247 research outputs found
Delayed differential equation based study of sub-terahertz emission in multi-section quantum dot ring lasers
No full textWe present a study of the generation of subterahertz pulses in multi-section quantum dot (QD) ring lasers based on an improved version of the well-established delayed differential equation model, and taking into account an arbitrary number of gain and absorber sections. Results of the analysis of an 8-section ring laser emitting at 1.3 μm are presented. The proposed approach provides a significant insight for the understanding of the onset of the harmonic mode-locking in this family of devices and shows to be an effective tool for the optimization of the real devices in terms of pulses quality and generated RF intensity
A review of the classification systems for marine benthic habitats and the new updated Barcelona Convention classification for the Mediterranean
No full textThe Mediterranean Sea supports high levels of biodiversity and complexity but is facing increasing human pressures, so that strategies to protect and recover its ecosystems must be a priority in environmental policies. Benthic cartography represents the first step of marine spatial planning for the proper management and protection of our sea. Univocal habitat classification systems are thus needed to map, monitor, and inventory marine habitats, and to guarantee common and shared frames for a harmonized interpretation of the Mediterranean habitat types. In this paper we reviewed the existing classification systems of marine benthic habitats, to discuss the process of revision and updating of one of the first system developed under the Barcelona Convention (BC) in 1998 and adopted by all the Mediterranean countries. The BC classification was revised including the new habitats discovered in the last 30 years, and consistently with the criteria used to revise the EUropean Nature Information System (EUNIS), which is a comprehensive pan-European system for habitat identification. The updated BC classification is hierarchical with 5 levels, which allows representing the most suitable habitat level with respect to the restitution scale of the map. Each habitat is univocally identified by an alpha-numeric code, name and general description following the bionomic approach traditionally adopted in the Mediterranean benthic cartography since the late nineteen century. The new BC classification lists 128 main habitats up to the level 4, which may also contain sub-habitats at the level 5, i.e. associations and facies, totalising 394 habitat types (54% of new habitats with respect to the first BC classification). The updated BC classification system has been used for the selection of reference marine habitats that support two fundamental processes of environmental management: i) identification of Specially Marine Protected Areas according to the SPA/BD Protocol of Barcelona Convention; ii) selection of habitats to be monitored, as requested by the Integrated Monitoring and Assessment Programme and the European Directives (e.g., Water Framework and Marine Strategy). The new list of reference habitats, selected because of their high ecological and conservation value, contains 267 habitats, corresponding to 68% of the total habitats listed in the updated BC classification
Depth and substrate type driven patterns in the infralittoral fish assemblage of the NW Mediterranean Sea
No full textA miniaturized hydrogel-based in vitro model for dynamic culturing of human cells overexpressing beta-amyloid precursor protein
No full textRecent findings have highlighted an interconnection between intestinal microbiota and the brain, referred to as microbiota–gut–brain axis, and suggested that alterations in microbiota composition might affect brain functioning,
also in Alzheimer’s disease. To investigate microbiota–gut–brain axis biochemical pathways, in this work we developed
an innovative device to be used as modular unit in an engineered multi-organ-on-a-chip platform recapitulating in vitro
the main players of the microbiota–gut–brain axis, and an innovative three-dimensional model of brain cells based
on collagen/hyaluronic acid or collagen/poly(ethylene glycol) semi-interpenetrating polymer networks and β-amyloid
precursor protein-Swedish mutant-expressing H4 cells, to simulate the pathological scenario of Alzheimer’s disease.
We set up the culturing conditions, assessed cell response, scaled down the three-dimensional models to be hosted
in the organ-on-a-chip device, and cultured them both in static and in dynamic conditions. The results suggest that the
device and three-dimensional models are exploitable for advanced engineered models representing brain features also
in Alzheimer’s disease scenario
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