ALCUNE CONSIDERAZIONI SULLA EVOLUZIONE STORICA RECENTE DELL’ARNO FIORENTINO E LA RELATIVA NARRAZIONE

l tronco fiorentino dell’Arno, nella sua evoluzione storica, ha cambiato ripetutamente e profondamente la propria configurazione al mutare delle condizioni al contorno di tipo sociale ed economico. Ciò è avvenuto parallelamente ad una estesa serie di eventi calamitosi per i quali si trova una narrazione e una conseguente analisi tecnica portata a livelli di dettaglio singolarmente elevati. Si riportano alcuni aspetti salienti di questo percorso che ha avuto importanti riflessi negli effetti degli eventi di piena succedutisi nel tempo e nella configurazione della difesa idraulica alla scala locale. In particolare si discutono gli interventi degli ultimi centocinquanta anni, a partire da quelli eseguiti a seguito dell’evento del 1844 e del 1966, che hanno comportato le variazioni più significative in termini di assetto delle sponde, del fondo e della conduttività idraulica. Lo studio non ha pretesa di completezza, né lo spazio a disposizione lo permetterebbe, ma segnala alcune questioni rilevanti al dibattito su questo cinquantesimo anniversario dell’evento del 1966

Desarrollo de un modelo animal in vitro para evaluar nuevos fármacos para el tratamiento del ojo seco

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Óptica y Optometría, leída el 19/02/2019In the ophthalmic field, multifactorial pathologies such as Dry Eye Disease (DED) and cataract are largely studied in living animal models that can fail to precisely mirror the complexity of these conditions in humans. Recent advances in biomedical technologies have improved the reliability of in-vitro/ex-vivo animal alternatives, and to date, the corneal and crystalline lens tissue have been independently maintained physiologicallystable for 10 days. This thesis details the development of a novel and complete ex-vivo anterior eye model, which is capable of sustaining both the cornea and crystalline lens in a physiologically stable state in loco for 7 days. The platform is based on porcine eyes, which represent a high quality and reliable human tissue source substitute, and being slaughterhouse waste, also perfectly align the project with the 3Rs principle of replacing, refining and reducing living animal experimentation...Dentro del campo oftalmológico, patologías multifactoriales como Enfermedad del Ojo Seco (EOS) y Cataratas son ampliamente estudiadas a través de modelos animales que no reproducen con exactitud estas condiciones en humanos debido a su complejidad. Los recientes avances en la tecnología biomédica han mejorado la fiabilidad de modelos animales in-vitro/ex-vivo, y hasta el momento, el tejido de la córnea y cristalino se han mantenido fisiológicamente estables de forma independiente durante 10 días. Esta tesis describe el desarrollo de un nuevo y completo modelo de ojo anterior ex vivo, que es capaz de mantener tanto la córnea como el cristalino en un estado fisiológico estable durante 7 días. La plataforma se basa en ojos porcinos, que representan una fuente alternativa al tejido humano de alta calidad y fiable, y al tratarse de residuos de matadero, también alinea perfectamente el proyecto con el principio 3Rs de reemplazar, refinar y reducir la experimentación con animales vivos...Fac. de Óptica y OptometríaTRUEunpu

Development of an in-vitro animal model to evaluate novel pharmaceutical approaches to DED management

In the ophthalmic field, multifactorial pathologies such as Dry Eye Disease (DED) andcataract are largely studied in living animal models that can fail to precisely mirror thecomplexity of these conditions in humans. Recent advances in biomedical technologieshave improved the reliability of in-vitro/ex-vivo animal alternatives, and to date,the corneal and crystalline lens tissue have been independently maintained physiologicallystable for 10 days. This thesis details the development of a novel and complete ex-vivo anterior eye model,which is capable of sustaining both the cornea and crystalline lens in a physiologicallystable state in loco for 7 days. The platform is based on porcine eyes, which representa high quality and reliable human tissue source substitute, and being slaughterhousewaste, also perfectly align the project with the 3Rs principle of replacing, refining andreducing living animal experimentation. The model is modular and scalable, allowingfor the maximisation of experimental reliability, and the minimisation of wasteand energy use. In addition, the whole system is designed to be fitted in a laminarflow cabinet, avoiding external biological contamination, and is easily transportablebetween tissue engineering laboratories, maximising accessibility. The model was validated estimating cell viability over time. Stromal fibroblasts werefound to be viable up to the seventh day of culture, and corneal and crystalline lenstissue maintained their transparency over the culturing period. Dry Eye Disease wassuccessfully induced in the model by irrigating the ocular surface every 40s, and validatedusing impression cytology technique. Moreover, due to the unique presence inloco of the crystalline lens, the model was also used as a platform to perfect cataractsurgery and successfully implant intraocular lenses (IOLs). The novel and complete ex-vivo anterior eye model developed in this thesis providesfurther insights into pre-clinical anterior segment investigations in ophthalmology,taking a step forward toward bridging the existing gap between in-vitro and in-vivobiomedical technologies

