Sinkhole susceptibility evaluation in Apulia, southern Italy

In some regions in Italy sinkholes are frequent and pose a serious threat to structures and infrastructures. Apulia region is largely affected by sinkholes of both natural and anthropogenic origin, due to the karst nature of large portions of the regional territory and to high diffusion of artificial cavities. For this reasons, susceptibility, hazard and risk posed by sinkholes must be estimated in order to gain more insights into their spatial and temporal distribution, and to apply appropriate risk management and to take proper mitigation strategies. In order to estimate the susceptibility to sinkholes in Apulia, the ensemble statistical modelling proposed by Rossi et al. (2010) and later refined by Rossi & Reichenbach (2016) is used. This allows assessing susceptibility using differentiated statistical approaches, quantifying accurately the modelling performances, and evaluating the associated uncertainty. In order to obtain accurate and reliable results thematic layers related to the sinkholes occurrence were carefully evauated and selected. This contribution shows the preliminary results of the analyses to evaluate the susceptibility to natural sinkholes, which used as training dependent (i.e. grouping) set, data extracted from the regional inventory of natural caves, edited by the Apulian Speleological Federation (www.catasto.fspuglia.it), and as validation set the natural sinkholes occurred in Apulia, collected in the chronological catalogue of sinkholes in Italy (Parise & Vennari, 2013, 2017). Appropriate thematic layers, were selected heuristically on the base of the knowledge on the triggering mechanisms and the nature of the phenomenon gained previously in the study area. Resulting regional-scale susceptibility map will be appropriately validated. The methodological procedure will be applied to the evaluation of susceptibility for anthropogenic sinkholes as well

Karst geomorphology of the “Canale di Pirro” polje, Apulia (Southern Italy).

In karst environment, a geomorphological map is a powerful instrument, which play a crucial role in understanding earth surface processes and landscape evolution. Furthermore, it could be very useful for speleological perspectives, natural resources exploitation and geo-hazards management (flood, sinkhole, subsidence, etc.), providing useful information that enhance the knowledge of the territory. In this work, we present a geomorphological map of the polje of “Canale di Pirro”, sited in the central part of Apulia Region, in Southern Italy, among the most interesting karst lands in the Mediterranean area. The map covers150km2withanelevationrangeof100-450ma.s.l.Thisareaisoneofthemostremarkablekarstlandforms in the region, characterized underground by a very interesting system of caves, that reaches the water table at a depth of -264 meters. The karst system, known as “Inghiottitoio di Masseria Rotolo”, following scuba-diving exploration below the watertable, has become with a depth of 324m, the deepest known cave in Apulia. The polje is bounded on both sides by tectonically-controlled ridges, showing an overall length of some 12 km. In ancient maps, dating back to the 16th century, the area is represented as crossed by a long river, called Cana. The map obtained derives from the integration of interpretation of aerial photographs, analysis of a digital elevation model and field surveys in order to obtain a correct distribution of landforms and fluvial processes, such as different varieties of karst depressions, conical hills, erosional gullies, alluvial fans and tectonic structures. It provides relevant information about the surface drainage processes, and for understanding, among other things, the groundwater circulation and the related recharge processes. This geomorphological map is part of a wider project, that combined geological, hydrogeological research and chemical analyses of the groundwater. It provides support to the ongoing studies of this part of Apulia region aimedto betterunderstand thegeological processes that originatedthe polje and its later evolution, and the related underground cave system. Further, it might also suggest possible improvements in land management and in the future choice of useful tools for the control of the quality and quantity of karst groundwater

Regulation of ligand binding to glycoprotein IIb-IIIa (integrin α IIb β 3 ) in isolated platelet membranes

