Institutes and Centres

Principles of Electrospray Ionization

2013-04-15T11:48:41Z

Principles of Electrospray Ionization Wilm, M Electrospray ionization is today the most widely used ionization technique in chemical and bio-chemical analysis. Interfaced with a mass spectrometer it allows to investigate the molecular composition of liquid samples. With electrospray a large variety of chemical substances can be ionized. There is no limitation in mass which enables even the investigation of large non-covalent protein complexes. Its high ionization efficiency profoundly changed bio-molecular sciences because proteins can be identified and quantified on trace amounts in a high throughput fashion. This review article focusses mainly on the exploration of the underlying ionization mechanism. Some ionization characteristics are discussed which are related to this mechanism. Typical spectra of peptides, proteins and non-covalent complexes are shown and the quantitative character of spectra is highlighted. Finally the possibilities and limitations in measuring the association constant of bivalent non-covalent complexes are described.

Quantitative proteomics in biological research

2013-04-15T11:43:10Z

Quantitative proteomics in biological research Wilm, Matthias Proteomics has enabled the direct investigation of biological material, at first through the analysis of individual proteins, then of lysates from cell cultures, and finally of extracts from tissues and biopsies from entire organisms. Its latest manifestation - quantitative proteomics - allows deeper insight into biological systems. This article reviews the different methods used to extract quantitative information from mass spectra. It follows the technical developments aimed toward global proteomics, the attempt to characterize every expressed protein in a cell by at least one peptide. When applications of the technology are discussed, the focus is placed on yeast biology. In particular, differential quantitative proteomics, the comparison between an experiment and its control, is very discriminating for proteins involved in the process being studied. When trying to understand biological processes on a molecular level, differential quantitative proteomics tends to give a clearer picture than global transcription analyses. As a result, MS has become an even more indispensable tool for biochemically motivated biological research.

Frequency modulation atomic force microscopy in ambient environments utilizing robust feedback tuning

2013-04-08T15:49:43Z

Frequency modulation atomic force microscopy in ambient environments utilizing robust feedback tuning Kilpatrick, J. I.; Gannepalli, A.; Cleveland, J. P.; Jarvis, Suzi Frequency modulation atomic force microscopy (FM-AFM) is rapidly evolving as the technique of choice in the pursuit of high resolution imaging of biological samples in ambient environments. The enhanced stability afforded by this dynamic AFM mode combined with quantitative analysis enables the study of complex biological systems, at the nanoscale, in their native physiological environment. The operational bandwidth and accuracy of constant amplitude FM-AFM in low Q environments is heavily dependent on the cantilever dynamics and the performance of the demodulation and feedback loops employed to oscillate the cantilever at its resonant frequency with a constant amplitude. Often researchers use ad hoc feedback gains or instrument default values that can result in an inability to quantify experimental data. Poor choice of gains or exceeding the operational bandwidth can result in imaging artifacts and damage to the tip and/or sample. To alleviate this situation we present here a methodology to determine feedback gains for the amplitude and frequency loops that are specific to the cantilever and its environment, which can serve as a reasonable "first guess", thus making quantitative FM-AFM in low Q environments more accessible to the nonexpert. This technique is successfully demonstrated for the low Q systems of air (Q∼40) and water (Q∼1). In addition, we present FM-AFM images of MC3T3-E1 preosteoblast cells acquired using the gains calculated by this methodology demonstrating the effectiveness of this technique.

Electrochemical characterization of NiO electrodes deposited via a scalable powder microblasting technique

2013-04-08T14:24:06Z

Electrochemical characterization of NiO electrodes deposited via a scalable powder microblasting technique Awais, Muhammad; Dini, Danilo; MacElroy, J. M. Don; Halpin, Yvonne; Vos, Johannes G.; Dowling, Denis P. In this contribution a novel powder coating processing technique (microblasting) for the fabrication of nickel oxide (NiOx) coatings is reported. ~1.2 μm thick NiOx coatings are deposited at 20 mm2 s−1 by the bombardment of the NiOx powder onto a Ni sheet using an air jet at a speed of more than 180 m s−1. Microblast deposited NiOx coatings can be prepared at a high processing rate, do not need further thermal treatment. Therefore, this scalable method is time and energy efficient. The mechano-chemical bonding between the powder particles and substrate results in the formation of strongly adherent NiOx coatings. Microstructural analyses were carried out using SEM, the chemical composition and coatings orientation were determined by XPS and XRD, respectively. The electroactivity of the microblast deposited NiOx coatings was compared with that of NiOx coatings obtained by sintering NiOx nanoparticles previously sprayed onto Ni sheets. In the absence of a redox mediator in the electrolyte, the reduction current of microblast deposited NiOx coatings, when analyzed in anhydrous environment, was two times larger than that produced by higher porosity NiOx nanoparticles coatings of the same thickness obtained through spray coating followed by sintering. Under analogous experimental conditions thin layers of NiOx obtained by using the sol–gel method, ultrasonic spray- and electro-deposition show generally lower current density with respect to microblast samples of the same thickness. The electrochemical reduction of NiOx coatings is controlled by the bulk characteristics of the oxide and the relatively ordered structure of microblast NiOx coatings with respect to sintered NiOx nanoparticles here considered, is expected to increase the electron mobility and ionic charge diffusion lengths in the microblast samples. Finally, the increased level of adhesion of the microblast film on the metallic substrate affords a good electrical contact at the metal/metal oxide interface, and constitutes another reason in support of the choice of microblast as low-cost and scalable deposition method for oxide layers to be employed in electrochemical applications.

Fiscal politics in time: pathways to fiscal consolidation, 1980-2012

2013-04-08T14:09:46Z

Fiscal politics in time: pathways to fiscal consolidation, 1980-2012 Dellepiane, Sebastian; Hardiman, Niamh The comparative study of debt and fiscal consolidation has acquired a new focus in the wake of the global financial crisis. This leads us to re-evaluate the literature on fiscal consolidation that flourished during the 1980s and 1990s. The conventional approach segments episodes of fiscal change into discrete observations. We argue that this misses the dynamic features of government strategy, especially in the choices made between expenditure-based and revenue-based fiscal consolidation strategies. We propose a focus on pathways rather than episodes of adjustment, to recapture what Pierson terms 'politics in time'. A case-study approach facilitates analysis of complex causality that includes the structures of interest intermediation, the role of ideas in shaping the set of feasible policy choices, and the situation of national economies in the international political economy. We support our argument with qualitative data based on two case studies, Ireland and Greece, and with additional paired comparisons of Ireland with Britain, and Greece with Spain.

Parameter sensitivity of a watershed-scale flood forecasting model as a function of modelling time-step

2013-04-05T10:45:01Z

Parameter sensitivity of a watershed-scale flood forecasting model as a function of modelling time-step O'Loughlin, Fiachra; Bruen, Michael; Wagener, Thorsten Despite significant developments, the simple, lumped, conceptual, rainfall-runoff model is still widely used for flood forecasting. What may not be appreciated is that, while such models can often be calibrated to give reasonable forecasts of flood flows, both parameter values and the fluxes of water through individual model components change significantly with the time step used. This means that such models should be used with caution for studies which require “internal” information, such as hydrograph separation or water quality studies that depend on knowing the fluxes through individual flow routes through the model and in studies which try to relate parameter values to physical features of the catchment. To demonstrate this time-scale limitation, a parameter sensitivity analysis was performed on a typical lumped conceptual model (SMARG) applied to a small rural catchment on the Irish East Coast for a number of different time-steps, flow regimes and evaluation metrics. A global sensitivity analysis method (GUI-HDMR, is applied to calculate sensitivity indices which varied greatly with time-step and evaluation metric used. The sensitivity of parameters also differed for different flow regimes. Care should be taken in using internal information and calibrated parameter in conceptual models because of the strong dependence on time-step.

