— Invited Review — The role of rumen microbiota in enteric methane mitigation for sustainable ruminant production

Shinkai Takumi,Takizawa Shuhei,Fujimori Miho,Mitsumori Makoto 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.2

Ruminal methane production functions as the main sink for metabolic hydrogen generated through rumen fermentation and is recognized as a considerable source of greenhouse gas emissions. Methane production is a complex trait affected by dry matter intake, feed composition, rumen microbiota and their fermentation, lactation stage, host genetics, and environmental factors. Various mitigation approaches have been proposed. Because individual ruminants exhibit different methane conversion efficiencies, the microbial characteristics of low-methane-emitting animals can be essential for successful rumen manipulation and environment-friendly methane mitigation. Several bacterial species, including <i>Sharpea</i>, uncharacterized Succinivibrionaceae, and certain <i>Prevotella</i> phylotypes have been listed as key players in low-methane-emitting sheep and cows. The functional characteristics of the unclassified bacteria remain unclear, as they are yet to be cultured. Here, we review ruminal methane production and mitigation strategies, focusing on rumen fermentation and the functional role of rumen microbiota, and describe the phylogenetic and physiological characteristics of a novel <i>Prevotella</i> species recently isolated from low methane-emitting and high propionate-producing cows. This review may help to provide a better understanding of the ruminal digestion process and rumen function to identify holistic and environmentally friendly methane mitigation approaches for sustainable ruminant production. Ruminal methane production functions as the main sink for metabolic hydrogen generated through rumen fermentation and is recognized as a considerable source of greenhouse gas emissions. Methane production is a complex trait affected by dry matter intake, feed composition, rumen microbiota and their fermentation, lactation stage, host genetics, and environmental factors. Various mitigation approaches have been proposed. Because individual ruminants exhibit different methane conversion efficiencies, the microbial characteristics of low-methane-emitting animals can be essential for successful rumen manipulation and environment-friendly methane mitigation. Several bacterial species, including Sharpea, uncharacterized Succinivibrionaceae, and certain Prevotella phylotypes have been listed as key players in low-methane-emitting sheep and cows. The functional characteristics of the unclassified bacteria remain unclear, as they are yet to be cultured. Here, we review ruminal methane production and mitigation strategies, focusing on rumen fermentation and the functional role of rumen microbiota, and describe the phylogenetic and physiological characteristics of a novel Prevotella species recently isolated from low methane-emitting and high propionate-producing cows. This review may help to provide a better understanding of the ruminal digestion process and rumen function to identify holistic and environmentally friendly methane mitigation approaches for sustainable ruminant production.

Formulations of the Einstein Equations for Numerical Simulations

Hisaaki Shinkai 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.6

We review recent efforts to re-formulate the Einstein equations for fully relativistic numerical simulations. The so-called numerical relativity is a promising research field matching with ongoing gravitational wave observations. In order to complete long-term and accurate simulations of binary compact objects, people seek a robust set of equations against the violation of constraints. Many trials have revealed that mathematically equivalent sets of evolution equations show different numerical stabilities in free evolution schemes. In this article, we overview the efforts of the community, categorizing them into three directions: (1) modifying of the standard Arnowitt-Deser- Misner (ADM) equations initiated by the Kyoto group [the so-called Baumgarte-Shapiro-Shibata- Nakamura (BSSN) equations], (2) rewriting the evolution equations in a hyperbolic form and (3) constructing an \asymptotically constrained" system. We then introduce our series of works that tries to explain these evolution behaviors in a unified way by using an eigenvalue analysis of the constraint-propagation equations. The modifications of (or adjustments to) the evolution equations change the character of constraint propagation and several particular adjustments using constraints are expected to damp the constraint-violating modes. We show several sets of adjusted ADM and BSSN equations, together with their numerical demonstrations. We review recent efforts to re-formulate the Einstein equations for fully relativistic numerical simulations. The so-called numerical relativity is a promising research field matching with ongoing gravitational wave observations. In order to complete long-term and accurate simulations of binary compact objects, people seek a robust set of equations against the violation of constraints. Many trials have revealed that mathematically equivalent sets of evolution equations show different numerical stabilities in free evolution schemes. In this article, we overview the efforts of the community, categorizing them into three directions: (1) modifying of the standard Arnowitt-Deser- Misner (ADM) equations initiated by the Kyoto group [the so-called Baumgarte-Shapiro-Shibata- Nakamura (BSSN) equations], (2) rewriting the evolution equations in a hyperbolic form and (3) constructing an \asymptotically constrained" system. We then introduce our series of works that tries to explain these evolution behaviors in a unified way by using an eigenvalue analysis of the constraint-propagation equations. The modifications of (or adjustments to) the evolution equations change the character of constraint propagation and several particular adjustments using constraints are expected to damp the constraint-violating modes. We show several sets of adjusted ADM and BSSN equations, together with their numerical demonstrations.

