Spread of Risk Information Through Microblogs: Twitter Users with More Mutual Connections Relay News That is More Dreadful1

In elucidating the spread of risk information through microblogging, it is important to understand the behaviors of numerous average users, in addition to the activities of authorities. We followed the transmission pathways of 10 actual widely spread tweets concerning several risk information topics, including natural disasters, nuclear disasters, and infectious diseases, and we identified the types of risk that affected retweeting by classifying each tweet based on Slovic's risk-perception model. Furthermore, we examined the types of users who did and did not retweet the information. Users with few connections in the form of followers (i.e., people who are following a user) or followees (people a user is following), or with a low ratio of mutual followers within their connections, had a tendency to retweet a large amount of risk information, regardless of the type of risk involved. On the other hand, users with a high ratio of mutual followers exhibited a greater tendency to retweet risk information when it was perceived as dreadful, though they did not retweet risk information much on the whole. These results suggest that there are two mechanisms by which risk information is spread within the Twitter network: information exchange and social sharing of personal reactions.     

Effects of receptive listening on the congruence of speakers' response latencies in dialogues

The present study investigated the receptiveness of speakers toward conversational partners in dialogues by comparing duration of response latencies in both Compromise and Debate conditions. 12 dyads of speakers holding opposing opinions participated in a 15-min. dialogue. Six dyads in the Compromise condition reached a conclusion through discussion and consideration of the partner's opinion. The six dyads in the Debate condition imposed their opinion on the conversational partner. Analysis indicated that in compromise dialogues, the response latencies of the conversational partners become similar over the time course, while in debate diaogues, the response latency does not become similar, suggesting that speakers having a receptive attitude adjust their response latencies to match the partner's. The role of congruence of response latencies in dyadic communication was discussed.     

A review of time-motion analysis and combat development in mixed martial arts matches at regional level tournaments

Mixed martial arts (MMA) have become a fast-growing worldwide expansion of martial arts competition, requiring high level of skill, physical conditioning, and strategy, and involving a synthesis of combat while standing or on the ground. This study quantified the effort-pause ratio (EP), and classified effort segments of stand-up or groundwork development to identify the number of actions performed per round in MMA matches. 52 MMA athletes participated in the study (M age = 24 yr., SD = 5; average experience in MMA = 5 yr., SD = 3). A one-way analysis of variance with repeated measurements was conducted to compare the type of action across the rounds. A chi-squared test was applied across the percentages to compare proportions of different events. Only one significant difference (p < .05) was observed among rounds: time in groundwork of low intensity was longer in the second compared to the third round. When the interval between rounds was not considered, the EP ratio (between high-intensity effort to low-intensity effort plus pauses) was 1:2 to 1:4. This ratio is between ratios typical for judo, wrestling, karate, and taekwondo and reflects the combination of ground and standup techniques. Most of the matches ended in the third round, involving high-intensity actions, predominantly executed during groundwork combat.     

A reduction rule for Peirce formula

A reduction rule is introduced as a transformation of proof figures in implicational classical logic. Proof figures are represented as typed terms in a -calculus with a new constant P ⁽⁽⁾⁾. It is shown that all terms with the same type are equivalent with respect to -reduction augmented by this P-reduction rule. Hence all the proofs of the same implicational formula are equivalent. It is also shown that strong normalization fails for P-reduction. Weak normalization is shown for P-reduction with another reduction rule which simplifies of (( ) ) into an atomic type.This work was partially supported by a Grant-in-Aid for General Scientific Research No. 05680276 of the Ministry of Education, Science and Culture, Japan and by Japan Society for the Promotion of Science. Hiroakira Ono     

Neural bases of focusing attention in working memory: An fMRI study based on group differences

Using fMRI, we investigated neural substrates for focusing attention in working memory. To explore this focusing effect, two kinds of reading span test (RST), focused and nonfocused, were performed. In the focused RST (F-RST), the target word to be maintained was the focus word in the sentence. In the nonfocused RST (NF-RST), the target word was not the focus word in the sentence. In both RST conditions, significant activations were found in three main regions: left dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and left superior parietal lobule (SPL). In addition, fMRI signal changes increased in the left SPL in the NF-RST condition. These findings suggest that the neural substrates of focusing attention are based on SPL and ACC-DLPFC networks. Furthermore, there were group differences in the focusing effect between high-span and low-span subjects: High-span subjects showed focusing effects (supported by SPL control) greater than those of low-span subjects.     

The Effect of Positive Emotions with Different Arousal Levels on Thought–Action Repertoires1,2

This study examined whether the induction of different states of arousal via positive emotions broadens thought–action repertoires. Sixty-two Japanese undergraduate and graduate students were randomly assigned to (a) high-arousal positive emotion, (b) low-arousal positive emotion, and (c) neutral groups, after which they watched a 3-min film clip. Participants completed the Affect Grid to confirm their mood state before and after watching the film. Following this, they completed the Twenty Statements Test, which measures thought–action repertoires. A one-way analysis of variance was conducted on the Twenty Statements Test score. The results showed that high-arousal positive emotion broadened thought–action repertoires to a greater extent than did low-arousal positive emotion and the neutral state, while low-arousal positive emotion broadened such repertoires to a greater extent than did the neutral state. We discuss the different effects of high- and low-arousal positive emotions on thought–action repertoires.     

Syntactical investigations intoBI logic andBB′I logic

In this note, we will study four implicational logicsB, BI, BB and BBI. In [5], Martin and Meyer proved that a formula is provable inBB if and only if is provable inBBI and is not of the form of » . Though it gave a positive solution to theP - W problem, their method was semantical and not easy to grasp. We shall give a syntactical proof of the syntactical relation betweenBB andBBI logics. It also includes a syntactical proof of Powers and Dwyer's theorem that is proved semantically in [5]. Moreover, we shall establish the same relation betweenB andBI logics asBB andBBI logics. This relation seems to say thatB logic is meaningful, and so we think thatB logic is the weakest among meaningful logics. Therefore, by Theorem 1.1, our Gentzentype system forBI logic may be regarded as the most basic among all meaningful logics. It should be mentioned here that the first syntactical proof ofP - W problem is given by Misao Nagayama [6].Presented byHiroakira Ono     

A new algorithm for the least-squares solution in factor analysis

A new algorithm to obtain the least-squares or MINRES solution in common factor analysis is presented. It is based on the up-and-down Marquardt algorithm developed by the present authors for a general nonlinear least-squares problem. Experiments with some numerical models and some empirical data sets showed that the algorithm worked nicely and that SMC (Squared Multiple Correlation) performed best among four sets of initial values for common variances but that the solution might sometimes be very sensitive to fluctuations in the sample covariance matrix.Numerical computation was made on a NEAC S-1000 computer in the Computer Center, Osaka University.