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Yamaguchi journal of economics, business administrations & laws Volume 71 Issue 5-6 pp. 215 - 243
published_at 2023-03-31
Creators : Yanagida Takuji Publishers : The Economic Society of Yamaguchi University Updated At : 2023-06-20 13:45:26
Yamaguchi journal of economics, business administrations & laws Volume 71 Issue 5-6 pp. 199 - 214
published_at 2023-03-31
Creators : Tsunoda Yuka Publishers : The Economic Society of Yamaguchi University Updated At : 2023-06-20 13:39:10
Yamaguchi journal of economics, business administrations & laws Volume 71 Issue 5-6
published_at 2023-03-31
Publishers : The Economic Society of Yamaguchi University Updated At : 2023-06-20 13:30:44
目的:アルコール使用障害(Alcohol use disorder: AUD)は治療後も再発率が高く再発を予測する患者の要因は確立されていない。AUDでは衝動制御障害、実行機能障害および意思決定障害が報告されているため、本研究ではそれらを用いてAUDの予後予測因子を前方視的に明らかにすることを目的とした。 方法:20歳から70歳までの入院中のAUD患者41名を対象とした。入院中に、①情動顔go/no-go課題(衝動制御課題)および言語流暢性課題(実行機能課題)中の脳血流活性化の指標である酸素化ヘモグロビン積分値を機能的近赤外分光法(functional nearinfrared spectroscopy: fNIRS)を用いて測定し、さらに②不確実な状況下でのリスク選好課題(意思決定)を行った。退院後6ヶ月の再発の有無を主要アウトカムとした。 結果:退院後、24名(58.5%)が断酒を継続し、17名(41.5%)が再飲酒した。断酒群に比べて再飲酒群では、①情動顔go/no go課題における右前頭側頭領域の活性化が有意に低下し、②意思決定課題では有意にリスク追及的であった。断酒群でのみ、右前頭側頭領域の活性と渇望尺度の間に負の相関が観察された。さらに、退院後6ヶ月の飲酒の有無を従属変数とし、年齢、AUD重症度、発症年齢、右前頭葉領域の酸素化ヘモグロビン積分値及び意思決定課題でのリスク選好の5つの独立変数を用いた2項ロジスティック回帰分析を行い、各独立因子の再発への影響を検討した結果、右前頭側頭領域の酸素化ヘモグロビン積分値が小さいほど(オッズ比=0.161、p=0.013)、またリスク追及傾向が強いほど(オッズ比=7.04、p=0.033)再発リスクが増加することが示された。 結論:右前頭側頭領域の情動刺激に対する脳血流活性化の低下と、リスク追及傾向が、AUDにおける退院6か月後の再発を予測し得る可能性が示された。
Creators : 佐々木 順 Updated At : 2023-06-14 16:47:43
本論文は,申請者が山口大学大学院東アジア研究科在学中において進めてきた,遠隔教育支援環境における授業と学習活動の支援に関する研究をまとめたものである. 人口減少社会の到来により,特に地方において,適正規模での学校運営が難しい小規模の学校が増加傾向にある.小規模校では,きめ細やかな指導等が行える一方で,人間関係が固定化しがちであったり,多様な意見や考え方に触れることが少なくなったりなど,教育上の課題を抱えている.その解決策の1つとして,複数校の児童生徒が1つの学校に集まって合同授業が実施されているが,時間的・金銭的な問題などから実施回数が制限されるケースが多い.この合同授業を補う形で,日進月歩の勢いで進歩しているICT技術を活用した遠隔合同授業の取組みが期待され,教育実践が進められてきている. 一方,小学校や中学校だけでなく,大学などの高等教育機関においてもICTを活用した遠隔教育は進められてきている.さらに,新型コロナウィルス感染症のパンデミックを契機に,小学校・中学校・高校や高等教育機関だけでなく,塾など様々な場でオンライン授業あるいはオンライン学習といった遠隔教育の取り組みも行われてきている. しかしながら,オンライン授業や遠隔合同授業を実践する上では,環境整備面や授業実施面などで課題が存在する.特に,授業実施時における教員の作業負荷が非常に高いことが問題であり,オンライン授業や遠隔合同授業の特性や授業プロセスを踏まえた仕組みの構築や機能の開発が必要となる.さらに,オンライン授業や遠隔合同授業における学習者個人あるいはグループによる学習活動や,教員による教授活動や学習者グループの活動支援のプロセスを分析した上で,その状況に応じた支援手法を検討し,学習支援機能やその機能と連動した授業支援機能を遠隔教育支援ツール・アプリとして提供することが必要となる. そこで本研究では,高校・大学などにおけるオンライン授業や小学校・中学校の小規模校における遠隔合同授業といった遠隔教育を対象にして,校種やICT活用能力に応じた機能や画面に切り替えることができる設計思想を持った,課題解決的な学習が展開される際の学習者の学習活動と教員の教授活動を支援するための遠隔教育支援環境を設計して開発することを目的にする. 本論文では,本研究の目的を達成させるために,以下に示す5つの調査・研究・開発の成果がまとめられている. (1) 遠隔教育の支援環境に関する研究動向の調査 (2) 遠隔教育を支援する環境・機能についての整理と必要機能の提案 (3) 「クラス(学級)」と「個」をつなぐ遠隔教育支援環境「つながる授業アプリ」の開発と評価 (4) 「比べる」協働的思考活動支援機能の開発と評価 (5) グループ学習活動・対話状況確認支援機能とグループ活動状況管理機能の開発と評価 (1)では,遠隔教育に関する研究動向を調査した.これらの整理・分類などを踏まえ,遠隔教育における学習環境,学習支援機能,授業支援機能の研究に対する本研究の位置づけを行った. (2)では,遠隔教育をICTで支援する環境について説明した.さらに,2つのつながり(「クラス(学級)」と「個」)を保障する遠隔教育システムと協働学習支援システムに必要な機能を整理した. (3)では,遠隔教育システムと協働学習支援システムの両方の機能を併せ持つ遠隔教育支援環境「つながる授業アプリ」を設計・開発した.さらに,「つながる授業アプリ」のの有用性を評価し,基本機能を完成させた. (4)では,遠隔合同授業における小学生を対象として,より深い学びを実感できることを目的として,グループ活動時の思考に必要なプロセスを整理し,最も基本的な思考活動の1つである「比較思考」を協働的に進めることができる支援を「つながる授業アプリ」の拡張機能として実装した.「比べる」協働的思考活動支援機能は,「比べる」思考手順を1スライドずつ学習者間の協働的な思考手順として提示して,思考活動プロセスをガイドする仕組みである.さらに,開発した支援機能についてその有用性を評価した. (5)では,大学の遠隔教育を対象にして,グループ学習活動における学習者の対話内容の確認や振り返り,教員による見とりを支援する目的として,対話音声データ(バーバル情報)とノート記述データ(ノンバーバル情報)を活用した活動状況・対話状況の可視化機能を「つながる授業アプリ」の拡張機能として実装した.さらに,教員の見とり支援としてグループ活動状況管理機能も拡張機能として実装し,これらの機能の有用性を評価した. 以上により,オンライン授業が展開でき,学習者の個別学習やグループ学習の活動支援や教員の見とり支援が可能な「つながる授業アプリ」の開発・授業実践を通して,遠隔教育において必要な学習環境の要素機能,学習支援・授業支援の機能を確認することができた.