Beginning of sediment transport of incoherent grains in shallow shear flows

ln this paper the main results of an ex peri men tal investigation on the beginning of sediment transport of incoherent granular materials in shallow viscous llows are presented. The experiments, performed in a laboratory !lume in both laminar and smooth turbulent llow conditions, complement the data already available in literature, and confirm that the hyperbolic trend shown by the Shields curve when the grain Reynolds number X decreases to zero is not supported by experimental evidence. In addition, they confirm the Yalin and Karahan (1979) hypothesis on the existence of a distinct curve for the inception of sediment tran sport in viscous dominated llows. On the basis of the observed phenomenology, we propose to interpret the process as a function of the probability distribution of the repose angle of the grains of the erodible bed. Accordingly, a simple mechanical relati on is derived that explains the pattern exhibited by the experimental data

Sharing data and maps on flood and landslide hazards, vulnerability, and related risk reduction Public Works via a web platform at national scale: the case of #italiasicura

Italy has experienced many flood and landslide disasters, during and after which the local intrinsic risk management levels have been very different. This problem can be managed, in cooperation with other policies, through improvements in risk awareness and preparedness. With this aim in mind, #italiasicura web platform has been developed, based on a geographic “non-GIS” interface (although working with an underlying database system) to show hazard maps and risk reduction Public Works in the whole of Italy, up to local level. Such an instrument operates as an innovative “social tool”, developed to be used both by decision/makers and citizens, giving the possibility, at any stage of the user experience on the platform, of an easy information sharing via social media. Such a kind of tool represents an opportunity of increasing the knowledge linked to flood and landslide hazards and structural defence strategies. As a matter of fact, the #italiasicura web platform is based upon three pages: one, geographic, presenting hazard, risk and physical infrastructures; the second, also geographic, focused on national emergencies; the third, text and graphics, allowing a number of simple queries and rankings of the main parameters related to the topics of the platform. From a technical point of view, although there is a map on the screen and an underlying database system (permanently updated automatically), neither layers to be switched on and off are present nor any other typical GIS user interface function. All information is presented based upon the coordinates and the zoom level, to allow a better user experience, particularly with the responsive version toward mobiles. Both graphic pages open on the national map. A text box self customizes itself, aggregating data on the actual zoom level; the main navigation actions are performed moving the mouse and acting on the mouse wheel. A new URL is generated at any event generated by the user. Data shown and related web analytics are an interesting source of information for refining risk management strategies and studies; at the same time, they will allow a greater involvement of the scientific community and young researchers, enabling them to elaborate bottom-up suggestions to decision makers

A distributed package for sustainable water management: A case study in the Arno basin

MOBIDIC (MOdello di Bilancio Idrologico DIstribuito e Continuo) is a distributed hydrological modelling package for various applications. The main innovations concern: (a) the coupling of the water balance in the soil and vegetation with the surface energy balance, to the benefit of evapotranspiration computation and the use of remotely-sensed maps for calibration and validation; (b) the interaction between groundwater and surface water bodies, (c) the capability of easily managing data on withdrawals of water, reservoir operation and environmental flow. MOBIDIC-WRM can be used as an effective tool for the evaluation of basin scenarios (e.g. effects of changes in land cover/deforestation and irrigation strategies, exploitation policies for groundwater). It provides a reliable hydrological base for the assessment of crisis indicators such as vegetation stress and lack of environmental flow. In this work we present an application in the Arno basin, central Italy. The outcome of applying the package in order to determine the water budget management strategies is discussed. Copyright © 2009 IAHS Press

Effetti del cambiamento climatico e indicatori di stress per le specie ittiche

La definizione di strategie di adattamento ai cambiamenti climatici si articola su un ampio spettro di scale spaziali e temporali, e richiede un concerto di azioni diverse, integrate e sussidiarie a seconda del contesto considerato. L’Autorità di bacino del fiume Arno ha sviluppato da tempo una linea di ricerca tesa a valutare le peculiarità del cambiamento globale in atto nel territorio del bacino, attraverso l’attività di uno specifico laboratorio territoriale permanente. I risultati mostrano la validità dell’approccio e l’evidente deriva che caratterizza la non stazionarietà del regime delle portate alle scale d’interesse per la pianificazione territoriale. Ai fini del presente lavoro si pone particolare attenzione alla deriva del regime di portata che, a partire dagli anni ’70, mostra una sensibile riduzione della disponibilità idrica e una progressiva asimmetria rispetto agli usuali contributi stagionali. Tale effetto al suolo rispecchia gli aspetti del cambiamento climatico in termini di distribuzione spaziale e temporale delle precipitazioni e dell’andamento delle temperature. Tra gli indicatori di vulnerabilità l’evoluzione dell’Area Disponibile Ponderata (ADP, Bovee et al. 1998), in funzione dei diversi regimi, si è mostrata un indicatore efficace al quale è possibile affiancare specifici segnali di stress. Per questo si è effettuato un rilievo di dettaglio del fondo dell’alveo in un tronco posto nella sezione di chiusura del bacino laboratorio e, fissata la specie bersaglio nel barbo in fase riproduttiva, si è calcolata l’ADP utilizzando un modello idrodinamico bidimensionale a elementi finiti. Si è poi effettuata l’analisi della serie storica (quasi secolare) delle portate osservate scegliendo, come riferimento, la permanenza della portata media giornaliera al disotto del 50% e del 70% dell’ADP per due giorni consecutivi ed oltre. I risultati mostrano una forte dinamica del dato che, sopratutto negli ultimi dieci anni, indica un incremento notevole del numero di eventi e dei giorni di permanenza. Mostrano inoltre la validità dell’approccio seguito che tende a fornire una indispensabile dimensione temporale all’analisi alla scala del meso- e del microhabitat