Distinct contrast response functions in striate and extra-striate regions of visual cortex revealed with magnetoencephalography (MEG)

Objective: To spatially and temporally characterise the cortical contrast response function to pattern onset stimuli in humans. Methods: Magnetoencephalography (MEG) was used to investigate the human cortical contrast response function to pattern onset stimuli with high temporal and spatial resolution. A beamformer source reconstruction approach was used to spatially localise and identify the time courses of activity at various visual cortical loci. Results: Consistent with the findings of previous studies, MEG beamformer analysis revealed two simultaneous generators of the pattern onset evoked response. These generators arose from anatomically discrete locations in striate and extra-striate visual cortex. Furthermore, these loci demonstrated notably distinct contrast response functions, with striate cortex increasing approximately linearly with contrast, whilst extra-striate visual cortex followed a saturating function. Conclusions: The generators that underlie the pattern onset visual evoked response arise from two distinct regions in striate and extra-striate visual cortex. Significance: The spatially, temporally and functionally distinct mechanisms of contrast processing within the visual cortex may account for the disparate results observed across earlier studies and assist in elucidating causal mechanisms of aberrant contrast processing in neurological disorders. © 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Characterising the central mechanisms of sensory modulation in human swallowing motor cortex

Objective: Pharyngeal stimulation can induce remarkable increases in the excitability of swallowing motor cortex, which is associated with short-term improvements in swallowing behaviour in dysphagic stroke patients. However, the mechanism by which this input induces cortical change remains unclear. Our aims were to explore the stimulus-induced facilitation of the cortico-bulbar projections to swallowing musculature and examine how input from the pharynx interacts with swallowing motor cortex. Methods: In 8 healthy subjects, a transcranial magnetic stimulation (TMS) paired-pulse investigation was performed comprising a single conditioning electrical pharyngeal stimulus (pulse width 0.2 ms, 240 V) followed by cortical TMS at inter-stimulus intervals (ISI) of 10-100 ms. Pharyngeal sensory evoked potentials (PSEP) were also measured over the vertex. In 6 subjects whole-brain magnetoencephalography (MEG) was further acquired following pharyngeal stimulation. Results: TMS evoked pharyngeal motor evoked potentials were facilitated by the pharyngeal stimulus at ISI between 50 and 80 ms (Δ mean increase: 47±6%, P<0.05). This correlated with the peak latency of the P1 component of the PSEP (mean 79.6±8.5 ms). MEG confirmed that the equivalent P1 peak activities were localised to caudolateral sensory and motor cortices (BA 4, 1, 2). Conclusions: Facilitation of the cortico-bulbar pathway to pharyngeal stimulation relates to coincident afferent input to sensorimotor cortex. Significance: These findings have mechanistic importance on how pharyngeal stimulation may increase motor excitability and provide guidance on temporal windows for future manipulations of swallowing motor cortex. © 2004 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Assessing interactions of linear and nonlinear neuronal sources using MEG beamformers:a proof of concept

Objective: This study aimed to explore methods of assessing interactions between neuronal sources using MEG beamformers. However, beamformer methodology is based on the assumption of no linear long-term source interdependencies [VanVeen BD, vanDrongelen W, Yuchtman M, Suzuki A. Localization of brain electrical activity via linearly constrained minimum variance spatial filtering. IEEE Trans Biomed Eng 1997;44:867-80; Robinson SE, Vrba J. Functional neuroimaging by synthetic aperture magnetometry (SAM). In: Recent advances in Biomagnetism. Sendai: Tohoku University Press; 1999. p. 302-5]. Although such long-term correlations are not efficient and should not be anticipated in a healthy brain [Friston KJ. The labile brain. I. Neuronal transients and nonlinear coupling. Philos Trans R Soc Lond B Biol Sci 2000;355:215-36], transient correlations seem to underlie functional cortical coordination [Singer W. Neuronal synchrony: a versatile code for the definition of relations? Neuron 1999;49-65; Rodriguez E, George N, Lachaux J, Martinerie J, Renault B, Varela F. Perception's shadow: long-distance synchronization of human brain activity. Nature 1999;397:430-3; Bressler SL, Kelso J. Cortical coordination dynamics and cognition. Trends Cogn Sci 2001;5:26-36]. Methods: Two periodic sources were simulated and the effects of transient source correlation on the spatial and temporal performance of the MEG beamformer were examined. Subsequently, the interdependencies of the reconstructed sources were investigated using coherence and phase synchronization analysis based on Mutual Information. Finally, two interacting nonlinear systems served as neuronal sources and their phase interdependencies were studied under realistic measurement conditions. Results: Both the spatial and the temporal beamformer source reconstructions were accurate as long as the transient source correlation did not exceed 30-40 percent of the duration of beamformer analysis. In addition, the interdependencies of periodic sources were preserved by the beamformer and phase synchronization of interacting nonlinear sources could be detected. Conclusions: MEG beamformer methods in conjunction with analysis of source interdependencies could provide accurate spatial and temporal descriptions of interactions between linear and nonlinear neuronal sources. Significance: The proposed methods can be used for the study of interactions between neuronal sources. © 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The French Confederation Generale du Travail and the International Secretariat of National Trade Union Centres (1900-1914):French syndicalist attitudes towards internationalism and the International Labour Movement

