Non-volcanic CO2 and CH4 degassing in an actively extending orogen, southern Apennines, Italy

The southern Apennines fold and thrust belt has been undergoing post-orogenic extension since ca. 700 kyr. Crustal extension controls active tectonics and seismogenesis in the mountain chain [1], with seismicity being characterized by low to moderate magnitude events punctuated by strong earthquakes [2]. Effective decoupling between deep and shallow structural levels is related to the strong rheological contrast produced by a fluid-saturated, clay-rich mélange zone interposed between buried autochthonous carbonates – continuous with those exposed in the Apulian foreland – and the allochthonous units. This mélange zone also acts as a seal preventing the migration of deep-seated aqueous fluids – as well as oil in the Basilicata region, which hosts the largest Europe’s onshore oil fields – towards the surface. On the other hand, the mountain belt is characterized by substantial gas flow, recorded as both distributed soil gas emissions and vigorous gas vents, associated with active faults at the surface. We measured a CO2 flux up to 34000 g/m-2 per day at a gas vent, as well as large amounts of He (up to 52 ppm), Rn (up to 228 kBq/m3) and CH4 (up to 5000 ppm). Overpressured CO2, which has been proposed as triggering normal fault earthquakes in the Apennines, has been interpreted as mostly of mantle origin. However, our new results from isotope analyses carried out on the carbon contained in both CO2 and CH4 indicate a dominant thermogenic origin for these gases, probably associated with the emplacement of magmatic sills within the lower section of the thick carbonate platform succession occurring at the base of the sedimentary cover in the southern Apennines. Our results bear major implication concerning the postulated occurrence of crustal faults allowing fluids to migrate directly from mantle depths to the surface

Exploring the Release of Toxic Oligomers from α-Synuclein Fibrils with Antibodies and STED Microscopy.

α-Synuclein (αS) is an intrinsically disordered and highly dynamic protein involved in dopamine release at presynaptic terminals. The abnormal aggregation of αS as mature fibrils into intraneuronal inclusion bodies is directly linked to Parkinson's disease. Increasing experimental evidence suggests that soluble oligomers formed early during the aggregation process are the most cytotoxic forms of αS. This study investigated the uptake by neuronal cells of pathologically relevant αS oligomers and fibrils exploiting a range of conformation-sensitive antibodies, and the super-resolution stimulated emission depletion (STED) microscopy. We found that prefibrillar oligomers promptly penetrate neuronal membranes, thus resulting in cell dysfunction. By contrast, fibril docking to the phospholipid bilayer is accompanied by αS conformational changes with a progressive release of A11-reactive oligomers, which can enter into the neurons and trigger cell impairment. Our data provide important evidence on the role of αS fibrils as a source of harmful oligomers, which resemble the intermediate conformers formed de novo during aggregation, underling the dynamic and reversible nature of protein aggregates responsible for α-synucleinopathies

The release of toxic oligomers from α-synuclein fibrils induces dysfunction in neuronal cells.

The self-assembly of α-synuclein (αS) into intraneuronal inclusion bodies is a key characteristic of Parkinson's disease. To define the nature of the species giving rise to neuronal damage, we have investigated the mechanism of action of the main αS populations that have been observed to form progressively during fibril growth. The αS fibrils release soluble prefibrillar oligomeric species with cross-β structure and solvent-exposed hydrophobic clusters. αS prefibrillar oligomers are efficient in crossing and permeabilize neuronal membranes, causing cellular insults. Short fibrils are more neurotoxic than long fibrils due to the higher proportion of fibrillar ends, resulting in a rapid release of oligomers. The kinetics of released αS oligomers match the observed kinetics of toxicity in cellular systems. In addition to previous evidence that αS fibrils can spread in different brain areas, our in vitro results reveal that αS fibrils can also release oligomeric species responsible for an immediate dysfunction of the neurons in the vicinity of these species

Relationships between geogenic radon potential and gamma ray maps with indoor radon levels at Caprarola municipality (central Italy)

