The uses and abuses of Elinor Ostrom’s concept of commons in urban theorizing

Any urban setting will contain privately owned spaces, public space and different aspects of mixed space that are not wholly public or private but which constitute common resources. Some urban common resources are tangible such as parks, sidewalks and libraries and some are intangible like a sense of security allowing people to move freely in the city, a sense of belonging, or general buzz. The notion of commons has been given an important upswing in popularity after Elinor Ostrom’s 2009 Nobel Prize. Her work on common-pool resources seems to provide a starting point for grappling with issues of urban commons. However, Ostrom’s earlier work (Ostrom 1990) deals with subtractive and tangible resources (like fish, water and forests). And one important design principle for governance of these commons is that the group of appropriators can erect clear boundary rules. A central characteristic of urban settings however is mobility, permeable boundaries and perhaps that at least occasionally resources are less clearly subtractible. It is therefore questionable to what extent theories of governing the commons relying on Ostrom’s models can be applied in urban settings. However, it may also be that urban commons may have somewhat different character but may be fruitfully approached using the same basic framework. Inroads have been made for instance on informational commons (Ostrom 2007) which also seem radically different from fisheries or water basins. This paper presents are review (in process) of how Ostrom's theories have been applied in urban studies and to highlight the potential and limitations of these approaches

ISPTM: An Iterative Search Algorithm for Systematic Identification of Post-translational Modifications from Complex Proteome Mixtures

Identifying protein post-translational modifications (PTMs) from tandem mass spectrometry data of complex proteome mixtures is a highly challenging task. Here we present a new strategy, named iterative search for identifying PTMs (ISPTM), for tackling this challenge. The ISPTM approach consists of a basic search with no variable modification, followed by iterative searches of many PTMs using a small number of them (usually two) in each search. The performance of the ISPTM approach was evaluated on mixtures of 70 synthetic peptides with known modifications, on an 18-protein standard mixture with unknown modifications and on real, complex biological samples of mouse nuclear matrix proteins with unknown modifications. ISPTM revealed that many chemical PTMs were introduced by urea and iodoacetamide during sample preparation and many biological PTMs, including dimethylation of arginine and lysine, were significantly activated by Adriamycin treatment in nuclear matrix associated proteins. ISPTM increased the MS/MS spectral identification rate substantially, displayed significantly better sensitivity for systematic PTM identification compared with that of the conventional all-in-one search approach, and offered PTM identification results that were complementary to InsPecT and MODa, both of which are established PTM identification algorithms. In summary, ISPTM is a new and powerful tool for unbiased identification of many different PTMs with high confidence from complex proteome mixtures