Evidence of glacial melt water input in the Western Ross Sea (Antarctica) water masses

Ice shelves are believed to control the glacial stability and the Antarctic Ice Sheet balance, thus their melting is a critical issue. One of the recognized drivers of the ice shelf melting is the intrusion of the warm Circumpolar Deep Water (CDW) onto the Antarctic continental shelves. In the Ross Sea: CDW is a primary source of heat, salt, iron (Fe) and nutrients and plays a major role on the shelf biogeochemical processes; CDW intrudes onto the shelf preferably in the western sector, where the local glaciers are potentially exposed to this warm intrusion; CDW, besides contributing directly to the Fe input, may also have an indirect, but relevant role on the Fe bulk by enhancing the ice shelves melting and iceberg calving. The CELEBeR (CDW Effects on glaciaL mElting and on Bulk of Fe in the Western Ross Sea) project aims to investigate the role of the CDW in supplying Fe to the Ross Sea biological system both directly, as one of the main Fe sources, and indirectly by inducing the Fe-rich glacial melt water inputs in the western Ross Sea. Preliminary data on evidence of glacial melt water input in selected areas are here presented

The role of tides in bottom water export from the western Ross Sea

Approximately 25% of Antarctic Bottom Water has its origin as dense water exiting the western Ross Sea, but little is known about what controls the release of dense water plumes from the Drygalski Trough. We deployed two moorings on the slope to investigate the water properties of the bottom water exiting the region at Cape Adare. Salinity of the bottom water has increased in 2018 from the previous measurements in 2008–2010, consistent with the observed salinity increase in the Ross Sea. We find High Salinity Shelf Water from the Drygalski Trough contributes to two pulses of dense water at Cape Adare. The timing and magnitude of the pulses is largely explained by an inverse relationship with the tidal velocity in the Ross Sea. We suggest that the diurnal and low frequency tides in the western Ross Sea may control the magnitude and timing of the dense water outflow

Analysis of physical and biogeochemical control mechanisms on summertime surface carbonate system variability in the western Ross Sea (Antarctica) using in situ and satellite data

In this study, carbonate system properties were measured in the western Ross Sea (Antarctica) over the 2005–2006 and 2011–2012 austral summers with the aim of analysing their sensitivity to physical and biogeochemical drivers. Daily Advanced Microwave Scanning Radiometer 2 (AMSR2) sea ice concentration maps, obtained prior to and during the samplings, were used to analyse the sea ice evolution throughout the experiment periods. Monthly means and 8-day composite chlorophyll concentration maps from the Moderate-resolution Imaging Spectroradiometer (MODIS) Aqua satellite at 4-km resolution were used to investigate inter-annual and basin scale biological variability. Chlorophyll-a concentrations in surface waters estimated by MODIS satellite data contribute to descriptions of the variability of carbonate system properties in surface waters. Mean values of carbonate system properties were comparable across both investigated years; however, the 2012 data displayed larger variability. Sea ice melting also had a pivotal role in controlling the carbonate system chemistry of the mixed layer both directly through dilution processes and indirectly by favouring the development of phytoplankton blooms. This resulted in high pH and ΩAr, and in low CT, particularly in those areas where high chlorophyll concentration was shown by satellite maps

Trophic and Microbial Patterns in the Ross Sea Area (Antarctica): Spatial Variability during the Summer Season

In open regions of the Ross Sea, the role of the microbial community in the turnover of organic matter has scarcely been investigated; indeed, very little is known on how microbial distribution and functional diversity respond to environmental conditions and hydrographic structures. During the austral summer of 2017, two pelagic areas of the Ross Sea [the Drygalski Ice Tongue and the nearby Terra Nova Bay polynya (A area), and the continental Shelf Break area near Cape Adare (C area)] were studied at selected depths [surface, Deep Chlorophyll Maximum (DCM), Circumpolar Deep Water (CDW), deep waters]. Trophic properties [nutrient concentrations, particulate (POC), dissolved organic carbon (DOC) and its optically significant fraction (CDOM) were measured, together with the main hydrological variables. Microbial community abundance [total prokaryotes, living, dead, and actively respiring fraction, high- and low nucleic acid cells (HNA and LNA), picoand nano-eukaryotes, culturable heterotrophic bacteria], composition, and metabolism (as whole community and as isolated bacteria) were also assessed. Through a multidisciplinary dataset, this study highlighted the variable response of microbial abundance, diversity, and metabolism of the microbial community to the changing local environmental conditions of the Ross Sea. Different forces, such as organic matter inputs (mostly of detrital nature) released from the Drygalski glacier in the A area, and a coastal-to-offshore gradient in the C area, coexisted within this extreme ecosystem. This resulted in a significant spatial segregation of the edaphic parameters, and of the microbial community distribution and metabolic activity patterns

