180 research outputs found
High precision locations of long-period events at La Fossa Crater (Vulcano Island, Italy)
Since the last eruption in 1888-90, the volcanic activity on Vulcano Island (Aeolian Archipelago, Italy) has been limited to fumarolic degassing. Fumaroles are mainly concentred at the active cone of La Fossa in the northern sector of the island and are periodically characterized by increases in temperature as well as in the amount of both CO2 and He. Seismic background activity at Vulcano is dominated by micro-seismicity originating at shallow depth
Illumination Correction on Biomedical Images
RF-Inhomogeneity Correction (aka bias) artifact is an important research field in Magnetic Resonance Imaging (MRI). Bias corrupts MR images altering their illumination even though they are acquired with the most recent scanners. Homomorphic Unsharp Masking (HUM) is a filtering technique aimed at correcting illumination inhomogeneity, but it produces a halo around the edges as a side effect. In this paper a novel correction scheme based on HUM is proposed to correct the artifact mentioned above without introducing the halo. A wide experimentation has been performed on MR images. The method has been tuned and evaluated using the simulated Brainweb image database. In this framework, the approach has been compared successfully against the Guillemaud filter and the SPM2 method. Moreover, the method has been successfully applied on several real MR images of the brain (0.18 T, 1.5 T and 7 T). The description of the overall technique is reported along with the experimental results that show its effectiveness in different anatomical regions and its ability to compensate both underexposed and overexposed areas. Our approach is also effective on non-radiological images, like retinal ones
Dynamics of Vulcano Island investigated by long-term (40 years) geophysical data
Vulcano island is a composite volcanic edifice located in the south-central sector of the Aeolian Archipelago (Tyrrhenian Sea, Italy) and it is an important tourist destination. Historic activity has been characterized by frequent transitions from phereatomagmatic to minor magmatic activity. The last eruption in 1888-90 was characterized by energetic explosive pulses and defines the “vulcanian” type of activity. Since then, volcanic activity has taken the form of fumarolic emanations of variable intensity and temperature, mainly concentrated at “La Fossa” crater, with maximum temperatures ranging between 200° and 300° C; temperature increases and changes in the gas chemistry, were often observed. The most recent episode began in the 80’s when fumarole temperature progressively increased to 690°C in May 1993. Vulcano is active and this favoured monitoring and research studies, in particular focussed on the most recent structures.
In the frame of DPC-INGV “V3” project, we investigate the Vulcano dynamics through ca. 40 years of ground deformation and seismicity data collected by the discrete and continuous INGV monitoring networks. We considered levelling, GPS, EDM, seismic and tilt data. EDM and levelling measurements began in the middle 1970s and since the late 1990s the EDM benchmarks have been measurered using GPS.
We observed three scales of ground deformation: the first one seems to be linked to the regional tectonics, with a general transpressive kinematics; the second one affects the northern half of the island and could be related to the caldera dynamics; the third one affects only the cone of La Fossa. Regional tectonic stress seems to play an important role in the transition of the volcanic system from a phase of stability to a phase of unrest, inducing the heating and the expansion of shallow hydrothermal fluids. Ground deformation at Vulcano may be linked to the geothermal system rather than magmatic sources
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Recent advances of HCI in decision-making tasks for optimized clinical workflows and precision medicine.
The ever-increasing amount of biomedical data is enabling new large-scale studies, even though ad hoc computational solutions are required. The most recent Machine Learning (ML) and Artificial Intelligence (AI) techniques have been achieving outstanding performance and an important impact in clinical research, aiming at precision medicine, as well as improving healthcare workflows. However, the inherent heterogeneity and uncertainty in the healthcare information sources pose new compelling challenges for clinicians in their decision-making tasks. Only the proper combination of AI and human intelligence capabilities, by explicitly taking into account effective and safe interaction paradigms, can permit the delivery of care that outperforms what either can do separately. Therefore, Human-Computer Interaction (HCI) plays a crucial role in the design of software oriented to decision-making in medicine. In this work, we systematically review and discuss several research fields strictly linked to HCI and clinical decision-making, by subdividing the articles into six themes, namely: Interfaces, Visualization, Electronic Health Records, Devices, Usability, and Clinical Decision Support Systems. However, these articles typically present overlaps among the themes, revealing that HCI inter-connects multiple topics. With the goal of focusing on HCI and design aspects, the articles under consideration were grouped into four clusters. The advances in AI can effectively support the physicians' cognitive processes, which certainly play a central role in decision-making tasks because the human mental behavior cannot be completely emulated and captured; the human mind might solve a complex problem even without a statistically significant amount of data by relying upon domain knowledge. For this reason, technology must focus on interactive solutions for supporting the physicians effectively in their daily activities, by exploiting their unique knowledge and evidence-based reasoning, as well as improving the various aspects highlighted in this review