The impact of a catastrophic storm event on benthic macroinvertebrate communities in upland headwater streams and potential implications for ecological diversity and assessment of ecological status

2013-04-03T11:35:14Z

The impact of a catastrophic storm event on benthic macroinvertebrate communities in upland headwater streams and potential implications for ecological diversity and assessment of ecological status Feeley, Hugh B.; Davis, Stephen; Bruen, Michael; Blacklocke, Sean; Kelly-Quinn, Mary Upland headwater streams are dynamic systems, responding rapidly to changes in climatic conditions. This study examined the effects of a catastrophic rainfall event, that occured on 24 October 2011 on the east coast of Ireland, on the macroinvertebrate community composition and structure of four headwater streams in the river Liffey catchment located in the Wicklow Mountains. The ecological status before and after the storm were also evaluated. The water level and pH of each stream were recorded using continuous monitoring equipment, while rainfall data for the study period were sourced from a local weather station. Benthic macroinvertebrates were investigated before and after the storm event using Surber sampling. Results showed rapid and large increases in water level and significant declines in stream pH in response to intensive rainfall during the storm. The high water levels also caused major physical damage and abrasion in all four streams, that significantly altered instream habitats. The storm event induced significant losses to the richness and/or density of most taxonomic groups, with the exception of the Plecoptera. Furthermore, the overall community composition and structure changed significantly, most likely as a result of physical disturbance, given the relative persistence of acid-sensitive taxa and the relatively short period of harsh acidic conditions (<5 pH). Interestingly however, the ecological status of each of the four study sites, tested using Stream Risk Score (SSRS), Biological Monitoring Working Party (BMWP) and the Average Score Per Taxon (ASPT) indices, was unaltered by the loss in richness and densities. This was likely a result of the maintenance of plecopteran richness and the absence of organic pollution, thus highlighting the need to develop appropriate indices to assess the ecological status of streams and rivers affected by physical disturbance caused by large storm events. Ultimately, catastrophic storm events in upland headwater streams have potentially major implications for the maintenance of regional macroinvertebrate diversity within affected regions.

Dye sensitised solar cells with nickel oxide photocathodes prepared via scalable microwave sintering

2013-03-20T12:40:08Z

Dye sensitised solar cells with nickel oxide photocathodes prepared via scalable microwave sintering Gibson, Elizabeth A.; Awais, Muhammad; Dini, Danilo; Dowling, Denis P.; Pryce, Mary T.; Vos, Johannes G.; Boschloo, Gerrit; Hagfeldt, Anders Photoactive NiO electrodes for cathodic dye-sensitised solar cells (p-DSCs) have been prepared with thicknesses ranging between 0.4 and 3.0 mm by spray-depositing pre-formed NiO nanoparticles on fluorine-doped tin oxide (FTO) coated glass substrates. The larger thicknesses were obtained in sequential sintering steps using a conventional furnace (CS) and a newly developed rapid discharge sintering (RDS) method. The latter procedure is employed for the first time for the preparation of p-DSCs. In particular, RDS represents a scalable procedure that is based on microwave-assisted plasma formation that allows the production in series of mesoporous NiO electrodes with large surface areas for p-type cell photocathodes. RDS possesses the unique feature of transmitting heat from the bulk of the system towards its outer interfaces with controlled confinement of the heating zone. The use of RDS results in a drastic reduction of processing times with respect to other deposition methods that involve heating/calcination steps with associated reduced costs in terms of energy. P1-dye sensitized NiO electrodes obtained via the RDS procedure have been tested in DSC devices and their performances have been analysed and compared with those of cathodic DSCs derived from CS-deposited samples. The largest conversion eﬃciencies (0.12%) and incident photon-to-current conversion eﬃciencies, IPCEs (50%), were obtained with sintered NiO electrodes having thicknesses of B1.5–2.0 mm. In all the devices, the photogenerated holes in NiO live significantly longer (th B 1 s) than have previously been reported for P1-sensitized NiO photocathodes. In addition, P1-sensitised sintered electrodes give rise to relatively high photovoltages (up to 135 mV) when the triiodide–iodide redox couple is used.

Spray deposited NiOx films on ITO substrates as photoactive electrodes for p-type dye-sensitized solar cells

2013-03-20T12:22:03Z

Spray deposited NiOx films on ITO substrates as photoactive electrodes for p-type dye-sensitized solar cells Awais, Muhammad; Dowling, Denis P.; Rahman, Mahfujur; Vos, Johannes G.; Decker, Franco; Dini, Danilo Spray deposition followed by sintering of nickel oxide (NiO x ) nanoparticles (average diameter: 40 nm) has been chosen as method of deposition of mesoporous NiO x coatings onto indium tin oxide (ITO) substrates. This procedure allows the scalable preparation of NiO x samples with large surface area (~103 times the geometrical area) and its potential for applications such as electrocatalysis or electrochemical solar energy conversion, which require high electroactivity in confined systems. The potential of these NiO x films as semiconducting cathodes for dye-sensitized solar cell (DSC) purposes has been evaluated for 0.3–3-μm-thick films of NiO x sensitized with erythrosine B (ERY). The electrochemical processes involving the NiO x coatings in the pristine and sensitized states were examined and indicated surface confinement as demonstrated by the linear dependence of the current densities with the scan rate of the cyclic voltammetry. Cathodic polarization of NiO x on ITO can also lead to the irreversible reduction of the underlying ITO substrate because of the mesoporous nature of the sintered NiO x film that allows the shunting of ITO to the electrolyte. ITO-based reduction processes alter irreversibly the properties of charge transfer through the ITO/NiOx interface and limit the range of potential to NiO x coatings sintered for DSC purposes.

Comprehensive analysis of step-feeding strategy to enhance biological nitrogen removal in alum sludge-based tidal flow constructed wetlands

2013-01-14T14:44:25Z

Comprehensive analysis of step-feeding strategy to enhance biological nitrogen removal in alum sludge-based tidal flow constructed wetlands Hu, Y.S.; Zhao, Y.Q.; Zhao, X.H.; Kumar, J.L.G. Step-feeding strategies have been extensively studied and comprehensively analyzed in this study for a four-stage alum sludge-based tidal flow constructed wetlands (AlS-TFCWs) system. Enhanced total nitrogen removal of 83% is achieved under high nitrogen loading rate of 19.1 g N/m2 d. The key issues towards the success of a significant nitrogen removal in step-feeding TFCWs are the bed resting time (which provides better aeration for nitrification) and up flow stage/delayed input of side stream(s) (which ensure favorable environment for better denitrification). Simultaneous nitrification and denitrification (SND) was found effective in the 1st stage of the system and SND via nitrite is the main nitrogen conversion mechanism. The optimal influent distribution fraction for step-feeding purpose can be estimated from a theoretical basis, which is a function of the influent BCOD/TKN ratio. Therefore the influent distribution fraction should be adjusted according to the variety of influent characteristics, rather than a fixed value.