This thesis examines relations between the French Confederation Generale du Travail (CGT) and the labour movements of other countries in the years leading up to the First World War. The aim of the study is to examine the CGT's policy of internationalism in practice, both in relations with other labour movements and in its membership of the International Secretariat of National Trade Union Centres (between 1900 and 1914). In particular, the relationship between the French and German labour movements is explored in the light of the events of August 1914. This study shows that the relationship was a reflection of the respective positions of the French and German labour movements in the international movement. It also subjects to close scrutiny the assumption, widely made before 1914, that workers had more in common with each other than with the ruling classes of their own country, by analysing the extent of, and the reasons for internationalism and international cooperation in the labour movement. As a study of the International Secretariat of National Trade Union Centres, an organisation about which very little has previously been written, this thesis complements existing work on the international labour movement prior to 1914. It also provides new insights into the French CGT by concentrating on the fundamental areas of internationalism and opposition to war, and offers fresh contributions to the continuing debate on the international labour movement and its response to the outbreak of war.

The changing roles of accountants in industry.

Both accountants and their professional associations have come under pressure in recent years to move with a changing environment. A research project was established therefore in order to study the present roles of accountants in industry, to consider how such roles have evolved, and to consider ways in which these roles might change in the future. Apart from these specific objectives, the thesis also attempts to come to terms with some of the major philosophical and theoretical challenges that face sociology. Given these broad aims, and given a limited amount of previous research, the approach was to derive tentative classifications and propositions from empirical investigation, rather than to test preconceived hypotheses. Data was obtained primarily from ninety-nine structured interviews with both accountants and other managers from twelve industrial enterprises. Aside from studying specifically the changing roles of accountants in industry, the following areas were investigated: the historical development of industrial organisations, accounting systems, and the professional accounting bodies; the process of occupational entry, socialisation, and career paths of accountants; and the current education, training, and career development of, and labour market for, accountants in industry. Despite variations according to accountants' positions, the sample's work characteristics and orientations were found to be similar to those of managers from other areas. In fact most accountants were more concerned with 'getting on' than committed to a career in accounting or to any particular professional association or employing organisation. While there was a move towards a more general business involvement for the majority of the sample, there was also in some cases an increasing demand for specialist accounting skills. In conclusion, although an eventual technological substitution for the work of accountants in industry is thought to be unlikely, their work is becoming more liable to evaluation and intervention form those outside their occupational group.

Critical factors influencing structure, strategy and international competitiveness of Greek businesses

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Editorial:welcome to the LRN2004 annual conference special issue of the International journal of logistics: research and applications

