journal article

Context: Ethanolamine plasmalogens (EPls) and choline plasmalogens (CPls) are classes of ethanolamine ether phospholipids (ePE) or choline ether phospholipids (ePC), respectively. EPls play crucial roles in maternal and breastfed infant bodies and stimulate gonadotropin secretion by gonadotrophs. Aims: To estimate changes in and importance of plasma concentrations of EPls and CPls, utilizing newly developed enzymatic fluorometric assays for ePE and ePC in postpartum Holstein cows. Methods: Plasma samples were collected 3 weeks before expected parturition until approximately 8 weeks after parturition (16 primiparous and 38 multiparous cows) for analysis. Key results: Plasma concentrations of ePE and ePC, most of which are plasmalogens, declined before and increased after parturition and stabilised near the day of the first postpartum ovulation (1stOV). From weeks 2 to 3 after parturition, third-parity cows exhibited ePE concentrations that were higher than those of other parity cows. The days from parturition to 1stOV correlated with days from parturition to conception. On the day of 1stOV, milk yield correlated with plasma concentration of both ePE and ePC, while ePC concentration correlated negatively with milk fat percentage. At the early luteal phase after 1stOV, plasma ePE concentration correlated with plasma anti-Müllerian hormone concentration (r = 0.39, P < 0.01), and plasma ePC concentration correlated with plasma follicle-stimulating hormone concentration (r = 0.43, P < 0.01). Conclusion: The concentrations of ePE and ePC changed dramatically around parturition and 1stOV, and then the concentrations correlated with the important parameters. Implications: The blood plasmalogen may play important roles in postpartum dairy cows.

China has been struggling with waste classification for decades, even after the mandatory implementation of relevant policy in 2017. However, the causes of the failing performance of waste classification in developing countries attract little scholarly attention. A recent literature review also identified a failure to classify waste in developing countries, noting that its causes have attracted little scholarly interest. In this paper, we would like to examine the current situation and issues of policies for classifying household waste in China's urban sector. In this paper, we conducted a questionnaire survey of residents in Changsha City, Hunan Province, examined their awareness of waste classification, classifying behavior, and their awareness of paying for waste reduction, elucidated the factors that affect them, and estimated the amount of willing to pay (WTP) for waste reduction. In this paper, endogenous factors are more significant influencing behaviors than exogenous factors.

Since its inception, analytic philosophy has failed to attain dominance in Japan. However, the 21st century has seen analytic philosophy gain traction among Japanese philosophers. This paper, which examines the status quo of analytic philosophy in Japan since 2000, consists of two parts. The first part deals primarily with organizations—specifically, relevant associations, journals, conferences, universities, and publishers are illustrated. The second part explores key works in each area—namely, philosophy of science, philosophy of language, philosophy of logic and mathematics, philosophy of mind, and metaphysics. Key works in other areas are also briefly addressed.

McTaggart’s paradox and his A-theory and B-theory are basic notions in the contemporary philosophy of time. It is well known that the paradox was introduced by McTaggart’s paper called “The Unreality of Time” published in 1908, so that it has a one-hundred-year history. As for A-theory and B-theory, in contrast, McTaggart himself didn’t consider both of them at all. The notions of A-theory and B-theory came much later, 60 years after the paradox. Moreover, they had not been as popularized as they are today until quite recently, at least after the 1990s. This paper aims to trace the origin of the notions of A-theory and B-theory and show how the debates behind them, especially objections to “spatialising time,” form the notions.

Imitation is simple behavior which uses successful actions of others in order to deal with one’s own problems. Because success of imitation generally depends on whether profit of an imitating agent coincides with those of other agents or not, game theory is suitable for specifying situations where imitation can be successful. One of the concepts describing successfulness of imitation in repeated two-player symmetric games is unbeatability. For infinitely repeated two-player symmetric games, a necessary and sufficient condition for some imitation strategy to be unbeatable was specified. However, situations where imitation can be unbeatable in multi-player games are still not clear. In order to analyze successfulness of imitation in multi-player situations, here we introduce a class of totally symmetric games called unexploitable games, which is a natural extension of two-player symmetric games without exploitation cycles. We then prove that, for infinitely repeated unexploitable games, there exist unbeatable imitation strategies. Furthermore, we also prove that, for infinitely repeated non-trivial unexploitable games, there exist unbeatable zero-determinant strategies, which unilaterally enforce some relationships on payoffs of players. These claims are demonstrated in the public goods game, which is the simplest unexploitable game. These results show that there are situations where imitation is unbeatable even in multi-player games.

