Substrate-induced acceleration of N-ethylmaleimide reaction with the Cys-65 mutant of the transposon Tn 10-encoded metal-tetracycline/H+ antiporter depends on the interaction of Asp-66 with the substrate

AbstractWe previously reported that the reaction of [14C]N-ethylmaleimide (NEM) with the S65C mutant of the transposon Tn10-encoded metal-tetracycline/H+ antiporter (TetA(B)) is competitively inhibited by tetracycline [Yamaguchi, A. et al., FEBS Lett. 322 (1993) 201–204]. However, this observation has been revealed to be a mistake. The reaction of [14C]NEM with S65C TetA(B) was significantly and reproducibly accelerated by tetracycline, i.e. not inhibited. When Asp-66 was replaced by Ala, the reaction of NEM with the Cys-65 residue was no longer affected by tetracycline. In contrast, when Arg-70 was replaced by Ala, the acceleration of the reaction was unaltered. The tetracycline acceleration of the reaction to the Cys-65 residue was further stimulated with energization of the membrane on the addition of NADH. On the other hand, the tetracycline-induced acceleration was not observed in the absence of a divalent cation. These observations indicated that the Cys-65 locus is exposed to the medium according to the interaction of a divalent cationtetracycline chelation complex with Asp-66

和服構成における着装容姿についての考察

　和服の仕立て上がり寸法を決める割り出し法の有効性は、著者等のこれまでの一連の研究により確認している。なかでも標準体、ＪＩＳ規格によるＭサイズについては検討課題も皆無ではないにしろ、ほぼ良好との感触を得ている。　これまでＭサイズを対象とする時、当然のこととして腰囲と胸囲が相対的な数値の範囲、つまり腰囲・胸囲共にＭサイズの範囲内にあることを前提としていた。ところが、最近の若い女性は体格が向上し、腰囲に比較して胸が豊かな傾向がみられ、腰囲はＭサイズでも胸囲がＬサイズのタイプが少なくない。現に、本学服飾造形学科で開講している「和服構成演習」履修者に、そうした体型の学生が見受けられる。割り出し法は身体各部を計測して寸法を算出する方法であり、その際に算出の基準とするのは腰囲寸法であって胸囲は採寸対象箇所にすぎない。そうなると前述の体型の場合、着装時のスタイルを見ると下半身は形良く収まっていても胸元は不足気味になり衿の交差位置が下方になる。この現象は、胸囲の計測値が反映されないために胸幅が不足する事を示しており、融通性を特徴とする和服であり着裝不可能でないにしても、見た目或いは着心地を考慮すると改善の余地があると思われる。　そこで今回は、被験者として前述の服飾造形学科３年次の学生に協力を得て、胸幅に直接影響を及ぼすことが想定される「衽つけ線」を４種設定して試着衣を作製し実験を試みた。　結果として、多少の起伏はあっても、衿の交差位置は衽つけ線の移動により胸幅が広くなり上がっていく傾向にある。また、和服を着装する折りに、一般的に好ましいとされる着装ポイントの条件をほぼ満たしているのは、剣先位置を裾から真直ぐと設定したケースであることを把握した

Evolution of sex allocation in the genus Tetraneura (Aphididae: Pemphiginae).

Abstract: Sexuparae (autumnal migrants) of the Pemphiginae produce sexual males and females at once, and the sexuals mature without food intake. Hence, sex ratio and the size of sexuals are completely determined by the mothers (sexuparae). This study examined variation in sex ratio among species of Tetraneura and its allied genera. The relative size of sexuals to sexuparae (mothers) varied greatly among species. In species with relatively small sexuals, each sexupara produced both males and females; the number of males was constant and the number of females tended to increase in larger sexuparae. Sex allocation in these species can be explained by Yamaguchi (1985)’s model. In contrast, in species with relatively large sexuals, a considerable fraction of sexuparae produced sexual females alone. Rearing experiments in T.sp. O showed that sexuparae from one clone produced sexual females only, while those from other clones produced both males and females. In species with relatively large sexuals, the relative investment in both sexes was highly female-biased. Local mate competition has been assumed to be responsible for female-biased sex allocation. However, this comparative study suggests that sex allocation is also affected by the relative size of sexuals. The size of sexual females is highly correlated with that of first instar fundatrices (gall makers). Therefore, it is suggested that advantage of larger size in fundatrices, for example in fighting, has led to larger body size in sexual females and more highly female-biased sex allocation