Searching for a new model of governance in the high seas: Game theory applied to international commons management

In the last decade, the United Nations took important steps for the creation of a new instrument for biodiversity protection in areas beyond national jurisdiction. This put under discussion the central issues of international commons management and of the governance model for the High Seas. The aim of this paper is to discuss and evaluate critically the political negotiations already made and yet to come, as well as their rationale. For this purpose, the paper applies game theory to fisheries management to get insights. This research aims to contribute toward more qualified and grounded decisions. The key role of cooperation in the sustainable use of common resources is stressed.info:eu-repo/semantics/publishedVersio

Nano-hydroxyapatite in oral care cosmetics: characterization and cytotoxicity assessment

Nano-hydroxyapatite has been used as an oral care ingredient, being incorporated in several products for the treatment of dental hypersensitivity and enamel remineralisation. Despite its promising results, regulatory and safety concerns have been discussed and questioned by the European Scientific Committee on Consumer Safety (SCCS) regarding the usage of hydroxyapatite nanoparticles in oral care products. In this work, a commercially available nano-hydroxyapatite was characterized and its cytocompatibility towards human gingival fibroblasts was evaluated, as well as its irritation potential using the in vitro HET-CAM assay. All the conditions chosen in this study tried to simulate the tooth brushing procedure and the hydroxyapatite nanoparticles levels normally incorporated in oral care products. The commercial hydroxyapatite nanoparticles used in this study exhibited a rod-like morphology and the expected chemical and phase composition. The set of in vitro cytotoxicity parameters accessed showed that these nanoparticles are highly cytocompatible towards human gingival fibroblasts. Additionally, these nanoparticles did not possess any irritation potential on HET-CAM assay. This study clarifies the issues raised by SCCS and it concludes that this specific nano-hydroxyapatite is cytocompatible, as these nanoparticles did not alter the normal behaviour of the cells. Therefore, they are safe to be used in oral care products.The authors acknowledge the support of the Biointerfaces and Nanotechnology i3S Scientific Platform, as well as Luís Teixeira and Marta Ferro from University of Aveiro for the characterization of the HA-NP with TEM. Financial support from the European Union (FEDER funds POCI/01/0145/FEDER/007265) and National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministério da Educação e Ciência) under the Partnership Agreement PT2020 UID/QUI/50006/2019 is acknowledged

Terahertz array beamforming using low-voltage graphene-modulators

The terahertz band (0.1-10 THz) is a vastly un-used segment of the spectrum, set to be used by future 6G communications, for its super high transmission speeds. Not only that, but radiation in the below infra-red band is also finding more uses in various applications, such as sensing and medical, where THz may enable innovative solutions. However, technology for this part of the spectrum is still in its infant stages of development. From emitters, to re-ceivers, signal generators, antennas, the devices aren’t yet matured or even realized. In this work we present a 4x2 antenna array, whose diagram is controlled via graphene modulators, designed having in mind a fabrication process available for 8 inch wafers. Chemical potentials of 0.1 to 0.4 eV are used, which corresponds to maximum bias tensions of 5 V, that should be more easily implemented with conventional electronics. This allows a comprehensive dia-gram control, reaching 360 degrees of reach in Phi, and at least 15 degrees in theta (Figure 1). Theoretically, a plasmonic array with graphene modulators could use graphene radiators to achieve incredible size reduction. In practice, graphene will not have enough efficiency to serve as a useful radiator, and metallic radiators should serve as the main emitting elements (Figure 2). This means a compromise between array dimensions and radiation efficiency, as the metallic elements do not support the plas-monic phenomenon at 1 THz. Additionally, graphene on-chip electronics implementation in the micro and nanometer range presents sev-eral other challenges. Adding additional gra-phene elements besides the modulators may also not be feasible with current available fabri-cation processes and measuring capabilities, or even in a functional sense. Some planned-for-fabrication devices are pre-sented. Their architecture was designed to facil-itate measurements in probe-less THz meas-urement ranges. The fabrication masks are ready, and the devices should be relatively sim-ple to fabricate

Buried dislocation networks designed to organize the growth of III-V semiconductor nanostructures

We first report a detailed transmission electron microscopy study of dislocation networks (DNs) formed at shallowly buried interfaces obtained by bonding two GaAs crystals between which we establish in a controlled manner a twist and a tilt around a k110l direction. For large enough twists, the DN consists of a twodimensional network of screw dislocations accommodating mainly the twist and of a one-dimensional network of mixed dislocations accommodating mainly the tilt. We show that in addition the mixed dislocations accommodate part of the twist and we observe and explain slight unexpected disorientations of the screw dislocations with respect to the k110l directions. By performing a quantitative analysis of the whole DN, we propose a coherent interpretation of these observations which also provides data inaccessible by direct experiments. When the twist is small enough, one screw subnetwork vanishes. The surface strain field induced by such DNs has been used to pilot the lateral ordering of GaAs and InGaAs nanostructures during metal-organic vapor phase epitaxy. We prove that the dimensions and orientations of the nanostructures are correlated with those of the cells of the underlying DN and explain how the interface dislocation structure governs the formation of the nanostructures

<i>Schistosoma mansoni</i> cercariae experience influx of macromolecules during skin penetration

We have observed that when cercariae penetrate the skin of mice, there is influx into their tissues of Lucifer Yellow and certain labelled molecules of up to 20 kDa molecular weight. This observation was made using a variety of fluorescent membrane-impermeant compounds injected into the skin before the application of cercariae. This unexpected phenomenon was investigated further by transforming cercariae in vitro in the presence of the membrane-impermeant compounds and examining the distribution by microscopy. In schistosomula derived from this procedure, the nephridiopore and surface membrane were labelled while the pre- and post-acetabular glands were not labelled. The region associated with the oesophagus within the pharyngeal muscle clearly contained the fluorescent molecules, as did the region adjacent to the excretory tubules and the germinal mass. We used cercariae stained with carmine to aid identification of regions labelled with Lucifer Yellow. Although the mechanism of this influx is unclear, the observation is significant. From it, we can suggest an hypothesis that, during skin penetration, exposure of internal tissues of the parasite to external macromolecules represents a novel host-parasite interfac