Oceanographic signals at the Benthic Boundary Layer in the Mediterranean Sea

The Benthic Boundary Layer (BBL) is considered a quite homogeneous environment where a wide variety of processes (chemical, physical, geological and biological) occur often producing front structures or inducing turbulence phenomena. The typical stratification of these zones can be interrupted by episodic events which effects can diffuse to the ocean interior exploiting by local current and mixing processes. According to hydrodynamic definition, the BBL thickness may vary from few millimetres up to 100 metres depending on the friction intensity with the sea bed and the stability of water column above it. Generally in deep-sea condition, the BBL thickness is defined by the ratio between the friction velocity and the Coriolis parameter according to the Ekman scale. In the latest years several experiments have been carried out in the deep water of Mediterranean Sea, focusing on the survey and study of benthic processes following a multidisciplinary approach. Benthic observatories, such as SN-1 and GEOSTAR, allow to record long time-series of geochemical, seismological, geomagnetic, geodetic and oceanographic data and allow to understand the dynamics and evolution of the processes though comparison and interpolation of different types of signals. From a oceanographic point of view, the technology of these benthic observatories brings the possibility to observe and measure directly the hydrological properties at the seafloor collecting data for long-time series and with high sampling rate. The observatories deployed in Mediterranean Sea, have provided good information about variations and oscillations of hydrological parameters in deep water where the monitoring is almost lacking. In some cases it has been possible to link these deep-sea datasets with upper data collected by ship-handled system during the same period or during different cruises. This allows to have a more complete idea of the linkage between surface, intermediate and bottom sea. Hence the multidisciplinary approach represents a very important aspect for this kind of study, because it allows not only a cross check of functionality among all the instruments but also an important tool to recognise and better understand possible nonphysical- oceanographic phenomena

Noninvasive evaluation of coronary artery stents patency after PTCA: role of Multislice Computed Tomography.

Restenosis of a coronary artery treated with stent implantation is a well-known process that can compromise over time the success of a coronary angioplasty and, accordingly, treated patients must undergo periodic controls. We have recently witnessed a shift towards a greater use of Multi-slice CT (msCT) in the study of coronary disease without its precise indications and limits having yet been underlined. The purpose of our study is to assess the role of msCT in the follow-up of patients treated with coronary angioplasty.Forty-eight patients, for a total of 72 lesions, who underwent treatment with a slotted tube stent implant, had an msCT examination 1 week before scheduled coronary angiography, and the results were compared. 34 stents/72 (47.2\%) were inserted on the left anterior descending; 21/72 (29.2\%) on the right coronary; 17/72 (23.6\%) on the circumflex artery or obtuse marginal branches.The observation of the opacification of the vessel located distally to treated segments allowed us to assess the patency of all stents. Coronary angiography identified a significant intrastent restenosis or a stent occlusion in 12 of the 72 stents analysed (16.7\%). msCT enabled easier visualization of the lumen of the treated artery and its differentiation from the stent struts in the ones located on the left anterior descending artery than those on the circumflex (28 stents out of 34 [82.4\%] vs 13/17 [76.5\%]; p3.5 mm (OR 2.97 [IC 95\%: from 1.67 to 4.86]; p<0.01).The msCT technology available at present makes the study of smaller stents and those positioned on the right coronary artery and circumflex rather complex; on the other hand msCT appears a promising study method for stents greater then 3.5 mm and for those positioned on the proximal segment of the left anterior descending artery

A new active volcano in the Tyrrhenian Sea?

A strong earthquake occurred in 2002 offshore from the northern coast of Sicily in the Southern Tyrrhenian Sea (Italy), and was followed by a series of hundreds of aftershocks. Communications through the fibre-optic cable between Palermo and Rome were interrupted a few hours after the occurrence of the main shock. After the required technical checks, the failure point was found a few kilometres away from the seismic sequence area. A few days later, a specialised cable ship reached the failure area. One side of the cable was completely burnt, while about three kilometres of cable was found locked. Tests on slices of cable showed that the temperature at which the cable was heated went well above 700oC. We can speculate that the earthquakes triggered off the emission of a submarine lava flow that buried, trapped and burnt the fibre-optic cable. The revising of the bathymetric survey made before the cable’s deployment allowed for the identification of a seamount in the vicinity of the rupture. This structure could represent the lava flow’s source volcano