It is a great pleasure to be Guest Editor for this issue – I hope that the papers which are included will be stimulating and support you in your ongoing research activities. A number of guiding principles were adopted in selecting the papers for inclusion in this issue. Firstly, the papers cover a wide range of logistics and supply chain management (SCM) topics. This is a reflection of the evolution of the field in recent years. In terms of the “buy-make-store-move-sell” model of SCM all the main constituent areas are addressed. Secondly, it is important that the conference issue of this Journal reflects the emphasis and content of the conference itself. I have tried to achieve this in terms of the papers included. One interesting point to note is that outsourcing is a theme which is a major issue in a number of papers. This reflects the increasing importance of this issue to organisations of all kinds and sizes. Economic globalisation and the trend towards vertical disintegration of supply chain architectures have sharpened the focus on outsourcing as a key element of supply chain strategy. The need to move beyond the notion that sourcing of certain activities can be some kind of panacea in evident from the relevant contributions. Thirdly, the LRN Annual Conference has become a more international event in recent years...the number of delegates and papers presented from outside the UK has continued to grow. The papers collected in this issue reflect this internationalization. Two papers are worthy of particular comment from an LRN perspective. The contribution by Jaafar and Rafiq has been developed from the submission which won the best paper prize at the LRN 2004 event. The paper by Pettit and Beresford is based on research which was supported by LRN seed corn funding. It was developed form the final report on this work submitted to CITL (UK) via the LRN. The seed corn funding is an important mechanism whereby the LRN supports research in innovative aspects of logistics in UK universities. In many ways, the LRN2004 event in Dublin seems like a long time ago. From my point of view it was one of the most professionally rewarding activities in which I have been involved in my career. It was a time to meet old friends and new and to keep abreast of the multitude of interesting projects being undertaken in over 20 countries. There are too many people to thank for the smooth running of the event. However, my colleague John Mee does warrant a special mention. His logistical skills were seriously put to the test in the weeks and months leading up to September 9th. 2004. I want to acknowledge his particular contribution to the success of the event. Since then we have had the 2005 event at the University of Plymouth. This was again a great opportunity to network with colleagues and many congratulations are due to John Dinwoodie and his team. We now look forward to LRN 2006 in Newcastle...form my part I hope and trust that this issue provides some useful perspectives and insights into the range of topics addressed.

Some historical extracts relevant to the discovery and application of the diffraction of X-rays by crystals to contribute to the centennial celebration and the International Year of Crystallography

Illustrative extracts from the writings of Paul P. Ewald and of Max von Laue are presented. The latter in turn contains extensive text contributions from William Lawrence Bragg. These selections we have chosen so as to indicate the nature of the discovery of X-ray diffraction from crystals (experiments undertaken by Friedrich, Knipping and von Laue) and its early and prompt application in crystal structure analyses (by William Henry Bragg and William Lawrence Bragg). The platform for these discoveries was provided by a macroscopic physics problem dealt with by Ewald in his doctoral thesis with Arnold Sommerfeld in the Munich Physics Department, which is also where von Laue was based. W.L. Bragg was a student in Cambridge who used Trinity College Cambridge as his address on his early papers; experimental work was done by him in the Cavendish Laboratory, Cambridge, and also with his father, W.H. Bragg, in the Leeds University Physics Department. Of further historical interest is the award of an Honorary DSc (Doctor of Science) degree in 1936 to Max von Laue by the University of Manchester, UK, while William Lawrence Bragg was Langworthy Professor of Physics there. © 2012 Copyright Taylor and Francis Group, LLC.

Special issue on '6th CIRP-Sponsored International Conference of Digital Enterprise Technology (DET2009) - Enterprise Informatics'

Editorial

Modelling the E-business requirements of manufacturing organisations

This paper describes a model designed to recommend solutions to an organisation's e-business needs. It is designed to produce objective results based on perceived characteristics, unbiased by prejudice on the part of the person using the model. The model also includes a way of encapsulating the potential management concerns that may change for good or ill the likely relevance and probability of success of such solutions. The model has been tested on 13 case studies in small, medium and large organizations. © IFAC.

The factors affecting the international judgement of the Forint and Zloty in the light of the financial crisis of year 2008

The financial crisis of 2007-2009 has shaken both money and capital markets. Its consequences have not even left European markets untouched and divided spirits in the financial world. In some countries efforts by the monetary policy to protect the national currency throughout the crisis seemed to be ineffective. In the present paper we are investigating the effect of the most important macroeconomic and economic policy factors on the exchange rate of the forint and zloty in the last decade. For an analysis of exchange rates we are relying on some preceding research results based on equilibrium exchange rate theories.

Tax incentives applied against externalities: International examples of fat tax and carbon tax

This study assesses the Pigou taxes introduced as a response to negative externalities in practice. The authors analyze the international practice and effectiveness of taxation on food products harmful to health and on carbon emissions harmful to the environment and, in relation to these two types of taxes, the focus is on the opportunities and the factors reducing efficiency.