Beyond Fashoda: Anglo-French security cooperation in Africa since St-Malo

Traditionally divided on security matters, France and Britain broke new ground when they signed the 1998 Saint-Malo agreement, promising to collaborate on defence and security, and pledging to cooperate bilaterally and in a ‘bi-multi’ fashion on Africa. This Anglo-French collaboration is the focus of this article, which begins by setting out the lack of UK–French security cooperation in Africa from the colonial to the early post-Cold War era. It then shows how there has been a degree of institutionalization of Anglo-French relations, alongside greater cooperation in terms of ESDP missions and the training of African peacekeepers. Next, this study explains the recent evolution of UK–French security relations in terms of neo-classical realist theory. Finally, it assesses the likelihood of closer Anglo-French security collaboration in the future

Multiple traffic signal control using a genetic algorithm

Optimising traffic signal timings for a multiple-junction road network is a difficult but important problem. The essential difficulty of this problem is that the traffic signals need to coordinate their behaviours to achieve the common goal of optimising overall network delay. This paper discusses a novel approach towards the generation of optimal signalling strategies, based on the use of a genetic algorithm (GA). This GA optimises the set of signal timings for all junctions in network. The different efficient red and green times for all the signals are determined by genetic algorithm as well as the offset time for each junction. Previous attempts to do this rely on a fixed cycle time, whereas the algorithm described here attempts to optimise cycle time for each junction as well as proportion of green times. The fitness function is a measure of the overall delay of the network. The resulting optimised signalling strategies were compared against a well-known civil engineering technique, and conclusions drawn

Comparative Venture Capital Governance. Private versus Labour Sponsored Venture Capital Funds

Private independent limited partnership venture capital funds receive capital from institutional investors, without tax incentives. Limited partnership investment activities are governed by restrictive covenants that are determined by negotiated contract between the fund managers (general partners) and the institutional investors (limited partners). By contrast, Canadian Labour Sponsored Venture Capital Corporations (LSVCCs) receive capital only from individual investors who receive tax breaks on capital contributions of up to CAN$5,000. LSVCC investment activities are governed by statutory restrictions. This chapter contrasts the governance of LSVCCs to limited partnerships. We also summarize Canadian evidence on the impact of LSVCC governance and tax incentives: (1) on the distribution of venture capital funding between private and LSVCC funds; (2) on the unusually large overhang of uninvested capital in the Canadian venture capital industry; (3) the portfolio size (i.e. number of investee firms per fund) of private funds versus LSVCCs; and (4) the performance of LSVCCs relative to other types of venture capital organiziations and other comparable investments for individual investors.venture capital, Canada, tax, government, crowding out, portfolio size, governance

Plasmonic gold nanodiscs using piezoelectric substrate birefringence for liquid sensing

This article presents the simulation, fabrication, and experimental characterization of a surface plasmonic resonance (SPR) sensor integrated with an acoustic sensing compatible substrate. The SPR sensor is designed to work in the visible region with gold nanodisc arrays fabricated on LiNbO3, which is both piezoelectric and birefringent. A linear relationship between resonance wavelength and varying liquid refractive indices were observed in experiments, and a sensitivity of 165 nm/refractive index unit was obtained. Polarization effects of the birefringent property of the Y-cut LiNbO3 substrate have been investigated, which can also be applied to X-cut LiNbO3. Our study demonstrates the feasibility of an SPR sensor device utilizing a birefringent substrate, which has acoustic wave compatibility and can pave the way toward much more robust and flexible biosensing device

Status of woodland caribou in Ontario: 1996

Over 20 000 woodland caribou were reported in Ontario during 1966, the highest figure ever published. Photographic counts of the Pen Islands herd, bordering Manitoba, have shown constant increases from 2300 in 1979 to 10 800 in 1994. Elsewhere in Ontario, estimates have been declining, from 13 000 in 1965 to 11 000 in 1989 to under 10 000 in 1996, a trend that may or may not be real because of differing survey methods. On the Hudson Bay Lowlands (excluding the Pen Islands caribou) 8600 were reported in 1965, 7200 in 1989, 5500 in 1996, an apparent decline. The transitional forest populations has remained stable. Estimated caribou numbers inhabiting the true boreal forest have dropped from nearly 4000 in 1965 to 2700 in 1996, but this decrease was not confirmed by careful within-district breakdowns of sub-populations by habitat types and may be an artifact of classification from districts to regions. The sharpest decrease was reported for the Central Region, north east of Lake Superior, where estimates dropped from 500 in 1965 to 475 in 1989 and to 68 in 1996. Individual caribou bands approach recognized minimum numbers for isolated populations, and even totals by sub-population remain low: over 1300 in commercial forests, about 500 in potentially commercial forests, and 8-900 in parks. Due to small numbers in widely dispersed band-locations, the potential for human disturbance affecting these forest dwelling caribou is substantial

