Grounding for an Enterprise Computing Nomenclature Ontology

We aim to lay the basis for a unified architecture for enterprise computer nomenclatures by providing the grounding ontology based upon the BORO Foundational Ontology. We start to lower two significant barriers within the computing community to making progress in this area; a lack of a broad appreciation of the nature and practice of nomenclature and a lack of recognition of some specific technical, philosophical issues that nomenclatures raise. We provide an overview of the grounding ontology and how it can be implemented in a system. We focus on the issue that arises when tokens lead to the overlap of the represented domain and its system representation – system-domain-overlap – and how this can be resolved

Chemical changes and superoxide production in thylakoid membranes under water stress

Sunflower seedlings (Helianthus annuus cv. Isabel) subjected to a moderate level of water stress showed a reduced growth and a 0.1 MPa osmotic adjustment came into play. Thylakoid membranes isolated from stressed leaves showed decreased chlorophyll (Chl) and protein contents but the Chl a/Chl b and protein/Chl ratios were unchanged. Water stress caused a preferential hydrolysis in thylakoid proteins: the hydrophilic to hydrophobic protein ratio increased from 0.8 in the control to 4.5 in the stressed plants. However, the degree of unsaturation was unchanged and the electron spin resonance (ESR) measurements did not show an increased level of superoxide radical production by photosynthetic membranes

Acclimation to low water potential determines changes in membrane fatty acid composition and fluidity in potato cells

Potato (Solanum tuberosum) cells were gradually acclimated to grow at low water potential created by addition of increasing concentrations of polyethylene glycol (PEG) 8000 to the nutrient medium. While growth of cells abruptly transferred into a medium containing 20% PEG was dramatically inhibited, under the same stress intensity gradually acclimated cells were able to sustain active growth similarly to control unstressed cells. Gradual acclimation allowed the maintenance of normal cellular and subcellular membrane structure at an osmotic potential of -2.3 MPa, which caused extended membrane disruption when applied to non-acclimated control cells. Analysis of fatty acids (FAs) from control and acclimated cells revealed that the mol percentage composition of the major extra-plastidial phospholipids (PLs) was basically unchanged, but both phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were more saturated in acclimated cells. The decrease in unsaturation occurred primarily at the expense of linoleic acid (18:2) in the PE fraction. A significant increase in the percentage content of palmitic acid (16:0) of the PE fraction was also detected in acclimated cells. Membrane microviscosity, as determined by diphenyl-hexatriene (DPH) labelling, was higher in PEG-acclimated cells, as expected from the lower degree of unsaturation of membrane FAs found in acclimated cells. The steady-state transcript levels of a Δ9-stearoyl-acyl carrier protein-desaturase and a Δ12-oleoyl-desaturase gene decreased in acclimated cells, suggesting that the variation in the level of FA unsaturation was at least partially associated with down-regulation of the expression of these genes