Popolamento umano ed evoluzione del paesaggio alle pendici del Mont Fallère (Saint-Pierre, Valle d'Aosta) nell’Olocene Antico e Medio

The present research aims at improving our knowledge on the way of life of prehistoric human groups on the Mont Fallère Massif and characterizing the main steps of the Holocene environmental history in this area. The importance of Men - Environment relationship is here highlighted thanks to a multidisciplinary and diachronic approach, typical of modern archaeology, based on a proper design beginning with an hypothesis and further evolving through subsequent steps of the research (Guidi, 2005). Fieldwork concentrated on the Mont Fallère area (municipality of Saint-Pierre, Aosta Valley) between 2009 - 2013, under the direction of Dip. Soprintendenza per i Beni e le Attività Culturali of Regione Autonoma Valle d'Aosta and the Ferrara University, which signed a specific agreement and carried out archaeological excavations and survey. Paleobotanical and geological investigations were carried out in the study area, too. Along with already-known sites MF1 to MF3, six new archaeological areas were discovered (named MF4 to MF9), scattered on an area of approximately 0,2 km2. Three sites (MF1, MF3 and MF6) were archaeologically investigated. Techno-economical and typological analysis of the lithic industries discovered at site MF1 was carried out, including experimental tests on methods and techniques used by prehistoric people to process rock crystals (D. Visentin), use-wear analysis on tools (G. Berruti) and the identification of procurement strategies of raw materials (S. Bertola). The CNR-IDPA Lab. of Palynology and Palaeoecology (Milano) carried out paleoecological investigations on the stratigraphic succession preserved at the Crotte Basse mire, located a few hundred meters far from the archeological sites. The collaboration with the Earth Science Dept. of the Torino University and the GDP Consultants - Engineering Geology Group in Aosta enabled geologically- geomorphologically-based researches on landscape evolution and the setting up of geomorphological and geophysical filters for a zonation of the study area with respect to the archeological visibility

XBT, ARGO Float and Ship-Based CTD Profiles Intercompared under Strict Space-Time Conditions in the Mediterranean Sea: Assessment of Metrological Comparability

open5noAccurate measurement of temperature and salinity is a fundamental task with heavy implications in all the possible applications of the currently available datasets, for example, in the study of climate changes and modeling of ocean dynamics. In this work, the reliability of measurements obtained by oceanographic devices (eXpendable BathyThermographs, Argo floats and Conductivity-Temperature-Depth sensors) is analyzed by means of an intercomparison exercise. As a first step, temperature profiles from XBT probes, deployed by commercial ships crossing the Ligurian and Tyrrhenian seas during the Ship of Opportunity Program (SOOP), were matched with profiles from Argo floats quasi-collocated in space and time. Attention was then paid to temperature/salinity profiling Argo floats. Since Argo floats usually are not recovered and should last up to five years without any re-calibration, their onboard sensors may suer some drift and/or oset. In the literature, refined methods were developed to post-process Argo data, in order to correct the response of their profiling CTD sensors, in particular adjusting the salinity drift. The core of this delayed-mode quality control is the comparison of Argo data with reference climatology. At the same time, the experimental comparison of Argo profiles with ship-based CTD profiles, matched in space and time, is still of great importance. Therefore, an overall comparison of Argo floats vs. shipboard CTDs was performed, in terms of temperature and salinity profiles in the whole Mediterranean Sea, under space-time matching conditions as strict as possible. Performed analyses provided interesting results. XBT profiles confirmed that below 100mdepth the accordance with Argo data is reasonably good, with a small positive bias (close to 0.05 °C) and a standard deviation equal to about 0.10 °C. Similarly, side-by-side comparisons vs. CTD profiles confirmed the good quality of Argo measurements; the evidence of a drift in time was found, but at a level of about E-05 unit/day, so being reasonably negligible on the Argo time-scale. XBT, Argo and CTD users are therefore encouraged to take into account these results as a good indicator of the uncertainties associated with such devices in the Mediterranean Sea, for the analyzed period, in all the climatological applications.openBordone, Andrea; Pennecchi, Francesca; Raiteri, Giancarlo; Repetti, Luca; Reseghetti, FrancoBordone, Andrea; Pennecchi, Francesca; Raiteri, Giancarlo; Repetti, Luca; Reseghetti, Franc