The Lempel-Ziv Complexity in Infinite Ergodic Systems

Soya Shinkai,Yoji Aizawa 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.50 No.1I

The L1-function property of the Lempel-Ziv complexity of 2- and 3-symbol sequences is numerically studied in the framework of the in.nite ergodic theory. Our results show that the L1-function property is consistent in the case of plural indierent .xed points with same order singularities near each point.

Effect of Gun Nozzle Geometry, Increase in the Entrance Convergent Section Length and Powder Injection Position on Cold Sprayed Titanium Coatings

Sakaki Kazuhiko,Shinkai Shuhei,Ebara Nobuharu,Shimizu Yasuo 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Nozzle geometry influences gas dynamics making sprayed particle behavior one of the most important parameters in cold spray process. Gas flows at the entrance convergent section of the nozzle takes place at relatively high temperature and are subsonic. Thus, this region is a very suitable environment for heating spray particle. In this study, numerical simulation and experiments were conducted to investigate the effect of nozzle contour, entrance geometry of nozzle and powder injection position at nozzle on the cold spray process. The process changes were observed through numerical simulation studies and the results were used to find a correlation with coating properties.

Novel Silica Nanotubes Using a Library of Carbohydrate Gel Assemblies as Templates for Sol-Gel Transcription in Binary Systems

정종화,이심성,Seiji Shinkai,Rika Iwaura,Toshimi Shimizu* 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.1

한국 노인에서의 한글판 Kaigo-Yobo Checklist의 타당도 및 신뢰도

황환식,윤종률,박병주,최현림,권인순,Shinkai Shoji,Takahashi Ryutaro 대한노인병학회 2012 Annals of geriatric medicine and research Vol.16 No.3

