Éditeur(s) : Université des Antilles AREBio Groupe de recherche BIOSPHERES : BIOlogie, Sciences Physiques & Humaines pour les énergies Renouvelables, l
Extrait de : 1er colloque international BIOSPHERES, du 18 au 20 juin 2019. Université des Antilles
Description : The Chemical Purification, analysis and Screening core laboratories (CPAS) are located at the University of South Florida campus in Tampa. This core offers instrumentation and expertise in fractionation, purification, and various chemical analyses to support synthetic and natural products drug discovery research groups. Our main equipment are dedicated to chromatographic separation and purification (MPLC, HPLC) and mass-spectrometry for analytic detection, quantification and identification (LC-MS SQ, QqQ and QToF). The CPAS services also include Circular Dichroism spectrometry, general spectroscopic characterization (UV, FTIR), lyophilization (bench top and high capacity freeze-dryers), synthesis (microwave reactor), ADME screening (permeability and drug solubility testing), and high-throughput screening development capability (automated liquid handler and multimode plate reader). An example of three significant studies will be presented at the conference to illustrate the CPAS core facility services: 1) Identification of new bioactive compounds from mangrove endophytic fungi as potential alternatives to malaria drug resistance, 2) Myricanol isolated from Bayberry (Myrica Cerifera) and its synthetic derivatives targeting the microtubuleassociated protein tau accumulation in the Alzheimer's disease and 3) New ent-labdane diterpenes with solid tumor cell lines antiproliferative properties from the endemic plant Eupatorium obtusissmum from the island of Hispaniola. The core provides research lab training workshops in advanced technology and assistance so users can operate any instruments available in the laboratories to successfully accomplish their analyses and research projects.

Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V19063
V19063

Éditeur(s) : HAL CCSD Elsevier
Résumé : We describe, test, and explain the relative effectiveness of six thermal and microwave techniques of absolute palaeointensity determination applied to lava samples from Mount Etna (Sicily) that acquired their thermoremanence (TRM) in a known geomagnetic field. The application of a single alternating field demagnetisation treatment prior to each measurement in a standard Thellier experiment is demonstrated to be beneficial: increasing the quality of the results and making the analysis simpler. A new quasi-perpendicular (QP) method dramatically improves the linearity of Arai plots by reducing or altogether eliminating non-ideal effects due to multidomain (MD) grains. Two broad types of sample were encountered by this study and the QP method is the only one capable of producing accurate measurements from them both. Its ease of use, speed, and increased reliability should allow it to replace standard double heating methods in studies such as these where laboratory alteration can be detected by other means than pTRM checks. The results of experiments performed using a microwave palaeointensity system provide further proof that the microwave (de)magnetisation process is equivalent to conventional thermal excitation. They also demonstrate that microwave experiments are subject to the same risks as conventional experiments when performed on samples containing MD grains. The behaviour of the samples in both the thermal and microwave experiments is in good agreement with a recently proposed model of MD TRM which is based on first-order symmetry of the remagnetisation process.
ISSN: 0012-821X

hal-00407671
https://hal.archives-ouvertes.fr/hal-00407671
DOI : 10.1016/j.epsl.2007.03.016

Éditeur(s) : HAL CCSD Royal Society of Chemistry
Résumé : International audience
A versatile sol-gel route has been developed for the preparation of hierarchical porous silica membrane material with highly dispersed platinum nanoparticles (Pt-NPs). The outstanding feature of the "one pot" synthesis developed in this work lies in the successful preparation of a stable complex suspension made of silica sol, multi-scale porogens and Pt nanoparticles. The multi-scale porogens were based on non-ionic triblock copolymers and aqueous latex suspension to create mesopores and macropores, respectively, with finely tuned pore size and organization. For further functionalization of the membranes, Pt nanoparticles of about 4 nm in diameter were prepared by irradiating with microwaves (MW) the Pt precursors added in the starting suspension. This original path is suggested to enable a pre-organization of Pt nanoparticles in the ordered mesoporous structure. The suspensions were then deposited as thin films on either dense or macroporous supports, and further thermally treated at 450°C to remove the porogen units. Hierarchical porous layers composed of micropores (<2 nm), ordered mesopores (∼4 nm) and macropores (∼70 nm) with or without Pt were prepared and characterized. The resulting membranes are foreseen to exhibit great potential as multifunctional membranes for gas separation coupled with catalytic reaction. © The Royal Society of Chemistry 2008.
ISSN: 0959-9428

