Ressenyes

Index de les obres ressenyades: Joan ROMERO, Geopolítica y gobierno del territorio en Españ

On the evaluation of debris flows dynamics by means of mathematical models

International audienceThe prediction of debris flow dynamic characteristics in a debris flow prone torrent is generally made through the investigation of past events. This investigation can be carried out through a survey of the marks left by past debris flows along the channel and through a detailed analysis of the type and shape of the deposits found on the debris fan. The rheological behaviour of future debris flows can then be inferred from the results of these surveys and their dynamic characteristics can be estimated applying well known formulas proposed in literature. These latter will make use of the assumptions on the rheological behaviour previously made. This type of estimation has been performed for a debris flow occurred in an instrumented basin, on the North-Eastern Italian Alps, in 1996 and the results have been compared to those obtained by means of a mathematical simulation. For the calibration of the mathematical model the limnographs recorded by three different ultrasonic gauges installed along a torrent reach on the fan were used. The comparison evidenced the importance of time data recordings for a correct prediction of the debris flows dynamics. Without the availability of data recordings, the application of formulas based only on assumptions derived from field analysis could be misleading

Assessing the EU pressure for rules change: perception by southern Mediterranean energy regulators

This paper analyses the perception of the EU as rules promoter of energy regulatory agencies in four southern Mediterranean countries: Algeria, Egypt, Turkey and Jordan. The restructuring of the energy sector, as promoted by the EU in the southern Mediterranean region, is considered as the main criteria to evaluate the EU modes of external governance. EU modes of governance are assessed in a comparative way through a perception survey. The case studies have been selected due to their relevance in terms of energy sector restructuring and energy exchanges, Among the modes of governance considered, the top-down approach appears as the most promising mode of rules diffusio

Espai públic enjardinat : impactes ambientals, model urbà i individualització a la Regió Metropolitana de Barcelona

En un context de segona modernitat en què té lloc un procés de difusió de la ciutat, mitjançant l'establiment d'un model urbà basat en la privacitat a través del predomini d'habitatges unifamiliars, l'espai públic enjardinat desenvolupa un paper de gran rellevància a l'hora de potenciar la col·lectivitat i les relacions socials. Però la concentració d'aquests espais en zones de ciutat compacta limita els seus efectes en el difús, d'aquesta manera es mostren dos models d'individualització diferenciats en funció del teixit urbà. A més, l'espai públic enjardinat té uns impactes ambientals que cal conèixer, especialment pel que fa als recursos hídrics, i cal veure fins a quin punt els beneficis socials de la jardineria pública poden compensar els seus impactes ambientals.En un contexto de segunda modernidad donde tiene lugar un proceso de difusión de la ciudad, en que se desarrolla un modelo urbano sustentado en la privacidad a través del predominio de viviendas unifamiliares, el espacio público ajardinado tiene un papel de gran relevancia a la hora de potenciar la colectividad y las relaciones sociales. Sin embargo, la concentración de estos espacios públicos en zonas de ciudad compacta limita sus efectos en el difuso, mostrando así dos modelos de individualización diferenciados en función del tejido urbano. Además, el espacio público ajardinado tiene unos impactos ambientales que deben conocerse, especialmente en cuanto a los recursos hídricos se refiere. Será conveniente averiguar hasta qué punto los beneficios sociales de la jardinería pública pueden compensar sus impactos ambientales.En un contexte de seconde modernité où il y a eu lieu un procès de diffusion de la citée, établissant un model urbain basé en la intimité avec une majorité de maisons unifamiliaux, l'espace public jardiné a un rôle de grande relevance favorisant la collectivité et les relations sociales. Mais la concentration de ces espaces à la citée compacte limite leur effets à la citée diffuse, montrant deux models d'individualisation selon le model urbain. En plus, l'espace publique jardiné a des impacts sur l'environnement qu'il faut connaître, en spécial ceux qui affectent les ressources hydriques, et il faut analyser si les avantages sociaux des jardins publics peuvent compenser leurs impacts sur l'environnement.In a second modernity context where a process of city diffusion is taking place, with the establishment of an urban model based on the privacy through a majority presence of singlefamily houses, public gardened space plays an important role favouring collectivity and social relationships. But the concentration of these spaces in compact city areas limits its effects into the diffuse city, showing two models of individualization depending on the urban model. Furthermore, public gardened space has environmental impacts that should be known, especially in what water resources concerns. Therefore, it is necessary to analyze whether social benefits of public gardening could compensate or not for their environmental impacts

