IL PRESENTE DEL PASSATO

Non molte città al mondo presentano una stratificazione storica tanto densa quanto Roma. Il fatto è che essa dalle sue origini - 741 a.c. - ad oggi non ha conosciuto le catastrofi che hanno segnato la vita di molte altre città. Una continuità pressoché ininterrotta ne ha caratterizzato la costruzione a partire dal XVI secolo, dall’ultimo saccheggio nel 1527; ma anche le devastazioni barbariche in età medievale di ciò che restava della città romana e dei nuovi insediamenti costruiti sulle sue rovine, costituitisi intorno ai presidi della Cristianità, non sono valse a cancellare l’immensa forza dei tracciati, la configurazione dei grandi recinti dei complessi imperiali, la miriade di ville e casali rurali che popolavano il territorio entro e fuori delle mura Aureliane

REPENSANDO 1983-2022

La historia de este proyecto surge al repensarlo. Pocas ciudades en el mundo se pueden jactar de la permanencia en el tiempo de su patrimonio edificado, de la estratificación de las huellas de su pasado - presentes en superficie o en profundidad-, del arraigo de sus estructuras, desde las más antiguas a las más modernas, como lo puede hacer Roma

Orizzonti di senso del progetto contemporaneo. Progettare per chi e in nome di cosa

Detrás de todo encargo arquitectónico, como detrás de cualquier tema de proyecto, se observa la existencia de una dimensión mayor a la inmediatez de las circunstancias. A esta dimensión el proyecto debe referirse para poder desplegar su propia potencialidad y encontrar, al mismo tiempo, el sentido de su propia acción

Sobre las ruinas de la modernidad: El caso del edificio de la Juventud Italiana del Littorio (GIL) en Campobasso

Las circunstancias históricas que rodean este edificio son paradójicas; por un lado ha estado en el centro de disputas entre instituciones y sus respectivas líneas culturales y además, bajo la acción de las contradicciones; demolido en forma parcial y sólo después protegido, al reconocerse su valor tanto histórico, como arquitectónico. El proyecto que exponemos interviene sobre este edificio; una ruina de la modernidad italiana

Spatially: Resolved heterogeneous dynamics in a strong colloidal gel

We re-examine the classical problem of irreversible colloid aggregation, showing that the application of Digital Fourier Imaging (DFI), a class of optical correlation methods that combine the power of light scattering and imaging, allows one to pick out novel useful evidence concerning the restructuring processes taking place in a strong colloidal gel. In particular, the spatially-resolved displacement fields provided by DFI strongly suggest that the temporally-intermittent local rearrangements taking place in the course of gel ageing are characterized by very long-ranged spatial correlations

Biopolymer gels with "physical" cross-links: gelation kinetics, aging, heterogeneous dynamics, and macroscopic mechanical properties

Alginate is a natural biopolymer that forms, in the presence of divalent cations, ionic-bound gels typifying a large class of biological gels stabilized by non-covalent cross-links, and displaying a consistent restructuring kinetics. We investigate the kinetics of formation and aging of alginate gels by slow permeation of a curing CaCl2 agent by means of photon correlation imaging, a novel optical technique that allows obtaining the microscopic dynamics of the sample, while retaining at the same time the spatial resolution of imaging techniques. Specifically, the gelling kinetics displays a peculiar non-diffusive behavior, and the subsequent restructuring of the gel structure shares several features in common with the aging of colloidal gels, in particular for what concerns the occurrence of heterogeneous dynamics effects. A comparative analysis of the gel macroscopic mechanical properties at different aging stages further highlights distinctive effects arising from the non-permanent nature of the bonds

