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Background Coronary computed tomography angiography (CCTA) is an established technique for non-invasive evaluation of the coronary arteries. Whereas artifacts limit the assessment of the stented vessels, studies supported its performance in vessels treated with first generation bioresorbable scaffold (BRS). Anatomical findings can be integrated with non-invasive fractional flow reserve (FFR-CT) to discriminate the presence or not of flow-limiting disease. After the failure of the first BRS generation, alternative platforms have been developed, including the second-generation resorbable magnesium scaffold (RMS). Ongoing studies investigate the long-term safety and effectiveness of RMS, but few evidence describes their performance with CCTA. Aims The present investigation aims to report the luminal measurement, FFR-CT assessment, and clinical outcomes, in the first patients treated with RMS in the Scaffold Implantation in Emilia-Romagna Plus Multi Absorbable Gears Intra Coronary (SHERPA-MAGIC) study. Methods As prespecified sub-study, patients underwent CCTA 18 months after RMS implantation. Three-dimensional models were reconstructed for simulation of coronary flow and pressure. FFR-CT analysis was performed using the DeepVessel FFR software (Keya Medical, Seattle, WA, USA). Results From December 2017 to July 2018, 34 patients underwent RMS implantation. After exclusion of 7 patients due to additional drug eluting stent (DES) implantation, poor CCTA quality and CCTA refusal, the population included 26 patients. Overall, 29 vessels were treated with 35 RMS. Median stent length was 25 [20-25] mm, with a median diameter of 3 [3-3.5] mm. Three-year follow-up was available for all patients. One patient received revascularization of the target vessel after 18-month CCTA. Another patient was admitted for atypical chest pain 12 months after index procedure. Quantitative analysis was feasible in all vessels (n=29). Complete RMS reabsorption was observed in 27 cases. Median minimal lumen diameter (MLD) and area (MLA) of the scaffolded segments were 2.5 [2.1-2.8] mm and 6.4 [4.4-8.4] mm2, respectively. Non-invasive FFR analysis was feasible in 23 vessels (80%). The causes for missing computation were artifacts and the incomplete documentation of the entire coronary artery. Median FFR-CT in the target vessels was 0.88 [0.81-0.91]. Ttwo target vessels showed a flow-limiting FFR-CT value. In the first case, the patient underwent coronary artery angiography. Invasive FFR confirmed a flow-limiting stenosis (FFR value 0.74), and a new PCI was performed. In the second case, the patient was asymptomatic in optimal medical therapy, and mid-distal LAD was involved (FFR-CT value 0.79). Conclusions In a highly selected population of patients undergoing RMS implantation with a standardized technique, CCTA is feasible and allows to discriminate long-term anatomical and functional performance of scaffolded segments.

The combined use of Unmanned Aerial Vehicles (UAVs) and Structure from Motion (SfM) photogrammetry allows the collection and processing of high-resolution data on demand, which is key for the constant and detailed monitoring of the fluvial environment. In addition, through the ever-increasing development of new techniques of mapping and data processing (i.e., UAVs swarm, BVLOS flight missions, high-performance photogrammetry workflow), it is now possible to detect large areas at high-resolution, providing support for spatiotemporal insights into hydro-geomorphological processes and hazard assessment, in order to ensure an effective management and to prevent catastrophic phenomena (i.e., floods). The main goal of this paper is to use UAV-based high-resolution topographic data to constrain the probabilistic hazard assessment of extended reaches of Basento river (Basilicata, Italy). To demonstrate the influence of geomorphology and riverbed sediment on hazard assessment, a sensitivity analysis was carried out on the resolution of the UAV-derived DEMs; on the riverbed roughness coefficient resulting from photo-sieving analysis and on the morphological change detection over short-time ranges (2019-2021). We found that lower resolution DEMs lead to an increase of flooding probability (in several river cross-sections an increase even higher than 99 % resulted), and that a greater roughness coefficient involves an increase in the probability of flooding (with a maximum increase of about 9 %). Moreover, the multitemporal high-resolution outputs resulting from SfM allowed the identification of morphological changes, in short-times, caused by an anthropic modification of the river bank, which significantly affected the flooding hazard.

