ENVIRONMENTAL FACTORS IMPACT AND INCIDENCE OF PARASITISMOF PSYLLAEPHAGUS BLITEUSRIEK (HYMENOPTERA ENCYRTIDAE)ON POPULATIONS OF GLYCASPIS BRIMBLECOMBEIMOORE(HEMIPTERA APHALARIDAE) IN MEDITERRANEAN CLIMATIC AREAS

The red gum lerp psyllid, Glycaspis brimblecombeiMoore (Hemiptera, Aphalaridae), is an Australian native sap-sucking insect pest of eucalypts that has been first reported for the West Palaearctic Region in 2008 and, in 2010, it hasbeen found also in Italy. Subsequently its primary parasitoid, Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae),was also detected within the main European and North African infested areas, where no release of the parasitoid was everperformed. This study, carried out in 30 Eucalyptus camaldulensis plantations located along the coast, on the hills andthe mountains in Mediterranean climatic areas of Sicily (Italy), aimed to determine the influence of environmentalparameters on the incidence of both, the psyllid infestation level and the parasitization activity. P. bliteusreached high-est average levels in summer samplings and resulted widespread in Sicily at all detected altitudes without statisticallysignificant differences. P. bliteus parasitization is the main factor lowering G. brimblecombei infestation; this result,together with the accidental and contemporaneous arrival of the host and its parasitoid, could explain the absence of highdamage level on eucalypts in Sicily. The most significant metric factors positively influencing G. brimblecombei infes-tation are the percentage of daily hours above 80% of relative humidity and the average maximum temperature, obvi-ously related to other, but less significant climatic factors. The altitude affects both infestation and parasitization, but sin-gle sites could explain significantly more, so that the local conditions where the samplings were carried out have to beconsidered as the main responsibles for the variability in the obtained results. In any sampled Sicilian site, from sea levelto 540 m a.s.l., both the psyllid and its parasitoids show a good adaptation to climatic conditions, confirming that areasfitting for E. camaldulensisgrowth fit also for P. bliteus activity, and proving that Mediterranean climate, differently fromsome inland areas of California, does not obstacle its parasitic activity

A New Method for the Experimental Assessment of Finger Haemodynamic Effects Induced by a Hydraulic Breaker in Operative Conditions

Abstract: A New Method for the Experimental Assessment of Finger Haemodynamic Effects Induced by a Hydraulic Breaker in Operative Conditions: Matteo VALENTINO, et al

An X-ray burst from a magnetar enlightening the mechanism of fast radio bursts

Fast radio bursts (FRBs) are millisecond radio pulses originating from powerful enigmatic sources at extragalactic distances. Neutron stars with large magnetic fields (magnetars) have been considered as the sources powering the FRBs, but the connection requires further substantiation. Here we report the detection by the AGILE satellite on 28 April 2020 of an X-ray burst in temporal coincidence with a bright FRB-like radio burst from the Galactic magnetar SGR 1935+2154. The burst observed in the hard X-ray band (18-60 keV) lasted about 0.5 s, it is spectrally cut off above 80 keV and implies an isotropically emitted energy of about 1040 erg. This event demonstrates that a magnetar can produce X-ray bursts in coincidence with FRB-like radio bursts. It also suggests that FRBs associated with magnetars can emit X-ray bursts. We discuss SGR 1935+2154 in the context of FRBs with low-intermediate radio energies in the range 1038-1040 erg. Magnetars with magnetic fields B ≈ 1015 G may power these FRBs, and new data on the search for X-ray emission from FRBs are presented. We constrain the bursting X-ray energy of the nearby FRB 180916 to be less than 1046 erg, smaller than that observed in giant flares from Galactic magnetars

Transistor a film sottile con strato attivo di pentacene: stabilità elettrica in differenti condizioni ambientali e studio di materiali per strati di passivazione

