Light Interception and Photosynthetic Efficiency in Some Glasshouse Crops

Productivity of glasshouse crops is strongly limited by lightreceipt, and efficient interception and use of light in photosynthesisis correspondingly important. Mature row crop canopies of cucumberand tomato intercepted about 76% of the light incident on theirupper surfaces; about 18% was lost through gaps between therows. Light transmitted through the entire depth of the canopywas reflected back by white plastic on the ground, so that thelower surface of the canopy received approximately 13% of thelight incident on the upper surface. The light flux incidenton the sides of these canopies (c. 2m tall and 6m x 16m in area)amounted to some 20–30% of that incident on the uppersurface. About 32% of daylight falling on the glasshouse (c.9m x 18m in area) was intercepted by the glasshouse structureand glazing; of the 68% entering the house, some fell on headlandsoccupying 35% of the glasshouse area. The loss of light to headlands,and the gain from canopy side-lighting, would be relativelysmaller for larger glasshouses. At near-ambient CO₂ concentrations, net photosynthetic ratesof the cucumber canopy were comparable to those of closed canopiesof other glasshouse and field crops which have maximum lightconversion efficiencies of 5–8µg CO₂ J^–1 at50–200 W m^–2 incident light flux density. Efficiencydecreases only slightly with stronger light. Glasshouse cropswith CO₂ enrichment to 1200 vpm achieve conversion efficienciesof 7–10µg CO₂ J^–1. Efficiencies of utilizationof intercepted light, on an energy basis, reach 6–10%in various field and glasshouse crops with near-ambient CO₂,and reached an exceptional 11% for the cucumber canopy. Glasshousecrops with CO₂ enrichment achieve maximum efficiency of lightenergy utilization between 12% and 13%. Key words: Glasshouse cucumber and tomato, light interception and utilization, photosynthetic efficiency, row crops     

Morphological profiling using machine learning reveals emergent subpopulations of interferon-γ–stimulated mesenchymal stromal cells that predict immunosuppression

Background

Although a preponderance of pre-clinical data demonstrates the immunosuppressive potential of mesenchymal stromal cells (MSCs), significant heterogeneity and lack of critical quality attributes (CQAs) based on immunosuppressive capacity likely have contributed to inconsistent clinical outcomes. This heterogeneity exists not only between MSC lots derived from different donors, tissues and manufacturing conditions, but also within a given MSC lot in the form of functional subpopulations. We therefore explored the potential of functionally relevant morphological profiling (FRMP) to identify morphological subpopulations predictive of the immunosuppressive capacity of MSCs derived from multiple donors, manufacturers and passages.