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1. Antibacterial Effects of Disulfiram in Helicobacter pylori

Author

Kobatake T, Ogino K, Sakae H, Gotoh K, Watanabe A, Matsushita O, Okada H, and Yokota K

Subjects
disulfiram, helicobacter pylori, urease, vacuolating toxin, caga, Infectious and parasitic diseases, RC109-216
Abstract

Tomomi Kobatake,1 Keiki Ogino,2 Hiroyuki Sakae,3 Kazuyoshi Gotoh,4 Akari Watanabe,5 Osamu Matsushita,4 Hiroyuki Okada,3 Kenji Yokota1 1Graduate School of Health Science Okayama University, Okayama, 700-8558, Japan; 2Department of Environmental Medicine, Koch Medical School, Nankoku-shi, 783-8505, Japan; 3Department of Gastroenterology and Hepatology, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700-8558, Japan; 4Department of Bacteriology, Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700-8558, Japan; 5Department of Oral Health Care and Rehabilitation, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, 770-8501, JapanCorrespondence: Kenji YokotaGraduate School of Health Science Okayama University, Okayama, 700-8558, JapanTel/Fax +81-86-235-6846Email yokochan@md.okayama-u.ac.jpBackground: Helicobacter pylori infection poses a risk of the occurrence of gastrointestinal diseases, such as gastric cancer. Its incidence rate is significantly reduced by eradication, and thereby, eradication therapy is generally performed. Disulfiram is an oral prescription drug mainly used for the treatment of alcohol dependence. In recent years, reports have been made on its anticancer and antibacterial effects, and thus, it has recently become an interesting subject. This study aimed to examine the antibacterial activity of disulfiram, investigate the presence or absence of its antibacterial activity on H. pylori, and determine whether it could be a new bactericidal drug against drug-resistant H. pylori.Materials and Methods: Drug-sensitive strains of H. pylori and amoxicillin-resistant, clarithromycin-resistant, and metronidazole-resistant strains were used, and a growth inhibition test of H. pylori using disulfiram was performed. Furthermore, the expression of urease, vacuolating cytotoxin A (VacA), and CagA, the virulence proteins of H. pylori, was quantitatively analyzed using the Western blotting method. In addition, for H. pylori used in this study, the 16SrDNA sequence, a ribosomal gene involved in protein production, was analyzed to examine the presence or absence of gene mutation.Results: Disulfiram suppressed the growth of 7 out of 12 H. pylori strains at 1 μg/mL, and no correlation was observed between their susceptibility/resistance to current eradication antimicrobial drugs and disulfiram resistance. Disulfiram reduced the expression levels of urease, VacA, and CagA proteins. H. pylori, which showed resistance to disulfiram, tended to have fewer gene deletions/insertions in the 16S rDNA sequence; however, no specific mutation was detected.Conclusion: Disulfiram has a bactericidal effect on H. pylori at low concentrations, suggesting that it can be used as a supplement for current H. pylori eradication drugs.Keywords: disulfiram, Helicobacter pylori, urease, vacuolating toxin, CagA

Published
2021

2. Prediction Model of Deep Learning for Ambulance Transports in Kesennuma City by Meteorological Data

Author

Watanabe O, Narita N, Katsuki M, Ishida N, Cai S, Otomo H, and Yokota K

Subjects
ambulance transport, cardiopulmonary arrest, deep learning, meteorological factors, trauma, Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9
Abstract

