Slow dynamics perspectives on the Embodied-Brain Systems Science

AbstractRecent researches point out the importance of the fast-slow cognitive process and learning process of self-body. Bayesian perspectives on the cognitive system also attract research attentions. The view of fast-slow dynamical system has long attracted wide range of attentions from physics to the neurobiology. In many research fields, there is a vast well-organized and coherent behavior in the multi degrees-of-freedom. This behavior matches the mathematical fact that fast-slow system is essentially described with a few variables. In this paper, we review the mathematical basis for understanding the fast-slow dynamical systems. Additionally, we review the basis of Bayesian statistics and provide a fast-slow perspective on the Bayesian inference

Factors related to the fatigue of relief workers in areas affected by the Great East Japan Earthquake : survey results 2.5 years after the disaster

Background: After the Great East Japan Earthquake (March 11, 2011), the fatigue of relief workers became a major problem in affected areas. In the present study, we conducted a questionnaire survey 2.5 years post-disaster identifying factors related to the fatigue of relief workers. Methods: This survey was cross-sectional and participants (N = 119) were relief workers living in affected areas. We used a self-administered questionnaire which included participants’ current problems, sources of strong feeling of loss, psychological distress and compassion fatigue. Based on answers (Yes/No) to the fatigue item, we created 2 groups; a Fatigue-group and a Non-fatigue group. We employed bivariate analysis on items with significant differences between the two groups and entered them into a multivariable logistic regression model. Results: Fifty-seven (48%) reported that they were “very tired” and were assigned to the Fatigue group. The total score of the 6-item Kessler Psychological Distress Scale (K6) and each subscale score (burnout, secondary trauma, and compassion satisfaction) of the Professional Quality of Life measure (Pro-QOL) in the Fatigue group were significantly higher than those in the Non-fatigue group. There were significant differences between the two groups for 11 items relating to current problems and sources of strong feelings of loss, and the following items were extracted as factors related to the fatigue of relief workers: loss of trust in others (adjusted OR, 10.03: 95%CI, 2.30–43.79), no confidence to continue work (adjusted OR, 6.27: 95%CI, 1.72–22.83), loss of important person(s) (adjusted OR, 5.58: 95%CI, 2.05–15.19), and sleep disturbance (adjusted OR, 5.14: 95%CI, 1.93–13.67). Conclusion: Many relief workers who reported fatigue had experienced various losses and current problems. Adequate consideration and care systems for local relief workers with fatigue should be given for a long-period after a disaster and it is important for the workers themselves to continue accepting support from others and maintaining self-care habits

Algivore or phototroph?: Plakobranchus ocellatus (Gastropoda) continuously acquires kleptoplasts and nutrition from multiple algal species in nature

The sea slug Plakobranchus ocellatus (Sacoglossa, Gastropoda) retains photosynthetically active chloroplasts from ingested algae (functional kleptoplasts) in the epithelial cells of its digestive gland for up to 10 months. While its feeding behavior has not been observed in natural habitats, two hypotheses have been proposed: 1) adult P. ocellatus uses kleptoplasts to obtain photosynthates and nutritionally behaves as a photoautotroph without replenishing the kleptoplasts; or 2) it behaves as a mixotroph (photoautotroph and herbivorous consumer) and replenishes kleptoplasts continually or periodically. To address the question of which hypothesis is more likely, we examined the source algae for kleptoplasts and temporal changes in kleptoplast composition and nutritional contribution. By characterizing the temporal diversity of P. ocellatus kleptoplasts using rbcL sequences, we found that P. ocellatus harvests kleptoplasts from at least 8 different siphonous green algal species, that kleptoplasts from more than one species are present in each individual sea slug, and that the kleptoplast composition differs temporally. These results suggest that wild P. ocellatus often feed on multiple species of siphonous algae from which they continually obtain fresh chloroplasts. By estimating the trophic position of wild and starved P. ocellatus using the stable nitrogen isotopic composition of amino acids, we showed that despite the abundance of kleptoplasts, their photosynthates do not contribute greatly to the nutrition of wild P. ocellatus, but that kleptoplast photosynthates form a significant source of nutrition for starved sea slugs. The herbivorous nature of wild P. ocellatus is consistent with insights from molecular analyses indicating that kleptoplasts are frequently replenished from ingested algae, leading to the conclusion that natural populations of P. ocellatus do not rely on photosynthesis but mainly on the digestion of ingested algae