ALBERT

Description: In 2015, we have collected more than 60,000 scavenging amphipod specimens during two expeditions to the Clarion-Clipperton fracture Zone (CCZ), in the Northeast (NE) Pacific and to the DISturbance and re-COLonisation (DisCOL) Experimental Area (DEA), a simulated mining impact disturbance proxy in the Peru basin, Southeast (SE) Pacific. Here, we compare biodiversity patterns of the larger specimens (〉15mm) within and between these two oceanic basins. Nine scavenging amphipod species are shared between these two areas, thus indicating connectivity. We further provide evidence that disturbance proxies seem to negatively affect scavenging amphipod biodiversity, as illustrated by a reduced alpha biodiversity in the DEA (Simpson Index (D)=0.62), when compared to the CCZ (D=0.73) and particularly of the disturbance site in the DEA and the site geographically closest to it. Community compositions of the two basins differs, as evidenced by a Non-Metric Dimensional Scaling (NMDS) analysis of beta biodiversity. The NMDS also shows a further separation of the disturbance site (D1) from its neighbouring, undisturbed reference areas (D2, D3, D4 and D5) in the DEA. A single species, Abyssorchomene gerulicorbis, dominates the DEA with 60% of all individuals.

Description: Parce que le contrat, polymorphe, irrigue de nombreux pans du droit, parce que le contrat, international, transcende les limites géographiques, l’idée d’un colloque jouant sur « Le contrat dans tous ses États » s’est imposée à ses deux organisatrices. Le caractère transfrontalier du contrat et la multiplication des échanges interétatiques rendent essentielle la problématique du conflit de lois et du conflit de juridictions, donc la thématique du droit international privé. Cette dernière a été abordée dans toute sa diversité, du droit des obligations stricto sensu, en passant par les questions familiales, sans oublier le droit du travail et les mécanismes perturbateurs au premier rang desquels les lois de police. L’internationalité ne pouvait laisser de côté la nécessaire approche comparatiste des contrats. Plusieurs réflexions de droit comparé français et anglais sont menées, car le droit continental et la Common law s’opposent traditionnellement et parce que l’actualité juridique des deux côtés de la Manche (la réforme du droit français du contrat ainsi que les négociations post-Brexit notamment) invite le juriste à s’interroger sur les influences de chacun : aussi est-il question de l’influence britannique sur les remèdes français à l’inexécution du contrat, ainsi que celle qui pourrait enrichir la clause de force majeure dans le droit français. Les interactions anglaises et françaises de la bonne foi dans les contrats au regard du pouvoir discrétionnaire du juge sont également envisagées. Ces réflexions sont prolongées par une analyse de la bonne foi dans le droit français du contrat, et, enfin, par une approche comparée du contrat dans le droit de la famille.

Description: It is well known that, in classification problems, the predictive capacity of any decision-making model decreases rapidly with increasing asymmetry of the target variable (Sonquist et al., 1973; Fielding 1977). In particular, in segmentation analysis with a categorical target variable, very poor improvements of purity are obtained when the least represented modality counts less than 1/4 of the cases of the most represented modality. The same problem arises with other (theoretically more exhaustive) techniques such as Artificial Neural Networks. Actually, the optimal situation for classification analyses is the maximum uncertainty, that is, equidistribution of the target variable. Some classification techniques are more robust, by using, for example, the less sensitive logit transformation of the target variable (Fabbris & Martini 2002); however, also the logit transformation is strongly affected by the distributive asymmetry of the target variable. In this paper, starting from the results of a direct survey in which the target (binary) variable was extremely asymmetrical (10% vs. 90%, or greater asymmetry), we noted that also the logit model with the most significant parameters had very reduced fitting measures and almost zero predictive power. To solve this predictive issue, we tested post-stratification techniques, artificially symmetrizing a training sample. In this way, a substantially increase of fitting and predictive capacity was achieved, both in the symmetrized sample and, above all, in the original sample. In conclusion of the paper, an application of the same technique to a dataset of very different nature and size is described, demonstrating that the method is stable even in the case of analysis executed with all data of a population.

Description: The application of Precision Agriculture strategies represents an opportunity for farmers to obtain economic benefits. In the area of Metapontino, as demonstrated by the experimentation conducted, the challenge of producing food and at the same time protecting nature and safeguarding biodiversity, it is possible to face it through the introduction of global positioning systems (GPS), a technology capable of integrating the information on soil type, climate, cultivar, crop and farm management, topography and economy.