The major platelet integrin, glycoprotein IIb-IIIa, binds soluble fibrinogen only after platelet activation. To investigate the mechanism by which platelets convert glycoprotein IIb-IIIa into a functional fibrinogen receptor, we characterized the opening and closing of fibrinogen-binding sites in isolated platelet membranes and compared the regulatory properties of membrane-bound glycoprotein IIb-IIIa with those of the detergent-solubilized receptor. Basal fibrinogen binding to the membranes possessed many of the properties of fibrinogen binding to activated platelets; however, less than 10% of glycoprotein IIb-IIIa in the membranes was capable of binding fibrinogen. Preincubating the membranes with either an activating glycoprotein IIb-IIIa antibody or alpha-chymotrypsin increased fibrinogen binding. In contrast, agents that require intracellular mediators, such as platelet agonists, guanine-nucleotide-binding-protein activators and purified protein kinase C, did not stimulate fibrinogen binding to the membranes, suggesting that cytosolic factor(s) may be required for activation of the receptor in platelets. Occupancy of glycoprotein IIb-IIIa in the membranes with RGD (Arg-Gly-Asp)-containing peptides reversibly exposed neoantigenic epitopes and fibrinogen-binding sites in the receptor. These conformational changes required membrane fixation to be maintained following peptide removal. Similar results were obtained with purified glycoprotein IIb-IIIa incorporated into phospholipid vesicles, indicating that the resting state of the receptor is favoured in these environments. In contrast, when the conformation of detergent-solubilized glycoprotein IIb-IIIa was altered by exposure to RGD-containing peptides, the receptor remained active even after incorporation into phospholipid vesicles. These results demonstrate that platelet membranes are a useful model in which to study the regulation of glycoprotein IIb-IIIa and suggest that the environment surrounding the receptor may have a profound influence on this process

The Interaction between AID and CIB1 Is Nonessential for Antibody Gene Diversification by Gene Conversion or Class Switch Recombination

Activation-induced deaminase (AID) initiates somatic hypermutation, gene conversion and class switch recombination by deaminating variable and switch region DNA cytidines to uridines. AID is predominantly cytoplasmic and must enter the nuclear compartment to initiate these distinct antibody gene diversification reactions. Nuclear AID is relatively short-lived, as it is efficiently exported by a CRM1-dependent mechanism and it is susceptible to proteasome-dependent degradation. To help shed light on mechanisms of post-translational regulation, a yeast-based screen was performed to identify AID-interacting proteins. The calcium and integrin binding protein CIB1 was identified by sequencing and the interaction was confirmed by immunoprecipitation experiments. The AID/CIB1 resisted DNase and RNase treatment, and it is therefore unlikely to be mediated by nucleic acid. The requirement for CIB1 in AID-mediated antibody gene diversification reactions was assessed in CIB1-deficient DT40 cells and in knockout mice, but immunoglobulin gene conversion and class switch recombination appeared normal. The DT40 system was also used to show that CIB1 over-expression has no effect on gene conversion and that AID-EGFP subcellular localization is normal. These combined data demonstrate that CIB1 is not required for AID to mediate antibody gene diversification processes. It remains possible that CIB1 has an alternative, a redundant or a subtle non-limiting regulatory role in AID biology

Evidence for novel binding sites on the platelet glycoprotein IIb and IIIa subunits and immobilized fibrinogen

The present study was designed to examine the interaction of the purified platelet glycoprotein IIb-IIIa complex (GP IIb-IIIa or integrin alpha IIb beta 3) and the individual subunits of the complex with immobilized fibrinogen. Although 125I-GP IIb-IIIa binding to fibrinogen immobilized on Sepharose was specific, this interaction exhibited properties distinct from those of reversible fibrinogen binding to platelets: 125I-GP IIb-IIIa binding appeared irreversible, but non-covalent, Ca(2+)-independent, and was inhibited only weakly, or not at all, by the anti-(GP IIb-IIIa) monoclonal antibodies 10E5 and 7E3 and synthetic peptides from known platelet-binding domains of fibrinogen. Reversibly dissociated GP IIb or GP IIIa subunits inhibited 125I-GP IIb-IIIa binding to immobilized fibrinogen and bound directly to the fibrinogen. However, these subunits did not bind to peptides derived from known platelet-binding domains within the fibrinogen alpha- and gamma-chains, although the GP IIb-IIIa complex did. These results show that the complexed form of full-length GP IIb and GP IIIa is required for binding to these synthetic peptides, but not necessarily for binding to immobilized fibrinogen. Thus GP IIb-IIIa can bind to immobilized fibrinogen by a distinct mechanism that appears to involve novel binding sites on each subunit of the GP IIb-IIIa complex and on fibrinogen

