Population Data for Y-Chromosome Haplotypes Defined by AmpFlSTR YFiler PCR Amplification Kit in North Sardinia (Italy)

The 17 Y-chromosomal short tandem repeats (STRs) included in the AmpFlSTR YFiler Amplification Kit (AB Applied Biosystems) (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4.1) were typed in 100 samples from North Sardinia (Italy). A total of 91 different haplotypes were found, where 9 haplotypes were shared by two individuals. The overall haplotype diversity (HD) was 0.9982. DYS458 non-consensus alleles were found in one samples, and one in the DYS438. We found a double peak in one sample for the DYS19 with alleles 15/16. Population comparisons with available 10 YSTR loci data in Mediterranean Basin samples were undertaken, significant differences were observed between our sample and all the compared populations, except for a entire sample from Sardinia. Prediction of haplogroups showed I2a1 was found to be the most frequent haplogroup (33%) in our sample. Testing high-resolution Y-chromosome data sets it is useful in autochthonous population and micro-population studies to highlight the most informative loci for evolutionary aims

Calibrating Carbonization Temperatures of Wood Fragments Embedded within Pyroclastic Density Currents through Raman Spectroscopy

The Grant of Excellence Departments, MIUR (ARTICOLO 1, COMMI 314–337 LEGGE 232/2016) is gratefully acknowledged. MathWorks is acknowledged for providing the Matlab license for this work. A version of the script for calculating temperatures from Raman spectra can be provided by the authors upon request. This research was funded by an MIUR Roma Tre post-doctoral grant (2017–20) No. REP. 22-PROT. 219 of 26 January 2017.Peer reviewedPublisher PD

Effect of iron and nanolites on Raman spectra of volcanic glasses:A reassessment of existing strategies to estimate the water content

Global peatlands are a valuable but vulnerable resource. They represent a significant carbon and energy reservoir and play major roles in water and biogeochemical cycles. Peat soils are highly complex porous media with distinct characteristic physical and hydraulic properties. Pore sizes in undecomposed peat can exceed 5 mm, but significant shrinkage occurs during dewatering, compression and decomposition, reducing pore-sizes. The structure of peat soil consists of pores that are open and connected, dead-ended or isolated. The resulting dual-porosity nature of peat soils affects water flow and solute migration, which influence reactive transport processes and biogeochemical functions. Advective movement of aqueous and colloidal species is restricted to the hydrologically active (or mobile) fraction of the total porosity, i.e. the open and connected pores. Peat may attenuate solute migration through molecular diffusion into the closed and dead-end pores, and for reactive species, also through sorption and degradation reactions. Slow, diffusion-limited solute exchanges between the mobile and immobile regions may give rise to pore-scale chemical gradients and heterogeneous distributions of microbial habitats and activity in peat soils. While new information on the diversity and functionalities of peat microbial communities is rapidly accumulating, the significance of the geochemical and geomicrobial study on peat stands to benefit from a basic understanding of the physical structure of peat soils. In this paper, we review the current knowledge of key physical and hydraulic properties related to the structure of globally available peat soils and briefly discuss their implications for water storage, flow and the migration of solutes. This paper is intended to narrow the gap between the ecohydrological and biogeochemical research communities working on peat soils

A chemical threshold controls nanocrystallization and degassing behaviour in basalt magmas

An increasing number of studies are being presented demonstrating that volcanic glasses can be heterogeneous at the nanoscale. These nano-heterogeneities can develop both during viscosity measurements in the laboratory and during magma eruptions. Our multifaceted study identifies here total transition metal oxide content as a crucial compositional factor governing the tendency of basalt melts and glasses towards nanolitization: at both anhydrous and hydrous conditions, an undercooled trachybasalt melt from Mt. Etna readily develops nanocrystals whose formation also hampers viscosity measurements, while a similar but FeO- and TiO2-poorer basalt melt from Stromboli proves far more stable at similar conditions. We therefore outline a procedure to reliably derive pure liquid viscosity without the effect of nanocrystals, additionally discussing how subtle compositional differences may contribute to the different eruptive styles of Mt. Etna and Stromboli

Population Data for Y-Chromosome Haplotypes Defined by AmpFlSTR YFiler PCR Amplification Kit in North Sardinia (Italy)

