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13. Variation in noble gas isotopic composition of gas samples from the Aegean arc, Greece

Author

Shimizu, A. Sumino, H. Nagao, K. Notsu, K. Mitropoulos, P.

Abstract

In contrast to most other arcs with oceanic plate subduction, the Aegean arc is characterized by continent-continent subduction. Noble gas abundances and isotopic compositions of 45 gas samples have been determined from 6 volcanoes along the arc, 2 islands in the back-arc region and 7 sites in the surrounding areas. The 3/4He ratios of the samples ranged from 0.027RA to 6.2RA (RA denotes the atmospheric 3He/4He ratio of 1.4×10-6), demonstrating that even the maximum 3He/4He ratio in the region is significantly lower than the maximum ratios of most oceanic subduction systems, which are equal to the MORB value of 8±1 RA. Regional variations in the 3He/4He ratio were observed both along and across the arc. The maximum 3He/4He ratio was obtained from Nisyros volcano located in the eastern end of the arc, and the ratio decreased westward possibly reflecting the difference in potential degree of crustal assimilation or the present magmatic activity in each volcano. Across the volcanic arc, the 3He/4He ratio decreased with an increasing distance from the arc front, reaching a low ratio of 0.063RA in Macedonia, which suggested a major contribution of radiogenic helium derived from the continental crust. At Nisyros, a temporal increase in 3He/4He ratio due to ascending subsurface magma was observed after the seismic crisis of 1995-1998 and mantle neon was possibly detected. The maximum 3He/4He ratio (6.2RA) in the Aegean region, which is significantly lower than the MORB value, is not probably due to crustal assimilation at shallow depth or addition of slab-derived helium to MORB-like mantle wedge, but inherent characteristics of the subcontinental lithospheric mantle (SCLM) beneath the Aegean arc. © 2004 Elsevier B.V. All rights reserved.

Published
2005

15. EARTHQUAKE PREDICTION IN THE AREA OF N. EVIA ON THE BASIS OF GROUNDWATER RADON CONCENTRATION CHANGES

Author

Notsu, K. and Κακαβάς, N.

