Mnemosyne y el proyecto Trans-formare, lecturas de la trasformación del Museo Frederic Marès de Barcelona

El artículo que presentamos a continuación recoge el proyecto Trans formare. Lecturas de la Transformación del Museo Frederic Marès, relatando la experiencia de ocho artistas vinculados al Equipo Confluencias [The Crossing Lab] de la Facultat de Belles Arts de la Universidad de Barcelona (convenios ref. UB 007095 y UB 008992), que a lo largo del período de renovación del Museu Frederic Marès de Barcelona (2009-2011) han revisitado las salas de este espacio museográfico en tránsito. Durante estas circunstancias especiales, las obras, protagonistas del Museo, carentes de su aura habitual y de la rigidez del contexto expositivo, han permitido una proximidad y una cercanía poco corrientes; siendo esta particularidad el punto de partida de Trans formare: una investigación en torno al objeto artístico y su imagen, a través de las experiencias de transformación y memoria. Asimismo, el proyecto ha buscado releer el trabajo de Aby Warburg, sus propuestas de catalogación iconográfica y, muy especialmente, sus Mnemosyne, permitiendo con ello aportar nuevas lecturas y perspectivas interpretativas al recorrido museográfico. En este artículo se pretende, pues, analizar y describir el proyecto, sus bases ideológicas y sus resultados, que han dado lugar a una exposición temporal con la que el Museo Marès ha reabierto sus puertas, y que puede visitarse hasta enero de 2012.

Full instability behavior of N-dimensional dynamical systems with a one-directional nonlinear vector field

We show how certain N-dimensional dynamical systems are able to exploit the full instability capabilities of their fixed points to do Hopf bifurcations and how such a behavior produces complex time evolutions based on the nonlinear combination of the oscillation modes that emerged from these bifurcations. For really different oscillation frequencies, the evolutions describe robust wave form structures, usually periodic, in which selfsimilarity with respect to both the time scale and system dimension is clearly appreciated. For closer frequencies, the evolution signals usually appear irregular but are still based on the repetition of complex wave form structures. The study is developed by considering vector fields with a scalar-valued nonlinear function of a single variable that is a linear combination of the N dynamical variables. In this case, the linear stability analysis can be used to design N-dimensional systems in which the fixed points of a saddle-node pair experience up to N21 Hopf bifurcations with preselected oscillation frequencies. The secondary processes occurring in the phase region where the variety of limit cycles appear may be rather complex and difficult to characterize, but they produce the nonlinear mixing of oscillation modes with relatively generic features

Relaxation and derelaxation of pure and hydrogenated amorphous silicon during thermal annealing experiments

The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated amorphous silicon (a-Si:H) materials, that occurs during thermal annealing experiments, has been analyzed by Raman spectroscopy and differential scanning calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by relaxation of the Si-Si network strain but it reveals a derelaxation of the bond angle strain. Since the state of relaxation after annealing is very similar for pure and hydrogenated materials, our results give strong experimental support to the predicted configurational gap between a-Si and crystalline silicon

Speed of travelling fronts: Two-dimensional and ballistic dispersal probability distributions

The speed of traveling fronts for a two-dimensional model of a delayed reactiondispersal process is derived analytically and from simulations of molecular dynamics. We show that the one-dimensional (1D) and two-dimensional (2D) versions of a given kernel do not yield always the same speed. It is also shown that the speeds of time-delayed fronts may be higher than those predicted by the corresponding non-delayed models. This result is shown for systems with peaked dispersal kernels which lead to ballistic transport

HIV-1 immune activation induces siglec-1 expression and enhances viral trans-infection in blood and tissue myeloid cells

Background: Myeloid cells are key players in the recognition and response of the host against invading viruses. Paradoxically, upon HIV-1 infection, myeloid cells might also promote viral pathogenesis through trans-infection, a mechanism that promotes HIV-1 transmission to target cells via viral capture and storage. The receptor Siglec-1 (CD169) potently enhances HIV-1 trans-infection and is regulated by immune activating signals present throughout the course of HIV-1 infection, such as interferon α (IFNα). Results: Here we show that IFNα-activated dendritic cells, monocytes and macrophages have an enhanced ability to capture and trans-infect HIV-1 via Siglec-1 recognition of viral membrane gangliosides. Monocytes from untreated HIV-1-infected individuals trans-infect HIV-1 via Siglec-1, but this capacity diminishes after effective antiretroviral treatment. Furthermore, Siglec-1 is expressed on myeloid cells residing in lymphoid tissues, where it can mediate viral trans-infection. Conclusions: Siglec-1 on myeloid cells could fuel novel CD4+ T-cell infections and contribute to HIV-1 dissemination in vivo.