An Analysis of Foreign Policies of the Obama Administration: From January 2009 to May 2010 (Japanese)

The foreign and national security policy team under President Obama consists mostly of moderate Democrats and moderate/realist Republicans, although Obama originally came from a group close to anti-war/leftist activists of the Democratic Party. Obama started with many bold initiatives on multi-fronts based on the belief in rationality, calling for negotiations even with North Korea and Iran. The tone of Obama's foreign policies, however, has undergone a significant change. He is now very tough with Iran. The policies toward China have also shifted significantly. His only concrete achievement in foreign policy area has been the nuclear reduction agreement with Russia, which he obtained without compromising a lot on missile defense. Some journalists now characterize his foreign policies as realist. It is premature to judge on this, but we need to be aware of the change and its implications.

Higgs potential in a minimal S3 invariant extension of the standard model

金沢大学大学院自然科学研究科物理学金沢大学理学部Minimal S3 invariant Higgs potential with real soft S 3 breaking masses is investigated. It is required that without having a problem with triviality, all physical Higgs bosons, except one neutral one, become heavy ≳ 10 TeV in order to sufficiently suppress flavor-changing neutral currents. There exist three nonequivalent soft mass terms that can be characterized according to their discrete symmetries, and the one that breaks S3 completely. The S2′ invariant vacuum expectation values (VEVs) of the Higgs fields are the most economic VEVs in the sense that the freedom of VEVs can be completely absorbed into the Yukawa couplings so that it is possible to derive, without referring to the details of the VEVs, the most general form for the fermion mass matrices in minimal S3 extension of the standard model. We find that except for the completely broken case of the soft terms, the S2′ invariant VEVs are unique VEVs that satisfy the requirement of heavy Higgs bosons. It is found that they also correspond to a local minimum in the completely broken case. ©2004 The American Physical Society

米国における気候変動政策 : 米国および日韓の地球環境政策ネットワーク調査からの考察 (特集 地球環境政治と市民社会)

近年政治学では政策決定過程に及ぼすネットワークの役割に関心が集っている。本稿は米国環境政策ネットワーク調査を日韓の同調査と比較し、米国の特性を浮き彫りにする。これは広範な政策ネットワークの構造と機能を国際比較する白米独韓調査計画の中間報告である

Comparing serial X-ray crystallography and microcrystal electron diffraction (MicroED) as methods for routine structure determination from small macromolecular crystals.

Innovative new crystallographic methods are facilitating structural studies from ever smaller crystals of biological macromolecules. In particular, serial X-ray crystallography and microcrystal electron diffraction (MicroED) have emerged as useful methods for obtaining structural information from crystals on the nanometre to micrometre scale. Despite the utility of these methods, their implementation can often be difficult, as they present many challenges that are not encountered in traditional macromolecular crystallography experiments. Here, XFEL serial crystallography experiments and MicroED experiments using batch-grown microcrystals of the enzyme cyclophilin A are described. The results provide a roadmap for researchers hoping to design macromolecular microcrystallography experiments, and they highlight the strengths and weaknesses of the two methods. Specifically, we focus on how the different physical conditions imposed by the sample-preparation and delivery methods required for each type of experiment affect the crystal structure of the enzyme

Mapping protein dynamics at high spatial resolution with temperature-jump X-ray crystallography

温度による酵素の構造変化を分子動画撮影 様々な生体高分子のダイナミクスを決定する新たな方法論. 京都大学プレスリリース. 2023-09-19.Understanding and controlling protein motion at atomic resolution is a hallmark challenge for structural biologists and protein engineers because conformational dynamics are essential for complex functions such as enzyme catalysis and allosteric regulation. Time-resolved crystallography offers a window into protein motions, yet without a universal perturbation to initiate conformational changes the method has been limited in scope. Here we couple a solvent-based temperature jump with time-resolved crystallography to visualize structural motions in lysozyme, a dynamic enzyme. We observed widespread atomic vibrations on the nanosecond timescale, which evolve on the submillisecond timescale into localized structural fluctuations that are coupled to the active site. An orthogonal perturbation to the enzyme, inhibitor binding, altered these dynamics by blocking key motions that allow energy to dissipate from vibrations into functional movements linked to the catalytic cycle. Because temperature jump is a universal method for perturbing molecular motion, the method demonstrated here is broadly applicable for studying protein dynamics