Ohmi Watanabe,1 Norio Narita,2 Masahito Katsuki,2 Naoya Ishida,1 Siqi Cai,1 Hiroshi Otomo,3 Kenichi Yokota3 1Kesennuma City Hospital, Kesennuma, Miyagi 988-0181, Japan; 2Department of Neurosurgery, Kesennuma City Hospital, Kesennuma, Miyagi 988-0181, Japan; 3Department of Surgery, Kesennuma City Hospital, Kesennuma, Miyagi 988-0181, JapanCorrespondence: Norio NaritaDepartment of Neurosurgery, Kesennuma City Hospital, 8-2, Akaiwa-Suginosawa, Kesennuma, Miyagi, Japan, 988-0181 Tel/ Fax +81-226-22-7100Email nnarita@mbr.nifty.comPurpose: With the aging population in Japan, the prediction of ambulance transports is needed to save the limited medical resources. Some meteorological factors were risks of ambulance transports, but it is difficult to predict in a classically statistical way because Japan has 4 seasons. We tried to make prediction models for ambulance transports using the deep learning (DL) framework, Prediction One (Sony Network Communications Inc., Tokyo, Japan), with the meteorological and calendarial variables.Materials and Methods: We retrospectively investigated the daily ambulance transports and meteorological data between 2017 and 2019. First, to confirm their association, we performed classically statistical analysis. Second, to test the DL framework’s utility for ambulance transports prediction, we made 3 prediction models for daily ambulance transports (total daily ambulance transports more than 5 or not, cardiopulmonary arrest (CPA), and trauma) using meteorological and calendarial factors and evaluated their accuracies by internal cross-validation.Results: During the 1095 days of 3 years, the total ambulance transports were 5948, including 240 CPAs and 337 traumas. Cardiogenic CPA accounted for 72.3%, according to the Utstein classification. The relation between ambulance transports and meteorological parameters by polynomial curves were statistically obtained, but their r2s were small. On the other hand, all DL-based prediction models obtained satisfactory accuracies in the internal cross-validation. The areas under the curves obtained from each model were all over 0.947.Conclusion: We could statistically make polynomial curves between the meteorological variables and the number of ambulance transport. We also preliminarily made DL-based prediction models. The DL-based prediction for daily ambulance transports would be used in the future, leading to solving the lack of medical resources in Japan.Keywords: ambulance transport, cardiopulmonary arrest, deep learning, meteorological factors, trauma

Published
2021

3. Increase in antibiotic resistant Helicobacter pylori in a University Hospital in Japan

Author

Kageyama C, Sato M, Sakae H, Obayashi Y, Kawahara Y, Mima T, Matsushita O, Yokota K, Mizuno M, and Okada H

Subjects
Helicobacter pylori, resistance, clarithromycin, amoxicillin, University hospital, genotype, Infectious and parasitic diseases, RC109-216
Abstract

Chihiro Kageyama,1 Mayu Sato,1 Hiroyuki Sakae,2 Yuka Obayashi,2 Yoshiro Kawahara,2 Takehiko Mima,3 Osamu Matsushita,3 Kenji Yokota,1 Motowo Mizuno,4 Hiroyuki Okada2 1Graduate School of Health Science, Medical Technology, Okayama University, Okayama 700-8558, Japan; 2Gastroenterology and Hepatology, Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan; 3Bacteriology, Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan; 4Department of Gastroenterology and Hepatology, Kurashiki Central Hospital, 710-8602, Japan Background: Eradication effectively prevents Helicobacter pylori-associated diseases; however, H. pylori antibiotic resistance has increased throughout Japan and worldwide. This study aimed to assess rates of resistance to antibiotics; amoxicillin, clarithromycin and metronidazole in a University Hospital in Japan. Materials and methods: H. pylori (208 strains) were isolated from patients at the Okayama University Hospital in Japan. The minimum inhibitory concentrations (MIC) were determined using the mean values of the E-test to determine the antimicrobial susceptibilities of the strains. Sequencing and gene analysis were performed to analyze resistance genes to clarithromycin and amoxicillin. Results: Rates of amoxicillin, clarithromycin, and metronidazole resistance were 13%, 48%, and 49%, respectively. Genetic analysis indicated that the A2143G point mutation in 23S rDNA is closely associated with the MIC of clarithromycin. The MIC in amoxicillin-resistant strains increased with an increase in the number of PBP1A amino acids mutations. Conclusion: Genetic analysis for resistant strains is not clinically effective in cases of amoxicillin resistance. Numerous bacteria with already high antibiotic resistance rates have been isolated in large hospitals such as a University Hospital. For effective eradication therapy, MIC measurement should be considered via several methods. Keywords: Helicobacter pylori, resistance, clarithromycin, amoxicillin, University Hospital, genotype

Published
2019

4. Strategies to encourage physical activity in patients with hemophilia to improve quality of life

Author

Goto M, Takedani H, Yokota K, and Haga N

Subjects
Hemophilia, Physical Activity, Exercise Adherence, Behavior Change, Risk management, Diseases of the blood and blood-forming organs, RC633-647.5
Abstract

