Seismicity Pattern Changes before the M = 4.8 Aeolian Archipelago (Italy) Earthquake of August 16, 2010

We investigated the seismicity patterns associated with an earthquake recorded in the Aeolian Archipelago on 16, August, 2010, by means of the region-time-length (RTL) algorithm. This earthquake triggered landslides at Lipari; a rock fall on the flanks of the Vulcano, Lipari, and Salina islands, and some damages to the village of Lipari. The RTL algorithm is widely used for investigating precursory seismicity changes before large and moderate earthquakes. We examined both the spatial and temporal characteristics of seismicity changes in the Aeolian Archipelago region before the earthquake. The results obtained reveal 6-7 months of seismic quiescence which started about 15 months before the earthquake. The spatial distribution shows an extensive area characterized by seismic quiescence that suggests a relationship between quiescence and the Aeolian Archipelago regional tectonics

ka band phase locked loop oscillator dielectric resonator oscillator for satellite ehf band receiver

This paper describes the design and fabrication of a Ka Band PLL DRO having a fundamental oscillation frequency of 19.250 GHz, used as local oscillator in the low-noise block of a down converter (LNB) for an EHF band receiver. Apposite circuital models have been created to describe the behaviour of the dielectric resonator and of the active component used in the oscillator core. The DRO characterization and measurements have shown very good agreement with simulation results. A good phase noise performance is obtained by using a very highQdielectric resonator

High precision tilt observation at Mt. Etna Volcano, Italy

In 2007-2008, we installed on Mt. Etna two deep tilt stations using high resolution, self-leveling instruments. These installations are the result of accurate instrument tests, site selection, drilling and sensor positioning that has allowed detecting variations related to the principal diurnal and semidiurnal tides for first time on Mt. Etna using tilt data. We analyzed the tidal effects recorded on tilt signals and we removed tidal effects from signals, thereby allowing to detect changes of about 20 nanoradians with a considerable improvement respect to the previous installation. Tilt changes have accompanied the Mt. Etna main eruptive phases and are generally related to the rapid rise of magma and formation of dikes and eruptive fissures. However, tilt changes characterize lava fountains, earthquakes and inflation-deflation phases. The 2008-2009 eruption represents an example of the potential of these tiltmeters providing new perspectives for highly precise monitoring of ground deformation on volcanoes

INSTALLAZIONE DI UN CLINOMETRO AD ALTA PRECISIONE IN AREA TETTONICA (SETTORE NORD-ORIENTALE DELL’ALTIPIANO IBLEO)

In questo rapporto sono riportati i dettagli dell’installazione di un clinometro profondo effettuata nel 2010 in prossimità di Pedagaggi (SR) nel settore nord-orientale dell’altipiano ibleo. L'installazione è stata possibile utilizzando uno strumento digitale autolivellante modello AGI (Applied Geomechanics Incorporated) Lily, con sensibilità pari a 0.005 microradianti. Sono illustrati i dettagli dell’installazione ed i primi dati che evidenziano la loro ottima qualità, la presenza delle componenti mareali e la minima variazione di inclinazione ottenibile ripulendo il segnale dalle stesse

Tilt measurements at Vulcano Island

A network of tiltmeters has been operational on Vulcano Island for numerous years. At present, the network comprises five functioning borehole stations, four of which are installed at 8-10 m and allow recording very stable, high precision signals with very low noise. We report observations over the last 12 years that illustrate impulsive variations linked to seismicity and long-term (several years) trends in the signals. We suggest a relationship between tilt changes correlated to the strongest regional seismic events and site acceleration; long-term tilt variations analyzed in combination with other ground deformation data seem to represent the evidence of a contraction of the La Fossa cone. We also analyzed how the tilt device has the capability to detect possible magma migrations; we considered previous studies that have imaged spatially well-defined levels of magma accumulation beneath La Fossa, and Vulcanello; we concluded that the Vulcano tilt network should be capable of detecting the upward migration of small magma volumes. Finally, we show that no evidence of changes are visible on tilt signals during anomalous degassing episodes (linked to a building up input of magmatic fluids) at the La Fossa thereby evidencing that no magma migration occurred during such events

