We propose a general framework for dynamic epistemic logics. It consists of a generic language for DELs and a class of structures, called model transition systems, that describe model transformations in a static way. An MTS can be viewed as a two-layered Kripke model and consequently inherits standard concepts such as bisimulation and bounded morphism from the ordinary Kripke models. In the second half of this article we add the global operator to the language, which enables us to define the (...) notions of a canonical MTS and canonicity of a DEL formula for a property of MTSs. Using these notions, we clarify correspondences between axioms of DELs and properties of MTSs. (shrink)

Honey bees are eusocial insects and the workers inform their nestmates of information regarding the location of food source using symbolic communication, called ‘dance communication’, that are based on their highly advanced learning abilities. Mushroom bodies (MBs), a higher-order center in the honey bee brain, comprise some subtypes/populations of interneurons termed Kenyon cells (KCs) that are distinguished by their cell body size and location in the MBs, as well as their gene expression profiles. Although the role of MBs in learning (...) ability has been studied extensively in the honey bee, the roles of each KC subtype and their evolution in hymenopteran insects remain mostly unknown. This mini-review describes recent progress in the analysis of gene/protein expression profiles and possible functions of KC subtypes/populations in the honey bee. Especially, the discovery of novel KC subtype/population, ‘middle-type KCs’ and ‘KC population expressing FoxP’, necessitated a redefinition of the KC subtype/population. Analysis of the effects of inhibiting gene function in a KC subtype-preferential manner revealed the function of the gene product as well as of the subtype where it is expressed. Genes expressed in a KC subtype/population-preferential manner can be used to trace the differentiation of KC subtypes during the honey bee ontogeny and the possible evolution of KC subtypes in hymenopteran insects. Current findings suggest that the three KC subtypes are unique characteristics to the aculeate hymenopteran insects. Finally, recent application of genome editing for the study of KC subtype functions in the honey bee is described. Genes expressed in a KC subtype-preferential manner can be good candidate target genes for genome editing, because they are likely related to highly advanced brain functions and some of them are dispensable for normal development and sexual maturation in honey bees. (shrink)

A decrease in cortical excitability tends to be easily followed by an increase induced by external stimuli via a mechanism aimed at restoring it; this phenomenon is called “homeostatic plasticity.” In recent years, although intervention methods aimed at promoting motor learning using this phenomenon have been studied, an optimal intervention method has not been established. In the present study, we examined whether subsequent motor learning can be promoted further by a repetitive passive movement, which reduces the excitability of the primary (...) motor cortex before motor learning tasks. We also examined the relationship between motor learning and the brain-derived neurotrophic factor. Forty healthy subjects participated. Subjects were divided into two groups of 20 individuals each. The first group was assigned to perform the motor learning task after an intervention consisting in the passive adduction–abduction movement of the right index finger at 5 Hz for 10 min, while the second group was assigned to perform the task without the passive movement. The motor learning task consisted in the visual tracking of the right index finger. The results showed that the corticospinal excitability was transiently reduced after the passive movement in the RPM condition, whereas it was increased to the level detected in the control condition after the motor learning task. Furthermore, the motor learning ability was decreased immediately after the passive movement; however, the motor performance finally improved to the level observed in the control condition. In individuals carrying the Val/Val genotype, higher motor learning was also found to be related to the more remarkable changes in corticospinal excitability caused by the RPM condition. This study revealed that the implementation of a passive movement before a motor learning tasks did not affect M1 excitatory changes and motor learning efficiency; in contrast, in subjects carrying the Val/Val polymorphism, the more significant excitatory changes in the M1 induced by the passive movement and motor learning task led to the improvement of motor learning efficiency. Our results also suggest that homeostatic plasticity occurring in the M1 is involved in this improvement. (shrink)

In order to achieve flexible and smooth walking, we must accomplish subtasks (e.g., loading response, forward propulsion or swing initiation) within a gait cycle. To evaluate subtasks within a gait cycle, the analysis of muscle synergies may be effective. In the case of walking, extracted sets of muscle synergies characterize muscle patterns that relate to the subtasks within a gait cycle. Although previous studies have reported that the muscle synergies of individuals with disorders reflect impairments, a way to investigate the (...) instability in the activations of muscle synergies themselves has not been proposed. Thus, we investigated the local dynamic stability and orbital stability of activations of muscle synergies across various walking speeds using maximum Lyapunov exponents and maximum Floquet multipliers. We revealed that the local dynamic stability in the activations decreased with accelerated walking speeds. Contrary to the local dynamic stability, the orbital stability of the activations was almost constant across walking speeds. In addition, the increasing rates of maximum Lyapunov exponents were different among the muscle synergies. Therefore, the local dynamic stability in the activations might depend on the requirement of motor output related to the subtasks within a gait cycle. We concluded that the local dynamic stability in the activation of muscle synergies decrease as walking speed accelerates. On the other hand, the orbital stability is sustained across broad walking speeds. (shrink)

As its title suggests, this anthology is a collection of papers presented at a conference on feelings and emotions held in Amsterdam in 2001. One of the symposium’s main goals was to draw some of the most prominent researchers in emotion research together and provide a multi-disciplinary ‘snap shot’ of the state of the art at the turn of the century. In that respect it is truly a cognitive science success story. There are articles from a wide range of fields, (...) encompassing, e.g., philosophy, neuroscience, anthropology, sociology, and psychology. Another.. (shrink)

An undiscovered chapter in the history of architecture comes from the ex-Soviet Republic of Georgia. Poetics of Architecture is the name given to the studioworkshop at the Georgian Technical University set up by the Georgian architect Shota Bostanashvili (1948–2013). From 1990 until his death he delivered insightful, playful and rather provocative lectures on architecture at this university. He preferred to call his architectural philosophy, critical discourse on architecture. Themes ranged from poetics to metapoetics of architecture. His philosophy of architecture (...) is illustrated by some of his designs and executed projects which demonstrate a drift from existentialism to the philosophy of play. This study includes reference to his last building, a project whose demolition Bostanashvili witnessed before passing away. Based on the concept of the return of the sacred, this edifice was a sort of counter movement to technogenic architecture. (shrink)