Abstract

Σημαντικές μεταβολές της συγκέντρωσης του Ραδονίου στα υπόγεια νερά, παρατηρήθηκαν στις 29/7/2003, στο σταθμό μέτρησης των Καμμένων Βούρλων. Οι μεταβολές αυτές είναι αποτέλεσμα των προσεισμικών τάσεων που αναπτύσσονται και έχουν σαν αποτέλεσμα τον προσωρινό εμπλουτισμό του υδροφόρου ορίζοντα σε ραδόνιο Για την ύπαρξη των μεταβολών αυτών ενημερώθηκε αμέσως ο ΟΑΣΠ. Στις 3/8/2003 καταγράφηκε, σε διάστημα μερικών ωρών ένας σημαντικός αριθμός σεισμικών δονήσεων στην Βόρεια Εύβοια. Τα επίκεντρα των σεισμικών αυτών δονήσεων τοποθετούνται στην νοητή γραμμή μεταξύ του επίκεντρου του μεγάλου σεισμού της Σκύρου και της θέσης του σταθμού μέτρησης Ραδονίου στα Καμμένα Βούρλα. Δηλαδή στην προέκταση του ρήγματος του Βορείου Αιγαίου. Στις 23/1/2003, παρουσιάστηκαν στον ίδιο σταθμό μέτρησης 3 σημαντικές μεταβολές του Ραδονίου. Ειδοποιήθηκε ο ΟΑΣΠ για επικείμενη σεισμική δραστηριότητα στη Βόρεια Εύβοια. Στις 29 Ιανουαρίου έγιναν πράγματι τρεις σεισμικές δονήσεις με το επίκεντρο τους να ευρίσκεται πολύ κοντά στο σταθμό μέτρησης των Καμμένων Βούρλων. Στις 2/2/2003, παρουσιάστηκε νέα σημαντική μεταβολή του Ραδονίου στον Σταθμό των Καμμένων Βούρλων που επίσης συνοδεύτηκε από σεισμική δόνηση (7/2/2003) με το ίδιο επίκεντρο. Στις 12/2/2003 σε επιστολή που απευθύναμε στην διοίκηση του ΟΑΣΠ, αναφερόταν η έναρξη νέας μεταβολής του Ραδονίου που επίσης κατέληξε σε σεισμική δόνηση με επίκεντρο στην Β. Εύβοια απέναντι από τον σταθμό των Καμμένων Βούρλων. Οι μεταβολές που καταγράφονται στο σύστημα μέτρησης Ραδονίου που είναι τοποθετημένο στην περιοχή των Καμμένων Βούρλων, προηγούνται κατά 4-6 ημέρες, σεισμικών δονήσεων που συνδέονται με την προέκταση του ρήγματος του Β. Αιγαίου προς την Στερεά Ελλάδα και έχουν το επίκεντρο τους στην Β. Εύβοια. Η μέθοδος φαίνεται ότι θα αποτελέσει ένα σημαντικό εργαλείο στην βραχυπρόθεσμη πρόγνωση σεισμικών δονήσεων, σε τοπικό επίπεδο., Significant changes in the groundwater radon concentration, were observed on the 29/7/2003, at Kammena Vourla. The radon concentration changes can be attributed to the temporary enrichment of the groundwater by radon from the surrounding rocks due to the action of stress release or stress accumulation prior an earthquake. EPPO was immediately informed for the existence of these changes. On the 3/8/2003, a significant number of earthquakes in Northern Evia were recorded in an interval of a few hours. The epicentres of the earthquakes were located in the conceivable line between the epicentre of the strong earthquake of Skyros island (July 2001) and the site of the station of radon measurement at Kammena Vourla, on the extension of the Northern Aegean fault. In the 23/1/2003, in the same station, 3 significant changes of radon concentration were measured EPPO was immediately informed for impending seismic activity in Northern Evia. On the 29th of January three earthquakes were recorded. Their epicentres were located in N. Evia, close to the radon measurement, station. On the 2/2/2003, a new significant radon change occurred at Kammena Vourla followed by an earthquake (7/2/2003). In the 12/2/2003 in a letter that we addressed to the EPPO administration, the beginning of a new radon change was reported which also led to an earthquake with the same epicentre. The changes that are recorded in the system of radon measurement of Kammena Vourla are precursors of earthquakes, related to the extension of the N. Aegean fault towards the Sterea Hellas and have their epicentre in N. Evia. It seems that the method can be an important tool for local, short term earthquake prediction.

Published
2004

16. Mineralogy and composition of Kuroko deposits from northeastern Honshu and their possible modern analogues from the Izu-Ogasawara (Bonin) Arc south of Japan: Implications for mode of formation

Author

Glasby, G. P., Iizasa, K., Hannington, M. D., Kubota, H., Notsu, K., Glasby, G. P., Iizasa, K., Hannington, M. D., Kubota, H., and Notsu, K.

Abstract

The Kuroko deposits of NE Honshu are a key type deposit for the study of volcanogenic massive sulfide deposits. However, these deposits have not been studied in detail since the early 1980's and knowledge of their mode of formation is now dated. In this study, we present the analysis of 12 samples of the Kuroko deposits, 12 samples of submarine hydrothermal minerals from the Sunrise deposit and 6 samples from Suiyo Seamount, both of which are located on the Izu-Ogasawara (Bonin) Arc, for 27 elements. For the Kuroko deposit, Cd>Sb>Ag>Pb>Hg>As>Zn>Cu are highly enriched, Au>Te>Bi>Ba>Mo are moderately enriched, In>Tl are somewhat enriched and Fe is not significantly enriched relative to the average continental crust. Within each of these deposits, a similar pattern of element associations is apparent: Zn–Pb with As, Sb, Cd, Ag, Hg, Tl and Au; Fe–Cu–Ba with As, Sb, Ag, Tl, Mo, Te and Au; Si–Ba with Ag and Au; CaSO4. The enrichment of the chalcophilic elements in these deposits is consistent with hydrothermal leaching of these elements from the host rocks which are dominantly rhyolite–dacite in the case of the Kuroko deposits, rhyolite in the case of the Sunrise deposit and dacite–rhyolite in the case of the Suiyo Seamount deposit. However, this pattern of element enrichment is also similar to that observed in fumarolic gas condensates from andesitic volcanoes. This suggests that there may be a significant magmatic contribution to the composition of the hydrothermal fluids responsible for the formation of the Kuroko deposits, although it is not yet possible to quantify the relative contributions of these two sources of elements. The compositional data show that Sunrise and Suiyo Seamount deposits are much closer compositionally to the Kuroko deposits from NE Honshu than are the submarine hydrothermal deposits from the JADE site in the Okinawa Trough which contain, on average, significantly higher concentrations of Pb, Zn, Sb, As and Ag than each of these deposits. In spit