Background: This study was done to evaluate the validity and reliability of the Kaigo-Yobo (K-Y) checklist in the Korean elderly population. Methods: The study population included 283 men and women over 65 years who visited the three community senior’s welfare centers located in Seoul and Gyeonggi province from March 29, 2011 to May 26, 2011. The Korean frailty index (FI), Japanese K-Y checklist, Cardiovascular Health Study frailty index (CHSFI), activities of daily living, and Korean Mini-Mental Status Examination were completed for each participant. Reliability was tested by internal consistency (Cronbach's alpha), as was the test-retest reliability, at a 2-week interval. Validity was tested by the area under the curve (AUC) from the receiver operating characteristics curve as a predictor of frailty according to the CHS criteria and the validity index estimated by the reliability index. Results: The correlation coefficients between Korean FI and K-Y checklist, Korean FI and CHSFI, and K-Y checklist and CHSFI were 0.61, 0.43, and 0.44 respectively. The range of Kappa value for each item on the Korean FI was 0.28 to 0.60and 0.19 to 0.65 for the K-Y checklist. Cronbach's alpha for the Korean FI was 0.58 and 0.64 for the K-Y checklist. The AUC for the Korean FI was 0.79, and 0.64 for the K-Y checklist. The validity index for the items on the Korean FI ranged from 0.28-0.53 to 0.60-0.78 and 0.19-0.44 to 0.65-0.81 for the K-Y checklist. Conclusion: The K-Y checklist is a valid and reliable instrument to measure frailty in the Korean elderly population. Followup studies are needed. 연구배경: 일본에서 개발되어 사용되고 있는 노쇠측정도구인 Kaigo-Yobo checklist를 한국 노인을 대상으로 신뢰도와타당도를 평가하고 한국형 노쇠측정도구와 비교 분석하여한국 노인의 노쇠 측정과 진단에 도움이 되고자 한다. 방법: 수도권 소재 복지관 3곳에 등록된 65세 이상의 한국인283명을 대상으로 2011년 3월부터 5월까지 면접조사 방식으로 한국형 노쇠측정도구, 일본의 Kaigo-Yobo checklist와Cardiovascular Health Study (CHS) 노쇠 지표, 한국형 일상생활 활동 지표(Korean activities of daily living) 등을 측정하였다. 1차 조사 2주 후 한국형 노쇠측정도구와 일본의 Kaigo-Yobo checklist를 재 측정하였다. 결과: 한국형 노쇠측정도구와 Kaigo-Yobo checklist 사이의상관 지수 0.61이었고, CHS 노쇠 지표와의 상관 지수는 0.43이었다. 그리고 CHS 노쇠 지표와 Kaigo-Yobo checklist 사이의상관 지수는 0.44이었다. 검사-재검사법의 문항별 kappa값은 한국형 노쇠측정도구에서는 0.28-0.60이었고 Kaigo-Yobo checklist에서는 0.19-0.65이었다. 그리고 노쇠측정도구의 내적 일치도를 나타내는Cronbach’s alpha값은 한국형에서 0.58이었고, Kaigo-Yobo checklist에서는 0.64이었다. CHS 노쇠 지표에 의한 노쇠 여부를 기준으로 한국형 노쇠측정도구와 Kaigo-Yobo checklist의receiver operating characteristics 곡선 아래 영역의 면적률이한국형 노쇠측정도구는 0.79, Kaigo-Yobo checklist에서는0.78이었다. 검사-재검사에 의해 산출된 신뢰도 계수를 이용한 타당도 계수의 범위는 한국형 노쇠측정도구에서는 각 문항별로 0.28-0.53에서 0.60-0.78까지 나타났으며, Kaigo-Yobo checklist에서는 각 문항별로 0.19-0.44에서 0.65-0.81까지나타났다. 결론: 양국의 노쇠측정도구는 신뢰도와 타당도가 유의하게확인되었다. 양국 노인병학회의 상호 교류와 협력을 통한노쇠측정도구의 후속 연구가 요구된다.

Triangular shaped type-2 fuzzy numbers: Application to type-2 fuzzy differential equations

Norihiro Someyama,Hiroaki Uesu,Kimiaki Shinkai,Shuya Kanagawa 원광대학교 기초자연과학연구소 2022 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.24 No.1

It is generally difficult to compute the level cut sets of type-2 fuzzy sets, so type-2 fuzzy sets that are more naturally represented and whose level cut sets can be computed relatively easily are desired. Then, we introduce a new type-2 fuzzy number called Triangular Shaped Type-2 Fuzzy Number in this paper. Moreover, we study calculus for type-2 fuzzy-number-valued functions and solve the problem of a fuzzy differential equation whose initial value is this type-2 fuzzy number.