Creators : 横山 誠 Updated At : 2023-06-14 16:40:56
This dissertation focuses on the experiences of a group of Japanese university students who participated in a short-term study abroad program in the Philippines. While the main objective of the four-week sojourn was to improve the participants’ English language skills, I explored the effects of the trip holistically as a qualitative case study to examine the unique learning context of studying English in the Philippines, a relatively new phenomenon that has developed from the turn of the 21st century. The primary form of data I used was interview responses obtained from 14 focal participants among a larger cohort of 103 students who traveled together in the summer of 2018. The target students were mostly low to intermediate level (CEFR A2 to B1) before departure and returned at a marginally higher benchmark (CEFR B1 average) according to standardized testing scores. More importantly, most students did not have extensive international experience prior to the sojourn, and overall they expressed a more open stance to using English for communication after the trip. In this case and context, positive affective development occurred due to intensive one-on-one instruction with Filipino teachers who interacted with the Japanese students in a warm, friendly, and supportive manner. This learning situation is characteristically different from North American and other Western contexts typically associated with English learning, and with its relative ease of access geographically and financially, offers a practical alternative to Japanese students unable to study abroad otherwise. The results of this study indicate how Japanese learners of English adopt subtle changes in outlook through short-term study abroad programs in diversifying contexts. This research contributes significantly to the field of language learning in study abroad by documenting the perspectives of learners from Japan traveling within Asia. Study abroad itself is a relatively new area of inquiry which has focused predominantly on Western learners and contexts. Existing research on Japanese learners tends to concern privileged, advanced-level learners whose experiences may seem removed from the ordinary lives of students attending university in rural areas or those who do not consider themselves academically or socioeconomically exceptional. Furthermore, the amount of existing research on short-term study abroad is severely limited and does not thoroughly account for the experiences of Japanese learners of English in the Philippines, a study abroad destination which has gained substantial popularity but remains underrepresented. Accounting for the social, cultural, and ideological circumstances of learning in a non-native English speaking context in Asia allows for a more nuanced interpretation of how monolingual Japanese speakers first encounter English as an international language. I collected data in multiple forms to document the complexity of the case. As the participants’ English teacher and chaperone to the Philippines, I was immersed in the learning contexts in the students’ home country as well as abroad. Semi-structured interviews before and after the study abroad experience were conducted in the informants’ native language. Written questionnaires were administered to the larger cohort of students who traveled together to obtain a more general assessment of students’ impressions regarding the study abroad experience. Standardized test scores were accessed for reference. These multiple data sources were drawn on to illustrate the changes observed in the perspectives of the focal informants. While the learning experiences of each informant were unique, I identified common themes among the ways students collectively changed their attitudes and beliefs toward English and language learning through their participation in the short-term study abroad program. First, the learners in this study increased their self-confidence and motivation to learn English and overcame their fear, anxiety, and inhibition toward using English to varying degrees. Second, they expanded their interests in learning about other languages and cultures while becoming more aware of the boundaries of their own culture. Third, their perceived communicative ability in English improved, which they found was not the same as having to perform well on standardized English tests. Fourth, participants’ sense of success in improving their English language proficiency was less certain, reflecting their divergent test score gains on standardized exams. These reported changes in perspective were not lifechanging transformations of learners’ social identities, but their previously constructed views of language, culture, communication, and learning were evidently affected. The qualitative effects of study abroad experienced by the informants of this study cannot be assessed adequately with the language proficiency tests highly regarded in mainstream Japanese society. Language ideologies prevalent in the participants’ home and host contexts for learning need to be considered in order to explain why the changes occurred. The learners in this study initially had an additional affective barrier toward communication in intercultural contexts because they could not take advantage of the widespread use of English as a lingua franca without first making efforts to use English itself. Since they were used to monolingual discourses in Japan, the idea of using English as a lingua franca, not only as a “perfect” native language, had to be presented to them in a reallife situation. The study abroad experience nudged learners toward using English in ways that reflect the Global Englishes paradigm. These slight shifts in mindset are indicative of attitudinal changes gradually taking place within Japan and are not restricted to individuals who identify with international communities.
