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Background: Primary Hypobetalipoproteinemias (HBL) are a group of dominant and recessive monogenic genetic disorders caused by mutations in APOB, PCSK9, ANGPTL3, MTTP, Sar1b genes and characterized by plasma levels of total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and apolipoprotein B (apoB) below the 5th percentile of the distribution in a given population. Mutations in the candidate genes account only for a small proportion of subjects with HBL suggesting a role for a polygenic contribution to the low cholesterol phenotype. Objective: To explore the complex genetic architecture of HBL we compared two polygenic risk scores in order to assess the role of the polygenic burden and the differences in the clinical phenotype between monogenic and polygenic HBL; we studied a cohort of 170 subjects with primary HBL referred over a 25-year period to 2 Italian reference centers have been studied. Methods: The genetic analyses have been based on: Sanger sequencing, in-house NGS customized panel and two scores, PRS1 and PRS2 for the polygenic burden. Results: Sixty 60 (35%) and 63 (37%) subjects had a monogenic and polygenic HBL respectively. LDL-C plasma levels were significantly lower in monogenic HBL (30.87 ± 3.12 mg/dl) compared with the non-monogenic HBL (42.80 ± 2.18 mg/dl) (p

Partitioning experiments between a basaltic melt from Mt. Etna and a low-density hydrous fluid or vapor containing H2O or H2O–CO2 were performed at 1200–1260 °C, at pressures between 1 and 200 MPa, either near the nickel–nickel oxide (NNO) buffer or at two log units above it (NNO+2), and with different chloride concentrations. Most of the experiments were done at chloride-brine-undersaturated conditions, although at the highest Cl concentrations explored brine saturation might have been reached. The average partition coefficients (DCl fluid/melt) over the range of Cl concentrations were derived on a weight basis by plotting the calculated concentrations of Cl in the fluid phase versus the measured ones in the melt. For H2O–Cl experiments in which the Cl concentration in the melt was ≤0.4 wt.%, a negative dependence between DClf/m and pressure is observed. DClfluid/melt in H2O+Cl-bearing experiments ranges between 11–14 at 1 and 25 MPa to 6 at 200 MPa at NNO; and between 4 at 50 MPa and 13 at 100 MPa at ΔNNO≥2. Addition of CO2 at NNO yields lower partition coefficients than in CO2-free conditions over the pressure range investigated. The negative pressure dependence observed for H2O–Cl experiments disappears when CO2 is present in the system. Overall, once CO2 is introduced in the system, Cl fugacity in the silicate melt tends to increase, thus resulting in a decrease of DCl f/m. Application to Mt. Etna shows that the composition of the volcanic plume in terms of Cl records very shallow pressures of magma equilibration with its exsolved fluid.

Partitioning of halogens between gas and basaltic melts at 1200-1265°C and 10-2000 bar (Alletti, 2008) has been analyzed in detail by means of the CTSFG model (Moretti and Ottonello, 2005) in order to: 1) evaluate redox conditions consistent with related experimental information such as PH2 and S2−/S6+ ratio, 2) estimate the relative abundance of H2O, CO2, KCl, NaCl and HCl of the gas phase, 3) investigate the solubility mechanisms of chlorine and fluorine in (basaltic) melts. For chlorinebased runs, it was found that for input [Na+K]/Cl atom ratios > 0.45 the proportion of gaseous NaCl and KCl exceeds that of HCl. In terms of solubility mechanisms, halogen chemical reactivity can be assessed in terms of dissolution into the melt as chloride or fluoride ion, i.e, Cl− and F−. A complementary solubility mechanism can be invoked to improve the precision and explain somehow unexpected features, such as i) a P-independent background values of halogen solubility, and, for chlorine only, ii) a XCl,melt-squareddependence shown by Cl dissolution. In this additional mechanism, undissociated alkali-halogenides dissolve in the melt up to a solubility limit which depends on structural conditions, i.e. on melt composition for the same T. Although this could be a fascinating hypothesis, somehow recalling the concentration limits of Henry’s law behavior for trace element dissolution into minerals, it is then questioned whether this may reflect or not mixing of a molten salt-like component with the silicate melt. Partition coefficients derived from equilibrium constants of reactions involving Cl− and F− show well the role of water vapor as stripping agent of chlorine. Therefore, the more the CO2 in the system, the more the amount of chlorine getting dissolved into the melt phase.

Despite the importance of halogens (F, Cl) in volcanic degassing, solubility and fluid/melt partitioning of these elements have not been comprehensively studied in natural basaltic melts. Experimental determinations of halogen solubility in Mount Etna melts are lacking, despite this volcano being one of the most active and intensively monitored on Earth with an estimated output of thousands tonnes of halogens per day. In order to better understand halogen degassing, we present the results of a series of halogen partitioning experiments performed at different pressures (1-200 MPa), redox conditions (from Δ NNO = + 2 to Δ NNO = - 0.3) and fluid compositions. Experiments used a hawaiitic, glassy, alkaline basalt with Mg# = 0.59, sampled during the July 2001 eruption of Mount Etna. A series of experiments were conducted using H2O-NaCl or H2O-NaF solutions. The effect of CO2 in multi-component fluid H2O-CO2-NaCl or H2O-CO2-NaF was also investigated. The experimental run products were mostly glasses, but a few run products contained less than 10% crystals. The concentration of halogens in the fluid phase after the experiment was calculated from mass balance, and the partition coefficients for both Cl and F at the studied conditions determined. Using these measurements and thermodynamical models, the dependence of these partition coefficients on the fugacities of various gaseous species was investigated.

