Wireless Play and Unexpected Innovation

Part of the Volume on Digital Young, Innovation, and the Unexpected. This chapter considers play as leading to unexpected innovation in advanced wireless technologies. It concludes that much of the potential for new media to enhance innovation actually echoes much older patterns, as evidenced by comparisons to wireless history. These are patterns of privilege, particularly class and gender privilege, reinforced by strict intellectual property protections. Detailed case studies are presented of the "wardrivers," young male computer enthusiasts who helped map wi-fi signals over the past decade, and of earlier analog wireless enthusiasts. The chapter offers a solid critique of many present-day celebrations of technology-driven innovation and of the rhetoric of participatory culture

Debunking Internet Myths: slow, centralised and local reality

The UK Government remains consistent in its commitment to roll out “superfast” broadband across the country. But what does superfast broadband mean and will having superfast broadband in the UK really give the increased in capacity and access to global content that it should. A July report from Ofcom on internet speeds and research presented at the Annenberg/Oxford Media Policy Summer Institute paint a surprising picture of what speed consumers really get and the other limits to online capacity and access. It turns out that the network we rely on is often much slower than advertised and extremely centralised, despite the common mantra of a global and widespread infrastructure

Infrastructure studies meet platform studies in the age of Google and Facebook

Two theoretical approaches have recently emerged to characterize new digital objects of study in the media landscape: infrastructure studies and platform studies. Despite their separate origins and different features, we demonstrate in this article how the cross-articulation of these two perspectives improves our understanding of current digital media. We use case studies of the Open Web, Facebook, and Google to demonstrate that infrastructure studies provides a valuable approach to the evolution of shared, widely accessible systems and services of the type often provided or regulated by governments in the public interest. On the other hand, platform studies captures how communication and expression are both enabled and constrained by new digital systems and new media. In these environments, platform-based services acquire characteristics of infrastructure, while both new and existing infrastructures are built or reorganized on the logic of platforms. We conclude by underlining the potential of this combined framework for future case studies

Beyond mystery: Putting algorithmic accountability in context

Critical algorithm scholarship has demonstrated the difficulties of attributing accountability for the actions and effects of algorithmic systems. In this commentary, we argue that we cannot stop at denouncing the lack of accountability for algorithms and their effects but must engage the broader systems and distributed agencies that algorithmic systems exist within; including standards, regulations, technologies, and social relations. To this end, we explore accountability in “the Generated Detective,” an algorithmically generated comic. Taking up the mantle of detectives ourselves, we investigate accountability in relation to this piece of experimental fiction. We problematize efforts to effect accountability through transparency by undertaking a simple operation: asking for permission to re-publish a set of the algorithmically selected and modified words and images which make the frames of the comic. Recounting this process, we demonstrate slippage between the “complication” of the algorithm and the obscurity of the legal and institutional structures in which it exists

The secretion inhibitor Exo2 perturbs trafficking of Shiga toxin between endosomes and the trans-Golgi network

The small-molecule inhibitor Exo2 {4-hydroxy-3-methoxy-(5,6,7,8-tetrahydrol[1]benzothieno[2,3-d]pyrimidin-4-yl)hydraz-one benzaldehyde} has been reported to disrupt the Golgi apparatus completely and to stimulate Golgi–ER (endoplasmic reticulum) fusion in mammalian cells, akin to the well-characterized fungal toxin BFA (brefeldin A). It has also been reported that Exo2 does not affect the integrity of the TGN (trans-Golgi network), or the direct retrograde trafficking of the glycolipid-binding cholera toxin from the TGN to the ER lumen. We have examined the effects of BFA and Exo2, and found that both compounds are indistinguishable in their inhibition of anterograde transport and that both reagents significantly disrupt the morphology of the TGN in HeLa and in BS-C-1 cells. However, Exo2, unlike BFA, does not induce tubulation and merging of the TGN and endosomal compartments. Furthermore, and in contrast with its effects on cholera toxin, Exo2 significantly perturbs the delivery of Shiga toxin to the ER. Together, these results suggest that the likely target(s) of Exo2 operate at the level of the TGN, the Golgi and a subset of early endosomes, and thus Exo2 provides a more selective tool than BFA for examining membrane trafficking in mammalian cells

Membrane fusion mediated by ricin and viscumin

AbstractThe ribosome inactivating plant proteins (RIPs) ricin and viscumin but not Ricinus communis agglutinin are able induce vesicle–vesicle fusion. A model is suggested in which the toxicity of the RIPs is partially determined by their fusogenicity. Herein, fusion is hypothesized to allow the RIPs to leak across endocytic vesicles to approve their access to cytoplasmic ribosomes