Creators : 池田 理紗 Updated At : 2023-06-13 16:47:24
Not only taste but also flavor has a significant impact on the "deliciousness" of food as perceived by people. Flavor characteristics of food have a significant impact on its palatability and influence the qualitative value of the food itself. In this study, the molecular mechanisms of biosynthesis of flavor compounds derived from amino acids in soybean (Glycine max) and fatty acids in mushrooms were elucidated. In Chapter 1, I identified the characteristic aromatic properties of soybean due to sulfur-containing amino acids. Several soybean germplasms, such as Nishiyamahitashi 98-5 (NH) among local varieties in Nagano Prefecture, have an intense seaweed-like flavor after cooking because of their high seed S-methylmethionine (SMM) content. In this study, I compared the amounts of amino acids in the phloem sap, leaves, pods, and seeds between NH and the common soybean cultivar Fukuyutaka. This revealed a comparably higher SMM content alongside a higher free L-methionine (L-Met) content in NH seeds, suggesting that the SMM-hyperaccumulation phenotype of NH soybean was related to L-Met metabolism in seeds. To investigate the molecular mechanism behind SMM hyperaccumulation, I examined the phenotype-associated gene locus in NH plants. Analyses of the quantitative trait loci in segregated offspring of the cross between NH and the common soybean cultivar Williams 82 indicated that one locus on chromosome 10 explains 71.4% of SMM hyperaccumulation. Subsequent fine-mapping revealed that a transposon of about 6 kbp insertion into the intron of a gene, Glyma.10g172700, is associated with the SMM-hyperaccumulation phenotype. The Glyma.10g172700-encoded recombinant protein showed Met-γ-lyase (MGL) activity in vitro, and the transposon-insertion mutation in NH efficiently suppressed Glyma.10g172700 expression in developing seeds. Exogenous administration of L-Met to sections of developing soybean seeds resulted in transient increases in L-Met levels, followed by continuous increases in SMM concentrations, which was likely caused by L-Met methyltransferase activity in the seeds. Accordingly, I propose that the SMM-hyperaccumulation phenotype is caused by suppressed MGL expression in developing soybean seeds, resulting in transient accumulation of L-Met, which is converted into SMM to avoid the harmful effects caused by excess free L-Met. In Chapter 2, I studied the biosynthesis mechanism of 1-octen-3-ol, the main volatile component of mushrooms. 1-Octen-3-ol is a volatile oxylipin found ubiquitously in Basidiomycota and Ascomycota. As 1-octen-3-ol attracts mosquitoes and flies, its involvement in emitter–receiver ecological communication has been proposed. Although the biosynthetic pathway to form 1-octen-3-ol from linoleic acid through linoleic acid 10(S)-hydroperoxide has been proposed in mushrooms, the enzymes involved in this pathway have not been identified. I determined that the Coprinopsis cinerea dioxygenase 1 and 2 (CcDOX1 and CcDOX2) genes in the mushroom C. cinerea contains an N-terminal cyclooxygenase-like heme peroxidase domain and a C-terminal cytochrome P450-related domain. Through analysis of products formed from linoleic acid by the recombinant CcDOX1 and CcDOX2 proteins, I found that CcDOX1 preferentially catalyzes to form the 10(S)-hydroperoxide of linoleic acid (10S-HPODE), meanwhile CcDOX2 form the 8-hydroperoxide of linoleic acid. Moreover, disruption of Ccdox1 in C. cinerea (ΔCcdox1) mycelia suppressed 1-octen-3-ol synthesis. Administration of the 10S-HPODE to the microsome fraction prepared from mycelia resulted in the efficient production of 1-octen-3-ol. Together, these results indicate that CcDOX1 is essential for the biosynthesis of 1-octen-3-ol as the oxygenase that forms 10S-HPODE, followed by the cleavage enzyme. I studied physiological and ecological significance of 1-octen-3-ol of mushroom. ΔCcdox1 was less attractive to fruit fly larvae, while the feeding behavior of fungus gnats on ΔCcdox1 mycelia showed little difference from that on the mycelia of the wild-type strain. The proliferation of fungivorous nematodes on ΔCcdox1 mycelia was similar to or slightly worse than that on wild-type mycelia. Thus, 1-octen-3-ol seems to be an attractive compound for some animals that interact with mushrooms.
Creators : 手嶋 琢 Updated At : 2023-06-12 13:17:44
In recent years, many reports have been made of damage to reservoir embankments due to frequent heavy rains and earthquakes. “Internal erosion” is the phenomenon in which soil particles move through the pore spaces of embankments and flow out of them because of long-term seepage in the soil structures of reservoirs and river embankments. Internal erosion is classified according to the scale and form of the erosion. “Suffusion” is the phenomenon in which only the fine-grained soil particles move through the pore spaces formed by the coarse-grained soil particles. Suffusion is known to cause an increase in hydraulic conductivity and a decrease in soil bearing capacity. However, the mechanisms and causes of the occurrence and progression of this phenomenon, as well as its effect on soil structures, have not been fully elucidated. Therefore, the purpose of this study was to clarify the effect of suffusion on the strength properties of reservoir embankments as well as the mechanism of the progression of suffusion, focusing on the particle size of the eroded soil particles. In Chapter 1, the background of the study and the classification of internal erosion were provided. In Chapter 2, the mechanism of suffusion and its effect on geomaterials, which have been clarified in previous studies, were described. In Chapter 3, the effect of suffusion on the strength properties was firstly investigated by means of soil samples used for the reservoir embankments which were determined to be at risk of suffusion based on an internal stability evaluation. A triaxial compression testing system was established to simulate the suffusion inside each specimen. In the testing system’s apparatus, only the fine particles were able to be discharged from the specimen through a sieve by supplying water. The results showed that changes in the peak and residual strength occurred independent of changes in the void ratio due to suffusion, and that the strength properties differed depending on the presence or absence of suffusion, even when the void ratio was the same as that before shearing. However, since the amount of erosion was small (less than 0.7% of the total), it is considered that the change in strength was influenced by the fine soil particles that moved through the specimen but remained in the specimen without finally flowing out of it. In Chapter 4, in order to define the mechanism of small-scale internal erosion, a method was