J-PMCRI: a methodology for inducing pre-pruned modular classification rules

Inducing rules from very large datasets is one of the most challenging areas in data mining. Several approaches exist to scaling up classification rule induction to large datasets, namely data reduction and the parallelisation of classification rule induction algorithms. In the area of parallelisation of classification rule induction algorithms most of the work has been concentrated on the Top Down Induction of Decision Trees (TDIDT), also known as the ‘divide and conquer’ approach. However powerful alternative algorithms exist that induce modular rules. Most of these alternative algorithms follow the ‘separate and conquer’ approach of inducing rules, but very little work has been done to make the ‘separate and conquer’ approach scale better on large training data. This paper examines the potential of the recently developed blackboard based J-PMCRI methodology for parallelising modular classification rule induction algorithms that follow the ‘separate and conquer’ approach. A concrete implementation of the methodology is evaluated empirically on very large datasets.

A trading strategy based on the lead–lag relationship between the spot index and futures contract for the FTSE 100

This paper examines the lead–lag relationship between the FTSE 100 index and index futures price employing a number of time series models. Using 10-min observations from June 1996–1997, it is found that lagged changes in the futures price can help to predict changes in the spot price. The best forecasting model is of the error correction type, allowing for the theoretical difference between spot and futures prices according to the cost of carry relationship. This predictive ability is in turn utilised to derive a trading strategy which is tested under real-world conditions to search for systematic profitable trading opportunities. It is revealed that although the model forecasts produce significantly higher returns than a passive benchmark, the model was unable to outperform the benchmark after allowing for transaction costs.

Change management in practice: an ethnographic study of changes to contract requirements on a hospital project

Changes to client requirements are inevitable during construction. Industry discourse is concerned with minimizing and controlling changes. However, accounts of practices involved in making changes are rare. In response to calls for more research into working practices, an ethnographic study of a live hospital project was undertaken to explore how changes are made. A vignette of a meeting exploring the investigation of changes illustrates the issues. This represents an example from the ethnographic fieldwork, which produced many observations. There was a strong emphasis on using change management procedures contained within the contract to investigate changes, even when it was known that the change was not required. For the practitioners, this was a way of demonstrating best practice, transparent and accountable decision-making regarding changes. Hence, concerns for following procedures sometimes overshadowed considerations about whether or not a change was required to improve the functionality of the building. However, the procedures acted as boundary objects between the communities of practice involved on the project by coordinating the work of managing changes. Insights suggest how contract procedures facilitate and impede the making of changes, which can inform policy guidance and contract drafting.

Exogenous alpha-Synuclein decreases raft partitioning of Cav2.2 channels inducing dopamine release

alpha-Synuclein is thought to regulate neurotransmitter release through multiple interactions with presynaptic proteins, cytoskeletal elements, ion channels, and synaptic vesicles membrane. alpha-Synuclein is abundant in the presynaptic compartment, and its release from neurons and glia has been described as responsible for spreading of alpha-synuclein-derived pathology. alpha-Synuclein-dependent dysregulation of neurotransmitter release might occur via its action on surface-exposed calcium channels. Here, we provide electrophysiological and biochemical evidence to show that alpha-synuclein, applied to rat neurons in culture or striatal slices, selectively activates Cav2.2 channels, and said activation correlates with increased neurotransmitter release. Furthermore, in vivo perfusion of alpha-synuclein into the striatum also leads to acute dopamine release. We further demonstrate that alpha-synuclein reduces the amount of plasma membrane cholesterol and alters the partitioning of Cav2.2 channels, which move from raft to cholesterol-poor areas of the plasma membrane. We provide evidence for a novel mechanism through which alpha-synuclein acts from the extracellular milieu to modulate neurotransmitter release and propose a unifying hypothesis for the mechanism of alpha-synuclein action on multiple targets: the reorganization of plasma membrane microdomains.

New opportunities for secure communication networks using shaped femtosecond laser pulses inducing filamentation processes in the atmosphere

The current study discusses new opportunities for secure ground to satellite communications using shaped femtosecond pulses that induce spatial hole burning in the atmosphere for efficient communications with data encoded within super-continua generated by femtosecond pulses. Refractive index variation across the different layers in the atmosphere may be modelled using assumptions that the upper strata of the atmosphere and troposphere behaving as layered composite amorphous dielectric networks composed of resistors and capacitors with different time constants across each layer. Input-output expressions of the dynamics of the networks in the frequency domain provide the transmission characteristics of the propagation medium. Femtosecond pulse shaping may be used to optimize the pulse phase-front and spectral composition across the different layers in the atmosphere. A generic procedure based on evolutionary algorithms to perform the pulse shaping is proposed. In contrast to alternative procedures that would require ab initio modelling and calculations of the propagation constant for the pulse through the atmosphere, the proposed approach is adaptive, compensating for refractive index variations along the column of air between the transmitter and receiver.

