The use of algorithms to predict surface seawater dimethyl sulphide concentrations in the SE Pacific, a region of steep gradients in primary productivity, biomass and mixed layer depth

Dimethyl sulphide (DMS) is an important precursor of cloud condensation nuclei (CCN), particularly in the remote marine atmosphere. The SE Pacific is consistently covered with a persistent stratocumulus layer that increases the albedo over this large area. It is not certain whether the source of CCN to these clouds is natural and oceanic or anthropogenic and terrestrial. This unknown currently limits our ability to reliably model either the cloud behaviour or the oceanic heat budget of the region. In order to better constrain the marine source of CCN, it is necessary to have an improved understanding of the sea-air flux of DMS. Of the factors that govern the magnitude of this flux, the greatest unknown is the surface seawater DMS concentration. In the study area, there is a paucity of such data, although previous measurements suggest that the concentration can be substantially variable. In order to overcome such data scarcity, a number of climatologies and algorithms have been devised in the last decade to predict seawater DMS. Here we test some of these in the SE Pacific by comparing predictions with measurements of surface seawater made during the Vamos Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) in October and November of 2008. We conclude that none of the existing algorithms reproduce local variability in seawater DMS in this region very well. From these findings, we recommend the best algorithm choice for the SE Pacific and suggest lines of investigation for future work

Topological aspects of Hurewicz tests for the difference hierarchy

We generalize the Baire Category Theorem to the Borel and difference hierarchies, i.e. if Г is any of the classes Σξ⁰, Пξ⁰, Dη(Σξ⁰) or Ďη(Σξ⁰) we find a representative set Pг ∊ Г and a Polish topology τг such that for every A ∊ Ѓ from some assumption on the size of A ∩ Pг we can deduce that A\ Pг is of second category in the topology τг. This allows us to distinguish the levels of the Borel and difference hierarchies via Baire category. We also present some typical Baire Category Theorem-like applications of the results

Net primary productivity estimates and environmental variables in the Arctic Ocean; an assessment of coupled physical-biogeochemical models

The relative skill of 21 regional and global biogeochemical models was assessed in terms of how well the models reproduced observed net primary productivity (NPP) and environmental variables such as nitrate concentration (NO (sub 3) ), mixed layer depth (MLD), euphotic layer depth (Z (sub eu) ), and sea ice concentration, by comparing results against a newly updated, quality-controlled in situ NPP database for the Arctic Ocean (1959-2011). The models broadly captured the spatial features of integrated NPP (iNPP) on a pan-Arctic scale. Most models underestimated iNPP by varying degrees in spite of overestimating surface NO (sub 3) , MLD, and Z (sub eu) throughout the regions. Among the models, iNPP exhibited little difference over sea ice condition (ice-free versus ice-influenced) and bottom depth (shelf versus deep ocean). The models performed relatively well for the most recent decade and toward the end of Arctic summer. In the Barents and Greenland Seas, regional model skill of surface NO (sub 3) was best associated with how well MLD was reproduced. Regionally, iNPP was relatively well simulated in the Beaufort Sea and the central Arctic Basin, where in situ NPP is low and nutrients are mostly depleted. Models performed less well at simulating iNPP in the Greenland and Chukchi Seas, despite the higher model skill in MLD and sea ice concentration, respectively. iNPP model skill was constrained by different factors in different Arctic Ocean regions. Our study suggests that better parameterization of biological and ecological microbial rates (phytoplankton growth and zooplankton grazing) are needed for improved Arctic Ocean biogeochemical modelin

