Abrupt transition of mesic grassland to shrubland: evidence for thresholds, alternative attractors, and regime shifts

Ecology ◽  
2014 ◽  
Vol 95 (9) ◽  
pp. 2633-2645 ◽  
Author(s):  
Zak Ratajczak ◽  
Jesse B. Nippert ◽  
Troy W. Ocheltree
Author(s):  
R.A Walker ◽  
S. Inoue ◽  
E.D. Salmon

Microtubules polymerized in vitro from tubulin purified free of microtubule-associated proteins exhibit dynamic instability (1,2,3). Free microtubule ends exist in persistent phases of elongation or rapid shortening with infrequent, but, abrupt transitions between these phases. The abrupt transition from elongation to rapid shortening is termed catastrophe and the abrupt transition from rapid shortening to elongation is termed rescue. A microtubule is an asymmetrical structure. The plus end grows faster than the minus end. The frequency of catastrophe of the plus end is somewhat greater than the minus end, while the frequency of rescue of the plus end in much lower than for the minus end (4).The mechanism of catastrophe is controversial, but for both the plus and minus microtubule ends, catastrophe is thought to be dependent on GTP hydrolysis. Microtubule elongation occurs by the association of tubulin-GTP subunits to the growing end. Sometime after incorporation into an elongating microtubule end, the GTP is hydrolyzed to GDP, yielding a core of tubulin-GDP capped by tubulin-GTP (“GTP-cap”).


Somatechnics ◽  
2013 ◽  
Vol 3 (1) ◽  
pp. 9-30
Author(s):  
Fiona K. O'Neill

In the UK, when one is suspected of having breast cancer there is usually a rapid transition from being diagnosed, to being told you require treatment, to this being effected. Hence, there is a sense of an abrupt transition from ‘normal’ embodiment through somatechnic engagement; from normality, to failure and otherness. The return journey to ‘embodied normality’, if indeed there can be one, is the focus of this paper; specifically the durée and trajectory of such normalisation. I offer a personal narrative from encountering these ‘normalising interventions’, supported by the narratives of other ‘breast cancer survivors’. Indeed, I havechosento become acquainted with my altered/novel embodiment, rather than the symmetrisation of prosthetication, to ‘wear my scars’,and thus subvert the trajectory of mastectomy. I broach and brook various encounters with failure by having, being and doing a body otherwise; exploring, mastering and re-capacitating my embodiment, finding the virtuosity of failure and subversion. To challenge the durée of ‘normalisation’ I have engaged in somatic movement practices which allow actual capacities of embodiment to be realised; thorough kinaesthetic praxis and expression. This paper asks is it soma, psyche or techné that has failed me, or have I failed them? What mimetic chimera ‘should’ I become? What choices do we have in the face of failure? What subversions can be allowed? How subtle must one be? What referent shall I choose? What might one assimilate? Will mimesis get me in the end? What capacities can one find? How shall I belong? Where / wear is my fidelity? The hope here is to address the intra-personal phenomenological character and the inter-corporeal socio-ethico-political aspects that this body of failure engenders, as one amongst many.


2012 ◽  
Author(s):  
Ivelina Pavlova ◽  
Ann Marie Hibbert ◽  
Joel R. Barber ◽  
Krishnan Dandapani

Ecology ◽  
2012 ◽  
Vol 93 (3) ◽  
pp. 619-631 ◽  
Author(s):  
Motomi Genkai-Kato ◽  
Yvonne Vadeboncoeur ◽  
Lone Liboriussen ◽  
Erik Jeppesen

1996 ◽  
Vol 78 (1) ◽  
pp. 111 ◽  
Author(s):  
Rene Garcia ◽  
Pierre Perron

2012 ◽  
Vol 5 (4) ◽  
pp. 591-604 ◽  
Author(s):  
Golan Bel ◽  
Aric Hagberg ◽  
Ehud Meron

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