先行研究では、技能実習生に関する日本語教育の問題点の１つとして、講習で教えられている日本語が作業現場で使われている日本語と相違していると指摘されている。しかし、具体的にどのような点で相違しているのかということについては明らかにされていない。技能実習生が作業現場で日本人の同僚からの指示を理解するためには、日本語の統語構造の特徴から、文末表現を理解することが欠かせないと考えられる。日本語の文末表現には、「発話の機能」を明示的に示す働きがある。命令か依頼かが文末表現を聞いて初めてわかるからである。そこで、本稿は鉄骨工場のような指示が多い作業現場をフィールドとし、そこでの、技能実習生に向けられた日本語母語話者の発話における文末表現の特徴を明らかにした。そのうえで、そこで明らかになった特徴と技能実習生向けの講習用教材の比較を通し、両者の、文末表現上の相違点を析出することを試みた。研究結果として、１）作業現場の発話には、言いさしが半数近くあり、よく使われていると言えるのに対し、講習用教材では、言い切りが主導的な地位を占めていること、２）作業現場では、普通体を主基調として、発話が進められているのに対し、講習用教材では、丁寧体を主使用文体としていること、３）作業現場では、「動詞等の∅形」の使用率は３分の１に足りないのに対し、講習用教材では「動詞等の∅形」の使用率は半数近くあること、４）作業現場では、相応の縮約形があるものについては、縮約形を使うのが一般的であるのに対し、講習用教材では、ほとんどの場合に、相応の縮約形があったとしても、元の形そのままで使われていることが明らかになった。このような状況を踏まえ、今後、講習において、作業現場で働く日本語母語話者の発話の文末表現をどのように導入し、教えたらいいのかについて、工夫が必要であると思われる。

Zero-determinant strategies are memory-one strategies in repeated　games which unilaterally enforce linear relations between expected payoffs of　players. Recently, the concept of zero-determinant strategies was extended　to　the class of memory-n strategies with n _ 1, which enables more compli-cated control of payoffs by one player. However, what we can do by　memory-n　zero-determinant strategies is still not clear. Here, we show that memory-n　zero-determinant strategies in repeated games can be used to control condi-tional expectations of payoffs. Equivalently, they can be used to control ex-pected payoffs in biased ensembles, where a history of action pro_les with large　value of bias function is more weighted. Controlling conditional expectations　of payoffs is useful for strengthening zero-determinant strategies, because play-ers can choose conditions in such a way that only unfavorable action pro_les　to one player are contained in the conditions. We provide several examples　of memory-n zero-determinant strategies in the repeated prisoner's dilemma　game. We also explain that a deformed version of zero-determinant strategies　is easily extended to the memory-n case.

ECRスパッタ法によりCo-Cr膜を作成したとき、その磁気特性と結晶学的特性は成膜中の基板を照射するイオン加速電圧に強く依存することか明らかとなった。このイオン加速電圧はArガス圧とターゲット-基板間距離により制御することができ、イオン加速電圧を20V以下に適正化した結果、50nmの厚さのCo-Cr膜で、優れた結晶配向性(5゜以下のΔθ_<50>)、高い垂直異方性磁界(4kOe以上のH_k)、高い垂直方向力(1400Oe以上のH_<c⊥>)が得ることができた。

誘導結合型プラズマ(ICP)を利用したマグネトロンスパッタ装置を試作し、Co-Cr垂直磁気異方性膜の作製を行った。誘導結合型プラズマ支援マグネトロンスパッタ装置では、高周波によるプラズマ生成と、ターゲットに印可した直流によるスパッタ成膜とが機能分離できているために、通常のマグネトロンスパッタ法ではプラズマの維持が不可能な低いターゲット電圧領域においてもCo-Cr薄膜の作成が可能なことが明らかになった。ICPを用いることで、通常のマグネトロンスパッタ法のみの場合よりも、高い成膜速度が実現できた。ICP電力を増すと、作製したCo-Cr膜の垂直磁気異方性は減少する傾向がみられた。大きな垂直磁気異方性をもつCo-Cr膜を高速に作製するには、ICPを用いることに加えて、正の基板バイアス電圧の印可を併用することが効果的であるとの見通しを得た。

