Semantic cognition: a re-examination of the recurrent network "hub" model

This paper explores a model of “semantic cognition” first described in Rogers et al. (2004). This model was shown to reproduce the behaviour of neurological patients who perform poorly on a variety of tests of semantic knowledge; thus purporting to provide a comprehensive explanation for semantic deficits as found in patients with semantic dementia and, as extended in Lambon Ralph, Lowe, and Rogers (2007), individuals with herpes simplex virus encephalitis. Therefore, not only does the model emulate these semantic impairments, it also underpins a theoretical account of such memory disturbances. We report preliminary results arising from an attempted reimplementation of the Rogers et al. model. Specifically, while we were able to successfully reimplement the fully-functioning model and recreate “normal” behaviour, our attempts to replicate the behaviour of semantically impaired patients by lesioning the model were mixed. Our results suggest that while semantic impairments reminiscent of patients may arise when the Rogers et al. model is lesioned, such impairments are not a necessary consequence of the model. We discuss the implications of these apparently negative results for the Rogers et al. account of semantic cognition

Industrial Relations in Greenfield Sites

There is a popular stereotype that at greenfield sites managers practice, and sustain over time new forms of human resource management and that in doing so they obtain highly positive performance outcomes. A persisting theme in this stereotype is that greenfield sites are characterised by a highly collaborative form of employee relations and that they are largely strike and conflict free. The aim of this paper is to test the stereotype by reviewing what is known about the subject. Existing research on greenfield sites is places within a broad conceptual framework, key issues are highlighted and gaps in our knowledge identified. The discussion in foreign-owned firms; how well greenfield sites cope with the ageing process; and the industrial relations and human resource outcomes obtained in greenfield sites. The review finds that most research ignores the last two issues. At present it is impossible to conclude with confidence that IR/HR practices adopted in these firms are any more effective than traditional systems. There is also little or no evidence about how greenfield site practices adapt over time. The review provides the point of departures for research being undertaken at the LSE's Centre for Economic Performance; the research agenda is briefly discussed.

The Long-Run Performance of Hostile Takeovers: UK Evidence

This paper examines the long-run pre- and post-takeover performance of hostile takeovers in the U.K. from 1985-96. Prior to takeover, targets in hostile takeovers experience a significant deterioration in profit returns, and significantly negative share returns. However, there is little evidence that profit levels are lower than those of non- merging firms. Bidders in hostile takeovers are not superior performers in terms of profit levels, although share returns are significantly high prior to takeover. However, in the post-takeover period hostile takeovers show significant improvements in profit returns, which are associated with significant asset disposals. In contrast, friendly takeovers do not improve profit returns and result in significantly negative long-run share returns. We find no evidence of an inverse relation between the performance improvement in hostile takeovers and the pre-takeover performance of the target. We interpret the results to indicate that although hostile takeovers improve performance, there is little evidence that they play an important role in reversing the nonvalue maximizing behaviour of target companies.Hostile takeovers; friendly takeovers; disciplinary hypothesis; pre-takeover performance; post-takeover performance

Oviposition strategies of aphidophagous syrphidae

Imperial Users onl

Managerial Discretion and Takeover Performance

We investigate the relation between long run takeover performance and board share ownership in the acquiring company for a sample of 142 UK takeovers completed between 1985-95. We find evidence of a non-linear relationship both between board ownership and takeover profitability, and between board ownership and post-takeover share returns. We cast the analysis in a simultaneous equations framework using non- linear two-stage least squares, and find that our results are robust to this alternative specification. The results are therefore consistent with a managerial alignment / entrenchment trade-off.Corporate takeovers; board ownership; profitability; long run share returns

Leading-edge slat optimization for maximum airfoil lift

A numerical procedure for determining the position (horizontal location, vertical location, and deflection) of a leading edge slat that maximizes the lift of multielement airfoils is presented. The structure of the flow field is calculated by iteratively coupling potential flow and boundary layer analysis. This aerodynamic calculation is combined with a constrained function minimization analysis to determine the position of a leading edge slat so that the suction peak on the nose of the main airfoil is minized. The slat position is constrained by the numerical procedure to ensure an attached boundary layer on the upper surface of the slat and to ensure negligible interaction between the slat wake and the boundary layer on the upper surface of the main airfoil. The highest angle attack at which this optimized slat position can maintain attached flow on the main airfoil defines the optimum slat position for maximum lift. The design method is demonstrated for an airfoil equipped with a leading-edge slat and a trailing edge, single-slotted flap. The theoretical results are compared with experimental data, obtained in the Ames 40 by 80 Foot Wind Tunnel, to verify experimentally the predicted slat position for maximum lift. The experimentally optimized slat position is in good agreement with the theoretical prediction, indicating that the theoretical procedure is a feasible design method

Exploring Roman Caerleon: new excavations at the legionary fortress of Isca

The Roman legionary fortress at Caerleon in south Wales, has been subject to archaeological investigation for more than 150 years, including the well-known amphitheatre excavations conducted by Mortimer and Tessa Wheeler in the 1920s. This retrospective link with the Institute of Archaeology has now been reinforced by a new project, organized jointly by UCL and Cardiff University, starting in 2007. Here the Directors of the project discuss their aims and the results of the first two seasons of work