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© 2017 Elsevier Ltd Mechanistic models rely on specification of parameters representing biophysical traits and process rates such as phytoplankton, zooplankton and seagrass growth and respiration rates, organism sizes, stoichiometry, light, temperature and nutrient responses, nutrient-specific excretion rates and detrital stoichiometry and decay rates. Choosing suitable values for these parameters is difficult. Current practise is problematic. This paper presents a resource designed to facilitate an evidence-based approach to parameterisation of aquatic ecosystem models. An online tool is provided which collates relevant, published biological trait and biogeochemical rate observations from many sources and allows users to explore, filter and convert these data in a consistent, reproducible way, to find parameter values and calculate probability distributions. Using this information within a traditional or Bayesian paradigm should provide improved understanding of the uncertainty and predictive capacity of aquatic ecosystem models and provide insight into current sources of structural error in models.

Dimethylsulfide (DMS) is biologically produced in the surface ocean and is the dominant natural source of sulfur to the atmosphere. Although DMS is an algal by-product, the ratio of DMS to chlorophyll (DMS:Chl) varies widely in the surface ocean. This is presumably because dimethylsulfoniopropionate (DMSP), the major precursor of DMS, DMSP-lyases, which catalyze the conversion of DMSP to DMS, and Chl vary as well with taxonomic composition than with the physiological state of the algal assemblage. Here we use remote sensing of Chl and phytoplankton dominance from PHYSAT with in-situ measured DMS concentrations to assess on an unprecedented spatial scale the affect of species composition on the DMS:Chl ratio in the surface ocean. Meridional distributions at 22° W in the Atlantic, and 95° W and 110° W in the Pacific, showed the same marked drop in DMS:Chl ratios near the equator, down to few mmol g−1, yet the basins exhibited different species dominance signatures. Hence, our results suggest that species composition was of secondary importance in controlling DMS and DMS:Chl variations in equatorial upwellings as well as physiological shifts in algal DMS production since mixed layer growth conditions (i.e., nutrient stress, temperature and light) were relatively homogeneous over the eastern equatorial Pacific. In the Indian sector of the Southern Ocean, warm core eddies with contrasting PHYSAT signatures displayed similar DMS levels. However, DMS:Chl ratios in eddies dominated by Synechococcus (SYN) were about 50% lower than that found in eddies showing nanoeucayotes or Phaeocystis-like signatures. DMS:Chl ratios varied with latitude in SYN dominated regions with ratios at low latitudes (away from equatorial upwellings) about twice that found at high northern and southern latitudes. This is the sole piece of coherent observations which indicates that species composition and growth conditions affect the large-scale dynamics of the DMS:Chl ratio. Overall, it appears that the DMS:Chl ratio is not consistent within specific phytoplankton groups determined from space. So DMS concentrations can not be derived from water-leaving radiance spectra obtained simultaneously from ocean color sensor measurements of Chl concentrations and dominant phytoplankton functional types. To proceed with the global investigation and better discriminate between factors affecting DMS:Chl ratios in the surface ocean, we recommend the use of PHYSAT records with higher spatial resolution in conjunction with other satellite products (e.g. particulate backscattering coefficients and indices of phytoplankton physiology and bloom status).

The phytoplankton bloom that develops over the Kerguelen plateau following natural input of iron is analysed on a regional and seasonal scale. The relation between chlorophyll, bathymetry, and surface advection fields is not as obvious as it first appears from largescale annual mean field. The high chlorophyll biomass does not always correspond with the shallowest water, and there are portions of the plateau, which persistently exhibit low chlorophyll. Despite this complex dynamic, a one-dimensional model calibrated for HNLC (high-nutrient low-chlorophyll) region is able to capture the observed increase in chlorophyll by increasing the deep iron concentration. The elemental budget shows similarity in terms of carbon, nitrogen, and silicon but differences in terms of iron with the budget calculated during the mission. This discrepancy either has its origin in the structure of the iron cycling in the model or in the temporal scarcity of data that could only be collected during the summer months. In the model, flexibility of the Fe/C ratio associated with high Fe export and input fluxes prevents high carbon sequestration efficiency. This first insight with remote sensing data and the model allows the validation of some of the key mechanisms of natural iron fertilization and exposes problems that will need to be solved to have a complete biogeochemical diagnostic of this natural iron fertilization.

The authors report a case of subacute myelocytic leukemia presenting some severe aspects. The cytogenetic findings show the Philadelphia chromosome ; t (9-22) and a second translocation between the chromosome 12, and the other chromosome 9 : t (9-12). They think that this second translocation represents a supplementary cytogenetic argument for the isolation of "Subacute myeloid Leukemia with Philadelphia chromosome" within chronic myeloid Leukemia.