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817 results on '"Igarashi, Makoto"'

1. Far-East Asian Toxoplasma isolates share ancestry with North and South/Central American recombinant lineages

Author

Ihara, Fumiaki, Kyan, Hisako, Takashima, Yasuhiro, Ono, Fumiko, Hayashi, Kei, Matsuo, Tomohide, Igarashi, Makoto, Nishikawa, Yoshifumi, Hikosaka, Kenji, Sakamoto, Hirokazu, Nakamura, Shota, Motooka, Daisuke, Yamauchi, Kiyoshi, Ichikawa-Seki, Madoka, Fukumoto, Shinya, Sasaki, Motoki, Ikadai, Hiromi, Kusakisako, Kodai, Ohari, Yuma, Yoshida, Ayako, Sasai, Miwa, Grigg, Michael E., and Yamamoto, Masahiro

Published
2024
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5. Development of deformational regimes and microstructures in the deep sections and overall layered structures of the Dome Fuji ice core, Antarctica

Author

Saruya, Tomotaka, primary, Miyamoto, Atsushi, additional, Fujita, Shuji, additional, Goto-Azuma, Kumiko, additional, Hirabayashi, Motohiro, additional, Hori, Akira, additional, Igarashi, Makoto, additional, Iizuka, Yoshinori, additional, Kameda, Takao, additional, Ohno, Hiroshi, additional, Shigeyama, Wataru, additional, and Tsutaki, Shun, additional

Published
2024
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6. An Antarctic ice core recording both supernovae and solar cycles

Author

Motizuki, Yuko, Takahashi, Kazuya, Makishima, Kazuo, Bamba, Aya, Nakai, Yoichi, Yano, Yasushige, Igarashi, Makoto, Motoyama, Hideaki, Kamiyama, Kokichi, Suzuki, Keisuke, and Imamura, Takashi

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics, Physics - Atmospheric and Oceanic Physics, Physics - Geophysics
Abstract

Ice cores are known to be rich in information regarding past climates, and the possibility that they record astronomical phenomena has also been discussed. Rood et al. were the first to suggest, in 1979, that nitrate ion (NO3-) concentration spikes observed in the depth profile of a South Pole ice core might correlate with the known historical supernovae (SNe), Tycho (AD 1572), Kepler (AD 1604), and SN 1181 (AD 1181). Their findings, however, were not supported by subsequent examinations by different groups using different ice cores, and the results have remained controversial and confusing. Here we present a precision analysis of an ice core drilled in 2001 at Dome Fuji station in Antarctica. It revealed highly significant three NO3- spikes dating from the 10th to the 11th century. Two of them are coincident with SN 1006 (AD 1006) and the Crab Nebula SN (AD 1054), within the uncertainty of our absolute dating based on known volcanic signals. Moreover, by applying time-series analyses to the measured NO3- concentration variations, we discovered very clear evidence of an 11-year periodicity that can be explained by solar modulation. This is one of the first times that a distinct 11-year solar cycle has been observed for a period before the landmark studies of sunspots by Galileo Galilei with his telescope. These findings have significant consequences for the dating of ice cores and galactic SN and solar activity histories., Comment: 18 pages, 5 figures, submitted to Nature; please note that this manuscript is subject to press embargo

Published
2009

10. Development of deformational regimes and microstructures in the deep sections and overall layered structures of the Dome Fuji ice core, Antarctica.

