like colour, texture or shapes, or on determining and matching objects appearing within the video. Possibly the most important technique, however, is one that determines the presence or absence of a high-level or semantic feature, within a video clip or shot. By utilizing dozens, hundreds or even thousands of such semantic features we can support many kinds of content-based video navigation. Critically, however, this depends on being able to determine whether each feature is or is not present in a video clip. The last 5 years have seen much progress in the development of techniques to determine the presence of semantic features within video. This progress can be tracked in the annual TRECVid benchmarking activity where dozens of research groups measure the effectiveness of their techniques on common data and using an open, metrics-based approach. In this chapter we summarize the work done on the TRECVid high-level feature task, showing the progress made year-on-year. This provides a fairly comprehensive statement on where the state-of-the-art is regarding this important task, not just for one research group or for one approach, but across the spectrum. We then use this past and on-going work as a basis for highlighting the trends that are emerging in this area, and the questions which remain to be addressed before we can achieve large-scale, fast and reliable high-level feature detection on video.

High performance work systems in Ireland: human resource and organizational outcomes

Abstract: From the perspective of the resource based view (RBV), although traditional sources of competitive advantage such as natural resources, technology, economies of scales, and so forth, create value, these resources are increasingly easy to imitate. As such, human capital and human resource management may be an especially important source of sustainable competitive advantage. Over the past few years, there has been growing research interest in the competitive advantage associated with high performance work systems (HPWS), a set of management policies and practices thought to endow employees with greater levels of skill, information, motivation and discretion. In this study, we describe a study examining the relative effectiveness of HPWS in the Irish context. Results suggest that greater use of high performance work systems is associated with positive human resource and organizational outcomes. Specifically, firms utilizing higher levels of HPWS tend to have lower rates of employee absenteeism and voluntary ...

Host Students' Perspectives of Intercultural Contact in an Irish University

Abstract: Given the increasing numbers of international students in Ireland and the lack of attention afforded to host culture students in existing research on intercultural relations in higher education, a grounded theory study was conducted in an Irish university exploring host (Irish) students' perspectives on intercultural contact. The study focused on students' construction of cultural difference within the educational environment, the factors influencing intercultural contact, and students' experiences of such contact. The findings suggest that although nationality and age are used to differentiate students, the concept of “maturity”—underpinned by values and behaviors relating to academic motivations, responsibilities, and authority—is central to students' construction of cultural difference on campus.Diverse factors identified as impacting upon students' intercultural acquaintance prospects and relational development are presented and discussed. The findings highlight the complexity of promoting meaningful ...

Combining Social Network Analysis and Sentiment Analysis to Explore the Potential for Online Radicalisation

Abstract: The increased online presence of jihadists has raised the possibility of individuals being radicalised via the Internet. To date, the study of violent radicalisation has focused on dedicated jihadist websites and forums. This may not be the ideal starting point for such research, as participants in these venues may be described as "already made-up minds". Crawling a global social networking platform, such as YouTube, on the other hand, has the potential to unearth content and interaction aimed at radicalisation of those with little or no apparent prior interest in violent jihadism. This research explores whether such an approach is indeed fruitful. We collected a large dataset from a group within YouTube that we identified as potentially having a radicalising agenda. We analysed this data using social network analysis and sentiment analysis tools, examining the topics discussed and what the sentiment polarity (positive or negative) is towards these topics. In particular, we focus on gender differences in this group of users, suggesting most extreme and less tolerant views among female users.

Evolution of User-generated Translation: Fansubs, Translation Hacking and Crowdsourcing

Abstract: Most conspicuous initially with Japanese anime fansubs, fan-based translation has been developing since the 1980s. In the advent of widespread availability of Web 2.0 platforms, fan translation has become a global phenomenon despite its dubious legal status. Extending the emerging interest in fansubs and scanlation in translation studies to the little discussed translation hacking by video game fans, this article brings readers‘ attention to participatory culture manifest in user-generated content in the field of translation and localisation. The article describes the evolution from unsolicited fan translation to solicited community translation now called crowdsourcing and considers them in the framework of user-generated translation (UGT). The article provides interdisciplinary perspectives, drawing on insights from media and game studies to address UGT which could profoundly impact the profession of translation and localisation as new technological environments unleash the technical competence, genre-knowledge and unparalleled devotion of the otherwise untrained Internet crowd as translators.This article is made available under a CC BY-NC 4.0 license.