Fuzzy synthetic evaluation of Weihe water quality

2013-01-14T14:37:21Z

Fuzzy synthetic evaluation of Weihe water quality Geng, Yani; Zhang, Jun; Zhou, Qi; Xu, Chundi; Zhao, Y.Q. Based on the fuzzy logic principle, a modified Fuzzy Synthetic Evaluation (FSE) is proposed to assess water quality status of Weihe River (Baoji, China). The potential application of the FSE has been tested in a case study. Twelve sampling locations of Weihe River and its tributaries in Baoji area were selected and seven water quality parameters of BOD5, COD, fluoride, ammonia, total phosphorus (TP), total nitrogen (TN) and permanganate index, were monitored from 2008 to 2009. The findings clearly indicated that the methodology adopted in this study was reasonably close to the official reports published by the local Environmental Protection Agency (EPA) on the pollution problems in the study area. The water quality of Weihe River in Baoji area showed the Class II and III according to the Chinese classification standard. More importantly, this provides a good showcase of the modified FSE in river water quality evaluation.

Expression of genes for bone morphogenetic proteins BMP-2, BMP-4 and BMP-6 in various parts of the human skeleton

2013-04-05T10:59:22Z

Expression of genes for bone morphogenetic proteins BMP-2, BMP-4 and BMP-6 in various parts of the human skeleton Kochanowska, Iwona; Chaberek, Slawomir; Wojtowicz, Andrzej; Marczynski, Bartosz; Włodarski, Krzysztof; Dytko, Malgorzata; Ostrowski, Kazimierz BACKGROUND: Differences in duration of bone healing in various parts of the human skeleton are common experience for orthopaedic surgeons. The reason for these differences is not obvious and not clear.METHODS: In this paper we decided to measure by the use of real-time RT-PCR technique the level of expression of genes for some isoforms of bone morphogenetic proteins (BMPs), whose role is proven in bone formation, bone induction and bone turnover. Seven bone samples recovered from various parts of skeletons from six cadavers of young healthy men who died in traffic accidents were collected. Activity of genes for BMP-2, -4 and -6 was measured by the use of fluorescent SYBR Green I.RESULTS: It was found that expression of m-RNA for BMP-2 and BMP-4 is higher in trabecular bone in epiphyses of long bones, cranial flat bones and corpus mandibulae then in the compact bone of diaphyses of long bones. In all samples examined the expression of m-RNA for BMP-4 was higher than for BMP-2.CONCLUSION: It was shown that m-RNA for BMP-6 is not expressed in the collected samples at all. It is postulated that differences in the level of activation of genes for BMPs is one of the important factors which determine the differences in duration of bone healing of various parts of the human skeleton.

Dementia in SPG4 hereditary spastic paraplegia : Clinical, genetic, and neuropathologic evidence

2013-04-05T11:00:00Z

Dementia in SPG4 hereditary spastic paraplegia : Clinical, genetic, and neuropathologic evidence Murphy, S.; Gorman, B.; Beetz, C.; Byrne, P.; Dytko, Malgorzata; McMonagle, P.; Kinsella, K.; Hutchinson, M. Background: Cognitive impairment and dementia has been reported in autosomal dominant hereditary spastic paraparesis (HSP) linked to the SPG4 locus. There has only been one postmortem examination described; not all accept that progressive cognitive decline is a feature of this disorder.Objective: A family with SPG4-HSP known to have a deletion of exon 17 in the spastin gene (SPG4delEx17) was cognitively assessed over a 7-year period. The index family member died and a postmortem examination was performed.Methods: Thirteen family members older than 40 years were clinically and cognitively assessed using the Cambridge Cognitive Assessment over a 7-year period. The presence of SPG4delEx17 was assessed; a neuropathologic examination of the brain of the index family member was performed.Results: Cognitive decline occurred in 6 of the 13 family members and in all 4 older than 60 years. Two genetic deletions were identified: SPG4delEx17 in 12 of the 13 family members and a deletion of SPG6 (SPG6del) in 5. Eight individuals had the SPG4delEx17 deletion only; 4 had evidence of progressive cognitive impairment. Four family members had both SPG4delEx17 and SPG6del; 2 of these had cognitive impairment. One family member with the SPG6del alone had neither HSP nor cognitive impairment. The index case with both deletions died with dementia; the brain showed widespread ubiquitin positivity within the neocortex and white matter.Conclusion: Cognitive decline and dementia is a feature of SPG4-HSP due to a deletion of exon 17 of the spastin gene. Neurology (R) 2009; 73: 378-384

Oil refinery wastewater treatment using physicochemical, Fenton and Photo-Fenton oxidation processes

2013-01-07T16:13:43Z

Oil refinery wastewater treatment using physicochemical, Fenton and Photo-Fenton oxidation processes Tony, Maha A.; Purcell, Patrick J.; Zhao, Y.Q. The objective of this study was to investigate the application of advanced oxidation processes (AOPs) to the treatment of wastewaters contaminated with hydrocarbon oil. Three different oil-contaminated wastewaters were examined and compared: (i) a ‘real’ hydrocarbon wastewater collected from an oil refinery (Conoco-Phillips Whitegate refinery, County Cork, Ireland); (ii) a ‘real’ hydrocarbon wastewater collected from a car-wash facility located at a petroleum filling station; and (iii) a ‘synthetic’ hydrocarbon wastewater generated by emulsifying diesel oil and water. The AOPs investigated were Fe2+/H2O2 (Fenton's reagent), Fe2+/H2O2/UV (Photo-Fenton's reagent) which may be used as an alternative to, or in conjunction with, conventional treatment techniques. Laboratory-scale batch and continuous-flow experiments were undertaken. The photo-Fenton parametric concentrations to maximize COD removal were optimized: pH = 3, H2O2 = 400 mg/L, and Fe2+ = 40 mg/L. In the case of the oil-refinery wastewater, photo-Fenton treatment achieved approximately 50% COD removal and, when preceded by physicochemical treatment, the percentage removal increased to approximately 75%.

High rate nitrogen removal in an alum sludge-based intermittent aeration constructed wetland

2013-03-16T04:00:15Z

High rate nitrogen removal in an alum sludge-based intermittent aeration constructed wetland Hu, Y.S.; Zhao, Y.Q.; Zhao, X.H.; Kumar, J.L.G. A new development on treatment wetland technology for the purpose of achieving high rate nitrogen removal from high strength wastewater has been made in this study. The laboratory scale alum sludge-based intermittent aeration constructed wetland (AlS-IACW) was integrated with predenitrification, intermittent aeration, and step-feeding strategies. Results obtained from 280 days of operation have demonstrated extraordinary nitrogen removal performance with mean total nitrogen (TN) removal efficiency of 90% under high N loading rate (NLR) of 46.7 g N m–2 d–1. This performance was a substantial improvement compared to the reported TN removal performance in literature. Most significantly, partial nitrification and simultaneous nitrification denitrification (SND) via nitrite was found to be the main nitrogen conversion pathways in the AlS-IACW system under high dissolved oxygen concentrations (3–6 mg L–1) without specific control. SND under high dissolved oxygen (DO) brings high nitrogen conversion rates. Partial nitrification and SND via nitrite can significantly reduce the demand for organic carbon compared with full nitrification and denitrification via nitrate (up to 40%). Overall, these mechanisms allow the system to maintaining efficient and high rate TN removal even under carbon limiting conditions.