Author

Saruya, Tomotaka, Miyamoto, Atsushi, Fujita, Shuji, Goto-Azuma, Kumiko, Hirabayashi, Motohiro, Hori, Akira, Igarashi, Makoto, Iizuka, Yoshinori, Kameda, Takao, Ohno, Hiroshi, Shigeyama, Wataru, and Tsutaki, Shun

Subjects
ICE cores, ANTARCTIC ice, ICE sheets, SHEAR strain, CRYSTAL orientation
Abstract

An in-depth examination of rheology within the deep sections of polar ice sheets is essential for enhancing our understanding of glacial flow. In this study, we investigate the crystalline textural properties of the 3035-m-long Antarctic deep ice core, with a particular emphasis on its lowermost 20 %. We examine the crystal orientation fabric (COF) and compare it with various other properties from the ice core. In the uppermost approximately 80 % thickness zone (UP80 %), the clustering strength of single pole COF steadily increased, reaching its possible maximum at the bottom of the UP80 %. Below 1800 m in the UP80 %, layers with more or fewer dusty impurities exhibit slower or faster growth of cluster strength. This situation continued until 2650 m. In the remaining lowermost approximately 20 % thickness zone (LO20 %), the trend of the COF clustering strength changed around 2650 m and exhibited substantial fluctuations below this depth. In more impurity-rich layers, stronger clustering is maintained. In impurity-poor layers, relaxation of the COF clustering occurred due to the emergence of new crystal grains with c -axis orientation distinctly offset from the existing cluster, and dynamic recrystallization related to this emergence. The less impure layers show apparent features of bulging and migrating grain boundaries. We argue that the substantial deformational regime of polar ice sheets involves dislocation creep in both UP80 % and LO20 %, with dynamic recrystallization playing a critical role in the LO20 %, particularly in impurity-poor layers, to recover a potential of COF available for the continuation of dislocation-creep-based deformation. Furthermore, we observe that layers and cluster axes of COF rotate meridionally due to rigid-body rotation caused by simple shear strain above subglacial slopes. These features provide vital clues for the development of the 3D structure of polar ice sheets in the deeper part, leading to inhomogeneous deformation between layers in various thickness scales, and the formation of folds, faults and mixing depending on the layers. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Molecular survey of Babesia, Theileria, Trypanosoma, and Anaplasma infections in camels (Camelus dromedaries) in Egyp

Author

Salman, Doaa, Sivakumar, Thillaiampalam, Otgonsuren, Davaajav, Mahmoud, Motamed Elsayed, Elmahallawy, Ehab Kotb, Khalphallah, Arafat, Kounour, Ahmed M.E.Y., Bayomi, Sara A., Igarashi, Makoto, Yokoyama, Naoaki, Salman, Doaa, Sivakumar, Thillaiampalam, Otgonsuren, Davaajav, Mahmoud, Motamed Elsayed, Elmahallawy, Ehab Kotb, Khalphallah, Arafat, Kounour, Ahmed M.E.Y., Bayomi, Sara A., Igarashi, Makoto, and Yokoyama, Naoaki

Abstract

application/pdf, The one-humped camel (Camelus dromedarius) or dromedary is an economically important domestic animal. However, infectious diseases, including those caused by vector-borne hemopathogens, frequently compromise the health and production of camels. In this study, we examined infections caused by Babesia, Theileria, Trypanosoma, and Anaplasma species in camels in Egypt. We analyzed blood DNA samples from 148 camels reared in six Egyptian governorates (Giza, Asyut, Sohag, Qena, Luxor, and the Red Sea) using pathogen-specific Polymerase Chain Reaction (PCR) assays. Our results indicated that 29 (19.6%), 22 (14.9%), 1 (0.7%), 2 (1.4%), 1 (0.7%), 2 (1.4%), and 28 (18.9%) of the surveyed animals were infected with Babesia bovis, B. bigemina, Babesia sp. Mymensingh, Theileria sp. Yokoyama, Theileria equi, Trypanosoma evansi, and Anaplasma marginale, respectively. We found that a total of 68 (45.9%) animals were infected with at least one of the detected hemopathogens. Sequencing analyses of PCR amplicons confirmed our diagnostic results. This study is the first to report Theileria sp. Yokoyama and Babesia sp. Mymensingh in Egypt. This is also the first report of infection with these two species in one-humped camel. In conclusion, this study found that camels in Egypt are infected with several vector-borne hemopathogens, including novel parasite species.

