663 research outputs found

    Concurrent Bursty Behavior of Social Sensors in Sporting Events

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    The advent of social media expands our ability to transmit information and connect with others instantly, which enables us to behave as "social sensors." Here, we studied concurrent bursty behavior of Twitter users during major sporting events to determine their function as social sensors. We show that the degree of concurrent bursts in tweets (posts) and retweets (re-posts) works as a strong indicator of winning or losing a game. More specifically, our simple tweet analysis of Japanese professional baseball games in 2013 revealed that social sensors can immediately react to positive and negative events through bursts of tweets, but that positive events are more likely to induce a subsequent burst of retweets. We also show that these findings hold true across cultures by analyzing tweets related to Major League Baseball games in 2015. Furthermore, we demonstrate active interactions among social sensors by constructing retweet networks during a baseball game. The resulting networks commonly exhibited user clusters depending on the baseball team, with a scale-free connectedness that is indicative of a substantial difference in user popularity as an information source. While previous studies have mainly focused on bursts of tweets as a simple indicator of a real-world event, the temporal correlation between tweets and retweets implies unique aspects of social sensors, offering new insights into human behavior in a highly connected world.Comment: 17 pages, 8 figure

    A Comparative Evaluation of Methods for Evolving a Cooperative Team

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    An evolutionary model of personality traits related to cooperative behavior using a large language model

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    This paper aims to shed light on the evolutionary dynamics of diverse and social populations by introducing the rich expressiveness of generative models into the trait expression of social agent-based evolutionary models. Specifically, we focus on the evolution of personality traits in the context of a game-theoretic relationship as a situation in which inter-individual interests exert strong selection pressures. We construct an agent model in which linguistic descriptions of personality traits related to cooperative behavior are used as genes. The deterministic strategies extracted from Large Language Model (LLM) that make behavioral decisions based on these personality traits are used as behavioral traits. The population is evolved according to selection based on average payoff and mutation of genes by asking LLM to slightly modify the parent gene toward cooperative or selfish. Through preliminary experiments and analyses, we clarify that such a model can indeed exhibit the evolution of cooperative behavior based on the diverse and higher-order representation of personality traits. We also observed the repeated intrusion of cooperative and selfish personality traits through changes in the expression of personality traits, and found that the emerging words in the evolved gene well reflected the behavioral tendency of its personality in terms of their semantics.Comment: 7 pages, 4 figures and 1 tabl

    Research Notes : United States : New independent mutation: msl (Ames 2)

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    Five different populations have been recognized as a source of msl alleles. Genetics studies of male-sterile, female-fertile mutations conducted by Palmer et al. (1978) showed that msl (North Carolina) (T260), msl (Urbana) (T266), msl (Tonica) (T267), and msl (Ames) (T268) are independent mutations at the msl locus. Yee and Jian (1983) reported another mutation at the msl locus, designated Shennong Male-Sterile Soybean L-78-387

    The Role of Social Learning in the Evolution on a Rugged Fitness Landscape

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    The role and importance of social learning have been investigated by many researchers because it is observed in many animals and is expected to play a significant role in cultural phenomena. We explore the coevolution between individual learning and social learning on a rugged fitness landscape as a realistic condition in which they can interact with each other. We demonstrate that social learning allows individuals not to have adaptive traits innately, and thus, has two important roles to enhance individual fitness. First, social learning spreads and keeps the adaptive phenotypes acquired by individual learning. Second, social learning enables individuals to explore a wide range of fitness landscape by the increased population diversity. Based on the difference of the roles of individual and social learning, they can work complementarily in the course of adaptive evolution on the rugged fitness landscape

    Purification and characterization of a flavohemoglobin from the denitrifying fungus Fusarium oxysporum

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    AbstractA flavohemoprotein was purified to homogeneity from the denitrifying fungus Fusarium oxysporum. The purified protein existed as a monomer with a molecular weight of 44 kDa. It was purified in an oxidized form and exhibited the absorption maxima at 401, 540 and 643 nm in its resting form, and at 434 and 555 nm upon reduction with dithionite, respectively. The protein contained 0.5 mol protoheme/mol and 1.1 mol FAD/mol, respectively. When the resting flavohemoprotein was aerobically incubated with NAD(P)H, it was converted to a spectral species that is spectrally very similar to oxyhemoglobins. These properties are characteristics of flavohemoglobins (FHb) of Alcaligenes eutrophus, Escherichia coli, and baker's yeast. Further the amino terminal amino acid sequence of the protein of F. oxysporum was similar to those of these FHbs. These results suggest that the isolated flavohemoprotein of F. oxysporum would be a counterpart of the proteins in the FHb family