High precision locations of long-period events at La Fossa Crater (Vulcano Island, Italy)
Since the last eruption in 1888-90, the volcanic activity on Vulcano Island (Aeolian Archipelago, Italy) has been limited to fumarolic degassing. Fumaroles are mainly concentred at the active cone of La Fossa in the northern sector of the island and are periodically characterized by increases in temperature as well as in the amount of both CO2 and He. Seismic background activity at Vulcano is dominated by micro-seismicity originating at shallow depth (<1-1.5 km) under La Fossa cone. This seismicity is related to geothermal system processes and comprises long period (LP) events. LPs are generally considered as the resonance of a fluid-filled volume in response to a trigger. We analyzed LP events recorded during an anomalous degassing period (August-October 2006) applying a high precision technique to define the shape of the trigger source. Absolute and high precision locations suggest that LP events recorded at Vulcano during 2006 were produced by a shallow focal zone ca. 200 m long, 40 m wide and N30-40E oriented. Their occurrence is linked to magmatic fluid inputs that by modifying the hydrothermal system cause excitation of a fluid-filled cavity
Ultrafast flow of interacting organic polaritons
The strong-coupling of an excitonic transition with an electromagnetic mode
results in composite quasi-particles called exciton-polaritons, which have been
shown to combine the best properties of their bare components in semiconductor
microcavities. However, the physics and applications of polariton flows in
organic materials and at room temperature are still unexplored because of the
poor photon confinement in such structures. Here we demonstrate that polaritons
formed by the hybridization of organic excitons with a Bloch Surface Wave are
able to propagate for hundreds of microns showing remarkable third-order
nonlinear interactions upon high injection density. These findings pave the way
for the studies of organic nonlinear light-matter fluxes and for a
technological promising route of dissipation-less on-chip polariton devices
working at room temperature.Comment: Improved version with polariton-polariton interactions. 13 pages, 4
figures, supporting 6 pages, 6 figure
SVILUPPO DI UN SOFTWARE PER LA DETEZIONE E CLASSIFICAZIONE IN NEAR REAL-TIME DEGLI EVENTI SISMO-VULCANICI DI VULCANO
Heat flux-based strategies for the thermal monitoring of sub-fumarolic areas: Examples from Vulcano and La Soufrière de Guadeloupe
Although it is relatively easy to set-up, the monitoring of soil temperature in sub-fumarolic areas is quite rarely
used to monitor the evolution of hydrothermal systems. Indeed, measurements are highly sensitive to environmental
conditions, in particular daily and seasonal variations of atmospheric temperatures and rainfalls, which
can be only partially filtered by the established statistical analysis. In this paper, we develop two innovative processingmethods,
both based on the computation of the heat flux in the soil. The upward heat flux method (UHF),
designed for dry environments, consists in computing both the conductive and convective components of the
heat flux between two thermocouples placed vertically. In the cases of wet environments, the excess of total
heat method (ETH) allows the integration of rain gauges data in order to correct the heat balance fromthe superficial
cooling effect of the precipitations. The performances of both processing techniques are faced to established
methods (temperature gradient and coefficient of determination) on soil temperature time series from two test
volcanoes. At La Fossa di Vulcano (Italy), the UHF method undoubtedly detects three thermal crises between
2009 and 2012, enabling to quantify not only the intensity but also the precise timing of the heat flux increase
with respect to corresponding geochemical and seismic crises. At La Soufrière de Guadeloupe (French Lesser Antilles),
despite large rainfalls dramatically influencing the thermal behavior of the soil, a constant geothermal heat
flux is retrieved by the ETH method, confirming the absence of fumarolic crisis during the observation period
(February–August 2010). Being quantitative, robust, and usable in almost any context of sub-fumarolic zones,
our two heat flux-based methods increase the potential of soil temperature for the monitoring, but also the general
interpretation of fumarolic crises together with geochemical and seismological observations. A spreadsheet
allowing direct computation of UHF and ETH is provided as supplemental material.Published122-1342V. Struttura e sistema di alimentazione dei vulcaniJCR Journa
BODIPY-based conjugated polymers for broadband light sensing and harvesting applications
The synthesis of novel low band-gap polymers has significantly improved light sensing and harvesting in polymer-fullerene devices. Here the synthesis of two low band-gap polymers based on the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene core (BODIPY), and either bis(3,4-ethylenedioxythiophene) (bis-EDOT) or its all-sulfur analogue bis(3,4-ethylenedithiathiophene) (bis-EDTT) are described. The polymers demonstrate ambipolar charge transport and are shown to be suitable for broadband light sensing and solar energy harvesting in solution-processable polymer-fullerene devices
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