devised to examine the temporal changes in the size of the discharged soil particles, focusing on the relationship between the concentration and the turbidity of the drainage. The above method was also applied to the drainage obtained by seepage with suffusion in Chapter 3. As a result, the erosion rates were found to correlate with the particle size of the discharged particles. In Chapter 5, a one-dimensional water-passing experiment with suffusion was conducted to investigate in detail the relationship among the flow rate, soil particle discharge, and turbidity of the drainage. The particle size composition of the discharged soil, which varied with the progress of suffusion, was examined using the method described in Chapter 4. The results showed that, under all conditions, the soil particles with smaller diameters were selected from among those that were able to pass through the wire mesh at the outlet boundary and then discharged. It was also found that the particle size composition of the discharged soil changed with time as the suffusion progressed, and that this trend varied greatly depending on the saturation degree of each specimen before the start of permeation. After the completion of the experiment, the particle size composition of the soil samples showed that not only the distribution of the erodible component in the height direction, but also the particle size composition of the erodible component itself became heterogeneous, suggesting that soil particles with smaller particle sizes moved longer distances through the pores. Furthermore, the effect of overburden pressure on the behavior of suffusion under constant hydraulic gradient conditions was explored, and it was revealed that higher overburden pressure resulted in less frequent suffusion when the hydraulic gradient was large. The particle size composition of the discharged soil was examined, and no difference was found among the various levels of overburden pressure. In addition, the progression of suffusion was investigated under a fluctuating hydraulic gradient. The suffusion continued even after 30 cycles of hydraulic gradient variation. The particle size composition of the discharged soil particles showed that the small soil particles, that flow easily, had already been discharged when the specimen was first subjected to permeation force, and that the soil particles discharged by the change in hydraulic gradient were relatively large in diameter. The particle size of the soil particles discharged by suffusion were seen to depend on the conditions surrounding the occurrence of suffusion and the time of the progression. In studies on suffusion, the particle size composition of the soil discharged by suffusion is a significant factor that changes over time and can be used to evaluate the degree of the progression of suffusion.
Creators : 石丸 太一 Updated At : 2023-06-08 13:37:09
Access to clean water has been crucial global problem, especially with climate change, increasing population, and industrial activities. As one of Malaysia’s leading economic activities, the Oil and Gas Industry generates a massive amount of wastewater called Produced Water (PW). Dissolved organics in produced water, such as organic acids and phenolic compounds, are concerning due to the possibility that they can be toxic, non-biodegradable, and have bioaccumulation properties. Conventional treatments such as adsorption, incineration, and biological treatment seem to have difficulties treating these dilute but toxic components in an economical and environmentally friendly manner. Regulations on wastewater management has also been stricter around the globe. Therefore, there is a need on a new water treatment method to treat the diluted organics in a large volume of wastewater. Membrane technology has been of interest in the water treatment technologies’ industrial and research scenes. It offers simpler configuration and maintenance. However, the application is limited by the reduction of performance over time due to fouling phenomena. Photocatalyst offer an effective method to decompose organics in an environmentally friendly manner. This study researched on photocatalytic removal of diluted organic in water and potential of biofouling reduction by deposition of AgTiO2 coating on membrane surface. In Chapter 1: Introduction, the research background and purpose of this research were discussed. At the end of this chapter, the thesis framework was shown. In Chapter 2: Preparation and characterization of TiO2 and AgTiO2 coatings; the method to prepare AgTiO2 coatings on membrane support were explained. The prepared membranes were characterized with XPS, SEM, TEM, and ICP analysis to understand the prepared coatings. Results shows that the concentration of silver deposited on the membrane can be control by the concentration of silver in the precursor (silver acetate solution) used during the photochemical deposition step. Via XPS, it was found that the state of silver prepared through this method is oxide state. In Chapter 3: Removal of dissolved organic pollutants in water by photooxidation, the photocatalytic performance of prepared membranes was studied. Decomposition of diluted formic acid was performed under UV-light, and the concentration was evaluated using UVspectrophotometer. AgTiO2 membranes show better photocatalytic activity then TiO2 membrane. The concentration of silver on the membrane was found to influence its photocatalytic performance. In relation to PW application which commonly contain high salts, influence of salt types; NaCl, MgSO4, MgCl2 and K2SO4 and concentration were studied. All salts were found to inhibit the membranes’ photocatalytic performance. In Chapter 4: Antibacterial activity of AgTiO2 membranes, the antibacterial activity towards E. coli by prepared AgTiO2 membranes were investigated. Silver dissolution from membrane was found to be significantly increased in the presence of NaCl as compared to only water. Comparing membrane with lower Ag deposition, and around 20 times higher deposition, the silver dissolution from these membranes reached almost the same value after some time. However, as the amount of silver deposited on the membrane was higher, the antibacterial performance show around four times higher than the lower silver membrane. Based on other tests performed, it was concluded that there are potential of contribution from the silver oxide deposited on the membrane surface on the antibacterial activity of the AgTiO2 membranes In Chapter 5: Antibacterial activity in filtration system, prepared AgTiO2 membrane was used to filter E. coli suspension in water. E. coli growth was found to be inhibited by short contact with silver on the coated membrane. Finally, Chapter 6: Conclusion, the thesis was summarized, and future works were proposed.