The proteasome cap RPT5/Rpt5p subunit prevents aggregation of unfolded ricin A chain

The plant cytotoxin ricin enters mammalian cells by receptor-mediated endocytosis, undergoing retrograde transport to the endoplasmic reticulum (ER) where its catalytic A chain (RTA) is reductively separated from the holotoxin to enter the cytosol and inactivate ribosomes. The currently accepted model is that the bulk of ER-dislocated RTA is degraded by proteasomes. We show here that the proteasome has a more complex role in ricin intoxication than previously recognised, that the previously reported increase in sensitivity of mammalian cells to ricin in the presence of proteasome inhibitors simply reflects toxicity of the inhibitors themselves, and that RTA is a very poor substrate for proteasomal degradation. Denatured RTA and casein compete for a binding site on the regulatory particle of the 26S proteasome, but their fates differ. Casein is degraded, but the mammalian 26S proteasome AAA-ATPase subunit RPT5 acts as a chaperone that prevents aggregation of denatured RTA and stimulates recovery of catalytic RTA activity in vitro. Furthermore, in vivo, the ATPase activity of Rpt5p is required for maximal toxicity of RTA dislocated from the Saccharomyces cerevisiae ER. Our results implicate RPT5/Rpt5p in the triage of substrates in which either activation (folding) or inactivation (degradation) pathways may be initiated

Spectrum Miscreants, Vigilantes, and Kangaroo Courts: The Return of the Wireless Wars

Symposium: Rough Consensus and Running Code: Integrating Engineering Principles into Internet Policy Debates, held at the University of Pennsylvania\u27s Center for Technology Innovation and Competition on May 6-7, 2010. It is axiomatic that government licensing is a foundational requirement for the use of the electromagnetic spectrum. Yet in some bands there is no licensing requirement, providing an empirical site that can be used to examine wireless coexistence without licenses. This Article draws on ethnographic work with wireless Internet Service Providers to report on the extralegal means that are used to share or allocate spectrum in these license exempt bands. Operators use a variety of informal arrangements there, including jamming and extortion. It concludes that wireless may be increasingly subject to extralegal allocation, and the outcomes of federal spectrum policy may in fact rest in local hands

The role of olfactory ensheathing cells, MRI, and biomaterials in transplant-mediated CNS repair

Bruk av olfaktoriske ensheathing celler, MRI og biomaterialer i transplantasjonsmediert reparasjon av CNS skader Den beskrevne studien har brukt en interdisiplinær tilnærming for å evaluere transplantasjons mediert CNS reparasjon i en skademodell av synsnerven. Ved å integrere forskjellige MRI metoder har vi analysert olfaktoriske ensheathing celler’s (OEC) evne til å integrere og overleve in vivo i vår skademodell. Cellenes evne til å modulere regenerasjonen av den skadede synsnerven er også dokumentert ultrastrukturelt med elektronmikroskopi (EM). Studien har også omfattet in vitro analyser av interaksjonen mellom OEC og modifiserte biopolymerer i 2-og 3-dimensjonale matriser. Den spesifikke målsetningen med denne studien har vært: (a) Utvikle protokoller for effektiv merkning av OEC med mikron store jern partikler; (b) Kombinere cellulær MRI og mangan-forsterket MRI (MEMRI) for spatiotemporal monitorering av intravitreal (ivit) og intra-optisk nerve (iON) transplantasjon av OEC; (c) Studere celleimplantatenes evne til å promotere regenerasjon av synsbane aksoner etter skade i synsnerven både (i) longitudinelt in vivo med MRI og (ii) ultrastrukturelt med transmisjons elektron mikroskopi (TEM); (d) Produsere og teste modifiserte alginat strukturer som plattformer for kontrollert frigjøring av mangan (Mn2+) brukt som kontrastmiddel ved MEMRI; (e) Utvikle arginin-glycin-aspartat (RGD)-peptid alginater og karakterisere interaksjonen med OEC dyrket på disse modifiserte aliginat matrisene. I avhandlingen presenteres gjennomføringen av disse målene og belyser potensialet av å integrere MRI, biomateraler og celleterapeutiske teknologier i studier av transplantasjons-mediert reparasjon av skader i CNS.PhD i Nevrovitenskap / Neuroscience (tverrfakultært)PhD in Neuroscienc