Foreland deformational pattern in the Southern Adriatic Sea

Two major deformation belts occur in the portion of the Adriatic Sea offshore the Gargano Promontory. Although these two belts display similar characters on seismic profiles, they are different in other respects. The NE-SWtrending Tremiti Deformation Belt, located north of the Gargano Promontory, originated during the Plio-Quaternary, while the E-W-trending South Gargano Deformation Belt, located south of the Gargano Promontory, formed in a time span that goes from Eocene to early Pliocene. On the ground of structural and stratigrafic evidence these deformation belts are interpreted as originated by tectonic inversion of Mesozoic extensional faults. This inversion tectonics, of Tertiary age, can be related to the evolution of the fold-and-thrust belts that surround the Adriatic Sea. A moderate seismic activity, recorded around the Tremiti Island, and historical seismological data suggest that the whole of study area is, at present, seismically active. Therefore, this portion of the Adriatic block still represents a preferental site of deformation

The Benthic Boundary Layer: geochemical and oceanographic data from the GEOSTAR-2 observatory

Geochemical and oceanographic data, acquired throughout 6 months by the GEOSTAR-2 benthic observatory in southern Tyrrhenian Sea, evidenced ocean-lithosphere interactions in the 1900-m deep Benthic Boundary Layer (BBL), distinguishing two water masses with different origin and, possibly, benthic residence time. Gas concentration, helium isotopic ratios, radioactivity, temperature, salinity and vertical component of the current converged towards the indication of a BBL characterised by a colder and fresher western water (WW), which is episodically displaced by the cascading of the warmer and saltier Eastern Overflow Water (EOW). The benthic WW has higher concentration of geochemical tracers diffusing from the seafloor sediments. The data set shows the potential of long-term, continuous and multiparametric monitoring in providing unique information which cannot be acquired by traditional, short-term or single-sensor investigations

Foreland tectonics in the southern Adriatic Sea

Two major deformation belts occur in the portion of the Adriatic Sea offshore the Gargano Promontory. The NE-SW - trending Tremiti Deformation Belt, located north of the Gargano Promontory, originated during the Plio- Quaternary, while the E-W-trending South Gargano Deformation Belt, located south of the Gargano Promontory, formed in a time span from Eocene to Early Pliocene. These deformation belts may have originated by tectonic inversion of Mesozoic extensional faults. This inversion tectonics, of Tertiary age, can be related to the evolution of the fold-and thrust belts surrounding the Adriatic Sea. The whole of the study area is, at present, seismically active and represents a preferential site of deformation

Stromboli: a natural laboratory of environmental science

The science of environment is per se multi- and inter-disciplinary. It is not possible to separate the role of the physical, chemical, biological, and anthropic factors, respectively. Research must therefore rely on suitable natural laboratories, where all different effects can be simultaneously monitored and investigated. Stromboli is a volcanic island slightly North of Sicily, within a tectonic setting characterised by a Benioff zone, curved like a Greek theatre, opened towards the Tyrrhenian Sea, with deep earthquakes. Moreover, it is a unique volcano in the world in that since at least ~ 3000 years ago, it has exploded very regularly, about every 15^20 min. Hence, it is possible to monitor statistically phenomena occurring prior, during, and after every explosion. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) has recently established a permanent Laboratory and an extensive interdisciplinary programme is being planned. A few main classes of items are to be considered including: (1) matter exchange (solid, liquid, gas, chemistry); (2) thermal and/or radiative coupling; (3) electromagnetic coupling; (4) deformation; (5) biospheric implications; and (6) anthropic relations since either the times of the Neolithic Revolution. Such an entire multidisciplinary perspective is discussed, being much beyond a mere volcanological concern. We present here the great heuristic potential of such a unique facility, much like a natural laboratory devoted to the investigation of the environment and climate.Published429-442JCR Journalreserve

Leishmania infantum and Leishmania braziliensis : differences and similarities to evade the innate immune system