Studies of CD38 in chronic lymphocytic leukaemia

This Thesis consists of 4 experimental Chapters preceded by a General Introduction and followed by a brief section dealing with conclusions and future. In Chapter 1, the prognostic value of CD38 and the relationship between surface expression of this molecule and IgVH mutation are considered. It is shown that surface CD38 expression on CLL cells is highly predictive of nonhypermutated IgVH gene mutation status, while CD38 negativity lacks such predictive value, since IgVH mutated and uninutated cases occur with approximately equal frequency in this subgroup. It is also shown, in agreement with the literature, that CD38 expression is associated with shorter survival and male preponderance. Abundant data are available on the intracellular expression of CD38 in other cell types, but not in CLL. Therefore, Chapter 2 deals with intracellular CD38 in CLL cells and with the different molecular forms expressed in sCD38+ and sCD38- CLL clones. Using a number of different techniques, it is shown that CD38 is expressed intracellularly in all CLL cells irrespectively of the surface expression of the molecule. In keeping with these findings, CD38 mRNA was found in both sCD38+ and sCD38- CLL clones at comparably low levels. It is documented by Western blotting and immunoprecipitation that CLL cells express, in addition to the 45 kD CD38 monomer, other molecular forms of 27, 60 and 205 M Among these, the high molecular weight molecule probably represents a tetrameric form of CD38 and is described in CLL for the first time. A main difference found between the sCD38+ and sCD38- clones was the almost complete absence of the 45 kD monomeric form in the sCD38- clones. An unexpected and interesting finding was a surface immunoreactivity with the anti- CD38 antibody Ab-4 on CLL cells previously classified as IICD38 negative" with the HB-7 antibody. In Chapter 3, the topology of different molecular forms of CD38 is studied further and their enzymatic functions are examined. By subcellular fractionation it is demonstrated that the tetrameric form of CD38 is most abundant in the membrane fraction. Surface radioiodination of CLL cells indicated, for the first time that the main forms of CD38 on the surface of CLL cells are the 45 kD and the -205 kD molecules. The 205 kD molecule was demonstrable on both sCD38+ and sCD38- cells, while the 45 kD molecule was present only on sCD38+ cells. Surface forms of CD38 on CLL cells were characterised further by enzymatic assays performed before and after protease digestion of surface proteins. Results indicated that surface forms are the major sources of CD38 enzymatic activity in CLL cells. Total cyclase and hydrolase activities were also compared in sCD38+ and sCD38- CLL cells and it was shown that both cell types possess these enzymatic functions, although activities were lower in sCD38- cells. It seems likely that the 45 kD molecule (probably present as non-covalently linked dimers) is responsible for the greater enzymatic activity of sCD38+ clones. Enzymatic assays performed after recovering proteins from polyacrylamide gels indicated that eluates from the HMW (>116 kD) section of the gels containing the putative CD38 tetramers have both cyclase and hydrolase activities.Chapter 4 addresses the question of why CD38-positive CLL is characterised by progressiveness and poor outcome. Since CD38 has a welldocumented role in cell cycle regulation and cell proliferation in other cell types, it was hypothesized that a similar linkage might be also present in CLL, contributing to the the adverse clinical outcome. To test this hypothesis, CLL cells were co-stained for surface CD38 and nuclear Ki-67 following a saponinbased permeabilization procedure. CLL clones classified as CD38+ expressed significantly higher levels of Ki-67 than did sCD38- clones. Clones classified as Ki-67+ (>5%) expressed significantly higher levels of CD38 than did Ki-67- ones. Relating surface CD38% and nuclear Ki-67% revealed a linear correlation between these two parameters. Also, the Ki-67+ subpopulation within a given CLL clone expressed significantly higher CD38 values than did the Ki-67- subpopulation. Furthermore, larger CLL cells showed significantly higher Ki-67 values than small CLL lymphocytes. Finally, CD38 immunoreactivity in CLL lymph node sections was found to be strongest in the proliferation centres. These data therefore indicate, for the first time, that surface CD38 expression is a marker of cell cycling activity in CLL and help to explain the adverse prognosis of CD38+ CLL and CLUPL

Marine polymer-gels’ relevance in the atmosphere as aerosols and ccn

Marine polymer gels play a critical role in regulating ocean basin scale biogeochemical dynamics. This brief review introduces the crucial role of marine gels as a source of aerosol particles and cloud condensation nuclei (CCN) in cloud formation processes, emphasizing Arctic marine microgels. We review the gel’s composition and relation to aerosols, their emergent properties, and physico-chemical processes that explain their change in size spectra, specifically in relation to aerosols and CCN. Understanding organic aerosols and CCN in this context provides clear benefits to quantifying the role of marine nanogel/microgel in microphysical processes leading to cloud formation. This review emphasizes the DOC-marine gel/aerosolized gel-cloud link, critical to developing accurate climate models

CERTIFICATION REPORT A set of three plasmid DNA calibration solutions bearing a porcine-specific DNA fragment Certified Reference Materials: ERM®-AD483a, ERM®-AD483b, ERM®-AD483c

This report describes the preparation and characterisation of a set of plasmid solutions, ERM-AD483a, ERM-AD483b and ERM-AD483c. The materials were produced in accordance with ISO Guide 34:2009 [1]. A DNA fragment specific for the identification of a porcine target was cloned into a pUC18 vector to construct the pIRMM-0104 plasmid. The nucleic acid sequence of the entire pIRMM-0104 plasmid was determined by dye terminator cycle sequencing. The plasmid was eluted in TElow buffer, and its concentration was measured by ultraviolet (UV) spectrophotometry. Afterwards, it was gravimetrically diluted to three different concentration levels. The plasmid copy number concentration of the three concentration levels were certified by digital and droplet digital quantitative polymerase chain reaction methods, dPCR and ddPCR respectively. In addition, between-unit homogeneity, as well as short-term and long-term stability was assessed in accordance with ISO Guide 35:2006 [2]. The materials are intended for the determination of a cut-off value to discriminate positive samples (containing the porcine target sequence) from negative samples by quantitative PCR as defined in the Standard Operating Procedure of the EU Reference Laboratory for Animal proteins (EURL-AP) according to Commission Regulation (EU) No 51/2013 [3, 4]. As any certified reference material (CRM), ERM-AD483 can also be used for control charts or validation studies. The CRM is available as a set of three vials, each containing at least 1 mL of plasmid solution. The minimum amount of sample to be used is 4 µL.JRC.D.2-Standards for Innovation and sustainable Developmen