Fish disease control in Japan

The regulatory authority responsible for the control of aquatic animal diseases in Japan is the Animal Products Safety Division, Food Safety and Consumer Affairs Bureau, Ministry of Agriculture, Forestry, and Fisheries (MAFF). The ministry (Animal Products Safety Division) specifies certain diseases and their host species that are subjects for import quarantine on the basis of the law called Fisheries Resources Protection Act. The MAFF also implements risk control measures for the same diseases within Japan on the basis of another law, Fish Farming Production Maintaining Act. Currently, 24 such diseases are listed. For disease control within Japan, the MAFF issues Guideline for the Control of Aquatic Animal Diseases, which states the roles of different stakeholders, appropriate actions that are to be taken on the occurrences of specified or other diseases, fish health guidelines for fish farmers, or diagnostic methods for specified diseases, etc. Local prefectural governments in Japan are required to place personnel who work on fish health issues at the prefectural fisheries research laboratories. These people usually inspect fish farms, observe cultured aquatic animals, supervise the use of antibiotics or vaccines, and guide fish farmers for disease control. Disease diagnosis for aquatic animals is usually conducted by these local fisheries research labs for free. The Japan Fisheries Resource Conservation Association provides a comprehensive training course on fish diseases including laws or hands-on trainings for the staff of prefectural fisheries research laboratories. The JFRCA also give local fish health personnel the qualification as the fish health expert, if the person passes the examination conducted after the training course. Primary diagnosis for specified diseases is conducted by local fisheries laboratories. On the occurrence of the diseases that are suspected to be one of the specified diseases or OIE listed diseases that have not been reported in Japan, the samples are sent to the National Research Institute of Aquaculture (NRIA) where confirmatory diagnosis is made. When such diseases are confirmed, it is reported to the MAFF (or to the OIE through MAFF). For specified diseases, Fish Farming Production Maintaining Act enables local governments to implement necessary measures to prevent the disease from spreading, including issuing orders such as to stop the transfer of the animals to other watersheds, to destroy animals, or to disinfect the facilities. When an unknown disease is encountered by a prefectural fisheries research laboratory, the NRIA is requested to conduct diagnosis. The NRIA develops diagnostic methods for new diseases and disseminate the techniques to local fisheries research laboratories. The NRIA provide positive control materials for disease diagnosis, hands-on trainings of specific subjects concerning diagnostic techniques, or proficiency tests for the fish health personnel of the local fisheries research laboratories

The Effects of Class Origin on Dropout from Higher Education in Postwar Japan

The purpose of this article is to explore the relationship between dropout from higher education and social class origin. It focuses on the following three points; 1) to investigate the pattern of association between class origin and the risk of dropout; 2) to compare the impact of class origin on dropout among several educational transition stages; 3) to examine the trends in the effect of class origin on dropout from higher education. In order to conduct the empirical analysis, large-scale datasets which were merged from various Japanese national representative survey datasets, such as the Social Stratification and Mobility surveys (SSM), Japanese General Social Surveys (JGSS), and Japanese Life-course Panel Surveys (JLPS) are used. The risk of dropout is estimated using binary logit models, rare-event logit models, and transition models. Results show that the risk of dropout from higher education is affected by class origin. Non-manual and agricultural classes are less likely to drop out, while manual and self-employed classes are more likely to drop out from higher education. As for dropout from secondary education, the same pattern of inequality of the risk of dropout among classes is observed. The degree of impact of class origin on dropout is smaller than that on entering into next stage of education. There are no trends in the effects of class origin on dropout. This finding supports Maximum Maintained Inequality (MMI) hypothesis because educational expansion did not affect the pattern of educational inequality including dropping out stage. In conclusion, stable, huge inequality of dropout among social classes is found. Class origin is crucial factor for predicting the risk of dropout from higher education, also a long time ago even now.本研究は，科学研究費・特別推進研究（25000001）および基盤研究C（16K04029），2016年度参加者公募型共同研究（二次分析研究会テーマB）の成果の一部である

Expression patterns of gdnf and gfrα1 in rainbow trout testis.

