322 research outputs found

    Toward Security Verification against Inference Attacks on Data Trees

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    This paper describes our ongoing work on security verification against inference attacks on data trees. We focus on infinite secrecy against inference attacks, which means that attackers cannot narrow down the candidates for the value of the sensitive information to finite by available information to the attackers. Our purpose is to propose a model under which infinite secrecy is decidable. To be specific, we first propose tree transducers which are expressive enough to represent practical queries. Then, in order to represent attackers' knowledge, we propose data tree types such that type inference and inverse type inference on those tree transducers are possible with respect to data tree types, and infiniteness of data tree types is decidable.Comment: In Proceedings TTATT 2013, arXiv:1311.505

    Relationships between mating tactics and male traits such as body size and fluctuating asymmetry in the Japanese scorpionfly

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    Fluctuating asymmetry (FA) is defined as small, random deviations from perfect bilateral symmetry in a morphological trait. It has sometimes been used as an indicator of male quality because it affects male mating success. In the Japanese scorpionfly, Panorpa japonica, males are known to use two mating tactics, donation of nuptial gifts and forced mating. In P. japonica, low FA males are more likely to win a competition with another male, and females prefer low FA male sex pheromones. However, no studies have been conducted on the effect of FA on the mating tactics adopted by males. In the present study, we first observed the mating behaviors of P. japonica and classified these into three patterns: (1) nuptial gifting, (2) forced mating, and (3) feeding mating. Second, we investigated the relationships between mating tactics and male traits, including body size, FA, and weapon size. The results showed a positive correlation between absolute FA and mating duration only in the case of feeding mating. We discuss the reasons why this significant correlation was found in P. japonica

    Spin-state transition and phase separation in multi-orbital Hubbard model

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    We study spin-state transition and phase separation involving this transition based on the milti-orbital Hubbard model. Multiple spin states are realized by changing the energy separation between the two orbitals and the on-site Hund coupling. By utilizing the variational Monte-Carlo simulation, we analyze the electronic and magnetic structures in hole doped and undoped states. Electronic phase separation occurs between the low-spin band insulating state and the high-spin ferromagnetic metallic one. Difference of the band widths in the two orbitals is of prime importance for the spin-state transition and the phase separation.Comment: 5 pages, 5 figure

    Freezing or death feigning? Beetles selected for long death feigning showed different tactics against different predators

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    Prey evolve antipredator strategies against multiple enemies in nature. We examined how a prey species adopts different predation avoidance tactics against pursuit or sit-and-wait predators. As prey, we used three strains of Tribolium beetles artificially selected for short (short strain) or long (long strain) duration of death feigning, and a stock culture (base population). Death feigning is known to be effective for evading a jumping spider in the case of the long strains, while the present study showed that the long-strain beetles used freezing against a sit-and-wait type predator, Amphibolus venator, in this study. The short- strain beetles were more easily oriented toward predators. The time to predation was also shorter in the short strains compared to the long strains. The results showed that, as prey, the short strains displayed the same behavior, escaping, against both types of predators. Traditionally, death feigning has been thought to be the last resort in a series of antipredator avoidance behaviors. However, our results showed that freezing and death feigning were not parts of a series of behaviors, but independent strategies against different predators, at least for long-strain beetles. We also examined the relationship between a predator's starvation level and its predatory behavior. In addition, the orientation behavior toward and predation rate on the prey were observed to determine how often the predatory insect attacked the beetles
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