Monitoring and predicting the risk of violence in residential facilities. No difference between patients with history or with no history of violence

none34noopende Girolamo, Giovanni; Buizza, Chiara; Sisti, Davide; Ferrari, Clarissa; Bulgari, Viola; Iozzino, Laura; Boero, Maria Elena; Cristiano, Giuseppe; De Francesco, Alessandra; Giobbio, Gian Marco; Maggi, Paolo; Rossi, Giuseppe; Segalini, Beatrice; Candini, Valentina; Andreose, Suor; Basso, Pasquale; Beneduce, Rossella; Bertolotti, Pietro; Braida, Vanda; Bonelli, Marina; Bongiorno, Fanny; Bussi, Riccardo; Castagno, Elisa; Dominicis, Fabio; Ghersi, Loredana; Greppo, Stefania; Sodano, Alessandro Jaretti; Leporatti, Massimo; Presti, Eleonora Lo; Milone, Valeria; Panigada, Fausto; Pasquadibisceglie, Livia; Rigamonti, Danilo; Rillosi, Lucianade Girolamo, Giovanni; Buizza, Chiara; Sisti, Davide; Ferrari, Clarissa; Bulgari, Viola; Iozzino, Laura; Boero, Maria Elena; Cristiano, Giuseppe; De Francesco, Alessandra; Giobbio, Gian Marco; Maggi, Paolo; Rossi, Giuseppe; Segalini, Beatrice; Candini, Valentina; Andreose, Suor; Basso, Pasquale; Beneduce, Rossella; Bertolotti, Pietro; Braida, Vanda; Bonelli, Marina; Bongiorno, Fanny; Bussi, Riccardo; Castagno, Elisa; Dominicis, Fabio; Ghersi, Loredana; Greppo, Stefania; Sodano, Alessandro Jaretti; Leporatti, Massimo; Presti, Eleonora Lo; Milone, Valeria; Panigada, Fausto; Pasquadibisceglie, Livia; Rigamonti, Danilo; Rillosi, Lucian

​​Observing Antarctic Bottom Water in the Southern Ocean​

Dense, cold waters formed on Antarctic continental shelves descend along the Antarctic continental margin, where they mix with other Southern Ocean waters to form Antarctic Bottom Water (AABW). AABW then spreads into the deepest parts of all major ocean basins, isolating heat and carbon from the atmosphere for centuries. Despite AABW’s key role in regulating Earth’s climate on long time scales and in recording Southern Ocean conditions, AABW remains poorly observed. This lack of observational data is mostly due to two factors. First, AABW originates on the Antarctic continental shelf and slope where in situ measurements are limited and ocean observations by satellites are hampered by persistent sea ice cover and long periods of darkness in winter. Second, north of the Antarctic continental slope, AABW is found below approximately 2 km depth, where in situ observations are also scarce and satellites cannot provide direct measurements. Here, we review progress made during the past decades in observing AABW. We describe 1) long-term monitoring obtained by moorings, by ship-based surveys, and beneath ice shelves through bore holes; 2) the recent development of autonomous observing tools in coastal Antarctic and deep ocean systems; and 3) alternative approaches including data assimilation models and satellite-derived proxies. The variety of approaches is beginning to transform our understanding of AABW, including its formation processes, temporal variability, and contribution to the lower limb of the global ocean meridional overturning circulation. In particular, these observations highlight the key role played by winds, sea ice, and the Antarctic Ice Sheet in AABW-related processes. We conclude by discussing future avenues for observing and understanding AABW, impressing the need for a sustained and coordinated observing system

Oral ondansetron versus domperidone for acute gastroenteritis in pediatric emergency departments: Multicenter double blind randomized controlled trial

The use of antiemetics for vomiting in acute gastroenteritis in children is still a matter of debate. We conducted a double-blind randomized trial to evaluate whether a single oral dose of ondansetron vs domperidone or placebo improves outcomes in children with gastroenteritis. After failure of initial oral rehydration administration, children aged 1-6 years admitted for gastroenteritis to the pediatric emergency departments of 15 hospitals in Italy were randomized to receive one oral dose of ondansetron (0.15 mg/kg) or domperidone (0.5 mg/kg) or placebo. The primary outcome was the percentage of children receiving nasogastric or intravenous rehydration. A p value of 0.014 was used to indicate statistical significance (and 98.6% CI were calculated) as a result of having carried out two interim analyses. 1,313 children were eligible for the first attempt with oral rehydration solution, which was successful for 832 (63.4%); 356 underwent randomization (the parents of 125 children did not give consent): 118 to placebo, 119 to domperidone, and 119 to ondansetron. Fourteen (11.8%) needed intravenous rehydration in the ondansetron group vs 30 (25.2%) and 34 (28.8%) in the domperidone and placebo groups, respectively. Ondansetron reduced the risk of intravenous rehydration by over 50%, both vs placebo (RR 0.41, 98.6% CI 0.20-0.83) and domperidone (RR 0.47, 98.6% CI 0.23-0.97). No differences for adverse events were seen among groups. In a context of emergency care, 6 out of 10 children aged 1-6 years with vomiting due to gastroenteritis and without severe dehydration can be managed effectively with administration of oral rehydration solution alone. In children who fail oral rehydration, a single oral dose of ondansetron reduces the need for intravenous rehydration and the percentage of children who continue to vomit, thereby facilitating the success of oral rehydration. Domperidone was not effective for the symptomatic treatment of vomiting during acute gastroenteritis