電子サイクロトロン共鳴マイクロ波プラズマを利用したスパッタ成膜装置(ECRスパッタ装置)において、独自のパラメータであるマイクロ波電力に着目し、これを活用してCo-Cr-Ta/Ti垂直磁気ディスクの高性能化を試みた。プラズマ生成室に投入するマイクロ波電力を増加させると、生成されるプラズマ密度が増加し、成膜速度を高まること、成膜中に基板を照射するArイオンの量が増加することが明らかになった。Co-Cr-Ta膜の作製において、マイクロ波パワーを成膜初期には高パワーとし、途中からは低パワーに変更するという制御を行うことによって、グレインが微細で、磁気特性および記録特性に優れた垂直磁気ディスクをパワー一定とした従来よりも高速に作製できることを見出した。

Decomposition of organic nitrogenous materials in soil was affected by C/N ratio.Immobilization of nitrogen mineralized from nitrogenous material added to the soil was influenced by the degradability of carbonaceous and nitrogenous materials.The turnover of nitrogen which had been freshly immobilized in the presence of glucose in the soil was faster than that immobilized with cellulose or lignin. The effect of soil-drying on the mineralization of organic nitrogen immobilized through the decomposition of carbonaceous and nitrogenous materials in the soil depended significantly on the availability of carbonaceous materials as a microbial energy source.However, the drying effect was not always proportional to the amount of organic nitrogen accumulated in the soil.

Phenolic compounds in the soils collected from plow layers of greenhouse and field cultures were surveyed quantitatively by gas chromatography. The results are as follows : 1) p-Coumaric, ferulic, salicylic, p-hydroxybenzoic, vanillic, syringic, and protocatechuic acids were detected in all upland soils, as in the case of paddy and forest soils reported previously. Among these phenolics, p-coumaric acid was present in the largest quantity in most of the upland soils up to 29.0 ppm. 2) The total amounts of individual phenolic acids in the upland soils ranged from 9.5 to 62.0 ppm (average 26.0 ppm). Also, the amounts were less than 0.18% (average 0.10%) of the total soil organic matter. The average values in the upland soils were higher than those in the paddy soils, but were lower than those in the forest soils. 3) In upland soils, the concentrations of p-hydroxybenzoic, vanillic, syringic, p-coumaric, and ferulic acids, which have no chelating ability, were considerably related to the carbon content of soil, but the concentrations of protocatechuic and salicylic acids, which are chelating agents, were not related to that of soil. These relationships agreed with those found in paddy and forest soils.

反応性ECRスパッタ法を用いることにより、3000 Oe程度の高い垂直方向抗磁力と、垂直磁気異方性を示すCo含有酸化鉄薄膜メディアを、室温から150℃の低温で作製できる。このメディアの熱緩和特性、記録特性および再生電圧の時間変化について調べた。その結果、作製したCo含有酸化鉄薄膜メディアは、市販のMPテープと同等の良好な熱安定性を有し、20 Gb/in^2級長手ハードディスクと同程度のD_<50>および高記録密度領域での信号の時間減衰を示すことが明らかとなった。

反応性ECRスパッタ法を用いて150℃の基板温度で作製したCo含有酸化鉄薄膜メディアを、2種類の方法によって酸化処理を行い、その磁気特性および記録特性におよぼす効果について調べた。その結果、ECRプラズマを照射することによって酸化処理を施したCo含有酸化鉄薄膜メディアは、平滑な表面を維持したまま磁気特性を向上させることができ、MIGヘッドによる記録・再生において市販の20Gb/in^2級長手ハードディスクと同程度のD_<50>を示すことがわかった。

放電プラズマ焼結法(SPS)を用いて、厚みがサブmm～μm領域のNi-Zn-Cuフェライト焼結体およびサブmm厚のBaフェライト焼結体の作製を試みた。SPS法では、緻密な焼結体を従来の焼結法よりも大幅に短い時間(数分程度)で製造できた。Ni-Zn-Cuフェライト焼結体については、10μmまで厚みを薄くした場合においても良好な軟磁気特性(保磁力4.8 0e)が得られた。Baフェライト焼結体については、粒径が均一な焼結体が得られ、厚みを0.5mm程度まで薄くしても良好な磁気特性(保磁力2.1 k0e)が得られた。