The Rwandan genocide and the bestiality of representation in 100 Days (2001) and Shooting Dogs (2005)

Copyright © 2010 Intellect Ltd. This article is available open access at the below link.The 1994 Rwandan genocide has been a subject of filmic representation in and outside Africa. This article examines two examples of this portrayal and attempts to put them in the context of western perception of African conflict and suffering and its depiction in feature-length fictionalized films. A close analysis of 100 Days (Nick Hughes, UK/Rwanda) and Shooting Dogs (Michael Caton-Jones, UK/Germany), accompanied by cited interviews with their directors, aims to examine the mechanism of the representation of otherness in a situation when the term others is not a straightforward antonym to us. The argument revolves around the idea that others are always a group defined by a common characteristic (the colour of their skin, cultural identity or suffering), while us consists of individuals whose major qualifying feature is the fact that he or she is, individually and collectively, not like others. Special attention is paid to the difference between formal and character-based othering, as well as to the films' adhesion to western cinematic genres. The consideration is contextualized by the concept of the bestiality of representation, which becomes a manner of positioning an event within a socio-historical and individually cognitive context and determining the dynamic among the experience lived, the experience seen and objectivity. Lastly, the article looks at how the circumstances of the production process directly influence the stylistic and aesthetic choices made in films about the Rwandan genocide. In this, it relies on the examination of the trichotomy of politics, representation and the politics of representation

Mechanical Stretching of Proteins: Calmodulin and Titin

Mechanical unfolding of several domains of calmodulin and titin is studied using a Go-like model with a realistic contact map and Lennard-Jones contact interactions. It is shown that this simple model captures the experimentally observed difference between the two proteins: titin is a spring that is tough and strong whereas calmodulin acts like a weak spring with featureless force-displacement curves. The difference is related to the dominance of the alpha secondary structures in the native structure of calmodulin. The tandem arrangements of calmodulin unwind simultaneously in each domain whereas the domains in titin unravel in a serial fashion. The sequences of contact events during unraveling are correlated with the contact order, i.e. with the separation between contact making amino acids along the backbone in the native state. Temperature is found to affect stretching in a profound way.Comment: To be published in a special bio-issue of Physica A; 14 figure

Chirality and Protein Folding

There are several simple criteria of folding to a native state in model proteins. One of them involves crossing of a threshold value of the RMSD distance away from the native state. Another checks whether all native contacts are established, i.e. whether the interacting amino acids come closer than some characteristic distance. We use Go-like models of proteins and show that such simple criteria may prompt one to declare folding even though fragments of the resulting conformations have a wrong sense of chirality. We propose that a better condition of folding should augment the simple criteria with the requirement that most of the local values of the chirality should be nearly native. The kinetic discrepancy between the simple and compound criteria can be substantially reduced in the Go-like models by providing the Hamiltonian with a term which favors native values of the local chirality. We study the effects of this term as a function of its amplitude and compare it to other models such as with the side groups and with the angle-dependent potentials.Comment: To be published in a special issue of J. Phys.: Cond. Mat. (Bedlewo Workshop

Effects of confinement and crowding on folding of model proteins

We perform molecular dynamics simulations for a simple coarse-grained model of crambin placed inside of a softly repulsive sphere of radius R. The confinement makes folding at the optimal temperature slower and affects the folding scenarios, but both effects are not dramatic. The influence of crowding on folding are studied by placing several identical proteins within the sphere, denaturing them, and then by monitoring refolding. If the interactions between the proteins are dominated by the excluded volume effects, the net folding times are essentially like for a single protein. An introduction of inter-proteinic attractive contacts hinders folding when the strength of the attraction exceeds about a half of the value of the strength of the single protein contacts. The bigger the strength of the attraction, the more likely is the occurrence of aggregation and misfolding

Aqueous Amino Acids and Proteins Near the Surface of Gold in Hydrophilic and Hydrophobic Force Fields

We calculate potentials of the mean force for twenty amino acids in the vicinity of the (111) surface of gold, for several dipeptides, and for some analogs of the side chains, using molecular dynamics simulations and the umbrella sampling method. We compare results obtained within three different force fields: one hydrophobic (for a contaminated surface) and two hydrophilic. All of these fields lead to good binding with very different specificities and different patterns in the density and polarization of water. The covalent bond with the sulfur atom on cysteine is modeled by the Morse potential. We demonstrate that binding energies of dipeptides are different than the combined binding energies of their amino-acidic components. For the hydrophobic gold, adsorption events of a small protein are driven by attraction to the strongest binding amino acids. This is not so in the hydrophilic cases - a result of smaller specificities combined with the difficulty for proteins, but not for single amino acids, to penetrate the first layer of water. The properties of water near the surface sensitively depend on the force field