Published
2022

19. Molecular characterization of Cryptosporidium spp. from migratory ducks around Tokachi subprefecture, Hokkaido, Japan

Author

SALAMA, Rehab Youssef, ABDELBASET, Abdelbaset E., TAKEDA, Yohei, IMAI, Kunitoshi, OGAWA, Haruko, and IGARASHI, Makoto

Subjects
Full Paper, Bird Diseases, animal diseases, genotype, Cryptosporidium, Cryptosporidiosis, DNA, Protozoan, Polymerase Chain Reaction, Feces, Ducks, Japan, parasitic diseases, RNA, Ribosomal, 18S, Animals, Parasitology, migratory duck
Abstract

Cryptosporidium, a waterborne protozoan parasite, has a substantial veterinary and medical impact worldwide. This parasite is more often recognized during waterborne outbreaks because of its resistance to chlorine disinfection, small size making it difficult to inactivate/eliminate through filtration, and presence in many animal species including humans. Migratory waterfowl, in addition to acting as mechanical carriers of Cryptosporidium oocysts, can also serve as natural reservoirs of infection by host-specific Cryptosporidium species. For better understanding of the extent of genetic diversity and inter-relationships among avian isolates of Cryptosporidium, 200 fecal samples of migratory ducks from the Tokachi subprefecture, Hokkaido, Japan were collected and analyzed by nested PCR (N-PCR) at the 18S rRNA gene. N-PCR revealed that 11.5% (23/200) were positive for Cryptosporidium spp. Among all samples, sequence analysis identified that 10% (20/200) were 98-100% identical to Cryptosporidium avian genotype III. On the other hand, 1.5% (3/200) were 99-100% identical to C. baileyi. This is the first molecular study reporting the prevalence of Cryptosporidium in migratory ducks in Japan. Genetic diversity among Cryptosporidium isolates from humans and birds has been reported worldwide. Nevertheless, further studies are important to assess genetic variety and to elucidate the transmission dynamics of Cryptosporidium parasites.

Published
2020

20. Seroprevalence of Toxoplasma gondii in Farm Animals in West Kordofan, and Blue Nile states, Sudan

Author

Abdelbaset, E. Abdelbaset, Mossaad, Ehab, Ismail, Ahmed Ali, Ibrahim, Abdalla Mohamed, Xuan, Xuenan, Suganuma, Keisuke, Angara, Tamador E.E., and Igarashi, Makoto

Subjects
parasitic diseases, Camel, Cattle, Goats, Seroprevalence, Sheep, Sudan, Toxoplasma gondii
Abstract

application/pdf, Considering the veterinary and public health significance of T. gondii infection and absence of epidemiological data in West Kordofan, and Blue Nile states in Sudan, a total of 392 serum samples from camel, cattle, sheep and goats in West Kordofan, and Blue Nile states were examined for T. gondii antibodies using Latex agglutination test. The overall seroprevalence was 22.4% (88/392). The seropositivity rate was 13.3% (6/45), 44% (33/75), 61% (22/36), 15.4% (21/136), 6% (6/100) in camels, cattle, sheep and goats and donkeys, respectively. Animal species was the only risk factor of T. gondii seropositivity. The significant higher seroprevalence of T. gondii in sheep and cattle indicates their potential role in the transmission of human toxoplasmosis in Sudan and the widespread contamination of the rural environment in Sudan with Toxoplasma oocysts. Further epidemiological studies, as well as special awareness and educational programs for toxoplasmosis are strongly suggested.

