Are you willing to be made nothing? Is Commonwealth reform possible?

A new round of Commonwealth reform proposals commenced at the Commonwealth Heads of Government Meeting of 2009. An ensuing report, titled A Commonwealth of the people: time for urgent reform, contained a long list of proposals that eventually resulted in 2013 in the adoption of the Commonwealth Charter. Many classic international organizations are in need of reform, but this is, of course, challenging. This new Commonwealth reform process will not lead to satisfying changes and will not make it a more relevant actor in global governance. The year 2015 marks the Commonwealth Secretariat’s first half-century. We take this symbolic marker to push for a forward-looking exercise, arguing that because the true nature of the Commonwealth is often misunderstood, a better understanding of the organization is essential before embarking on any successful change-management project. In the article we identify four different kinds of Commonwealth: three of a ‘formal’ nature (the official, bureaucratic and the people’s Commonwealth) and a fourth ‘informal’ one (Commonwealth Plus). By describing the potential of these four different kinds of Commonwealth, we can anticipate better the challenges with which the Commonwealth network is faced, both internal (including its mandate, its British imperial past and dominance, the organization’s leadership and its membership) and external (other international organizations, other Commonwealths, rivalry with regional organizations and the rise of global policy networks). Consequently, this should lead to a better and more sustainable debate about the Commonwealth’s future role in global governance

Coherent and Incoherent Vortex Flow States in Crossed Channels

We examine vortex flow states in periodic square pinning arrays with one row and one column of pinning sites removed to create an easy flow crossed channel geometry. When a drive is simultaneously applied along both major symmetry axes of the pinning array such that vortices move in both channels, a series of coherent flow states develop in the channel intersection at rational ratios of the drive components in each symmetry direction when the vortices can cross the intersection without local collisions. The coherent flow states are correlated with a series of anomalies in the velocity force curves, and in some cases can produce negative differential conductivity. The same general behavior could also be realized in other systems including colloids, particle traffic in microfluidic devices, or Wigner crystals in crossed one-dimensional channels.Comment: 5 pages, 4 postscript figure

Confinement and Quantization Effects in Mesoscopic Superconducting Structures

We have studied quantization and confinement effects in nanostructured superconductors. Three different types of nanostructured samples were investigated: individual structures (line, loop, dot), 1-dimensional (1D) clusters of loops and 2D clusters of antidots, and finally large lattices of antidots. Hereby, a crossover from individual elementary "plaquettes", via clusters, to huge arrays of these elements, is realized. The main idea of our study was to vary the boundary conditions for confinement of the superconducting condensate by taking samples of different topology and, through that, modifying the lowest Landau level E_LLL(H). Since the critical temperature versus applied magnetic field T_c(H) is, in fact, E_LLL(H) measured in temperature units, it is varied as well when the sample topology is changed through nanostructuring. We demonstrate that in all studied nanostructured superconductors the shape of the T_c(H) phase boundary is determined by the confinement topology in a unique way.Comment: 28 pages, 19 EPS figures, uses LaTeX's aipproc.sty, contribution to Euroschool on "Superconductivity in Networks and Mesoscopic Systems", held in Siena, Italy (8-20 september 1997

Congolese rhizospheric soils as a rich source of new plant growth-promoting endophytic Piriformospora isolates

In the last decade, there has been an increasing focus on the implementation of plant growth-promoting (PGP) organisms as a sustainable option to compensate for poor soil fertility conditions in developing countries. Trap systems were used in an effort to isolate PGP fungi from rhizospheric soil samples collected in the region around Kisangani in the Democratic Republic of Congo. With sudangrass as a host, a highly conducive environment was created for sebacinalean chlamydospore formation inside the plant roots resulting in a collection of 51 axenically cultured isolates of the elusive genus Piriformospora (recently transferred to the genus Serendipita). Based on morphological data, ISSR fingerprinting profiles and marker gene sequences, we propose that these isolates together with Piriformospora williamsii constitute a species complex designated Piriformospora (= Serendipita) 'williamsii.' A selection of isolates strongly promoted plant growth of in vitro inoculated Arabidopsis seedlings, which was evidenced by an increase in shoot fresh weight and a strong stimulation of lateral root formation. This isolate collection provides unprecedented opportunities for fundamental as well as translational research on the Serendipitaceae, a family of fungal endophytes in full expansion

London equation studies of thin-film superconductors with a triangular antidot lattice

We report on a study of vortex pinning in nanoscale antidot defect arrays in the context of the London Theory. Using a wire network model, we discretize the array with a fine mesh, thereby providing a detailed treatment of pinning phenomena. The use of a fine grid has enabled us to examine both circular and elongated defects, patterned in the form of a rhombus. The latter display pinning characteristics superior to circular defects constructed with the similar area. We calculate pinning potentials for defects containing zero and single quanta, and we obtain a pinning phase diagram for the second matching field, $H = 2 \Phi_{o}$.Comment: 10 pages and 14 figure

Continuous Melting of a "Partially Pinned" Two-Dimensional Vortex Lattice in a Square Array of Pinning Centers

The structure and equilibrium properties of a two-dimensional system of superconducting vortices in a periodic pinning potential with square symmetry are studied numerically. For a range of the strength of the pinning potential, the low-temperature crystalline state exhibits only one of the two basic periodicities (in the $x$- and $y$-directions) of the pinning potential. This ``partially pinned'' solid undergoes a continuous melting transition to a weakly modulated liquid as the temperature is increased. A spin model, constructed using symmetry arguments, is shown to reproduce the critical behavior at this transition.Comment: 5 pages, 4 figure

Commensurate and Incommensurate Vortex States in Superconductors with Periodic Pinning Arrays

As a function of applied field, we find a rich variety of ordered and partially-ordered vortex lattice configurations in systems with square or triangular arrays of pinning sites. We present formulas that predict the matching fields at which commensurate vortex configurations occur and the vortex lattice orientation with respect to the pinning lattice. Our results are in excellent agreement with recent imaging experiments on square pinning arrays [K. Harada et al., Science 274, 1167 (1996)].Comment: 9 pages, 3 figures. Accepted to Physical Review

Acting Out Ideas: Performative Citizenship in the Black Consciousness Movement

This paper introduces the concept of ‘performative citizenship’ to account for the manner in which the Black Consciousness Movement (BCM), and in particular its charismatic leader Steve Biko, transformed a collection of relatively abstract philosophical ideas into concrete political practice. We outline how the BCM challenged the psychological internalisation of white supremacy and asserted citizenship claims through a variety of performative techniques, many of which explicitly and implicitly reiterated earlier rights-based claims both in South Africa and abroad. We show how this took place within a remarkably restrictive context, which on the one hand constrained performances, but on the other augmented their dramatic efficacy. The paper makes an argument about the performance of counter-power, showing how whilst the apartheid complex retained its command over economic, military, and political power, it struggled to control the social drama that was unfolding on the cultural plane, therefore losing its grip on one key element of ideological power. Finally, the paper also makes a methodological contribution to reception studies by showing how researching the reception of ideas exclusively through the spoken or written word neglects other modes through which ideas might find expression, especially in contexts of pervasive censorship and political repression.The research leading to these results has received funding from a Leverhulme Trust Early Career Fellowship, the Isaac Newton Trust, and the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no319974 (INTERCO-SSH)

Characterization of immune response to neurofilament light in experimental autoimmune encephalomyelitis

PMCID: PMC3856490This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.PMCID: PMC385649