Mergers

Using small matched samples of companies which are, and are not, highly involved in acquisition in the period 1986-90, an investigation is mounted to ascertain whether "acquisitiveness" has any impact upon the remuneration of the top directors over and above what one would expect because of the growth in "size". The evidence suggests it does, if returns to share options are included in the measure of remuneration.

Dynamics of vortex tangle without mutual friction in superfluid 4^4He

A recent experiment has shown that a tangle of quantized vortices in superfluid $^4$He decayed even at mK temperatures where the normal fluid was negligible and no mutual friction worked. Motivated by this experiment, this work studies numerically the dynamics of the vortex tangle without the mutual friction, thus showing that a self-similar cascade process, whereby large vortex loops break up to smaller ones, proceeds in the vortex tangle and is closely related with its free decay. This cascade process which may be covered with the mutual friction at higher temperatures is just the one at zero temperature Feynman proposed long ago. The full Biot-Savart calculation is made for dilute vortices, while the localized induction approximation is used for a dense tangle. The former finds the elementary scenario: the reconnection of the vortices excites vortex waves along them and makes them kinked, which could be suppressed if the mutual friction worked. The kinked parts reconnect with the vortex they belong to, dividing into small loops. The latter simulation under the localized induction approximation shows that such cascade process actually proceeds self-similarly in a dense tangle and continues to make small vortices. Considering that the vortices of the interatomic size no longer keep the picture of vortex, the cascade process leads to the decay of the vortex line density. The presence of the cascade process is supported also by investigating the classification of the reconnection type and the size distribution of vortices. The decay of the vortex line density is consistent with the solution of the Vinen's equation which was originally derived on the basis of the idea of homogeneous turbulence with the cascade process. The obtained result is compared with the recent Vinen's theory.Comment: 16 pages, 16 figures, submitted to PR

Can Cash Transfer Programmes Have 'Transformative' Effects?

Cash transfers (CTs), for all their evident success in relieving poverty, have been criticised for failing to incorporate transformative elements into their programme design. In recent years changes have been introduced into the design of CT programmes that go some way towards addressing this concern. This article critically engages the meaning of transformative social protection and introduces a collection of papers that examine whether and under what conditions cash transfers can be ‘transformative’. Among the issues addressed are whether CTs can be catalysts leading to positive changes, material, subjective and relational in the lives of poor people; what are the social effects of CTs for beneficiaries, their households and communities; and can they foster horizontal relationships within communities and vertical relationship with the state through developing forms of social accountability and citizenship engagement

Evaporation of a packet of quantized vorticity

A recent experiment has confirmed the existence of quantized turbulence in superfluid He3-B and suggested that turbulence is inhomogenous and spreads away from the region around the vibrating wire where it is created. To interpret the experiment we study numerically the diffusion of a packet of quantized vortex lines which is initially confined inside a small region of space. We find that reconnections fragment the packet into a gas of small vortex loops which fly away. We determine the time scale of the process and find that it is in order of magnitude agreement with the experiment.Comment: figure 1a,b,c and d, figure2, figure

Evaluation of the CNS and cardiovascular effects of prolonged exposure to bromotrifluromethane (CBrF3)

The proposed use of bromotrifluoromethane (CBrF3) as a fire extinguishant in aircraft, spacecraft and submarines has stimulated increasing interest and research in the toxicological properties of this compound. In a spacecraft, because of its unique recirculating life support system, the introduction of CBrF3 by leakage or intentional discharge, will result in continuous exposure of crewman to low concentrations of this compound for periods of up to 7 days, or possibly even longer. The effects of low concentrations of CBrF3, under continuous exposure conditions, on the CNS and cardiovascular systems of animals to enable an assessment of these risks were investigated

Fluctuating Elastic Rings: Statics and Dynamics

We study the effects of thermal fluctuations on elastic rings. Analytical expressions are derived for correlation functions of Euler angles, mean square distance between points on the ring contour, radius of gyration, and probability distribution of writhe fluctuations. Since fluctuation amplitudes diverge in the limit of vanishing twist rigidity, twist elasticity is essential for the description of fluctuating rings. We find a crossover from a small scale regime in which the filament behaves as a straight rod, to a large scale regime in which spontaneous curvature is important and twist rigidity affects the spatial configurations of the ring. The fluctuation-dissipation relation between correlation functions of Euler angles and response functions, is used to study the deformation of the ring by external forces. The effects of inertia and dissipation on the relaxation of temporal correlations of writhe fluctuations, are analyzed using Langevin dynamics.Comment: 43 pages, 9 Figure

Development and evaluation of a photometric fibre-optic sensor for monitoring abdominal organ photoplethysmographs and blood oxygen saturation

A two wavelength photometric fibre-optic reflectance sensor was developed for assessing abdominal organ perfusion. In vitro tests showed that reliable photoplethysmographic (PPG) signals and blood oxygen saturation (SpO2) values were recorded when the separation between emitting and receiving fibres was at 3mm and the emitting current was between 20mA-40mA. In a clinical study, good quality PPG signals were obtained from the small and large bowel of a patient undergoing laparotomy. Abdominal organ SpO2 were in good agreement with those obtained from a commercial device. These observations suggest that the fibre-optic sensor may be suitable for monitoring abdominal organ perfusion

Preliminary assessment of abdominal organ perfusion utilizing a fiber optic photoplethysmographic sensor

In an attempt to overcome the limitations of current techniques for monitoring abdominal organ perfusion, a prototype reflectance fiber optic photoplethysmographic (PPG) sensor and processing system was evaluated on seventeen anaesthetized patients undergoing laparotomy. Good quality PPG signals were obtained from the large bowel, small bowel, liver and stomach. Simultaneous PPG signals from the finger were also obtained for comparison purposes using an identical fiber optic sensor. Analysis of the mean ac and dc PPG amplitudes of all acquired signals indicated larger amplitudes for those signals obtained from abdominal organs than those obtained from the finger. Mean estimated blood oxygen saturation (SpO2) values from all abdominal sites showed good agreement with those obtained from the finger using both the finger fiber optic sensor and a commercial finger pulse oximeter. Furthermore, a Bland and Altman between-method-differences analysis on the estimated SpO2 data suggests that a fiber optic abdominal sensor may be a suitable method for the evaluation of abdominal organ perfusion

A New Fibre Optic Pulse Oximeter Probe for Monitoring Splanchnic Organ Arterial Blood Oxygen Saturation

a new continuous method of monitoring splanchnic organ oxygen saturation (SpO2) would make the early detection of inadequate tissue oxygenation feasible, reducing the risk of hypoperfusion, severe ischaemia, and, ultimately, death. In an attempt to provide such a device, a new fiber optic based reflectance pulse oximeter probe and processing system were developed followed by an in vivo evaluation of the technology on seventeen patients undergoing elective laparotomy. Photoplethysmographic (PPG) signals of good quality were obtained from the small bowel, large bowel, liver and stomach. Simultaneous peripheral PPG signals from the finger were also obtained for comparison purposes. Analysis of the amplitudes of all acquired PPG signals indicated much larger amplitudes for those signals obtained from splanchnic organs than those obtained from the periphery. Estimated SpO2 values for splanchnic organs showed good agreement with those obtained from the peripheral fibre optic probe and those obtained from a commercial device. These preliminary results suggest that a miniaturized ‘indwelling’ fibre optic sensor may be a suitable method for pre-operative and post-operative evaluation of splanchnic organ SpO2 and their health