Creators : Azzah Nazihah binti che abdul rahim Updated At : 2023-06-08 14:09:52
Population growth drives the demand for energy, which is the most pressing human need today. It puts pressure on other related sectors and increases wastewater production, which is a big problem in some countries that is inaccessible to available wastewater treatment facilities. Concerning the SDGs 2030 target, which mentions integrated sectors to deal with environmental issues, energy and water as a part of the water-energy-food nexus have a high linkage to build substantial economic and ecological benefits. Therefore, they have become the core attention of the world at this moment. To deal with the problem solving mentioned above, nowadays, an alternative energy converter integrated wastewater treatment has been massively developed to achieve green label production of products. Many countries, favoured by their scientists and practitioners, compete to find technology that is a user-friendly, eco-friendly, back-to-nature concept, inexpensive and can be accepted in any society stratifications. However, there is an available standalone converter technology known as conventional technology, which is a disintegrated system with no added value. This challenge opens an opportunity to develop a fully integrated system with any advantages. One of the promising technologies needed for solving the environmental problem and simultaneously producing other benefits for human living is a part of the bioelectrochemistry system (BES), which is microbial fuel cell (MFC). It could be easily assisted with the available conventional wastewater treatment, and it gives more benefits not only in energy production but also for remediating the environment through the superior biocatalyst, named electroactive bacteria (EAB), which has the availability to reduce organic and inorganic matter and generating electricity. However, factors affecting MFC have been a drawback in their field application that must be concerned extensively. Therefore, this study accommodates to investigation more in order to get an optimum condition in operation so that the technology could be widely used properly on the full scale. The disadvantages of the air–cathode single-chamber microbial fuel cell (AC-SCMFC) performance can be caused by numerous factors, and retention time (RT) is one such factor. It is difficult to conclude the ideal RT run for the specific tests under the same conditions. To determine the optimum RT for various types of microbial fuel cell (MFC), an AC-SCMFC batch-mode reactor was carried out by comparing different types and concentrations of substrates based on the main parameters of organic removal and power generation. The AC-SCMFC reactor was designed for the effective working volume of 500 mL and operated for 52 d in batch mode with factors being significantly correlated with the performance of the MFC reactor, which were two different substrates, sucrose and acetate, and three different chemical oxygen demand (COD) levels of 400; 1000, and 2500 mg/L (low, medium, and high, respectively) equipped with two graphene nanoplatelets (GNPs)-based electrodes connected to 100 Ω resistance and plugged onto a ii data logger. The results of this study indicated a significant pattern at the medium level, at which the optimum RT of sucrose was achieved at 24 h and that of acetate at 48 h. In comparison, the performances pattern at low and high levels of both substrates was insignificant to determine the optimum RT. For further application, the recommended RT for both substrates at any concentration is 24 h due to high overall performance, and the optimum RT established in this study could be applied to all types of MFC research, particularly in oxidizable or biodegradable organic ranges, which ensures high performance. One of the important factors in enhancing the performance of microbial fuel cells (MFCs) is reactor design and configuration. Therefore, this study was conducted to evaluate the regressors and their operating parameters affecting the double anode chamber–designed dual-chamber microbial fuel cell (DAC-DCMFC) performance. Its primary design consists of two anode chamber compartments equipped with a separator and cathode chamber. The DAC-DCMFCs were parallelly operated over 8 days (60 days after the acclimation period). They were intermittently pump-fed with the different organic loading rates (OLRs), using chemically enriched sucrose as artificial wastewater. The applied OLRs were adjusted at low, medium, and high ranges from 0.4 kg.m-3.d-1 to 2.5 kg.m-3.d-1. The reactor types were type 1 and type 2 with different cathode materials. The pH, temperature, oxidation-reduction potential (ORP), optical density 600 (OD600), chemical oxygen demand (COD), and total organic carbon (TOC) were measured, using standard analytical instruments. In general, the power production achieved a maximum of 866 ± 44 mW/m2, with a volumetric power density of 5.15 ± 0.26 W/m3 and coulombic efficiency of 84%. Two-stage COD and TOC removal at medium OLR achieved a range of 60–80%. Medium OLR is the recommended level to enhance power production and organic removal in DAC-DCMFC. The separated anode chambers into two parts in a dual anode chamber microbial fuel cell adjusted by various organic loadings expressed a preferable comprehension of the integrated MFCs for wastewater treatment. With respect to both studies, RT influences the design and configuration of MFCs, particularly in this regard, modified anode compartment of DCMFCs adapted to the range of oxidizable or biodegradable organics and reactor components towards control and dependent variables provide the simultaneous performance of DCMFCs in organic removal and power generation. In addition, DAC-DCMFC offers an opportunity to achieve optimal conditions in concurrent MFC-assisted wastewater treatment. Therefore, this study is one step closer to understanding the operating conditions comprehensively, which are the dominant factors affecting performance.
