Publications by authors named "Miyagi I"

Explosive caldera-forming eruptions eject voluminous magma during the gravitational collapse of the roof of the magma chamber. Caldera collapse is known to occur by rapid decompression of a magma chamber at shallow depth, however, the thresholds for magma chamber decompression that promotes caldera collapse have not been tested using examples from actual caldera-forming eruptions. Here, we investigated the processes of magma chamber decompression leading to caldera collapse using two natural examples from Aira and Kikai calderas in southwestern Japan.

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Objectives: : It is unclear whether the increased center of mass lateral shift during gait induced by leg length difference induces lateral instability. The purpose of this study was to investigate the effect of leg length discrepancy (LLD) on dynamic gait stability and the compensatory kinematic and dynamic strategies for this effect by using the extrapolated center of mass and margin of stability.

Methods: : Nineteen healthy male participants walked without insoles (no LLD condition; 0 cm) and with added insoles (LLD condition; 3 cm).

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Cholesterol crystals (CCs) in carotid plaques might be an indicator of vulnerability, although they have not been fully investigated and non-invasive methods of assessment have not been established. This study examines the validity of assessing CCs using dual-energy computed tomography (DECT) that uses X-rays with different tube voltages for imaging, allowing material discrimination. We retrospectively evaluated patients who had undergone preoperative cervical computed tomography angiography and carotid endarterectomy between December 2019 and July 2020.

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Recurring seasonal changes can lead to the evolution of phenological cues. For example, many arthropods undergo photoperiodic diapause, a programmed developmental arrest induced by short autumnal day length. The selective mechanisms that determine the timing of autumnal diapause initiation have not been empirically identified.

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Article Synopsis
  • * The Chiang Mai form (CM form) shows significant differences in body structure, such as abdominal banding patterns and the arrangement of specific crossveins, compared to the previously recognized Lutzia species.
  • * Genetic analysis indicates that while the CM form shares some similarities with other species, it is distinct enough to be classified as a new species based on both physical traits and genetic data.
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Inhibition of poly(ADP-ribose) polymerase 1 (PARP1) is one of the most promising strategies for cancer chemotherapy, and a number of inhibitors possessing nicotinamide-like structures are being developed. To discover new types of PARP1 inhibitors, we screened a large number of substances of plant origin and isolated two inhibitory substances from the leaves of Syzygium samarangense (Blume) Merrill & L.M.

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Biological studies of Anopheles saperoi were conducted using larval and adult mosquito collections in the northern part of Okinawajima of the Ryukyu Archipelago from June 2009 to July 2010. Anopheles saperoi was the most collected species in the northern Okinawajima, except Motobu Peninsula, where it was not collected. The southern distribution of An.

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To know the blood meal in the stomach of Uranotaenia species, blood-fed mosquitoes were collected by 4 methods at different sites in the mountain forest of 3 islands, Amamioshima, Okinawajima, and Iriomotejima in the Ryukyu Archipelago, Japan from 2005 to 2012. One hundred twenty-four blood-fed Uranotaenia mosquitoes of 7 species (Ur. jacksoni, nivipleura, ohamai, yaeyamana, annandalei, lateralis, and macfarlanei) were collected.

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We describe and illustrate for the 1st time the pupa and larva of adult female Ficalbia ichiromiyagii based on specimens collected from a swamp forest in Otomi, Iriomote Island, Ryukyu Archipelago, Japan. The pupa has a trumpet that is 6.25 times its breadth at halfway, with a long meatal cleft line; setae 6-I, II considerably long, usually single or bifid; median caudal seta absent; and paddle edge serrated only on the outer apical half.

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The bionomics of the mud lobster-hole mosquito Aedes (Geoskusea) baisasi in the Ryukyu Archipelago, Japan, was studied in the field and in the laboratory. The studies included the natural habitat, seasonal appearance, flight activity, mating behavior, resistance of eggs to desiccation, and breeding periods of the immature stages of this species. The burrow systems made by the mud lobster Thalassina anomala were excellent as breeding and resting habitats for both the immature and adult stages of the mosquito.

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During an 11-year study period (1999-2010) on the islands of the Ryukyu Archipelago, Japan, 20 mosquito species were identified. The results revealed new records of species hitherto not reported on these islands. This contribution updates the mosquito fauna of the various islands of the Ryukyu Archipelago.

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Article Synopsis
  • Researchers analyzed 509 mosquitoes from 9 species on Ishigaki and Iriomote islands in Japan's Yaeyama Archipelago for avian Plasmodium prevalence.
  • They found two identical avian Plasmodium lineages in Culex (Culiciomyia) nigropunctatus, which were distinct from those in mainland Japan.
  • This marks the first detection of avian Plasmodium DNA in mosquitoes in this region, suggesting that local resident birds may be infected and that C. nigropunctatus could serve as the primary mosquito vector.
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Silicon is rich in the normal human aorta but decreases with age and the development of atherosclerosis. We hypothesized that soluble silica (Si) and coral sand (CS), as a natural Si-containing material, would suppress high blood pressure (BP) in spontaneously hypertensive rats (SHRs), and clarify the observed antihypertensive mechanism by cell cultures by quantifying messenger RNA expressions in the aorta. In SHR fed diets containing 1% Ca supplemented with CaCO(3) as the control (CT) and CS in a Ca-deficient diet and containing 50 mg/kg Si in the CT diet for 8 weeks, systolic BP was significantly (P < .