The 17 Y-chromosomal short tandem repeats (STRs) included in the AmpFlSTR YFiler Amplification Kit (AB Applied Biosystems) (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4.1) were typed in 100 samples from North Sardinia (Italy). A total of 91 different haplotypes were found, where 9 haplotypes were shared by two individuals. The overall haplotype diversity (HD) was 0.9982. DYS458 non-consensus alleles were found in one samples, and one in the DYS438. We found a double peak in one sample for the DYS19 with alleles 15/16. Population comparisons with available 10 YSTR loci data in Mediterranean Basin samples were undertaken, significant differences were observed between our sample and all the compared populations, except for a entire sample from Sardinia. Prediction of haplogroups showed I2a1 was found to be the most frequent haplogroup (33%) in our sample. Testing high-resolution Y-chromosome data sets it is useful in autochthonous population and micro-population studies to highlight the most informative loci for evolutionary aims

High Differentiation among Eight Villages in a Secluded Area of Sardinia Revealed by Genome-Wide High Density SNPs Analysis

To better design association studies for complex traits in isolated populations it's important to understand how history and isolation moulded the genetic features of different communities. Population isolates should not “a priori” be considered homogeneous, even if the communities are not distant and part of a small region. We studied a particular area of Sardinia called Ogliastra, characterized by the presence of several distinct villages that display different history, immigration events and population size. Cultural and geographic isolation characterized the history of these communities. We determined LD parameters in 8 villages and defined population structure through high density SNPs (about 360 K) on 360 unrelated people (45 selected samples from each village). These isolates showed differences in LD values and LD map length. Five of these villages show high LD values probably due to their reduced population size and extreme isolation. High genetic differentiation among villages was detected. Moreover population structure analysis revealed a high correlation between genetic and geographic distances. Our study indicates that history, geography and biodemography have influenced the genetic features of Ogliastra communities producing differences in LD and population structure. All these data demonstrate that we can consider each village an isolate with specific characteristics. We suggest that, in order to optimize the study design of complex traits, a thorough characterization of genetic features is useful to identify the presence of sub-populations and stratification within genetic isolates

