195 research outputs found
Field surveys of September 2018 landslide-generated waves in the Apporo dam reservoir, Japan:Combined hazard from the concurrent occurrences of a typhoon and an earthquake
We report and analyze a case study of landslide-generated waves that occurred in the Apporo dam reservoir (Hokkaido, Japan) culminating from the rare incident of hazard combination from the September 2018 Typhoon Jebi and Hokkaido earthquake (Mw 6.6 on 5 September 2018). The typhoon and earthquake were concurrent and produced thousands of landslides in the area by the combined effects of soil saturation and ground acceleration. Here, we report the results of our field surveys of the landslides that occurred around the Apporo dam and generated damaging waves in the reservoir. We identified six landslides at a close distance to the dam body; the largest one has a length of 330 m, a maximum width of 140 m and a volume of 71,400 m3. We measured wave runup at a single point with height of 5.3 m for the landslide-generated wave in the reservoir and recorded the damage made to the revetments at the reservoir banks. By considering the locations of the landslides and their potential propagation paths, we speculate that possibly three of the six surveyed landslides contributed to the measured wave runup. The surveyed runup was reproduced by inputting landslide parameters into two independent empirical equations; however, other independent empirical relationships failed to reproduce the observed runup. Our field data from the Apporo dam can be used to improve the quality of predictions made by empirical equations and to encourage further research on this topic. In addition, our field data serves as a call for strengthening dams’ safety to landslide-generated waves in reservoirs
Adenovirus-mediated gene delivery restores fertility in congenitally infertile female mice
Oogenesis depends on close interactions between oocytes and granulosa cells. Abnormal signaling between these cell types can result in infertility. However, attempts to manipulate oocyte-granulosa cell interactions have had limited success, likely due to the blood-follicle barrier (BFB), which prevents the penetration of exogenous materials into ovarian follicles. Here, we used adenoviruses (AVs) to manipulate the oocyte-granulosa cell interactions. AVs penetrated the BFB and transduced granulosa cells through ovarian microinjection. Although AVs caused transient inflammation, they did not impair fertility in wild-type mice. Introduction of Kitl-expressing AVs into congenitally infertile KitlSl-t/KitlSl-t mutant mouse ovaries, which contained only primordial follicles because of a lack of Kitl expression, restored fertility through natural mating. The offspring showed no evidence of AV integration and exhibited normal genomic imprinting patterns for imprinted genes. These results demonstrate the usefulness of AVs for manipulating oogenesis and suggest the possibility of gene therapies for human female infertility
High Time-Resolution Monitoring of Free-Tropospheric Sulfur Dioxide and Nitric Acid at the Summit of Mt. Fuji, Japan
This is the first paper that describes the atmospheric sulfur dioxide (SO2) and nitric acid (HNO3) monitored with a good time-resolution at the summit (3,776 m a.s.l.), which is located in the free troposphere, and southeastern foot (1,284 m a.s.l.) of Mt. Fuji. Japan. During the summer of 2012, two analytical systems consisting mainly of a parallel-plate wet denuder and ion chromatograph operated simultaneously at both the sampling sites. All the samples collected at both the sampling sites contained detectable levels of sulfate from gas-phase SO2 while the nitrate from gas-phase HNO3 was detectable in 97.8% of air samples at the southeastern foot and 88.4% at the summit. The average concentrations of SO2 and HNO3 were, respectively, 0.061 ± 0.071 and 0.031 ± 0.020 ppbv at the summit (n = 672), and 0.347 ± 0.425 and 0.146 ± 0.070 ppbv at the southeastern foot (n = 1344) of Mt. Fuji. Both the acidic gases at the southeastern foot and the HNO3 at the summit showed a diurnal pattern with daytime maxima and nighttime minima. Meanwhile, the SO2 at the summit did not show a distinct shift, which indicates the SO2 concentrations at the summit would be principally controlled by the advection of air parcel in the free troposphere
An interplay of NOX1-derived ROS and oxygen determines the spermatogonial stem cell self-renewal efficiency under hypoxia
酸素による活性酸素制御が精子形成に果たす役割を解明 --活性酸素制御の破綻が男性不妊を引き起こす--. 京都大学プレスリリース. 2021-01-15.Reactive oxygen species (ROS) produced by NADPH1 oxidase 1 (NOX1) are thought to drive spermatogonial stem cell (SSC) self-renewal through feed-forward production of ROS by the ROS-BCL6B-NOX1 pathway. Here we report the critical role of oxygen on ROS-induced self-renewal. Cultured SSCs proliferated poorly and lacked BCL6B expression under hypoxia despite increase in mitochondria-derived ROS. Due to lack of ROS amplification under hypoxia, NOX1-derived ROS were significantly reduced, and Nox1-deficient SSCs proliferated poorly under hypoxia but normally under normoxia. NOX1-derived ROS also influenced hypoxic response in vivo because Nox1-deficient undifferentiated spermatogonia showed significantly reduced expression of HIF1A, a master transcription factor for hypoxic response. Hypoxia-induced poor proliferation occurred despite activation of MYC and suppression of CDKN1A by HIF1A, whose deficiency exacerbated self-renewal efficiency. Impaired proliferation of Nox1- or Hif1a-deficient SSCs under hypoxia was rescued by Cdkn1a depletion. Consistent with these observations, Cdkn1a-deficient SSCs proliferated actively only under hypoxia but not under normoxia. On the other hand, chemical suppression of mitochondria-derived ROS or Top1mt mitochondria-specific topoisomerase deficiency did not influence SSC fate, suggesting that NOX1-derived ROS play a more important role in SSCs than mitochondria-derived ROS. These results underscore the importance of ROS origin and oxygen tension on SSC self-renewal
Isolation and characterization of a thermophilic, obligately anaerobic and heterotrophic marine Chloroflexi bacterium from a Chloroflexi dominated microbial community associated with a Japanese shallow hydrothermal system, and proposal for Thermomarinilinea lacunofontalis gen. nov., sp. nov.
