647 research outputs found
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
Formation of Quark Phases in compact stars and their connection to Gamma-Ray-Bursts
We analyse the occurrence of quiescent times in the temporal structure of the
Gamma-Ray-Bursts (GRBs) light curves. We show that if a long quiescent time is
present, it is possible to divide the total duration of GRBs into three
periods: the pre-quiescence emission, the quiescent time and the
post-quiescence emission. We then discuss a model of the GRBs inner engine
based on the formation of quark phases during the life of an hadronic star.
Within this model the pre-quiescence emission is interpreted as due to the
deconfinement of quark inside an hadronic star and the formation of 2SC quark
matter. The post-quiescence emission is due to the conversion of 2SC into the
Color-Flavor-Locking (CFL) phase. The temporal delay between these two
processes is connected with the nucleation time of the CFL phase in the 2SC
phase and it can be associated with the observed quiescent times in the GRBs
light curves. The stability of CFL cores in compact stars is also discussed.Comment: 6 pages, 3 figures, to appear in the proceedings of 3th International
Conference on Nuclear Physics in Astrophysics (NPAIII), 26 - 31 March 2007
Dresden, German
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
Particle transport across a channel via an oscillating potential
Membrane protein transporters alternate their substrate-binding sites between
the extracellular and cytosolic side of the membrane according to the
alternating access mechanism. Inspired by this intriguing mechanism devised by
nature, we study particle transport through a channel coupled with an energy
well that oscillates its position between the two entrances of the channel. We
optimize particle transport across the channel by adjusting the oscillation
frequency. At the optimal oscillation frequency, the translocation rate through
the channel is a hundred times higher with respect to free diffusion across the
channel. Our findings reveal the effect of time dependent potentials on
particle transport across a channel and will be relevant for membrane transport
and microfluidics application
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
Photosynthetic planulae and planktonic hydroids: contrasting strategies of propagule survival
Settlement delays can be important to prevent propagule waste when proper settling substrates are not immediately available. Under laboratory conditions, the planulae of Clytia viridicans underwent two alternative developmental patterns. Some settled on the bottom, forming a hydranth-gonotheca complex that produced up to four medusae and later either degenerated or gave rise to a hydroid colony. Other planulae settled right below the air-water interface, forming floating colonies that eventually fell to the bottom and settled. Halecium nanum released planulae with a rich population of symbiotic zooxanthellae that survived into a rearing jar for three months. After a long period of apparent quiescence (possibly fuelled by photosynthetic activities of zooxanthellae) the planulae produced new colonies. Both photosynthetic planulae and settlement at the interface air-water allow a delay in the passage from a planktonic to a fully functional benthic life
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