Dynamical pinning of domain wall in magnetic nanowire induced by Walker breakdown

Transmission probability of a domain wall through a magnetic nanowire is investigated as a function of the external magnetic field. Very intriguing phenomenon is found that the transmission probability shows a significant drop after exceeding the threshold driving field, which contradicts our intuition that a domain wall is more mobile in the higher magnetic field. The micromagnetics simulation reveals that the domain wall motion in the wire with finite roughness causes the dynamical pinning due to the Walker breakdown, which semi-quantitatively explains our experimental results.Comment: 17 pages, 4 figure

UVA1 genotoxicity is mediated not by oxidative damage but by cyclobutane pyrimidine dimers in normal mouse skin

UVA1 induces the formation of 8-hydroxy-2′-deoxyguanosines (8-OH-dGs) and cyclobutane pyrimidine dimers (CPDs) in the cellular genome. However, the relative contribution of each type of damage to the in vivo genotoxicity of UVA1 has not been clarified. We irradiated living mouse skin with 364-nm UVA1 laser light and analyzed the DNA damage formation and mutation induction in the epidermis and dermis. Although dose-dependent increases were observed for both 8-OH-dG and CPD, the mutation induction in the skin was found to result specifically from the CPD formation, based on the induced mutation spectra in the skin genome: the dominance of C → T transition at a dipyrimidine site. Moreover, these UV-specific mutations occurred preferentially at the 5′-TCG-3′ sequence, suggesting that CpG methylation and photosensitization-mediated triplet energy transfer to thymine contribute to the CPD-mediated UVA1 genotoxicity. Thus, it is the CPD formation, not the oxidative stress, that effectively brings about the genotoxicity in normal skin after UVA1 exposure. We also found differences in the responses to the UVA1 genotoxicity between the epidermis and the dermis: the mutation induction after UVA1 irradiation was suppressed in the dermis at all levels of irradiance examined, whereas it leveled off from a certain high irradiance in the epidermis

ゴルジノラクトンの合成研究

講演番号：4ⅢL 2

Control of Domain Wall Position by Electrical Current in Structured Co/Ni Wire with Perpendicular Magnetic Anisotropy

We report the direct observation of the current-driven domain wall (DW) motion by magnetic force microscopy in a structured Co/Ni wire with perpendicular magnetic anisotropy. The wire has notches to define the DW position. It is demonstrated that single current pulses can precisely control the DW position from notch to notch with high DW velocity of 40 m/s.Comment: 12 pages, 3 figure

Exception Conjunctions and Sika-nai Constructions : A Preliminary Study

In this paper, I will present two proposals. First, I propose that sika-nai constructions in Japanese should be analyzed in the same way as exception conjunctions in English, paying attention to the fact that NPs followed by sika can occur with additional NPs with a Case-particle. A motivation for my proposal comes from some semantic similarities between sika-nai constructions and exception conjunctions. Further, I will argue that additional NPs move to sika NPs for getting an appropriate interpretation at LF, along the line of Reinhart's (1991) analysis that a correlate moves to an except phrase for an interpretation, contrary to the recent minimalist assumption that movement is driven by some morphological features

Case valuation after scrambling: Nominative objects in Japanese

This paper provides new evidence for the claim that nominative objects in Japanese undergo overt movement without remaining at their base-generated positions, based on a variant of the construction which has not received as much attention as its complex predicate counterpart. It is then argued that the overt movement is scrambling. Departing from the general assumption, this paper investigates the hypothesis that an application of scrambling affects Case valuation, which was originally investigated by Fukui & Nishigauchi (1992) and Fukui (1995) (cf. Kuno 2002). Under the proposal, a nominative object is scrambled from its original position to the edge of vP, where nominative Case can be assigned. When scrambling does not take place, the object stays in-situ and receives accusative Case at its base-generated position. In other words, the Case alternation is contingent on the application of scrambling, which captures the optionality of the Case alternation in terms of that of scrambling. It is also proposed that the proposed mechanism of the Case alternation be restricted in such a way that the landing site and the base-generated position are included in the same transferred domain. Given this restriction, it is also possible to correctly capture cases where scrambling does not affect case valuation. The proposed analysis crucially adopts the hypothesis proposed by Chomsky (2001), where the transferred domain is the complement of a phase head. To the extent that the proposed analysis is successful, this paper lends support to this characterization of transferred domains

Some Split Antecedents are not Split

Takano (1999) argues that "oblique movement" (movement of an element to another element that does not dominate that element) plays a crucial role in making a constituent in the cleft construction which has multiple foci in Japanese. This paper argues that oblique movement makes a constituent at LF, based on the 'split antecedents 'phenomena in Japanese. Antecedents ofanaphors can be split on the surface in Japanese unlike English. I propose that oblique movement combines discontinuous antecedents on the surface into a single constituent at LF in Japanese. In this paper, I reduce the difference with respect to split antecedents between Japanese and English to the presence/absence of oblique movement