The role of ascorbate in antioxidant protection of biomembranes: Interaction with vitamin E and coenzyme Q

One of the vital roles of ascorbic acid (vitamin C) is to act as an antioxidant to protect cellular components from free radical damage. Ascorbic acid has been shown to scavenge free radicals directly in the aqueous phases of cells and the circulatory system. Ascorbic acid has also been proven to protect membrane and other hydrophobic compartments from such damage by regenerating the antioxidant form of vitamin E. In addition, reduced coenzyme Q, also a resident of hydrophobic compartments, interacts with vitamin E to regenerate its antioxidant form. The mechanism of vitamin C antioxidant function, the myriad of pathologies resulting from its clinical deficiency, and the many health benefits it provides, are reviewed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44796/1/10863_2004_Article_BF00762775.pd

Mesoscale Sea Surface Salinity in the Algerian Basin observed through SMOS and ABACUS glider data

The Algerian Basin is a key component of the general circulation in the Western Mediterranean Sea. The presence of both fresh Atlantic water and more saline Mediterranean water gives the basin an intense inflow/outflow regime and complex circulation patterns. Energetic mesoscale structures that evolve from meanders of the Algerian Current into isolated cyclonic and anticyclonic eddies dominate the area, with marked repercussions on biological activity. In recent years, several studies have demonstrated the advantages of combined use of autonomous underwater vehicles, such as gliders, with remotely sensed products. In this framework, an important contribution could come from a new generation of enhanced sea surface salinity (SSS) products, i.e. Soil Moisture and Ocean Salinity (SMOS), Soli Mosture Active Passive (SMAP) and Aquarius. Here we present a preliminary study to assess the advantages of using the enhanced SMOS SSS products obtained through a new methodology using a combination of debiased non-Bayesian retrieval, DINEOF (Data Interpolating Empirical Orthogonal Functions) and multifractal fusion with high resolution Sea Surface Temperature (OSTIA SST) maps for improving their spatial and temporal resolution in the Western Mediterranean Sea (Olmedo et al., 2018). The Algerian Basin SSS described by the new SMOS maps have been compared with the in situ high resolution glider measurements collected in the framework of the ABACUS series observational program conducted in the Algerian Basin during fall 2014 – 2017 and spring 2017 – 2018 (Cotroneo et al., 2016; Aulicino et al., 2018). The achieved results show that i) the enhanced SMOS products well represent the salinity patterns described by in situ SSS; ii) the mesoscale structures described by SMOS in the Algerian Basin coincide with those identified by gliders and described by altimetry and MODIS images

Mesoscale Sea Surface Salinity in the Algerian Basin observed through SMOS and ABACUS glider data

The Algerian Basin is a key component of the general circulation in the Western Mediterranean Sea. The presence of both fresh Atlantic water and more saline Mediterranean water gives the basin an intense inflow/outflow regime and complex circulation patterns. Energetic mesoscale structures that evolve from meanders of the Algerian Current into isolated cyclonic and anticyclonic eddies dominate the area, with marked repercussions on biological activity. In recent years, several studies have demonstrated the advantages of combined use of autonomous underwater vehicles, such as gliders, with remotely sensed products. In this framework, an important contribution could come from a new generation of enhanced sea surface salinity (SSS) products, i.e. Soil Moisture and Ocean Salinity (SMOS), Soli Mosture Active Passive (SMAP) and Aquarius. Here we present a preliminary study to assess the advantages of using the enhanced SMOS SSS products obtained through a new methodology using a combination of debiased non-Bayesian retrieval, DINEOF (Data Interpolating Empirical Orthogonal Functions) and multifractal fusion with high resolution Sea Surface Temperature (OSTIA SST) maps for improving their spatial and temporal resolution in the Western Mediterranean Sea (Olmedo et al., 2018). The Algerian Basin SSS described by the new SMOS maps have been compared with the in situ high resolution glider measurements collected in the framework of the ABACUS series observational program conducted in the Algerian Basin during fall 2014 – 2017 and spring 2017 – 2018 (Cotroneo et al., 2016; Aulicino et al., 2018). The achieved results show that i) the enhanced SMOS products well represent the salinity patterns described by in situ SSS; ii) the mesoscale structures described by SMOS in the Algerian Basin coincide with those identified by gliders and described by altimetry and MODIS images

Sea surface salinity and temperature in the Southern Atlantic Ocean from South African icebreakers, 2010-2017

We present here sea surface salinity (SSS) and temperature (SST) data collected on board the S.A. Agulhas-I and S.A. Agulhas-II research vessels, in the framework of the South African National Antarctic Programme (SANAP). Onboard Sea-Bird thermosalinographs were regularly calibrated and continuously monitored in-between cruises, and no appreciable sensor drift emerged. Water samples were taken on a daily basis and later analyzed with a Portasal salinometer; some CTD measurements collected along the cruises were used to validate the data. No systematic differences appeared after a rigorous quality control on continuous data. Results show that salinity measurement error was a few hundredths of a unit on the practical salinity scale. Quality control included several steps, among which an automatic detection of unreliable values through selected threshold criteria and an attribution of quality flags based on multiple criteria, i.e., analysis of information included in the cruise reports, detection of insufficient flow and/or presence of air bubbles and ice crystals in the seawater pipe, visual inspection of individual campaigns, and ex post check of sea ice maps for confirming ice field locations. This data processing led us to discard about 36% of acquired observations, while reliable data showed an excellent agreement with several independent SSS products. Nevertheless, a sea ice flag has been included for identifying valid data which could have been affected by scattered sea ice contamination. In our opinion, this dataset, available through an unrestricted repository at https://doi.org/10.7289/V56M3545, contributes to improving the knowledge of surface water features in one of the most important regions for global climate. The dataset will be highly valuable for studies focusing on climate variability in the Atlantic sector of the Southern Ocean, especially across the Antarctic Circumpolar Current and its fronts. Furthermore, we expect that the collected SSS data will represent a valuable tool for the calibration and validation of recent satellite observations provided by SMOS and Aquarius missions