Exposures to relatively high indoor radon (222Rn) levels represents a serious public health risk because Rn is associated with lung cancer (Darby et al., 2001; WHO, 2009; Oh et al., 2016; Sheen et al., 2016). The risk is high because radon, and its short-lived decay products in the atmosphere, contributes for about 60% of the total annual effective dose (UNSCEAR, 2000; WHO, 2009). Cancer risk is increased by smoking being almost 9 times higher than the risk to non-smokers exposed to similar levels (EPA, 2009). Due to these reasons, it is very important to assess the indoor exposure of public to radon and their daughters. Rn is a natural ubiquitous gas and its abundance is mainly controlled by the geology, and in particular by the soil and rock content of its parent nuclide (238U). Furthermore, bedrock characteristics (i.e. permeability and porosity) and also fault activity can affect the amount of Rn released in the ground (Ciotoli et al., 2007; Barnet et al., 2018). As such, in conditions of permeable and/or fractured bedrock and high uranium content, high indoor radon concentrations are expected (Bossew and Lettner, 2007; Gruber et al., 2013; Cinelli et al., 2015; Ielsch et al., 2017; Ciotoli et al., 2017). A non-natural contribution that controls the indoor Rn levels is home construction type and building materials (Vauptic et al., 2002; Appleton, 2007). Additionally, meteorological factors, such as wind, temperature and humidity, can affect the rate of Rn entry into the buildings (Porstendörfer et al., 1994; Miles et al., 2005; Schubert et al., 2018). In this work, we propose a new geospatial technique to construct the geogenic radon potential (GRP) map of the Caprarola municipality (northern Lazio, central Italy) characterized by recent (about 100 Kyr) volcanic deposits with high content in radon parent nuclides (Ciotoli et al., 2017). GRP map has been obtained by using Empirical Bayesian Kriging Regression (EBKR) technique with soil gas radon, as the response variable, and a number of proxy variables (i.e. content of the radiogenic parent nuclides, the emanation coefficient of the outcropping rocks, the diffusive 222Rn flux from the soil, the soil-gas CO2 concentration, the Digital Terrain Model (DTM), the permeability of the outcropping rocks and the gamma dose radiation of the shallow lithology. Furthermore, possible relationships between predicted soil radon values (i.e. GRP) and gamma radiation distribution with the indoor concentrations measured in private and public buildings has been investigated, respectively. The obtained results confirm that GRP maps provide the local administration of a useful tool for land use planning and that, the mapping of gamma emission, allows to a fast and effective evaluation of indoor radon hazard because it is mainly influenced by the building materials rather than other anthropic controls

A PM10 chemically characterised nation-wide dataset for Italy. Geographical influence on urban air pollution and source apportionment

: Urban textures of the Italian cities are peculiarly shaped by the local geography generating similarities among cities placed in different regions but comparable topographical districts. This suggested the following scientific question: can such different topographies generate significant differences on the PM10 chemical composition at Italian urban sites that share similar geography despite being in different regions? To investigate whether such communalities can be found and are applicable at Country-scale, we propose here a novel methodological approach. A dataset comprising season-averages of PM10 mass concentration and chemical composition data was built, covering the decade 2005-2016 and referring to urban sites only (21 cities). Statistical analyses, estimation of missing data, identification of latent clusters and source apportionment modelling by Positive Matrix Factorization (PMF) were performed on this unique dataset. The first original result is the demonstration that a dataset with atypical time resolution can be successfully exploited as an input matrix for PMF obtaining Country-scale representative chemical profiles, whose physical consistency has been assessed by different tests of modelling performance. Secondly, this dataset can be considered a reference repository of season averages of chemical species over the Italian territory and the chemical profiles obtained by PMF for urban Italian agglomerations could contribute to emission repositories. These findings indicate that our approach is powerful, and it could be further employed with datasets typically available in the air pollution monitoring networks