Large deep-seated gravitational slide off Ischia volcanic island, Eastern Tyrrhenian sea (Italy)

Ischia island develops at the edge of the shelf area and represents the sub-aerial section of a larger, E-W trending volcanic ridge including others submerged or buried volcanic edifices. In the past decade the island’s offshore has been the object of extensive hydrographic and marine geophysical surveys that have shown the structural complexity of the undersea sections and have overall shown the importance of gravity failures in island’s evolution. In this paper we report a previously unreported deep-seated slump structure and associated surficial mass wasting phenomena which occur off Ischia south-western flank. Recently acquired hydrological and geophysical data lead to identify the morphological features and the internal organization of the failed sediments which spread along the continental slope. The extent of this deep-seated deformations and the deep structural levels involved lead to investigate on the influence played by volcanic processes and regional tectonics on slope failure. The Ischia southern slope was explored through a multibeam survey and a single-channel seismic survey. Acquisition was carried out from aboard the R/V Urania at depths between 400 and 1200 m. The bathymetric data were collected using a hull mounted Reson 8160 multibeam sonar. Resolution resulted in a 20x20 m implemented with 50x50 gridded size provided by a previously collected data. Seismic survey consisted of 6 seismic lines run along the slope spaced 1 km between them and 5 cross lines. The acoustic source used was a 1Kjoule high-energy power supply system with a multi-tips (400) sparker array, fired at 2s time interval. The collected data show that a wide submerged area of 350 km2, between 400 to 1200 m depths is undergoing slow-moving deformation and associated secondary mass wasting phenomena. Morphological features include trenches, counterscarps, bulging and both extensional and contractional features while internal deformations show typical landward dipping reflectors with strong evidence of synsedimentary faulting and asymmetric anticlines. Deformation processes operate at various scales generating folds with wavelength ranging from hundreds meters to kilometers. Extensional and rotational rupture surfaces sole out at various low-angle detachment planes located at depths from few hundreds meters to 1 kilometer in subsurface

Large deep-seated slump structure off Ischia volcanic island, Eastern Tyrrhenian sea (Italy)