Aims The revascularization strategy to pursue in older myocardial infarction (MI) patients with multivessel disease (MVD) is currently unknown. For this reason, while waiting for the results of dedicated trials, we sought to compare a complete vs. a culprit-only strategy in older MI patients by merging data from four registries. Methods and results The inclusion criteria for the target population of the present study were: (i) age ≥75 years; (ii) MI (STE or NSTE); (iii) MVD; and (iv) successful treatment of culprit lesion. Propensity scores (PS) were derived using logistic regression (backwards stepwise selection, P Conclusions Culprit-only is the default strategy in older MI patients with MVD. In our analysis, complete revascularization was associated with lower all-cause and CV mortality and with a lower MI rate.

Morphometric analyses are based on multiparametric data sets that describe quantitatively the shapes of objects. The stochastic nature of fracture formation processes that break up magma during explosive eruptions yields mixtures of particles that have highly varied shapes. In volcanology, morphometric analysis is applied to these mixtures of particles with diverse shapes for two purposes: (1) to fingerprint tephra from individual eruptions and use the fingerprints to distinguish among tephra layers and determine their extents and (2) to reconstruct eruption processes, by linking particles formed by known fragmentation processes in experiments with particles from natural pyroclastic deposits. Here, we review the most commonly adopted statistical techniques for morphometric analysis of pyroclasts. We provide sets of objects with different shapes, along with their morphometric data, in order to demonstrate and illustrate the methods. They can be used not only for addressing the processes of fragmentation during explosive eruptions, but also for the characterization of other types of solid particles with complex morphologies.

Pyroclastic density currents are ground hugging gas-particle flows associated to explosive volcanic eruptions and moving down a volcano's slope, causing devastation and deaths. Because of the hostile nature they cannot be analyzed directly and most of their fluid dynamic behavior is reconstructed by the deposits left in the geological record, which frequently show peculiar structures such as ripples and dune bedforms. Here, a set of equations is simplified to link flow behavior to particle motion and deposition. This allows to construct a phase diagram by which impact parameters of dilute pyroclastic density currents, representing important factors of hazard, can be calculated by inverting bedforms wavelength and grain size, without the need of more complex models that require extensive work in the laboratory.

Pyroclastic density currents are ground hugging gas-particle flows moving at high speed down the volcano slope. They are among the most hazardous events of explosive volcanism, causing devastation and deaths1,2. Because of the hostile nature they cannot be analyzed directly and most of their fluid dynamic behavior is reconstructed by the deposits left in the geological record, which frequently show peculiar structures such as bedforms of the types of ripples and dunes3,4. In this paper, we simplify a set of equations that link flow behavior to particle motion and deposition. This allows, for the first time, the build up of a phase diagram by which the hazard of dilute pyroclastic density currents can be explored easily and quickly by inverting bedforms wavelength and grain size.

Background: Transcatheter ablation is the standasrd treatment for atrioventricular nodal re-entrant tachycardia (AVNRT). However, different techniques are available. Data about the use of irrigated flexible-tip catheters and three-dimensional electroanatomical mapping (3D EAM) for AVNRT ablation are scant. The aim of this study was to evaluate in long-term follow-up efficacy and safety of a novel approach for AVNRT treatment. Methods: This is a cohort single arm study with long-term follow-up. Patients with AVNRT were treated with catheter ablation by means of irrigated flexible-tip catheters combined with 3D EAM. Results: One-hundred-and-fifty patients were enrolled and followed-up for a median of 38 months (minimum 12, maximum 74). Acute procedural success rate was 96.7% (145/150 patients). During follow-up, 11 patients had arrhythmia recurrences (7.3%). No patient developed atrioventricular conduction block with need for pacemaker implantation (0%). Fourteen patients died during follow-up (9.3%). Conclusions: Acute procedural success and long-term follow-up show that AVNRT could be safely and effectively treated with irrigated flexible-tip catheters and 3D EAM.