Multiphase rheology of Italian alkaline magmas

As a step towards the characterization of the rheological properties of natural magmatic mixtures a detailed experimental investigation on natural sample derived from Italian Volcanic systems ( Stromboli, Etna and Phlegrean Fields) has been performed. Viscosity measurements were conducted on basaltic melts from Stromboli and Etna during their crystallization. At the investigated subliquidus temperatures ( 1131°C < T < 1187°C), a strong increase in viscosity due the presence of crystals (ϕ=0.06-0.27) was observed. At T > 1175°C and ϕ up to 0.12-0.14 both studied compositions behave as Newtonian, while with decreasing temperature, the increase in crystal content leads to the onset of a weak shear thinning behavior (n=0.9). A strong departure from the well-known (strain-rate independent) Einstein-Roscoe equation and from the strain-rate dependent model developed by Costa et al. (2009) has been observed. The origin of this departure is related primarily to the effect of elongated plagioclase in increasing crystal interactions at low ϕ. Detailed textural analyses allowed to develop for the first time on natural liquids a parameterization of the multiphase rheology, which takes into account the crystal shape, crystal size distribution of the suspension and the deformation regime. The results were applied to a synthetic suspension HPG8Na20 containing a variable amount of almost spherical corundum particles with known textural features at T=1000-1100 °C. Multiphase rheology of natural vesicles- and crystal- bearing magmas from Monte Nuovo have been investigated by uniaxial deformation experiments in the T range 600°C-800°C and strain rates between 10-7 and 10-4 s-1. Brittle behavior of the magma has been observed at T<600°C and strain rates of 10-5 s-1 and at T=800°C for the higher applied strain rate (10-4 s-1). All other experiments were performed in the viscous regime and Monte Nuovo magma showed always a non-Newtonian shear thinning behavior. Effective viscosity in the range of 1010-1013 were calculated by the no slip model by Gent (1960). Fitting of experimental data using the Herschel-Bulkley model revealed that at the studied condition, no yield stress was present and yielded a parametrization of the flow behavior in terms of consistency K and flow index n. The relative viscosities indicated a dependence from experimental temperature and applied strain rate. Higher relative viscosities (up to 2.1 log10 units) were observed with increasing temperature and decreasing strain rates. Negative relative viscosities were observed at T=640°C, when the melt approaches the glass transition temperature (Giordano et al., 2005). To derive the net effect of vesicles on the rheology of Monte Nuovo magmas, the relative viscosity was further normalized to the relative viscosity obtained by Caricchi et al. (2008) on the same sample composition and no porosity. Normalization revealed that the presence of vesicles has a major influence on the rheology of magmas and can lead to a decrease of the viscosity of more than two orders of magnitude. Viscosity measurements have been performed on basaltic melts from Etna at low oxygen fugacity conditions and T between 1150°C-1300°C. Reducing conditions yield a slight decrease in viscosity compared to the expected viscosity versus temperature relationship at fO2 = air (Giordano and Dingwell 2003). Moreover, another effect of lowering the oxygen fugacity conditions is the decrease of liquidus temperature of the melt which leads to none or minor crystallization compared to experiments conducted at fO2=air. The results of two experiments conducted at two different oxidation state at T=1300°C (Fe3+/ΣFe = 0.18 and 0.76, respectively) indicated that the viscosity decrease observed as an inverse function of fO2, is smaller than what observed by many authors on simplified iron-bearing silicate melts. We suggest that this behavior is linked to the competition in natural systems between Fe3+ and Al3+ for the tetrahedric structural sites. Being Al favored in tetrahedrical coordination, part of Fe3+ is forced to behave as network-modifier also at high fugacity condition, thus the depolymerization of the melt when the reduction Fe3+- Fe2+ takes place is limited. Our data seem to be consistent with those obtained by Bouhifd et al. (2004) on basalts, confirming that the effect of oxidation state on viscosity is more pronounced at lower than at higher temperatures and for Al-free synthetic liquids rather than for natural melts. Rheological measurements conducted on basaltic melts from Stromboli and Etna at subliquidus conditions (see above) were also used to investigate the effect of the deformation rate (gammai=4.26 s-1 for Stromboli and gammai=0.53 s-1 for Etna) on the crystallization kinetics of plagioclase at different degree of undercooling (ET), varying from 24 to 45°C for Stromboli and from 21 to 72°C for Etna. Post-run plagioclase crystal contents are between ϕ=0.11-0.23 for Stromboli and between ϕ=0.06-0.18 for Etna with increasing undercooling. Different kinetics of the crystallization process has been observed. Higher deformation rates seem to play a fundamental role in favoring the achievement of phase equilibria in a short time-scale. Crystal Size Distribution (CSD) of the experimental plagioclase crystals are always characterized by a log-linear decrease of population density as a function of crystal size. With increasing degree of undercooling a systematic increase of the steepness of the curves has been observed for both datasets. The CSD parameter of all samples (slopes and intercept) are linearly correlated with the overall crystal content. However, given the difference of the crystal content vs. undercooling behavior for the two datasets, two different linear correlation have been found for Stromboli and Etna, relating the CSD parameters to the degree of undercooling. In the framework of the CSD theory average value of G and average J were obtained. Stromboli data always show higher values of both G and J with respect to Etna data. Stromboli growth rates G are quite stable with increasing undercooling, however they display a relative small variation ranging between 2.5-3 x10-8 m/s. A slight increase of G can be observed for Etna with decreasing temperature, from 0.6 x 10-8 to 1.3 x 10-8 m/s. Nucleation rates J always continuously increase with undercooling from 1.3 x 107 to 8.72 x 107 m.3 s-1 for Stromboli and for Etna (9.2 x 104 m.3 s-1 - 2.9 x 107 m.3 s-1). However, the lowest value of J for Etna is relative to a sample in which evidence of textural coarsening have been observed and hence it represents a minimum value. Data obtained for G and J in this study are comparable with those obtained in literature, both from natural samples and from experimental studies. Data from this study can be applied to natural volcanic system to take into account the effect of deformation rate on the variation of crystallization kinetics. G and J data obtained in this work can be applied to natural volcanic system to infer residence times in magma chambers and magma ascent velocities. This work underline also the need and the importance to consider the deformation rates in the variation of the crystallization kinetics