Evidence for novel binding sites on the platelet glycoprotein IIb and IIIa subunits and immobilized fibrinogen

The present study was designed to examine the interaction of the purified platelet glycoprotein IIb-IIIa complex (GP IIb-IIIa or integrin alpha IIb beta 3) and the individual subunits of the complex with immobilized fibrinogen. Although 125I-GP IIb-IIIa binding to fibrinogen immobilized on Sepharose was specific, this interaction exhibited properties distinct from those of reversible fibrinogen binding to platelets: 125I-GP IIb-IIIa binding appeared irreversible, but non-covalent, Ca(2+)-independent, and was inhibited only weakly, or not at all, by the anti-(GP IIb-IIIa) monoclonal antibodies 10E5 and 7E3 and synthetic peptides from known platelet-binding domains of fibrinogen. Reversibly dissociated GP IIb or GP IIIa subunits inhibited 125I-GP IIb-IIIa binding to immobilized fibrinogen and bound directly to the fibrinogen. However, these subunits did not bind to peptides derived from known platelet-binding domains within the fibrinogen alpha- and gamma-chains, although the GP IIb-IIIa complex did. These results show that the complexed form of full-length GP IIb and GP IIIa is required for binding to these synthetic peptides, but not necessarily for binding to immobilized fibrinogen. Thus GP IIb-IIIa can bind to immobilized fibrinogen by a distinct mechanism that appears to involve novel binding sites on each subunit of the GP IIb-IIIa complex and on fibrinogen

Ultraviolet Spectrum of the Crab Nebula

Data from 65 hours of observation of the Crab Nebula with the International Ultraviolet Explorer are reported, together with new ground-based spectrophotometry. We have measured the important C IV λ1549, He II λ1640, and C III] λ1908 emission line intensities and placed upper limits on other ultraviolet features for the brightest filamentary region in the nebula. We have also measured some ultraviolet continuum surface brightnesses at two places in the Crab. The emission lines imply an average ionic abundance ratio n(C^+2)/n(O^+2 ) in the range from 0.4 to 1.5 in the observed gaseous condensations. The elemental abundance ratio of carbon to oxygen is probably in the same range. This range may be narrowed through the use of ionization calculations, but even our simple analysis shows that there is no perceptible excess of carbon, due to presupernova nucleosynthesis, in the observed region. The large helium abundance, small carbon and oxygen abundances, and presence of a neutron star in the Crab Nebula suggest that the presupernova star had a mass close to 8 M0 when it was on the main sequence

Deuterated water in the solar-type protostars NGC 1333 IRAS 4A and IRAS 4B

Aims. The aim of this paper is to study deuterated water in the solar-type protostars NGC1333 IRAS4A and IRAS4B, to compare their HDO abundance distribution with other star-forming regions, and to constrain their HDO/H2O ratios. Methods. Using the Herschel/HIFI instrument as well as ground-based telescopes, we observed several HDO lines covering a large excitation range (Eup/k=22-168 K) towards these protostars and an outflow position. Non-LTE radiative transfer codes were then used to determine the HDO abundance profiles in these sources. Results. The HDO fundamental line profiles show a very broad component, tracing the molecular outflows, in addition to a narrower emission component and a narrow absorbing component. In the protostellar envelope of NGC1333 IRAS4A, the HDO inner (T>100 K) and outer (T<100 K) abundances with respect to H2 are estimated at 7.5x10^{-9} and 1.2x10^{-11}, respectively, whereas, in NGC1333 IRAS4B, they are 1.0x10^{-8} and 1.2x10^{-10}, respectively. Similarly to the low-mass protostar IRAS16293-2422, an absorbing outer layer with an enhanced abundance of deuterated water is required to reproduce the absorbing components seen in the fundamental lines at 465 and 894 GHz in both sources. This water-rich layer is probably extended enough to encompass the two sources as well as parts of the outflows. In the outflows emanating from NGC1333 IRAS4A, the HDO column density is estimated at about (2-4)x10^{13} cm^{-2}, leading to an abundance of about (0.7-1.9)x10^{-9}. An HDO/H2O ratio between 7x10^{-4} and 9x10^{-2} is derived in the outflows. In the warm inner regions of these two sources, we estimate the HDO/H2O ratios at about 1x10^{-4}-4x10^{-3}. This ratio seems higher (a few %) in the cold envelope of IRAS4A, whose possible origin is discussed in relation to formation processes of HDO and H2O.Comment: 16 pages, 13 figure