hal-01680586
https://hal.univ-antilles.fr/hal-01680586
DOI : 10.1039/b807029f

Éditeur(s) : American Geophysical Union
Résumé : Microwave Sea Surface Salinity (SSS) measurements can be performed by isolating the emissivity response to salinity changes from numerous geophysical effects, including surface temperature and wind waves. At L-band frequencies (1 to 2 GHz), the sensitivity to SSS is sufficient but it falls off quickly as frequency is increased. Nevertheless, methods using higher microwave frequencies with much lower SSS sensitivity than at L band, can already be tested. In particular, combining 6 and 10 GHz data in vertical polarization efficiently minimizes sea surface roughness and thermal impacts. Using AMSR-E data, the retrieved bi-monthly maps of SSS at 0.5 degrees resolution over the region of the Amazon plume show relative accuracy in-line with the future L-band dedicated mission objectives. Citation: Reul, N., S. Saux-Picart, B. Chapron, D. Vandemark, J. Tournadre, and J. Salisbury (2009), Demonstration of ocean surface salinity microwave measurements from space using AMSR-E data over the Amazon plume, Geophys. Res. Lett., 36, L13607, doi:10.1029/2009GL038860.
Geophysical Research Letters ( GRL ) (0094-8276) (American Geophysical Union), 2009-07 , Vol. 36 , P. 1-5

Droits : 2009. American Geophysical Union. All Rights Reserved
http://archimer.ifremer.fr/doc/2009/publication-6620.pdf
DOI:10.1029/2009GL038860
http://archimer.ifremer.fr/doc/00000/6620/

Éditeur(s) : IEEE
Résumé : Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission addressing the challenge of measuring sea surface salinity from space. It uses an L-band microwave interferometric radiometer with aperture synthesis (MIRAS) that generates brightness temperature images, from which both geophysical variables are computed. The retrieval of salinity requires very demanding performances of the instrument in terms of calibration and stability. This paper highlights the importance of ocean salinity for the Earth's water cycle and climate; provides a detailed description of the MIRAS instrument, its principles of operation, calibration, and image-reconstruction techniques; and presents the algorithmic approach implemented for the retrieval of salinity from MIRAS observations, as well as the expected accuracy of the obtained results.
Proceedings of the IEEE (0018-9219) (IEEE), 2010-05 , Vol. 98 , N. 5 , P. 649-665

Droits : 2010 IEEE – All Rights Reserved
http://archimer.ifremer.fr/doc/00004/11482/8066.pdf
DOI:10.1109/JPROC.2009.2033096
http://archimer.ifremer.fr/doc/00004/11482/

Éditeur(s) : Ieee-inst Electrical Electronics Engineers Inc
Résumé : We validate Soil Moisture and Ocean Salinity (SMOS) sea surface salinity (SSS) retrieved during August 2010 from the European Space Agency SMOS processing. Biases appear close to land and ice and between ascending and descending orbits; they are linked to image reconstruction issues and instrument calibration and remain under study. We validate the SMOS SSS in conditions where these biases appear to be small. We compare SMOS and ARGO SSS over four regions far from land and ice using only ascending orbits. Four modelings of the impact of the wind on the sea surface emissivity have been tested. Results suggest that the L-band brightness temperature is not linearly related to the wind speed at high winds as expected in the presence of emissive foam, but that the foam effect is less than previously modeled. Given the large noise on individual SMOS measurements, a precision suitable for oceanographic studies can only be achieved after averaging SMOS SSS. Over selected regions and after mean bias removal, the precision on SSS retrieved from ascending orbits and averaged over 100 km $times$ 100 km and 10 days is between 0.3 and 0.5 pss far from land and sea ice borders. These results have been obtained with forward models not fitted to satellite L-band measurements, and image reconstruction and instrument calibration are expected to improve. Hence, we anticipate that deducing, from SMOS measurements, SSS maps at 200 km $times$ 200 km, 10 days resolution with an accuracy of 0.2 pss at a global scale is not out of reach.
Ieee Transactions On Geoscience And Remote Sensing (0196-2892) (Ieee-inst Electrical Electronics Engineers Inc), 2012-05 , Vol. 50 , N. 5 , P. 1662-1675

Droits : 2012 IEEE
http://archimer.ifremer.fr/doc/00074/18557/16108.pdf
DOI:10.1109/TGRS.2012.2184546
http://archimer.ifremer.fr/doc/00074/18557/

