PHOTOPROTECTIVE ACCLIMATION OF XANTHOPHYLL PIGMENTS TO HIGH LIGHT IN MARINE DIATOMS

創価大

Factors related to depression among childcare worker;Cross-sectional study in Hokkaido, Japan

The goal of the present study was to investigate the factors related to depression among childcare workers. From November 2015 to August 2016, 358 nurseries (17.9%) answered a questionnaire. Adjusted for nursery work experience totaling more than five years, work place, cooperation in the work place, quality of sleep, hospital visiting, factors related to work of more than five years (OR=0.55, 95%CIs=(0.34, 0.91)), ability to consult troubles with boss (OR=0.36, 5%CIs=(0.18, 0.73)), to be able to take paid holidays (OR=0.49, 95%CIs=(0.27, 0.88)), having a spouse (OR=0.55, 95%CIs=(0.32, 0.94)) were considered to decrease the risk of depression. The Japanese government should prompt to improve the reatment of nurseries

Crystallographic texture- and grain boundary density-independent improvement of corrosion resistance in austenitic 316L stainless steel fabricated via laser powder bed fusion

Improvement of corrosion resistance of austenitic 316L stainless steel via laser powder bed fusion (LPBF) is currently a prominent research topic; however, the effects of crystallographic texture and the related grain boundary density on the corrosion resistance of LPBF-fabricated parts have not been elucidated. For biomedical applications, crystallographic texture control from a single crystalline-like to randomly oriented polycrystalline microstructure is highly attractive for optimizing the mechanical properties (particularly the Young's modulus) of implants. An investigation of the impacts of crystallographic planes and grain boundaries exposed to the biological environment on corrosion behavior is necessary. 316L stainless steels with different crystallographic textures and grain boundary densities were successfully fabricated via LPBF. The corrosion resistances of the LPBF-fabricated specimens were comprehensively assessed by anodic polarization, dissolution, and crevice corrosion repassivation tests. The LPBF-fabricated specimens showed extremely high pitting potentials in the physiological saline compared with the commercially available counterparts, and importantly, excellent pitting corrosion resistance was observed irrespective of the crystallographic planes and grain boundary density exposed. Moreover, the LPBF-fabricated specimens did not show metastable pitting corrosion even in an accelerated test using an acid solution. The repassivation behavior of the specimens was not affected by LPBF. Such a drastic improvement in the corrosion resistances of the LPBF-fabricated specimens might be attributed to suppression of inclusion coarsening owing to the rapid cooling rate during solidification in LPBF. By using LPBF, the desired crystallographic texture can be introduced based on the desired mechanical properties without concern for corrosiveness.Tsutsumi Y., Ishimoto T., Oishi T., et al. Crystallographic texture- and grain boundary density-independent improvement of corrosion resistance in austenitic 316L stainless steel fabricated via laser powder bed fusion. Additive Manufacturing, 45, 102066. https://doi.org/10.1016/j.addma.2021.102066

Photoprotection and xanthophyll cycle activity of ice algae in Saroma-Ko Lagoon, Hokkaido, Japan

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月26日（月） 統計数理研究所 ３階セミナー

Spatial Variability in Biomass and Photosynthetic Characteristics of Bottom Ice Algae in Saroma-Ko Lagoon, Hokkaido

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月26日（月） 国立極地研究所 ３階ラウン

High intensity of light: a potential stimulus for maximizing biomass by inducing photosynthetic activity in marine microalga, Tetraselmis tetrathele

The current research aimed to increase biomass production by manipulating the light intensity between 300 and 2500 μmol m−2 s−1 into a semi-continuous culture system. The growth productivity, photosynthetic performance, pigments, lipids, and fatty acids compositions of Tetraselmis tetrathele were closely investigated. This microalga could tolerate high light intensity (1500 μmol m−2 s−1), where the light intensity per cell ranged 13 μmol m−2 s−1 g-dw−1 cell−1 produced 2.92–3.34 g-dw L−1 of dry-cell weight during steady-state growth condition, approximately 1.8 times higher than the condition at 300 μmol m−2 s−1. Interestingly, maximal electron transport rate of photosystem II (ETRmax) was induced to reflect the photoacclimation activity and accompanied with variations in pigments, lipids, and fatty acids profile to protect cells from photo-oxidative damage. The scavenging role of β-carotene as a vital photoprotective pigment was achieved upon exposure to excessive light, about 1.9-fold higher than 300 μmol m−2 s−1 light intensity

High productivity of eicosapentaenoic acid and fucoxanthin by a marine diatom chaetoceros gracilis in a semi-continuous culture

Significantly high eicosapentaenoic acid (EPA) and fucoxanthin contents with high production rate were achieved in semi continuous culture of marine diatom. Effects of dilution rate on the production of biomass and high value biocompounds such as EPA and fucoxanthin were evaluated in semi-continuous cultures of Chaetoceros gracilis under high light condition. Cellular dry weight increased at lower dilution rate and higher light intensity conditions, and cell size strongly affected EPA and fucoxanthin contents. The smaller microalgae cells showed significantly higher (p < 0.05) value of 17.1 mg g-dw−1 fucoxanthin and 41.5% EPA content per total fatty acid compared to those observed in the larger cells. Chaetoceros gracilis can accumulate relatively higher EPA and fucoxanthin than those reported previously. In addition, maintenance of small cell size by supplying sufficient nutrients and light energy can be the key for the increase production of valuable biocompounds in C. gracilis

Photophysiological characteristics of ice algal community in Saroma-ko Lagoon, Hokkaido ~Weak photoacclimation of ice algal community in 2009~

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月26日（月） 国立極地研究所 ３階ラウン

第6回「卒業生の保健師の集い」をふりかえって

報告Report第6回「卒業生の保健師の集い」の概要と振り返りを報告する。今回の「集い」でも、これまでと同様に卒後教育の側面を持つこと、参加者がエンパワメントされることが確認された。また、講演を県や市町村保健師にも公開し参加を得た事から、「集い」が地域への貢献の可能性をもつことが考えられた

南大洋インド洋区における植物プランクトン群集の光保護応答

第6回極域科学シンポジウム分野横断セッション：[IB1] 海氷域における生物地球化学的研究11月17日（火）　国立極地研究所１階交流アトリウ