Miwa Goto,1 Hideyuki Takedani,2 Kazuhiko Yokota,1 Nobuhiko Haga3 1Rehabilitation Center, The University of Tokyo Hospital, 2Department of Joint Surgery, Research Hospital of the Institute of Medical Science, The University of Tokyo, 3Department of Rehabilitation Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan Abstract: Hemophilia is a bleeding disorder caused by a congenital abnormality of blood coagulation. Until the mid-1970s, patients with hemophilia (PWH) were advised to refrain from physical activity (PA) because of a perceived increased risk of bleeding. Since then, PA, which is recognized as being essential for health maintenance, is now recommended by the World Federation of Hemophilia. Moreover, a number of studies reported that PA can improve treatment efficacy and prevent bleeding in PWH. Physical assessment and intervention in PA are currently used in clinical practice. However, the necessity of PA is not emphasized, and many PWH generally have low- to- no PA. Therefore, a behavior change approach to encourage patient motivation is becoming ever more important. In this article, we review articles addressing PA in PWH and discuss strategies to encourage PA through a behavior change approach by focusing on factors relevant to hemophilia, such as benefits and bleeding risk of PA, risk management of bleeding, PA characteristics, and difficulty with exercise adherence. The trust relationship between clinicians and patients, a transtheoretical model of behavior change, and motivation theory as approaches to promote PA are introduced. Finally, we review a case report of the clinical success of a behavior change approach to promote PA. Many PWH find it difficult to continue PA because of aging, fear of bleeding, insufficient recognition of PA benefits, and psychological problems. Therefore, it is essential and important to perform prophylaxis with PWH and to heighten their understanding of the benefits and risks of PA, before initiating the exercise regimen. For those patients who find it difficult to participate in PA, it is necessary to plan individual-based behavior change approach and encourage self-efficacy. Keywords: hemophilia, physical activity, exercise adherence, behavior change, risk management

Published
2016

5. Spectroscopy of $A=9$ hyperlithium by the $(e,e^{\prime}K^{+})$ reaction

Author

Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Meekins, D., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.

Subjects
Nuclear Experiment
Abstract

Missing mass spectroscopy with the $(e,e^{\prime}K^{+})$ reaction was performed at Jefferson Laboratory's Hall C for the neutron rich $\Lambda$ hypernucleus $^{9}_{\Lambda}{\rm Li}$. The ground state energy was obtained to be $B_{\Lambda}^{\rm g.s.}=8.84\pm0.17^{\rm stat.}\pm0.15^{\rm sys.}~{\rm MeV}$ by using shell model calculations of a cross section ratio and an energy separation of the spin doublet states ($3/2^{+}_1$ and $5/2^{+}_1$). In addition, peaks that are considered to be states of [$^{8}{\rm Li}(3^{+})\otimes s_{\Lambda}=3/2^{+}_{2}, 1/2^{+}$] and [$^{8}{\rm Li}(1^{+})\otimes s_{\Lambda}=5/2^{+}_{2}, 7/2^{+}$] were observed at $E_{\Lambda}({\rm no.~2})=1.74\pm0.27^{\rm stat.}\pm0.11^{\rm sys.}~{\rm MeV}$ and $E_{\Lambda}({\rm no.~3})=3.30\pm0.24^{\rm stat.}\pm0.11^{\rm sys.}~{\rm MeV}$, respectively. The $E_{\Lambda}({\rm no.~3})$ is larger than shell model predictions by a few hundred keV, and the difference would indicate that a ${\rm ^{5}He}+t$ structure is more developed for the $3^{+}$ state than those for the $2^{+}$ and $1^{+}$ states in a core nucleus $^{8}{\rm Li}$ as a cluster model calculation suggests., Comment: 5 pages, 3 figures

Published
2021
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6. Sedimentation rates in Kagoshima Bay, Southwestern Japan, using the 210Pb method

Author

Yokota K., Inoue M., Kofuji H., and Maeda H.

Subjects
Physics, QC1-999
Abstract

To understand the pattern of sedimentation rates as fundamental physical parameter of coastal environment, the 210Pb dating method was applied to core samples collected from Kagoshima Bay, Southwestern Japan. The sedimentation rate varied at each location within the bay (0.08–0.30 g·cm−2·y−1), and the rate at the bay-head area was less than that at the centre of the bay. The inventory of ex210Pb has a lower value in the bay-head area. The low ex210Pb inventory at Stn.5' is considered to be due to physical, and chemical conditions in the bay-head area.