Transformation of beneficially reused aluminium sludge to potential P and Al resource after employing as P-trapping material for wastewater treatment in constructed wetland

2012-12-19T16:46:51Z

Transformation of beneficially reused aluminium sludge to potential P and Al resource after employing as P-trapping material for wastewater treatment in constructed wetland Zhao, X.H.; Zhao, Y.Q.; Kearney, P. The phosphorus (P)-saturated aluminium sludge used as substrate in constructed wetland (CW) for P-rich wastewater treatment was investigated to recover P and Al through chemical precipitations of the P-extraction leachate of the used aluminium sludge. pH plays a key role in such the precipitation processes. The obtained compounds were identified with XRD, FTIR and SEM analyses. The results showed that over 99% PO43− could be recovered as hydroxyapatite by adding calcium chloride at pH of 13. The remaining Al could be fully recovered as amorphous aluminium hydroxide at pH of 7.0 or alternatively as tris(8-hydroxyquinolino)aluminium (Alq3) by adding suitable quantity of 8-hydroxyquinoline. Although the purity, structure, characteristics and production control of the compounds are worthy for further investigation, this study successfully developed a post-treatment methodology for beneficially reused aluminium sludge. The significance of this study is not only transferring aluminium sludge from “waste” to potential P and Al resources but also reducing the environmental risk of final disposal of used aluminium sludge.

Addiction as a Disease State

2012-12-05T15:32:55Z

Addiction as a Disease State Regan, Ciaran M.

The Formation of Medical Expertise

2012-12-05T15:26:18Z

The Formation of Medical Expertise Regan, Ciaran M.

Learning from interdisciplinarity

2012-12-05T14:46:13Z

Learning from interdisciplinarity Regan, Ciaran M.

The relationship between the group and the individual and the acquisition of native speaker variation patterns: a preliminary study

2012-11-29T15:01:41Z

The relationship between the group and the individual and the acquisition of native speaker variation patterns: a preliminary study Regan, Vera The relationship between group and individual has been explored within the variationist paradigm. In L1, group patterns of variation are replicated by the individual. Second language acquisition research is concerned with the individual learner, but second language acquisition variationist researchers tend to group learners. Little empirical evidence exists that such grouping is valid, given the importance of individual variation. This article investigates whether it is meaningful to group learners. This is a longitudinal, quantitative study of the acquisition of variation by Irish speakers of French L2 over three years, of which one is a year abroad experience. Participants are five advanced learners, twenty years old, with five years of French classes at secondary school and two at university. A computer (Varbrul) analysis shows similar patterns in group and individual, in the deletion of ne. Theoretical implications are that it is legitimate to apply group standards to individual speakers and that native speaker variation acquisition is linked to a prolonged stay in the native speaker community.

The Addicted Self: A Neuroscientific Perspective

2012-11-26T14:46:08Z

The Addicted Self: A Neuroscientific Perspective Regan, Ciaran M.

Can Metropolitan Housing Risk be Diversified? A Cautionary Tale from the Recent Boom and Bust

2012-11-23T16:55:45Z

Can Metropolitan Housing Risk be Diversified? A Cautionary Tale from the Recent Boom and Bust Cotter, John; Gabriel, Stuart A.; Roll, Richard Geographic diversification is fundamental to risk mitigation among investors and insurers of housing, mortgages, and mortgage-related derivatives. To characterize diversification potential, we provide estimates of integration, spatial correlation, and contagion among US metropolitan housing markets. Results reveal a high and increasing level of integration among US markets over the decade of the 2000s, especially in California. We apply integration results to assess the risk of alternative housing investment portfolios. Portfolio simulation indicates reduced diversification potential and increased risk in the wake of estimated increases in metropolitan housing market integration. Research findings provide new insights regarding the synchronous non-performance of geographically-disparate MBS investments during the late 2000s.

Commodity Futures Hedging, Risk Aversion and the Hedging Horizon

2012-11-23T16:13:07Z

Commodity Futures Hedging, Risk Aversion and the Hedging Horizon Conlon, Thomas; Gençay, Ramazan; Cotter, John This paper examines the impact of investor preferences on the optimal futures hedging strategy and associated hedging performance. Explicit risk aversion levels are often overlooked in hedging analysis. Applying a mean-variance hedging objective, the optimal futures hedging ratio is determined for a range of investor preferences on risk aversion, hedging horizon and expected returns. Wavelet analysis is applied to illustrate how investor time horizon shapes hedging strategy. Empirical results reveal substantial variation of the optimal hedge ratio for distinct investor preferences and are supportive of the hedging policies of real firms. Hedging performance is then shown to be strongly dependent on underlying preferences. In particular, investors with high levels of risk aversion and a short horizon reduce the risk of the hedge portfolio but achieve inferior utility in comparison to those with low risk aversion.

A Case Study of Collaboration and Reputation in Social Web Search.

2012-11-23T15:42:47Z

A Case Study of Collaboration and Reputation in Social Web Search. McNally, Kevin; O'Mahony, Michael P.; Coyle, Maurice; Briggs, Peter; Smyth, Barry Although collaborative searching is not supported by mainstream search engines, recent research has high- lighted the inherently collaborative nature of many web search tasks. In this paper, we describe HeyStaks (www.heystaks.com), a collaborative web search framework that is designed to complement mainstream search engines. At search time, HeyStaks learns from the search activities of other users and leverages this information to generate recommendations based on results that others have found relevant for similar searches. The key contribution of this paper is to extend the HeyStaks social search model by considering the search expertise, or reputation, of HeyStaks users and using this information to enhance the result recommendation process. In particular, we propose a reputation model for HeyStaks users that utilises the implicit collaboration events that take place between users as recommendations are made and selected. We describe a live-user trial of HeyStaks that demonstrates the relevance of its core recommendations and the ability of the reputation model to further improve recommendation quality. Our findings indicate that incorporating reputation into the recommendation process further improves the relevance of HeyStaks recommendations by up to 40%.

Retail in the Digital City

2012-11-23T15:22:04Z

Retail in the Digital City Keegan, Stephen; O'Hare, G. M. P. (Greg M. P.); O'Grady, Michael J. Conventional high street retailers face a multitude of challenges if they are to survive and thrive. Some of these difficulties arise from structural and economic issues; others may be sociological and demographic. However, to thrive, retailers must be perceived as being competitive, and must adopt innovative and invigorating strategies to maximise the potential of their situations while offsetting the limitations. In this paper, it is proposed that a judicious combination of low-cost Information and Communication Technologies (ICTs) could enable small retailers harness the beneﬁts of the information society and provide services congruent with the digital city concept. As an illustration of the issues involved, pertinent results from a systematic end-user evaluation of Easishop are discussed.