Creators : Ganjar Samudro Updated At : 2023-06-08 15:17:05
Indonesia has extreme risk of natural disasters because of its position at the confluence of four tectonic plates: the Asian Continent, the Australian Continent, the Indian Ocean, and the Pacific Ocean. The volcano eruption is one of the geological disasters that frequently occur in this country. Mount Merapi is Indonesia’s most active volcano and is famous worldwide. The evacuation crisis in 2010, the last major eruption, led to many fatalities for humans and cattle. Nowadays, the local government developed the "sister village" strategy for mitigation. That means cooperation within or between the local community has been constructed to provide shelter, logistics, and other disaster-related services. In this scenario, the meeting area and shelter have been coordinated. However, people's behavior has not been fully considered yet in the vulnerability assessment and government's contingency plan. On the other hand, evacuation issues in a volcanic disaster such as difficulty in expecting evacuation period, aging population, missed communication and risk perception, limited private vehicles in the community, and limited evacuation transport and supporters by the government need to be addressed for better mitigation. This situation led some people to walk to the meeting area, and low walking speeds by vulnerable persons may increase the risk and delay during an emergency. The objective of this study is to find the effectiveness of the evacuation process, especially for the vulnerable community in the Mount Merapi area. Especially, this study purposes to develop a “mutual assistance” model for vulnerable people in the affected regencies with the people’s behavior and vehicle ownership as a viewpoint. The first goal is an assessment of the mutual assistance strategy and social vulnerability index (SoVI) of pedestrian evacuation. I conducted the surveys and then analyzed the data using a multicriteria method to obtain the SoVI values for communities. The second goal is the development of the assembly model to support safer and faster evacuation for vulnerable people. The AnyLogic software was selected for model simulation using input parameters from field surveys. In conducting a survey, I measured the walking speed directly of the evacuation drills in four affected regencies. I also investigated the people’s behavior and eruption characteristics using an interview process with stakeholders and group discussions with local communities. After that, I used the multicriteria method and focused on two factors, social and age structure (young, vulnerable, and mutual assistance between them), and risk perception (work, rain, night, alert, and evacuation map). The index reflects the distribution of actual walking speed, mutual assistance, and the government's plan. The result showed that mutual assistance groups have a higher walking speed than vulnerable people but lower than young people. Mutual assistance coordination is crucial to support the vulnerable in shorter evacuation times. The social and age structure of the social vulnerability index has a stronger risk influence than the perception factor in the evacuation process. The successful evacuation of vulnerable people during emergencies is a significant challenge. In this study, a mutual assistance strategy is proposed to support vulnerable people by evacuating them with young people. This strategy was simulated using AnyLogic software with the agent-based model concept. Pedestrians and vehicles played the roles of significant agents in this experiment. Evacuation departure rate, actual walking speed, group size, route, and coordination were crucial agent parameters. Residents’ attitudes, distribution of each agent, and actual walking speed were obtained from surveys. Then, I developed three scenarios and three models for the evacuation process. Scenarios considered traffic conditions of evacuation routes and models represented behavior approach. The results revealed that this mutual assistance model is effective for the rapid evacuation and risk reduction of vulnerable communities where successful evacuation rates have improved. As for mutual assistance behavior, Model 3, where young people are matched with vulnerable people in advance, has shown better results than Model 2. Additionally, Scenario C, where pedestrians have separate lanes from vehicles during the evacuation process, has resulted in more number of vulnerable people reaching the shelter than Scenario B in Model 3. The highest arrival rate was obtained by the combination of scenario C and Model 3. These findings are a novelty in the volcano context and reflect all categories of vulnerable behavior involving the elderly, disabled, children, and pregnant mothers. The model will benefit disaster management studies and authorities’ policies for sustainable evacuation planning and aging population mitigation.
Creators : Faizul Chasanah Updated At : 2023-06-08 15:38:11
Innovation is the practical implementation of ideas that result in the introduction of new goods or services or the improvement in them (Schumpter, 1983). Innovation is closely related to invention as innovation is more on involving the practical implementation of a new or improved invention to make a meaningful impact in a market or society (Schumpter, 1939). On the other hand, innovative design is a process of identifying, pinpointing, and understanding the needs of the user or audience (Shaulis, 2021). Previously, Dixon (1966) defined innovative design as any design that is: new or different, or elegant or uses new ideas, or is an improvement over its peers. Once the market need has been identified, a solution can then be designed. In our proposed innovative design method, we introduced and investigated a method that is able to be applied in designing an intergrated system that could be a valuable solution to the society. This method starts with directly observe activities of things and real people in real trouble in the real field. Then, we think about the value of "I wish there were such