We report on a minimal system to mimic intracellular transport of membrane-bounded, vesicular cargo. In a cell-free assay, purified kinesin-1 motor proteins were directly anchored to the membrane of giant unilamellar vesicles, and their movement studied along two-dimensional microtubule networks. Motion-tracking of vesicles with diameters of 1-3 μm revealed traveling distances up to the millimeter range. The transport velocities were identical to velocities of cargo-free motors. Using total internal reflection fluorescence (TIRF) microscopy, we were able to estimate the number of GFP-labeled motors involved in the transport of a single vesicle. We found that the vesicles were transported by the cooperative activity of typically 5-10 motor molecules. The presented assay is expected to open up further applications in the field of synthetic biology, aiming at the in vitro reconstitution of sub-cellular multi-motor transport systems. It may also find applications in bionanotechnology, where the controlled long-range transport of artificial cargo is a promising means to advance current lab-on-a-chip systems.
The paper focuses on processes of normalization through which dis/ability is simultaneously produced in specific collectives, networks, and socio-technological systems that enable the construction of such demarcations. Our point of departure is the cochlear implant (CI), a neuroprosthetic device intended to replace and/or augment the function of the damaged inner ear. Unlike hearing aids, which amplify sounds, the CI does the work of damaged hair cells in the inner ear by providing sound signals to the brain. We examine the processes of the CI's genesis as well as its specific uses by and interrelations to the different and divergent actors that the CI assembles. We argue that the technological device and the implicated normalization process mobilize complex effects in varying socio-technical arrangements. The CI is conceived as a Bboundary object^[89] or a Bquasi-object^[49, 83], i.e., a metastabilized medium of translation that coordinates social, cultural, and technological (inter)action. Although intended to transform non-hearing or hard of hearing people into competent and Bnormal^hearing subjects, the CI system reproduces the asymmetrical structures of the disability discourse [14] through its function of Bdeveloping and maintaining coherence between intersecting social worlds^ [89, 393]. Additionally, it initiates controversial discourses that have resulted in new forms of biosocial collectivities ranging from cochlear implantees with (restored) normal human hearing to (trans)human configurations who have passed through (post)human enhancement. Our approach is thus situated at the intersection of disability and media studies and tackles the particular conditions technological media configurations impose upon the (re-)production of dis/ability.
Against the backdrop of an aging world population increasingly affected by a diverse range of abilities and disabilities as well as the rise of ubiquitous computing and digital app cultures, this paper questions how mobile technologies mediate between heterogeneous environments and sensing beings. To approach the current technological manufacturing of the senses, two lines of thought are of importance: First, there is a need to critically reflect upon the concept of assistive technologies (AT) as artifacts providing tangible solutions for a specific disability. Second, the conventional distinction between user and environment requires a differentiated consideration. This contribution will first review James Gibson’s concept of “affordances” and modify this approach by introducing theories and methods of Science and Technology Studies (STS) and Actor-Network Theory (ANT). Then, we present two case studies where we explore the relations between recent “assistive” app technologies and human sensory perception. As hearing and seeing are key in this regard, we concentrate on two specific media technologies: ReSound LINX2, a hearing aid which allows for direct connect (via Bluetooth) with iPhone, iPad, or iPod Touch, and Camassia, an IOS app for sonic wayfinding for blind people. We emphasize the significance of dis-/abling practices for manufacturing novel forms of hearing and seeing and drawing on sources like promotional materials by manufacturers, ads, or user testimonials and reviews. Our analysis is interested in the reciprocal relationships between users and their socio-technical and media environments. By and large, this contribution will provide crucial insights into the contemporary entanglement of algorithm-driven technologies, daily practices, and sensing subjects: the production of techno-sensory arrangements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.