389 research outputs found
Studies on the aetiology of kiwifruit decline: interaction between soil-borne pathogens and waterlogging
Aims: In 2012, Italian kiwifruit orchards were hit by a serious root disease of unknown aetiology (kiwifruit decline, KD) that still causes extensive damage to the sector. While waterlogging was soon observed to be associated with its outbreak, the putative role of soil microbiota remains unknown. This work investigates the role of these two factors in the onset of the disease. Methods: Historical rainfall data were analysed to identify changes that might explain KD outbreak and mimic the flooding conditions required to reproduce the disease in a controlled environment. A greenhouse experiment was thus designed, and vines were grown in either unsterilized (U) or sterilized (S) soil collected from KD-affected orchards, and subjected (F) or not (N) to artificial flooding. Treatments were compared in terms of mortality rate, growth, and tissue modifications. Results: KD symptoms were only displayed by FU-treated vines, with an incidence of 90%. Ultrastructural observations detected tyloses and fibrils in the xylem vessels of all plants, irrespective of the treatment. Phytopythium vexans and Phytopythium chamaehyphon, isolated from roots of FU plants, emerged as the associated microorganisms. Conclusions: We succeeded in reproducing KD under controlled conditions and confirmed its association with both waterlogging and soil-borne microorganism(s)
Vulcani: esplosioni ed effusioni
Si tratta dei pannelli realizzati per la mostraVulcani: Esplosioni ed effusioni
Festival della Scienza di Genova 2007
Palazzo Ducale – Sottoporticato, Genova
Una nuova mostra interattiva delll’Istituto Nazionale di Geofisica e Vucanologia, alla scoperta dei segreti del nostro pianeta e del mondo spettacolare dei vulcani.
Organizzato come un “racconto”, è un lungo viaggio dalla nascita Terra ad oggi che aiuta a comprendere il ruolo fondamentale dei vulcani nella storia del nostro pianeta. Inizia con una proiezione 3d seguita da un filmato spettacolare e coinvolgente di eruzioni vulcaniche. Nella mostra si incontrano poi un grande modello di vulcano che può essere “acceso” in modalità interattiva, producendo un’eruzione esplosiva con gran fragore, sezioni di vulcano per scoprire “cosa c’è sotto”, plastici associati ad una speciale proiezione che permette di visualizzare sia l’eruzione sia l’interno del vulcano. E ancora rocce vulcaniche e un laboratorio per esperienze guidate, per capire il meccanismo che provoca l’eruzione, studiando il legame tra gas, pressione ed esplosione, anche utilizzando ulteriori modellini di vulcano.
Il fatto che spesso le eruzioni vulcaniche siano accompagnate da attivitĂ sismica ci introduce alla parte finale della mostra, dedicata ai terremoti.
L’obiettivo complessivo della mostra è quello di comunicare e far comprendere l’importanza del lavoro di ricerca e di controllo che svolge l’INGV e il riflesso che questo ha nella vita di ciascuno di noi. Si tratta, in sostanza, di “raccontare” le attività scientifiche svolte dall’Istituto inquadrandole dal punto di vista del visitatore.Con i contributi dell’Associazione per il Festival della Scienza e del Dipartimento della Protezione CivilePublished5.8. TTC - Formazione e informazionereserve
The relationships between regional Quaternary uplift, deformation across active normal faults and historical seismicity in the upper plate of subduction zones: The Capo D’Orlando Fault, NE Sicily
In order to investigate deformation within the upper plate of the Calabrian subduction zone we have mapped and modelled a sequence of Late Quaternary palaeoshorelines tectonically-deformed by the Capo D’Orlando normal fault, NE Sicily, which forms part of the actively deforming Calabrian Arc. In addition to the 1908 Messina Strait earthquake (Mw 7.1), this region has experienced damaging earthquakes, possibly on the Capo D’Orlando Fault, however, it is not considered by some to be a potential seismogenic source. Uplifted Quaternary palaeoshorelines are preserved on the hangingwall of the Capo D’Orlando Fault, indicating that hangingwall subsidence is counteracted by regional uplift, likely because of deformation associated with subduction/collision. We attempt to constrain the relationship between regional uplift, crustal extensional processes and historical seismicity, and we quantify both the normal and regional deformation signals. We report uplift variations along the strike of the fault and use a synchronous correlation technique to assign ages to palaeoshorelines, facilitating calculation of uplift rates and the fault throw-rate. Uplift rates in the hangingwall increase from 0.4 mm/yr in the centre of the fault to 0.89 mm/yr beyond its SW fault tip, suggesting 0.5 mm/yr of fault related subsidence, which implies a throw-rate of 0.63 ± 0.02 mm/yr, and significant seismic hazard. Overall, we emphasise that upper plate extension and related vertical motions complicate the process of deriving information on the subduction/collision process, such as coupling and slip distribution on the subduction interface, parameters that are commonly inferred for other subduction zones without considering upper plate deformation
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