Integration of Satellites in 5G through LEO Constellations

The standardization of 5G systems is entering in its critical phase, with 3GPP that will publish the PHY standard by June 2017. In order to meet the demanding 5G requirements both in terms of large throughput and global connectivity, Satellite Communications provide a valuable resource to extend and complement terrestrial networks. In this context, we consider a heterogeneous architecture in which a LEO mega-constellation satellite system provides backhaul connectivity to terrestrial 5G Relay Nodes, which create an on-ground 5G network. Since large delays and Doppler shifts related to satellite channels pose severe challenges to terrestrial-based systems, in this paper we assess their impact on the future 5G PHY and MAC layer procedures. In addition, solutions are proposed for Random Access, waveform numerology, and HARQ procedures.Comment: Submitted to IEEE Global Communications Conference (GLOBECOM) 201

Average Rate of Downlink Heterogeneous Cellular Networks over Generalized Fading Channels - A Stochastic Geometry Approach

In this paper, we introduce an analytical framework to compute the average rate of downlink heterogeneous cellular networks. The framework leverages recent application of stochastic geometry to other-cell interference modeling and analysis. The heterogeneous cellular network is modeled as the superposition of many tiers of Base Stations (BSs) having different transmit power, density, path-loss exponent, fading parameters and distribution, and unequal biasing for flexible tier association. A long-term averaged maximum biased-received-power tier association is considered. The positions of the BSs in each tier are modeled as points of an independent Poisson Point Process (PPP). Under these assumptions, we introduce a new analytical methodology to evaluate the average rate, which avoids the computation of the Coverage Probability (Pcov) and needs only the Moment Generating Function (MGF) of the aggregate interference at the probe mobile terminal. The distinguishable characteristic of our analytical methodology consists in providing a tractable and numerically efficient framework that is applicable to general fading distributions, including composite fading channels with small- and mid-scale fluctuations. In addition, our method can efficiently handle correlated Log-Normal shadowing with little increase of the computational complexity. The proposed MGF-based approach needs the computation of either a single or a two-fold numerical integral, thus reducing the complexity of Pcov-based frameworks, which require, for general fading distributions, the computation of a four-fold integral.Comment: Accepted for publication in IEEE Transactions on Communications, to appea

Metabotropic glutamate 2/3 receptors and epigenetic modifications in psychotic disorders: a review

Schizophrenia and Bipolar Disorder are chronic psychiatric disorders, both considered as "major psychosis"; they are thought to share some pathogenetic factors involving a dysfunctional gene x environment interaction. Alterations in the glutamatergic transmission have been suggested to be involved in the pathogenesis of psychosis. Our group developed an epigenetic model of schizophrenia originated by Prenatal Restraint Stress (PRS) paradigm in mice. PRS mice developed some behavioral alterations observed in schizophrenic patients and classic animal models of schizophrenia, i.e. deficits in social interaction, locomotor activity and prepulse inhibition. They also showed specific changes in promoter DNA methylation activity of genes related to schizophrenia such as reelin, BDNF and GAD67, and altered expression and function of mGlu2/3 receptors in the frontal cortex. Interestingly, behavioral and molecular alterations were reversed by treatment with mGlu2/3 agonists. Based on these findings, we speculate that pharmacological modulation of these receptors could have a great impact on early phase treatment of psychosis together with the possibility to modulate specific epigenetic key protein involved in the development of psychosis. In this review, we will discuss in more details the specific features of the PRS mice as a suitable epigenetic model for major psychosis. We will then focus on key proteins of chromatin remodeling machinery as potential target for new pharmacological treatment through the activation of metabotropic glutamate receptors

Epigenetic Alterations in Prenatal Stress Mice as an Endophenotype Model for Schizophrenia: Role of Metabotropic Glutamate 2/3 Receptors