Éditeur(s) : Amer Geophysical Union
Résumé : The temporal evolution and spatial distribution of surface salinity and colored detrital matter (cdm) were evaluated within and adjacent to the Amazon River Plume. Study objectives were as follows: first, to document the spatial coherence between Amazon discharge, salinity, cdm, and the nature of the salinity-cdm relationship; second, to document the temporal and spatial variability of cdm along the trajectory of the low-salinity Amazon Plume, and third, to explore the departure of cdm from conservative mixing behavior along the plume trajectory into the open ocean. Time series (2003-2007) of surface salinity estimated using the Advanced Microwave Scanning Radiometer-Earth Observing System and corresponding satellite cdm absorption (acdm) data documented a plume of freshened, colored water emanating from the Amazon. Salinity and acdm were generally coherent, but there were regions in which spatial patterns of salinity and acdm did not coincide. Salinity was oppositely phased with discharge, whereas acdm was in phase but lagged discharge and typically remained high after maximum discharge. Along the river plume trajectory, acdm was inversely correlated with salinity, yet there was considerable deviation from conservative mixing behavior during all seasons. Positive anomalies in a linear relationship between salinity and acdm corresponded to areas of enhanced satellite-retrieved net primary productivity, suggesting the importance of phytoplankton biomass or its subsequent remineralization as a source of cdm. Negative anomalies tended to predominate at the distal sections of the plume trajectories, an observation consistent with the process of photo-oxidation of cdm over observed time scales of days to weeks.
Journal Of Geophysical Research-oceans (0148-0227) (Amer Geophysical Union), 2011-07 , Vol. 116 , N. C00H02 , P. 14 p.

Droits : 2011 American Geophysical Union. All Rights Reserved.
http://archimer.ifremer.fr/doc/00041/15218/12593.pdf
DOI:10.1029/2011JC006989
http://archimer.ifremer.fr/doc/00041/15218/

Éditeur(s) : Taylor & Francis Ltd
Résumé : A new method is developed to estimate daily turbulent airsea fluxes over the global ocean on a 0.25 degrees grid. The required surface wind speed (w(10)) and specific air humidity (q(10)) at 10m height are both estimated from remotely sensed measurements. w(10) is obtained from the SeaWinds scatterometer on board the QuikSCAT satellite. A new empirical model relating brightness temperatures (T-b) from the Special Sensor Microwave Imager (SSM/I) and q(10) is developed. It is an extension of the author's previous q(10) model. In addition to T-b, the empirical model includes sea surface temperature (SST) and airsea temperature difference data. The calibration of the new empirical q(10) model utilizes q(10) from the latest version of the National Oceanography Centre airsea interaction gridded data set (NOCS2.0). Compared with mooring data, the new satellite q(10) exhibits better statistical results than previous estimates. For instance, the bias, the root mean square (RMS), and the correlation coefficient values estimated from comparisons between satellite and moorings in the northeast Atlantic and the Mediterranean Sea are 0.04gkg(1), 0.87gkg(1), and 0.95, respectively. The new satellite q(10) is used in combination with the newly reprocessed QuikSCAT V3, the latest version of SST analyses provided by the National Climatic Data Center (NCDC), and 10m air temperature estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses (ERA-Interim), to determine three daily gridded turbulent quantities at 0.25 degrees spatial resolution: surface wind stress, latent heat flux (LHF), and sensible heat flux (SHF). Validation of the resulting fields is performed through a comprehensive comparison with daily, in situ values of LHF and SHF from buoys. In the northeast Atlantic basin, the satellite-derived daily LHF has bias, RMS, and correlation of 5Wm(2), 27Wm(2), and 0.89, respectively. For SHF, the statistical parameters are 2Wm(2), 10Wm(2), and 0.94, respectively. At global scale, the new satellite LHF and SHF are compared to NOCS2.0 daily estimates. Both daily fluxes exhibit similar spatial and seasonal variability. The main departures are found at latitudes south of 40 degrees S, where satellite latent and sensible heat fluxes are generally larger.
International Journal Of Remote Sensing (0143-1161) (Taylor & Francis Ltd), 2013-07 , Vol. 34 , N. 14 , P. 5243-5261

Droits : 2013 Taylor & Francis
http://archimer.ifremer.fr/doc/00137/24825/23575.pdf
DOI:10.1080/01431161.2013.787502
http://archimer.ifremer.fr/doc/00137/24825/

Éditeur(s) : ESA Publication
Résumé : Satellite remote sensing has emerged as an essential and necessary observing system to acquire global information about the state of the ocean. Complemented with in situ observing networks, the ultimate goals are to be able to make accurate estimates of selected key sets of geophysical variables, with the intention of either making operational predictions across time and spatial boundaries, or advancing fundamental knowledge through development of empirical relationships and theoretical models. For satellite oceanography, improvements are then constantly being sought in our understandings of the geophysical processes, the sensor physics, the electromagnetic and microwave properties and interactions at the complex air-sea interface. Challenges appear as unlimited as the variety of sea surface dynamics and boundary layer meteorological conditions with their broad range of spatial and temporal scales across the globe. To face these challenges, numerous efforts took places over the passed decade to build an ever-increasing quality, quantity, duration and integration of ocean observations. In parallel, simulation capabilities largely improved. All these efforts are then all critically calling for improved methodologies to better structure the wealth of information that is made readily accessible. This latter aspect is a very demanding new component for future multidisciplinary scientific research. Major innovations to consolidate sensor data repositories, to automate tailored queries, to extract, reveal and quantify relationships will then closely associate computer science developments and applied statistics with comprehensive theoretical and experimental thematic studies.
Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society (ESA Publication), 2010

