The role of nature's contributions to people in sustaining international trade of agricultural products

Nature's contributions to people (NCP) are essential for the production and trade of agricultural, forestry and fishery commodities. Often, there is a spatial disconnect between consumers and the natural systems where the commodities are produced. Traded agricultural products are therefore dependent on nature and NCP in their region of origin. The dependencies of agricultural products on NCP are, however, insufficiently recognised by consumers and are rarely considered in global environmental governance and trade policies along value chains. Here, we synthesise studies highlighting dependencies of agricultural products on NCP in their origin locations to identify opportunities and challenges in quantifying their contribution in sustaining trade flows. We suggest three methodological steps for quantifying NCP dependencies in international agricultural trade: spatial mapping of NCP supply and demand, linking NCP to agricultural trade flows, and tracing trade flows. Each methodological step requires further development and harmonisation to enable a complete accounting of how international agricultural trade depends on NCP. Given the lack of knowledge and data on how NCP support agricultural trade, social and environmental trade-offs of natural resource management are currently hard to quantify. Quantifying the role of NCP dependencies of traded agricultural products can support their sustainable management, contribute to supply chain accountability and serve as input to sustainable natural resource governance and foster responsibility and equity in supply chains. Read the free Plain Language Summary for this article on the Journal blog.</p

Quantum modeling of semiconductor gain materials and vertical-external-cavity surface-emitting laser systems

This article gives an,overview of the microscopic theory,theory used to quantitatively model a wide range of semiconductor laser gain materials. As a snapshot of the current state of research, applications to a variety of actual quantum-well systems are presented. Detailed theory experiment comparisons are shown and it is analyze how the theory can be used to extract poorly known material parameters. The intrinsic laser loss processes due to radiative and nonradiative Auger recombination are evaluated microscopically. The results are used for realistic simulations of vertical-external-cavity surface-emitting laser systems. To account for nonequilibrium effects, a simplified model is presented using pre-computed microscopic scattering and dephasing rates. Prominent deviations from quasi-equilibrium carrier distributions are obtained under strong in-well pumping conditions

Multiscale Feature Analysis of Salivary Gland Branching Morphogenesis

Pattern formation in developing tissues involves dynamic spatio-temporal changes in cellular organization and subsequent evolution of functional adult structures. Branching morphogenesis is a developmental mechanism by which patterns are generated in many developing organs, which is controlled by underlying molecular pathways. Understanding the relationship between molecular signaling, cellular behavior and resulting morphological change requires quantification and categorization of the cellular behavior. In this study, tissue-level and cellular changes in developing salivary gland in response to disruption of ROCK-mediated signaling by are modeled by building cell-graphs to compute mathematical features capturing structural properties at multiple scales. These features were used to generate multiscale cell-graph signatures of untreated and ROCK signaling disrupted salivary gland organ explants. From confocal images of mouse submandibular salivary gland organ explants in which epithelial and mesenchymal nuclei were marked, a multiscale feature set capturing global structural properties, local structural properties, spectral, and morphological properties of the tissues was derived. Six feature selection algorithms and multiway modeling of the data was performed to identify distinct subsets of cell graph features that can uniquely classify and differentiate between different cell populations. Multiscale cell-graph analysis was most effective in classification of the tissue state. Cellular and tissue organization, as defined by a multiscale subset of cell-graph features, are both quantitatively distinct in epithelial and mesenchymal cell types both in the presence and absence of ROCK inhibitors. Whereas tensor analysis demonstrate that epithelial tissue was affected the most by inhibition of ROCK signaling, significant multiscale changes in mesenchymal tissue organization were identified with this analysis that were not identified in previous biological studies. We here show how to define and calculate a multiscale feature set as an effective computational approach to identify and quantify changes at multiple biological scales and to distinguish between different states in developing tissues