Composition Chimique Et Influence De Différents Tweens Sur Le Pouvoir Antimicrobien Des Huiles Essentielles De Ocimum Gratissimum, Ocimum Basilicum, Laurus Nobilis Et Melaleuca Quinquenervia

This study aimed firstly to determine the chemical composition, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of essential oils extracted from Ocimum gratissimum, Ocimum basilicum, Laurus nobilis and Melaleuca quinquenervia collected from Benin (West Africa) on five oral microorganisms (Micrococcus luteus ATCC 10240, Staphylococcus aureus ATCC 29213, Proteus mirabilis ATCC 24974, Pseudomonas aeruginosa ATCC 27853 and Candida albicans IP 4872), and secondly to assess the influence of different tweens on antimicrobial potential of four oils against previous microorganisms. Using Clevenger apparatus, oil extraction was performed by steam distillation and the chemical compositions was determined by chromatography. The antimicrobial activity of different oils was evaluated according to microdilution method using ELISA microplates. From this study, Tween 60 proved best to others tweens (20, 40 and 80) by ensuring proper dispersion and distribution of oils. With tween 60, O. brasilicum essential oil proved the most effective of the four oils with the lowest MIC (0.078 mg/ml) and CMB (0.078 mg/ml) and is effective on all oral germs tested. Chemical screening of these species revealed the presence of several compounds among which thymol (30.62%), para-cymene (25.25%) and gamma-terpinolene (24.24%) (O. gratissimum); methyl-chavicol (85.92%) (O. basilicum); eugenol (42.50%), myrcene (28.09%) (L. nobilis) and beta-ocimene (29.62%), alphapinene (12.11%) and viridiflorol (11.85%) (M. quinquenervia)

Mixing and Circulation in the Tropical Atlantic Cruise No. M98

July 01 – July 28, 2013 Fortaleza (Brazil) – Walvis Bay (Namibia

A multi-decade record of high quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) “living data” publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT_V3_GRID

Spatial variability in autumnal equatorial upwelling intensity within the Gulf of Guinea as inferred from in situ measurements

In attempt to study the spatial differences in autumnal equatorial upwelling intensity relative to bio-productivity in the eastern equatorial Atlantic, oceanographic in situ data along regions 10°W, 0°E, 2.5°E and 6°E, collected in the Gulf of Guinea during autumn cruise carried out in September 2007 were analyzed. The surface mean values for temperature along 10°W, 0°E, 2.5°E and 6°E are 25.02, 26.15, 26.88 and 25.60°C, respectively. There was eastward weakening of the equatorial undercurrent from 10°W until its complete disappearance at 6°E. The highest concentration of nitrate recorded at the surface at 10°W was attributed to the shoaling pycnocline observed at this region. The surface mean values for nitrate along 10°W, 0°E, 2.5°E and 6°E are 0.37, 0.09, 0.04 and 0.04 μmol.kg-1, respectively. In response to the shoaling pycnocline at 10°W, corresponding to the highest concentration of chlorophyll fluorescence was recorded at this region. The surface mean values for chlorophyll fluorescence along 10°W, 0°E, 2.5°E and 6°E are 0.34, 0.05, 0.07 and 0.08 mg/m3, respectively. Contributions to equatorial upwelling by the equatorial undercurrent were the strongest and mostly expressed along 10°W. Profiles for apparent oxygen utilization and chlorophyll fluorescence gave indications that biological response to surface enrichments within the equatorial bands was highest at region 10°W. Vertical sections for studied parameters were unsuggestive of westward advection from 6°E to 10°W within the equatorial band, and this signifies the important role of vertical processes in equatorial enrichment at 10°W during boreal autumn