Description: The seismic characterization of monitoring sites is a fundamental step in any study dealing with the estimation of site effects. The correct assessment of local amplification is also important in the definition of hazard maps, in order to taking into account the possible role of site effects in modifying the ground motion recording with respect to an ideal bedrock site. In the framework of the activity between Department of Civil Protection (DPC) and Istituto Nazionale di Geofisica e Vulcanologia (INGV) (DPC-INGV 2012-202, Allegato B2, Obiettivo 1, Task B), a campaign of site characterization started in 2016 for the estimation of the seismic response at some stations belonging to the National Accelerometric Network (RAN) and to National Seismic Network (RSN). The accelerometric data of these stations are collected in the ITACA database (Pacor et al. 2011) and in a structured archive managed by INGV (please refer to Bordoni et al. in session 2.1 of this conference). In this work, we focus on five seismic stations (CMP0, CDCA, ROM9, SANR, LAV9) installed in a different geological context. We show the strategy adopted for assessing the geological setting and velocity profile below the site and in the estimation of the soil class category. CMPO, SANR and CDCA are situated in alluvial environment (Reno Alluvial Plain, Veneto-Friuli Plain, Alto-Tiber plain, respectively) where the soft deposits show significant thickness (〉 100 m), whereas ROM9 and LAV9 are characterized by the presence of volcanic deposits belonging to the Colli Albani hills. At ROM9 the thickness of the volcanic deposits is the order of 50 meters, at LAV9 the thickness is larger (〉 100 m). As first step, a conceptual model has been derived by geological field surveys and collecting the available geological information (scientific agreement between ISPRA and INGV). The results of this step are basically 2D geological models and a lithostratigraphic and lithotechnical classification of the outcropping units. Further, a geophysical survey at each site was carried out using surface-wave methods. We deployed 2D arrays of seismic three-components stations recording ambient vibration (or ambient seismic noise) in proximity of the target site to measure the dispersion curve following the recent guidelines (Foti et al, 2017). Passive 2D arrays recorded ambient noise for a total duration of some hours at each site. The array geometry was defined according to the logistic, and when possible two geometries with a progressive larger aperture were used at a same site (Fig. 1). The maximum aperture of the 2D arrays varies approximately from 100 to 400 m using a number of seismic stations from 8 to 14 depending on the site. At LAV9 site, we combined passive 2D array with a linear array of geophones equally spaced and using an active source (a weight body of 50 kg falling down from a height of about 2 m). Frequency-wavenumber and spatial auto-correlation methods derive a dispersion curve (Fig. 2). The inversion of the dispersion curves jointly with the horizontal-to-vertical spectral ratio (H/V curve) provides the local shear-wave velocity (Vs) profile. The soil class was finally assigned computing the mean value of the shear-wave best velocity models in the uppermost 30 m (as prescribed by the national seismic design code). As example, Fig. 3 displays the comparison at ROM9 between the local Vs profile derived from surface-wave analysis and the lithostratigraphical log obtained from the geological analysis. The Vs profile of ROM9 is able to individuate the contact at a depth of about 50 m between the volcanic deposits and the underlying clay (Monte Vaticano Unit, Pliocene). In detail from top to bottom in the velocity model of Fig. 3: after few meters of very soft soil (Vs 〈 200 m/s), the volcanic deposits show Vs values of 400-500 m/s, whereas the consolidated clay of the Monte Vaticano Formation shows Vs values larger than 600 m/s. The Vs30 at ROM9 resulting from this model is 410 m/s, being B the corresponding soil class category following the national code. As general comment resulting from this experience, a correct use of the surface-wave methods integrated with geological data is able to provide a reliable Vs profile that can be used to include the local effects in the seismic response of the site. However, it is important to highlight that we do not obtain always a perfect match between dispersion curves derived at a same site when we used different array geometry and source. The reasons of these discrepancies are not clear and need deeper investigation. A final consideration is that a suitable site classification is possible only with accurate geological and geophysical surveys. In presence of a reliable estimation of the local velocity profiles at the sites where seismic stations are installed, strong-motion data can be properly used for seismic hazard and site response studies.

Description: Published

Description: Trieste, Italy

Description: 4T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: 1SR. TERREMOTI - Servizi e ricerca per la Società

Description: 1IT. Reti di monitoraggio

Description: 4IT. Banche dati

Description: Tidal wetlands, such as tidal marshes and mangroves, are hotspots for carbon sequestration. The preservation of organic matter (OM) is a critical process by which tidal wetlands exert influence over the global carbon cycle and at the same time gain elevation to keep pace with sea-level rise (SLR). The present study provides the first global-scale field-based experimental evidence of temperature and relative sea level effects on the decomposition rate and stabilization of OM in tidal wetlands. The study was conducted in 26 marsh and mangrove sites across four continents, utilizing commercially available standardized OM. While effects on decomposition rate per se were minor, we show unanticipated and combined negative effects of temperature and relative sea level on OM stabilization. Across study sites, OM stabilization was 29 % lower in low, more frequently flooded vs. high, less frequently flooded zones. OM stabilization declined by ~ 90 % over the studied temperature gradient from 10.9 to 28.5 °C, corresponding to a decline of ~ 5 % over a 1 °C temperature increase. Additionally, data from the long-term ecological research site in Massachusetts, US show a pronounced reduction in OM stabilization by 〉 70 % in response to simulated coastal eutrophication, confirming the high sensitivity of OM stabilization to global change. We therefore provide evidence that rising temperature, accelerated SLR, and coastal eutrophication may decrease the future capacity of tidal wetlands to sequester carbon by affecting the initial transformations of recent OM inputs to soil organic matter.