Follow-up Study on Electroconvulsive Therapy in Treatment-resistant Depressed Patients after Remission: A Chart Review

Yuki Tokutsu,Wakako Umene-Nakano,Takahiro Shinkai,Reiji Yoshimura,Tatsuya Okamoto,Asuka Katsuki,Hikaru Hori,Atsuko Ikenouchi-Sugita,Kenji Hayashi,Kiyokazu Atake,Jun Nakamura 대한정신약물학회 2013 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.11 No.1

Objective: Electroconvulsive therapy (ECT) has proven to be effective in treatment-resistant depression (TRD). In recent reports,70% to 90% of patients with TRD responded to ECT. However, post-ECT relapse is a significant problem. There are no studies investigating risk factors associated with reintroducing ECT in depressive patients after remission previously achieved with former ECT. The aim of the present study is to examine such risk factors using a sample of TRD patients. Methods: We conducted a chart review to examine patient outcomes and adverse events over short- and long-term periods. Forty-two patients met the criteria for major depressive disorder. Results: The response rate was 85.7% (36/42). There were no significant differences in the baseline characteristics of patients exhibiting remission, response or non-response. The rate of adverse events was 21.4% (9/42). Among 34 patients who were available for follow-up, 18 patients relapsed (relapse rate, 52.9%), and 6 patients were reintroduced to ECT. The patients’ age and age of onset were significantly higher in the re-ECT group than non re-ECT group. Conclusion: Our results suggest that older age and older age of onset might be considered for requirement of re-ECT after remission previously achieved with former ECT.

Fabrication of silica nanotubes by using self-assembled gels and their applications in environmental and biological fields

Jung, Jong Hwa,Park, Minsung,Shinkai, Seiji Royal Society of Chemistry 2010 Chemical Society reviews Vol.39 No.11

<P>This <I>critical review</I> focuses on the preparation methods of a variety of the silica nanotubes by self-assembled organogels and the recent development of silica-based organic–inorganic hybrid nanomaterials for use as chemosensors in environmental studies as well as adsorbents for inorganic guest molecules and in biological applications for delivery of organic guest molecules (127 references).</P> <P>Graphic Abstract</P><P>This critical review focuses on the recent development of silica nanotubes in environmental and biological fields. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c002959a'> </P>

Luminescent Calix[4]arene-Based Metallogel Formed at Different Solvent Composition

Park, Jaehyeon,Lee, Ji Ha,Jaworski, Justyn,Shinkai, Seiji,Jung, Jong Hwa American Chemical Society 2014 Inorganic Chemistry Vol.53 No.14

<P>We have synthesized a calix[4]arene derivative (<B>1</B>) containing terpyridine and showed that gelation occurred in the presence of Pt<SUP>2+</SUP> in DMSO/H<SUB>2</SUB>O of varying compositions. Gelation was presumably mediated by the Pt–Pt and π–π stacking interactions. The scanning electron microscopy image of the xerogel showed a spherical structure with diameter of 1.8–2.1 μm. Interestingly, the metallogel showed strong luminescence enhancement, which was dependent on the DMSO/H<SUB>2</SUB>O ratio of the solvent. We examined the effects of concentration, temperature, and time resolution on the luminescence emission of both the gel <B>1</B>-Pt<SUP>2+</SUP> and the sol <B>1</B>-Pt<SUP>2+</SUP>. The luminescence lifetimes of the metallogel were particularly long, on the order of several microseconds. The luminescence lifetimes were also strongly dependent on the solvent composition. We also determined the thermodynamic parameters for the self-assembly of the gel by the Birks kinetic scheme. Furthermore, the rheological properties of the metallogels in the presence of more than 4.0 equiv of Pt<SUP>2+</SUP> were independent of the concentration of Pt<SUP>2+</SUP> applied.</P><P>A calix[4]arene derivative containing terpyridine was synthesized, and it was shown that gelation occurred in the presence of Pt<SUP>2+</SUP> in solutions of DMSO/H<SUB>2</SUB>O of varying compositions. Interestingly, the metallogel showed strong luminescence enhancement, which depended on the DMSO/H<SUB>2</SUB>O ratio of the solvent.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2014/inocaj.2014.53.issue-14/ic500266f/production/images/medium/ic-2014-00266f_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ic500266f'>ACS Electronic Supporting Info</A></P>