In mice, glial cell line-derived neurotrophic factor (GDNF) is essential for normal spermatogenesis and in vitro culture of spermatogonial stem cells. In murine testes, GDNF acts as paracrine factor; Setoli cells secrete it to a subset of spermatogonial cells expressing its receptor, GDNF family receptor α1 (GFRα1). However, in fish, it is unclear what types of cells express gdnf and gfrα1. In this study, we isolated the rainbow trout orthologues of these genes and analyzed their expression patterns during spermatogenesis. In rainbow trout testes, gdnf and gfrα1 were expressed in almost all type A spermatogonia (ASG). Noticeably, unlike in mice, the expression of gdnf was not observed in Sertoli cells in rainbow trout. During spermatogenesis, the expression levels of these genes changed synchronously; gdnf and gfrα1 showed high expression in ASG and decreased dramatically in subsequent developmental stages. These results suggested that GDNF most likely acts as an autocrine factor in rainbow trout testes

Variation of Rumen Bacterial Diversity in Steers after the Beginning of Grazing

Holstein heifers before or after puberty often are herded on public pastures in Japan. The herbage intake and rumen fermentation of grazing heifers that are not adapted for fresh herbage decreases due to a change of feed from stall-fed dried forage to fresh herbage. This limits their performance during the first several weeks on pasture. Thus, the feeding program such as supplementation before and after the beginning of grazing is important. An increase in ammonia concentration and a decline in fibre degradation in the rumen of a heifer (both of which occur simultaneously with low herbage intake and rumen fermentation) would be caused by the reduced capacity of various bacteria to produce peptides and degrade fibre (Oshio and Tahata 1981). This suggests that variation in rumen bacterial diversity plays an important role in herbage intake and rumen fermentation. However, less information is available on how bacterial diversity in heifers varies during the first few weeks of grazing. This information will provide the basis for designing nutritional management programs for heifers before and after the beginning of grazing. The objective of this study was to determine how herbage intake, digestibility, and rumen bacterial diversity vary in steers that have started grazing without adaptation for fresh herbage during the first 4 weeks after the beginning of grazing

Effects of dietary inulin, statin, and their co-treatment on hyperlipidemia, hepatic steatosis and changes in drug-metabolizing enzymes in rats fed a high-fat and high-sucrose diet

<p>Abstract</p> <p>Background</p> <p>Rats fed a high-fat and high-sucrose (HF) diet develop hepatic steatosis and hyperlipidemia. There are several reports that a change in nutritional status affects hepatic levels of drug-metabolizing enzymes. Synthetic inulin is a dietary component that completely evades glucide digestion. Supplementing a HF diet with inulin ameliorates hypertriglycemia and hepatic steatosis, but not hypercholesterolemia. This study aimed at distinguishing the effects of synthetic inulin and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin), which inhibit cholesterol biosynthesis.</p> <p>Methods</p> <p>We examined effects of co-treatment with synthetic inulin (5%) and fluvastatin (0, 4, and 8 mg/kg, <it>per os</it>) on body weight, epidydimal white adipose tissue weight, serum and hepatic lipid profiles, and hepatic cytochrome P450 (CYP) mRNA and protein profiles in rats fed a standard diet or a HF diet for 3 weeks.</p> <p>Results</p> <p>Treatment with the synthetic inulin (5%) or fluvastatin at 4 mg/kg (lethal dose in rats fed the HF diet, 8 mg/kg) ameliorated the elevation in hepatic triacylglycerol and total cholesterol levels in rats fed the HF diet. Whereas co-treatment with the inulin (5%) and fluvastatin (4 mg/kg) had a tendency to more strongly suppress the elevation in serum levels of very low density lipoprotein triacylglycerol than either treatment alone, no additive or synergistic effect was found in decrease in hepatic lipid levels. Hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein and methoxyresorufin <it>O</it>-demethylase and ethoxyresorufin <it>O</it>-deethylase activities were reduced in rats fed the HF diet. The synthetic inulin alleviated the reduction in hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein more strongly than fluvastatin, and no synergistic effects were observed on co-treatment. Furthermore, hepatic levels of aryl hydrocarbon receptor mRNA were decreased in rats fed the HF diet and recovered to near normal values with the intake of dietary inulin, which correlated with change in CYP1A1/2.</p> <p>Conclusions</p> <p>Dietary inulin alone was effective to prevent the development of hepatic steatosis, ameliorate nutritional effects, and alleviate the hepatic change in the expression of CYP1A1/2 and CYP2E1, while co-treatment with statin did not have additive or synergistic effects and statin may cause adverse effects in rats fed the HF diet.</p