things as…", visualize the story, draw a clear sketch to accomplish the story concretely. Next, we solidify the functions and specifications while investigating needs and competition. Then, we create a prototype that able to show and test your ideas, demonstrate to the people who need it, let them experience it, and gain feedback. Lastly, we evaluate the value of product design and development and plan methods for implementing it as an organization, and plan ways to improve and expand globally. All of the steps in this method are important for innovative design, however, in this research this time we focused on co-designing value, big idea, and considering as integrated steps for identifying latent needs of the consumers. It is because identifying needs is an important part in the product development process. Latent needs are those that many consumers recognize as important in a final product but unable to articulate in advance (Ulrich, 2015). The latent needs addressed in this study was focusing on identifying consumer requirements in product development in the innovative design method. The challenge in identifying latent needs is finding the method to elicit from consumers the needs which are not addressed by any inventors yet in the present market but would delight the consumers if delivered tomorrow. The purpose of this study is to propose and verify the method in the elicitation of latent needs from consumer needs by introducing a working prototype to the consumers, interviewing, and analyzing responses from the consumers. This research was conducted during the year the start of the COVID-19 pandemic. As the pandemic spread, most countries were forced to go into lockdown or declare an emergency state. The school was closed and business organizations needed to switch to working from home to prevent the spread. The parents were unable to work from home efficiently as they were worried their children will involve in dangerous incidents if the children were left by themselves. Based on this situation, this study was conducted in finding the latent needs of the parents, childcare workers, and children in order to assist them in going through their problems during this COVID-19 pandemic. The working prototype was used as material to prepare presentation slides for the consumers' interviews. The first presentation slides were focused on the background problems and ideas for the solutions while the second presentation slides provided consumers with a prototype and story of the product that was believed would be one of the solutions to the problems. Interviews were conducted after both slide presentations. Consumers' responses were obtained and interpreted into consumers' needs in terms of product functions. In the first study, consumers' interpreted needs from Problem-based interviews and Prototype and Story-based interviews were compared. Based on the results, latent needs interpreted from interviewees' responses and the categories of the needs obtained from the Prototype-based interviews are more than from the Problem-based interview. The latent needs that we were able to obtain from this research were for example, “The device is able to detect small changes in a child while watching he/she sleeping” which could lead into the prevention of unwanted incident such as sudden infant death syndrome (SIDS). This supports our assumption that showing working prototype-based materials with story descriptions can be effective in uncovering potential latent needs. In the second study, it is assumed that experience, empathy, and knowledge of working prototype is essential elements in product development, therefore, new additional guidelines which are “to write a statement with empathy”, “to write a statement as a designer”, and “to write a statement as someone with experience” were proposed during consumers' needs interpretation to see whether these new guidelines will influence the process of identifying latent needs of consumers. From the result, it is concluded that the number of interpreted needs increased when we applied the new proposed guideline. Although the number is small, the needs might not be interpreted if the new guidelines were not considered. We were also able to obtain a few important latent needs when we applied these new guidelines. A latent need collected from applying the guideline "to write a statement as someone with experience" is “The device is not for teaching love and humanity but for monitoring by watching facial expression, posture, and vital signals such as temperature and heart rate”. We could conclude that including these guidelines upon interpreting raw data from the consumers’ interviews might lead into discovering important and critical latent needs of the consumers. In the third study, a quantitative evaluation method for identifying latent needs was introduced. The consumers' interpreted needs were rated according to a basis of rating from the three perspectives of importance, latent-ness, and technological feasibility. The Degree of Latent Needs (DLN) was calculated by multiplying these three metrics. Based on the result for the average and variance of DLN mean value for each evaluator which is sufficiently small, it indicates that the basis of rating for three metrics of the DLN is effective. The results also indicate that the 20 highest DLN points of the interpreted needs contain attractive features in terms of design. However, we had gotten some pushback on the average of each interpreted need and its variance which indicates opposing opinions among evaluators. As it is possible that attractive needs are hidden and may lead to the discovery of latent needs through individual pinpoint interviews, the interviews with the minority evaluators were conducted. The interview results indicate that the latent needs with low DLN rates but valuable might be able to be discovered by conducting follow-up interviews such as “The device is able to recognize items (food or not) that a child wants to put in the mouth”. From the results in all three studies, we could conclude that a number of important latent