Pyroclastic density currents are ground hugging gas-particle flows that originate from the collapse of an eruption column or lava dome. They move away from the volcano at high speed, causing devastation. The impact is generally associated with flow dynamic pressure and temperature. Little emphasis has yet been given to flow duration, although it is emerging that the survival of people engulfed in a current strongly depends on the exposure time. The AD 79 event of Somma-Vesuvius is used here to demonstrate the impact of pyroclastic density currents on humans during an historical eruption. At Herculaneum, at the foot of the volcano, the temperature and strength of the flow were so high that survival was impossible. At Pompeii, in the distal area, we use a new model indicating that the current had low strength and low temperature, which is confirmed by the absence of signs of trauma on corpses. Under such conditions, survival should have been possible if the current lasted a few minutes or less. Instead, our calculations demonstrate a flow duration of 17 min, long enough to make lethal the breathing of ash suspended in the current. We conclude that in distal areas where the mechanical and thermal effects of a pyroclastic density currents are diminished, flow duration is the key for survival.

The sedimentological, lithological and textural characteristics of the Brown Tuffs (BT) pyroclastic deposits, combined with their grain-size, componentry and geochemical glass compositions, are here investigated to obtain information on the transport and depositional mechanisms of the corresponding pyroclastic density currents (PDCs). The BT are widespread reddish-brown to grey, ash-rich pyroclastic deposits generated by pulsating hydromagmatic explosive activity from the La Fossa Caldera on Vulcano island during the c. 80–6 ka time-stratigraphic interval, and then distributed on most of the Aeolian Islands and Capo Milazzo peninsula (Sicily) and in the Tyrrhenian and Adriatic Sea regions. Near the source area on Vulcano, the BT are characterised by alternating massive and planar to cross stratified lithofacies that result from the stepwise, repeating aggradation of discrete PDC pulses. This alternance is regulated by either fluid escape or granular flow depositional regimes at high clast concentration or grain by grain traction deposition in the waning diluted stages of the PDCs. Most of the BT on Vulcano show intermittently stratified and massive ash deposits resulting from a pervasive post-depositional disruption of the primary structures. This is induced by upward fluid expulsion associated with dissipation of pore pressure between layers at different grain size (fine to coarse ash) and porosity, as outlined by distinctive upwards bends and pillar-type escape structures through the fluid-filled cracks and rupture points. Massive BT deposits with a faint colour and grain-size banding are widely recognised on Lipari, the nearby island of Vulcano. Based on the presence, at the base of BT depositional units, of cm-thick amalgamation bands containing pumice lapilli, scoria and lithic clasts ripped-up and embedded from the loose underlying pyroclastic units, they are interpreted as deposited by ash-rich PDCs laterally spreading from La Fossa Caldera and moving to Lipari. During their motion to Lipari these currents (likely) crossed a narrow and shallow sea-water inlet which did not stop their advancement but influenced the grain size distribution of those spreading on the Lipari mainland. In this paper, the mechanism of clast erosion and incorporation is outlined across the whole island of Lipari by means of field study, grain-size, and geochemical glass analyses on the different components of the mixed basal bands of the BT. This suggests that the BT PDCs maintained enough flow power as to erode the substratum, hence likely impacting the territory, over a distance up to at least 16–17 km from the volcanic source. Evidence that the BT PDCs exerted a high shear-stress over the loose substratum is also provided by undulated, recumbent flame and rip-up structures at the base of some depositional units in southern and central Lipari. In order to form such bed granular instabilities between the BT and the underlying deposits we calculate that the currents had at least a shear velocity of ca. 2 m s−1 and a shear stress in the range of 1–4.5 kPa. These results add new insights on the large-scale hazard at the Aeolian Islands and shed new lights on the widespread transport and depositional dynamics of ash flows spreading over the sea and reaching nearby islands, and their interactions with the substratum and the pre-depositional topography.