Published
2020

30. Prevalence of toxoplasma gondii and other intestinal parasites in cats in tokachi sub-prefecture, Japan

Author

Salman, Doaa, Pumidonming, Wilawan, Oohashi, Eiji, and Igarashi, Makoto

Subjects
Intestinal parasites, parasitic diseases, Prevalence, Toxoplasma gondii, Cat
Abstract

application/pdf, The present study investigated the prevalence of Toxoplasma gondii and other intestinal parasites in cats in the Tokachi subprefecture in Japan. A total of 365 household cats were included in the study, and 353 serum and 351 fecal samples were collected and analyzed. T. gondii IgG antibodies were detected in the sera of 16.14% of cats based on Latex agglutination test and ELISA. For ELISA, T. gondii RH strain tachyzoites lysate and T. gondii SAG2 recombinant protein were used as antigens. Low seropositivity was detected in cats younger than one year and older than 11 years; outdoor and hunter cats showed significantly high seropositivities. Neutering either in male or female cats, but not gender, had a considerable effect on seroprevalence. Toxoplasma gondii oocysts were detected in one fecal sample. The overall parasitic infestation in cats was 12.5%. Other detected parasites included Toxocara species, which showed the highest prevalence of 7.7%, followed by Isospora spp. (2%), Taenia spp. (1.7%), and Ancylostoma spp. (0.9%). Spirometra spp. was detected in only one sample. Outdoor cats comprised 50% of all 44 parasite-infested cats. Although T. gondii oocysts were detected in only one sample, the relatively high seroprevalence of T. gondii indicated that it can pose significant risks to the environment. Our findings highlighted the potential of outdoor cats as a source of T. gondii and other parasites. © 2018 The Japanese Society of Veterinary Science.

Published
2018

40. Outdoor measurement of multi-junction solar cells and modules based on the reference sunlight method

Author

Suzuki, Mamoru, Nose, Junta, Nakano, Akihiko, Imura, Yoshihiro, and Igarashi, Makoto

Subjects
Solar cells -- Measurement, Earth sciences, Petroleum, energy and mining industries
Abstract

To evaluate the indoor measurement accuracy of multi-junction solar cells and modules experimentally, we have successfully used natural sunlight whose spectral irradiance is close to the reference sunlight. The reference sunlight for evaluating the performance of solar cells can be realized by choosing natural sunlight incident on a sun-facing 37 [degrees] tilted surface at air mass of 1.5, when the atmosphere has turbidity of 0.27, precipitable water of 1.42 cm and so on. The measurement of atmospheric parameters was performed based mainly on the measurement of direct solar spectral irradiance and additionally on the measurements of irradiance and illuminance. In addition, measured values were compared with aerological observation data. The comparison of I-V characteristics measured outdoors and indoors shows that our pulsed-light solar simulator is capable of measuring multi-junction amorphous silicon alloy solar cells and modules accurately enough when its irradiance is set by an amorphous silicon reference cell. This fact is also confirmed by the examination of spectral irradiance on the test plane of the solar simulator. Moreover, we showed that irradiance (or illuminance) can be used instead of atmospheric turbidity and also water vapor content on a surface of the Earth can be used as a rough estimate of precipitable water for finding the reference sunlight conditions.

Published
1997

44. Wee1+-like gene in human cells

Author

Igarashi, Makoto, Nagata, Akihisa, Jinno, Shigeki, Suto, Kimihiko, and Okayama, Hiroto

Subjects
Cell cycle -- Research, Cellular control mechanisms -- Research, Human genetics -- Research, Environmental issues, Science and technology, Zoology and wildlife conservation
Published
1991

45. Repurposing existing drugs: identification of irreversible IMPDH inhibitors by high-throughput screening

Author

Sarwono, Albertus Eka Yudistira, primary, Mitsuhashi, Shinya, additional, Kabir, Mohammad Hazzaz Bin, additional, Shigetomi, Kengo, additional, Okada, Tadashi, additional, Ohsaka, Fumina, additional, Otsuguro, Satoko, additional, Maenaka, Katsumi, additional, Igarashi, Makoto, additional, Kato, Kentaro, additional, and Ubukata, Makoto, additional

Published
2018
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46. Asynchrony between Antarctic temperature and CO2 associated with obliquity over the past 720,000 years