The Ambient Digital Library

2012-11-23T14:53:26Z

The Ambient Digital Library O'Grady, Michael J.; O'Hare, G. M. P. (Greg M. P.) Conventional digital libraries increasingly support remote access from mobile devices. However, the archetypical mobile user differs from the conventional user in a number of aspects; of these the most important is context. Synonymous with mobile computing is the context concept, and factoring the availability of select contextual elements into the design of digital libraries offers significant opportunities for adapting and personalising services for the mobile computing community. This paper proposes the Ambient Digital Library as a construct for integrating digital content, contextual parameters and user models. In this way, a digital library may be made more accessible to a broader category of mobile user.

Introducing social networks and brain computer interaction

2013-05-22T09:17:46Z

Introducing social networks and brain computer interaction Bourke, Steven; Healy, Graham; Smeaton, Alan F.; Smyth, Barry It is well known that the brain generates electrical patterns of activity in response to visual stimuli such as faces or any- thing that captures attention in a significant way. Signals of this type can be detected using an EEG (Electroencephalograph) system where we attach electrodes to the scalp and we amplify the detected signals and use a computer to capture them in real time. In this paper we examine the role that automatic sensing of brain activity may have on how users interact with interactive applications like Facebook. This offers a new opportunity for implicit feedback into such systems and in our work we focus on social networking applications. We demonstrate some of these implicit responses with experimental data captured while a user searched Facebook for photos of friends while being connected to an EEG. Finally, we discuss the implications that this kind of automatic implicit feedback may have on future design of such systems. iHCI 2012: Irish Human Computer Interaction Conference 2012, Galway, June 20 - 21

Plural mass nouns and the compositionality of number

2012-11-08T14:57:42Z

Plural mass nouns and the compositionality of number Acquaviva, Paolo It is true that, as is well known since Allan (1980), mass and count are best seen as preferences rather than absolute values for lexical items; for instance, clothes cannot be governed by a numeral, but it tolerates the count quantifier a few. Even so, the existence of plurals that, at the very least, share some properties with mass nouns, raises questions about the chain of reasoning I have sketched out above. In fact, the assumption that plural nouns must refer to collections of individuals is simply wrong, even in languages where the number category would appear to correlate straightforwardly with the contrast between one and more than one. My first goal here will be to substantiate this empirical claim (section 2). Secondly, I will address in section 3 a theoretical question that cannot even be posed, let alone answered, without realizing that plural nouns can be non-count: the relation between semantic and morphological structure in mass plurals, whose interpretation does not seem to accord with the interpretation of the plural affix. How can a noun modified by this affix fail to denote non-singleton sets and still retain a compositional interpretation? The answer is that mass plurals are indeed semantically plural, but they refer to manifold complexes of non-individual parts. The familiar onemany contrast of book vs. books is not a primitive, defining trait of plurality, but a consequence of the semantics of the noun and of the way plurality combines with it. Variation along either of these two dimensions can bring about different readings—which are the empirical concern of this paper.

Towards the Improved Discovery and Design of Functional Peptides: Common Features of Diverse Classes Permit Generalized Prediction of Bioactivity

2012-11-07T15:27:40Z

Towards the Improved Discovery and Design of Functional Peptides: Common Features of Diverse Classes Permit Generalized Prediction of Bioactivity Mooney, Catherine; Haslam, Niall J.; Pollastri, Gianluca; Shields, Denis C. The conventional wisdom is that certain classes of bioactive peptides have specific structural features that endow their particular functions. Accordingly, predictions of bioactivity have focused on particular subgroups, such as antimicrobial peptides. We hypothesized that bioactive peptides may share more general features, and assessed this by contrasting the predictive power of existing antimicrobial predictors as well as a novel general predictor, PeptideRanker, across different classes of peptides.We observed that existing antimicrobial predictors had reasonable predictive power to identify peptides of certain other classes i.e. toxin and venom peptides. We trained two general predictors of peptide bioactivity, one focused on short peptides (4-20 amino acids) and one focused on long peptides (>20 amino acids). These general predictors had performance that was typically as good as, or better than, that of specific predictors. We noted some striking differences in the features of short peptide and long peptide predictions, in particular, high scoring short peptides favour phenylalanine. This is consistent with the hypothesis that short and long peptides have different functional constraints, perhaps reflecting the difficulty for typical short peptides in supporting independent tertiary structure.We conclude that there are general shared features of bioactive peptides across different functional classes, indicating that computational prediction may accelerate the discovery of novel bioactive peptides and aid in the improved design of existing peptides, across many functional classes. An implementation of the predictive method, PeptideRanker, may be used to identify among a set of peptides those that may be more likely to be bioactive.

Roots, categories, and nominal concepts

2012-10-16T16:02:02Z

Roots, categories, and nominal concepts Acquaviva, Paolo This paper investigates what is specifically nominal in lexical semantics and how it relates to nouns as morphosyntactic objects. Nouns are argued to refer primarily to kind-level sorts, which define categories of entities in the speakers' conceptualization. This notion is characterized in semantic, ontological, and cognitive terms. Not all nominalized properties are concepts; in particular, not transparent deverbal nominalizations. Concepts thus provide a substantive notion of nominality not coextensive with the morphosyntactic one. Evidence is presented for the explanatory value of nominal concepts, as the semantic contribution of noun stems in word formation and in non-standard modification patterns like "plastic flower". Concepts also express semantic restrictions on affixation ("ornamental", but "employmental"). Finally, concepts are the value of nouns as whole complexes, not of their roots. This accords with the view that lexical categories have content, but roots are category-free.

Automatic Detection of Tackles in Elite Level Rugby Union

2012-10-16T15:31:52Z

Automatic Detection of Tackles in Elite Level Rugby Union Kelly, Daniel; Coughlan, Garrett; Green, Brian; Caulfield, Brian Elite rugby union teams currently employ technology in order to monitor and evaluate the physical demands of training and games on their players. Tackling has been shown to be the most common cause of injury in rugby union (Fuller et al. (2007a), Garraway et al. (1999)). However, current player monitoring technology does not effectively evaluate player tackling measurements. Sensing devices, currently being used by elite rugby union teams, contain a GPS receiver and a 3-axis accelerometer. GPS has been utilized to measure player speed and distance. Accelerometers, on the other hand, have an under-utilized potential to analyse body impact and collisions. Presented at the IRFU Sports Medicine Conference: Injury Prevention in Rugby Union, May 17th-19th, 2012 in the AVIVA Stadium, Dublin

Aggregating Content and Network Information to Curate Twitter User Lists

2012-10-16T14:03:36Z

Aggregating Content and Network Information to Curate Twitter User Lists Greene, Derek; Sheridan, Gavin; Smyth, Barry; Cunningham, Pádraig Twitter introduced user lists in late 2009, allowing users to be grouped according to meaningful topics or themes. Lists have since been adopted by media outlets as a means of organising content around news stories. Thus the curation of these lists is important - they should contain the key information gatekeepers and present a balanced perspective on a story. Here we address this list curation process from a recommender systems perspective. We propose a variety of criteria for generating user list recommendations, based on content analysis, network analysis, and the "crowdsourcing" of existing user lists. We demonstrate that these types of criteria are often only successful for datasets with certain characteristics. To resolve this issue, we propose the aggregation of these different "views" of a news story on Twitter to produce more accurate user recommendations to support the curation process. ACM RecSys 2012 Workshop on Recommender Systems & The Social Web, 9 September, 2012, Dublin