Fracture origin and crack propagation of CAD/CAM composite crowns by combining of in vitro and in silico approaches

Purpose: Fractographic analysis has been used to investigate the fracture behavior of Computer-aided design/computer-aided manufacturing (CAD/CAM) composite crowns by subjecting them to compression tests. However, it is difficult to investigate details of the fracture, including its initiation and propagation, using in vitro tests. The aim of this study was to determine the fracture origins and the order of crack initiation of CAD/CAM composite crowns using in silico nonlinear dynamic finite element analysis (FEA). Material and methods: The following materials were used: Cerasmart (CS), Katana Avencia Block (KA), and Shofu Block HC (HC) as CAD/CAM crowns, Panavia SA Cement Plus (SA) as a luting material, and Clearfil DC Core Plus (DC) as an abutment. The elastic moduli and fracture strain of each material were obtained from the stress–strain curve of in vitro three-point bending tests. The fracture origins and order of crack initiation of the materials were determined by in silico nonlinear dynamic compression analysis. Load-displacement curves were statistically compared with the results of the in vitro compression tests (Pearson's correlation test, α = 0.05). Results: The nonlinear dynamic FEA demonstrated that crack initiation was primarily observed near the lingual side of the CAD/CAM crowns and immediately propagated to the central fossa. The models were fractured following the in vitro fracture strains, showing the same order for the products tested (CS/KA/HC, SA, and DC). Load-displacement curves with the use of CS, KA, and HC were significantly correlated to the corresponding in vitro compression tests results (CS: r = 0.985, p < 0.05, KA: r = 0.987, p < 0.05, and HC: r = 0.997, p < 0.05). Conclusions: The in silico model established in this study clarified the crack initiation of the CAD/CAM composite crowns and the order of crack initiation among the investigated products, suggesting that the present approach is useful for analyzing the fracture behavior of CAD/CAM composite crowns in detail.Yamaguchi S., Katsumoto Y., Hayashi K., et al. Fracture origin and crack propagation of CAD/CAM composite crowns by combining of in vitro and in silico approaches. Journal of the Mechanical Behavior of Biomedical Materials 112, 104083 (2020); https://doi.org/10.1016/j.jmbbm.2020.104083