Murge and Pre-murge in southern Italy: the last piece of Adria, the (almost) lost continent, attempting to became an aUGGp candidate (MurGEOpark)

In 2019, the executive of the Alta Murgia National Park (southeastern Italy) decided to propose its territory as possible inclusion in the network of the UNESCO Global Geoparks. Since then, in cooperation with the Department of Earth and Environmental Sciences (Aldo Moro University of Bari) and SIGEA, it is working to candidate the area as an aUGGp (called “MurGEOpark”). The MurGEOpark comprises the Alta Murgia area, where a Cretaceous sector of the Apulia Carbonate Platform crops out, and the adjacent Pre-Murge area, where the southwestward lateral continuation of the same platform, being flexed toward the southern Apennines mountain chain, is thinly covered by Plio-Quaternary foredeep deposits. The worldwide geological uniqueness is that the area is the only in situ remnant of the AdriaPlate, the old continent almost entirely squeezed between Africa and Europe. In such a contest, AltaMurgia is a virtually undeformed sector of Adria (the Apulia Foreland), while other territories of theplate are, and/or were, involved in the subduction/collision processes. In the MurGEOpark, the crustof Adria is still rooted to its mantle, and the Cretaceous evolution of the continent is spectacularlyrecorded in Alta Murgia thanks to the limestone succession of one of the largest peri-Tethyancarbonate platform (the Apulia Carbonate Platform). The MurGEOpark comprises also the Pre-Murge area, which represents the outer south-Apennines foredeep, whose Plio-Quaternaryevolution is spectacularly exposed thanks to an “anomalous” regional middle-late Quaternary uplift.The international value of the proposal is enriched by the presence of several geological singularities such as two paleontological jewels of very different age: a Neanderthal skeletonpreserved in speleothems within a karst cave, and one of the largest surfaces in the world withupper Cretaceous dinosaur tracks (about 25.000 footprints). Moreover, the close relationships between man and geology are spectacularly documented in the MurGEOpark: among the others, the use and conservation of water in a karst area, the prehistoric and ancestral choices ofurbanization, karst caves traditionally used as religious sites, etc. All these examples demonstratehow the MurGEOpark could offer a good opportunity to spread the geological culture to a wide and diverse audienc

Forecasting global atmospheric CO_2

A new global atmospheric carbon dioxide (CO_2) real-time forecast is now available as part of the pre-operational Monitoring of Atmospheric Composition and Climate – Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO_2 forecasting system is that the land surface, including vegetation CO_2 fluxes, is modelled online within the IFS. Other CO_2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO_2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO_2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO_2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO_2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO_2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO_2 fluxes also lead to accumulating errors in the CO_2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO_2 fluxes compared to total optimized fluxes and the atmospheric CO_2 compared to observations. The largest biases in the atmospheric CO_2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO_2 analyses based on the assimilation of CO_2 products retrieved from satellite measurements and CO_2 in situ observations, as they become available in near-real time. In this way, the accumulation of errors in the atmospheric CO_2 forecast will be reduced. Improvements in the CO_2 forecast are also expected with the continuous developments in the operational IFS