De la planificación a la gestión: Implementación de modelos de ocupación en el territorio. Caso de estudio: Zona norte de Bogotá

Las políticas públicas de ordenamiento territorial contienen múltiples implicaciones. Por un lado, definen visiones de ocupación sobre el territorio y, por el otro, establecen mecanismos para su consecución. La zona norte de Bogotá permanece a la espera de un modelo que permita su ocupación con fines urbanos. La presente investigación presenta las implicaciones y caminos desde los cuáles se ha buscado sustentar las posiciones sobre la ocupación de la zona, como las contraposiciones existentes sobre el modelo de ciudad con el que se asocia. La expansión de la ciudad pone de relieve las discusiones sobre lo que debe ser una ciudad, y cambian en el tiempo de la mano con los discursos, intereses e ideologías dominantes.

L'Activité du professeur: entre ajustement aux besoins d'élèves "scolairement fragilisés" et maintien d'une exigence didactique

L’une des principales difficultés que rencontrent les enseignants auprès de publics «scolairement fragilisés»1 est d’obtenir une réelle activité cognitive de leurs élèves en situation de résolution de problèmes mathématiques. On observe le plus souvent la mise en oeuvre d’un faux-semblant d’activité qui consiste, pour les élèves, à appliquer un algorithme de résolution sans prendre le risque d’être confronté à leur propre ignorance (Lemoyne & Conne, 1999). Notons en préambule que si la réflexion menée jusqu’à présent s’ancre de manière privilégiée dans le champ des apprentissages mathématiques, elle alimente néanmoins une problématique plus générale qui vise une étude approfondie des gestes de médiation mis en oeuvre par les professeurs pour pallier le manque d’engagement de certains élèves dans les tâches scolaires qu’ils leur proposent

''L'intervallo perduto'' nella Metropoli Modern

The city is not only a visual environment, but it is also sonorous and therefore the “unintentional hearing which is much more influencing” is involved in an urban space experience just as sight is. Beginning with Assunto’s consideration in Il paesaggio e l’estetica, the analysis we provide cannot avoid outlining the peculiarities of aestetic fruition of the city seen as a space we cross, in which we live and in which we, as a matter of fact, are agent actors. And it is as a consequence of this peculiarity that silence has a leading role in our urban experience. Seen as a presence of itself, it is a positive value especially if we consider that nowadays modernity is expressed through its absence. It is an absence that reaches its climax in the experience of the metropolis. Besides Assunto, there is another witness of this in Simmel’s The Metropolis and Mental Life from which our analysis cannot leave out of consideration. Given that this analysis is a sort of analytic excursus it develops around a well defined barycentre represented by the acoustic experience of the city that focuses on the presence/absence of silence as a result of modernity. Taking the first steps from Assunto and Simmel’s assumptions, this work takes into account the theme of silence in the metropolis and introduces it as a loss of interval and thus uses the analysis carried out by Dorfles in L’intervallo perduto and in Horror Pleni. The metropolitan experience is highly characterized by a sensory disorientation for which we can detect a “strong” starting, the Great War, which shows a caesura that outlines the edges of a new mental world. It shows the systematic use of modern technique, of its sonorous universe and urbanization which appears as a corollary of this picture.

O pesadelo da amnésia colectiva : um estudo sobre os conceitos de memória, tradição e traços do passado

"Blade Runner", o filme de Ridlley Scott traduzido por "O Caçador de Andróides" - está de volta, dez anos após seu lançamento, trazendo, novamente, as imagens do desenvolvimento tecnológico e declínio urbano retiradas da obra de Philip K. Dicke e veiculando nossos medos e fantasias de perda de identidade e desumanização. O tema, caracterizado tão bem em clássicos do cinema, como "Metropolis", de Fritz Lang; "Tempos Modernos", de Charles Chaplin; e "Citizen Kane", de Orson Welles, não é, portanto, novo e periodicamente volta ao debate.

