Decentralized Triangular Guidance Algorithms for Formations of UAVs

This paper deals with the design of a guidance control system for a swarm of unmanned aerial systems flying at a given altitude, addressing flight formation requirements that can be formulated constraining the swarm to be on the nodes of a triangular mesh. Three decentralized guidance algorithms are presented. A classical fixed leader–follower scheme is compared with two alternative schemes: the former is based on the self-identification of one or more time-varying leaders; the latter is an algorithm without leaders. Several operational scenarios have been simulated involving swarms with obstacles and an increasing number of aircraft in order to prove the effectiveness of the proposed guidance schem

Modeling and control of a modular iron bird

This paper describes the control architecture and the control laws of a new concept of Modular Iron Bird aimed at reproducing flight loads to test mobile aerodynamic control surface actuators for small and medium size aircraft and Unmanned Aerial Vehicles. The iron bird control system must guarantee the actuation of counteracting forces. On one side, a hydraulic actuator simulates the hinge moments acting on the mobile surface due to aerodynamic and inertial effects during flight; on the other side, the actuator to be tested applies an active hinge moment to control the angular position of the same surface. Reference aerodynamic and inertial loads are generated by a flight simulation module to reproduce more realistic conditions arising during operations. The design of the control action is based on a dynamic model of the hydraulic plant used to generate loads. This system is controlled using a Proportional Integral Derivative control algorithm tuned with an optimization algorithm taking into account the closed loop dynamics of the actuator under testing, uncertainties and disturbances in the controlled plant. Numerical simulations are presented to show the effectiveness of the proposed architecture and control laws

Carbohydrate-mediated interactions between chloroviruses and the immune system

Understanding the molecular mechanisms which drive and modulate host-pathogen interactions are essential when designing effective therapeutic and diagnostic approaches aimed at controlling infectious diseases. Certain large and giant viruses have recently been discovered as components of the human virome, yet little is known about their interactions with the host immune system. We have dissected the role of viral N-linked glycans during the interaction between the glycoproteins from six chloroviruses (belonging to three chlorovirus classes: NC64A, SAG, and Osy viruses) and the representative carbohydrate-binding receptors of the innate immune system. Using solid-phase assays we have identified the binding of viral glycoproteins to different C-type lectins in a carbohydrate-dependent manner. These experiments verified the importance of D-rhamnose in modulating their binding to C-type lectins DC-SIGN and Langerin. In vitro assays further determined the ability of the chlorovirus glycoproteins to trigger secretion of cytokines Interleukins 6 and 10 (IL-6 and IL-10) in human monocyte-derived dendritic cells and mouse macrophages. Additionally, IgG from healthy human controls recognized certain chlorovirus glycoproteins, indicating the significance of human environmental viral exposures. Collectively, these results demonstrate the ability of the innate and adaptive immune systems to recognize chlorovirus glycoproteins, a process dependent on their specific N-glycan structures

Unveiling the GT114 family: Structural characterization of A075L, a glycosyltransferase from Paramecium bursaria chlorella virus-1 (PBCV-1)

Protein A075L is a β-xylosyltransferase that participates in producing the core of the N-glycans found in VP54, the major viral capsid protein of Paramecium bursaria chlorella virus-1 (PBCV-1). In this study, we present an X-ray crystallographic analysis of the apo form of A075L, along with its complexes with the sugar donor and with a trisaccharide acceptor. The protein structure shows a typical GT-B folding, with two Rossmann-like fold domains, in which the acceptor substrate binds to the N-terminal region, and the nucleotide-sugar donor binds to the C-terminal region. We propose that the catalytic mechanism follows a direct displacement SN2-like reaction, where Asp73 serves as a catalytic base that deprotonates the incoming nucleophile of the acceptor, facilitating direct displacement of the UDP with the inversion of the anomeric configuration of the acceptor without metal ion dependence, while the interactions with side chains of Arg158 and Arg208 stabilize the developing negative charge. Using isothermal titration calorimetry, nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, and molecular dynamics simulations, the catalytic activity and specificity of this enzyme have been unraveled

Safe and effective liver-directed AAV-mediated homology-independent targeted integration in mouse models of inherited diseases