Mice subjected to prenatal restraint stress (PRS mice) showed biochemical and behavioral abnormalities consistent with a schizophrenia-like phenotype (Matrisciano et al., 2016). PRS mice are characterized by increased DNA-methyltransferase 1 (DNMT1) and ten-eleven methylcytosine dioxygenase 1 (TET1) expression levels and exhibit an enrichment of 5-methylcytosine (5MC) and 5-hydroxymethylcytosine (5HMC) at neocortical GABAergic and glutamatergic gene promoters. Activation of group II metabotropic glutamate receptors (mGlu2 and−3 receptors) showed a potential epigenetically-induced antipsychotic activity by reversing the molecular and behavioral changes observed in PRS mice. This effect was most likely caused by the increase in the expression of growth arrest and DNA damage 45-β (Gadd45-β) protein, a molecular player of DNA demethylation, induced by the activation of mGlu2/3 receptors. This effect was mimicked by clozapine and valproate but not by haloperidol. Treatment with the selective mGlu2/3 receptors agonist LY379268 also increased the amount of Gadd45-β bound to specific promoter regions of reelin, BDNF, and GAD67. A meta-analysis of several clinical trials showed that treatment with an orthosteric mGlu2/3 receptor agonist improved both positive and negative symptoms of schizophrenia, but only in patients who were early-in-disease and had not been treated with atypical antipsychotic drugs (Kinon et al., 2015). Our findings show that PRS mice are valuable model for the study of epigenetic mechanisms involved in the pathogenesis of schizophrenia and support the hypothesis that pharmacological modulation of mGlu2/3 receptors could impact the early phase of schizophrenia and related neurodevelopmental disorders by regulating epigenetic processes that lie at the core of the disorders

Analysis of coexistence and mutual interference between mobile and digital television systems

La creciente demanda de servicios de comunicaciones inalámbricas multimedia es un factor clave en los mercados más desarrollados. Así, las palabras de moda en las comunicaciones personales “acceso para cualquier persona, en cualquier sitio, en cualquier momento y para el servicio deseado”, implican una demanda notoria y creciente del Espectro Radioeléctrico. En este sentido, la última Conferencia Mundial de Radiocomunicaciones 2007 (CMR-07) atribuyó la parte alta de la banda UHF a las redes móviles como servicio co-primario a partir del 2015 en la Región 1, aprovechando el Dividendo Digital debido a la mayor eficiencia espectral de la TV digital con respecto a la analógica. Esto tiene el potencial de causar una interferencia perjudicial entre los sistemas de televisión y los sistemas móviles y necesita ser analizado con atención. En este artículo presentamos un estudio del problema de la interferencia co-canal en dicho escenario, proponiendo una metodología para tener en cuenta la interferencia entre una red móvil LTE y un sistema televisivo DVB-T, poniendo de relieve el comportamiento diferente de los dos radioenlaces.The ever increasing demand for multimedia wireless communication systems is a key feature of more advanced markets. The buzzwords of personal communications, meant to provide “access to anyone, anywhere, at anytime to the wanted service”, implies that radio spectrum demands are dramatically increasing in most developed markets. The last World Radiocommunication Conference (WRC-07) allocated on a co-primary basis the upper part of the UHF band to mobile services as from 2015 in Region 1, taking advantage of the Digital Dividend due to the higher spectrum efficiency of digital TV with respect to the analogue system. This will cause potentially harmful mutual interference between TV and mobile radio services, that needs to be carefully analysed. In this paper we present a study of the co-channel interference problem, proposing a methodology to take into account the mutual interference between a LTE mobile network and a DVB-T system and highlighting the different behaviour of the two radio links

ACLEESCF. SP. FOVEATUS(COLEOPTERA CURCULIONIDAE), AN EXOTIC PESTOF FICUS CARICAIN ITALY: A SUSTAINABLE APPROACH TO DEFENCE BASEDON ALUMINOSILICATE MINERALS AS HOST PLANT MASKING SOLIDS

The exceptionally frequent entries of alien pest are a major source of concern for the farmers who haveto protect their crops from unknown insects, often without natural enemies in the new areas. A new pestbelonging to the Molytinae family (Coleoptera: Curculionidae), tribe Hylobiini, reported as Acleessp. cf.foveatusVoss, was recently introduced in Italy. The species is responsible for severe damages in many Italianfig nurseries and orchards, particularly in the Italian Central Northern regions, i.e. Tuscany, Ligury andLatium. Currently, no active ingredients are registered against this insect on fig crops. An innovative and eco-friendly approach for controlling this exotic weevil infestation was investigated, by using montmorillonite-based clays, either in their native state or containing copper(II) species, and clinoptilolite zeolites, in order tocheck the perception of the adults’ weevil towards the different solid materials and, subsequently, to evaluatethe capability of these innovative products to act as masking agent with respect to the host plant and/or asrepellent upon contact. The formulations containing copper(II)-exchanged clay and clinoptilolite zeoliteshowed preliminary promising results in terms of efficacy and environmental sustainability