A reverse KAM method to estimate unknown mutual inclinations in exoplanetary systems

The inclinations of exoplanets detected via radial velocity method are essentially unknown. We aim to provide estimations of the ranges of mutual inclinations that are compatible with the long-term stability of the system. Focusing on the skeleton of an extrasolar system, i.e., considering only the two most massive planets, we study the Hamiltonian of the three-body problem after the reduction of the angular momentum. Such a Hamiltonian is expanded both in Poincar\'e canonical variables and in the small parameter $D_2$, which represents the normalised Angular Momentum Deficit. The value of the mutual inclination is deduced from $D_2$ and, thanks to the use of interval arithmetic, we are able to consider open sets of initial conditions instead of single values. Looking at the convergence radius of the Kolmogorov normal form, we develop a reverse KAM approach in order to estimate the ranges of mutual inclinations that are compatible with the long-term stability in a KAM sense. Our method is successfully applied to the extrasolar systems HD 141399, HD 143761 and HD 40307.Comment: 19 pages, 3 figure

The emergent city. Interactive relational systems between public administration and citizen to foster sustainable processes of urban development

The widespread of Information and Communication Technologies and the consequently redefinition of roles in the usage and management of the city brought along new systems of relationships and interactions that produce an auto-organisation of territories or communities, showed also through temporary transformation of the environment. In effect, cities are continuously redefined by emergent properties that may, both be originated and then impact on social, political, cultural, and economical people practices. On the other hand, through the arrangement of its patterns the city shapes the social and connective relations occurring among people. So, the city can be regarded as a complex system, that in the last years has been expanded by the widespread of communication devices and sensors connected to the Internet. In this context, the design of new patterns of interactions that focuses on the new relationship opportunities, in part offered by the Information and Communication Technologies, but not limited to them, may significantly affect sustainable processes of urban development. This paper focuses on the civic aspect of the so-called smart cities, and, in details, on the relation between citizens and Public Administration. Some existing interaction patterns are illustrated in order to support the visualisation of the dynamic relationships between citizens and Public Administration, while new possible relations derived by the interaction with the urban space are supposed

Experimental Evaluation of Handover Strategies in 5G-MEC Scenario by using AdvantEDGE

The 5G-MEC architecture increases the heterogene-ity and dynamicity of the available resources, presenting unique and competing challenges to researchers, network designers, and application developers. Recent studies indicate AdvantEDGE as an interesting emulation platform to investigate these challenges. The paper presents a particular example of AdvantEDGE usage. A testbed composed of the emulated 5G-MEC architecture and the VideoLAN application allows to analyse the performance of alternative handover strategies, developed by using a multi-objective approach. The study shows how AdvantEDGE allows a deep analysis of the behaviour of the different strategies during the emulated user mobility, giving the possibility of measuring performance parameters at different layers, i.e. IP, application, and end-user

Synthesis and Crystal Structure of Bis(2-phenylpyridine-C,N')-bis(acetonitrile)iridium(III)hexafluorophosphate Showing Three Anion/Cation Couples in the Asymmetric Unit

The title compound bis(2-phenylpyridine-C,N')-bis(acetonitrile)iridium(III)hexafluorophosphate, a six-coordinate iridium(III) complex, crystallizes in the P-1 space group. Iridium is in a distorted octahedral (n = 6) coordination with the N,C' atoms of two phenylpyridine and the N atoms of two acetonitrile ligands. The peculiarity of this structure is that three independent moieties of the title compound and three PF6− anions, to counterbalance the charge, are observed in the asymmetric unit and this is a rather uncommon fact among the Cambridge Crystallographic Database (CSD) entries. The three couples are almost identical conformers with very similar torsional angles. The packing, symmetry, and space group were accurately analyzed and described also by means of Hirshfeld surface analysis, which is able to underline subtle differences among the three anion/cation couples in the asymmetric unit. The driving force of the packing is the clustering of the aromatic rings and the maximization of acetonitrile:PF6− interactions. The asymmetry of the cluster is the cause of the unusual number of moieties in the asymmetric unit