Description: In the North Ionian, water circulation is characterized by a decadal alternation of cyclonic and anticyclonic regime driven by the mechanism called BiOS (Bimodal Oscillating System). The circulation regime affects the vertical dynamics and the nutrient distribution. The North Ionian is then a good study area to investigate how changes in circulation can affect phytoplankton dynamics in oligotrophic regions. From in situ observations, for each circulation regime the averaged distribution of isopycnals is provided, and a depth difference of about 80 m is estimated for the nitracline between cyclonic and anticyclonic regime. Based on phytoplankton phenology metrics extracted from annual time-series of satellite ocean color data for the period 1998–2012, the cyclonic and anticyclonic regimes are compared. Results show that the average chlorophyll in March, the date of bloom initiation and the date of maximum chlorophyll were affected by circulation patterns in the North Ionian. In the center of the gyre, bloom initiation occurred in December and chlorophyll was low in March when circulation was anticyclonic, whereas during the cyclonic circulation regime, a late chlorophyll peak, likely resulting from different phytoplankton dynamics, was commonly observed in March. An additional analysis shows that the winter buoyancy losses, which govern the Mixed Layer Depth (MLD) also contribute to explain the interannual variability in bloom initiation and intensity. Two scenarios involving the relative position of the MLD and nitracline are finally developed, discussed and tested with model data to explain the different phenology patterns observed in the North Ionian.

Description: Subpolar regions in the southern hemisphere are influenced by the Antarctic polar vortex during austral spring, which induces high and short term ozone variability at different altitudes mainly into the stratosphere. This variation may affect considerably the total ozone column changing the harmful UV radiation that reaches the surface. With the aim to study ozone with high time resolution at different altitudes in subpolar regions, a Millimeter Wave Radiometer (MWR) was installed at the Observatorio Atmosférico de la Patagonia Austral (OAPA), Río Gallegos, Argentina, (51.6° S; 69.3° W) by 2011. This instrument provides ozone profiles with time resolution of ~ 1 hour which enables studies of short term ozone mixing ratio variability from 25 to 70 km in altitude. This work presents the MWR ozone observations between October 2014 and 2015 focusing on an atypical event of polar vortex and ozone hole influence over Río Gallegos detected from the MWR measurements at 27 and 37 km during November of 2014. The advected potential vorticity (APV) calculated from the high-resolution advection model MIMOSA (Modélisation Isentrope du transport Méso-échelle de l'Ozone Stratosphérique par Advection) was also analysed at 675 and 950 K to understand and explain the dynamic at both altitudes and correlate the ozone rapid variation during the event with the passage of the polar vortex. In addition, the MWR dataset were compared for first time with measurements obtained from Microwave Limb Sounder (MLS) at individual altitude levels (27 km, 37 km and 65 km) and with the Differential Absorption Lidar (DIAL) installed in OAPA to analyse the correspondence between the MWR and independent instruments. The MWR-MLS comparison presents reasonable correlation with a mean bias error of +5 %, −11 % and −7 % at 27 km, 37 km and 65 km, respectively. The MWR-DIAL comparison at 27 km presents also good agreement with a mean bias error of −1 %.

Description: Understanding the role of ocean currents in the recruitment of commercially and ecologically important fish is an important step toward developing sustainable resource management guidelines. To this end, we attempt to elucidate the role of surface ocean transport in supplying recruits of European sardine (Sardinus pilchardus) to the Gulf of Manfredonia, a known recruitment area in the Adriatic Sea. Sardine early life history stages (ELHS) were collected during two cruises to provide observational estimates of age-size relationship and of their passive pelagic larval duration (PPLD). We combine these PPLDs with observations of surface ocean currents to test two hypotheses: (1) ELHS are transported from remote spawning areas (SAs) by ocean currents to the Gulf of Manfredonia; (2) sardines spawn locally and ELHS are retained by eddies. A historical surface drifter database is used to test hypotheses 1. Hypothesis 2 is tested by estimating residence times of surface drifters and virtual particles trajectories that were computed from high resolution observations of surface currents measured by a High Frequency (HF) radar network. Transport to the Gulf of Manfredonia from remote SAs seems more likely than local spawning and retention given a mismatch between observed PPLDs of 30–50 days and relatively short (