Honorarios [adaptaciones y refundiciones en De la Cuadra y Aguilera-Malta] (Dossier: Cuatro narradores del 30, relecturas en su centenario)

Se contrasta Honorarios, obra dramática de Aguilera-Malta, y «Honorarios», el cuento de José de la Cuadra que la inspiró. El diálogo entre los dos autores fue explícito en diversos textos, así como en sus respectivos mundos literarios: nombres de personajes, motivos, leyendas, mitos, formas, ideología y demandas, actitudes e intereses. De la Cuadra dialogó a su vez con otros creadores. «Honorarios», e.g., recrea y reinterpreta la figura del mítico fetiche Moloch, según lo representan Metrópolis, del cineasta Fritz Lang, y Salambó, de Gustave Flaubert, la narración aludida es también una refundición en torno al tema del poder omnipresente y cruel, que requiere insaciablemente de víctimas propiciatorias. De igual manera, en su proceso creativo y de búsqueda expresiva, Aguilera-Malta acostumbró remozar y reformular temas en diferentes géneros literarios –como el de la lucha del ser humano frente a las fuerzas hostiles de la naturaleza y la sociedad, interpretado en La isla virgen, El tigre y Jaguar–. En Honorarios, Aguilera-Malta se concentró en hallar la manera de transferir la trama del relato «Honorarios» al género dramático. El resultado es una eficaz refundición, en términos de la perspectiva histórico-política y de reflexiones sobre la función de la literatura.

Las independencias: [respuesta al cuestionario de Manuel Chust] (Dossier: Bicentenario, rastros y revelaciones de la Independencia)

Enrique Ayala es entrevistado por el historiador catalán Manuel Chust sobre la independencia de Hispanoamérica. Ayala plantea que la crisis de 1808 afectó la economía de la metrópoli, pero también posibilitó cambios en las relaciones de poder en las colonias: fue instalándose el control de los señores criollos sobre la tierra y de los comerciantes sobre las economías locales y regionales, la burocracia española debilitada conservó solo el manejo político, lo cual favoreció a las clases dominantes locales. Insiste en que las independencias deben ser vistas como procesos, cuyo éxito fue posible al convocarse a los actores populares e integrarse los esfuerzos de diversas colonias. Visualizar eso, afirma, fue uno de los mayores aportes de Simón Bolívar. Finalmente, no se llega a la Independencia por actos de personalidades determinantes, sino por el peso de protagonistas colectivos: notables criollos, grandes latifundistas y comerciantes de los puertos de primer orden, jefes de los ejércitos e intelectuales, la jerarquía de la Iglesia, y el apoyo británico a los insurgentes.

Ultra High Temperatures #1

Ultra High Temperature #1, initiated by Rebecca Bibby forms the first in an ongoing project which explores the realms of collaboration, performance, writing and publication as artistic vehicle of production, dispersion and progression. With Bibby's text -that re-fictions the futuristic projections of technosexuality in Metropolis (1927)- at its core was launched, printed, compiled and distributed in a live performance by POLLYFIBRE at Eastside Projects in Birmingham. The limited edition printed publication was designed by An Endless Supply whose Risograph stencil printer was used as an instrument in the performed production of the text. As a crude avatar of Rebecca Bibby’s practice, Aikon-II, a mechanically programmed signature machine automatically signed each copy of the text during the performance. POLLYFIBRE's ‘flat-pack’ costumes were on display throughout the duration of the exhibition. POLLYFIBRE is a performance project created by Christine Ellison.

The REFLEX project: Comparing different algorithms and implementations for the inversion of a terrestrial ecosystem model against eddy covariance data

We describe a model-data fusion (MDF) inter-comparison project (REFLEX), which compared various algorithms for estimating carbon (C) model parameters consistent with both measured carbon fluxes and states and a simple C model. Participants were provided with the model and with both synthetic net ecosystem exchange (NEE) of CO2 and leaf area index (LAI) data, generated from the model with added noise, and observed NEE and LAI data from two eddy covariance sites. Participants endeavoured to estimate model parameters and states consistent with the model for all cases over the two years for which data were provided, and generate predictions for one additional year without observations. Nine participants contributed results using Metropolis algorithms, Kalman filters and a genetic algorithm. For the synthetic data case, parameter estimates compared well with the true values. The results of the analyses indicated that parameters linked directly to gross primary production (GPP) and ecosystem respiration, such as those related to foliage allocation and turnover, or temperature sensitivity of heterotrophic respiration, were best constrained and characterised. Poorly estimated parameters were those related to the allocation to and turnover of fine root/wood pools. Estimates of confidence intervals varied among algorithms, but several algorithms successfully located the true values of annual fluxes from synthetic experiments within relatively narrow 90% confidence intervals, achieving >80% success rate and mean NEE confidence intervals <110 gC m−2 year−1 for the synthetic case. Annual C flux estimates generated by participants generally agreed with gap-filling approaches using half-hourly data. The estimation of ecosystem respiration and GPP through MDF agreed well with outputs from partitioning studies using half-hourly data. Confidence limits on annual NEE increased by an average of 88% in the prediction year compared to the previous year, when data were available. Confidence intervals on annual NEE increased by 30% when observed data were used instead of synthetic data, reflecting and quantifying the addition of model error. Finally, our analyses indicated that incorporating additional constraints, using data on C pools (wood, soil and fine roots) would help to reduce uncertainties for model parameters poorly served by eddy covariance data.