Zn, Fe and S isotope fractionation in a large hydrothermal system

2012-10-16T13:44:12Z

Zn, Fe and S isotope fractionation in a large hydrothermal system Gagnevin, Damien; Boyce, Adrian; Barrie, Craig; Menuge, Julian; Blakeman, Robert The genesis of hydrothermal ore deposits is of crucial economic importance. This study investigates the extent, causes and consequences of zinc and iron isotope fractionation in a large hydrothermal system at the world-class Navan Zn–Pb orebody, Ireland. Large variations in Zn, Fe and S isotope compositions have been measured in microdrilled sphalerite (ZnS) at the millimetre scale. d66Zn and d56Fe display a well-defined positive correlation and both also correlate with d34S. These relationships represent the combined effects of kinetic Zn and Fe isotope fractionation during sphalerite precipitation, and S isotope variation through mixing of hot, metal-rich hydrothermal fluids and cool, bacteriogenic sulfide-bearing brines. Combined with S isotope data, d56Fe and d66Zn data on mine concentrates confirm that hydrothermal sulfide is a minor component of the overall deposit signature. Our data suggest that incoming pulses of metal-rich hydrothermal fluid triggered sulfide mineralisation, and that rapid precipitation of sphalerite from hydrothermal fluids will lead to strong kinetic fractionation of Zn and Fe isotopes at very short time and length scales, thereby limiting the use of Fe and Zn isotopes as exploration tools within deposits, but revealing the possibility of detecting new deposits from isotopically heavy Zn–Fe geochemical halos.

Downside Risk and the Energy Hedger’s Horizon

2012-10-16T13:32:08Z

Downside Risk and the Energy Hedger’s Horizon Conlon, Thomas; Cotter, John In this paper, we explore the impact of investor time-horizon on an optimal downside hedged energy portfolio. Previous studies have shown that minimum-variance hedging effectiveness improves for longer horizons using variance as the performance metric. This paper investigates whether this result holds for different hedging objectives and effectiveness measures. A wavelet transform is applied to calculate the optimal heating oil hedge ratio using a variety of downside objective functions at different time-horizons. We demonstrate decreased hedging effectiveness for increased levels of uncertainty at higher confidence intervals. Moreover, for each of the different hedging objectives and effectiveness measures studied, we also demonstrate increasing hedging effectiveness at longer horizons. While small differences in effectiveness are found across the different hedging objectives, time horizon effects are found to dominate confirming the importance of considering the hedgers horizon. The findings suggest that while downside risk measures are useful in the computation of an optimal hedge ratio that accounts for unwanted negative returns, hedging horizon and confidence intervals should also be given careful consideration by the energy hedger.

Influences on flood frequency distributions in Irish river catchments

2013-05-16T11:46:21Z

Influences on flood frequency distributions in Irish river catchments Ahilan, Sangaralingam; Bruen, Michael; O'Sullivan, J. J. This study explores influences on flood frequency distributions in Irish rivers. Generalised Extreme Value (GEV) type I distributions are recommended in Ireland for estimating flood quantiles. This paper presents the findings of an investigation that identified the GEV statistical distributions that best fit the annual maximum (AM) data series extracted from 172 gauging stations of 126 rivers in Ireland. Analysis of these data was undertaken to explore hydraulic and hydro-geological factors that influence flood frequency distributions. A hierarchical approach of increasing statistical power that used probability plots, moment and L-moment diagrams, the Hosking goodness of fit algorithm and a modified Anderson-Darling (A-D) statistical test was followed to determine whether a type I, type II or type III distribution was valid. Results of the Hosking et al. method indicated that of the 143 stations with flow records exceeding 25 years, data for 95 (67%) was best represented by GEV type I distributions and a further 9 (6%) and 39 (27%) stations followed type II and type III distributions respectively. Type I, type II and type III distributions were determined for 83 (58%), 16 (11%) and 34 (24%) stations respectively using the modified A-D method (data from 10 stations was not represented by GEV family distributions). The influence of karst terrain on these flood frequency distributions was assessed by incorporating results on an Arc-GIS platform showing karst features and using Monte Carlo simulations to assess the significance of the number and clustering of the observed distributions. Floodplain effects were identified by using two-sample t-tests to identify statistical correlations between the distributions and catchment properties that are indicative of strong floodplain activity. The data reveals that type I distributions are spatially well represented throughout the country. While also well represented throughout the country, the majority of type III distributions appear in areas where attenuation influences from floodplains are likely. The majority of type II distributions appear in a single cluster in a region in the west of the country that is underlain by karst but importantly, is characterised by shallow of glacial drift with frequent exposures of rock outcrops. The presence of karst in river catchments would be expected to provide additional subsurface storage and in this regard, type III distributions might be expected. The prevalence of type II distributions in this area reflects the finite nature of this storage. For prolonged periods of rainfall, rising groundwater levels will fill karst voids, remove subsurface storage and contribute to recharge related sinkhole flooding. Situations where rainfall intensities exceed karst percolation rates also produce high levels of surface runoff (discharge related flooding) that can promote type II distributions in nearby river catchments. Results therefore indicate that in some instances, assuming type I distributions is incorrect and may result in erroneous estimates of flood quantiles at these locations. Where actual data follows a type II distribution, flood quantiles may be underestimated by in excess of 35% and for type III distributions, overestimates by over 25% can occur.

A Self-adaptive Unifying Mechanism For Autonomous Energy Management In Wireless Sensor Networks

2012-09-05T15:46:56Z

A Self-adaptive Unifying Mechanism For Autonomous Energy Management In Wireless Sensor Networks Xu, Lina; O'Hare, G. M. P. (Greg M. P.); Collier, Rem; Murdoch, Olga 4th Workshop on Adaptive and Reconfigurable Embedded Systems APRES 2012. Beijing, China, April 16 2012

Profile-based short linear protein motif discovery.

2012-09-05T15:37:09Z

Profile-based short linear protein motif discovery. Haslam, Niall J.; Shields, Denis C. Background Short linear protein motifs are attracting increasing attention as functionally independent sites, typically 3-10 amino acids in length that are enriched in disordered regions of proteins. Multiple methods have recently been proposed to discover over-represented motifs within a set of proteins based on simple regular expressions. Here, we extend these approaches to profile-based methods, which provide a richer motif representation. Results The profile motif discovery method MEME performed relatively poorly for motifs in disordered regions of proteins. However, when we applied evolutionary weighting to account for redundancy amongst homologous proteins, and masked out poorly conserved regions of disordered proteins, the performance of MEME is equivalent to that of regular expression methods. However, the two approaches returned different subsets within both a benchmark dataset, and a more realistic discovery dataset. Conclusions Profile-based motif discovery methods complement regular expression based methods. Whilst profile-based methods are computationally more intensive, they are likely to discover motifs currently overlooked by regular expression methods.