Published
2008
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17. Πρόγνωση σεισμικών δονήσεων στην περιοχή της Βόρειας Εύβοιας με βάση τις μεταβολές της περιεκτικότητας του ραδονίου στα υπόγεια νερά

Author

Μητρόπουλος, Παναγιώτης, Notsu, K., Δελημπάσης, Ν. Δ., Κακαβάς, Ν., Βουδούρης, Π., Μητρόπουλος, Παναγιώτης, Notsu, K., Δελημπάσης, Ν. Δ., Κακαβάς, Ν., and Βουδούρης, Π.

Published
2004

19. Global CO2 emission from volcanic lakes

Author

Perez, N. M., primary, Hernandez, P. A., additional, Padilla, G., additional, Nolasco, D., additional, Barrancos, J., additional, Melian, G., additional, Padron, E., additional, Dionis, S., additional, Calvo, D., additional, Rodriguez, F., additional, Notsu, K., additional, Mori, T., additional, Kusakabe, M., additional, Arpa, M. C., additional, Reniva, P., additional, and Ibarra, M., additional

Published
2011
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21. Μεταβολές της συγκέντρωσης ραδονίου σε υπόγεια νερά πριν από όλες τις σεισμικές δονήσεις (Μ>_ 2.5), από το Σεπτέμβριο 1998 έως τον Ιανουάριο 1999, στην περιοχή του ρήγματος της Αταλάντης = Radon concentration changes in ground water prior all the earthqua

Author

Μητρόπουλος, Παναγιώτης, Notsu, K., Igarashi, G., Mori, T., Δελημπάσης, Ν. Δ., Κακαβάς, Ν., Μητρόπουλος, Παναγιώτης, Notsu, K., Igarashi, G., Mori, T., Δελημπάσης, Ν. Δ., and Κακαβάς, Ν.

Published
2001

31. Diffuse CO2 efflux from Iwojima volcano, Izu-Ogasawara arc, Japan

Author

Notsu, K., Sugiyama, K., Hosoe, M., Uemura, A., Shimoike, Y., Tsunomori, F., Sumino, H., Yamamoto, J., Mori, T., and Hernández, P.A.

Subjects
*VOLCANOES, *LANDFORMS, *ROCK-forming minerals
Abstract

Abstract: Iwojima volcano, located on the southernmost part of the Izu-Ogasawara arc, is characterized by the extrusion of trachyte or trachy andesite lavas and pyroclastic rocks of Holocene and surface thermal manifestations. Small phreatic explosions have been recorded frequently during the last 100 years with the most recent in 1999 and 2001. In order to elucidate the behavior of volcanic volatiles and to assess the potential activity of this volcano, diffuse CO2 efflux, CO2 content and δ 13C–CO2 in soil gas, and soil temperature at 30 cm depth were measured at 272 sites in March 2000, 112 sites in December 2000 and 40 sites in December 2001. We found that high CO2 efflux values, of more than 100 g m−2 day−1, occurred at several locations on Motoyama volcano corresponding with high soil temperatures (more than 60 °C at 30 cm depth) region and with areas where CO2 with magmatic δ 13C was observed. Here, the magmatic δ 13C determined for fumarolic CO2 data ranged from −2‰ to +3‰, which is clearly higher than magmatic gas values (−8‰ to −2‰) typically found in island arc settings around the world. However, this can be explained in terms of carbon-isotope fractionation between calcite and CO2 under subsurface temperature and pressure conditions at Iwojima. A total efflux of CO2 for Iwojima volcano is estimated to be 760 t day−1, with a magmatic contribution of about 450 t day−1. This value is rather high compared with other volcanoes in island arc settings. Since Iwojima has no visible plume, almost all volcanic CO2 is released as diffuse efflux through the volcanic edifice. [Copyright &y& Elsevier]

