Il governo integrato delle trasformazioni urbane e delle infrastrutture di trasporto

Il lavoro proposto ha l’obiettivo di evidenziare punti di forza e di debolezza delle diverse pratiche di pianificazione integrata trasporto-territorio, attraverso l’analisi comparativa di casi in diversi contesti urbani. In particolare lo studio si compone di due parti: nella prima vengono riportati i risultati di uno studio di esperienze di pianificazione integrata trasporti pubblici - territorio in diversi contesti internazionali e a tre diverse scale territoriali (l’area vasta, la scala metropolitana e un piccolo centro urbano) mettendo in evidenza gli strumenti di pianificazione, i soggetti coinvolti nella trasformazione ed i risultati. Nella seconda parte si propone un approfondimento al caso di Napoli dove si sta portando avanti uno dei più ambiziosi progetti di riorganizzazione dell’intero sistema di trasporto urbano (Cascetta, 2001). Il caso della città di Napoli costituisce infatti un esempio per le pratiche di integrazione tra programmazione e realizzazione del trasporto pubblico ed interventi di riqualificazione e trasformazione urbana. In particolare lo studio si focalizza su tre diversi esempi di progettazione integrata in cui la costruzione di nuove stazioni della metropolitana diventa occasione di riqualificazione della città storica, trasformazione di aree dimesse e rigenerazione delle periferie

Housing market trend and rail transport investments in the city of Naples

Rail transport investments can influence housing market trends, as demonstrated in the literature. However many empirical researches highlight that different results can derive from different urban context applications and that each case should be threaten separately. It is for this reason that this paper is focused on the single case of the city of Naples, where many rail transport investments have been carried out in the last decades. The aim of this study is to give an interpretation of the housing values changes due to the opening of new metro stations. This study applies GIS tools in order to show the spatial distribution and the intensity of rail impacts in different areas of the urban system from 1994 to 2004. This study shows that the extent of the impacts varies from place to place and the effects intensity requires the presence of several complementary factors such as central location of the new stations and the presence of urban planning policies in the transit corridors. This again testifies how housing market is strictly related to the infrastructures investments planning and urban design

On thermal nucleation of quark matter in compact stars

The possibility of a hadron-quark phase transition in extreme astrophysical phenomena such as the collapse of a supernova is not discarded by the modern knowledge of the high-energy nuclear and quark-matter equations of state. Both the density and the temperature attainable in such extreme processes are possibly high enough to trigger a chiral phase transition. However, the time scales involved are an important issue. Even if the physical conditions for the phase transition are favorable (for a system in equilibrium), there may not be enough time for the dynamical process of phase conversion to be completed. We analyze the relevant time scales for the phase conversion via thermal nucleation of bubbles of quark matter and compare them to the typical astrophysical time scale, in order to verify the feasibility of the scenario of hadron-quark phase conversion during, for example, the core-collapse of a supernova.Comment: 6 pages, 4 figures, talk given at the International Conference SQM2009, Buzios, Rio de Janeiro, Brazil, Sep.27-Oct.2, 200

Phase transition from nuclear matter to color superconducting quark matter: the effect of the isospin

We compute the mixed phase of nuclear matter and 2SC matter for different temperatures and proton fractions. After showing that the symmetry energy of the 2SC phase is, to a good approximation, three times larger than the one of the normal quark phase, we discuss and compare all the properties of the mixed phase with a 2SC component or a normal quark matter component. In particular, the local isospin densities of the nuclear and the quark component and the stiffness of the mixed phase are significantly different whether the 2SC phase or the normal quark phase are considered. If a strong diquark pairing is adopted for the 2SC phase, there is a possibility to eventually enter in the nuclear matter 2SC matter mixed phase in low energy heavy ions collisions experiments. Possible observables able to discern between the formation of the 2SC phase or the normal quark phase are finally discussed.Comment: 9 pages, 8 figure

Increase in environmental temperature affects exploratory behaviour, anxiety and social preference in Danio rerio

The aim of this work is to investigate the effect of a temperature increase on the behaviour of adult zebrafish (Danio rerio) maintained for 21 days at 34 °C (treatment) and 26 °C (control). The temperatures chosen are within the vital range of zebrafish and correspond to temperatures that this species encounters in the natural environment. Previous results showed that the same treatment affects the brain proteome and the behaviour of adult zebrafish by producing alterations in the proteins involved in neurotransmitter release and synaptic function and impairing fish exploratory behaviour. In this study, we have investigated the performance of treated and control zebrafish during environmental exploration by using four behavioural tests (novel tank diving, light and dark preference, social preference and mirror biting) that are paradigms for assessing the state of anxiety, boldness, social preference and aggressive behaviour, respectively. The results showed that heat treatment reduces anxiety and increases the boldness of zebrafish, which spent more time in potentially dangerous areas of the tank such as the top and the uncovered bright area and at a distance from the social group, thus decreasing protection for the zebrafish. These data suggest that the increase in ambient temperature may compromise zebrafish survival rate in the natural environment

Nucleation of quark matter in protoneutron star matter

The phase transition from hadronic to quark matter may take place already during the early post-bounce stage of core collapse supernovae when matter is still hot and lepton rich. If the phase transition is of first order and exhibits a barrier, the formation of the new phase occurs via the nucleation of droplets. We investigate the thermal nucleation of a quark phase in supernova matter and calculate its rate for a wide range of physical parameters. We show that the formation of the first droplet of a quark phase might be very fast and therefore the phase transition to quark matter could play an important role in the mechanism and dynamics of supernova explosions.Comment: v3: fits version published in Physical Review