Ischia island is located over the Campania sector of Eastern Tyrrhenian margin and represents the sub-aerial section of a larger, E-W trending volcanic ridge including others submerged or buried volcanic edifices. The island itself result from the coalescence of a multitude of small to medium scale eruptions leading to the emplacement of domes, lava flow and pyroclastic deposits and ignimbrites (VEZZOLI et al., 1988) ranging from alkali basalts to trachytes. The oldest basement dates back to 150 ky and crops out along the perimeter of the island especially to the south. Latest eruption occurred in 1302 A.D. and together with strong hydrothermal activity, ground uplift and seismic shaking indicates the presence of a still active magmatic reservoir at depth. Most recent (Holocene) magmatic activity with local volcanic eruptions has clustered in the eastern island’s sector the while central sector is dominated by the Mt. Epomeo, consisting of an ignimbritic tuff (Green tuff Auct.) uplifted of 600-700 m in the past 33ka. In the past decade the island’s offshore has been the object of extensive hydrographic and marine geophysical surveys that have shown the structural complexity of the undersea sections and have overall shown the importance of gravity failures in island’s evolution. In particular a 1.5-3 km3 debris avalanche due to a subaerial and/or submarine flank collapse was emplaced along the steep and unbuttressed island’s flank during pre-historical or even historical times (CHIOCCI & DE ALTERIIS, 2006; de Alteriis et al., 2010) whereas three other similar deposits of comparable volumes were found over the continental shelf to the west and to the north (VIOLANTE et al, 2004; DE ALTERIIS & VIOLANTE, 2009). Here we report a previously unrecognized deep-seated slump structure and associated surficial mass wasting phenomena which occur off Ischia south-western flank. Recently acquired hydrological and geophysical data lead to identify the morphological features and the internal organization of the failed sediments which spread along the continental slope. The extent of this deep-seated deformations and the deep structural levels involved lead to investigate on the influence played by volcanic processes on slope failure. DATA AND METHODS Our dataset was acquired during the geophysical cruise PECOS 2010 carried out on R/V Urania (Consiglio Nazionale delle Ricerche, CNR, Italy) between December 22th 2010 and January 2nd 2011 in the frame of a project leaded by Istituto per l’Ambiente Marino Costiero, (IAMC-CNR), Naples-Italy with the collaboration of Dipartimento di Scienze della Terra e del Mare (Palermo University), Palermo-Italy regarding coastal and offshore slope instability in the Bay of Napoli. The Ischia southern slope was explored through a multibeam survey and a single-channel seismic survey. Acquisition was carried out between 400 and 1200 m. The bathymetric data were collected using a hull mounted Reson 8160 multibeam sonar. Resolution resulted in a 20x20 m implemented with 50x50 gridded size provided by a previously collected data. The seismic survey consisted of 6 dip-lines NNE-SSW run along the slope and 5 cross lines parallel to the slope totalling 170 km. Average spacing between diplines was slightly less than 1 km while spacing between crosslines was variable from 1.2 to 2.5 km. NNE-SSW and WNW-ESE directions. The acoustic source used was a 1Kjoule high-energy power supply system with a multitips (400) sparker array, fired at 2s time interval. RESULTS The collected data show that a wide submerged area of 350 km2, between 400 to 1200 m depths is undergoing slow-moving deformation and associated secondary mass wasting phenomena. Morphological features include trenches, counterscarps, bulging and both extensional and contractional features while internal deformations show typical landward dipping reflectors with strong evidence of synsedimentary faulting and asymmetric anticlines. Deformation processes operate at various scales generating folds with wavelength ranging from hundreds meters to kilometers. Extensional and rotational rupture surfaces sole out at various low-angle detachment planes located at depths from few hundred meters to 1 kilometer in subsurface. The internal organization of the failing mass shows different pattern of deformation that allows the identification of three main units: 1) a basal unit consisting of a very broad, asymmetric slump fold with a wavelength of about 5 km and amplitude of some 100 m. The fold axis is not vertical and the three dimensional interpretation indicates that the structure is not cylindrical. The fold strictly correlates with a morphological bulge seen on bathymetry at about 20 km south of Ischia Island. 2) A wedge shaped intermediate unit characterized by discontinuous and folded reflectors, locally showing basal detachment planes and compressional features. 3) A surficial slump unit affecting the upper and middle slope characterized by a basal decollément surface and normal growth faults that sole out at depths ranging from 70 to 40 m in subsurface. It is still unclear whether the landslide process can be favored by the volcano-tectonic evolution and rapid vertical accretion of Ischia volcano or is solely due to possibly volcanic spreading of the Ischia Island. REFERENCES CHIOCCI, F. L. & DE ALTERIIS, G. (2006) - The Ischia debris avalanche. First, clear submarine evidence in the Mediterranean of a volcanic island pre-historic collapse. Terra Nova, 18, 202–209. DE ALTERIIS, G., INSINGA D. ET AL. (2010) - Age of submarine debris avalanches and tephrostratigraphy offshore Ischia Island, Tyrrhenian Sea, Italy. Marine Geology 278 (2010) 1– 18. DE ALTERIIS, G. & VIOLANTE, C. (2009) - Catastrophic landslides off Ischia volcanic island (Italy) during prehistory. In: C. Violante, (ed.) Geohazard in Rocky Coastal Areas. Geological Society, London, Special Publications, 322, 73– 104. VEZZOLI, L. (1988) Island of Ischia. Quaderni de ‘La Ricerca Scientifica’ Progetto finalizzato ‘Geodinamica’, CNR Monografie finali, 10. VIOLANTE, C., BUDILLON, F., ET AL. (2004) - Submerged hummocky topographies and relations with landslides on the northwestern flank of Ischia island, southern Italy. In: ‘Occurrence and mechanisms of flow-like landslides in natural slopes and earthfills’, Sorrento, 14–16 May 2003. AGI, 2, 309–315

Eradication of Candida albicans persister cell biofilm by the membranotropic peptide gH625