In this paper we illustrate the stratigraphy, geochronology, and geochemistry (major, minor, trace elements and Sr-isotopes) of a Holocene tephra layer found within coastal sedimentary deposits north of Caleta Olivia (Santa Cruz Province, Argentina). The stratigraphic succession comprises beach deposits with basal erosive surface resting on the local substrate (“Formacion Patagonia”) followed by a poorly developed paleosoil. The paleosoil is covered by a lenticular fine-grained (Mdφ: 5.2, 0.027 mm), well sorted (σφ: 1.2) volcanic ash layer and aeolian sands. The geochemical composition of shard fragments points to an origin from the Hudson volcano, located in the southern Andes, ca. 400 km to the west. The geochemistry, Sr-isotopes and the radiometric constraints (younger than the age of the underlying marine layer dated at ca. 4,100 a cal BP) further allow correlating this tephra with the so-called H2 eruption (ca. 3,900 a cal BP). This finding is of interest owing to the poor preservation potential of tephra within the Late Holocene sedimentary deposits of the Atlantic coast of Patagonia and represents the first finding of H2 eruption in this area, improving our knowledge of the dispersion of the fine-grained distal deposit of the Hudson volcanic explosive activity, thus allowing a better estimate of the eruptive dynamics and the risks associated with the Hudson volcano., Este artículo aborda la estratigrafía, geocronología y geoquímica (elementos mayoritarios, minoritarios, trazas e isótopos de Sr) de un nivel de tefra holocena que forma parte de una secuencia de sedimentos costeros ubicados al norte de Caleta Olivia (provincia de Santa Cruz, Argentina). La secuencia comprende depósitos sedimentarios que se disponen sobre una superficie basal erosiva que suprayace al sustrato local (“Formación Patagonia”), y continúa esta secuencia con un paleosuelo de escaso desarrollo. El paleosuelo está cubierto por una capa lenticular de cenizas volcánicas de grano fino (Mdφ: 5,2, 0,027 mm), bien seleccionada (σφ: 1,2) y arenas eólicas. La composición geoquímica de los shards indica que esta tefra se originó en el volcán Hudson, ubicado en los Andes del sur, a aproximadamente 400 km hacia el oeste. La geoquímica, los isótopos de Sr y las restricciones radiométricas (más joven que la edad de la capa marina que la subyace, fechada en aproximadamente 4.100 a cal AP) permiten correlacionar esta tefra con la denominada erupción H2 de dicho volcán (ocurrida aproximadamente 3.900 a cal AP). Este hallazgo es de interés debido al escaso potencial de preservación de los depósitos de tefra dentro de las secuencias sedimentarias costeras del Holoceno Tardío, en la costa atlántica de Patagonia y representa el primer hallazgo del evento eruptivo H2 en esta área, lo cual contribuye a mejorar el conocimiento sobre la dispersión de la tefra generada por la actividad volcánica explosiva del volcán Hudson, lo que permite una mejor estimación de la dinámica eruptiva y los riesgos asociados con este volcán., Centro de Estudios Integrales de la Dinámica Exógena

Among the cutting-edge techniques that are being using in the meteoritics discipline to explore potential new properties, the micro-CT is useful in its potential of showing phase distribution in a 3D reconstruction and analyses of a small meteorite volume and in showing microstructures, crystal habits or grains, occurrences of vesicles or voids, melt veins and fractures. In this view, we studied a sample of Al Haggounia, a meteorite significantly porous with pore sizes from several cm to hundreds of microns. This meteorite after a complex history of classification results to be an EL-impact melt. The fragments show very different looking, from the point of view of microstructure of impact shock: melt veins, fractures and pores and, consequently, this meteorite is particularly suitable for investigations by micro-CT coupling with SEM-EDS analyses to fit the chemical data to the textural ones. All the data obtained help us in the genetic interpretation allowing to verify the hypothesis about the origin of this meteorite developed until now.

In this paper, we present results of the reconstruction of the total grain size distribution (TGSD) of the material erupted during explosive volcanic eruptions at Campi Flegrei (Italy) considering all components (juvenile, lithic and crystal clasts). To date, the few TGSDs made available have been mostly reconstructed by assuming that the tephra deposits consisted of only one component. This simplification can introduce substantial bias in the interpretation of magma fragmentation mechanisms and significantly affect ash dispersion forecasts, since each tephra component has specific aerodynamic characteristics. By means of field investigations and laboratory analyses on samples collected from deposits of the Agnano-Monte Spina and Astroni eruptions, we reconstructed the TGSDs of juvenile, lithic and crystal components via the Voronoi tessellation method. Our results show how the systematic reconstruction of a TGSD, from the component-specific to the bulk TGSD, can provide important information on magma fragmentation mechanisms and wall-rock erosion processes. Results confirm that the bulk TGSD is the combination of the merging of different component subpopulations, according to their own TGSD, density and relative mass proportions. In addition, the integration of component analysis, TGSD and settling velocity data allowed characterization of the aerodynamic behaviour of each component at variable distances from the vent, which can be related to their own parent grain size distribution. The integration of new data from distal tephra deposits for the considered eruptions has thus allowed a reassessment of the erupted volumes of eruptions considered in this research, which are now 3.17 and 0.63 km3, for Agnano-Monte Spina and Astroni, respectively.

