Formal Definitions of Unbounded Evolution and Innovation Reveal Universal Mechanisms for Open-Ended Evolution in Dynamical Systems

Open-ended evolution (OEE) is relevant to a variety of biological, artificial and technological systems, but has been challenging to reproduce in silico. Most theoretical efforts focus on key aspects of open-ended evolution as it appears in biology. We recast the problem as a more general one in dynamical systems theory, providing simple criteria for open-ended evolution based on two hallmark features: unbounded evolution and innovation. We define unbounded evolution as patterns that are non-repeating within the expected Poincare recurrence time of an equivalent isolated system, and innovation as trajectories not observed in isolated systems. As a case study, we implement novel variants of cellular automata (CA) in which the update rules are allowed to vary with time in three alternative ways. Each is capable of generating conditions for open-ended evolution, but vary in their ability to do so. We find that state-dependent dynamics, widely regarded as a hallmark of life, statistically out-performs other candidate mechanisms, and is the only mechanism to produce open-ended evolution in a scalable manner, essential to the notion of ongoing evolution. This analysis suggests a new framework for unifying mechanisms for generating OEE with features distinctive to life and its artifacts, with broad applicability to biological and artificial systems.Comment: Main document: 17 pages, Supplement: 21 pages Presented at OEE2: The Second Workshop on Open-Ended Evolution, 15th International Conference on the Synthesis and Simulation of Living Systems (ALIFE XV), Canc\'un, Mexico, 4-8 July 2016 (http://www.tim-taylor.com/oee2/

Improving Accessibility of Public Transport Information for the Blind

Information that sighted commuters take for granted in Copenhagens public transportation network is often inaccessible to people who are blind or partially sighted. We identified potential improvements to the accessibility of transit information to recommend to the Danish Association of the Blind. We determined the main challenges blind and partially sighted people face when accessing transit information; observed the current accessibility of the system; and evaluated accessible solutions to identify the best potential improvements. Based on our findings, we recommend expanded use of audio announcements, stricter regulation for bus operators, increasing the accessibility of mobile phone applications, and the implementation of beacon technology in the bus system

Design of a Standardized in vitro Model of Skeletal Muscle Regeneration For Implantable Fibrin Microthread Scaffolds

Current treatments for Volumetric Muscle Loss (VML) defects limit the restoration of functional muscle tissue at the site of the wound, where the primary action and uniaxial growth of the myoblasts is destroyed. Wounded warriors and trauma patients undergo months of painful and expensive treatments for VML, with limited outcomes. Implantable biomimetic scaffolds are being explored as treatments for VML injuries because of their ability to guide uniaxial regeneration of muscle tissue. In this project, we created a reproducible, user friendly, and cost effective 3D model to depict skeletal muscle outgrowth onto fibrin microthreads in vitro, mimicking wound healing responses to the scaffold in vivo

Cytokinin response factor 6 represses cytokinin-associated genes during oxidative stress

Cytokinin is a phytohormone that is well known for its roles in numerous plant growth and developmental processes, yet it has also been linked to abiotic stress response in a less defined manner. Arabidopsis (Arabidopsis thaliana) Cytokinin Response Factor 6 (CRF6) is a cytokinin-responsive AP2/ERF-family transcription factor that, through the cytokinin signaling pathway, plays a key role in the inhibition of dark-induced senescence. CRF6 expression is also induced by oxidative stress, and here we show a novel function for CRF6 in relation to oxidative stress and identify downstream transcriptional targets of CRF6 that are repressed in response to oxidative stress. Analysis of transcriptomic changes in wild-type and crf6 mutant plants treated with H2O2 identified CRF6-dependent differentially expressed transcripts, many of which were repressed rather than induced. Moreover, many repressed genes also show decreased expression in 35S:CRF6 overexpressing plants. Together, these findings suggest that CRF6 functions largely as a transcriptional repressor. Interestingly, among the H2O2 repressed CRF6-dependent transcripts was a set of five genes associated with cytokinin processes: (signaling) ARR6, ARR9, ARR11, (biosynthesis) LOG7, and (transport) ABCG14. We have examined mutants of these cytokinin-associated target genes to reveal novel connections to oxidative stress. Further examination of CRF6-DNA interactions indicated that CRF6 may regulate its targets both directly and indirectly. Together, this shows that CRF6 functions during oxidative stress as a negative regulator to control this cytokinin-associated module of CRF6-dependent genes and establishes a novel connection between cytokinin and oxidative stress response

Education and Decision Making at the Time of Triptan Prescribing: Patient Expectations vs Actual Practice

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106941/1/head12308.pd