Published
2012
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9. Spectroscopy of the neutron-rich hypernucleus $^{7}_{\Lambda}$He from electron scattering

Author

Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The missing mass spectroscopy of the $^{7}_{\Lambda}$He hypernucleus was performed, using the $^{7}$Li$(e,e^{\prime}K^{+})^{7}_{\Lambda}$He reaction at the Thomas Jefferson National Accelerator Facility Hall C. The $\Lambda$ binding energy of the ground state (1/2$^{+}$) was determined with a smaller error than that of the previous measurement, being $B_{\Lambda}$ = 5.55 $\pm$ 0.10(stat.) $\pm$ 0.11(sys.) MeV. The experiment also provided new insight into charge symmetry breaking in p-shell hypernuclear systems. Finally, a peak at $B_{\Lambda}$ = 3.65 $\pm$ 0.20(stat.) $\pm$ 0.11(sys.) MeV was observed and assigned as a mixture of 3/2$^{+}$ and 5/2$^{+}$ states, confirming the "gluelike" behavior of $\Lambda$, which makes an unstable state in $^{6}$He stable against neutron emission., Comment: 6 pages, 4 figures

Published
2016
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10. What makes a cyanobacterial bloom disappear? A review of the abiotic and biotic cyanobacterial bloom loss factors

Author

Harris, T, Reinl, K, Azarderakhsh, M, Berger, S, Berman, M, Bizic, M, Bhattacharya, R, Burnet, S, Cianci-Gaskill, J, Domis, L, Elfferich, I, Ger, K, Grossart, H, Ibelings, B, Ionescu, D, Kouhanestani, Z, Mauch, J, Mcelarney, Y, Nava, V, North, R, Ogashawara, I, Paule-Mercado, M, Soria-Píriz, S, Sun, X, Trout-Haney, J, Weyhenmeyer, G, Yokota, K, Zhan, Q, Harris, Ted D., Reinl, Kaitlin L., Azarderakhsh, Marzi, Berger, Stella A., Berman, Manuel Castro, Bizic, Mina, Bhattacharya, Ruchi, Burnet, Sarah H., Cianci-Gaskill, Jacob A., Domis, Lisette N. de Senerpont, Elfferich, Inge, Ger, K. Ali, Grossart, Hans-Peter F., Ibelings, Bas W., Ionescu, Danny, Kouhanestani, Zohreh Mazaheri, Mauch, Jonas, McElarney, Yvonne R., Nava, Veronica, North, Rebecca L., Ogashawara, Igor, Paule-Mercado, Ma. Cristina A., Soria-Píriz, Sara, Sun, Xinyu, Trout-Haney, Jessica V., Weyhenmeyer, Gesa A., Yokota, Kiyoko, Zhan, Qing, Harris, T, Reinl, K, Azarderakhsh, M, Berger, S, Berman, M, Bizic, M, Bhattacharya, R, Burnet, S, Cianci-Gaskill, J, Domis, L, Elfferich, I, Ger, K, Grossart, H, Ibelings, B, Ionescu, D, Kouhanestani, Z, Mauch, J, Mcelarney, Y, Nava, V, North, R, Ogashawara, I, Paule-Mercado, M, Soria-Píriz, S, Sun, X, Trout-Haney, J, Weyhenmeyer, G, Yokota, K, Zhan, Q, Harris, Ted D., Reinl, Kaitlin L., Azarderakhsh, Marzi, Berger, Stella A., Berman, Manuel Castro, Bizic, Mina, Bhattacharya, Ruchi, Burnet, Sarah H., Cianci-Gaskill, Jacob A., Domis, Lisette N. de Senerpont, Elfferich, Inge, Ger, K. Ali, Grossart, Hans-Peter F., Ibelings, Bas W., Ionescu, Danny, Kouhanestani, Zohreh Mazaheri, Mauch, Jonas, McElarney, Yvonne R., Nava, Veronica, North, Rebecca L., Ogashawara, Igor, Paule-Mercado, Ma. Cristina A., Soria-Píriz, Sara, Sun, Xinyu, Trout-Haney, Jessica V., Weyhenmeyer, Gesa A., Yokota, Kiyoko, and Zhan, Qing

Abstract

Cyanobacterial blooms present substantial challenges to managers and threaten ecological and public health. Although the majority of cyanobacterial bloom research and management focuses on factors that control bloom initiation, duration, toxicity, and geographical extent, relatively little research focuses on the role of loss processes in blooms and how these processes are regulated. Here, we define a loss process in terms of population dynamics as any process that removes cells from a population, thereby decelerating or reducing the development and extent of blooms. We review abiotic (e.g., hydraulic flushing and oxidative stress/UV light) and biotic factors (e.g., allelopathic compounds, infections, grazing, and resting cells/programmed cell death) known to govern bloom loss. We found that the dominant loss processes depend on several system specific factors including cyanobacterial genera-specific traits, in situ physicochemical conditions, and the microbial, phytoplankton, and consumer community composition. We also address loss processes in the context of bloom management and discuss perspectives and challenges in predicting how a changing climate may directly and indirectly affect loss processes on blooms. A deeper understanding of bloom loss processes and their underlying mechanisms may help to mitigate the negative consequences of cyanobacterial blooms and improve current management strategies.

