1,721,039 research outputs found
A third transition in science?
Full text linkSince Newton, classical and quantum physics depend upon the "Newtonian Paradigm". The relevant variables of the system are identified. For example, we identify the position and momentum of classical particles. Laws of motion in differential form connecting the variables are formulated. An example is Newton's three Laws of Motion. The boundary conditions creating the phase space of all possible values of the variables are defined. Then, given any initial condition, the differential equations of motion are integrated to yield an entailed trajectory in the pre-stated phase space. It is fundamental to the Newtonian Paradigm that the set of possibilities that constitute the phase space is always definable and fixed ahead of time.
This fails for the diachronic evolution of ever-new adaptations in any biosphere. Living cells achieve Constraint Closure and construct themselves. Thus, living cells, evolving via heritable variation and Natural selection, adaptively construct new-in-the-universe possibilities. We can neither define nor deduce the evolving phase space: We can use no mathematics based on Set Theory to do so. We cannot write or solve differential equations for the diachronic evolution of ever-new adaptations in a biosphere.
Evolving biospheres are outside the Newtonian Paradigm. There can be no Theory of Everything that entails all that comes to exist.
We face a third major transition in science beyond the Pythagorean dream that ``All is Number'' echoed by Newtonian physics.
However, we begin to understand the emergent creativity of an evolving biosphere: Emergence is not engineering
On the fate of perturbations in critical random Boolean networks
No full textAbstract Random Boolean models of genetic regulatory networks, when subject tosmall noise, may either forget past distinctions or yield divergence in state space trajectoriesprecluding reliable action. With a specic choice of the model parameters, suchnetworks are in a critical regime and optimize capacity to bind past and future. Anin-depth study of the response to perturbation of critical random Boolean networks ishere presented. It is shown that networks built with critical values of the parametersmay, however, frequently show behaviours that are more typical of the ordered or of thedisordered regime. A further classication of critical networks is thus proposed withthe objective of isolating those networks that exhibit really critical dynamic
Timing of molecular processes in a synchronous Boolean model of genetic regulatory network
No full textA generalization of the model of random Boolean network (RBN) is presented, in whichthe concept of timing of regulatory processes is explicitly introduced, together with novel types ofentity and interaction, directly inspired to real genetic networks. Beyond the attempt ofapproaching a higher level of faithfulness to the natural world, at the base of the development ofthe model is the need for a sensible comparison with time-series microarray data-sets, inaccessibleto the original RBN model, because of the strict assumptions about the simultaneity of theregulation mechanisms. Preliminary analysis on networks typified by “critical” parameters showeda strong, even though not univocal, influence of a variation in the distribution of the time delaysthat characterize the entities of the system on the emerging dynamics: the larger the “memory” ofthe system about its dynamical evolution is, the more ordered the behaviour would tend to be
Information transfer among coupled Random Boolean Networks
No full textInformation processing and information flow occur at many levels in the course of an organism’s development and throughout its lifespan. Biological networks inside cells transmit information from their inputs (e.g. the concentrations of proteins or other signaling molecules) to their outputs (e.g. the expression levels of various genes). Moreover, cells do not exist in isolation, but they constantly interact with one another. We study the information flow in a model of interacting genetic networks, which are represented as Boolean graphs. It is observed that the information transfer among the networks is not linearly dependent on the amount of nodes that are able to influence the state of genes in surrounding cells
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Summary I- Modelling Genetic Networks using Boolean Networks
No full textRandom Boolean networks (RBN) were first used by Stuart. A. Kauffman [6] more than thirthy years ago as a tool for studying the dynamics of complex natura
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