Biofilm formation poses an important clinical trouble due to resistance to antimicrobial agents; therefore, there is an urgent demand for new antibiofilm strategies that focus on the use of alternative compounds also in combination with conventional drugs. Drug-tolerant persisters are present in Candida albicans biofilms and are detected following treatment with high doses of amphotericin B. In this study, persisters were found in biofilms treated with amphotericin B of two clinical isolate strains, and were capable to form a new biofilm in situ. We investigated the possibility of eradicating persister-derived biofilms from these two Candida albicans strains, using the peptide gH625 analogue (gH625-M). Confocal microscopy studies allowed us to characterize the persister-derived biofilm and understand the mechanism of interaction of gH625-M with the biofilm. These findings confirm that persisters may be responsible for Candida biofilm survival, and prove that gH625-M was very effective in eradicating persister-derived biofilms both alone and in combination with conventional antifungals, mainly strengthening the antibiofilm activity of fluconazole and 5-flucytosine. Our strategy advances our insights into the development of effective antibiofilm therapeutic approaches

Gelatin immobilized growing yeast cells: changes in the glycosylation level of external invertase and cell wall composition

Free and gelatin immobilized yeast cells from two different strains were analyzed by means of SDS-PAGE as regards: i) the glycosylation levels of external invertase before and after treatment with endo-beta-N-acetylglycosaminidase (Endo H), ii) the pattern of mannoproteins released from the cell wall after extraction with SDS, beta-mercaptoethanol and Zymoliase digestion. The results obtain suggest that the composition and structure of the cell wall is modified when cell growth takes place in the state of immobilization

Magnetic Anomalies of the Tyrrhenian Sea Revisited: A Processing Workflow for Enhancing the Resolution of Aeromagnetic Data

We propose a processing workflow to enhance the information content of aeromagnetic data. Our workflow is based on the downward continuation and subsequent L-transform of magnetic data. This workflow returns a map showing single highs, which correspond to the location of magnetic bodies, and does not need any a priori information about the source magnetization. We validated our workflow using the aeromagnetic anomalies of the Tyrrhenian Sea (Italy), by a comparison of the reprocessed aeromagnetic anomalies with high-resolution shipborne magnetic data in three selected areas. Through this comparison, we show that the proposed processing workflow of aeromagnetic data leads to more accurate interpretative results. Our results indicate that, in areas where higher resolution data are lacking, the reprocessing of aeromagnetic data according to our workflow may be as decisive as to suggest changes to their previous interpretations or, at least, useful for highlighting areas of special interest, deserving to be magnetically explored by a dedicated high-resolution shipborne survey

NOVEL STRATEGY TO PRODUCE NON-SPHERICAL POLYMERIC MICROPARTICLES FOR DRUG DELIVERY AND TISSUE ENGINEERING

The aim of this study was to develop a general method to produce polymeric particles of non-spherical shape and encapsulating labile biomolecules starting from previously fabricated spherical particles, suitable for applications in the field of drug delivery and tissue engineering. The main concern was not only to preserve the biological activity of such molecules during the production process, but also to provide elaborate particles which could release bioactive moieties over a long time span. To date, this demanding task is only addressed by particles which are spherical in shape. For instance, current protein encapsulation technologies of polymeric microspheres have been optimized for effectively protect their "protein cargo" from inactivation occurring in biological environments, preserving its bioactivity during release up to several weeks. Nevertheless, the scenario of drug delivery and tissue engineering would be greatly expanded by strategies that enable the production of particles both with complex shape and with the beneficial properties of spherical particles. Therefore, as a proof of principle, it is has been developed an easy and effective stamp-based method to produce poly-lactic-glycolic-acid (PLGA) microparticles encapsulating Vascular Endothelial Growth Factor (VEGF), with different shapes. It has been demonstrated that PLGA microspheres can be deformed at room temperature exploiting solvent/non-solvent plasticization. To predict the depression of the glass transition temperature of the polymer due to solvent sorption, a thermodynamic model and measurements with a quartz crystal microbalance were employed. Since the properties of the starting microspheres are not altered by the process conditions, this gentle method allows to produce shaped particles which provide a prolonged release of VEGF in active form, as verified by an angiogenic assay. The retention of the biological activity of an extremely labile molecule, i.e. VEGF, let us to hypothesize that a wide variety of drugs and proteins encapsulated in thermoplastic polymers can be processed with this method. It was also demonstrated that this method allows to produce shaped and porous microparticles made of gelatin, which are of great interest in the field of tissue engineering. Furthermore, needle-shaped microparticles for transdermal drug delivery, and sintered microparticles have been produced