International audience; Viscosity (η), glass transition (Tg) and heat capacity (Cp) of Etna trachybasalt and Fondo Riccio latite (Phlegrean Fields, Italy) were determined at low and high temperature for dry, hydrous and CO2 bearing samples. High temperature experiments have been performed in the range of 1499 to 1700 K by concentric cylinder measurements, while low temperature experiments were carried out in the interval between 633 and 1093 K using the micropenetration technique. Glass transition temperature, glassy and liquid heat capacities were investigated using differential scanning calorimetry (DSC) up to 955 K. The H2O content in the melts ranged from nominally dry to 6.32 wt%, while CO2 ranged from 229 to 1907 ppm. We combined low- and high-temperature viscosities and parameterized them by the use of a modified Vogel-Fulcher-Tamman equation, which accommodates the non-Arrhenian temperature dependence of melt viscosity. Experimental measurements show that melt viscosity decreases with increasing temperature, water and CO2 content. For latitic samples at 893 K, the introduction of CO2 (up to 732 ppm) decreases the liquid viscosity up to one order of magnitude with respect to the measured viscosity for H2O-bearing liquid. Moreover, the results of calorimetric measurements indicate that the glass transition temperature decreases with increasing volatiles content (H2O + CO2). The glass transition temperature decreases by about 25 K by adding up to 1907 ppm of CO2 in the trachybasaltic samples. No appreciable effect on glassy [Cpg (Tg)] and liquid (Cpliq) heat capacity was observed with the addition of water and CO2. Structural and volcanological implication (i.e. volatiles speciation and melt fragility) for water and CO2 dissolution in silicate melts are discussed in light of the presented results.

Partitioning experiments between a basaltic melt from Mt. Etna and a low-density hydrous fluid or vapor containing H(2)O or H(2)O-CO(2) were performed at 1200-1260 degrees C, at pressures between 1 and 200 MPa, either near the nickel-nickel oxide (NNO) buffer or at two log units above it (NNO + 2), and with different chloride concentrations. Most of the experiments were done at chloride-brine-undersaturated conditions, although at the highest Cl concentrations explored brine saturation might have been reached. The average partition coefficients (D(Cl)(fluid/melt)) over the range of Cl concentrations were derived on a weight basis by plotting the calculated concentrations of Cl in the fluid phase versus the measured ones in the melt. For H(2)O-Cl experiments in which the Cl concentration in the melt was = 2. Addition of CO(2) at NNO yields lower partition coefficients than in CO(2)-free conditions over the pressure range investigated. The negative pressure dependence observed for H(2)O-Cl experiments disappears when CO(2) is present in the system. Overall, once CO(2) is introduced in the system, Cl fugacity in the silicate melt tends to increase, thus resulting in a decrease of D(Cl)(f/m). Application to Mt. Etna shows that the composition of the volcanic plume in terms of Cl records very shallow pressures of magma equilibration with its exsolved fluid.

Ustica Island, southern Tyrrhenian Sea, is constituted of Quaternary alkaline volcanics. Avariety of enclaves representative of deep to supra-crustal settings were recently found in a hawaiitic lava flow. Enclaves consist of: (i) Ultramafic meta-cumulates, i.e. clinopyroxenites and wherlites characterized by variably deformed porphyroclastic to granoblastic textures. (ii) Mafic cumulates, i.e. gabbros (F amphibole) and troctolites, the first often characterized by frequent amphibole breakdown coronas (olivine+Tiaugite+ plagioclase+magnetite+ilmenite+rhfnite) in response to an H2O decrease during the ascent, while the troctolites interpreted as meta-cumulates. (iii) Microsyenites, consist of anorthoclase and Fe-clinopyroxene organized in a granular subipidiomorphic texture. Amphibole is absent in Ustica lavas and is found only in some old, now exposed, sub-intrusive volcanic bodies. This evidence suggests a late appearance of amphibole on the liquidus, at a high crystal content that inhibits further ascent of the magma. The importance of the amphibole as a medium pressure liquidus phase in Ustica mafic magmas is in the bearings on the geochemistry of lavas e.g. in buffering Na and Ti abundances, in trace elements partitioning, etc. Density measurements pointed out higher values for clinopyroxenites (3160 to 3300 kg/m3) than for gabbros (ca. 2900 kg/ m3). Given the density contrast between enclaves and host lavas (2790 kg/m3) and assuming appropriate rheological models, we calculated a minimum ascent rate of 0.01 m/s, corresponding to an ascent time in the range of 5–29 days for a depth of entrapment of 25 km.