The majority of Earth's volcanic eruptions occur beneath the sea, but the limited number of direct observations and samples limits our understanding of these unseen events. Subaerial eruptions lend some insight, but direct extrapolation from the subaerial to the deep sea is precluded by the great differences in pressure, thermal conditions, density and rheology, and the interplay among them. Here we present laboratory fragmentation experiments that mimic deep-sea explosive eruptions and compare our laboratory observations with those from the kilometre-deep submarine eruption of Havre Volcano, Kermadec Arc, New Zealand, in 2012. We find that the Havre eruption involved explosive fragmentation of magma by a pressure-insensitive interaction between cool water and hot magma, termed an induced fuel-coolant interaction. The laboratory experiments show that this water-magma interaction is initiated by the formation of cracks in cooling magma into which the water coolant can infiltrate, driving explosive fragmentation. Explosive submarine eruptions have previously been considered unlikely because stabilization of a vapour film at the magma-water contact was thought to be a key requirement but is suppressed at depths exceeding 100 m. However, here we demonstrate that these induced fuel-coolant interactions between magma and water can occur in a range of wet environments regardless of pressure, from the subaerial to the deep sea, and may operate on different planets, as well as apply to materials other than magma and water.

Objectives: The study aims to investigate occupational exposure to carbon fibers impregnated with epoxy resins (carbon fiber reinforced [CFR]) in workers at an airplane fuselage section construction plant, by environmental and biological monitoring. Materials and methods: Determination of airborne CFR was done by environmental sampling with active samplers, 11 of which were stationary and 19 personal samplings. The subsequent analyses were performed in the scanning electron microscope fitted with an X-ray microanalysis system (SEM-EDXA). Biological monitoring was carried out by determining CFR in exhaled breath condensate (EBC) collected from 19 male workers who wore personal environmental samplers (exposed workers) and from 10 male workers at the same factory who had no occupational exposure to CFR (internal controls). CFR analysis was done by SEM, applying the method used for determining asbestos fibers in aqueous samples. Results: The airborne CFR concentrations were found to be significantly higher (p = 0.03) at personal samplings (median value 7.01 ff/L, range 1.24–11.16 ff/L) than stationary samplings (median value 1.93 ff/L, range 0.55–10.09 ff/L). The aerodynamic diameters calculated starting from the length and geometric diameter of the sampled CFRs were always higher than 20 µm. CFR was not found in any of the EBC samples collected from the exposed workers and controls. Conclusions: Despite the evidence of occupational exposure to low concentrations of CFR, the absence of such fibers in the EBC in the exposed workers confirms their non-respirability, as expected based on their aerodynamic diameter.

Dense gas‐particle jets similar to collapsing eruption columns were generated by large‐scale experiments. The column collapse resulted in a ground‐hugging current forming stratified layers with bedding similar to natural pyroclastic density current deposits. At the impact of the collapsing column on the ground, a thick, massive bed was formed due to a high sedimentation rate that dumped turbulence due to high clast concentration. Down‐current, flow expansion favoured turbulence and dilute gas‐particle current that formed thin rippled layers deposited under traction. Experiments fed with fine ash (median size 0·066 mm) formed deposits without tractional structures, because fine particles, as other sedimentary fine material, is cohesive and exposes a limited surface to the shear stress. Experimental outcomes show that massive beds are formed where the sedimentation rate per unit width Srw exceeds the bedload transportation rate Qb by two orders of magnitude. A lower ratio generates traction at the base of the flow and formation of shear structures that increase in wavelength and height with a decreasing flux. This study presents a diagram that provides a useful addition for facies analysis of pyroclastic density currents, provided that deposits representing sustained sedimentation can be identified in the field. In the diagram a decrease in the Srw/Qb ratio corresponds to an increase in bedform size. Application of the diagram for hazard assessment purposes allows the reconstruction of the mass eruption rate of the Agnano–Monte Spina eruption at Campi Flegrei, which is the main variable defining the intensity of past eruptions, and of the Bingham rheology of the massive underflow of the Mercato pyroclastic density current at Vesuvius.