I transistor a film sottile organici (OTFT, Organic Thin Film Transistors) hanno assunto negli ultimi anni un ruolo sempre più importante nella microelettronica su larga area (LAM, Large Area Microelectronics). Il crescente interesse rivolto a questi dispositivi è dovut o alla possibilità di coniugare un costo relativamente basso con proprietà innovative come flessibilità meccanica, basse temperature di processo (che permettono l’utilizzo di substrati plastici e polimerici), e prestazioni del tutto paragonabili e in diversi casi migliori di quelle dei transistor realizzati in silicio amorfo. Gli “organic semiconductors” offrono oggi le loro prestazioni per numerosissime applicazioni soprattutto come diodi organici emet titori di luce (AMOLED), nella tecnologia delle smart -card completamente plastiche, e delle tag di identificazione elettronica, nei backplanes a matrice attiva delle “e-papers” e in generale in tutte le applicazioni riguardanti quella che viene chiamata “Flexible Organic and Large Area Electronics” (FOLAE) In questa tesi vengono ampiamente analizzati transistor a film sottile con canale in pentacene. Tale semiconduttore organico oggi permette di ottenere dispositivo con alte prestazioni. D’altro canto, la diffusione di diverse spec ie molecolari nello strato attivo può causare instabilità nelle caratteristiche elettriche, richiedendo l’utilizzo di strati incapsulanti per le zone attive dei dispositivi. Sono stati così utilizzati come strati di passivazione film di PTFE, depositati utilizzando diverse miscele CHF3/Argon in una camera RIE. Il PTFE consente l’effettuazione di processi fotolitografici sul pentacene favorendo anche l’utilizzo di “annealing” termici che migliorano ulteriormente le prestazioni elettriche dei dispositivi incapsulati. Simulazioni numeriche 1D evidenziano che le variazioni delle caratteristiche causate dalla deposizione di PTFE sono dovute alla presenza di un transistor parassita di retro -canale causata dalla formazione di carica e stati all’interfaccia tra strato attivo e incapsulante. Le misure effettuate in aria mostrano che il PTFE non blocca efficacemente la diffusione di acqua nello strato attivo, tuttavia permette l’uso di ricotture termiche che incrementano la stabilità dei dispositivi in aria. Infine l’analisi dell’invecchiamento in ossigeno sui dispositivi incapsulati prova che il PTFE blocca efficacemente la diffusione di ossigeno

Using Cryo-EM to Investigate Bacterial Secretion Systems

International audienceBacterial secretion systems are responsible for releasing macromolecules to the extracellular milieu or directly into other cells. These membrane complexes are associated with pathogenicity and bacterial fitness. Understanding of these large assemblies has exponentially increased in the last few years thanks to electron microscopy. In fact, a revolution in this field has led to breakthroughs in characterizing the structures of secretion systems and other macromolecular machineries so as to obtain high-resolution images of complexes that could not be crystallized. In this review, we give a brief overview of structural advancements in the understanding of secretion systems, fo-cusing in particular on cryo-electron microscopy, whether tomography or single-particle analysis. We describe how such techniques have contributed to knowledge of the mechanism of macromolecule secretion in bacteria and the impact they will have in the future

Unified drain-current model of complementary p- and n-type OTFTs

A unified drain current model of complementary (p- and n-type) organic thin film transistors (OTFTs) is presented. The model is physically based and takes into account the detailed properties of the organic semiconductor through the density of states (DOS). The drain current depends on the geometrical and physical parameters of the transistor, on the applied gate, drain and source voltages, and on the surface potential at the source and drain contacts. An analytical expression of the surface potential is derived. The proposed model is validated with the numerical calculations and the measurements of both p- and n-type OTFTs fabricated in a printed complementary technology. The provided analyses show that the model is continuous, accurate, and includes the main physical effects taking place in complementary organic transistors. Thanks to its analytical and symmetric formulation, it is suitable for the design of organic integrated circuits. Moreover, the unified physical picture provided by the model enables the extraction of the OTFTs physical parameters, thus it is a very powerful tool for the technology characterization