Predominant accumulation of a 3-hydroxy-γ-decalactone in the male rectal gland complex of the Japanese orange fly, Bactrocera tsuneonis

The Japanese orange fly, Bactrocera tsuneonis, infests various citrus crops. While male pheromone components accumulated in the rectal glands are well characterized for Bactrocera, but information regarding the chemical factors involved in the life cycles of B. tsuneonis remains scarce. Herein, several volatile chemicals including a γ-decalactone, (3R, 4R)-3-hydroxy-4-decanolide [(3R, 4R)-HD], were identified as major components, along with acetamide and spiroketals as minor components in the rectal gland complexes of male B. tsuneonis flies. The lactone (3R, 4R)-HD was also identified in female rectal gland complexes. The amount of this compound in mature males was significantly higher than those observed in females and immature males. The lactone (3R, 4R)-HD was detected in flies fed with sucrose only, indicating that this lactone is not derived from dietary sources during adulthood, but biosynthesized in vivo. The predominant accumulation of (3R, 4R)-HD in mature males also suggests a possible role in reproductive behavior

Completion of the first ITER toroidal field coil structure

本論文は、日本が100%調達責任を有するITERのトロイダルコイル構造物の第1号機の完成を報告するものである。主な技術的な課題は、(i)極低温(4K)でも高い延性を持つ新規材料の開発、(ii)部分溶け込み溶接の適用、(iii)溶接変形対応、(iv)オーステナイトステンレス鋼溶接部の減衰効果を加味した超音波探傷試験法の開発、(v)巨大で複雑なD形状構造物の封止溶接開先の0.5mmオーダー公差での開先合わせ、などである。これらの各技術課題を解決し、ITER　TFコイル構造物第1号機は成功裏に完成することができた

Results of All ITER TF Full-Size Joint Sample Tests in Japan

Nine toroidal field (TF) coils have been developed in Japan for the international thermonuclear experimental reactor (ITER). The joint resistance of TF coil should satisfy the requirement of smaller than 3 nano-ohm at 2 T of external magnetic field and 68 kA of transport current. Full-size joint sample (FSJS) tests were performed for joint development and for TF coil manufacture, as part of the process control. 11 FSJS tests are conducted in total. FSJS tests were conducted with assistance from a test faculty in the National Institute for Fusion Science as reported in a previous paper. All FSJS tests successfully satisfied the requirement of resistance less than 3 nΩ at 2 T. Additionally, the TF coil joints are subjected to cyclic electromagnetic force and warm-up/cool-down during the ITER operation. The authors investigated the joint performance for the abovementioned influence. The results showed no degradation in the joint resistance. Thus, the TF joint developed in Japan was qualified successfully

Floral synomone diversification of sibling Bulbophyllum species (Orchidaceae) in attracting fruit fly pollinators

Floral scent is one of the crucial cues to attract specific groups of insect pollinators in angiosperms. We examined the semiochemical diversity in the interactions between “fruit fly orchids” and their pollinator fruit fly species in two genera, Bactrocera and Zeugodacus (Tephritidae: Diptera). Two known attractants for the Dacini fruit flies, methyl eugenol (ME) and raspberry ketone (RK), have been identified from the Bulbophyllum orchids. Additionally, zingerone (ZN), with a hybrid chemical structure between ME and RK, and attracts both ME- and RK-sensitive fly species, was also identified. Male flies utilize the floral scent as sex pheromone precursor or components to attract conspecific females and gain mating advantage. We analyzed the floral components of two sibling orchids, Bulbophyllum macranthum collected from Southeast-Asian countries and Bu. praetervisum collected from Sabah, Malaysia. For Bu. macranthum, the major floral component from Malaysia and Thailand was identified as ZN; whereas that from the Philippines was ME. For Bu. praetervisum, RK was found as the major constituent, but chemical profiles of the attractants were different among individuals, i.e. in addition to RK, ZN was also found in some of the Bu. praetervisum flowers; and one of the specimens contained ME besides RK and ZN. These differences in fruit fly-attracting floral scents shown by the sympatric chemotypes of Bu. praetervisum are contrary to that shown by the allopatric chemotypes of Bu. macranthum, demonstrating the versatility in the floral synomone biosynthetic processes. Phylogenetic analysis using chloroplast DNA shows that the Malaysia- and Thailand-chemotypes of Bu. macranthum and Bu. praetervisum belong to the same lineage, although their chemical profiles are distinctly different. This demonstrates that diversification of floral synomone may happen even within a putative orchid species in order to attract a wider community of fruit fly pollinators from different genera to maximize pollination success

Evaluation of mass production results of cryogenic structural stainless steels for ITER toroidal field coils

The National Institutes for Quantum Science and Technology (QST) has been developing new cryogenic structural materials, such as JJ1 stainless, and nitrogen-enhanced 316L stainless, known as 316LN, since the 1980s for increased tensile strength to comply with the ITER requirements. QST has also developed prediction curves for yield stress and tensile strength at temperatures from room temperature to 4 K based on the actual properties of these materials at room temperature to reduce the number of tensile tests conducted at 4 K, which are costly. After material trials and qualifications, the manufacture of material candidates began in earnest from 2012. In total, over 2400 materials (over 5000 tonne) were manufactured by six fabricators until manufacturing was completed successfully in 2020. The material properties of each material candidate were evaluated by QST and added into a database registry. Sampling tests, e.g., tensile tests were conducted at 4 K and 77 K. The correlations between the mechanical and material properties were evaluated to optimize material specifications of future superconducting magnets. The accuracy of QST\u27s prediction curves was also confirmed. This paper summarizes the evaluation of the material properties and the prediction accuracy of mass-produced materials for the ITER toroidal field coil cases