International audience; Among the active volcanoes worldwide, Somma-Vesuvius is one with the highest volcanic risk as the surrounding areas are highly populated. Somma-Vesuvius is quiescent since 1944, but geological and historical records reveal a frequent violent explosive activity in the last 4000 years, representing a severe risk for the ∼700,000 inhabitants currently living in the area having a high probability for being impacted by pyroclastic density currents ("red zone") and more than one million people who can be potentially affected by tephra fallout. This study aims to analyze the distribution and grain-size of tephra fallout deposits from several Somma-Vesuvius eruptions of different styles, ranging from Violent Strombolian to sub-Plinian and Plinian, for characterizing the associated magmatic fragmentation through the assessment of their total grain-size distribution (TGSD). Chronologically, we focus on the Avellino (4365 BP) and Pompeii (A.D. 79) Plinian eruptions, the Pollena (A.D. 472) sub-Plinian eruption, and the 1906 and 1944 Violent Strombolian eruptions. The related TGSDs were estimated by means of the Voronoi tessellation method, which requires a suitable number of local grain-size distributions and estimation of the area of minimum tephra loading (zero-line contour). However, field-derived TGSDs can be biased towards the coarse and fine grain-size populations due to the typical paucity of available field outcrops of fallout deposits. To encompass this issue, we performed a sensitivity study on the assumption behind TGSD reconstructions and described TGSDs through analytical grain-size distributions that best fit the field TGSDs. Our main objective is a more robust estimation of the TGSDs associated with the different eruptive styles, which is crucial, together with the other eruption source parameters, for robustly predicting tephra loading and airborne ash dispersal of future eruptions at Somma-Vesuvius.

Background: A 61-year-old male with Steinert Dystrophy and prior history of cardiac implantable device complained of highly symptomatic right atrial tachycardia. Unresponsive to pharmacological therapy. Methods: The patient underwent catheter ablation procedure aided by high-density mapping. Results: Ablation procedure was succesful. Conclusions: This unique case report highlights the role of high-density mapping in the identification of critical isthmus and management of macro-reentrant tachycardia in complex situations such as the presence of multiple leads in the chamber.

Large-scale experiments generating ground-hugging multiphase flows were carried out with the aim of modelling the rate of sedimentation, of pyroclastic density currents. The current was initiated by the impact on the ground of a dense gas-particle fountain issuing from a vertical conduit. On impact, a thick massive deposit was formed. The grain size of the massive deposit was almost identical to that of the mixture feeding the fountain, suggesting that similar layers formed at the impact of a natural volcanic fountain should be representative of the parent grain-size distribution of the eruption. The flow evolved laterally into a turbulent suspension current that sedimented a thin, tractive layer. A good correlation was found between the ratio of transported/sedimented load and the normalized Rouse number of the turbulent current. A model of the sedimentation rate was developed, which shows a relationship between grain size and flow runout. A current fed with coarser particles has a higher sedimentation rate, a larger grain-size selectivity and runs shorter than a current fed with finer particles. Application of the model to pyroclastic deposits of Vesuvius and Campi Flegrei of Southern Italy resulted in sedimentation rates falling inside the range of experiments and allowed definition of the duration of pyroclastic density currents which add important information on the hazard of such dangerous flows. The model could possibly be extended, in the future, to other geological density currents as, for example, turbidity currents. © 2018 International Association of Sedimentologists., DD is grateful for his Juan de la Cierva contract (JdC 2015) – MINECO.

New experiments of falling volcanic particles were performed in order to define terminal velocity models applicable in a wide range of Reynolds number Re. Experiments were carried out with fluids of various viscosities and with particles that cover a wide range of size, density and shape. Particle shape, which strongly influences fluid drag, was measured in 3D by High-resolution X-ray microtomography, by which sphericity Φ3D and fractal dimension D3D were obtained. They are easier to measure and less operator dependent than the 2D shape parameters used in previous papers. Drag laws that make use of the new 3D parameters were obtained by fitting particle data to the experiments, and single-equation terminal velocity models were derived. They work well both at high and low Re (3 × 10− 2 < Re < 104), while earlier formulations made use of different equations at different ranges of Re. The new drag laws are well suited for the modelling of particle transportation both in the eruptive column, where coarse and fine particles are present, and also in the distal part of the umbrella region, where fine ash is involved in the large-scale domains of atmospheric circulation. A table of the typical values of Φ3D and D3D of particles from known plinian, subplinian and ash plume eruptions is presented. Graphs of terminal velocity as a function of grain size are finally proposed as tools to help volcanologists and atmosphere scientists to model particle transportation of explosive eruptions.