A novel marine thermophilic and heterotrophic Anaerolineae bacterium in the phylum Chloroflexi, strain SW7T, was isolated from an in situ colonization system deployed in the main hydrothermal vent of the Taketomi submarine hot spring field located on the southern part of Yaeyama Archipelago, Japan. The microbial community associated with the hydrothermal vent was predominated by thermophilic heterotrophs such as Thermococcaceae and Anaerolineae, and the next dominant population was thermophilic sulfur oxidizers. Both aerobic and anaerobic hydrogenotrophs including methanogens were detected as minor populations. During the culture-dependent viable count analysis in this study, an Anaerolineae strain SW7T was isolated from an enrichment culture at a high dilution rate. Strain SW7T was an obligately anaerobic heterotroph grew with fermentation, and non-motile thin rods 3.5-16.5 μm in length and 0.2 μm in width constituting multicellular filament. Growth was observed between 37-65 ℃ (optimum 60℃), pH 5.5-7.3 (optimum pH 6.0), 0.5-3.5% (w/v) NaCl concentration (optimum 1.0%). Based on physiological and phylogenetic features of a new isolate, we propose a new species representing a novel genus Thermomarinilinea: the type strain of Thermomarinilinea lacunofontalis sp. nov., is SW7T (= JCM15506T = KCTC5908T)
Microbiological Investigation of the Iron-Containing Floculent Mats in Various Deep Sea Environments
Conference abstract (August 14-19, 2011, Goldschmidt 2011 in Prague, Czech Republic)http://www.godac.jamstec.go.jp/darwin/cruise/natsushima/nt10-13_leg2/ehttp://www.godac.jamstec.go.jp/darwin/cruise/yokosuka/yk10-10/
ACTN1 Mutations Cause Congenital Macrothrombocytopenia
Congenital macrothrombocytopenia (CMTP) is a heterogeneous group of rare platelet disorders characterized by a congenital reduction of platelet counts and abnormally large platelets, for which CMTP-causing mutations are only found in approximately half the cases. We herein performed whole-exome sequencing and targeted Sanger sequencing to identify mutations that cause CMTP, in which a dominant mode of transmission had been suspected but for which no known responsible mutations have been documented. In 13 Japanese CMTP-affected pedigrees, we identified six (46%) affected by ACTN1 variants cosegregating with CMTP. In the entire cohort, ACNT1 variants accounted for 5.5% of the dominant forms of CMTP cases and represented the fourth most common cause in Japanese individuals. Individuals with ACTN1 variants presented with moderate macrothrombocytopenia with anisocytosis but were either asymptomatic or had only a modest bleeding tendency. ACTN1 encodes α-actinin-1, a member of the actin-crosslinking protein superfamily that participates in the organization of the cytoskeleton. In vitro transfection experiments in Chinese hamster ovary cells demonstrated that altered α-actinin-1 disrupted the normal actin-based cytoskeletal structure. Moreover, transduction of mouse fetal liver-derived megakaryocytes with disease-associated ACTN1 variants caused a disorganized actin-based cytoskeleton in megakaryocytes, resulting in the production of abnormally large proplatelet tips, which were reduced in number. Our findings provide an insight into the pathogenesis of CMTP
Lung cancer patients with synchronous colon cancer
Lung and colon cancers are two of the most common malignancies, which, in some cases, may develop synchronously. In the present study, the treatment and outcome of patients with synchronous lung and colon cancers were reviewed. During a 76‑month study period, from April 2009 up to July 2016, 17 (0.54%) of 3,102 patients with lung cancer were diagnosed with colon cancer within 1 month. Heavy smoking and obesity were not specific factors in these patients. A total of 9 patients succumbed to lung cancer during the study period. Survival in asymptomatic patients was longer compared with that in symptomatic patients (median survival, 80 vs. 23.2 months, respectively; P=0.007). Although the incidence of synchronous occurrence of these two cancers may be low, particularly in patients diagnosed incidentally, such patients should be treated accordingly. Future genetic and epidemiological studies are required to elucidate the potential connection between lung and colon cancer
Neuroimaging in autism spectrum disorders : 1H-MRS and NIRS study
Using proton magnetic resonance spectroscopy (1H-MRS), we measured chemical metabolites in the left amygdala and the bilateral orbito-frontal cortex (OFC) in children with autism spectrum disorders (ASD). The concentrations of N-acetylaspartate (NAA) in these regions of ASD were significantly decreased compared to those in the control group. In the autistic patients, the NAA concentrations in these regions correlated with their social quotient. These findings suggest the presence of neuronal dysfunction in the amygdala and OFC in ASD. Dysfunction in the amygdala and OFCmay contribute to the pathogenesis of ASD.We performed a near-infrared spectroscopy (NIRS) study to evaluate the mirror neuron system in children with ASD. The concentrations of oxygenated hemoglobin (oxy-Hb) were measured with frontal probes using a 34-channel NIRS machine while the subjects imitated emotional facial expressions. The increments in the concentration of oxy-Hb in the pars opercularis of the inferior frontal gyrus in autistic subjects were significantly lower than those in the controls. However, the concentrations of oxy-Hb in this area were significantly elevated in autistic subjects after they were trained to imitate emotional facial expressions. The results suggest that mirror neurons could be activated by repeated imitation in children with ASD
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