Published
2005
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33. Reactions of Alkoxyl Derivatives of a Layered Perovskite with Alcohols:  Substitution Reactions on the Interlayer Surface of a Layered Perovskite

Author

Suzuki, H., Notsu, K., Takeda, Y., Sugimoto, W., and Sugahara, Y.

Abstract

Organic derivatives of a layered perovskite compound, HLaNb2O7·xH2O (HLN), with interlayer surfaces possessing n-alkoxyl groups (n-decoxyl and n-propoxyl) have been allowed to react with various alcohols and a diol (ethylene glycol) to form new organic derivatives via substitution reactions. The reaction of an n-propoxyl derivative of HLN with n-decanol leads to the formation of n-decoxyl groups bound to the interlayer surface of the perovskite-like [LaNb2O7] slab. In a similar fashion, the reaction of an n-decoxyl derivative of HLN with 2-propanol results in the formation of an isopropoxyl derivative. The reaction of the n-decoxyl derivative of HLN with tert-butyl alcohol also proceeds, though the reaction is not completed even after 14 days. After the reaction of the n-decoxyl derivative of HLN with ethylene glycol, only one of the two hydroxyl groups in ethylene glycol is reacted, and −OCH2CH2OH groups are present on the interlayer surface. Water is required for proceeding the substitution reaction between the n-propoxyl derivative of HLN and n-decanol, and the reaction mechanism involving hydrolysis of the alkoxyl groups on the interlayer surface and subsequent esterification is proposed.

Published
2003

36. Soil gas CO2, CH4, and H2distribution in and around Las Cañadas caldera, Tenerife, Canary Islands, Spain

Author

Hernández, P, Pérez, N, Salazar, J, Sato, M, Notsu, K, and Wakita, H

Abstract

Diffuse degassing of CO2, CH4and H2was investigated at the surface environment of Cañadas caldera, Canary Islands, during the gas survey carried out in the summer of 1995. Soil CO2concentration varied significantly from atmospheric levels to 30%, while soil CH4and H2contents ranged from 5 to 851ppm and from 0.5 to 620ppm, respectively. Soil CO2, CH4and H2distribution suggests that high diffuse degassing at Cañadas caldera is volcanic-structurally controlled. Anomalous soil H2concentrations were identified at the summit of Teide and outside caldera boundaries, where the most recent eruption of Tenerife Island occurred. δ13C–CO2data showed a magmatic, mixed magmatic–biogenic, and biogenic origin while a biogenic origin is suggested for soil CH4at Cañadas caldera and its surroundings. By coupling the CO2/3He ratio with the 3He/4He ratio of fumarolic gas samples from the summit of Teide, we propose three possible sources for carbon: MORB-type, organic carbon and carbonate.

Published
2000
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37. Superacidity and Catalytic Activity of Sulfated Zirconia

Author

Katada, N., Endo, J.-i., Notsu, K.-i., Yasunobu, N., Naito, N., and Niwa, M.

Abstract

The acidic property of sulfated zirconia, a so-called solid superacid catalyst, was precisely determined by ammonia temperature-programmed desorption with water vapor treatment and theoretical analysis. The desorption peak from the zirconia support was removed by water vapor treatment, and the generation of two types of acid sites was clarified. One kind of acid site is a Lewis type generated on a submonolayer species of the sulfate covering the surface; the surface concentration of the acid site was 0.5 atoms nm-2, and the adsorption heat of ammonia was ca. 200 kJ mol-1. This corresponds to −19 of the H0 function, demonstrating superacidity. The other type of acid sites generated by loading excess sulfate possessed a high concentration (maximum, 2 nm-2), an adsorption heat of ca. 160 kJ mol-1, an H0 of −12, and Brønsted nature. The former was active for the Friedel−Crafts-type alkylation of benzene with benzyl chloride in the liquid phase, and the latter was active for the skeletal isomerization of butane in gas phase.