Towards Holistic Activity Modeling and Behavioral Analyses

2012-09-05T15:28:17Z

Towards Holistic Activity Modeling and Behavioral Analyses Wan, Jie; O'Grady, Michael J.; O'Hare, G. M. P. (Greg M. P.) As the age profile of many societies continues to increase, supporting health, both mental and physical, is of increasing importance if independent living is to be maintained. Sensing and, ultimately, recognizing activities of daily living has been perceived as a prerequisite for detecting tasks that people avoid or find increasingly difficult to perform, as well as being indicators of certain illnesses. To date, extensive research efforts have been made on activity monitoring, recognition and assistance in indoor scenarios, frequently through smart home initiatives. However, the scenarios outside of the home have not received a similar degree of attention from the research community. This paper advocates a need for platforms that enable activity recognition in a range of environments, thus enabling the construction of more complex yet realistic activity models and behavior patterns. The design of a prototype supporting an integrated approach to sensor data capture and activity model construction is proposed. The application domain is that of dementia. 6th International workshop on Ubiquitous health and wellness (UbiHealth 2012), in the Pervasive 2012 Conference, Newcastle UK

Biotransformation of fluorobiphenyl by Cunninghamella elegans

2012-09-04T15:59:46Z

Biotransformation of fluorobiphenyl by Cunninghamella elegans Amadio, Jessica; Murphy, Cormac D. The fungus Cunninghamella elegans is a useful model of human catabolism of xenobiotics. In this paper, the biotransformation of fluorinated biphenyls by C. elegans was investigated by analysis of the culture supernatants with a variety of analytical techniques. 4-Fluorobiphenyl was principally transformed to 4-fluoro-4′-hydroxybiphenyl, but other mono- and dihydroxylated compounds were detected in organic extracts by gas chromatography–mass spectrometry. Additionally, fluorinated water-soluble products were detected by 19F NMR and were identified as sulphate and β-glucuronide conjugates. Other fluorobiphenyls (2-fluoro-, 4,4′-difluoro- and 2,3,4,5,6-pentafluoro-biphenyl) were catabolised by C. elegans, yielding mono- and dihydroxylated products, but phase II metabolites were detected from 4,4′-difluorobiphenyl only.

Bacterial defluorination of 4-fluoroglutamic acid

2012-09-04T15:44:28Z

Bacterial defluorination of 4-fluoroglutamic acid Donnelly, Clár; Murphy, Cormac D. Fluorinated amino acids are used as enzyme inhibitors, mechanistic probes and in the production of pharmacologically active peptides. Because enantiomerically pure 4-fluoroglutamate is difficult to prepare, the selective degradation of the l-isomer is a potentially convenient method of obtaining d-4-fluoroglutamate from the racemate. In this paper, we describe our investigations on the degradation of 4-fluoroglutamate by bacteria. Fluoride ion was detected in resting-cell cultures of a number of bacteria that were incubated with racemic 4-fluoroglutamate. Analysis of the culture supernatants by chiral gas chromatography–mass spectrometry revealed that only the l-isomer was degraded. The degradation of 4-fluoroglutamate was also examined in cell-free extracts of Streptomyces cattleya and Proteus mirabilis, and it was observed that equimolar concentrations of fluoride ion and ammonia were generated. The activity was located in the soluble fraction of cell extracts, thus is not related to the l-2-amino-4-chloro-4-pentenoic acid dehydrochlorinase previously identified in membrane fractions of P. mirabilis.

Design and development of a low-cost thermal response rig

2012-09-03T13:45:45Z

Design and development of a low-cost thermal response rig Hemmingway, Phil; Long, Michael (Michael M.) A thermal response test (TRT) is a controlled insitu test during which a known quantity of heat energy is injected into a closed loop heat-exchanger pipe while the heat dissipation rate into the surrounding ground is monitored. Results from a test can be interpreted to determine a number of ground thermal parameters with are vital design requirements for any medium to large scale ground source energy system. This paper describes the design and construction of a low cost TRT rig and compares the results obtained from a test using the constructed rig and a commercially built rig in order to evaluate the accuracy of the constructed equipment. The TRT rig is designed in accordance with the following principles: keep construction costs low, improve the cost-efficiency of TRT testing by incorporating remote data transmission capability and ensure attainment of sufficient accuracy to satisfy the design requirements of ground source energy systems. Analysis of data collected by the TRT rigs result in a calculated thermal conductivity of 1.9 W/mK in both cases. This value falls within the range expected for the tested geological formation and confirms the accuracy of both test rigs.

Sensor Web Interaction

2012-08-24T15:06:17Z

Sensor Web Interaction O'Hare, G. M. P. (Greg M. P.); Muldoon, Conor; O'Grady, Michael J.; Collier, Rem; Murdoch, Olga; Carr, Dominic Ubiquitous sensing fuses the concepts of intelligent systems with ubiquitous computing in the development of novel sensor web applications, whereby the interaction of multiple disparate autonomous artefacts is a key requirement. In this paper, we present SIXTH, which is a middleware infrastructure for Ubiquitous Sensing that facilitates, and supports, the development and deployment of Sensor Web applications. SIXTH has been designed to be extensible, with provisions for user definable data retention policies, custom sensor data representations, and custom sensor node representations, whilst still providing a rich set of default behaviours. Within SIXTH, support is provided for the development and interaction of applications that incorporate both physical and cyber (virtual server side) sensors. With a view to supporting intelligent, in network, interaction policies, whereby sensor nodes must negotiate and coordinate their behaviour, the system has been designed to operate in conjunction with Agent Factory Micro Edition (AFME). AFME is a minimised footprint intelligent agent platform designed for resource constrained devices. It is based on the standard Agent Factory platform, which was developed for desktop machines, and is representative of a class of agent systems, which are referred to as Agent Oriented Programming frameworks. The paper discusses a ubiquitous mapping application that was developed using the middleware.

Embedding Agents within Ambient Intelligent Applications

2012-08-20T16:39:39Z

Embedding Agents within Ambient Intelligent Applications O'Hare, G. M. P. (Greg M. P.); Collier, Rem; Dragone, Mauro; O'Grady, Michael J.; Muldoon, Conor; De J. Montoya, Alcides This chapter reflects upon the challenges that confront the deployment of Ambient Intelligence (AmI) applications. Ambient Intelligence demands that everyday artefacts be imbued with intelligent reasoning capabilities together with the capacity for collaborative intelligent behaviour. Traditional ambient devices do not provide the requisite computational platform to support such requirements. With the ongoing developments of ubiquitous devices, however, the situation is changing. This chapter discusses a software stack, which supports the needs of ambient applications that incorporate embedded intelligence.

Generating recommendations for consensus negotiation in group personalization services

2012-08-20T16:29:20Z

Generating recommendations for consensus negotiation in group personalization services Salamó, Maria; McCarthy, Kevin; Smyth, Barry There are increasingly many personalization services in ubiquitous computing environments that involve a group of users rather than individuals. Ubiquitous commerce is one example of these environments. Ubiquitous commerce research is highly related to recommender systems that have the ability to provide even the most tentative shoppers with compelling and timely item suggestions. When the recommendations are made for a group of users, new challenges and issues arise to provide compelling item suggestions. One of the challenges a group recommender system must cope with is the potentially conflicting preferences of multiple users when selecting items for recommendation. In this paper we focus on how individual user models can be aggregated to reach a consensus on recommendations. We describe and evaluate nine different consensus strategies and analyze them to highlight the benefits of group recommendation using live-user preference data. Moreover, we show that the performance is significantly different among strategies.