Analysis of different water-sediment flow processes in a mountain torrent

International audienceSediment ? water flows occurring in mountain torrents may show a variety of regimes, ranging from water flows with transport of individual particles to massive transport of debris, as it occurs in case of debris flows. Sometimes it is possible, by means of accurate field investigations, to identify the kind of processes that took place in a torrent after the occurrence of an event. However this procedure cannot give indications regarding the development of the process in time. In fact, because of the frequent presence of different surges within the same event, the rheological characteristics of an event can be detected only when some recorded hydrographs or videos are available. For the same reason, since the rheological behaviour of the flow changes according to the solid concentration, the analysis of the materials deposited on the debris fan cannot directly give any information on the particular types of flow that took place: a possible alternation in time of different water sediment surges with different concentrations may have occurred, during the same event. The installation of ultrasonic gauges or videocameras along the torrent might give more information on this issue. To this regard, the analysis of a flow event which occurred in 2002 in the Moscardo torrent watershed, instrumented for debris flow monitoring, has been undertaken, studying the hydrographs recorded at two different ultrasonic gauges placed at a known distance along the torrent. An empirical flow resistance law has been applied analysing the values assumed by its parameters after calibration. The application of this law actually spans from debris flow and immature debris flow to bed load transport. Only field observations and surveys, together with ultrasonic data, may allow to clearly discriminate which type of flow really occurred. The analysis confirms that different water sediment surges alternated in time while the mathematical simulation of the flow compared with field observations revealed that the dynamic behaviour of the flow was different from that of previous debris flow events and might reflect, among the different types of possible rheological behaviors, a dilatant-type behavior typical of stony debris flows

Self-assembling nanoparticles containing dexamethasone as a novel therapy in allergic airways inflammation.

Nanocarriers can deliver a wide variety of drugs, target them to sites of interest, and protect them from degradation and inactivation by the body. They have the capacity to improve drug action and decrease undesirable systemic effects. We have previously developed a well-defined non-toxic PEG-dendritic block telodendrimer for successful delivery of chemotherapeutics agents and, in these studies, we apply this technology for therapeutic development in asthma. In these proof-of-concept experiments, we hypothesized that dexamethasone contained in self-assembling nanoparticles (Dex-NP) and delivered systemically would target the lung and decrease allergic lung inflammation and airways hyper-responsiveness to a greater degree than equivalent doses of dexamethasone (Dex) alone. We found that ovalbumin (Ova)-exposed mice treated with Dex-NP had significantly fewer total cells (2.78 ± 0.44 × 10(5) (n = 18) vs. 5.98 ± 1.3 × 10(5) (n = 13), P<0.05) and eosinophils (1.09 ± 0.28 × 10(5) (n = 18) vs. 2.94 ± 0.6 × 10(5) (n = 12), p<0.05) in the lung lavage than Ova-exposed mice alone. Also, lower levels of the inflammatory cytokines IL-4 (3.43 ± 1.2 (n = 11) vs. 8.56 ± 2.1 (n = 8) pg/ml, p<0.05) and MCP-1 (13.1 ± 3.6 (n = 8) vs. 28.8 ± 8.7 (n = 10) pg/ml, p<0.05) were found in lungs of the Dex-NP compared to control, and they were not lower in the Dex alone group. In addition, respiratory system resistance was lower in the Dex-NP compared to the other Ova-exposed groups suggesting a better therapeutic effect on airways hyperresponsiveness. Taken together, these findings from early-stage drug development studies suggest that the encapsulation and protection of anti-inflammatory agents such as corticosteroids in nanoparticle formulations can improve efficacy. Further development of novel drugs in nanoparticles is warranted to explore potential treatments for chronic inflammatory diseases such as asthma

Influence of rheology on debris-flow simulation

Systems of partial differential equations that include the momentum and the mass conservation equations are commonly used for the simulation of debris flow initiation, propagation and deposition both in field and in laboratory research. The numerical solution of the partial differential equations can be very complicated and consequently many approximations that neglect some of their terms have been proposed in literature. Many numerical methods have been also developed to solve the equations. However we show in this paper that the choice of a reliable rheological model can be more important than the choice of the best approximation or the best numerical method to employ. A simulation of a debris flow event that occurred in 2004 in an experimental basin on the Italian Alps has been carried out to investigate this issue. The simulated results have been compared with the hydrographs recorded during the event. The rheological parameters that have been obtained through the calibration of the mathematical model have been also compared with the rheological parameters obtained through the calibration of previous events, occurred in the same basin. The simulation results show that the influence of the inertial terms of the Saint-Venant equation is much more negligible than the influence of the rheological parameters and the geometry. A methodology to quantify this influence has been proposed