Rhodanese-BSA polymers entrapped in insolubilised gelatin gels: properties and behaviour in continuous systems

The enzymatic oxidation of cephalosporin C to glutaryl-7-amminocephalosporanic acid (glutaryl-7-ACA) was carried out utilizing permeabilized whole cells of the yeast Trigonopsis variabilis entrapped in Ca-alginate beads. The biomass, cultured in a rich medium containing D,L methionine and harvested after 72 h of growth, exhibited high levels of D-aminoacid oxidase activity. Prior to use, thewho,lke cells were permeabilized with four freeze-thawing cycles and immobilized in polysaccharide matrices, such as Ca-alginate and K- carrageenan, and in an insolubilised gelatin gel. The best results in terms of activity yield and storage stability were obtained with cells entrapped in Ca-alginate beads. These cells were utilized for glutaryl-7-ACA production in a continuous stirred batch reactor (CSTR) and in a packed bed reactor working in a plug flow reactor (PFR), using 50 mm Cephalosporin C as substrate. The performances of the two systems were compared. The overall on a void volume basis) were 1.63 g and 255 mg of glutaryl-7-ACA h-1 in the PFR and in CSTR, respectively

A general kinetic and mass transfer model to simulate the baker's yeast growth in bioreactors

In this paper a general cybernetic model has been developed to describe the growth of baker's yeast in every type of reactor (batch, fed-batch, continuous). The model, which takes into account also the mass-transfer oxygen limitation, has been tested on literature continuous runs performed at different aerating gas composition. The results obtained show that the model can describe the growth of S. cerevisiae also under conditions of inefficient aeration, so it should be useful to optimise and modeling industrial bioreactors

Immobilization of Saccharomyces cerevisiae cells by adhesion to polymeric matrices obtained by radiation-induced polymerization

An immobilization method based on the spontaneous adhesion of invertase-active cells of yeast (Saccharomyces cerevisiae) to tuff granules was described by Parascandola, Scardi, and Tartaglione. Compared with gel entrapment, immobilization by adhesion is much more simple and free from diffusional limitations. However, adhesion is a rather complicated process involving surface interactions between microbial cells and the so-called substratum, that is, the solid support to which they attach. Because there are still many unanswered questions about the mechanism of adhesion, the selection of suitable substrata for a given microbial species can be made only empirically. Thus, to find substrata better than tuff or insolubilized gelatin, polymeric hydrogels that were obtained by radiation-induced polymerization below 0 °C and that were employed successfully for immobilizing enzymes, cells and antibodies were considered. A dozen of such polymer matrices with different hydrophilicities were synthesized and assayed as possible substrata for S. cereviisae cells used in continuous ethanol production

Effect of auxotrophies on yeast performance in aerated fed-batch reactor

A systematic investigation on the effects of auxotrophies on the performance of yeast in aerated fed-batch reactor was carried out. Six isogenic strains from the CEN.PK family of Saccharomyces cerevisiae,one prototroph and five auxotrophs, were grown in aerated fed-batch reactor using the same operative conditions and a proper nutritional supplementation. The performance of the strains, in terms of final biomass decreased with increasing the number of auxotrophies. Auxotrophy for leucine exerted a profound negative effect on the performance of the strains. Accumulation of reactive oxygen species (ROS) in the cells of the strain carrying four auxotrophies and its significant viability loss, were indicative of an oxidative stress response induced by exposure of cells to the environmental conditions. The mathematical model was fundamental to highlight how the carbon flux, depending on the number and type of auxotrophies, was diverted towards the production of increasingly large quantities of energy for maintenance