Scalable synchronization of spin-Hall oscillators in out-of-plane field

A strategy for a scalable synchronization of an array of spin-Hall oscillators (SHOs) is illustrated. In detail, we present micromagnetic simulations of two and five SHOs realized by means of couples of triangular golden contacts on the top of a Pt/CoFeB/Ta trilayer. Results highlight that the synchronization occurs for the whole current region that gives rise to the excitation of self-oscillations. This is linked to the role of the magnetodipolar coupling, which is the phenomenon driving the synchronization when the distance between oscillators is not too large. Synchronization turns out to be also robust against geometrical differences of the contacts, simulated by considering variable distances between the tips ranging from 100nm to 200nm. Besides, it entails an enlargement of the radiation pattern that can be useful for the generation of spin-waves in magnonics applications. Simulations performed to study the effect of the interfacial Dzyaloshinskii-Moriya interaction show nonreciprocity in spatial propagation of the synchronized spin-wave. The simplicity of the geometry and the robustness of the achieved synchronization make this design of array of SHOs scalable for a larger number of synchronized oscillators

REALIZZAZIONE DI UN SITO TEST PER CLINOMETRI DI TIPO BORE-HOLE

Questo lavoro riporta la descrizione dei lavori di realizzazione di un sito test ubicato in Catania presso il Centro Unificato Acquisizione Dati (CUAD) costituito da 4 fori contigui che ha lo scopo di testare il funzionamento e l’affidabilità di clinometri bore-hole prima della loro installazione finale. Il sito si presta per la sperimentazione su diversi strumenti attraverso il confronto di segnali registrati contemporaneamente a più sensori. Sono riportati e discussi i primi risultati di una installazione multipla di strumenti di diverso tipo (Mod 510, Mod. 722 e Mod. Lily tutti prodotti dall’Applied Geomechanincs) evidenziando le problematiche e le affinità sulla base dei dati registrati

Installazione nell'area etnea di un clinometro digitale in foro profondo 30 metri.

Questo lavoro riporta i risultati della prima installazione clinometrica ad alta profondità effettuata su aree vulcaniche italiane. L'installazione, nata da una collaborazione fra INGV-CT e Provincia Regionale di Catania, è stata possibile grazie all'utilizzo di strumentazione digitale autolivellante di nuova generazione; lo strumento utilizzato è un clinometro modello AGI (Applied Geomechanics Incorporation) con sensibilità pari a 0.005 microradianti (AGI Mod. LILY). Sono illustrati i dettagli dell’installazione e i primi due mesi di dati che evidenziano l’ottima qualità dei dati che risultano essere priva di effetti legati alla temperatura e le cui uniche oscillazioni, dell’ordine di 0.1-0.2 microrad, sono legate alle mareali

Modulation of spinal excitability following neuromuscular electrical stimulation superimposed to voluntary contraction

Purpose. Neuromuscular electrical stimulation (NMES) superimposed on voluntary muscle contraction has been recently shown as an innovative training modality within sport and rehabilitation, but its effects on the neuromuscular system are still unclear. The aim of this study was to investigate acute responses in spinal excitability, as measured by the Hoffmann (H) reflex, and in maximal voluntary contraction (MVIC) following NMES superimposed to voluntary isometric contractions (NMES+ISO) compared to passive NMES only and to voluntary isometric contractions only (ISO). Method. Fifteen young adults were required to maintain an ankle plantar-flexor torque of 20% MVC for 20 repetitions during each experimental condition (NMES+ISO, NMES and ISO). Surface electromyography was used to record peak-to-peak Hreflex and motor waves following percutaneous stimulation of the posterior tibial nerve in the dominant limb. An isokinetic dynamometer was used to assess maximal voluntary contraction output of the ankle plantar flexor muscles. Results. H-reflex amplitude was increased by 4.5% after the NMES+ISO condition (p < 0.05), while passive NMES and ISO conditions showed a decrease by 7.8% (p < 0.05) and no change in reflex responses, respectively. There was no change in amplitude of maximal motor wave and in MVIC torque during each experimental condition. Conclusion. The reported facilitation of spinal excitability following NMES+ISO could be due to a combination of greater motor neuronal and corticospinal excitability, thus suggesting that NMES superimposed onto isometric voluntary contractions may provide a more effective neuromuscular stimulus and, hence, training modality compared to NMES alone

Adherence issues related to sublingual immunotherapy as perceived by allergists

Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd