A method to derive satellite PAR albedo time series over first-year sea ice in the Arctic Ocean

Deriving sea ice albedo from spaceborne platforms is of interest to model the propagation of the photosynthetically available radiation (PAR) through Arctic sea ice. We show here that use of the Moderate Resolution Imaging Spectroradiometer (MODIS) operational surface reflectance satellite product to derive albedo in the PAR spectral range is possible. To retrieve PAR albedo from the remote sensing surface reflectance, we trained a predictive model based on a principal component analysis with in situ and simulated data. The predictive model can be applied to first-year sea ice surfaces such as dry snow, melting snow, bare ice and melt ponds. Based on in situ measurements and the prescribed atmospheric correction uncertainty, the estimated PAR albedo had a mean absolute error of 0.057, a root mean square error of 0.074 and an R2 value of 0.91. As a demonstration, we retrieved PAR albedo on a 9-km2 area over late spring and early summer 2015 and 2016 at a coastal location in Baffin Bay, Canada. On-site measurements of PAR albedo, melt pond fraction and types of precipitation were used to examine the estimated PAR albedo time series. The results show a dynamic and realistic PAR albedo time series, although clouds remained the major obstacle to the method. This easy-to-implement model may be used for the partitioning of PAR in the Arctic Ocean and ultimately to better understand the dynamics of marine primary producers.publishedVersio

Green Edge ice camp campaigns : understanding the processes controlling the under-ice Arctic phytoplankton spring bloom

The Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797∘ N, 63.7895∘ W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea-ice cover from the surface to the bottom (at 360 m depth) to better understand the factors driving the PSB. Key variables, such as conservative temperature, absolute salinity, radiance, irradiance, nutrient concentrations, chlorophyll a concentration, bacteria, phytoplankton and zooplankton abundance and taxonomy, and carbon stocks and fluxes were routinely measured at the ice camp. Meteorological and snow-relevant variables were also monitored. Here, we present the results of a joint effort to tidy and standardize the collected datasets, which will facilitate their reuse in other Arctic studies

Diverticule de Zenker (choix thérapeutique en 2010)

CAEN-BU Médecine pharmacie (141182102) / SudocSudocFranceF

Functional genomics and proteomic approaches for the study of gamete formation and viability in farmed finfish

International audienceThe sustained mass production of alevins in finfish aquaculture requires a deep understanding of the biological processes controlling gametogenesis, which ultimately will determine the quality of eggs and sperm. Functional genomics and proteomics technologies have been recently developed, expanding the scope of biological investigation from studying single genes or proteins to studying potentially all genes and proteins at once in a systematic manner The application of these methods in aquaculture is still in its infancy, especially with regard to the study of fish reproduction, but in the near future its impact is envisaged because of their potential to uncover the complex genetic control of gamete formation. Here, we review recent studies employing high-throughput genomics and proteomics approaches that have been carried out to investigate the global pattern of gene and protein expression during finfish gametogenesis. The results of these studies have already identified a number of novel genes, maternal molecules, and proteins that may be essential during spermatogenesis, oogenesis, and early embryogenesis, thus greatly contributing to our current knowledge of the molecular mechanisms underlying egg and sperm formation. The full potential of genomics to uncover the molecular basis of fish gametogenesis is about to be unleashed with the sequencing of the genome and transcriptome of additional species and the development of methods to elucidate gene function

Aplicación de la genómica funcional y proteómica en el estudio de la reproducción y calidad de los gametos de teleósteos

International audienc

Aplicación de la genómica funcional y proteómica en el estudio de la reproducción y calidad de los gametos de teleósteos

47 pages, 3 figures[EN] The sustained mass production of alevins in finfish aquaculture requires a deep understanding of the biological processes controlling gametogenesis which ultimately will determine de quality of eggs and sperm. Functional genomics and proteomics technologies have been recently developed expanding the scope of biological investigation from studying single genes or proteins to studying potentially all genes and proteins at once, in a systematic manner. The application of these methods in aquaculture is still in its infancy, especially with regard to the study of fish reproduction, but in the near future its impact is envisaged because of the potential to uncover the complex genetic control of gamete formation in finfish. Here, we review recent studies employing high-throughput genomic and proteomic approaches that have been carried out to investigate the global pattern of gene and protein expression during finfish gametogenesis. The results of these initial works have already identified a number of novel genes, maternal molecules and proteins that are essential during fish spermatogenesis, oogenesis and early embryogenesis, thus greatly contributing to our current knowledge of the molecular mechanisms underlying egg and sperm formation. However, the full potential of genomics to uncover the molecular basis of finfish gametogenesis is about to be unleashed with the sequencing of the genome and transcriptome of additional species and the development of methods to elucidate gene function[ES] La producción industrial de alevines en acuicultura requiere un conocimiento profundo de los procesos biológicos que controlan la gametogénesis, los cuales en última instancia determinarán la calidad de los gametos. Las tecnologías de genómica funcional y proteómica, recientemente desarrolladas, han aumentado el alcance de la investigación biológica desde el estudio de genes y proteínas individuales al estudio del modelo de expresión de todos los genes y proteínas simultáneamente de una forma sistemática. La aplicación de estos métodos en acuicultura todavía es muy reciente, especialmente en la investigación de la reproducción de teleósteos. No obstante, es muy posible que en los próximos años estas metodologías tengan un gran impacto por el potencial que poseen para descubrir el complejo control genético de la formación de gametos. En este capítulo, se analizan estudios recientes que han empleado estrategias genómicas y proteómicas para investigar el modelo global de expresión génica y de proteínas durante la gametogénesis de teleósteos. Los resultados de estos primeros trabajos ya han identificado un gran número de genes, moléculas de origen materno y proteínas que parecen ser esenciales durante la oogénesis, espermatogénesis y el desarrollo embrionario inicial de teleósteos. Estos hallazgos están contribuyendo de forma muy importante al conocimiento sobre los mecanismos moleculares implicados en la formación de los huevos y esperma en peces. Sin embargo, la explotación de todo el potencial de la genómica para descubrir la base molecular de la gametogénesis de teleósteos está a punto de ser una realidad con la secuenciación del genoma y transcriptoma de especies de interés comercial y el desarrollo de métodos para identificar la función de los genesPeer Reviewe

MCM-41 silica monoliths with independent control of meso and macroporosity

International audienc