Nondecaying hydrodynamic interactions along narrow channels

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Particle-particle interactions are of paramount importance in every multibody system as they determine the collective behavior and coupling strength. Many well-known interactions such as electrostatic, van der Waals, or screened Coulomb interactions, decay exponentially or with negative powers of the particle spacing r. Similarly, hydrodynamic interactions between particles undergoing Brownian motion decay as 1/r in bulk, and are assumed to decay in small channels. Such interactions are ubiquitous in biological and technological systems. Here we confine two particles undergoing Brownian motion in narrow, microfluidic channels and study their coupling through hydrodynamic interactions. Our experiments show that the hydrodynamic particle-particle interactions are distance independent in these channels. This finding is of fundamental importance for the interpretation of experiments where dense mixtures of particles or molecules diffuse through finite length, water-filled channels or pore networks.U. F. K. was supported by an ERC starting Grant No. (PassMembrane 261101). S. P. acknowledges funding from a Leverhulme Early Career Fellowship. K. M. was supported by a grant from the EPSRC. E. L. was supported by a Marie Curie CIG grant from the EU

Is contrast-enhanced US alternative to spiral CT in the assessment of treatment outcome of radiofrequency ablation in hepatocellular carcinoma?

Purpose: The present study was conducted to assess the efficacy of contrast-enhanced ultrasound with low mechanical index in evaluating the response of percutaneous radiofrequency ablation treatment of hepatocellular carcinoma by comparing it with 4-row spiral computed tomography. Materials and Methods: 100 consecutive patients (65 men and 35 women; age range: 62 – 76 years) with solitary hepatocellular carcinomas (mean lesion diameter: 3.7cm± 1.1cm SD) underwent internally cooled radiofrequency ablation. Therapeutic response was evaluated at one month after the treatment with triple-phasic contrast-enhanced spiral CT and low-mechanical index contrast-enhanced ultrasound following bolus injection of 2.4 ml of Sonovue (Bracco, Milan). 60 out of 100 patients were followed up for another 3 months. Contrast-enhanced sonographic studies were reviewed by two blinded radiologists in consensus. Sensitivity, specificity, NPV and PPV of contrast-enhanced ultrasound examination were determined. Results: After treatment, contrast-enhanced ultrasound identified persistent signal enhancement in 24 patients (24%), whereas no intratumoral enhancement was detected in the remaining 76 patients (76%). Using CT imaging as gold standard, the sensitivity, specificity, NPV, and PPV of contrast enhanced ultrasound were 92.3% (95% CI = 75.9 – 97.9%), 100% (95% CI = 95.2 – 100%), 97.4% (95% CI = 91.1 – 99.3%), and 100% (95% CI = 86.2 – 100%). Conclusion: Contrast-enhanced ultrasound with low mechanical index using Sonovue is a feasible tool in evaluating the response of hepatocellular carcinoma to radiofrequency ablation. Accuracy is comparable to 4-row spiral CT

Megacities and High Speed Rail systems: which comes first?

A megacity is usually defined as a metropolitan area with a total population in excess of 10 million people. The number of megacities is increasing worldwide. In most agglomerations and megacities, urban planning and public infrastructure can guide the urban development in order to achieve a proper sustainable structure only partially. The extension of cities is in most cases in advance of urban development work and the provision of public facilities (Kotter, 2004). In Europe, apart from London and Paris, megacities are rarer. However, due to the general high density of population in Europe and the short distance between medium and large cities there is the possibility of High Speed Rail (HSR) enables the emergence of groups of cities that will be linked together and thus reap the economic benefits associated with megacities, namely economies of scale, economies of agglomeration and bigger labour markets. In this contribution the authors argue that in some cases, specific facilities can foster the formation of megacities; in fact, this is the case of HSR systems. Specifically, High-Speed trains can be used to solve two different accessibility problems. In the first case, where a point-to-point link is dominant, each train is a potential substitute for an air connection between two cities, i.e. it connects cities (or rather CBDs) at long distance with a direct train connection (Blum et al., 1997).The HSR links between Paris and Lyon, Paris and London and, Tokyo and Osaka, could be seen as examples of this first type of train connection. In the second case, where a HSR network is dominant, the rail system links together many cities and CBDs and, hence, creates a new type of region with a high intra-regional accessibility sharing a common labour market and a common market for household and business services. In this case the HSR binds together cities in a band, where each pair of cities is at a time distance of between 20 minutes and 1 hour, allowing daily commuting. In the U.S., HSR projects are very recent and they will have the role of connecting already formed megacities. An example is the state of California, which is planning an 800-mile HSR service connecting Los Angeles and San Francisco into a two and a half hour trip. On the other hand, Europe, together with Asia, is the leader in HSR systems; in fact the development of HSR has been one of the central features of recent European Union transport infrastructure policy. The proposals for a European HSR network emerged in a report of the 1990 Community of European Railways and this was essentially adopted as the base for what became the European Community’s proposed Trans-European Network for HSR (Vickerman, 1997). In this paper the case studies of Portugal, where the HSR is a work in progress and of Italy, in which some lines have already been built, will be described in detail from the viewpoint of the various kinds of development described above