Published
2000

38. Remote detection of fumarolic gas chemistry at Vulcano, Italy, using an FT-IR spectral radiometer

Author

Mori, T., Notsu, K., Tohjima, Y., Wakita, H., Nuccio, P.M., and Italiano, F.

Abstract

An infrared absorption spectroscopy remote sensing technique was used to determine the SO"2/HCl ratio in fumarolic plumes at Vulcano, Italy. The measurements were made from the southern crater rim of Fossa Grande Crater, about 400 m from the fumarolic area in the crater. Infrared absorption spectra of HCl and SO"2 were observed for four fumaroles a few tens of metres apart using the hot fumarolic surface as an infrared light source. The measured SO"2/HCl ratios in the FA, F47, FW and lower parti of the F21 fumaroles were 4.5-5.4, 3.5, 9.5-11.2 and 5.8 respectively. The SO"2/HCl ratio of the FA fumarole was higher than that of the gas collected directly in the fumarolic vent (SO"2/HCl ratio = 2.9), and was closer to the S"("t"o"t"a"l")/HCl ratio (= 4.6) of the collected gas. Our results show that the SO"2/HCl ratios of two fumaroles only a few tens of metres apart exhibits differences of about twofold. This suggests that this remote monitoring technique is capable of detecting spatial distribution in the SO"2/HCl ratios of volcanic plumes. Because temporal variations in S/Cl ratios can provide precursory signals for volcanic eruptions [1-3], this remote sensing technique can used efficiently for evaluation of volcanic activity.

Published
1995
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40. Copper isotope characteristics of copper-rich minerals from Besshi-type volcanogenic massive sulphide deposits, Japan, determined using a femtosecond LA-MC-ICP-MS.

Author

Ikehata K., Hirata T., Notsu K., Ikehata K., Hirata T., and Notsu K.

Abstract

Measurements were carried out of the Cu isotope ratios of chalcopyrite, secondary malachite and native Cu of metamorphosed Besshi-type volcanogenic massive sulphide deposits from the abandoned Besshi and Mio mines in Japan using femto-second pulsed laser ablation-multiple collector-inductively coupled plasma-mass spectrometry. The delta-65Cu values of chalcopyrite samples from both mines were relatively narrow compared with those of previously reported values from modern submarine hydrothermal deposits at mid-oceanic ridge settings. However, the delta-65Cu values of chalcopyrite are slightly different for the two mines indicating that, although metamorphic re-equilibration may have reduced the original range of Cu isotopes, the pre-metamorphic delta-65Cu characteristics of both mines are generally preserved. The chalcopyrite samples of one deposit may be significantly affected by dissolution during reworking processes after precipitation on the sea floor. Secondary malachite and native Cu have higher delta-65Cu values than chalcopyrite from the same deposit. This variation may be explained in terms of a redox-controlled isotope fractionation at low-temperature conditions during secondary weathering processes involving the preferential incorporation of 65Cu in secondary Cu(II) solutions. Significant negative isotopic fractionations accompanying the reduction of Cu(II) solutions to native Cu may also have occurred., Measurements were carried out of the Cu isotope ratios of chalcopyrite, secondary malachite and native Cu of metamorphosed Besshi-type volcanogenic massive sulphide deposits from the abandoned Besshi and Mio mines in Japan using femto-second pulsed laser ablation-multiple collector-inductively coupled plasma-mass spectrometry. The delta-65Cu values of chalcopyrite samples from both mines were relatively narrow compared with those of previously reported values from modern submarine hydrothermal deposits at mid-oceanic ridge settings. However, the delta-65Cu values of chalcopyrite are slightly different for the two mines indicating that, although metamorphic re-equilibration may have reduced the original range of Cu isotopes, the pre-metamorphic delta-65Cu characteristics of both mines are generally preserved. The chalcopyrite samples of one deposit may be significantly affected by dissolution during reworking processes after precipitation on the sea floor. Secondary malachite and native Cu have higher delta-65Cu values than chalcopyrite from the same deposit. This variation may be explained in terms of a redox-controlled isotope fractionation at low-temperature conditions during secondary weathering processes involving the preferential incorporation of 65Cu in secondary Cu(II) solutions. Significant negative isotopic fractionations accompanying the reduction of Cu(II) solutions to native Cu may also have occurred.