Author

Uemura, Ryu, Motoyama, Hideaki, Masson-delmotte, Valerie, Jouzel, Jean, Kawamura, Kenji, Goto-azuma, Kumiko, Fujita, Shuji, Kuramoto, Takayuki, Hirabayashi, Motohiro, Miyake, Takayuki, Ohno, Hiroshi, Fujita, Koji, Abe-ouchi, Ayako, Iizuka, Yoshinori, Horikawa, Shinichiro, Igarashi, Makoto, Suzuki, Keisuke, Suzuki, Toshitaka, Fujii, Yoshiyuki, Uemura, Ryu, Motoyama, Hideaki, Masson-delmotte, Valerie, Jouzel, Jean, Kawamura, Kenji, Goto-azuma, Kumiko, Fujita, Shuji, Kuramoto, Takayuki, Hirabayashi, Motohiro, Miyake, Takayuki, Ohno, Hiroshi, Fujita, Koji, Abe-ouchi, Ayako, Iizuka, Yoshinori, Horikawa, Shinichiro, Igarashi, Makoto, Suzuki, Keisuke, Suzuki, Toshitaka, and Fujii, Yoshiyuki

Abstract

The delta D temperature proxy in Antarctic ice cores varies in parallel with CO2 through glacial cycles. However, these variables display a puzzling asynchrony. Well-dated records of Southern Ocean temperature will provide crucial information because the Southern Ocean is likely key in regulating CO2 variations. Here, we perform multiple isotopic analyses on an Antarctic ice core and estimate temperature variations at this site and in the oceanic moisture source over the past 720,000 years, which extend the longest records by 300,000 years. Antarctic temperature is affected by large variations in local insolation that are induced by obliquity. At the obliquity periodicity, the Antarctic and ocean temperatures lag annual mean insolation. Further, the magnitude of the phase lag is minimal during low eccentricity periods, suggesting that secular changes in the global carbon cycle and the ocean circulation modulate the phase relationship among temperatures, CO2 and insolation in the obliquity frequency band.

Published
2018
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47. Seroprevalences of Toxoplasma gondii and Neospora caninum in Pet Rabbits in Japan

Author

Salman, Doaa, Oohashi, Eiji, Mohamed, Adel Elsayed Ahmed, Abd, El-Mottelib Abd El-Raheem, Okada, Tadashi, and Igarashi, Makoto

Subjects
seroprevalence, fungi, parasitic diseases, rabbit, Neospora caninum, Toxoplasma gondii
Abstract

application/pdf, The potential contamination of Toxoplasma gondii and Neospora caninum oocysts in the human environment is a concern from the public health viewpoint. However, estimation of their seroprevalences in humans cannot be performed in a manner that distinguishes between oocysts and tissue cysts as a source of infection. Rabbits are considered popular pet animals in Japan that can acquire natural infections by the aforementioned parasites only through the ingestion of oocysts. Therefore, this study was conducted to estimate the seroprevalences of T. gondii and N. caninum in pet rabbits in Japan as an indicator of the possible oocyst contamination in the environment surrounding human beings. Serum samples of 337 rabbits were examined by different serological methods. Enzyme-linked immunosorbent assays were performed to measure the titer of IgG and IgM antibodies. Samples revealed to be seropositive by ELISA were further analyzed by a latex agglutination test, Western blotting and an indirect immunofluorescence assay. The rates of seropositivity for T. gondii were 0.89% (3/337) and 0.29% (1/337) in IgG and IgM ELISA, respectively. SAG1 and SAG2 were detected as major antigens by the positive rabbit sera in Western blotting associated with strong staining observed by IFA in T. gondii tachyzoites. Regarding N. caninum, none of the serum samples showed a specific reaction in both Western blotting and the IFA. The results of this study indicate low seroprevalences of toxoplasmosis and neosporosis in pet rabbits in Japan, suggesting low oocyst contamination in the human environment.