The structural role of bacterial eDNA in the formation of biofilm streamers

Across diverse habitats, bacteria are mainly found as biofilms, surface-attached communities embedded in a self-secreted matrix of extracellular polymeric substances (EPS), which enhance bacterial recalcitrance to antimicrobial treatment and mechanical stresses. In the presence of flow and geometric constraints such as corners or constrictions, biofilms can take the form of long, suspended filaments (streamers), which bear important consequences in industrial and clinical settings by causing clogging and fouling. The formation of streamers is thought to be driven by the viscoelastic nature of the biofilm matrix. Yet, little is known about the structural composition of streamers and how it affects their mechanical properties. Here, using a microfluidic platform that allows growing and precisely examining biofilm streamers, we show that extracellular DNA (eDNA) constitutes the backbone and is essential for the mechanical stability of Pseudomonas aeruginosa streamers. This finding is supported by the observations that DNA-degrading enzymes prevent the formation of streamers and clear already formed ones and that the antibiotic ciprofloxacin promotes their formation by increasing the release of eDNA. Furthermore, using mutants for the production of the exopolysaccharide Pel, an important component of P. aeruginosa EPS, we reveal an concurring role of Pel in tuning the mechanical properties of the streamers. Taken together, these results highlight the importance of eDNA and of its interplay with Pel in determining the mechanical properties of P. aeruginosa streamers and suggest that targeting the composition of streamers can be an effective approach to control the formation of these biofilm structures. Significance: Streamers, filamentous bacterial biofilms formed in flowing systems, are ubiquitous in natural and artificial environments, where they cause clogging of devices and spreading of infections. Despite their impact, little is known about the nature and properties of streamers and their response to fluid flow. Here, we uncover the specific contribution of bacterial secreted extracellular DNA and exopolysaccharide Pel, two important components in Pseudomonas aeruginosa biofilms, to the formation and the mechanical properties of the streamers. We then show how this knowledge can be used to control biofilm streamer formation, both to inhibit or to promote it

Una strada parco per la "Città Pontina"

Nel volume è presentato un progetto di parco lineare innervato sulla realizzazione di una pista ciclabile che sfrutta il tracciato ferroviario dismesso della tratta Velletri Terracina. Il parco include aree agricole, siti archeologici e di interesse storico e naturalistico ed una serie di cave dismesse di cui si progetta la rinaturalizzazioned il riuso per servizi del parco. Il progetto prevede inoltre risalite meccaniche ai centri antichi sulla Pedemontana Setina.In this volume is presented a draft innervated linear park on the creation of a bike path that takes advantage of the disused railway line is of Velletri Terracina. The park includes agricultural areas, and archaeological sites of historical and natural interest and a series of disused quarries where you plan to reuse the rinaturalizzazioned for park services. The project also includes the ski lifts to the ancient centers on the foothills Setina

The effect of flow on swimming bacteria controls the initial colonization of curved surfaces

The colonization of surfaces by bacteria is a widespread phenomenon with consequences on environmental processes and human health. While much is known about the molecular mechanisms of surface colonization, the influence of the physical environment remains poorly understood. Here we show that the colonization of non-planar surfaces by motile bacteria is largely controlled by flow. Using microfluidic experiments with Pseudomonas aeruginosa and Escherichia coli, we demonstrate that the velocity gradients created by a curved surface drive preferential attachment to specific regions of the collecting surface, namely the leeward side of cylinders and immediately downstream of apexes on corrugated surfaces, in stark contrast to where nonmotile cells attach. Attachment location and rate depend on the local hydrodynamics and, as revealed by a mathematical model benchmarked on the observations, on cell morphology and swimming traits. These results highlight the importance of flow on the magnitude and location of bacterial colonization of surfaces.Fil: Secchi, Eleonora. Eidgenössische Technische Hochschule Zurich. Institute of Environmental Engineering; SuizaFil: Vitale, Alessandra. Universitat Zurich; SuizaFil: Miño, Gastón Leonardo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Laboratorio de Microscopía Aplicada a Estudios Moleculares y Celulares; Argentina. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; ArgentinaFil: Kantsler, Vasily. University of Warwick; Reino UnidoFil: Eberl, Leo. Universitat Zurich; SuizaFil: Rusconi, Roberto. Humanitas University. Department of Biomedical Sciences; Italia. Humanitas Clinical and Research Center; ItaliaFil: Stocker, Roman. Eidgenössische Technische Hochschule Zurich. Institute of Environmental Engineering; Suiz

The effect of flow on swimming bacteria controls the initial colonization of curved surfaces

The colonization of surfaces by bacteria is a widespread phenomenon with consequences on environmental processes and human health. While much is known about the molecular mechanisms of surface colonization, the influence of the physical environment remains poorly understood. Here we show that the colonization of non-planar surfaces by motile bacteria is largely controlled by flow. Using microfluidic experiments with Pseudomonas aeruginosa and Escherichia coli, we demonstrate that the velocity gradients created by a curved surface drive preferential attachment to specific regions of the collecting surface, namely the leeward side of cylinders and immediately downstream of apexes on corrugated surfaces, in stark contrast to where nonmotile cells attach. Attachment location and rate depend on the local hydrodynamics and, as revealed by a mathematical model benchmarked on the observations, on cell morphology and swimming traits. These results highlight the importance of flow on the magnitude and location of bacterial colonization of surfaces