3 research outputs found

    The Dam1 ring binds to the E-hook of tubulin and diffuses along the microtubule.

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    There has been much effort in recent years aimed at understanding the molecular mechanism by which the Dam1 kinetochore complex is able to couple microtubule depolymerization to poleward movement. Both a biased diffusion and a forced walk model have been proposed, and several key functional aspects of Dam1-microtubule binding are disputed. Here, we investigate the elements involved in tubulin-Dam1 complex interactions and directly visualize Dam1 rings on microtubules in order to infer their dynamic behavior on the microtubule lattice and its likely relevance at the kinetochore. We find that the Dam1 complex has a preference for native tubulin over tubulin that is lacking its acidic C-terminal tail. Statistical mechanical analysis of images of Dam1 rings on microtubules, applied to both the distance between rings and the tilt angle of the rings with respect to the microtubule axis, supports a diffusive ring model. We also present a cryo-EM reconstruction of the Dam1 ring, likely the relevant assembly form of the complex for energy coupling during microtubule depolymerization in budding yeast. The present studies constitute a significant step forward by linking structural and biochemical observations toward a comprehensive understanding of the Dam1 complex

    Isn’t it time to change the way we think about time?

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    We live in a world where everyday objects, digital services, and human beings are increasingly interconnected. This forum aims to offer and promote a rich discussion on the challenges of designing for a broader ecology of materials, artifacts, and practices. --- Elisa Giaccardi, Editor </jats:p

    Transitions in Human Computer Interaction: From Data Embodiment to Experience Capitalism

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    This article develops a critical theory of human–computer interaction (critical HCI) intended to test some of the assumptions and omissions made in the field as it transitions from a cognitive theoretical frame to a phenomenological understanding of user experience described by Harrison et al. (the three paradigms of HCI. Paper presented at the Conference on human factors in computing systems. https://people.cs.vt.edu/~srh/Downloads/TheThreeParadigmsofHCI.pdf, 2007) as a third research paradigm and similarly Bødker (when second wave HCI meets third-wave challenges. In: NordiCHI ‘06 Proceedings of the 4th Nordic conference on human–computer interaction: changing roles, 1–8. http://dl.acm.org/citation.cfm?id=1182476; 2006, Interactions 22(5):24–31; Bødker, Interactions 22(5)):24–31, 2015) as third-wave HCI. Although this particular focus on experience has provided some novel avenues of academic enquiry, this article draws attention to a distinct bridge between the conventional HCI disciplinary concerns with predominantly task-based digital work and use context and a growing business interest in consumer experiences in digital environments. Critical HCI addresses the problem of experience in two interrelated ways. On one hand, it explores the role market logic plays in putting user experiences to work. On the other hand, it engages with ontological understandings of experience hitherto realized in HCI by way of a phenomenological matrix (Harrison et al. The three paradigms of HCI. Paper presented at the Conference on human factors in computing systems. https://people.cs.vt.edu/~srh/Downloads/TheThreeParadigmsofHCI.pdf, 2007). The article concludes by bringing in an old thinker (A. N. Whitehead) to consider experience in novel ways that relate ontological concerns to a broader political concept of experience capitalism
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