Published
2024

11. High Resolution Spectroscopic Study of $^{10}_{\Lambda}$Be

Author

Gogami, T., Chen, C., Kawama, D., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Baturin, P., Badui, R., Boeglin, W., Bono, J., Brash, E., Carter, P., Chiba, A., Christy, E., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fujii, Y., Fujita, M., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Han, Y., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed. V., Jones, M., Kanda, H., Kaneta, M., Kato, S., Kawai, M., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Margaryan, A., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Qiu, X., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Tang, L., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Ya, L., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.

Subjects
Nuclear Experiment
Abstract

Spectroscopy of a $^{10}_{\Lambda}$Be hypernucleus was carried out at JLab Hall C using the $(e,e^{\prime}K^{+})$ reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of 0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using the $p(e,e^{\prime}K^{+})\Lambda,\Sigma^{0}$ reactions allowed us to determine the energy levels, and the binding energy of the ground state peak (mixture of 1$^{-}$ and 2$^{-}$ states) was obtained to be B$_{\Lambda}$=8.55$\pm$0.07(stat.)$\pm$0.11(sys.) MeV. The result indicates that the ground state energy is shallower than that of an emulsion study by about 0.5 MeV which provides valuable experimental information on charge symmetry breaking effect in the $\Lambda N$ interaction., Comment: 6 figures

Published
2015
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17. The experiments with the High Resolution Kaon Spectrometer at JLab Hall C and the new spectroscopy of ${}^{12}_{\Lambda}\text{B}$ hypernuclei

Author

Tang, L., Chen, C., Gogami, T., Kawama, D., Han, Y., Yuan, L., Matsumura, A., Okayasu, Y., Seva, T., Rodriguez, V. M., Baturin, P., Acha, A., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Badui, R., Baker, O. K., Benmokhtar, F., Boeglin, W., Bono, J., Bosted, P., Brash, E., Carter, P., Carlini, R., Chiba, A., Christy, M. E., Cole, L., Dalton, M. M., Danagoulian, S., Daniel, A., De Leo, R., Dharmawardane, V., Doi, D., Egiyan, K., Elaasar, M., Ent, R., Fenker, H., Fujii, Y., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Gibson, E. F., Gueye, P., Hashimoto, O., Honda, D., Horn, T., Hu, B., Hungerford, Ed V., Jayalath, C., Jones, M., Johnston, K., Kalantarians, N., Kanda, H., Kaneta, M., Kato, F., Kato, S., Kawai, M., Keppel, C., Khanal, H., Kohl, M., Kramer, L., Lan, K. J., Li, Y., Liyanage, A., Luo, W., Mack, D., Maeda, K., Malace, S., Margaryan, A., Marikyan, G., Markowitz, P., Maruta, T., Maruyama, N., Maxwell, V., Millener, D. J., Miyoshi, T., Mkrtchyan, A., Mkrtchyan, H., Motoba, T., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Nomura, H., Nonaka, K., Ohtani, A., Oyamada, M., Perez, N., Petkovic, T., Pochodzalla, J., Qiu, X., Randeniya, S., Raue, B., Reinhold, J., Rivera, R., Roche, J., Samanta, C., Sato, Y., Sawatzky, B., Segbefia, E. K., Schott, D., Shichijo, A., Simicevic, N., Smith, G., Song, Y., Sumihama, M., Tadevosyan, V., Takahashi, T., Taniya, N., Tsukada, K., Tvaskis, V., Veilleux, M., Vulcan, W., Wells, S., Wesselmann, F. R., Wood, S. A., Yamamoto, T., Yan, C., Ye, Z., Yokota, K., Zhamkochyan, S., and Zhu, L.