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Internal transcribed spacer regions of ribosomal DNA were sequenced, and new species-specific primers were designed to simplify the molecular identification of five morphologically related subgenus Stegomyia mosquito species--Aedes aegypti, Ae. albopictus, Ae. riversi, Ae.

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Objective: In our previous study to evaluate the effects of soluble silicon (Si) on bone metabolism, Si and coral sand (CS) as a natural Si-containing material suppressed peroxisome proliferator-activated receptor γ (PPARγ), which regulates both glucose and bone metabolism and increases adipogenesis at the expense of osteogenesis, leading to bone loss. In this study, we investigated the anti-diabetic effects of bone-seeking elements, Si and stable strontium (Sr), and CS as a natural material containing these elements using obese diabetic KKAy mice.

Methods: Weanling male mice were fed diets containing 1% Ca supplemented with CaCO(3) as the control and CS, and diets supplemented with 50 ppm Si or 750 ppm Sr to control diet for 56 d.

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Article Synopsis
  • * Our results show that the four subspecies of Ae. japonicus are genetically distinct but form a monophyletic group that includes Ae. koreicus, suggesting a need for a reevaluation of their taxonomic classification.
  • * We also developed a DNA-based rapid assay to differentiate Ae. koreicus from potentially confusing species in the U.S., due to their roles as vectors for important viral encephalitides, especially considering the overlap in their distributions.
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A colony of Uranotaenia macfarlanei, a frog-feeding mosquito, was established in the laboratory. We report the bionomics of the species, as studied in the laboratory colony and in the field on Ryukyu Island, Japan. These include mating activity, feeding and resting habits, manner of oviposition, and egg, larval, and pupal periods.

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The cyclopentenonic prostaglandin 15-deoxy-Delta(12,14)-PG J(2) (15d-PGJ(2)) is a metabolite derived from PGD(2). Although 15d-PGJ(2) has been demonstrated to be a potent ligand for peroxisome proliferator activated receptor gamma (PPARgamma), the functions are not fully understood. In order to examine the effect of 15d-PGJ(2) on histone acetyltransferases (HATs), several lines of cell including mouse embryonic fibroblast (MEF) cells were exposed to 15d-PGJ(2).

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Objective: The effects of five calcium (Ca) sources were compared for bone biochemical and mechanical properties and the related gene expression using mice, from the viewpoint of their soluble silicon (Si) content.

Methods: Weanling male mice were fed diets containing 1% Ca supplemented with CaCO(3) as the control (CT), coral sand (CS), fossil stony coral (FSC), fish bone (FC) and eggshell (EC) powders, and 50 ppm of Si in the CT diet for 6 mo. The mRNA expressions related to bone remodeling were quantified by real-time polymerase chain reaction.

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Silicon has been known as an essential element for bone formation. The silicon contents of sea water increase with increasing of depth: 1.8 ppm Si in deep-sea water (DW) at 612 m in depth versus 0.

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Fibrinogen is a large plasma glycoprotein with a molecular mass of 340kDa that plays a critical role in the final stage of blood coagulation. Human plasma fibrinogen is a dimeric molecule comprising two sets of three different polypeptides (Aalpha, 66kDa; Bbeta, 55kDa; gamma, 48kDa). To express recombinant human fibrinogen in the methylotrophic yeast Pichia pastoris, we constructed an expression vector containing three individual fibrinogen chain cDNAs under the control of the mutated AOX2 (mAOX2) promoter.

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During a mosquito survey in Ulu Gombak, Selangor, Peninsular Malaysia, October 2-16, 2003, we observed a peculiar oviposition habit of Armigeres flavus. This strange behavior is described and illustrated with photographs; although it is well known, no detailed description has been made previously.

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Mosquito collections were carried out in August 2002 and July 2003 in Japan. Anopheles sinensis of the Hyrcanus Group, Myzomyia Series of Anopheles, was the most common species encountered. The distribution and habitats of 5 Anopheles Hyrcanus Group species are included.

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Nonalcoholic fatty liver disease (NAFLD) is one of the most frequent causes of abnormal liver dysfunction, and its prevalence has markedly increased; however, the mechanisms involved in the pathogenesis of NAFLD have not been thoroughly investigated in humans. In this study, we evaluated the expression of fatty acid metabolism-related genes in NAFLD. Real-time RT-PCR was performed using liver biopsy samples from 12 NAFLD patients.

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Six mark-release-recapture experiments with Anopheles saperoi Bohart and Ingram were performed in the Yona Forest, northern Okinawa, Japan from June 1998 - November 1999, in order to estimate the gonotrophic cycle, survival, spatial distribution, flight range, and population size of An. saperoi. Adults and immature An.

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