Physically crosslinked composite hydrogels of PVA with natural macromolecules: structure, mechanical properties, and endothelial cell compatibility.

Abstract: Polyvinyl alcohol (PVA) hydrogels have been considered potentially suitable for applications as engineered blood vessels because of their structure and mechanical properties. However, PVA's hydrophilicity hinders its capacity to act as a substrate for cell attachment. As a remedy, PVA was blended with chitosan, gelatin, or starch, and hydrogels were formed by subjecting the solutions to freeze-thaw cycles followed by coagulation bath immersion. The structure-property relationships for these hydrogels were examined by measurement of their swelling, rehydration, degradation, and mechanical properties. For the case of pure PVA hydrogels, the equilibrium swelling ratio was used to predict the effect of freeze thaw cycles and coagulation bath on average molecular weights between crosslinks and on mesh size. For all hydrogels, trends for the reswelling ratio, which is indicative of the crosslinked polymer fraction, were consistent with relative tensile properties. The coagulation bath treatment increased the degradation resistance of the hydrogels significantly. The suitability of each hydrogel for cell attachment and proliferation was examined by protein adsorption and bovine vascular endothelial cell culture experiments. Protein adsorption and cell proliferation was highest on the PVA/gelatin hydrogels. This study demonstrates that the potential of PVA hydrogels for artificial blood vessel applications can be improved by the addition of natural polymers, and that freeze-thawing and coagulation bath treatment can be utilized for fine adjustment of the physical characteristics.

Blind and Anonymous Identity-Based Encryption and Authorised Private Searches on Public Key Encrypted Data

Abstract: Searchable encryption schemes provide an important mechanism to cryptographically protect data while keeping it available to be searched and accessed. In a common approach for their construction, the encrypting entity chooses one or several keywords that describe the content of each encrypted record of data. To perform a search, a user obtains a trapdoor for a keyword of her interest and uses this trapdoor to find all the data described by this keyword. We present a searchable encryption scheme that allows users to privately search by keywords on encrypted data in a public key setting and decrypt the search results. To this end, we define and implement two primitives: public key encryption with oblivious keyword search (PEOKS) and committed blind anonymous identity-based encryption (IBE). PEOKS is an extension of public key encryption with keyword search (PEKS) in which users can obtain trapdoors from the secret key holder without revealing the keywords. Furthermore, we define committed blind trapdoor extraction, which facilitates the definition of authorisation policies to describe which trapdoor a particular user can request. We construct a PEOKS scheme by using our other primitive, which we believe to be the first blind and anonymous IBE scheme. We apply our PEOKS scheme to build a public key encrypted database that permits authorised private searches, i.e., neither the keywords nor the search results are revealed.

On the Final Exponentiation for Calculating Pairings on Ordinary Elliptic Curves

Abstract: When performing a Tate pairing (or a derivative thereof) on an ordinary pairing-friendly elliptic curve, the computation can be looked at as having two stages, the Miller loop and the so-called final exponentiation. As a result of good progress being made to reduce the Miller loop component of the algorithm (particularly with the discovery of "truncated loop" pairings like the R-ate pairing [18]), the final exponentiation has become a more significant component of the overall calculation. Here we exploit the structure of pairing-friendly elliptic curves to reduce to a minimum the computation required for the final exponentiation.

Carbon Trading: A Critical Conversation on Climate Change, Privatisation and Power

Abstract: Carbon Trading: A Critical Conversation on Climate Change, Privatisation and Powerby Larry Lohmann; Uddevalla: Dag Hammersjold Foundation, The Durban Group for Climate Justice and The Corner House,...