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00029/14046/11241.pdf
DOI:10.5270/OceanObs09.pp.12
http://archimer.ifremer.fr/doc/00029/14046/

Éditeur(s) : Springer
Résumé : While it is well known that the ocean is one of the most important component of the climate system, with a heat capacity 1,100 times greater than the atmosphere, the ocean is also the primary reservoir for freshwater transport to the atmosphere and largest component of the global water cycle. Two new satellite sensors, the ESA Soil Moisture and Ocean Salinity (SMOS) and the NASA Aquarius SAC-D missions, are now providing the first space-borne measurements of the sea surface salinity (SSS). In this paper, we present examples demonstrating how SMOS-derived SSS data are being used to better characterize key land–ocean and atmosphere–ocean interaction processes that occur within the marine hydrological cycle. In particular, SMOS with its ocean mapping capability provides observations across the world’s largest tropical ocean fresh pool regions, and we discuss from intraseasonal to interannual precipitation impacts as well as large-scale river runoff from the Amazon–Orinoco and Congo rivers and its offshore advection. Synergistic multi-satellite analyses of these new surface salinity data sets combined with sea surface temperature, dynamical height and currents from altimetry, surface wind, ocean color, rainfall estimates, and in situ observations are shown to yield new freshwater budget insight. Finally, SSS observations from the SMOS and Aquarius/SAC-D sensors are combined to examine the response of the upper ocean to tropical cyclone passage including the potential role that a freshwater-induced upper ocean barrier layer may play in modulating surface cooling and enthalpy flux in tropical cyclone track regions.
Surveys In Geophysics (0169-3298) (Springer), 2014-05 , Vol. 35 , N. 3 , P. 681-722

Droits : Springer Science+Business Media Dordrecht 2013
http://archimer.ifremer.fr/doc/00152/26334/24430.pdf
DOI:10.1007/s10712-013-9244-0
http://archimer.ifremer.fr/doc/00152/26334/

Éditeur(s) : Copernicus Gesellschaft Mbh
Résumé : The sea surface salinity (SSS) measured from space by the Soil Moisture and Ocean Salinity (SMOS) mission has recently been revisited by the European Space Agency first campaign reprocessing. We show that, with respect to the previous version, biases close to land and ice greatly decrease. The accuracy of SMOS SSS averaged over 10 days, 100 x 100 km(2) in the open ocean and estimated by comparison to ARGO (Array for Real-Time Geostrophic Oceanography) SSS is on the order of 0.3-0.4 in tropical and subtropical regions and 0.5 in a cold region. The averaged negative SSS bias (-0.1) observed in the tropical Pacific Ocean between 5 degrees N and 15 degrees N, relatively to other regions, is suppressed when SMOS observations concomitant with rain events, as detected from SSM/Is (Special Sensor Microwave Imager) rain rates, are removed from the SMOS-ARGO comparisons. The SMOS freshening is linearly correlated to SSM/Is rain rate with a slope estimated to -0.14 mm(-1) h, after correction for rain atmospheric contribution. This tendency is the signature of the temporal SSS variability between the time of SMOS and ARGO measurements linked to rain variability and of the vertical salinity stratification between the first centimeter of the sea surface layer sampled by SMOS and the 5 m depth sampled by ARGO. However, given that the whole set of collocations includes situations with ARGO measurements concomitant with rain events collocated with SMOS measurements under no rain, the mean -0.1 bias and the negative skewness of the statistical distribution of SMOS minus ARGO SSS difference are very likely the mean signature of the vertical salinity stratification. In the future, the analysis of ongoing in situ salinity measurements in the top 50 cm of the sea surface and of Aquarius satellite SSS are expected to provide complementary information about the sea surface salinity stratification.
Ocean Science (1812-0784) (Copernicus Gesellschaft Mbh), 2013 , Vol. 9 , N. 1 , P. 183-192

Droits : Author(s) 2013. CC Attribution 3.0 License.
http://archimer.ifremer.fr/doc/00139/25073/23161.pdf
DOI:10.5194/os-9-183-2013
http://archimer.ifremer.fr/doc/00139/25073/