Marine litter is any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment. Ingestion of marine litter can have lethal and ...sub-lethal effects on wildlife that accidentally ingests it, and sea turtles are particularly susceptible to this threat. The European Commission drafted the 2008/56/EC Marine Strategy Framework Directive with the aim to achieve a Good Environmental Status (GES), and the loggerhead sea turtle (Caretta caretta, Linnaeus 1758) was selected for monitoring the amount and composition of litter ingested by marine animals. An analogous decision has been made under the UNEP/MAP Barcelona Convention for the protection of the Mediterranean Sea, following the Ecosystem Approach. This work provides for the first time, two possible scenarios for the Marine Strategy Framework Directive GES, both related to “Trends in the amount and composition of litter ingested by marine animals” in the Mediterranean Sea. The study validates the use of the loggerhead turtle as target indicator for monitoring the impact of litter on marine biota and calls for immediate use of this protocol throughout the Mediterranean basin and European Region. Both GES scenarios are relevant worldwide, where sea turtles and marine litter are present, for measuring the impact of ingested plastics and developing policy strategies to reduce it. In the period between 2011 and 2014, 150 loggerhead sea turtles, found dead, were collected from the Italian Coast, West Mediterranean Sea Sub-Region. The presence of marine litter was investigated using a standardized protocol for necropsies and lab analysis. The collected items were subdivided into 4 main categories, namely, IND-Industrial plastic, USE-User plastic, RUB-Non plastic rubbish, POL-Pollutants and 14 sub-categories, to detect local diversity. Eighty-five percent of the individuals considered (n = 120) were found to have ingested an average of 1.3 ± 0.2 g of litter (dry mass) or 16 ± 3 items.
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•Interaction between marine litter and sea turtles: relevant worldwide scenarios were examined to measure the impact of ingested plastics and to develop policy strategies to reduce it.•GES and Target scenarios relating to “Trends in the amount and composition of litter ingested by marine animals” in the Mediterranean Sea were established.•The Loggerhead is confirmed to be the main target species for litter ingested by marine animals in European and Non-EU Mediterranean Countries.
This paper presents new scenarios relating to “Trends in the amount and composition of litter ingested by marine animals” in the Mediterranean Sea. It is the result of a pilot study on the use of the loggerhead turtle, Caretta caretta as indicator species under the Marine Strategy Framework Directive and the Barcelona Convention for the achievement of Good Environmental Status.
A trace fossil assemblage from the Silurian (Llandovery) black shales of the Genna Muxerru Formation is reported for the first time. The ichnofossil record is abundant, well-preserved and comprises ...Alcyonidiopsis, Cochlichnus, Phymatoderma, Planolites (large morphotype), Planolites (rough morphotype) and a ‘Small chondritid’. Sedimentological and ichnological evidence indicates that the bioturbated black shales were deposited in outer shelf (or deeper) settings with severe depletion in oxygen. The seafloor provided a high food supply for the infauna. The palaeoenvironment of the Genna Muxerru Formation is an ancient analogue of modern oxygen-minimum zones. Burrow fills are apparently massive in macroscopic view, whereas observations under the petrographic and stereoscopic microscope show that a lifestyle dominated, i.e. that of pellet-filling sediment-feeders. As such, the Genna Muxerru Formation provides not only a new ethologic reference for low-oxygen settings but also a methodological benchmark for ichnological analysis of black shales. Bioturbation in black shales may be commoner than expected but its recognition requires microscopic observation.
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•An abundant ichnofauna is preserved in the Silurian Genna Muxerru Formation.•Tracemakers colonized outer shelf settings which were severely depleted in oxygen.•The dominant lifestyle was that of pellet-filling sediment-feeders.•Microscope observations are essential to detect trace fossils in black shales.•Bioturbated black shales may be commoner than traditionally expected.
Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous ...experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors.
After tooth extraction, a modeling and remodeling phase of bone and soft tissues occurs. It has been fully demonstrated that bone resorption as high as 50% can take place regarding ridge width and a ...variable amount concerning ridge height, making it difficult to perform implant surgery.
Active members of the Italian Academy of Osseointegration (IAO) participated in this Consensus Conference, and three systematic reviews were conducted before the meeting to provide guidelines on alveolar ridge preservation procedures. The systematic reviews covered the following topics: (1) What material best preserves the dimensions of the ridge horizontally and vertically?; (2) what material favors the formation of the highest quantity of new bone?; (3) which technique would best seal the socket?; and (4) what effect does alveolar ridge preservation have on soft tissues?
The main conclusions reached by the assembly were that alveolar ridge preservation is advisable after dental extraction, particularly in esthetic areas, in proximity of anatomical structures (ie, maxillary sinus, inferior alveolar nerve, and mental foramen), whenever the treatment plan requires delayed placement, and whenever patients ask to postpone implant insertion for various reasons. Socket debridement is advised before the use of a "regenerative material," and xenograft is considered the gold standard material to maintain ridge dimensions. Another indication is antibiotic therapy, which is recommended in the case of alveolar ridge preservation (amoxicillin 2 g 1 hour before the intervention and 1 g every 12 hours for 6 days). A membrane or autologous soft tissue should be used to seal the socket and protect the regenerative material, and the indicated reentry time (implant insertion) is 4 to 6 months.
This Consensus Conference agreed that the adoption of alveolar ridge preservation can effectively prevent physiologic bone loss, especially in esthetic areas. It is recommended to cover the xenograft material with a membrane or autologous soft tissue, and antibiotic therapy is advisable.
Chirping Alfv\'{e}n modes are considered as potentially harmful in burning
Tokamak plasmas. In this paper, the nonlinear evolution of a
single-toroidal-number chirping mode is analysed by numerical ...particle
simulation. This analysis can be simplified if the different resonant
phase-space structures can be investigated as isolated ones. This can be done
adopting a coordinate system that includes two constants of motion. In our
simulations, we adopt as constants of motion, the magnetic momentum and the
initial particle coordinates. For each resonant structure, a density-flattening
region is formed around the respective resonance radius, with radial width that
increases as the mode amplitude grows. It is delimited by two large negative
density gradients, drifting inward and outward. With constant mode frequency,
this density flattening would be responsible for the exhausting of the drive
when large negative density gradients leave the resonance region. The frequency
chirping, however, causes the resonance radius and the resonance region to
drift inward. This drift delays the moment in which the inner density gradient
reaches the inner boundary of the resonance region. On the other side, the
island reconstitutes around the new resonance radius; as a consequence, the
large negative density gradient further moves inward. This process continues as
long as it allows to keep the large gradient within the resonance region. When
this is no longer possible, the resonant structure ceases to be effective in
driving the mode. To further grow, the mode has to tap a different resonant
structure, possibly making use of additional frequency variations.
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