Pedro, It is amazing to see Figure 6 (Prototypical signaling pathways of multicellularity) and imagine the academic path that led to this product. It is (no doubt) a result of interdisciplinary work between engineering, Biology and Information Science.
Pedro can you send the reference of this image? Kind regards Moisés. 2016-04-28 9:49 GMT-03:00 Pedro C. Marijuan <pcmarijuan.i...@aragon.es>: > Dear Alex and colleagues, > > Thanks for the opportunity to ad a few lines on signaling matters. I would > not discard any organizational aspect of signaling pathways. I have put > below a diagram that approaches the dynamics of some major ones.Your > analogy with mobile phones would be right, provided that conversations were > mixed, that a number of receivers were just random, and that a component of > "experience information" would be entered too --I think it can apply to the > dynamics of second messengers, where multitudes of microevents and pathways > may be integrated via lots of feedbacks (See the box in the figure below). > Symmetry is a big word concerning the organization of pathways in the > construction of multicellular development... opposed paths, tipping points, > collective (populational) symmetry breakings, massive feedbacks, etc. > > By the way, when we commented days ago on Tononi's phi, both from John > Collier and myself, the idea was to consider it as applied to the closure > of meaning episodes in language. How "getting" the meaning of some > linguistic episode (eg, a joke) provokes a sudden change of transient > connectivity between areas... > > Apart from meaning, it may also be interesting that there seems to be a > strong asymmetry in between the incoming / outgoing information flows--the > "social info loops" around. In most human organizations, the ratio is in > between 3 and 4. It means that you and me are ordered by upper levels in > around 80 % of our exchanges, while what we send upwards becomes a meager > 20 %. It is from a statistics on business communication metrics. The > generalization is far from direct, but maybe it would occur in the cells > too--amazingly there is very little literature on cellular "signal > emission". > > Anyhow, how the whole ascending and descending info flows give raise to > all the varieties of organizational complexity is a fascinating problem, > > All the best--Pedro > > > > > > > > *Figure 6: Prototypical signaling pathways of multicellularity.* From > left to right, a stimulus in the intercellular space binds to a > transmembrane receptor (sensor) on its extracellular domain. Upon binding, > the receptor undergoes a transient modification of its cytoplasmic domain; > this effect triggers a transient modification of a series of proteins in > the cell, each one acting as an intermediate in the signal transduction > pathway (signal processing), with characteristic hierarchies of protein > kinases and second messengers. The last components are actuators or > effectors that activate or inhibit proteins and channels that control > several cellular functions, notably gene expression by means of > transcriptional switches that may interact with several coactivator > partners. The whole biochemical changes produced in the cell represent the > response to the received signal —its *molecular meaning*. > > > > El 26/04/2016 a las 10:10, Alex Hankey escribió: > > Dear Pedro, > > Thank you for the comments on my presentation, and particularly for > reminding us all that life transmits information of many different kinds by > very specific and selective processes in chemical signally molecules. > > I must confess that I had assumed that such kinds of signals could be > considered special cases of digital information analogous to the codes > transmitted by a digital signalling tower in a mobile telephone network, > where the initial code has to name the device that the rest of that message > section is meant to receive. > > In mobile phone systems, individual devices are sent information by > identifiers. If we have a nervous system working with several > neurotransmitters, or a cell signalling system working with a number of > cytokines, each with a specific regulatory influence / purpose, are these > individual items not performing in ways that are covered by the usual > combination of Wiener and Shannon, and therefore in principle understood, > and AS YOU SPECIFICALLY POINT OUT, with no particular "experience" > component. > > I wonder whether the material I transmitted made the following point > succinctly / precisely enough: > David Chalmers specifically hypothesized that 'experience information' (my > terminology) mst have a double aspect, and that the 'loop' arising from > criticality specifically fulfils his hypothesis in a new and potent way. > (The material contains so many points that this, to my mind, really > significant one may have got buried.) > > Thank you also for appreciating the amplification of Tononi's contribution > (Tononi, I personally regard as of real significance). The internal loop > creates > the internal coherence that is required to form the 'integrated > information'. > > I have a suspicion that the following propositions are probably correct: > a. any information structure that is truly 'non-reductive' > (Chalmers requirement 3) must possess long range coherence. > b. any information structure with long-range coherence will be a form of > integrated information. > c. Hence Chalmers requirement 3 in fact specifies integrative information. > This sequence a, b, c simplifies what those writing in the 1990's were > saying: > they were in fact setting equivalent requirements on the form of > 'experience information' > (though Tononi undoubtedly thought he was saying something different, as > did those who followed up on his work, and Chalmers did not realize that > Tononi's proposal was equivaent to the point that he had proposed. > > Anyone's thoughts on this would be very much appreciated, > All best wishes, > > Alex > > -- > ------------------------------------------------- > Pedro C. Marijuán > Grupo de Bioinformación / Bioinformation Group > Instituto Aragonés de Ciencias de la Salud > Centro de Investigación Biomédica de Aragón (CIBA) > Avda. San Juan Bosco, 13, planta X > 50009 Zaragoza, Spain > Tfno. +34 976 71 3526 (& > 6818)pcmarijuan.iacs@aragon.eshttp://sites.google.com/site/pedrocmarijuan/ > ------------------------------------------------- > > > _______________________________________________ > Fis mailing list > Fis@listas.unizar.es > http://listas.unizar.es/cgi-bin/mailman/listinfo/fis > > -- Moisés André Nisenbaum Doutorando IBICT/UFRJ. Professor. Msc. Instituto Federal do Rio de Janeiro - IFRJ Campus Rio de Janeiro moises.nisenb...@ifrj.edu.br
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