PRESERVATION OF QUATERNARY SEDIMENTS IN DSGSD ENVIRONMENTS: THE MONT FALLÈRE CASE STUDY (AOSTA VALLEY, NW ITALY)

Deep seated gravitational slope deformations (DSGSD) in the Western Alps, which usually affect glacial valleys, produce strong deformation in both bedrock and Quaternary cover, generally favouring erosion. This research, which examines a DSGSD along the Mont Fallère southern slope in the Aosta Valley, suggests that DSGSD can also locally favour the formation and preservation of the Quaternary stratigraphic successionns for the following reasons: - the development of transversal elongated depressions, which are essentially connected with the onset of gravitational structures (trenches, minor scarps, and counterscarps) and filled by differentiated Quaternary successions; - the occurrence of closed depressions along the slope, which originate from the gradual evolution of gravitational structures (trenches or minor scarps and associated counterscarps) and are occupied by lakes that are progressively filled by lacustrine and palustrine sequences; - the occurrence of wide, flat, irregular surfaces that are characterized by lower erosional phenomena with respect to the surrounding steep slopes and preserve various Quaternary stratigraphic successions; - the development of rounded reliefs and associated wide depressions, both of which exhibit topographic surfaces that hang over torrential incisions that are located along the main fractures; this morphology favours the preservation of glacial, outwash, lacustrine and palustrine sediments; - wide colluvial and debris cover that buries and partially preserves older Quaternary sediments; - the local occurrence of a travertine cover and carbonatie-cemented sediments, which preserve the older Quaternary sediments. These morphological conditions are favourable to prehistoric human settlements, resulting in archaeological mountain sites that also provide a chronological reference for the evolution of DSGSD

Enhanced Function and Overexpression of Metabotropic Glutamate Receptors 1 and 5 in the Spinal Cord of the SOD1G93A Mouse Model of Amyotrophic Lateral Sclerosis during Disease Progression

open10Glutamate (Glu)-mediated excitotoxicity is a major cause of amyotrophic lateral sclerosis (ALS) and our previous work highlighted that abnormal Glu release may represent a leading mechanism for excessive synaptic Glu. We demonstrated that group I metabotropic Glu receptors (mGluR1, mGluR5) produced abnormal Glu release in SOD1G93A mouse spinal cord at a late disease stage (120 days). Here, we studied this phenomenon in pre-symptomatic (30 and 60 days) and early-symptomatic (90 days) SOD1G93A mice. The mGluR1/5 agonist (S)-3,5-Dihydroxyphenylglycine (3,5-DHPG) concentration dependently stimulated the release of [3H]d-Aspartate ([3H]d-Asp), which was comparable in 30- and 60-day-old wild type mice and SOD1G93A mice. At variance, [3H]d-Asp release was significantly augmented in 90-day-old SOD1G93A mice and both mGluR1 and mGluR5 were involved. The 3,5-DHPG-induced [3H]d-Asp release was exocytotic, being of vesicular origin and mediated by intra-terminal Ca2+ release. mGluR1 and mGluR5 expression was increased in Glu spinal cord axon terminals of 90-day-old SOD1G93A mice, but not in the whole axon terminal population. Interestingly, mGluR1 and mGluR5 were significantly augmented in total spinal cord tissue already at 60 days. Thus, function and expression of group I mGluRs are enhanced in the early-symptomatic SOD1G93A mouse spinal cord, possibly participating in excessive Glu transmission and supporting their implication in ALS. Please define all abbreviations the first time they appear in the abstract, the main text, and the first figure or table caption.openTiziana Bonifacino, Claudia Rebosio, Francesca Provenzano, Carola Torazza, Matilde Balbi, Marco Milanese, Luca Raiteri, Cesare Usai, Ernesto Fedele, Giambattista Bonanno.Bonifacino, Tiziana; Rebosio, Claudia; Provenzano, Francesca; Torazza, Carola; Balbi, Matilde; Milanese, Marco; Raiteri, Luca; Usai, Cesare; Fedele, Ernesto; Bonanno, Giambattist