Subjects
Nuclear Experiment
Abstract

Since the pioneering experiment, E89-009 studying hypernuclear spectroscopy using the $(e,e^{\prime}K^+)$ reaction was completed, two additional experiments, E01-011 and E05-115, were performed at Jefferson Lab. These later experiments used a modified experimental design, the "tilt method", to dramatically suppress the large electromagnetic background, and allowed for a substantial increase in luminosity. Additionally, a new kaon spectrometer, HKS (E01-011), a new electron spectrometer, HES, and a new splitting magnet were added to produce precision, high-resolution hypernuclear spectroscopy. These two experiments, E01-011 and E05-115, resulted in two new data sets, producing sub-MeV energy resolution in the spectra of ${}^{7}_{\Lambda}\text{He}$, ${}^{12}_{\Lambda}\text{B}$ and ${}^{28}_{\Lambda}\text{Al}$ and ${}^{7}_{\Lambda}\text{He}$, ${}^{10}_{\Lambda}\text{Be}$, ${}^{12}_{\Lambda}\text{B}$ and ${}^{52}_{\Lambda}\text{V}$. All three experiments obtained a ${}^{12}_{\Lambda}\text{B}$, spectrum, which is the most characteristic $p$-shell hypernucleus and is commonly used for calibration. Independent analyses of these different experiments demonstrate excellent consistency and provide the clearest level structure to date of this hypernucleus as produced by the $(e,e^{\prime}K^+)$ reaction. This paper presents details of these experiments, and the extraction and analysis of the observed ${}^{12}_{\Lambda}\text{B}$ spectrum.

Published
2014
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18. Direct Measurements of the Lifetime of Heavy Hypernuclei

Author

Qiu, X., Tang, L., Margaryan, A., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Badui, R., Baturin, P., Boeglin, W., Bono, J., Brash, E., Carter, P., Chen, C., Chen, X., Chiba, A., Christy, E., Dalton, M. M., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fenker, H., Fujii, Y., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Gogami, T., Hashimoto, O., Horn, T., Hu, B., Hungerford, E. V., Jones, M., Kanda, H., Kaneta, M., Kawai, M., Kawama, D., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Markowitz, P., Maruta, T., Matsumura, A., Maxwell, V., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S. N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M. I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Reinhold, J., Rodriguez, V. M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F. R., Wood, S. A., Ya, L., Yamamoto, T., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.

Subjects
Nuclear Experiment
Abstract

The lifetime of a Lambda particle embedded in a nucleus (hypernucleus) decreases from that of free Lambda decay due to the opening of the Lambda N to NN weak decay channel. However, it is generally believed that the lifetime of a hypernucleus attains a constant value (saturation) for medium to heavy hypernuclear masses, yet this hypothesis has been difficult to verify. The present paper reports a direct measurement of the lifetime of medium-heavy hypernuclei produced with a photon-beam from Fe, Cu, Ag, and Bi targets. The recoiling hypernuclei were detected by a fission fragment detector using low-pressure multi-wire proportional chambers. The experiment agrees remarkably well with the only previously-measured single-species heavy-hypernucleus lifetime, that of Fe56_Lambda at KEK, and has significantly higher precision. The experiment disagrees with the measured lifetime of an unknown combination of heavy hypernuclei with 180

Published
2012

20. Heat-stable spores of carotenoid-producing Bacillus marisflavi and non-pigmented Bacillus subtilis cooperatively promote growth, quality, and gut microbiota of white-leg shrimp

Author

Nguyen, T.T., primary, Bui, A.T.P., additional, Le, N.T.H., additional, Vo, H.T.N., additional, Nguyen, A.H., additional, Pham, T.D., additional, Hara, T., additional, Yokota, K., additional, Matsutani, M., additional, Takatsuka, Y., additional, and Nguyen, A.T.V., additional

Published
2023
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22. Electrostatic Self-assembly : A New Route Towards Nanostructures

Author

Berret, J. -F., Herve, P., Morvan, M., Yokota, K., Destarac, M., Oberdisse, J., Grillo, I., and Schweins, R.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

During the last 3 years, our group has investigated extensively the complexation mechanism between neutral-polyelectrolyte block copolymers with oppositely charged species. These species are surfactant micelles, multivalent counterions and inorganic nanoparticles. In the three cases, we have established the thermodynamical phase diagram of these systems, and found broad regions where supramolecular aggregates spontaneously form via electrostatic self-assembly. From earlier works, it was suspected that these mixed colloids exhibit a core-shell structure. However, their inner structure was unveiled by us only recently, using a combination of light, neutron and x-ray scattering experiments., Comment: 5 pages, 4 figures, to appear in Institute Laue-Langevin Soft Matter Brochure

