Evaluation of the anti-fouling efficacy of bacillus licheniformis extracts under environmental and natural conditions

There is an increasing interest in developing innovative coatings and testing natural products with anti-fouling activity to substitute current highly toxic biocides that have a harmful impact on marine organisms. Bacillus licheniformis species have shown different anti-biofilm and anti-fouling activities in vitro, but so far, its efficacy in field trials has not been tested. For this purpose, the capacity of different extracts of B. licheniformis NCTC 10341T to prevent micro and macro-fouling was first tested in vitro. The methanol cell extract (MCE) inhibited bacterial biofilm formation without significantly affecting planktonic growth and displayed a significant efficacy to prevent larval settlement of the macro-fouler Bugula neritina in vitro without inducing lethality. Additionally, the MCE presented low toxicity against the non-target species Artemia salina. The B. licheniformis MCE was then incorporated in a self-polishing paint at 2 and 5% w/w and tested in a static immersion experiment in the Gulf of Aqaba (northern Red Sea) for 180 days. Fouling coverage decreased by 30% in the 5% MCE-treated panels in comparison with the control panels. Differences in the anti-biofilm activity of the extracts depending on the culture medium highlight the importance of the strict control of culture conditions for the production of biomass with stable bioactive activity. The results indicate the potential of B. licheniformis NCTC 10341T crude extracts for environmentally friendly anti-fouling applications, although a deeper characterization of the bioactive compounds present in the B. licheniformis MCE and its mode of action is required to allow strict control of the activity of the extracts to achieve large-scale industrial productionThis work was supported by the European Union under Grant FP7-OCEAN-2013 612717 (Low-toxic cost-efficient environment-friendly anti-fouling materials). AM was supported by a predoctoral fellowship from the Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia (ED481A-2015/311). CM was supported by a post-doctoral fellowship from Xunta de Galicia (IN606B-2019/010)S

Implications of epigallocatechin-3-gallate in cultured human Sertoli cells glycolytic and oxidative profile

Sertoli cells are crucial for the success of spermatogenesis, which is the biological process that ensures male fertility. These cells present high metabolic rates, being often subjected to high oxidative stress levels that, if uncontrolled, may compromise male fertility. Since the most abundant tea catechin, epigallocatechin-3-gallate (EGCG), has demonstrated a potent preventive activity against oxidative stress, we have evaluated its effect at concentrations of 5 and 50μM, on the metabolism, mitochondrial functionality and oxidative profile of human Sertoli cells (hSCs). While, the highest concentration of EGCG (50μM) increased glucose and pyruvate consumption, it decreased the conversion of pyruvate to alanine to sustain a regular lactate production. However, despite maintaining Krebs cycle functionality, EGCG (50μM) decreased mitochondrial membrane potential of hSCs, which could compromise the normal rates of ATP production. Interestingly, oxidative damages to proteins and lipids decreased in this experimental group, which may be valuable for the nutritional support of spermatogenesis.info:eu-repo/semantics/publishedVersio

Monitoring Arctic Sea Ice During One Year: Linearly Polarized GNSSReflectometry at the MOSAiC Campaign

Ponencia expuesta online en el 41st annual IGARSS (2021) celebrado en Bruselas del 12-16 de juli

Measuring ocean surface velocities with the KuROS and KaRADOC airborne near-nadir Doppler radars: a multi-scale analysis in preparation of the SKIM mission, Submitted to Ocean SCience, July 2019

Surface currents are poorly known over most of the oceans. Satellite-borne Doppler Waves and Current Scatterom-eters (DWCS) can be used to fill this observation gap. The Sea surface KInematics Multiscale (SKIM) proposal, is the first satellite concept built on a DWCS design at near-nadir angles, and now one of the two candidates to become the 9th mission of the European Space Agency Earth Explorer program. As part of the detailed design and feasibility studies (phase A) funded by ESA, airborne measurements were carried out with both a Ku-Band and a Ka-Band Doppler radars looking at the sea surface at 5 near nadir-incidence in a real-aperture mode, i.e. in a geometry and mode similar to that of SKIM. The airborne radar KuROS was deployed to provide simultaneous measurements of the radar backscatter and Doppler velocity, in a side-looking configuration , with an horizontal resolution of about 5 to 10 m along the line of sight and integrated in the perpendicular direction over the real-aperture 3-dB footprint diameter (about 580 m). The KaRADOC system has a much narrower beam, with a circular footprint only 45 m in diameter. 10 The experiment took place in November 2018 off the French Atlantic coast, with sea states representative of the open ocean and a well known tide-dominated current regime. The data set is analyzed to explore the contribution of non-geophysical velocities to the measurement and how the geophysical part of the measured velocity combines wave-resolved and wave-averaged scales. We find that the measured Doppler velocity contains a characteristic wave phase speed, called here C 0 that is analogous to the Bragg phase speed of coastal High Frequency radars that use a grazing measurement geometry, with little 15 variations ∆ C associated to changes in sea state. The Ka-band measurements at an incidence of 12 • are 10% lower than the theoretical estimate C 0 2.4 m/s for typical oceanic conditions defined by a wind speed of 7 m/s and a significant wave height of 2 m. For Ku-band the measured data is 1 https://doi. 30% lower than the theoretical estimate 2.8 m/s. ∆ C is of the order of 0.2 m/s for a 1 m change in wave height, and cannot be confused with a 1 m/s change in tidal current. The actual measurement of the current velocity from an aircraft at 4 to 18 • incidence angle is, however, made difficult by uncertainties on the measurement geometry, which are much reduced in satellite measurements

Ocean Surface Current Airborne Radar (OSCAR): a new instrument to measure ocean surface dynamics at the sub-mesoscale

