[Re]Valuing Surplus: Transitions, technologies and tensions in redistributing prepared food in San Francisco

https://doi.org/10.1016/j.geoforum.2018.11.005Attention to value, exchange and circulation has long been a central feature of trade flow analyses. More recently, scholars have sought to extend these frames to examine the ongoing movements of end-of-life goods; essentially examining the waste mobilities of commodities. These flows have particular geographies and practices of valuing and revalorization depending on the material and relational qualities of the commodities in question. However, surprisingly little analysis has taken place of the movement of food surplus within these debates and even less has been conducted with respect to the movements of surplus prepared food. In response, this paper examines the particular value choreography of redistributing surplus prepared food in San Francisco. Four initiatives, which use information and communication technologies (ICT) to help put this particularly challenging form of food surplus to further use, are analysed. Specific attention is given to the transitions, technologies and tensions that shape the [re]valuing of surplus food in places and as it travels across space and time amongst diverse actors. In conclusion, it is argued that while commercial economic values and logics play a pivotal role in opening up particular types of food for redistribution, actual practices of moving food along are suffused with a much more complex and shifting architecture of values and valuers

Creative construction: Crafting, negotiating and performing urban food sharing landscapes.

Arbuscular mycorrhizal fungi arguably form the most successful and wide-spread endosymbiosis with plants. In general terms there is very little host-specificity in this interaction, indicating an extremely broad compatibility. However, host preferences as well as varying symbiotic efficiencies have been observed, the molecular basis of which is still largely unknown. Secreted proteins (SPs) may act as fungal effectors to control symbiotic efficiency in a host-dependent manner. Therefore, we studied whether AM fungi adjust their secretome in a host- and stage-dependent manner to contribute to their extremely wide host-range. We investigated the expression of SP encoding genes of R. irregularis DAOM197198 in three evolutionary distantly related plant species, Medicago truncatula (Medicago), Nicotiana benthamiana (Nicotiana) and Allium schoenoprasum (Chives). In addition we used laser microdissection in combination with RNAseq to study SP expression at different stages of the symbiotic interaction in Medicago. Our data indicate that the vast majority of 288 expressed SPs show equal expression levels in the interaction with all three host plants. In addition, a subset (~15%) of the SPs show significant differential expression depending on the host plant and/or environmental condition. This host-dependent expression appears to be controlled locally in the hyphal network in response to host metabolic cues. Overall, this study offers a comprehensive analysis of the R. irregularis secretome, which now offers a solid basis to direct functional studies on the role of fungal SPs in AM symbiosis