オゾン水中におけるゴム材料の劣化挙動解析

目次 第1章 序論 第2章 オゾン水中におけるEPDMの劣化現象 第3章 オゾン水中におけるEPDMの劣化反応機構 第4章 オゾン水中の残留塩素、EDPM に配合したフィラーが劣化挙動に及ぼす影響 第5章 オゾン水中におけるフッ素ゴムの耐久性評価 第6章 総括Submitted by アルバイト QIR ([email protected]) on 2013-06-18T01:20:37Z No. of bitstreams: 2 ams4.pdf: 3011965 bytes, checksum: 6d73a892ef768aaa7d25c3921a341160 (MD5) ams4_abstract.pdf: 101129 bytes, checksum: 6393cc1e8512d6f94bebfb15eaf1c0c1 (MD5)Made available in DSpace on 2013-06-18T01:20:37Z (GMT). No. of bitstreams: 2 ams4.pdf: 3011965 bytes, checksum: 6d73a892ef768aaa7d25c3921a341160 (MD5) ams4_abstract.pdf: 101129 bytes, checksum: 6393cc1e8512d6f94bebfb15eaf1c0c1 (MD5) Previous issue date: 2012-03-27主1-参1統合新領域_オートモーティブサイエンス_先端材料水中のオゾンは非常に高い酸化力を有し、反応、分解後は無害な酸素や水へと変化し、残留性も低い。これらの利点のため、有機物の除去を目的とした下水、浄水処理等の分野においてオゾンの利用が増加している。一方で、オゾンの溶解した水、いわゆるオゾン水中でゴム材料を使用した際に、劣化に伴う不具合が生じる事例が発生しつつある。気相ではオゾンに対し高い耐性を有するエチレンプロピレンジエンゴム（EPDM）が、水相ではオゾンにより損傷を受けやすいという、既存の概念とは反した現象が認められる。現状において、オゾン水中におけるゴム材料の劣化現象の特徴、反応機構は不明瞭である。本論文では水道用ゴムとして多用されるEPDMと、化学的安定なフッ素ゴムの一種であるポリ（フッ化ビニリデン-ヘキサフルオロプロピレン-テトラフルオロエチレン）（FKM）のオゾン水中における劣化挙動を解析した。オゾン水処理後のEPDM表面には粘着力を有する液状物質が出現した。このEPDM表面の粘着性物質は、EPDM分子鎖の酸化劣化により低分子量化した物質に由来することをフーリエ変換赤外分光（FT-IR）法、サイズ排除クロマトグラフィー（SEC）を用いたキャラクタリゼーション結果から明確にした。さらに、表面近傍に生成した劣化物がオゾン水中へ徐々に溶出するとともに、EPDMの重量が減少した。EPDM表面が激しく損傷した原因の一つとして、表面の親水化及び低分子量化が進行したことにより、オゾン水が試料内部へ深く浸透することを容易にしたためと考えられた。また、水中におけるオゾンの自己分解反応の過程で生成するヒドロキシルラジカル（•OH）がEPDMの劣化因子として作用することを、オゾン分解速度とEPDMの劣化速度の関係及び処理後表面の官能基を帰属した結果より結論付けた。さらに、核磁気共鳴法により特定した劣化生成物の化学構造から、オゾン水中のEPDMの劣化は、オゾンとの直接酸化反応以外に、•OHによる主鎖のC-H結合の水素引き抜き反応を起点とした主鎖分解を伴う自動酸化反応が寄与していると推察された。水道水を原料とするオゾン水使用環境を想定し、残留塩素の共存するオゾン水中でEPDMを処理した結果、EPDM表面はオゾン水中と同様にマクロな損傷を発現した。ただし、残留塩素の共存するオゾン水中では、オゾン水単独で処理した場合に比べて、表面近傍の分子鎖切断がより進行していた。この理由として、EPDM表面近傍が親水化され、酸化力を有する残留塩素がEPDM試料内部に浸透しやすくなったこと、分子鎖がラジカル等の活性化状態に誘起され、酸化力の弱い塩素との反応も生じやすくなったことが原因として推察された。したがって、水道水を原料とするオゾン水中でゴム材料を使用する場合、オゾンだけでなく残留塩素の存在も考慮する必要がある。ゴムの一般的な補強剤であるカーボンブラックまたはシリカを配合したEPDMをオゾン水中で処理した結果、カーボンブラック配合EPDMの劣化による損傷は、シリカ配合EPDMより著しかった。この損傷度合いの差異には、カーボンブラックとシリカの性質が寄与していることが判明した。また、実際の使用状況に即した条件として、オゾン水中に残留塩素を含む場合も検討した結果、やはりEPDMに含まれる補強剤の差異により、劣化挙動が大きく異なっていた。これらの結果は、ゴム材料に配合された無機充てん材の性質が、そのゴム材料のオゾン水中における劣化挙動に強く影響を及ぼすことを示唆した。オゾン水処理後のFKMは、EPDMとは異なり、マクロな表面形態変化は認められなかった。また、FT-IR法やSECによる分析結果より、主鎖構造の変化は認められなかった。これは主鎖中のC-F結合が極めて安定であることや、フッ素原子の嵩高さや電気陰性度により、C-H結合に対するオゾンや•OHとの反応が生じにくかったと考えられた。一方で、オゾン水処理後FKM表面近傍の力学特性がわずかに変化した。これは、FKMの架橋点として導入した構造がオゾン水処理により劣化したことにより、表面近傍の架橋密度の低下を引き起こしたことが起因していた。本論文で得た知見は、オゾン水中におけるゴム材料の劣化挙動の基礎情報となるものであり、様々なゴム材料のオゾン水に対する耐久性評価、劣化調査において活用が期待される

Pourines. XLV. : Syntheses and Cytokinin Activities of the Cis Isomers of (1\u27R)-1\u27-Methylzeatin and Its 9-β-D-Ribofuranoside

(1\u27R)-1\u27-Methyl-cis-zeatin (2b) and its 9-β-D-ribofuranoside (4b) have been synthesized for the first time from D-alanine (5) in 7 steps. The new cis-zeatin derivatives 2b and 4b, together with known cis-zeatin (2a), were tested for cytokinin activity in the tobacco callus and the lettuce seed germination bioassays. In both bioassays, the cytokinin activity was found to follow the order 2a>2b>4b, indicating that 2b and 4b were less active than the corresponding trans isomers 1b and 3b (natural cytokinins from Pseudomonas syringae pv savastanoi), respectively