Contract cheating & the market in essays

We conduct the first empirical economic investigation of the decision to cheat by University students. We investigate student demand for essays, using hypothetical discrete choice experiments in conjunction with consequential Holt-Laury gambles to derive subjects risk preferences. Students stated willingness to participate in the essay market, and their valuation of purchased essays, vary with the characteristics of student and institutional environment. Risk preferring students, those working in a non-native language, and those believing they will attain a lower grade are willing to pay more. Purchase likelihoods and essay valuations decline as the probability of detection and associated penalty increase.

English Contract Law and the Great War: the development of a doctrine of frustration

This article examines changes that occurred in English contract law as a result of the demands made upon Great Britain by the Great War. The focus is on the development of the doctrine of frustration in English law. In particular, it is argued that the development of the doctrine of frustration was fashioned from internal legal forces in the form of both existing case law and emergency legislation in response to the demands placed upon the nation by a global war. The way in which the doctrine of frustration developed during the Great War arose as a direct result of the way in which Britain chose to meet the logistical demands created by the way it fought the Great War.

Ibuprofen inhibits migration and proliferation of human coronary artery smooth muscle cells by inducing a differentiated phenotype: role of peroxisome proliferator-activated receptor y

Objectives: The search for agents that are capable of preventing restenosis and reduce the risk of late thrombosis is of utmost importance. In this study we aim to evaluate the in vitro effects of ibuprofen on proliferation and migration of human coronary artery smooth muscle cells (HCASMCs) and on human coronary artery endothelial cells (HCAECs) migration. Methods: Cell proliferation was evaluated by direct cell counting using trypan blue exclusion. Cell migration was assessed by wound healing “scratch” assay and by time lapse video-microscopy. Protein expression was assessed by immunoblotting, and morphological changes were studied by immunocytochemistry. The involvement of the PPARγ pathway was studied with the selective agonist troglitazone, and the use of highly selective antagonists of PPARγ such as PGF2α and GW9662. Results: We demonstrate that ibuprofen inhibits proliferation and migration of HCASMCs and induces a switch in HCASMCs towards a differentiated and contractile phenotype, and that these effects are mediated through the PPARγ pathway. Importantly we also show that the effects of ibuprofen are cell type specific as it does not affect migration and proliferation of endothelial cells. Conclusions: Taken together, our results suggest that ibuprofen could be an effective drug for the development of novel drug eluting stents, which could lead reduced rates of restenosis and potentially other complications of DES stent implantation.

Training and the commitment of outsourced information technologies' workers: psychological contract fulfillment as a mediator

Outsourced workers in information technologies (IT) generally have high skills and a high value on the job market. Their IT outsourcing organizations are likely to provide them with training, in the first place for skill development, but perhaps also as a way to bind the workers to them. This can be understood along the role of the psychological contract. Outsourced IT workers may see training as a fulfillment of their psychological contract. Accordingly, we hypothesize that psychological contract fulfillment mediates the relationship between training and affective commitment to the IT outsourcer. This was tested in a sample of 158 Portuguese outsourced IT workers. The results showed that employees who considered that they were receiving good training opportunities felt a greater affective commitment to their IT outsourcers. This relationship was mediated by the fulfillment of the relational psychological contract.

Contingencies of contingent employment: psychological contract, job insecurity and employability of contracted workers

Drawing on psychological contract literature, the present study examines the emerging contingent employment relationships, which involve the contracted workers, the employment agency and the client organization on whose premises these employees work. This sample includes eighty-eight white-collar employees working for four Portuguese agencies. The results suggest that the perceived fulfilment of client?s obligations relates positively to the perceived fulfilment of agency?s obligations and that these constructs are independent of one another. Furthermore, as expected, we have found that the perception of job insecurity relates negatively to the fulfilment of agency?s obligations. No relationship was found between employability and the perceived fulfilment of client?s obligations. The results have implications for practitioners and future research.

Quick abnormal-bid-detection method for construction contract auctions

Noncompetitive bids have recently become a major concern in both public and private sector construction contract auctions. Consequently, several models have been developed to help identify bidders potentially involved in collusive practices. However, most of these models require complex calculations and extensive information that is difficult to obtain. The aim of this paper is to utilize recent developments for detecting abnormal bids in capped auctions (auctions with an upper bid limit set by the auctioner) and extend them to the more conventional uncapped auctions (where no such limits are set). To accomplish this, a new method is developed for estimating the values of bid distribution supports by using the solution to what has become known as the German Tank problem. The model is then demonstrated and tested on a sample of real construction bid data, and shown to detect cover bids with high accuracy. This paper contributes to an improved understanding of abnormal bid behavior as an aid to detecting and monitoring potential collusive bid practices.