: Liver-directed adeno-associated viral (AAV) vector-mediated homology-independent targeted integration (AAV-HITI) by CRISPR-Cas9 at the highly transcribed albumin locus is under investigation to provide sustained transgene expression following neonatal treatment. We show that targeting the 3' end of the albumin locus results in productive integration in about 15% of mouse hepatocytes achieving therapeutic levels of systemic proteins in two mouse models of inherited diseases. We demonstrate that full-length HITI donor DNA is preferentially integrated upon nuclease cleavage and that, despite partial AAV genome integrations in the target locus, no gross chromosomal rearrangements or insertions/deletions at off-target sites are found. In line with this, no evidence of hepatocellular carcinoma is observed within the 1-year follow-up. Finally, AAV-HITI is effective at vector doses considered safe if directly translated to humans providing therapeutic efficacy in the adult liver in addition to newborn. Overall, our data support the development of this liver-directed AAV-based knockin strategy

State-of-the-art:AI through the (artificial) Artist’s Eye

This paper builds on the premise that art has a significant role to play in engaging with and exploring new technologies and in contributing to interdisciplinary conversations. Artists have often been pioneers in reflecting upon social and technological transformations by creating work that makes explicit the dangers, but also the exciting possibilities ushered in by innovation. After having, albeit briefly, traced the history of art engagement with technology (computer/net-art, generative art), the paper will focus on AI-art, now defined as GAI-art, to understand whether artificial intelligence is “set to become art’s next medium?” The question was prompted by the sale at Christie’s in October 2018 for $432,500 of a portrait entitled Edmund de Belamy, a work created by an algorithm called Generative Adversarial Network (GAN). The source code used by the Paris based art collective Obvious (borrowed from AI researcher/artist Robbie Barrat) to create the “artwork” triggered a debate as to the authenticity, authorship and ethics of using GAN to produce AI-art. The paper will contribute to such debate by exploring also the implications of systems more sophisticated than GAN - which seem to be able to act as “autonomous artificial artists” and produce new styles of art - and by showcasing the works of some of the most representative machine vision researchers/artists - Anna Ridler and Mario Klingeman, among others. AI artworks raise major philosophical questions, the meaning to be human in a hyper-connected world and the true nature of human creativity. In fact conceptualising AI through the artificial artist’s eye might even challenge our understanding of what it means to be human

Gravity, Geodesy and Fundamental Physics with BepiColombo’s MORE Investigation

open40siThe Mercury Orbiter Radio Science Experiment (MORE) of the ESA mission BepiColombo will provide an accurate estimation of Mercury’s gravity field and rotational state, improved tests of general relativity, and a novel deep space navigation system. The key experimental setup entails a highly stable, multi-frequency radio link in X and Ka band, enabling two-way range rate measurements of 3 micron/s at nearly all solar elongation angles. In addition, a high chip rate, pseudo-noise ranging system has already been tested at 1-2 cm accuracy. The tracking data will be used together with the measurements of the Italian Spring Accelerometer to provide a pseudo drag free environment for the data analysis. We summarize the existing literature published over the past years and report on the overall configuration of the experiment, its operations in cruise and at Mercury, and the expected scientific results.openIess L.; Asmar S.W.; Cappuccio P.; Cascioli G.; De Marchi F.; di Stefano I.; Genova A.; Ashby N.; Barriot J.P.; Bender P.; Benedetto C.; Border J.S.; Budnik F.; Ciarcia S.; Damour T.; Dehant V.; Di Achille G.; Di Ruscio A.; Fienga A.; Formaro R.; Klioner S.; Konopliv A.; Lemaitre A.; Longo F.; Mercolino M.; Mitri G.; Notaro V.; Olivieri A.; Paik M.; Palli A.; Schettino G.; Serra D.; Simone L.; Tommei G.; Tortora P.; Van Hoolst T.; Vokrouhlicky D.; Watkins M.; Wu X.; Zannoni M.Iess L.; Asmar S.W.; Cappuccio P.; Cascioli G.; De Marchi F.; di Stefano I.; Genova A.; Ashby N.; Barriot J.P.; Bender P.; Benedetto C.; Border J.S.; Budnik F.; Ciarcia S.; Damour T.; Dehant V.; Di Achille G.; Di Ruscio A.; Fienga A.; Formaro R.; Klioner S.; Konopliv A.; Lemaitre A.; Longo F.; Mercolino M.; Mitri G.; Notaro V.; Olivieri A.; Paik M.; Palli A.; Schettino G.; Serra D.; Simone L.; Tommei G.; Tortora P.; Van Hoolst T.; Vokrouhlicky D.; Watkins M.; Wu X.; Zannoni M