Constraining the neutron star equation of state using quiescent low-mass X-ray binaries

Chandra or XMM-Newton observations of quiescent low-mass X-ray binaries can provide important constraints on the equation of state of neutron stars. The mass and radius of the neutron star can potentially be determined from fitting a neutron star atmosphere model to the observed X-ray spectrum. For a radius measurement it is of critical importance that the distance to the source is well constrained since the fractional uncertainty in the radius is at least as large as the fractional uncertainty in the distance. Uncertainties in modelling the neutron star atmosphere remain. At this stage it is not yet clear if the soft thermal component in the spectra of many quiescent X-ray binaries is variable on timescales too short to be accommodated by the cooling neutron star scenario. This can be tested with a long XMM-Newton observation of the neutron star X-ray transient CenX-4 in quiescence. With such an observation one can use the Reflection Grating Spectrometer spectrum to constrain the interstellar extinction to the source. This removes this parameter from the X-ray spectral fitting of the EPIC pn and MOS spectra and allows one to investigate whether the variability observed in the quiescent X-ray spectrum of this source is due to variations in the soft thermal spectral component or variations in the power law spectral component coupled with variations in N_H. This will test whether the soft thermal component can indeed be due to the hot thermal glow of the neutron star. Irrespective of the outcome of such a study, the observed cooling in quiescence in sources for which the crust is significantly out of thermal equilibrium with the core due to a prolonged outburst, such as KS 1731-260, seem excellent candidates for mass and radius determinations through modelling the observed X-rays with a neutron star atmosphere model.Comment: 7 pages, 3 figures, proceedings "40 years of pulsars" conferenc

On the reconstruction of a magnetosphere of pulsars nearby the light cylinder surface

A mechanism of generation of a toroidal component of large scale magnetic field, leading to the reconstruction of the pulsar magnetospheres is presented. In order to understand twisting of magnetic field lines, we investigate kinematics of a plasma stream rotating in the pulsar magnetosphere. Studying an exact set of equations describing the behavior of relativistic plasma flows, the increment of the curvature drift instability is derived, and estimated for $1s$ pulsars. It is shown that a new parametric mechanism is very efficient and can explain rotation energy pumping in the pulsar magnetospheres.Comment: 6 pages, 2 figure

Experimentally estimated dead space for GaAs and InP based planar Gunn diodes

The authors would like to thank the staff of the James Watt Nanofabrication Centre at the University of Glasgow for help in fabricating the devices which is reported in this paper. ‘Part of this work was supported by ESPRC through EP/H011862/ 1, and EP/H012966/1.Peer reviewedPublisher PD

Modeling Phase-resolved Observations of the Surfaces of Magnetic Neutron Stars

Recent observations by XMM-Newton detected rotational pulsations in the total brightness and spectrum of several neutron stars. To properly interpret the data, accurate modeling of neutron star emission is necessary. Detailed analysis of the shape and strength of the rotational variations allows a measurement of the surface composition and magnetic field, as well as constrains the nuclear equation of state. We discuss our models of the spectra and light curves of two of the most observed neutron stars, RX J1856.5-3754 and 1E 1207.4-5209, and discuss some implications of our results and the direction of future work.Comment: 5 pages, 6 figures; Proceedings of "40 Years of Pulsars", eds. C. Bassa, Z. Wang, A. Cumming, V. Kaspi, AIP, submitte

Latitudinal Shear Instabilities during Type I X-ray Bursts

Coherent oscillations have been observed during Type I X-ray bursts from 14 accreting neutron stars in low mass X-ray binaries, providing important information about their spin frequencies. However, the origin of the brightness asymmetry on the neutron star surface producing these oscillations is still not understood. We study the stability of a zonal shearing flow on the neutron star surface using a shallow water model. We show that differential rotation of >2% between pole and equator, with the equator spinning faster than the poles, is unstable to hydrodynamic shear instabilities. The unstable eigenmodes have properties well-matched to burst oscillations: low azimuthal wavenumber m, wave speeds 1 or 2% below the equatorial spin rate, and e-folding times close to a second. Instability is related to low frequency buoyantly driven r-modes that have a mode frequency within the range of rotation frequencies in the differentially rotating shell. We discuss the implications for burst oscillations. Growth of shear instabilities may explain the brightness asymmetry in the tail of X-ray bursts, although some fine tuning of the level of differential rotation and a spin frequency near 300 Hz are required in order for the fastest growing mode to have m=1. If shear instabilities are to operate during a burst, temperature contrasts of 30% across the star must be created during ignition and spreading of the flash.Comment: To appear in ApJ (12 pages, 11 figures