Oceans form Space V Symposium, 24-28 october 2022, Venice, Italy.-- 2 pages, 3 figuresThe ocean interacts with the atmosphere, land and ice on multiple spatial scales including fine submesoscales that are often observed in high resolution optical images. Little is known about their dynamics however. SeaSTAR is an innovative satellite mission concept that proposes to address this gap by mapping ocean current and wind vectors at 1 km resolution. In this paper, we present the OSCAR instrument - an airborne demonstrator of the SeaSTAR concept - and the first results from a scientific campaign over the Iroise Sea in May 2022. The capabilities of OSCAR are demonstrated against ground truth data with very promising first results. These results open the door to using OSCAR as a scientific tool to provide unique 2D synoptic views of ocean and atmosphere dynamics at km-scalesThis work was supported by ESA/ESTEC Contract Number 4000116410/16/NL/BJ for the OSCAR development and ESA/ESTEC contract number 400017623/22/NL/IA for the campaign over Iroise SeaPeer reviewe

In Situ Reference Datasets From the TropiSAR and AfriSAR Campaigns in Support of Upcoming Spaceborne Biomass Missions

Tropical forests are a key component of the global carbon cycle. Yet, there are still high uncertainties in forest carbon stock and flux estimates, notably because of their spatial and temporal variability across the tropics. Several upcoming spaceborne missions have been designed to address this gap. High-quality ground data are essential for accurate calibration/validation so that spaceborne biomass missions can reach their full potential in reducing uncertainties regarding forest carbon stocks and fluxes. The BIOMASS mission, a P-band SAR satellite from the European Space Agency (ESA), aims at improving carbon stock mapping and reducing uncertainty in the carbon fluxes from deforestation, forest degradation, and regrowth. In situ activities in support of the BIOMASS mission were carried out in French Guiana and Gabon during the TropiSAR and AfriSAR campaigns. During these campaigns, airborne P-band SAR, forest inventory, and lidar data were collected over six study sites. This paper describes the methods used for forest inventory and lidar data collection and analysis, and presents resulting plot estimates and aboveground biomass maps. These reference datasets along with intermediate products (e.g., canopy height models) can be accessed through ESA's Forest Observation System and the Dryad data repository and will be useful for BIOMASS but also to other spaceborne biomass missions such as GEDI, NISAR, and Tandem-L for calibration/validation purposes. During data quality control and analysis, prospects for reducing uncertainties have been identified, and this paper finishes with a series of recommendations for future tropical forest field campaigns to better serve the remote sensing community.Additional co-authors: Gaelle Jaouen, David Kenfack, Lisa Korte, Simon L Lewis, Yadvinder Malhi, Herve R Memiaghe, John R Poulsen, Maxime Rejou-Mechain, Ludovic Villard, Gregoire Vincent, and Sassan Saatch

A North Atlantic deep-water eddy in the Agulhas Current system

One hundred and twelve stations of CTDO2 and LADCP were collected in the Agulhas Current system as part of the Agulhas Undercurrent experiment (AUCE) in March 2003. Along an offshore section, at approximately 35.6°S and 27.3°E to the northwest of the tip of the Agulhas Plateau, an unusual feature was revealed between 2200 and 3500 m depth, imbedded in the northward moving NADW layer. An anomalously high salinity of 34.83, 0.03 saltier than the surrounding water, was observed. Maximums in the potential temperature and oxygen were also found, with isotherms dropping by about 250 m over 50 km and a doming of the oxygen layers. From the convex lens structure of the neutral surfaces, we conclude that we sampled an anticyclonic eddy of NADW. Since the LADCP data reveal deep velocities up to 20 cm s −1, yet no anticyclonic circulation, whereas the geostrophic velocity referenced to the bottom shows a weak anticyclonic circulation, we inferred that we sampled the outer edge of the eddy and not its core. From an analysis of the water properties within the eddy and a comparison with known properties in the SE Atlantic Ocean and SW Indian Ocean, we conclude that the eddy was formed in the Agulhas Retroflection region. We speculate that the eddy was the result of an instability in the NADW slope current, which flows from the SE Atlantic around the Agulhas Bank. A deeply penetrating Agulhas Ring spun up the deep waters, pinching off an eddy, which later detached from the slope current and was carried southward. Once offshore, it coupled with the surface Agulhas Return Current, whose meandering path advected the eddy northeastward and ejected it over the Agulhas Plateau

Structure and downstream evolution of the Agulhas Current system during a quasi‐synoptic survey in February–March 2003

The Agulhas Undercurrent Experiment took place in February–March 2003 off the east coast of South Africa and consisted of four sections of hydrographic and velocity data across the Agulhas Current between 30 and 36°S and connecting offshore sections that formed three closed boxes. An inverse model was applied to the quasi‐synoptic data, and results show that the net mass transport at the historical 32°S section had a considerably higher transport of 100 ± 9 Sv than earlier estimates. This high transport falls within the peak‐to‐peak variability obtained previously from a current meter time series. Several mesoscale cyclonic eddies extending down to intermediate depths were sampled during the survey; in particular, a strong, locally formed shear edge eddy was found inshore of the Agulhas Current at 36°S. Offshore eddies were found to drive considerable onshore‐offshore fluxes, resulting in highly variable Agulhas transports from one section to another. After attempting to account for and remove the influence of these eddies on the Agulhas transport, the downstream growth of the Agulhas Current is found to be consistent with the Sverdrup transport variation, within errors. To account for the total magnitude of the Agulhas transport, fluxes from both the Indonesian Throughflow and Indian Ocean overturning must also be taken into account. There is no clear evidence from this study for a significant contribution of inertial recirculation to the Agulhas within this latitude range