Visceral leishmaniasis is a severe form of the disease, caused by Leishmania infantum in the New World. Patients present an anergic immune response that favors parasite establishment and spreading through tissues like bone marrow and liver. On the other hand, Leishmania braziliensis causes localized cutaneous lesions, which can be self-healing in some individuals. Interactions between host and parasite are essential to understand disease pathogenesis and progression. In this context, dendritic cells (DCs) act as essential bridges that connect innate and adaptive immune responses. In this way, the aim of this study was to compare the effects of these two Leishmania species, in some aspects of human DCs’ biology for better understanding of the evasion mechanisms of Leishmania from host innate immune response. To do so, DCs were obtained from monocytes from whole peripheral blood of healthy volunteer donors and from those infected with L. infantum or L. braziliensis for 24 h. We observed similar rates of infection (around 40%) as well as parasite burden for both Leishmania species. Concerning surface molecules, we observed that both parasites induced CD86 expres-sion when DCs were infected for 24 h. On the other hand, we detected a lower surface expression of CD209 in the presence of both L. braziliensis and L. infantum, but only the last one promoted the survival of DCs after 24 h. Therefore, DCs infected by both Leishmania species showed a higher expression of CD86 and a decrease of CD209 expression, suggesting that both enter DCs through CD209 molecule. However, only L. infantum had the ability to inhibit DC apoptotic death, as an evasion mechanism that enables its spreading to organs like bone marrow and liver. Lastly, L. braziliensis was more silent parasite, once it did not inhibit DC apoptosis in our in vitro model

Monitoring of a methane-seeping pockmark by cabled benthic observatory (Patras Gulf, Greece)

A new seafloor observatory, the gas monitoring module (GMM), has been developed for continuous and long-term measurements of methane and hydrogen sulphide concentrations in seawater, integrated with temperature (T), pressure (P) and conductivity data at the seafloor. GMM was deployed in April 2004 within an active gas-bearing pockmark in the Gulf of Patras (Greece), at a water depth of 42 m. Through a submarine cable linked to an onshore station, it was possible to remotely check, via direct phone connection, GMM functioning and to receive data in nearreal time. Recordings were carried out in two consecutive campaigns over the periods April–July 2004, and September 2004–January 2005, amounting to a combined dataset of ca. 6.5 months. This represents the first long-term monitoring ever done on gas leakage from pockmarks by means of CH4+H2S+T+P sensors. The results show frequent T and P drops associated with gas peaks, more than 60 events in 6.5 months, likely due to intermittent, pulsation-like seepage. Decreases in temperature in the order of 0.1–1°C (up to 1.7°C) below an ambient T of ca. 17°C (annual average) were associated with short-lived pulses (10–60 min) of increased CH4+H2S concentrations. This seepage “pulsation” can either be an active process driven by pressure build-up in the pockmark sediments, or a passive fluid release due to hydrostatic pressure drops induced by bottom currents cascading into the pockmark depression. Redundancy and comparison of data from different sensors were fundamental to interpret subtle proxy signals of temperature and pressure which would not be understood using only one sensor.Published297-302JCR Journalreserve

Observing Volcanoes from the Seafloor in the Central Mediterranean Area

The three volcanoes that are the object of this paper show different types of activity that are representative of the large variety of volcanism present in the Central Mediterranean area. Etna and Stromboli are sub-aerial volcanoes, with significant part of their structure under the sea, while the Marsili Seamount is submerged, and its activity is still open to debate. The study of these volcanoes can benefit from multi-parametric observations from the seafloor. Each volcano was studied with a different kind of observation system. Stromboli seismic recordings are acquired by means of a single Ocean Bottom Seismometer (OBS). From these data, it was possible to identify two different magma chambers at different depths. At Marsili Seamount, gravimetric and seismic signals are recorded by a battery-powered multi-disciplinary observatory (GEOSTAR). Gravimetric variations and seismic Short Duration Events (SDE) confirm the presence of hydrothermal activity. At the Etna observation site, seismic signals, water pressure, magnetic field and acoustic echo intensity are acquired in real-time thanks to a cabled multi-disciplinary observatory (NEMO-SN1 ). This observatory is one of the operative nodes of the European Multidisciplinary Seafloor and water-column Observatory (EMSO; www.emso-eu.org) research infrastructure. Through a multidisciplinary approach, we speculate about deep Etna sources and follow some significant events, such as volcanic ash diffusion in the seawater