The transition from population III to population II-I star formation

We present results from the first cosmological simulations which study the onset of primordial, metal-free (population III), cosmic star formation and the transition to the present-day, metal-rich star formation (population II-I), including molecular (H$_2$, HD, etc.) evolution, tracing the injection of metals by supernov{\ae} into the surrounding intergalactic medium and following the change in the initial stellar mass function (IMF) according to the metallicity of the corresponding stellar population. Our investigation addresses the role of a wide variety of parameters (critical metallicity for the transition, IMF slope and range, SN/pair-instability SN metal yields, star formation threshold, resolution, etc.) on the metal-enrichment history and the associated transition in the star formation mode. All simulations present common trends. Metal enrichment is very patchy, with rare, unpolluted regions surviving at all redshifts, inducing the simultaneous presence of metal-free and metal-rich star formation regimes. As a result of the rapid pollution within high-density regions due to the first SN/pair-instability SN, local metallicity is quickly boosted above the critical metallicity for the transition. The population III regime lasts for a very short period during the first stages of star formation ($\sim 10^7\,\rm yr$), and its average contribution to the total star formation rate density drops rapidly below $\sim 10^{-3}-10^{-2}$

Multiwavelength observations of 3C 454.3. I. The AGILE 2007 November campaign on the "Crazy Diamond"

[Abridged] We report on a multiwavelength observation of the blazar 3C 454.3 (which we dubbed "crazy diamond") carried out on November 2007 by means of the astrophysical satellites AGILE, INTEGRAL, Swift, the WEBT Consortium, and the optical-NIR telescope REM. 3C 454.3 is detected at a $\sim 19-\sigma$ level during the 3-week observing period, with an average flux above 100 MeV of $F_{\rm E>100MeV} = (170 \pm 13) \times 10^{-8}$ \phcmsec. The gamma-ray spectrum can be fit with a single power-law with photon index $\Gamma_{\rm GRID} = 1.73 \pm 0.16$ between 100 MeV and 1 GeV. We detect significant day-by-day variability of the gamma-ray emission during our observations, and we can exclude that the fluxes are constant at the 99.6% ($\sim 2.9 \sigma$) level. The source was detected typically around 40 degrees off-axis, and it was substantially off--axis in the field of view of the AGILE hard X-ray imager. However, a 5-day long ToO observation by INTEGRAL detected 3C 454.3 at an average flux of about $F_{\rm 20-200 keV} = 1.49 \times 10^{-3}$ \phcmsec with an average photon index of $\Gamma_{\rm IBIS} = 1.75 \pm 0.24$ between 20--200 keV. Swift also detected 3C 454.3 with a flux in the 0.3--10 keV energy band in the range $(1.23-1.40) \times 10^{-2}$ \phcmsec{} and a photon index in the range $\Gamma_{\rm XRT} = 1.56-1.73$. In the optical band, both WEBT and REM show an extremely variable behavior in the $R$ band. A correlation analysis based on the entire data set is consistent with no time-lags between the gamma-ray and the optical flux variations. Our simultaneous multifrequency observations strongly indicate that the dominant emission mechanism between 30 MeV and 30 GeV is dominated by inverse Compton scattering of relativistic electrons in the jet on the external photons from the broad line region.Comment: Accepted for publication in ApJ. Abridged Abstract. 37 pages, 14 Figures, 3 Table