Error proxies in video-based depth inversion : temporal celerity estimation

The accuracy of bathymetric measurements is crucial, especially to understand coastal processes. Video-based depth inversion methods have been widely developed in recent years, but they remain noisy, with typical errors due to the breakpoint optical and non-linear effects. Among the spectral and temporal approaches to video depth inversion, only the spectral approach applies an error criterion to identify erroneous data. Here, two error proxies are assimilated for the first time in the temporal approach, using a Kalman filter applied to 3.5 years (February 2013 to September 2016) of video images. Differences between filtered and unfiltered bathymetries were observed to be correlated with the proxies considered. A validation with field data on a 10-day experiment is performed between the original bathymetries and the filtered bathymetries. The results indicate that the mean square error can be reduced by at least 30%. Both proxies show good ability to correct depth estimates. Although the results are promising, validation of these approximations must be performed under various hydrodynamic and atmospheric conditions

Beach adaptation to intraseasonal sea level changes

International audienceCoastal areas such as beaches with steep upper slope and flat low-tide terrace, are expected to be increasingly affected by sea level changes. Related impacts due to the paramount rise in sea level have been intensively investigated, but there is still little evidence of the impact of shorter timescales variations on the coast, particularly those induced by trapped coastal waves. Using the latest advances in video bathymetric estimation, daily observations over 3.5 years (February 2013 to June 2016) on Grand Popo Beach (West Africa) reveal that intraseasonal sea level variations impact the beach profile. The intraseasonal sea level variations are dominated by the propagation of wind forced coastal trapped waves with periods ranging 15-95 days. It is shown that the beach goes through a transient state with a deformation of the profile: an intraseasonal sea level rise leads to a 2 m erosion of the upper beach and a widening of the flat terrace at the lower beach. Although the underlying mechanism must be tested through beach profile modelling, this study highlights the active adaptation of the beach profile to variations in sea level

Shoreline and beach cusps dynamics at the low tide terraced Grand Popo Beach, Benin (West Africa) : a statistical approach

This paper presents the description of a 2-dimensional shoreline and 3-dimensional shoreline behaviour around a 'storm free' microtidal beach from a 3-year video observation using empirical orthogonal function (EOF) analysis. The EOF method is applied successfully to delineate 2D and 3D developments that show the beach evolution influenced by the action of waves and tides. The EOF model results are in agreement with measurements that reflect the morphological concepts for the 2D and 3D cases: the first temporal EOF mode which accounts for an overwhelming 80% of shoreline variation reflects the alongshore-averaged cross-shore migration (2D) largely influenced by waves while the higher eigenfunctions with 20% shoreline variation reflect beach deformation/irregularities (3D). Shoreline location is correlated to cross-shore energy flow from waves, while 3D is associated to the longshore energy flow. The influence of wave height increases cross-shore uniform migration and beach seasonality. The results show that with EOF method, beach cusps are clearly identified for 3D developments to be evaluated. Beach cusps are well observed at low tides on video images. Tide and cusps increase the importance of short term events and deformation; at the lowest high tide mark, beach cusps were observed on higher spatial functions of EOF. This indicates that a study of these morphological features as a coupled system, promotes their contribution in predicting 2D and 3D shoreline changes

International conference ICAWA 2016 : extended book of abstract : the AWA project : ecosystem approach to the management of fisheries and the marine environment in West African waters

Several studies have been carried out in the Gulf of Guinea to understand the complex dynamics that control the evolution of tropical coastal environments. The results, based on altimetric and re-analyzes data, revealed the variability of hydrodynamic and morphological processes. These results were validated in the short term with field measurement campaigns. In this paper, we propose a validation of the seasonal and inter-seasonal variability from data collected with a video system installed at Grand Popo, Benin since February 2013 - September 2016. Its potential is assessing event and seasonal coastline behaviour have been demonstrated in a previous study. The video system was used to track the evolution of hydrodynamic parameters and beach's state at high frequency and continuously. A comparison of video estimates is carried out with ERAInterim re-analysis data. The results show a strong correlation between seasonal cycles of hydrodynamic parameters and shoreline's position. However, the qualitative variation of the beach (beach slope) is still strongly linked to other parameters (tide and cross-shore transport processes). During the study period, the Grand Popo beach experienced a gradual decline of its shoreline, reflecting the presence of a strong trend or an inter-seasonal (inter-annual) cycle