110 research outputs found

    Design of a fuzzy affective agent based on typicality degrees of physiological signals

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    Conference paper presented at International Conference on Information Processing and Management in July 2014Physiology-based emotionally intelligent paradigms provide an opportunity to enhance human computer interactions by continuously evoking and adapting to the user experiences in real-time. However , there are unresolved questions on how to model real- time emotionally intelligent applications through mapping of physiological patterns to users ' affective states. In ·this study, we consider an approach for design of fuzzy affective agent based on the concept of typicality. We propose the use of typicality degrees of physiological patterns to construct the fuzzy rules representing the continuous transitions of user 's affective states. The approach was tested· on experimental data in which physiological measures were recorded on players involved in an action game to characterize various gaming experiences . We show that , in addition to exploitation of the results to characterize users ' affective states through .typicality degrees, this approach is a systematic way to automatically define fuzzy rules from experimental data for an affective agent to be used in real -time continuous assessment of user's affective states.Physiology-based emotionally intelligent paradigms provide an opportunity to enhance human computer interactions by continuously evoking and adapting to the user experiences in real-time. However , there are unresolved questions on how to model real- time emotionally intelligent applications through mapping of physiological patterns to users ' affective states. In ·this study, we consider an approach for design of fuzzy affective agent based on the concept of typicality. We propose the use of typicality degrees of physiological patterns to construct the fuzzy rules representing the continuous transitions of user 's affective states. The approach was tested· on experimental data in which physiological measures were recorded on players involved in an action game to characterize various gaming experiences . We show that , in addition to exploitation of the results to characterize users ' affective states through .typicality degrees, this approach is a systematic way to automatically define fuzzy rules from experimental data for an affective agent to be used in real -time continuous assessment of user's affective states

    Expression dynamics of metalloproteinases during mandibular bone formation: association with Myb transcription factor

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    As the dentition forms and becomes functional, the alveolar bone is remodelled. Metalloproteinases are known to contribute to this process, but new regulators are emerging and their contextualization is challenging. This applies to Myb, a transcription factor recently reported to be involved in bone development and regeneration. The regulatory effect of Myb on Mmps expression has mostly been investigated in tumorigenesis, where Myb impacted the expression of Mmp1, Mmp2, Mmp7, and Mmp9. The aim of this investigation was to evaluate the regulatory influence of the Myb on Mmps gene expression, impacting osteogenesis and mandibular bone formation. For that purpose, knock-out mouse model was used. Gene expression of bone-related Mmps and the key osteoblastic transcription factors Runx2 and Sp7 was analysed in Myb knock-out mice mandibles at the survival limit. Out of the metalloproteinases under study, Mmp13 was significantly downregulated. The impact of Myb on the expression of Mmp13 was confirmed by the overexpression of Myb in calvarial-derived cells causing upregulation of Mmp13. Expression of Mmp13 in the context of other Mmps during mandibular/alveolar bone development was followed in vivo along with Myb, Sp7 and Runx2. The most significant changes were observed in the expression of Mmp9 and Mmp13. These MMPs and MYB were further localized in situ by immunohistochemistry and were identified in pre/osteoblastic cells as well as in pre/osteocytes. In conclusion, these results provide a comprehensive insight into the expression dynamics of bone related Mmps during mandibular/alveolar bone formation and point to Myb as another potential regulator of Mmp13

    Non-apoptotic functions of caspase-7 during osteogenesis

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    Caspase-3 and -7 are generally known for their central role in the execution of apoptosis. However, their function is not limited to apoptosis and under specific conditions activation has been linked to proliferation or differentiation of specialised cell types. In the present study, we followed the localisation of the activated form of caspase-7 during intramembranous (alveolar and mandibular bones) and endochondral (long bones of limbs) ossification in mice. In both bone types, the activated form of caspase-7 was detected from the beginning of ossification during embryonic development and persisted postnatally. The bone status was investigated by microCT in both wild-type and caspase-7-deficient adult mice. Intramembranous bone in mutant mice displayed a statistically significant decrease in volume while the mineral density was not altered. Conversely, endochondral bone showed constant volume but a significant decrease in mineral density in caspase-7 knock-out mice. Cleaved caspase-7 was present in a number of cells that did not show signs of apoptosis. PCR array analysis of the mandibular bone of caspase-7-deficient versus wild-type mice pointed to a significant decrease in mRNA levels for Msx1 and Smad1 in early bone formation. These observations might explain the decrease in the alveolar bone volume of adult knock-out mice. In conclusion, this study is the first to report a non-apoptotic function of caspase-7 in osteogenesis and also demonstrates further specificities in endochondral versus intramembranous ossification

    NMR discrimination in nonrigid prochiral solutes dissolved in chiral liquid crystals: symmetry considerations

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    Enantiodiscrimination in the NMR spectra of flexible prochiral solutes dissolved in chiral liquid crystals (CLCs) is reviewed and compared with the analog phenomenon in such rigid solutes. In rigid prochiral solutes, the discrimination is brought about by the cancellation of improper symmetry elements upon dissolving in CLC within the frame of solute-solvent ordering mechanisms. If this reduction in symmetry renders the ordering of enantiotopic sites dissimilar, spectral discrimination may be observed. Symmetry considerations indicate that this is only possible for improper nonaxial groups lacking inversion symmetry. Nonrigid prochiral solutes consist of rapidly (on the NMR timescale) interconverting enantiomers, in which the racemization is accompanied by exchange of nonequivalent sites. These sites become, on the average, enantiotopically related, and in CLC, they exhibit spectral discrimination. The mechanism of the effect and the symmetry selection rules are different for the two cases. Specifically, the discrimination in flexible prochiral compounds results from the different ordering of the interchanging enantiomers in CLC. Using Altman's definition of average symmetry (Proc. R. Soc. A, 1967, 298, 184), selection rules for the phenomenon are derived. It follows that chiral discrimination in nonrigid prochiral solutes is much more abundant and can occur in all symmetry types except those possessing inversion. In particular, contrary to earlier thoughts, the effect can occur in compounds with axial symmetry. Illustrative examples of such studies with particular emphasis on compounds with average axial symmetry of the type D3h, C3v and C3h are reviewed in this contribution
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