Published
2014

48. Acute hemodynamic response to weightlessness during parabolic flight

Author

Mukai, Chiaki N, Lathers, Claire M, Charles, John B, Bennett, Barbara S, Igarashi, Makoto, and Patel, Saumil

Subjects
Aerospace Medicine
Abstract

The effect of a short exposure to weightlessness on hemodynamic parameters of humans was investigated in seven subjects flown aboard the KC-135 aircraft. Particular attention is given to the relationships among various hemodynamic responses to hypergravic and hypogravic states, observed for four different postures: semisupine, supine, standing, and sitting. Results are presented on changes in the thoracic fluid index, heart rate, cardiac index, and the coefficient of variation of the R-R intervals. High values of the coefficient of variation were found at the onset of 0-G, suggesting that vagal cardiac neural activity increases in all positions except supine (where a small decrease was registered).

Published
1991

49. Repurposing existing drugs: identification of irreversible IMPDH inhibitors by high-throughput screening.

Author

Sarwono, Albertus Eka Yudistira, Mitsuhashi, Shinya, Kabir, Mohammad Hazzaz Bin, Shigetomi, Kengo, Okada, Tadashi, Ohsaka, Fumina, Otsuguro, Satoko, Maenaka, Katsumi, Igarashi, Makoto, Kato, Kentaro, and Ubukata, Makoto

Subjects
INOSINE, LUCIFERASES, SEVERE combined immunodeficiency, INHIBITION (Chemistry), SMALL molecules, CRYPTOSPORIDIUM parvum, CHEMICAL libraries
Abstract

Inosine 5′-monophosphate dehydrogenase (IMPDH) is an essential enzyme for the production of guanine nucleotides. Disruption of IMPDH activity has been explored as a therapeutic strategy for numerous purposes, such as for anticancer, immunosuppression, antiviral, and antimicrobial therapy. In the present study, we established a luciferase-based high-throughput screening system to identify IMPDH inhibitors from our chemical library of known bioactive small molecules. The screening of 1400 compounds resulted in the discovery of three irreversible inhibitors: disulfiram, bronopol, and ebselen. Each compound has a distinct chemical moiety that differs from other reported IMPDH inhibitors. Further evaluation revealed that these compounds are potent inhibitors of IMPDHs with kon values of 0.7 × 104 to 9.3 × 104 M−1·s−1. Both disulfiram and bronopol exerted similar degree of inhibition to protozoan and mammalian IMPDHs. Ebselen showed an intriguing difference in mode of inhibition for different IMPDHs, with reversible and irreversible inhibition to each Cryptosporidium parvum IMPDH and human IMPDH type II, respectively. In the preliminary efficacy experiment against cryptosporidiosis in severe combined immunodeficiency (SCID) mouse, a decrease in the number of oocyst shed was observed upon the oral administration of disulfiram and bronopol, providing an early clinical proof-of-concept for further utilization of these compounds as IMPDH inhibitors. [ABSTRACT FROM AUTHOR]

Published
2019
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50. Asynchrony between Antarctic temperature and CO2 associated with obliquity over the past 720,000 years

Author

Uemura, Ryu, primary, Motoyama, Hideaki, additional, Masson-Delmotte, Valérie, additional, Jouzel, Jean, additional, Kawamura, Kenji, additional, Goto-Azuma, Kumiko, additional, Fujita, Shuji, additional, Kuramoto, Takayuki, additional, Hirabayashi, Motohiro, additional, Miyake, Takayuki, additional, Ohno, Hiroshi, additional, Fujita, Koji, additional, Abe-Ouchi, Ayako, additional, Iizuka, Yoshinori, additional, Horikawa, Shinichiro, additional, Igarashi, Makoto, additional, Suzuki, Keisuke, additional, Suzuki, Toshitaka, additional, and Fujii, Yoshiyuki, additional

Published
2018
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