Published
2005

23. Direct measurements of the lifetime of medium-heavy hypernuclei

Author

Qiu, X., Tang, L., Chen, C., Margaryan, A., Wood, S.A., Achenbach, P., Ahmidouch, A., Albayrak, I., Androic, D., Asaturyan, A., Asaturyan, R., Ates, O., Badui, R., Baturin, P., Boeglin, W., Bono, J., Brash, E., Carter, P., Chen, X., Chiba, A., Christy, M.E., Dalton, M.M., Danagoulian, S., De Leo, R., Doi, D., Elaasar, M., Ent, R., Fenker, H., Fujii, Y., Furic, M., Gabrielyan, M., Gan, L., Garibaldi, F., Gaskell, D., Gasparian, A., Gogami, T., Hashimoto, O., Horn, T., Hu, B., Hungerford, Ed V., Jones, M., Kanda, H., Kaneta, M., Kawama, D., Khanal, H., Kohl, M., Liyanage, A., Luo, W., Maeda, K., Markowitz, P., Marikyan, G., Maruta, T., Matsumura, A., Maxwell, V., Mkrtchyan, A., Mkrtchyan, H., Nagao, S., Nakamura, S.N., Narayan, A., Neville, C., Niculescu, G., Niculescu, M.I., Nunez, A., Nuruzzaman, Okayasu, Y., Petkovic, T., Pochodzalla, J., Reinhold, J., Rodriguez, V.M., Samanta, C., Sawatzky, B., Seva, T., Shichijo, A., Tadevosyan, V., Taniya, N., Tsukada, K., Veilleux, M., Vulcan, W., Wesselmann, F.R., Yamamoto, T., Ye, Z., Yokota, K., Yuan, L., Zhamkochyan, S., and Zhu, L.

Published
2018
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24. Interactions between Polymers and Nanoparticles : Formation of Supermicellar Hybrid Aggregates

Author

Berret, J. -F., Yokota, K., and Morvan, M.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

When polyelectrolyte-neutral block copolymers are mixed in solutions to oppositely charged species (e.g. surfactant micelles, macromolecules, proteins etc), there is the formation of stable supermicellar aggregates combining both components. The resulting colloidal complexes exhibit a core-shell structure and the mechanism yielding to their formation is electrostatic self-assembly. In this contribution, we report on the structural properties of supermicellar aggregates made from yttrium-based inorganic nanoparticles (radius 2 nm) and polyelectrolyte-neutral block copolymers in aqueous solutions. The yttrium hydroxyacetate particles were chosen as a model system for inorganic colloids, and also for their use in industrial applications as precursors for ceramic and opto-electronic materials. The copolymers placed under scrutiny are the water soluble and asymmetric poly(sodium acrylate)poly(acrylamide) diblocks. Using static and dynamical light scattering experiments, we demonstrate the analogy between surfactant micelles and nanoparticles in the complexation phenomenon with oppositely charged polymers. We also determine the sizes and the aggregation numbers of the hybrid organic-inorganic complexes. Several additional properties are discussed, such as the remarkable stability of the hybrid aggregates and the dependence of their sizes on the mixing conditions., Comment: 26 pages, 7 figures, 1 table

Published
2004
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25. Stabilization and Controlled Association of Inorganic Nanoparticles using Block Copolymers

Author

Yokota, K., Morvan, M., Berret, J. -F., and Oberdisse, J.

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

We report on the structural properties of mixed aggregates made from rare-earth inorganic nanoparticles (radius 20 Angstroms) and polyelectrolyte-neutral block copolymers in aqueous solutions. Using scattering experiments and Monte Carlo simulations, we show that these mixed aggregates have a hierarchical core-shell microstructure. The core is made of densely packed nanoparticles and it is surrounded by a corona of neutral chains. This microstructure results from a process of controlled association and confers to the hybrid aggregates a remarkable colloidal stability., Comment: 14 pages, 5 figures

Published
2004
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32. Widespread deoxygenation of temperate lakes

