Characteristics of Meteorological Conditions during a Severe Outbreak of Onion Downy Mildew and Metalaxyl Sensitivity of Peronospora destructor in Saga, Japan, in 2016

In 2016, an onion downy mildew epidemic caused by Peronospora destructor severely damaged the commercial onion fields in Saga Prefecture, western Japan. To identify the factors underlying the outbreak, we investigated the symptoms of downy mildew caused by secondary infections and examined P. destructor’s sensitivity to metalaxyl, the most effective traditional fungicide used against this onion pathogen, in 2016–2018. Disease symptoms developed in late March 2016, which was earlier than symptom development in 2017 and 2018. Furthermore, there were synchronous repeated disease development and favourable meteorological conditions for infection in early and late April resulting in the development of polycyclic epidemics. In field trials from 2016 to 2018, the efficacy of chlorothalonil + metalaxyl-M application ranged 18–45%, as calculated by comparing disease severity at the final stage of each treatment to that in the untreated plots. On the basis of the metalaxyl sensitivity observed in 2016, the effective concentration, which reduced germ-tube elongation in P. destructor by 50%, exceeded 200 µg ai/mL for certain strains. Our observations indicate that these characteristic meteorological conditions were major factors contributing to the severe disease outbreak in 2016. The emergence of less-metalaxyl-sensitive P. destructor strains may be an additional predisposing factor

Report of test on the deterioration of former geological hut at Syowa Station

In January 1957 the First Japanese Antarctic Research Expedition built a prefabricated living hut at Syowa Station, and this hut has been used as a laboratory for geological study, named Geology Hut. Because of aging of finishing and interior materials, the hut was dismantled in January 1981 and brought to Japan in April 1981. To investigate the deterioration of building materials, one floor panel and two wall panels were subjected to the following four tests and their strength was compared with the original strength : Bending test of panel; residual strength of adhesion used in wood lamination; strength test of panel core; test of heat conductivity and physical properties. Test results indicated no appreciable deterioration of building materials and these materials may still stand good for future use

High-Pressure Silicon Phase Created by High Power Ultrashort Laser Pulse at the Intensity of 1019W/cm2

Material states formed by high-power laser demonstrate new pathways for engineering polymorphs with novel optoelectronic properties. We present the observation of silicon phases only seen until now in laboratory experiments by ultrashort laser confined microexplosion.</p

キュウ チガク トウ タテモノ ノ セイノウ ヘンカ ニ カンスル シケン ホウコク

昭和32年1月, 第1次日本南極地域観測隊により昭和基地に建設された居住棟は, その後旧地学棟と改称され使用されてきたが, 仕上げ材の老朽化等から昭和56年1月, 第21次隊によって解体され, 同年4月日本に持ち帰えられた。この建物のうち, 床パネル1枚と壁パネル2枚を使って, 1) パネルの曲げ試験, 2) パネルの接着力試験, 3) パネル芯材の強度試験, 4) 断熱材の熱伝導率試験と物性測定, を行い, 南極における各種建築材料の経年変化を明らかにした。これらの試験の結果, 建物は25年を経過してもその性能にほとんど劣化は認められず, 将来にわたって十分使用に耐え得るものと判断した。In January 1957 the First Japanese Antarctic Research Expedition built a prefabricated living hut at Syowa Station, and this hut has been used as a laboratory for geological study, named Geology Hut. Because of aging of finishing and interior materials, the hut was dismantled in January 1981 and brought to Japan in April 1981. To investigate the deterioration of building materials, one floor panel and two wall panels were subjected to the following four tests and their strength was compared with the original strength : Bending test of panel; residual strength of adhesion used in wood lamination; strength test of panel core; test of heat conductivity and physical properties. Test results indicated no appreciable deterioration of building materials and these materials may still stand good for future use