A Race to the Bottom? Trade Unions, EU Enlargement and the Free Movement of Labour

Abstract: When eight countries from Central and Eastern Europe joined the EU in 2004, unions in some countries argued that significant wage differentials between the old and the new member states necessitate

Human resource management : A critical approach

Abstract: 1. Introduction (David G. Collings and Geoffrey Wood) Section 1: The Context of HRM 2. HRM in Changing Organizational Contexts (Phil Johnson) 3. Strategic HRM: A Critical Review (Jaap Paauwe and Corine Boon) 4. HRM and Organizational Performance (Stephen Wood) 5. HRM: An Ethical Perspective (Mick Fryer) 6. Organizational Outsourcing and the Implications for HRM (Richard Haines) 7. The Socio-Cultural Aspects of Knowledge Management and the Links to HRM: A Critical Perspective (Donald Hislop) 8. HRM in Small and Medium-Sized Enterprises (SMEs) (Tony Dundon and Adrian Wilkinson) Section 2: The Practice of HRM 9. Recruitment and Selection (Rosalind Searle) 10. HR Planning: Institutions, Strategy, Tools and Techniques (Zsuzsa Kispal-Vitai and Geoffrey Wood) 11. Performance Management (Anthony McDonnell and Patrick Gunnigle) 12. Reward Management (Suzanne Richbell and Geoffrey Wood) 13. Human Resource Development (Irena Grugulis) 14. Industrial Relations and Human Resource Management (Gilton Klerck) Section 3: The International Context of HRM 15. Human Resource Management in Emerging Markets (Frank M. Horwitz and Kamel Mellahi) 16. Comparative HRM: The Debates and the Evidence (Chris Brewster and Wolfgang Mayrhofer) 17. International Human Resource Management (David G. Collings, Hugh Scullion and Deirdre Curran)

Cultural translation: An introduction to the problem, and Responses

Abstract: Etymologically, translation evokes an act of moving or carrying across from one place or position to another, or of changing from one state of things to another. This does not apply only to the words of different languages, but also to human beings and their most important properties. They too can be moved across all sorts of differences and borders and so translated from one place to another, for instance from one cultural and political condition to another. Thus, one can culturally translate people – for a political purpose and with existential consequences. No discussion of the concept of cultural translation can easily dispense with an analysis of the very concrete devices of such translation if it strives to maintain contact with the political and existential issues at stake in the debate on cultural translation. The political meaning of cultural translation is not a quality external to the concept and capable of being discussed in a haphazard way. Precisely by becoming cultural, translation opens up...

Determination of the influence of stent strut thickness using the finite element method: implications for vascular injury and in-stent restenosis

Abstract: Many clinical studies, including the ISAR-STEREO trial, have identified stent strut thickness as an independent predictor of in-stent restenosis where thinner struts result in lower restenosis than thicker struts. The aim of this study was to more conclusively identify the mechanical stimulus for in-stent restenosis using results from such clinical trials as the ISAR-STEREO trial. The mechanical environment in arteries stented with thin and thicker strut stents was investigated using numerical modelling techniques. Finite element models of the stents used in the ISAR-STEREO clinical trial were developed and the stents were deployed in idealised stenosed vessel geometries in order to compare the mechanical environment of the vessel for each stent. The stresses induced within the stented vessels by these stents were compared to determine the level of vascular injury caused to the artery by the stents with different strut thickness. The study found that when both stents were expanded to achieve the same initial maximum stent diameter that the thinner strut stent recoiled to a greater extent resulting in lower luminal gain but also lower stresses in the vessel wall, which is hypothesised to be responsible for the lower restenosis outcome. This study supports the hypothesis that arteries develop restenosis in response to injury, where high vessel stresses are a good measure of that injury. This study points to a critical stress level in arteries, above which an aggressive healing response leads to in-stent restenosis in stented vessels. Stents can be designed to reduce stresses in this range in arteries using preclinical tools such as numerical modelling.