14,749 research outputs found

    Polar relaxation by dynein-mediated removal of cortical myosin II

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    Nearly 6 decades ago, Lewis Wolpert proposed the relaxation of the polar cell cortex by the radial arrays of astral microtubules as a mechanism for cleavage furrow induction (White and Borisy, 1983; Wolpert, 1960). While this mechanism has remained controversial (Rappaport, 1996), recent work has provided evidence for polar relaxation by astral microtubules (Chen et al., 2008; Dechant and Glotzer, 2003; Foe and Dassow, 2008; Murthy and Wadsworth, 2008; Werner et al., 2007), although its molecular mechanisms remain elusive. Here, using C. elegans embryos, we show that polar relaxation is achieved through dynein-mediated removal of myosin II from the polar cortexes. Mutants that position centrosomes closer to the polar cortex accelerated furrow induction whereas suppression of dynein activity delayed furrowing. We provide evidence that dynein-mediated removal of myosin II from the polar cortexes triggers cortical flow towards the cell equator, which induces the assembly of the actomyosin contractile ring. These studies for the first time provide a molecular basis for the aster-dependent polar relaxation, which works in parallel with equatorial stimulation to promote robust cytokinesis

    Colin Mochrie vs. Jesus H. Christ: Messages About Masculinities and Fame in Online Video Conversations

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    With the availability of relatively easy-to-use tools for online video creation and distribution, people are increasingly producing videos not just for artistic expression, but also as a form of communication. This article examines two types of online video conversations, one within a specific online subculture, and one a series of responses to one particularly wellknown video. Videos lend themselves to the expression of ambiguity, contradictory meanings, taboo topics, and emotions. Within these two video conversations, topics include discussions of masculinity, identity, and fame.published or submitted for publicationis peer reviewe

    Universities as Living Labs for sustainable development : a global perspective

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    Walter Leal Filho, Baltazar Andrade Guerra, Mark Mifsud and Rudi Pretorius use case studies from Brazil, Malta and South Africa to reflect on how the Living Labs approach can contribute towards a more sustainable futurepeer-reviewe

    From Personal Memories to Sharable Memories

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    The exchange of personal experiences is a way of supporting decision making and interpersonal communication. In this article, we discuss how augmented personal memories could be exploited in order to support such a sharing. We start with a brief summary of a system implementing an augmented memory for a single user. Then, we exploit results from interviews to define an example scenario involving sharable memories. This scenario serves as background for a discussion of various questions related to sharing memories and potential approaches to their solution. We especially focus on the selection of relevant experiences and sharing partners, sharing methods, and the configuration of those sharing methods by means of reflection
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