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We studied the quantum critical behavior of the second antiferromagnetic (AF) phase in the heavily electron-doped high-Tc pnictide, LaFeAsO1−xHx by using 75 As and 1 H nuclear-magneticresonance (NMR) technique. In the second AF phase, we observed a spatially modulated spindensity-wave-like state up to x=0.6 from the NMR spectral lineshape and detected a low-energy excitation gap from the nuclear relaxation time T1 of 75 As. The excitation gap closes at the AF quantum critical point (QCP) at x ≈ 0.49. The superconducting (SC) phase in a lower-doping regime contacts the second AF phase only at the AF QCP, and both phases are segregated from each other. The absence of AF critical fluctuations and the enhancement of the in-plane electric anisotropy are key factors for the development of superconductivity.

Many studies have examined defensive strategies of adult lepidopterans against bird predation. However, detailed field observations that describe how lepidopterans are hunted by wild birds are quite limited. I observed foraging behavior of wild tree sparrows on adult lepidopterans from May to June 2006 at Mt Yoshida, Kyoto, Japan. A total of 253 foraging attempts on at least 14 species of lepidopterans were observed. The tree sparrows attacked both resting and flying lepidopterans. When a tree sparrow approached a resting lepidopteran, the lepidopteran frequently flew to escape predation. The number of feeding attempts for resting and flying lepidopterans was 215 and 38, respectively. This result indicates that resting lepidopterans are the main target of predation by the tree sparrow. It is therefore considered that reducing the risk of detection is important for lepidopterans to avoid predation by the tree sparrow. Coloration as crypsis is probably effective in this respect.