    An Online Experimental Framework for Cooperative Relationships With a Real-Time Decision-Making and Rewarding Environment

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    This paper investigates interactions between game theoretical strategies and social relationships in real-time decision-making and rewarding environments. We propose an experimental framework based on techniques of web-based multiplayer online games for this purpose. In our framework, multiple human players, represented as particles in a two-dimensional space of social interactions, can modify their positions and game strategies for the prisoner's dilemma in real time, and receive benefit or cost emerging from both game theoretical and social relationships with neighboring players. We report on experiments with human participants in different conditions of the payoff matrix, which reflects game structures, and the speed of each player, which reflects the ability to change her social relationship. We show that cooperative relationships emerge in real human groups regardless of experimental settings, and show their basic behavioral patterns. We further discuss relationships between behavioral characters of participants in the experiments and their psychological characters to see how their personalities can be reflected in their behavior in such a game theoretical framework, and show that a few psychological characters of participants might reflect their behavioral characters at least in part, but there were variations in these relationships between experimental groups

    Essential functions of the CNOT7/8 catalytic subunits of the CCR4-NOT complex in mRNA regulation and cell viability

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    Shortening of mRNA poly(A) tails (deadenylation) to trigger their decay is mediated mainly by the CCR4-NOT deadenylase complex. While four catalytic subunits (CNOT6, 6L 7, and 8) have been identified in the mammalian CCR4-NOT complex, their individual biological roles are not fully understood. In this study, we addressed the contribution of CNOT7/8 to viability of primary mouse embryonic fibroblasts (MEFs). We found that MEFs lacking CNOT7/8 expression [Cnot7/8-double knockout (dKO) MEFs] undergo cell death, whereas MEFs lacking CNOT6/6L expression (Cnot6/6l-dKO MEFs) remain viable. Co-immunoprecipitation analyses showed that CNOT6/6L are also absent from the CCR4-NOT complex in Cnot7/8-dKO MEFs. In contrast, either CNOT7 or CNOT8 still interacts with other subunits in the CCR4-NOT complex in Cnot6/6l-dKO MEFs. Exogenous expression of a CNOT7 mutant lacking catalytic activity in Cnot7/8-dKO MEFs cannot recover cell viability, even though CNOT6/6L exists to some extent in the CCR4-NOT complex, confirming that CNOT7/8 is essential for viability. Bulk poly(A) tail analysis revealed that mRNAs with longer poly(A) tails are more numerous in Cnot7/8-dKO MEFs than in Cnot6/6l-dKO MEFs. Consistent with elongated poly(A) tails, more mRNAs are upregulated and stabilized in Cnot7/8-dKO MEFs than in Cnot6/6l-dKO MEFs. Importantly, Cnot6/6l-dKO mice are viable and grow normally to adulthood. Taken together, the CNOT7/8 catalytic subunits are essential for deadenylation, which is necessary to maintain cell viability, whereas CNOT6/6L are not

    Soft Magnetic Properties of Electrodeposited Fe-Ni Films Prepared in Citric Acid Based Bath

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    Electrodeposited Fe-Ni films are widely used in device applications. However, there is a growing awareness of the toxicity of the plating bath containing boric acid. In order to avoid boric acid in the deposition process, we have employed a citric acid based bath for electrodeposition of Fe-Ni films and investigated the effect of the acid content in the bath on the structural and magnetic properties of the deposited films. It is found that the Fe content of the film depends largely on the acid concentration and low coercivity values of less than 30 A/m are realized when the Fe content of the film is around 22 at.%. This magnetic softness is attainable in a wide film thickness range between 20 and 120 μm. Our process exhibits a relatively high cathode efficiency of above 55%. Furthermore, a high deposition rate of 170 μm is obtained without sacrificing the magnetic softness of the film by increasing the current density during the deposition. From these results, we conclude that the citric acid based bath is an environmentally friendlier plating bath ideal for mass-production of magnetically soft Fe-Ni films
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