Trade-offs and responsiveness of the single-layer urban canopy parametrization in WRF: an offline evaluation using the MOSCEM optimization algorithm and field observations

For an increasing number of applications, mesoscale modelling systems now aim to better represent urban areas. The complexity of processes resolved by urban parametrization schemes varies with the application. The concept of fitness-for-purpose is therefore critical for both the choice of parametrizations and the way in which the scheme should be evaluated. A systematic and objective model response analysis procedure (Multiobjective Shuffled Complex Evolution Metropolis (MOSCEM) algorithm) is used to assess the fitness of the single-layer urban canopy parametrization implemented in the Weather Research and Forecasting (WRF) model. The scheme is evaluated regarding its ability to simulate observed surface energy fluxes and the sensitivity to input parameters. Recent amendments are described, focussing on features which improve its applicability to numerical weather prediction, such as a reduced and physically more meaningful list of input parameters. The study shows a high sensitivity of the scheme to parameters characterizing roof properties in contrast to a low response to road-related ones. Problems in partitioning of energy between turbulent sensible and latent heat fluxes are also emphasized. Some initial guidelines to prioritize efforts to obtain urban land-cover class characteristics in WRF are provided. Copyright © 2010 Royal Meteorological Society and Crown Copyright.

GSHMC: an efficient method for molecular simulation

The hybrid Monte Carlo (HMC) method is a popular and rigorous method for sampling from a canonical ensemble. The HMC method is based on classical molecular dynamics simulations combined with a Metropolis acceptance criterion and a momentum resampling step. While the HMC method completely resamples the momentum after each Monte Carlo step, the generalized hybrid Monte Carlo (GHMC) method can be implemented with a partial momentum refreshment step. This property seems desirable for keeping some of the dynamic information throughout the sampling process similar to stochastic Langevin and Brownian dynamics simulations. It is, however, ultimate to the success of the GHMC method that the rejection rate in the molecular dynamics part is kept at a minimum. Otherwise an undesirable Zitterbewegung in the Monte Carlo samples is observed. In this paper, we describe a method to achieve very low rejection rates by using a modified energy, which is preserved to high-order along molecular dynamics trajectories. The modified energy is based on backward error results for symplectic time-stepping methods. The proposed generalized shadow hybrid Monte Carlo (GSHMC) method is applicable to NVT as well as NPT ensemble simulations.

'Penetrating' foreign lands: contestations over African landscape. A case study from Eastern Zimbabwe

While it was happening, European expansion was often legitimised by evoking frontier images: pioneers setting off from the metropolis, penetrating wilderness in order to open access to resources, like minerals, living-space, and fertile lands. Central to the ideology of the frontier is the notion of 'no-man's land'. These 'pioneers', however, often had to face local inhabitants and their interpretations and uses of this land. Thus it will be argued that contestations over landscape were at the same time battles over the legitimation of European expansion, as well as over local perceptions of this process. Ideologically, contestations by Europeans and Africans become apparent in the sexualisation of landscape. This paper is based on the case study of a Valley in eastern Zimbabwe on the border with Mozambique, and more specifically of two tea estates which were established in the rainforest. Unusually late for the region, European influence in this remote area only began to become significant in the 1950s which were an important turning point regarding land and landscape in the area. These years of great change will be analysed in order to map out different strands of interest by the main parties involved. It will be demonstrated that their readings of landscape translated into contestations over land. A recent example of such a conflict will be given.