The mitotic spindle contains the machinery responsible for sister chromatid segregation. It is composed of a complex and dynamic array of microtubules, which are nucleated from the spindle poles. Studies of yeast spindle functions by molecular genetic analysis and by in vitro functional analysis have identified proteins that are mitosis‐specific and present at very low concentrations in the cell, and have revealed the molecular bases of several processes required for the formation and functioning of the mitotic spindle. Here I review (...) the current knowledge of the processes that are common to most eukaryotes: microtubule nucleation at the spindle poles, bipolar spindle assembly, maintenance of the spindle structure, chromosome attachment to the spindle and chromosome separation on the spindle. (shrink)

古代西洋より伝わったとされる対称美の分析―黄金比。しかし、本書では葛飾北斎、歌川広重など偉大な日本の先人たちはすでに、黄金比を会得していたことを証明しています。なぜ、北斎がすばらしいのか?なぜ、俳句は 5・7・5なのか?富士山はどの角度から眺めるのが一番美しいのか?すべては黄金比を使い、美の世界を数値化することで見える新たな世界。初めて黄金比を用い、実例を分析した本書は日本初の試み。.

Collection of texts published previously.

Heterogeneous beliefs and decision processes generate positive externalities for social and economic systems, analogous to biodiversity in biological systems. Although some aspects of biodiversity (e.g., pests, parasites and bacteria) can lead to ecological and economic problems, biodiversity provides flows of beneficial ecological services and is widely regarded as a valuable natural resource and informational asset, whose value increases as we learn more and science progresses (Wilson in Bioscience 35(11):700–706, 1985). Heterogeneous beliefs and decision processes (and heterogeneous behaviors they generate) similarly (...) provide flows of beneficial economic services. Behavioral diversity should therefore be seen as a natural resource and informational asset likely to improve human wellbeing in surprising ways in the future. Paternalistic policies motivated by the goal of “correcting” allegedly suboptimal beliefs and behavior that diverge from expert recommendations jeopardize behavioral diversity at a substantial cost to social welfare. The risk of encroaching on this beneficial behavioral heterogeneity with policies that aim to induce behavioral and belief monocultures should be included explicitly as costs when evaluating nudges and other paternalistic policies. (shrink)

Ashok Aklujkar, Indian Sanskritist and Indologist; contributed articles.

This chapter contains section titled: Looking at the Text (T 1.3.14) Three Readings Reconstructions and Speculations References Further Reading.

Actions shape what we see and memorize. A previous study suggested the interaction between motor and memory systems by showing that memory encoding for task-irrelevant items was enhanced when presented with motor-response cues. However, in the studies on the attentional boost effect, it has been revealed that detection of the target stimulus can lead to memory enhancement without requiring overt action. Thus, the direct link between the action and memory remains unclear. To exclude the effect of the target detection process (...) as a potential confounder, this study assessed the benefit of action for memory by separating items from the response cue in time. In our pre-registered online experiment, participants responded to visual Go cues by pressing a key or counting while ignoring No-go cues. In each trial, two task-irrelevant images were sequentially presented after the cue disappearance. After encoding the Go/No-go tasks, participants performed a surprise recognition memory test for those images. Importantly, we quantified the impact of overt execution of the action by comparing memories with and without motor response and the impact of covert motor processes by comparing memory between the motor and cognitive tasks. The results showed no memory differences between Go and No-go trials in the motor task. This means that the execution itself was not critical for memory enhancement. However, the memory performance in the motor No-go trials was higher than that in the cognitive No-go trials, only for the items presented away from the cues in time. Therefore, engaging the motor task itself could increase incidental memory for the task-irrelevant items compared to a passive viewing situation. We added empirical evidence on the online interaction between action and memory encoding. These memory advantages could be especially brought in action preparation and planning. We believe this fact may expand our present understanding of everyday memory, such as active learning. (shrink)

We examined amygdala subregion volumes in patients with a first episode of major depression and in healthy subjects. Covariate-adjusted linear regression was performed to compare the MD and healthy groups, and adjustments for age, gender, and total estimated intracranial volume showed no differences in amygdala subregion volumes between the healthy and MD groups. Within the MD group, we examined the association between amygdala subregion volume and the 17-item Hamilton Rating Scale for Depression score and the HAMD subscale score, and found (...) no association in the left amygdala. In the right amygdala, however, there was an inverse linear association between the HAMD total and the HAMD core and lateral nucleus and anterior-amygdaloid-regions. Furthermore, an inverse linear association was seen between the HAMD psychic and the lateral nucleus, anterior-amygdaloid-regions, transition, and whole amygdala. The findings of this study suggest that the severity of MD and some symptoms of MD are associated with right amygdala volume. There have been few reports on the relationship between MD and amygdala subregional volume, and further research is needed to accumulate more data for further validation. (shrink)

A demanding introduction to logic and critical thinking, this book offers more traditional means of teaching the art of reasoning at a time when the field has become almost mathematical. Francis Dauer has rethought the framework for teaching reasoning in general and formal logic in particular, the desired epistemological context, and the role of the fallacies. The result is a coherent and very readable work, informed by Dauer's extensive experience teaching and writing on the subject.