42. The half-life of 41Ca

Author

Mabuchi, H., primary, Takahashi, H., additional, Nakamura, Y., additional, Notsu, K., additional, and Hamaguchi, H., additional

Published
1974
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47. Structural insights into molecular-targeting helix-loop-helix peptide against vascular endothelial growth factor-A.

Author

Michigami M, Notsu K, Kamo M, Hirokawa T, Kinoshita T, Inaka K, Nakase I, and Fujii I

Subjects
Humans, Crystallography, X-Ray, Molecular Dynamics Simulation, Binding Sites, Protein Binding, Amino Acid Sequence, Models, Molecular, Thermodynamics, Vascular Endothelial Growth Factor A metabolism, Vascular Endothelial Growth Factor A chemistry, Helix-Loop-Helix Motifs, Peptides chemistry, Peptides pharmacology, Peptides metabolism
Abstract

Mid-sized binding peptides have recently emerged as a new therapeutic modality. A helix-loop-helix (HLH) peptide was designed as a scaffold for combinatorial peptide libraries. We screened the HLH peptide libraries against human vascular endothelial growth factor-A (VEGF) to generate a peptide, VS42-LR3, which inhibited VEGF/receptor interaction and suppressed tumor growth in a murine xenograft model of human colorectal cancer. Here, we report the first crystal structure of the HLH peptide in a complex with VEGF at high resolution using space-grown protein crystals. The X-ray structural analysis revealed that the monomeric VS42-LR3 adopted an HLH structure and bound to VEGF at the VEGF receptor-binding site. Interestingly, from the site-directed mutagenesis, thermodynamic analysis, and molecular dynamic simulations, it turned out that the loop region in the non-interacting surface to VEGF affected the structural rigidity of the whole HLH to increase the binding affinity. These findings provide valuable insights for the design of more structurally stable and higher affinity mid-sized binding peptides as well as HLH peptides, that could play a crucial role in advancing molecular-targeting therapies., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Co-authors MK and KI are employees of MARUWA Foods and Biosciences, Inc., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Published
2024
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50. Development of a highly sensitive point-of-care test for African swine fever that combines EZ-Fast DNA extraction with LAMP detection: Evaluation using naturally infected swine whole blood samples from Vietnam.

Author

Ngan MT, Thi My Le H, Xuan Dang V, Thi Bich Ngoc T, Phan LV, Thi Hoa N, Quang Lam T, Thi Lan N, Notsu K, Sekiguchi S, Yamazaki Y, and Yamazaki W

Subjects
Swine, Animals, Vietnam, DNA, Viral, Point-of-Care Testing, African Swine Fever diagnosis, African Swine Fever Virus genetics, Swine Diseases
Abstract

Background: While early detection and early containment are key to controlling the African swine fever (ASF) pandemic, the lack of practical testing methods for use in the field are a major barrier to achieving this feat., Objectives: To describe the development of a rapid and sensitive point-of-care test (POCT) for ASF, and its evaluation using swine whole blood samples for field settings., Methods: In total, 89 swine whole blood samples were collected from Vietnamese swine farms and were performed the POCT using a combination of crude DNA extraction and LAMP (loop-mediated isothermal amplification) amplification., Results: The POCT enabled crude DNA to be extracted from swine whole blood samples within 10 min at extremely low cost and with relative ease. The entire POCT required a maximum of 50 min from the beginning of DNA extraction to final judgment. Compared to a conventional real-time PCR detection, the POCT showed a 1 log reduction in detection sensitivity, but comparable diagnostic sensitivity of 100% (56/56) and diagnostic specificity of 100% (33/33). The POCT was quicker and easier to perform and did not require special equipment., Conclusions: This POCT is expected to facilitate early diagnosis and containment of ASF invasion into both regions in which it is endemic and eradicated., (© 2023 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Published
2023
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