Bernd Zimanowski and Ralf Büttner shared with the authors the experiment design and development. They are gratefully thanked. The paper greatly benefited from the revision of Gert Lube and Kristen Fauria. Published with permission of the Executive Director of British Geological Survey (UKRI). Data can be found at the Zenodo repository with the following link https://zenodo.org/search?page=1&size=20&q=dellino, with DOI 10.5281/zenodo.3408690., The entrainment rate of pyroclastic density currents is investigated by large‐scale experiments. The ground flows are initiated by the impact on the terrain of a dense gas‐particle fountain issuing from a cylindrical conduit, similarly to natural volcanic events. On impact, the excess density with respect to the surrounding atmosphere was up to 11.6 kg/m3, making the currents non‐Boussinesq. A power law model of the entrainment rate is developed, which is similar to that proposed for snow avalanches by Ancey (2004, https://doi.org/10.1029/2003JF000052) and is verified for the Richardson's number range between 0.25 and 5.95. Rapid changes of the entrainment are caused by (i) strong accelerations at the fountain impact on the ground; (ii) break in slope; and (iii) topographic obstacles. Such changes, together with the sedimentation rate, influence flow mobility. The use of the power law is suggested for modeling the motion of unsteady hazardous geophysical mass flows such as pyroclastic density currents and snow avalanches.

The development of new bi- and tri-dimensional (2D, 3D) analytical techniques of volcanic materials represents a new frontier in the world of modern volcanology. These advances not only offer important and reliable information on, e.g., magma vesiculation, degassing, and crystallization processes but can also shade light on the transport and sedimentation processes in volcanic flows (e.g. pyroclastic density currents, volcanic clouds). Hence, these novel approaches have the potential to contribute both to the understanding eruption dynamics towards volcanic hazard quantification.

Magnetite nanoparticles (NPs) were synthetized by partial oxidation of hot Fe(II) sulfate aqueous solutions upon addition of variable amounts of alkali/nitrate ions in a N2 atmosphere. The resulting NPs were extensively characterized by Scanning Electron Microscopy (SEM), X-Ray Powder Diffraction (XRPD), Dynamic Light Scattering (DLS) and Brunauer-Emmett-Teller (BET) analysis. Depending on the final pH after synthesis, partially oxidized magnetite NPs were obtained with average crystallite size ranging from 29 to 116 nm. The potential of NPs as arsenic adsorbents was investigated through batch adsorption experiments. The analysis of the adsorption isotherms performed on the basis of both Freundlich and Langmuir models, revealed that arsenic adsorption capacity was more efficient for magnetite NPs synthetized at final pH ≤ 6.56, characterized by polydisperse submicrometric aggregates with coarse macro- and mesopore distributions.

Super-deep diamonds and their mineral inclusions preserve very precious information about Earth’s deep mantle. In this study, we examined multiphase inclusions entrapped within a diamond from the Rio Vinte e um de Abril, Sao Luiz area (Juina, Brazil), using a combination of non-destructive methods. Micro-Computed X-ray Tomography (μ-CXRT) was used to investigate the size, shape, distribution and X-Ray absorption of inclusions and mapping by micro X-ray Fluorescence (μ-XRF), μ-Raman Spectroscopy and micro-Fourier Transform Infrared Spectroscopy (μ-FTIR) were used to determine the chemical and mineralogical composition of the inclusions. Four large inclusions enclosed in the N-rich diamond core consist of dominant ferropericlase–magnesiowustite and locally exsolved magnesioferrite. FTIR maps, obtained integrating the band at 1430 cm−1, show also the presence of carbonates. A fifth large inclusion (ca 100 μm) was remarkable because it showed a very unusual flask shape, resembling a fluid/melt inclusion. Based on μCXRT tomography and μ-Raman mapping, the flask-shaped inclusion is polyphase and consists of magnetite and hematite partly replacing a magnesiowustite core and small-volume of gas/vacuum. μ-Raman spectra on the same inclusion revealed local features that are ascribed to post-spinel polymorphs, such as maohokite or xieite, which are stable at P ≥ 18 GPa, and to huntite, a carbonate with formula CaMg3(CO3)4. This represents the first finding of maohokite and huntite in diamond. We interpret the composition of the inclusions as evidence of formation of ferropericlase–magnesiowustite and diamond in a carbonate-rich environment at depths corresponding at least to the Transition Zone, followed by oxidation of ferropericlase–magnesiowustite by reaction with relatively large-volume entrapped melt during diamond ascent.

