Some Observations on the Agrarian Question in the Era of Economic Liberalisation in Sub-Saharan Africa: Which Way Forward?

This paper contributes to the debate on the way forward in sub-­‐Saharan Africa with respect to the agrarian question in emerging markets under economic liberalisation. The point of departure is that since the peasantry is a temporary category which can be transformed into other social groups that can earn their living from incomes raised outside agriculture (such as from wage employment in mines, manufacturing industries, and the service sectors), not every rural dweller should be or is a farmer. Improved methods of cultivation especially with mechanisation, agricultural extension, entrepreneurship, and skills training and empowerment of women and youth; secure land tenure for collateral; infrastructure development to link farmers to markets; and finance can help a small proportion of the rural populations of Africa to graduate into commercial farmers who could produce enough food to feed the continent. The surplus population could be absorbed in wage employment in agro-­‐processing industries, and in other value adding industries outside agriculture such as mineral processing, if Africa experiences industrial transformation. This is largely the experience of industrialised countries that have experienced such transformation in the last 50 years or so, the same period African countries have enjoyed political independence, but have lagged behind with respect to resolving the agrarian question

Enhanced thermal performance of garments embedded with encapsulated phase change material

The thermal storage and insulation properties of garments enhanced with phase change material (PCM) will be investigated using a finite difference procedure. A diver dry suit embedded with micro-encapsulated PCM will be shown to enhance thermal protection under extreme temperature conditions. Under conditions of high body heat production a garment embedded with Macro-encapsulated PCM is shown to absorb excess heat while maintaining a relatively constant temperature

Group inquiry to aid organisational learning in enterprises

This paper describes a method for surfacing and exploring ‘situated knowledge’ in medium-sized organisations, with employee groups utilising a ‘low impact’ form of group support system (GSS), based on wireless handsets. Some results of piloting this method are summarised and one intervention is presented in detail. The method encouraged organisational members to give voice to the emotions and politics of leadership and learning in organisations, and helped to articulate how situated knowledge was ignored, as well as utilised. The method is practical, and may be used by organisations for themselves to aid the development of group as well as individual reflection, to stimulate the consideration of change

Variability of the Centimeter-Submillimeter Spectrum and Polarization of 3C 273 during Outburst

Original article can be found at: http://www.journals.uchicago.edu/ApJ/--Copyright University of Chicago Press/ AASCentimeter to submillimeter total flux and polarization monitoring data are used to investigate the nature of a prominent flare in the quasar 3C 273 during 1995/6. After removal of the quiescent level, the resulting “flare spectra" are well fitted by a simple homogeneous synchrotron source model, which in turn allows the movement of the self-absorption turnover to be tracked during the flare. Both the flare amplitude/time delay relationship and the overall spectral evolution are qualitatively consistent with existing models. The early evolution of the spectrum is best determined and is shown to be in excellent agreement with the Compton stage of the Marscher & Gear shock model. However, the polarization behavior during the flare is different at millimeter and centimeter wavelengths and the observations are difficult to reconcile with a simple transverse shock. They are, however, consistent with a conical shock for which the observed polarization properties vary with distance along the jet. Such variations may be caused, for example, by a change in cone angle owing to disruption caused by the growing component of the magnetic field parallel to the jet axis or by a moderate change in viewing angle.Peer reviewe

Active Brownian particles with velocity-alignment and active fluctuations

We consider a model of active Brownian particles with velocity-alignment in two spatial dimensions with passive and active fluctuations. Hereby, active fluctuations refers to purely non-equilibrium stochastic forces correlated with the heading of an individual active particle. In the simplest case studied here, they are assumed as independent stochastic forces parallel (speed noise) and perpendicular (angular noise) to the velocity of the particle. On the other hand, passive fluctuations are defined by a noise vector independent of the direction of motion of a particle, and may account for example for thermal fluctuations. We derive a macroscopic description of the active Brownian particle gas with velocity-alignment interaction. Hereby, we start from the individual based description in terms of stochastic differential equations (Langevin equations) and derive equations of motion for the coarse grained kinetic variables (density, velocity and temperature) via a moment expansion of the corresponding probability density function. We focus here in particular on the different impact of active and passive fluctuations on the onset of collective motion and show how active fluctuations in the active Brownian dynamics can change the phase-transition behaviour of the system. In particular, we show that active angular fluctuation lead to an earlier breakdown of collective motion and to emergence of a new bistable regime in the mean-field case.Comment: 5 figures, 22 pages, submitted to New Journal of Physic