Automatic detection of collisions in elite level rugby union using a wearable sensing device

2012-10-16T15:25:06Z

Automatic detection of collisions in elite level rugby union using a wearable sensing device Kelly, Daniel; Coughlan, Garrett; Green, Brian; Caulfield, Brian Elite rugby union teams currently employ the latest technology to monitor and evaluate the physical demands of training and games on their players. Tackling has been shown to be the most common cause of injury in rugby union, yet current player monitoring technology does not effectively evaluate player tackling measurements. Currently, to evaluate measurements specific to player tackles, a time-consuming manual analysis of player sensor data and video footage is required. The purpose of this work is to investigate tackle modeling techniques which can be utilised to automatically detect player tackles and collisions using sensing technology already being used by elite international and club level rugby union teams. This paper discusses issues relevant to automatic tackle analysis, describes a technique to detect tackles using sensing data and validates the technique by comparing automatically detected collisions to manually labeled collisions using data from elite club and international level players. The results of the validation show that the system is able to consistently identify collisions with very few false posi- tives and false negatives, achieving a recall and precision rating of 0.933 and 0.958, respectively. The aim is that the automatically detected tackles can provide coaching, medical and strength and conditioning staff with objective tackle-specific measurements, in real time, which can be used in injury prevention and rehabilitation strategies.

Sensing the sensor web

2012-08-20T15:53:37Z

Sensing the sensor web Wan, Jie; O'Grady, Michael J.; O'Hare, G. M. P. (Greg M. P.) The maturity of pervasive computing and Wireless Sensor Networks (WSNs) enables the development of smart environments in many scenarios, including surveillance and environmental monitoring. Extensive research efforts are being undertaken in sensor perception, data capture, management and interpretation. Such developments are a prerequisite for paradigms such as pervasive sensing and crowd-sourcing services. For mobile users, the issues of dynamic sensor discovery, data interpretation and visualization must be addressed if such services are to be realized in practice. This paper explores the genesis of a generic framework for heterogeneous sensor access and data visualization in remote contexts. Paper presented at Pervasive Computing and Communications Workshops (PERCOM Workshops) 2012, 19th March, Lugano, Switzerland

Enabling Intelligence on a Wireless Sensor Network Platform

2012-08-20T15:45:23Z

Enabling Intelligence on a Wireless Sensor Network Platform O'Grady, Michael J.; Angove, Philip; Magnin, W; O'Hare, G. M. P. (Greg M. P.); O'Flynn, Brendan; Barton, John; O'Mathuna, Cian Conventional Wireless Sensor Networks (WSNs) usually adopt a centralised approach to data processing and interpretation primarily due to the limited computation and energy resources available on sensor nodes. These constraints limits the potential of intelligent techniques to data analy- sis and such activities on the centralised host. In contrast, Intelligent WSNs (iWSNs) will be significantly more powerful thus enabling the harnessing of intelligent techniques for diverse purposes. One such purpose is the practical realisation of smart environments, and facilitating mobility and interaction with the inhabitants of such environments. As a step in this direction, this paper presents the design of an iWSN sensor node platform that enables the hosting of lightweight Artificial Intelligence (AI) frameworks whilst enabling the ubiquitous energy constraints be quantified, mitigated and managed. Paper presented at Practical Applications of Agents and Multi-Agent Systems 10th International Conference on Practical Applications of Agents and Multi-Agent Systems 28th of March, Salamanca, Spain

Browsing the Sensor Web : Pervasive Access for Wide-area Wireless Sensor Networks

2012-08-20T15:36:00Z

Browsing the Sensor Web : Pervasive Access for Wide-area Wireless Sensor Networks Wan, Jie; O'Grady, Michael J.; O'Hare, G. M. P. (Greg M. P.); Colakov, Todor Wireless Sensor Networks (WSNs) are almost exclusively regarded as data gathering entities. Various sensed data elements are captured and routed back to a central server for processing, visualization and interpretation. However, it can be realistically conjectured that scenarios will increasingly emerge that demand a facility for ad-hoc interaction with individual sensor nodes. Moreover, such interaction will occur in the physical environment in close proximity to where the sensor node is physically located. In this paper, the need for in-situ ad-hoc interaction is motivated. A methodology for facilitating such interaction is presented, and the implementation of a sensor browser is described. Paper presented at Sensornets 2012, 1st International Conference on Sensor Networks, 24-26 February, 2012, Rome, Italy

Genetic Programming for the Induction of Seasonal Forecasts: A Study on Weather-derivatives

2012-08-20T15:28:04Z

Genetic Programming for the Induction of Seasonal Forecasts: A Study on Weather-derivatives Agapitos, Alexandros; O'Neill, Michael; Brabazon, Anthony The last ten years has seen the introduction and rapid growth of a market in weather derivatives, financial instruments whose payoffs are determined by the outcome of an underlying weather metric. These instruments allow organisations to protect themselves against the commercial risks posed by weather fluctuations and also provide investment opportunities for financial traders. The size of the market for weather derivatives is substantial, with a survey suggesting that the market size exceeded $45.2 Billion in 2005/2006 with most contracts being written on temperature-based metrics. A key problem faced by buyers and sellers of weather derivatives is the determination of an appropriate pricing model (and resulting price) for the financial instrument. A critical input into the pricing model is an accurate forecast of the underlying weather metric. In this study we induce seasonal forecasting temperature models by means of a Machine Learning algorithm. Genetic Programming (GP) is applied to learn an accurate, localised, long-term forecast of a temperature profile as part of the broader process of determining appropriate pricing model for weather-derivatives. Two different approaches for GP-based time-series modelling are adopted. The first is based on a simple system identification approach whereby the temporal index of the time-series is used as the sole regressor of the evolved model. The second is based on iterated single-step prediction that resembles autoregressive and moving average models in statistical time-series modelling. The major issue of effective model generalisation is tackled though the use of an ensemble learning technique that allows a family of forecasting models to be evolved using different training sets, so that predictions are formed by averaging the diverse model outputs. Empirical results suggest that GP is able to successfully induce seasonal forecasting models, and that search-based autoregressive models compose a more stable unit of evolution in terms of generalisation performance for the three datasets considered. In addition, the use of ensemble learning of 5-model predictors enhanced the generalisation ability of the system as opposed to single-model prediction systems. On a more general note, there is an increasing recognition of the utility of evolutionary methodologies for the modelling of meteorological, climatic and ecological phenomena, and this work also contributes to this literature.

Review of Statistical Network Analysis: Models, Algorithms, and Software

2012-08-17T16:25:41Z

Review of Statistical Network Analysis: Models, Algorithms, and Software Salter-Townshend, Michael; White, Arthur; Gollini, Isabella; Murphy, Thomas Brendan The analysis of network data is an area that is rapidly growing, both within and outside of the discipline of statistics. This review provides a concise summary of methods and models used in the statistical analysis of network data, including the Erdos–Renyi model, the exponential family class of network models, and recently developed latent variable models. Many of the methods and models are illustrated by application to the well-known Zachary karate dataset. Software routines available for implementing methods are emphasized throughout. The aim of this paper is to provide a review with enough detail about many common classes of network models to whet the appetite and to point the way to further reading.