407 research outputs found

    Idea representation and elaboration in design inspiration and fixation experiments

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    Design fixation experiments often report that participants exposed to an example solution generate fewer ideas than those who were not. This reduced ‘idea fluency’ is generally explained as participants’ creativity being constrained by the example they have seen. However, the inclusion of an example also introduces other factors that might affect idea fluency in the experiments. We here offer an additional explanation for these results: participants not exposed to the example tend to generate ideas with little elaboration, while the level of detail in the example encourages a similar level of elaboration among stimulated participants. Because idea elaboration is time consuming, non-stimulated participants record more ideas overall. We investigated this hypothesis by reanalyzing data from three different studies; in two of them we found that non-stimulated participants generated more ideas and more ideas containing only text, whilst stimulated participants generated ideas that were more elaborated. Based on the creativity literature, we provide several explanations for the differences in results found across studies. Our findings and explanations have implications for the interpretation of creativity experiments reported to date and for the design of future studies.The CAPES Foundation, Ministry of Education of Brazil (BEX11468/13-0); The UK’s Engineering and Physical Sciences Research Council (EP/K008196/1

    Lessons and perspectives for applications of stochastic models in biological and cancer research

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    The effects of randomness, an unavoidable feature of intracellular environments, are observed at higher hierarchical levels of living matter organization, such as cells, tissues, and organisms. Additionally, the many compounds interacting as a well-orchestrated network of reactions increase the difficulties of assessing these systems using only experiments. This limitation indicates that elucidation of the dynamics of biological systems is a complex task that will benefit from the establishment of principles to help describe, categorize, and predict the behavior of these systems. The theoretical machinery already available, or ones to be discovered to help solve biological problems, might play an important role in these processes. Here, we demonstrate the application of theoretical tools by discussing some biological problems that we have approached mathematically: fluctuations in gene expression and cell proliferation in the context of loss of contact inhibition. We discuss the methods that have been employed to provide the reader with a biologically motivated phenomenological perspective of the use of theoretical methods. Finally, we end this review with a discussion of new research perspectives motivated by our results

    Policies to Regulate Distributed Data Exchange

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    This research is partially sponsored by the EPSRC grant EP/P011829/1, funded under the UK Engineering and Physical Sciences Council Human Dimensions of Cyber Security call (2016).Postprin

    Identification of a tyrosine residue responsible for N-acetylimidazole-induced increase of activity of ecto-nucleoside triphosphate diphosphohydrolase 3

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    Chemical modification in combination with site-directed mutagenesis was used to identify a tyrosine residue responsible for the increase in ecto-nucleoside triphosphate diphosphohydrolase 3 (NTPDase3) nucleotidase activity after acetylation with a tyrosine-selective reagent, N-acetylimidazole. The NTPDase3 ATPase activity is increased more than the ADPase activity by this reagent. Several fairly well conserved tyrosine residues (252, 255, and 262) that are located in or very near apyrase conserved region 4a (ACR4a) were mutated. These mutants were all active, but mutation of tyrosine 252 to either alanine or phenylalanine eliminated the activity increase observed after N-acetylimidazole treatment of the wild-type enzyme. This suggests that the acetylation of tyrosine 252 is responsible for the increased activity. Stabilization of quaternary structure has resulted in increased enzyme activities for the NTPDases. However, mutation of these three tyrosine residues did not result in global changes of tertiary or quaternary structure, as measured by Cibacron blue binding, chemical cross linking, and native gel electrophoretic analysis. Nevertheless, disruption of the oligomeric structure with the detergent Triton X-100 abolished the increase in activity induced by this reagent. In addition, mutations that abolished the N-acetylimidazole effect also attenuated the increases of enzyme activity observed after lectin and chemical cross-linking treatments, which were previously attributed to stabilization of the quaternary structure. Thus, we speculate that the acetylation of tyrosine 252 might induce a subtle conformational change in NTPDase3, resulting in the observed increase in activity
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