Some spatio-temporal structures are easier to transfer implicitly in sequential learning. In this study, we investigated whether the consistent reversal of triads of learned components would support the implicit transfer of their temporal structure in visuomotor sequence learning. A triad comprised three sequential button presses ([1][2][3]) and seven consecutive triads comprised a sequence. Participants learned sequences by trial and error, until they could complete it 20 times without error. Then, they learned another sequence, in which each triad was reversed ([3][2][1]), (...) partially reversed ([2][1][3]), or switched so as not to overlap with the other conditions ([2][3][1] or [3][1][2]). Even when the participants did not notice the alternation rule, the consistent reversal of the temporal structure of each triad led to better implicit transfer; this was confirmed in a subsequent experiment. These results suggest that the implicit transfer of the temporal structure of a learned sequence can be influenced by both the structure and consistency of the change. (shrink)

This study adopted an empirical method to investigate lay people’s attitudes toward the bioethical issues of human-animal chimeric brains. The results of online surveys showed that (1) people did not entirely reject chimeric brain research, but showed slightly more negative responses than ordinary animal testing; and that (2) their ethical concerns arose in connection with the perception that chimerism in the brain would humanize the animal. This means that people’s psychology was consistent with the ethical argument that crossing the human-animal (...) boundary would bring moral confusion to our society. Meanwhile, it was not in line with another argument that moral status depended on having high capacities, and that chimerism would cause a problem if it enhanced animals’ capacities. Furthermore, this study analyzed additional psychological factors related to people’s moral judgment and the relationship among those factors. Several psychological factors, such as the perception that chimeric brain research is unnatural, were identified as mediating the relationship between perception of animal humanization and ethical concerns about creating and using chimeric brains. Introducing an empirical approach to the ethics of human-animal chimeric brains brought two findings: (1) this study informed us of socially shared intuition regarding this novel technology; and (2) it unveiled the psychological processes behind people’s ethical concerns in more detail than they spontaneously mentioned. These findings will help to build normative arguments and future policies that are understandable and acceptable to society. (shrink)

Physics first became established in Australia and Japan at the same period, during the final quarter of the nineteenth and the first years of the twentieth century. A comparison of the processes by which this happened in these two developing countries on the Pacific rim shows that, despite the great cultural differences that existed, and that might have been expected to have been a source of major differences in national receptiveness to the new science, there were in fact many parallels (...) between the patterns of development in the two cases. Identifying these enables us to draw attention to a number of significant features of the physics discipline more generally at this period. Such differences as emerge in the early history of physics in the two countries seem to have arisen more from the different political situations that prevailed than from anything else; in particular they reflect the fact that Australia was a part of the British Empire while Japan was an independent political power. (shrink)

In 1914, the physics discipline had reached a very similar stage of development in Australia and Japan. A generation later the paths of development had considerably diverged. A systematic comparison of the evolution of physics in the two countries during these years identifies factors—political, economic and cultural—that led to this divergence, but it also uncovers a number of underlying parallels.

By employing binary committee choice problems, this paper investigates how varying or eliminating feedback about payoffs affects: subjects’ learning about the underlying relationship between their nominal voting weights and their expected payoffs in weighted voting games; the transfer of acquired learning from one committee choice problem to a similar but different problem. In the experiment, subjects choose to join one of two committees and obtain a payoff stochastically determined by a voting theory. We found that: subjects learned to choose the (...) committee that generates a higher expected payoff even without feedback about the payoffs they received; there was statistically significant evidence of “meaningful learning” only for the treatment with no payoff-related feedback. This finding calls for re-thinking existing models of learning to incorporate some type of introspection. (shrink)

IntroductionPrevious transcranial magnetic stimulation studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements.MethodTen healthy right-handed subjects performed four finger tapping tasks with the index finger: simple tapping task, Real-word task, Pseudoword task, and Visually guided tapping task. In the Tap task, the subject (...) performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word. Because the action had a specific purpose, this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition in the resting first dorsal interosseous muscle.ResultsWe found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions.DiscussionWe found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis. (shrink)