needs are able to be elicited from consumers’ needs by applying the proposed method. In our fourth study, a decision-making method based on the patent analysis between the conceptual design stage and the prototyping stage in the innovative design method was introduced. Conducting a patent strategy was assumed to support how to select the right concept precisely. In this study, by conducting a patent search in this stage by the designer who understood best the product functions and working principles, a supporting method was introduced to assist the designer in their decision-making process. Based on the result, the method was able to observe whether there are dominating companies or not for our concept design. If there is a dominating company, the possibility of not being able to produce our concept becomes bigger. This method may be applied as an indicator to support decisionmaking in the concept design stage in the innovative design method, whether to proceed with the concept design or not and to reduce the possibility of product failure in the future. From the results of all the studies, we could conclude that these above methods may be applied as assistive tools to support designers’ understanding of consumers’ requirements and selecting the right concept design.
Creators : Nurhayati Binti Md Issa Updated At : 2023-06-07 14:05:05
Pandemic influenza virus A(H1N1)pdm09 infection occurred in healthy children and young adults, but asthmatic patients presented more rapid progression of respiratory distress and plastic bronchitis. To investigate the pathogenesis of worsening respiratory symptoms after A(H1N1)pdm09 infection, we focused on matrix metalloproteinase‐9 (MMP‐9) and tissue inhibitor of metalloproteinases‐1 (TIMP‐1). MMP‐9 and TIMP‐1 levels in bronchoalveolar lavage fluid and serum from mice with and without asthma were evaluated after A(H1N1)pdm09 or seasonal A(H1N1) infection. MMP‐9 levels were more elevated in Asthma/A(H1N1)pdm09‐infected mice than in non‐Asthma/A(H1N1)pdm09‐infected mice on both 3 and 7 days post‐infection. Immunohistochemical findings in this pneumonia model showed that MMP‐9 and TIMP‐1 positive cells were observed in blood vessels and bronchus of lung tissue in severe pathological findings of pneumonia with asthma. Microscopically, shedding cells and secretions were conspicuous in the trachea on days 3 and 7 postinfection, in the A(H1N1)pdm09‐infected mice with asthma. Our results suggest that MMP‐9 and TIMP‐1 expressions are related to severe pneumonia in the A(H1N1)pdm09 infection with asthma, leading to cause epithelial cell shedding.
Creators : 木村 献 Updated At : 2023-05-24 13:39:59
小胞体ストレスの増加は、動脈硬化において血管平滑筋培養細胞(VSMCs)の形質転換(分化→脱分化)と強く関連している。小胞体のCa2+貯蔵量減少は、VSMCs における小胞体ストレスの増加の主要な原因の一つである。リアノジン受容体(RyR)は筋小胞体膜上に存在する主要なCa2+放出チャネルである。正常細胞の安静状態ではカルモジュリン(CaM)はRyR と結合し、RyR を閉鎖した状態で安定化させている。CaM とRyR の結合が減弱すると、RyR から異常なCa2+漏出が起こり、Ca2+貯蔵量が減少し、小胞体ストレスが増加する原因となり得る。そこで我々は、マウスのVSMCs を用いてRyR に結合しているCa(CaM-RyR)が小胞体ストレスにより引き起こされるVSMCs の形質転換に重要な役割を果たしているか否か、また、CaM-RyR の結合親和性を高める作用を有するダントロレン(DAN)がVSMCs の形質転換に影響を与えるか否かを評価した。 小胞体ストレスによりCaM がRyR から解離し、核内へ移行することにより、MEF2 とKLF5 の核内での発現量が増加し、このMEF2-KLF5 のシグナル伝達経路が活性化することでVSMCs が形質転換(分化→脱分化)し、増殖能や遊走能を有するようになり動脈硬化巣の形成や不安定化につながるという新たな知見を得ることができた。さらにCaM-RyR の結合親和性を高めるDAN は、RyR チャネルを安定化させ、異常なCa2+漏出を抑制し、小胞体内のCa2+貯蔵量を保持することで小胞体ストレスの増加を抑制し、さらにCaM の核内への移行を制御することで、MEF2-KLF5 経路の活性化を抑制し、その結果としてVSMCs の形質転換を抑制することが示され、動脈硬化巣の進展化、不安定化に対する全く新しい治療戦略となり得る可能性があることが示唆された。
Creators : 内田 智之 Updated At : 2023-05-24 14:03:54
ミエリン関連糖蛋白 (myelin-associated glycoprotein: MAG) は,神経組織の髄鞘に局在する膜貫通糖蛋白であり,MAGに対するIgM型自己抗体 (MAG抗体) を有する患者では脱髄性末梢神経障害をきたす.末梢神経には血液神経関門 (blood-nerve barrier: BNB) があるために,通常は免疫グロブリンなどの大きな分子が神経内に侵入することはできない.しかし,MAGニューロパチー患者から採取した腓腹神経内有髄神経線維の髄鞘にはMAG抗体が沈着しており,MAG抗体はBNBを通過していることが想定される.MAG抗体のBNB通過機序を明らかにすることを目的に,MAGニューロパチー患者血清,ヒトBNB構成内皮細胞株と周皮細胞株,MAGニューロパチー患者から採取した腓腹神経検体を用いて解析を行った.MAGニューロパチー患者血清を作用させた内皮細胞に対して,全RNAトランスクリプトーム解析と免疫染色を用いたハイコンテントイメージング解析を行い,NF-κBの活性化とTNF-αの発現増加を確認した.次に内皮細胞と周皮細胞を共培養したBNB in vitroモデルで透過性を解析した. MAGニューロパチー患者血清を作用させた結果,10 kDaデキストランやIgGの透過性を変化させることなく,IgMやMAG抗体の透過性を亢進させ,TNF-αの中和抗体を添加することでIgMやMAG抗体の透過性は抑制された.電子顕微鏡による観察ではMAGニューロパチー患者の腓腹神経内でBNBを構成する微小血管の密着結合は保たれており,内皮細胞内に多数の小胞が確認された.MAGニューロパチー患者では,MAG抗体はBNB構成内皮細胞の自己分泌TNF-αの増加を介して内皮細胞質内をトランスサイトーシスの機序により通過していることが示唆された.TNF-α阻害薬は既存の薬剤であり,本研究結果から,TNF-α阻害薬によるMAGニューロパチー患者への新たな治療戦略が期待される.
Creators : 佐藤 亮太 Updated At : 2023-05-24 14:10:24
本研究の目的は、皮膚潰瘍モデルマウスにおいて、凍結保存した他家線維芽細胞シートの治療効果を検討することである。他家細胞シートの凍結保存が可能であれば、様々な疾患への応用が可能であり、大幅なコストダウンによる再生医療の普及に貢献できると考えられる。本研究では、3Dフリーザーを用いて線維芽細胞シートの凍結を行った。凍結融解した線維芽細胞シートは、非凍結線維芽細胞シートと比較して、細胞生存率は約80であり、vascularendothelial growth factor VEGF )、hepatocyte growth factor HGF)、stromalderived factor 1α SDF1αの培養上清中の濃度が50%以上で、transforminggrowth factor β1 TGFβ1の分泌能は同等であった。皮膚潰瘍モデルマウスにおいて、非凍結線維芽細胞シート群と凍結融解した線維芽細胞シート群の間で、自家細胞、他家細胞のどちらも創傷治癒率に差はなかった。また、血管新生の程度も同等であった。治癒組織におけるCD3陽性細胞数は、自家線維芽細胞シート群と比較して他家線維芽細胞シート群で多く見られた。しかし、病理組織学的には、凍結融解した他家線維芽細胞シート群の線維化、新生血管密度、創傷治癒速度は、非凍結他家線維芽細胞シート群に比べて凍結融解した自家線維芽細胞シート群に類似していた。これらの結果から、凍結融解した他家線維芽細胞シートが難治性皮膚潰瘍に対する有望な治療オプションとなる可能性が示唆された。
Creators : 池 創一 Updated At : 2023-05-24 14:52:02
細胞シート移植治療の普及には利便性の高い細胞シートの保存方法の開発が不可欠である。細胞シートから分泌される成長因子によって創傷治癒は促進されると考えられてきたため、その保存には細胞生存率が重要視されてきた。そのため、積層線維芽細胞シートの乾燥保存に関する検討はこれまでにない。本研究では、乾燥保存した積層線維芽細胞シート(Dryシート)を開発し、糖尿病マウス全層皮膚欠損モデルでの創傷治癒促進効果を検証した。 マウスの尾から単離した線維芽細胞を用いて、積層線維芽細胞シート(Livingシート)を作製した。Livingシートを風乾させ、Dryシートとした。Livingシートに凍結解凍操作を繰り返してFreeze-thaw(FT)シートとした。各シートを培地に浸漬して溶出液とし、各溶出液中の成長因子を測定した。Vascular endothelial growth factor(VEGF)とhepatocyte growth factor(HGF)はDryシートとLivingシートで検出したのに対し、fibroblast growth factor-2(FGF-2)とhigh mobility group box 1(HMGB1)はDryシートのみで検出した。FTシートではこれらの成長因子をほとんど検出しなかった。細胞シートの溶出液を添加して線維芽細胞を培養し、溶出液の生理活性を線維芽細胞増殖試験で検討した。DryシートはLivingシートと比べ、細胞増殖と成長因子産生量を有意に促進し、FGF-2中和抗体で阻害すると、この細胞増殖反応は抑制された。糖尿病マウス全層皮膚欠損モデル(C57BL/6N)において、自家及び他家(C3H/He)の線維芽細胞から作製したDryシート貼付群は無治療群に比べ、創の閉鎖を有意に促進した。Dryシートは常温(23℃)よりも冷蔵(4℃)での保存安定性に優れ、少なくとも4週間の冷蔵保存ではDryシートのFGF-2の減少を認めなかった。 以上から、DryシートはFGF-2の放出という新たな作用機序で創傷治癒を促進することが明らかになった。他家細胞から作製されたDryシートは、創傷治癒を促す再生医療において新たな扱いやすい被覆材であることが示唆された。
Creators : 松野 祐太朗 Updated At : 2023-05-24 16:26:24