Vuelta a lo que resultó un comienzo: de géneros literarios y política en “Simbiosis”, de Rodolfo Walsh

“Simbiosis”, aparecido originalmente en 1956, constituye la instancia inicial de la serie de cuentos policiales de Rodolfo Walsh que, extendida hasta 1962, protagonizan Daniel Hernández y el comisario Laurenzi. Pero “Simbiosis” representa, además, un momento de rupturas en la trayectoria de Walsh, rupturas observables a la luz de su obra previa, y que contribuyen a definir la singular posición que el escritor procura adoptar en el campo literario de la época. En la nacionalización del género policial que propone, el cuento a la vez recupera y cuestiona el canon clásico del género, al adoptar motivos de la literatura fantástica cuya operatividad como explicaciones de un delito se asocia a su origen en el saber popular, saber al cual Laurenzi accede como comisario de pueblo. Correlativamente, la equívoca resolución del crimen, debatida entre dos matrices de género, una racional y otra sobrenatural, así como el interrogante sobre la culpabilidad que deja abierto el relato, son resonancias significativas de su contexto histórico, desatendidas aún por la crítica: se trata, en particular, de los debates sobre culpables e inocentes políticos que inició en 1955 el derrocamiento militar del gobierno peronista.

Hierarchical synthesis of complex DSP functions on FPGAs

SoC systems are now being increasingly constructed using a hierarchy of subsystems or silicon Intellectual Property (IP) cores. The key challenge is to use these cores in a highly efficient manner which can be difficult as the internal core structure may not be known. A design methodology based on synthesizing hierarchical circuit descriptions is presented. The paper employs the MARS synthesis scheduling algorithm within the existing IRIS synthesis flow and details how it can be enhanced to allow for design exploration of IP cores. It is shown that by accessing parameterised expressions for the datapath latencies in the cores, highly efficient FPGA solutions can be achieved. Hardware sharing at both the hierarchical and flattened levels is explored for a normalized lattice filter and results are presented.

Resolving genetic functions within microbial populations: In situ analyses using rRNA and mRNA stable isotope probing coupled with single-cell raman-fluorescence in situ hybridization

Prokaryotes represent one-half of the living biomass on Earth, with the vast majority remaining elusive to culture and study within the laboratory. As a result, we lack a basic understanding of the functions that many species perform in the natural world. To address this issue, we developed complementary population and single-cell stable isotope (C-13)-linked analyses to determine microbial identity and function in situ. We demonstrated that the use of rRNA/mRNA stable isotope probing (SIP) recovered the key phylogenetic and functional RNAs. This was followed by single-cell physiological analyses of these populations to determine and quantify in situ functions within an aerobic naphthalene-degrading groundwater microbial community. Using these culture-independent approaches, we identified three prokaryote species capable of naphthalene biodegradation within the groundwater system: two taxa were isolated in the laboratory (Pseudomonas fluorescens and Pseudomonas putida), whereas the third eluded culture (an Acidovorax sp.). Using parallel population and single-cell stable isotope technologies, we were able to identify an unculturable Acidovorax sp. which played the key role in naphthalene biodegradation in situ, rather than the culturable naphthalene-biodegrading Pseudomonas sp. isolated from the same groundwater. The Pseudomonas isolates actively degraded naphthalene only at naphthalene concentrations higher than 30 mu M. This study demonstrated that unculturable microorganisms could play important roles in biodegradation in the ecosystem. It also showed that the combined RNA SIP-Raman-fluorescence in situ hybridization approach may be a significant tool in resolving ecology, functionality, and niche specialization within the unculturable fraction of organisms residing in the natural environment.

Infinite Dimensional Banach spaces of functions with nonlinear properties

The aim of this paper is to show that there exist infinite dimensional Banach spaces of functions that, except for 0, satisfy properties that apparently should be destroyed by the linear combination of two of them. Three of these spaces are: a Banach space of differentiable functions on Rn failing the Denjoy-Clarkson property; a Banach space of non Riemann integrable bounded functions, but with antiderivative at each point of an interval; a Banach space of infinitely differentiable functions that vanish at infinity and are not the Fourier transform of any Lebesgue integrable function.