Ancient Herculaneum papyrus scrolls, hopelessly charred in the 79 A.D. Vesuvius eruption, contain valuable writings of the Greek philosophers of the day, including works of the Epicurean Philodemus. X-ray phase contrast tomography has recently begun unlocking their secrets. However, only small portions of the text hidden inside the scroll have been recover. One of the challenging tasks in Herculaneum papyri investigation is their virtual unfolding because of their highly complicated structure and three-dimensional arrangement. Although this procedure is feasible, problems in segmentation and flattening hinder the unrolling of a large portion of papyrus. We propose a computational platform for the virtual unfolding procedure, and we show the results of its application on two Herculaneum papyrus fragments. This work paves the way to a comprehensive survey and to further interpretation of larger portions of text hidden inside the carbonized Herculaneum papyri.

The Lesina Marina village (Apulia, southern Italy) lies on an exotic rocky body basically composed of Triassic gypsum surrounded and covered by thin Quaternary sandy deposits. During the last two decades instability phenomena connected to gypsum dissolution and cover suffusion sinkholes occurred mainly along the Acquarotta canal and in the urbanized area. In this study, electrical resistivity tomographies, field and petrographic observations have been carried out just ca. 300 m to the South of the residential area. The East–West striking geoelectrical profile has a length of 1900 m, intercepts two boreholes and crosscuts the Acquarotta canal. Close to the boreholes, higher resolution geoelectrical profiles, both perpendicular and parallel to the former, were performed. The two boreholes highlight the presence, from the top to the bottom, of Quaternary sandy deposits, coarse grained gypsum and layered finer grained gypsum. In correspondence, electrical resistivities are very low for the wet sandy deposits (up to 5 Ω·m), increase for coarse grained gypsum (20–120 Ω·m) and reach the maximum values for the layered finer grained gypsum (greater than 300 Ω·m). The relationship between the electrical resistivity and the lithological composition of the studied rocks is strongly controlled by their fracturing and water saturation degree. Thus considering, the main geological features here recovered are the impermeable bedrock and the above rocky body involved by mineral transformations and karstification phenomena. Additionally, the anhydrite/gypsum transformation and the gypsum dissolution are related to the groundwater circulation and localized within massive coarse grained gypsum rocks. Therefore, the hazard related to karst processes involves both an area and a depth greater than those considered up to now.

PURPOSE OF INVESTIGATION: Aim of the study was to evaluate the possible involvement of zinc in the complex pathogenic process behind the onset and perpetuation of endometriotic lesions. To study the level of zinc serum between a group of patients affected by endometriosis and a group of healthy patients. MATERIALS AND METHODS: The study included 86 women: 42 patients whose histodiagnosis had revealed pelvic endometriosis and 44 healthy patients. The authors measured the serum zinc concentration for all patients. RESULTS: The group of patients with endometriosis presented serum zinc concentration of 1010 +/- 59.24 microg/l. The observation group presented a serum zinc concentration of 1294 +/- 62.22 microg/l. CONCLUSION: The results showed that serum zinc levels in women with endometriosis are decreased and this seems to actually confirm that this microelement can possibly affect the multifactorial pathogenesis of the disease. As a matter of fact, zinc interferes with many biological processes, among which inflammation and immunity, which seem to be the base of the development of the lesions. Therefore, the authors believe that this hypothesis requires more attention and further investigation to determine its reasonableness. If the results are confirmed, this study opens up future prospects as for the treatment of endometriosis, taking into account also the role of zinc in the onset of male sterility and the development of testicles. Zinc could in fact be used as marker to detect women at high risk of endometriosis and for the elaboration of a new treatment for sterility, from which these women often suffer.