Degrees of permeability: confinement, power and resistance in Freetown's Central Prison

This article deconstructs a binary that has arisen between prisons as, on the one hand, ‘total institutions’ of exclusion and, on the other, ‘carceral continuums’ that incorporate marginalized urban livelihoods. The experiences of four inmates at Pademba Road, Freetown’s male prison – which accommodates inmates with sentences from one year to life – illustrate that prisons belong in neither camp. Instead, inmates’ unique responses to their imprisonment show that both a prison’s continuity and its exclusionary mechanism are situational and gendered as crime, social standing, capital and agency coalesce. Following Michel de Certeau’s examination of people’s reappropriations of culture in everyday life, this article analyses how inmates’ tactics to reinforce and bend prison walls work to either strengthen or undermine the carceral system’s strategies and influence the prison’s permeability. Inmates’ embodied experiences allow for a nuanced understanding of the inside/outside relationship of imprisonment and of the space between mobility and stasis, subjugation, embrace and resistance.</jats:p

Maximum Entropy Distributions Inferred from Option Portfolios on an Asset

We obtain the maximum entropy distribution for an asset from call and digital option prices. A rigorous mathematical proof of its existence and exponential form is given, which can also be applied to legitimise a formal derivation by Buchen and Kelly. We give a simple and robust algorithm for our method and compare our results to theirs. We present numerical results which show that our approach implies very realistic volatility surfaces even when calibrating only to at-the-money options. Finally, we apply our approach to options on the S&P 500 index.Comment: 23 pages, 5 figures, to appear in Finance and Stochastic

Pressure and isotope effect on the anisotropy of MgB2_{2}

We analyze the data for the pressure and boron isotope effect on the temperature dependence of the magnetization near $T_{c}$. Invoking the universal scaling relation for the magnetization at fixed magnetic field it is shown that the relative shift of $T_{c}$, induced by pressure or boron isotope exchange, mirrors essentially that of the anisotropy. This uncovers a novel generic property of anisotropic type II superconductors, inexistent in the isotropic case. For MgB$_{2}$ it implies that the renormalization of the Fermi surface topology due to pressure or isotope exchange is dominated by a mechanism controlling the anisotropy.Comment: 7 pages, 3 figure

The LION program Interim report

Review of development of LIO

A Climatology of the Tropospheric Thermal Stratification Using Saturation Potential Vorticity

The condition of convective neutrality is assessed in the troposphere by calculating the saturation potential vorticity P* from reanalysis data. Regions of the atmosphere in which saturation entropy is constant along isosurfaces of absolute angular momentum, a state indicative of slantwise-convective neutrality, have values of P* equal to zero. In a global reanalysis dataset spanning the years 1970–2004, tropospheric regions are identified in which P* is near zero, implying that vertical convection or slantwise convection may be important in determining the local thermal stratification. Convectively neutral air masses are common not only in the Tropics but also in higher latitudes, for example, over midlatitude continents in summer and in storm tracks over oceans in winter. Large-scale eddies appear to stabilize parts of the lower troposphere, particularly in winter

The Domestic Politics of International Cooperation: Germany and the European Debt Crisis

AbstractInternational cooperation can fail even though governments have no distributional conflicts or incentives to free-ride, face no informational or credibility problems, and even agree on the policies that need to be implemented. Germany's refusal to cooperate with the Eurogroup members on the Greek bailout in 2010 until the crisis threatened to derail the entire Eurozone is puzzling in that regard especially because Germany is the main beneficiary of the euro. It was alleged at the time that this was a dilatory tactic designed to postpone a domestically unpopular decision until after crucial regional elections. But why would voters allow themselves to be misled like that? And why did Merkel agree to the bailout before the elections took place? To analyze how citizen preferences affect international cooperation, we develop a game-theoretic model of the four-way interaction between two governments that must coordinate a response to a crisis affecting both countries but who also must face the polls domestically with an electorate that might be uncertain whether a response is necessary. We find that, paradoxically, governments that stand to receive the greatest benefits from international cooperation face the greatest obstacles to implementing the required policies even when voters would want them to. We show how the model can rationalize Merkel's electoral strategy and why her party suffered at the polls when the strategy went off the rails.</jats:p

Coexistence between fluid and crystalline phases of proteins in photosynthetic membranes

Photosystem II (PSII) and its associated light-harvesting complex II (LHCII) are highly concentrated in the stacked grana regions of photosynthetic thylakoid membranes. Within the membrane, PSII-LHCII supercomplexes can be arranged in disordered packings, ordered arrays, or mixtures thereof. The physical driving forces underlying array formation are unknown, complicating attempts to determine a possible functional role for arrays in regulating light harvesting or energy conversion efficiency. Here we introduce a coarse-grained model of protein interactions in coupled photosynthetic membranes, focusing on just two particle types that feature simple shapes and potential energies motivated by structural studies. Reporting on computer simulations of the model's equilibrium fluctuations, we demonstrate its success in reproducing diverse structural features observed in experiments, including extended PSII-LHCII arrays. Free energy calculations reveal that the appearance of arrays marks a phase transition from the disordered fluid state to a system-spanning crystal, which can easily be arrested by thermodynamic constraints or slow dynamics. The region of fluid-crystal coexistence is broad, encompassing much of the physiologically relevant parameter regime. Our results suggest that grana membranes lie at or near phase coexistence, conferring significant structural and functional flexibility to this densely packed membrane protein system.Comment: 11 pages, 5 figure

Double swivel toggle release

A pyrotechnic actuated structural release device is disclosed which is mechanically two fault tolerant for release. The device comprises a fastener plate and fastener body each attachable to one of a pair of structures to be joined. The fastener plate and the fastener body are fastened by a dual swivel toggle member. The toggle member is supported at one end on the fastener plate and mounted for universal pivotal movement thereon. Its other end is received in a central opening in the fastener body, and has a universally mounted retainer ring member. The toggle member is restrained by three retractable latching pins symmetrically disposed in equiangular spacing about the axis of the toggle member and positionable in latching engagement with the retainer ring member on the toggle member. Each pin is retractable by a pyrotechnic charge, the expanding gases of which are applied to a pressure receiving face on the latch pins to effect retraction from the ring member. While retraction of all three pins releases the ring member, the fastener is mechanically two fault tolerant since the failure of any single one or pair of the latch pins to retract results in an asymmetrical loading on the ring member and its dual pivotal movement ensures a release