Joint multi-objective MEH selection and traffic path computation in 5G-MEC systems

Multi-access Edge Computing (MEC) is an emerging technology that allows to reduce the service latency and traffic congestion and to enable cloud offloading and context awareness. MEC consists in deploying computing devices, called MEC Hosts (MEHs), close to the user. Given the mobility of the user, several problems rise. The first problem is to select a MEH to run the service requested by the user. Another problem is to select the path to steer the traffic from the user to the selected MEH. The paper jointly addresses these two problems. First, the paper proposes a procedure to create a graph that is able to capture both network-layer and application-layer performance. Then, the proposed graph is used to apply the Multi-objective Dijkstra Algorithm (MDA), a technique used for multi-objective optimization problems, in order to find solutions to the addressed problems by simultaneously considering different performance metrics and constraints. To evaluate the performance of MDA, the paper implements a testbed based on AdvantEDGE and Kubernetes to migrate a VideoLAN application between two MEHs. A controller has been realized to integrate MDA with the 5G-MEC system in the testbed. The results show that MDA is able to perform the migration with a limited impact on the network performance and user experience. The lack of migration would instead lead to a severe reduction of the user experience.publishedVersio

Bioaccumulation of Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Dibenzofurans (PCDFs) in Hediste diversicolor (Polychaeta: Nereididae)

The effectiveness and reliability of the polychaete Hediste diversicolor (O.F. Müller, 1776) to bioaccumulate polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) was assessed in an in-situ passive biomonitoring study. Field collected specimens were sampled in five sites within the Venice Lagoon (Italy), selected along a PCDD/F contamination gradient. The homolog profiles in the tissues of the common ragworm were considerably different from those observed in the sediments, independent of sediment contamination. Moreover, H. diversicolor accumulated preferentially the less chlorinated 2,3,7,8-TCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF compared to the more chlorinated and hydrophobic hexa-, hepta- and octa-substituted congeners, as evidenced by the significant and linearly decreasing trend of the Biota-to-Sediment Accumulation Factor (BSAF) with the increasing lipophilicity of the congeners, expressed as the logarithmic form of the octanol/water partition coefficient (logKOW). The BSAFs for dioxins and furans were generally low compared to other organochlorine compounds such as polychlorinated biphenyls and organochlorine pesticides, suggesting that H. diversicolor may eliminate both dioxins and furans efficiently

Inhibition of Larval Development of Marine Copepods Acartia tonsa by Neonocotinoids

Neonicotinoids (NEOs) are neurotoxic pesticides widely used in agriculture due to their high effectiveness against pest insects. Despite their widespread use, very little is known about their toxicity towards marine organisms, including sensitive and ecologically relevant taxa such as copepods. Thus, we investigated the toxicity of five widely used NEOs, including acetamiprid (ACE), clothianidin (CLO), imidacloprid (IMI), thiacloprid (THI), and thiamethoxam (TMX), to assess their ability to inhibit the larval development of the copepod Acartia tonsa. The more toxic NEOs were ACE (EC50 = 0.73 μg L−1), TMX (EC50 = 1.71 μg L−1) and CLO (EC50 = 1.90 μg L−1), while the less toxic compound was IMI (EC50 = 8.84 μg L−1). Early life-stage mortality was unaffected by NEOs at all of the tested concentrations. The calculated toxicity data indicated that significant effects due to ACE (EC20 = 0.12 μg L−1), THI (EC20 = 0.88 μg L−1) and TMX (EC20 = 0.18 μg L−1) are observed at concentrations lower than established chronic aquatic life benchmarks reported by USEPA for freshwater invertebrates. Nevertheless, since environmental concentrations of NEOs are generally lower than the threshold concentrations we calculated for A. tonsa, the effects may be currently of concern only in estuaries receiving wastewater discharges or experiencing intense runoff from agricultur