Author

Jane, S, Hansen, G, Kraemer, B, Leavitt, P, Mincer, J, North, R, Pilla, R, Stetler, J, Williamson, C, Woolway, R, Arvola, L, Chandra, S, Degasperi, C, Diemer, L, Dunalska, J, Erina, O, Flaim, G, Grossart, H, Hambright, K, Hein, C, Hejzlar, J, Janus, L, Jenny, J, Jones, J, Knoll, L, Leoni, B, Mackay, E, Matsuzaki, S, Mcbride, C, Muller-Navarra, D, Paterson, A, Pierson, D, Rogora, M, Rusak, J, Sadro, S, Saulnier-Talbot, E, Schmid, M, Sommaruga, R, Thiery, W, Verburg, P, Weathers, K, Weyhenmeyer, G, Yokota, K, Rose, K, Jane S. F., Hansen G. J. A., Kraemer B. M., Leavitt P. R., Mincer J. L., North R. L., Pilla R. M., Stetler J. T., Williamson C. E., Woolway R. I., Arvola L., Chandra S., DeGasperi C. L., Diemer L., Dunalska J., Erina O., Flaim G., Grossart H. -P., Hambright K. D., Hein C., Hejzlar J., Janus L. L., Jenny J. -P., Jones J. R., Knoll L. B., Leoni B., Mackay E., Matsuzaki S. -I. S., McBride C., Muller-Navarra D. C., Paterson A. M., Pierson D., Rogora M., Rusak J. A., Sadro S., Saulnier-Talbot E., Schmid M., Sommaruga R., Thiery W., Verburg P., Weathers K. C., Weyhenmeyer G. A., Yokota K., Rose K. C., Jane, S, Hansen, G, Kraemer, B, Leavitt, P, Mincer, J, North, R, Pilla, R, Stetler, J, Williamson, C, Woolway, R, Arvola, L, Chandra, S, Degasperi, C, Diemer, L, Dunalska, J, Erina, O, Flaim, G, Grossart, H, Hambright, K, Hein, C, Hejzlar, J, Janus, L, Jenny, J, Jones, J, Knoll, L, Leoni, B, Mackay, E, Matsuzaki, S, Mcbride, C, Muller-Navarra, D, Paterson, A, Pierson, D, Rogora, M, Rusak, J, Sadro, S, Saulnier-Talbot, E, Schmid, M, Sommaruga, R, Thiery, W, Verburg, P, Weathers, K, Weyhenmeyer, G, Yokota, K, Rose, K, Jane S. F., Hansen G. J. A., Kraemer B. M., Leavitt P. R., Mincer J. L., North R. L., Pilla R. M., Stetler J. T., Williamson C. E., Woolway R. I., Arvola L., Chandra S., DeGasperi C. L., Diemer L., Dunalska J., Erina O., Flaim G., Grossart H. -P., Hambright K. D., Hein C., Hejzlar J., Janus L. L., Jenny J. -P., Jones J. R., Knoll L. B., Leoni B., Mackay E., Matsuzaki S. -I. S., McBride C., Muller-Navarra D. C., Paterson A. M., Pierson D., Rogora M., Rusak J. A., Sadro S., Saulnier-Talbot E., Schmid M., Sommaruga R., Thiery W., Verburg P., Weathers K. C., Weyhenmeyer G. A., Yokota K., and Rose K. C.

Abstract

The concentration of dissolved oxygen in aquatic systems helps to regulate biodiversity1,2, nutrient biogeochemistry3, greenhouse gas emissions4, and the quality of drinking water5. The long-term declines in dissolved oxygen concentrations in coastal and ocean waters have been linked to climate warming and human activity6,7, but little is known about the changes in dissolved oxygen concentrations in lakes. Although the solubility of dissolved oxygen decreases with increasing water temperatures, long-term lake trajectories are difficult to predict. Oxygen losses in warming lakes may be amplified by enhanced decomposition and stronger thermal stratification8,9 or oxygen may increase as a result of enhanced primary production10. Here we analyse a combined total of 45,148 dissolved oxygen and temperature profiles and calculate trends for 393 temperate lakes that span 1941 to 2017. We find that a decline in dissolved oxygen is widespread in surface and deep-water habitats. The decline in surface waters is primarily associated with reduced solubility under warmer water temperatures, although dissolved oxygen in surface waters increased in a subset of highly productive warming lakes, probably owing to increasing production of phytoplankton. By contrast, the decline in deep waters is associated with stronger thermal stratification and loss of water clarity, but not with changes in gas solubility. Our results suggest that climate change and declining water clarity have altered the physical and chemical environment of lakes. Declines in dissolved oxygen in freshwater are 2.75 to 9.3 times greater than observed in the world’s oceans6,7 and could threaten essential lake ecosystem services2,3,5,11.

Published
2021

40. UTTORI United: Cooperative Team Play Based on Communication

Author

Yokota, K., Ozaki, K., Watanabe, N., Matsumoto, A., Koyama, D., Ishikawa, T., Kawabata, K., Kaetsu, H., Asama, H., Goos, G., editor, Hartmanis, J., editor, van Leeuwen, J., editor, Carbonell, Jaime G., editor, Siekmann, Jörg, editor, Asada, Minoru, editor, and Kitano, Hiroaki, editor

Published
1999
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