• Geophysics and Geophysical Exploration
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• v.6 no.4
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• pp.199-206
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• 2003

Characteristics of the static shift are discussed by comparing the three-dimensional MT inversion with/without static shift parameterization. The galvanic distortion by small-scale shallow feature often leads severe distortion in inverted resistivity structures. The new inversion algorithm is applied to four numerical data sets contaminated by different amount of static shift. In real field data interpretations, we generally do not have any a-priori information about how much the data contains the static shift. In this study, we developed an algorithm for finding both Lagrangian multiplier for smoothness and the trade-off parameter for static shift, simultaneously in 3-D MT inversion. Applications of this inversion routine for the numerical data sets showed quite reasonable estimation of static shift parameters without any a-priori information. The inversion scheme is successfully applied to all the four data sets, even when the static shift does not obey the Gaussian distribution. Allowing the static shift parameters have non-zero degree of freedom to the inversion, we could get more accurate block resistivities as well as static shifts in the data. When inversion does not consider the static shift as inversion parameters (conventional MT inversion), the block resistivities on the surface are modified considerably to match possible static shift. The inhomogeneous blocks on the surface can generate the static shift at low frequencies. By those mechanisms, the conventional 3-D MT inversion can reconstruct the resistivity structures to some extent in the deeper parts even when moderate static shifts are in the data. As frequency increased, however, the galvanic distortion is not frequency independent any more, and thus the conventional inversion failed to fit the apparent resistivity and phase, especially when strong static shift is added. Even in such case, however, reasonable estimation of block resistivity as well as static shift parameters were obtained by 3-D MT inversion with static shift parameterization.

• Journal of Periodontal and Implant Science
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• v.51 no.4
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• pp.226-238
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• 2021

Purpose: Although several reports have described the relationship between periodontal disease and cardiovascular disease, information about the association between periodontal disease and the progression of degenerative aortic stenosis (AS) is lacking. Therefore, we performed a retrospective, single-center, pilot study to provide insight into this potential association. Methods: Data from 45 consecutive patients (19 men; median age, 83 years) with mild or moderate degenerative aortic stenosis were analyzed for a mean observation period of 3.3±1.9 years. The total amount of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis and titers of serum immunoglobulin G (IgG) against periodontal bacteria and high-sensitivity C-reactive protein (hs-CRP) were evaluated. Aortic valve area (AVA), maximal velocity (Vmax), mean pressure gradient (mean PG), and the Doppler velocity index (DVI) were evaluated. The change in each parameter per year ([Parameter_LATEST-Parameter_BASELINE]/Follow-up Years) was calculated from the retrospective follow-up echocardiographic data (baseline vs. the most recently collected data [latest]). Results: No correlation was found between the concentration of periodontopathic bacteria in the saliva and AS status/progression. The anti-P. gingivalis antibody titer in the serum showed a significant positive correlation with AVA and DVI. Additionally, there was a negative correlation between the anti-P. gingivalis IgG antibody titer and mean PG. The hs-CRP concentration showed positive correlations with Vmax and mean PG. Meanwhile, a negative correlation was observed between the anti-P. gingivalis IgG antibody titer and ΔAVA/year and Δmean PG/year. The hs-CRP concentration showed positive correlations with Vmax and mean PG, and it was significantly higher in patients with rapid aortic stenosis progression (ΔAVA/year <-0.1) than in their counterparts. Conclusions: Our results suggest that periodontopathic bacteria such as A. actinomycetemcomitans and P. gingivalis are not directly related to the status/progression of degenerative AS. However, inflammation and a lower immune response may be associated with disease progression.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.71-78
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• 2021

Trapping efficacy of lures obtained by mixing sex pheromone attractants of two or three species in a single dispenser were evaluated in peach and apple orchards for three lepidopteran fruit borers, Grapholita molesta (GM), Carposina sasaki (CS), and Conogethes punctiferalis (CP) which use different chemicals as their sex attractants. In the peach orchard, the trapping efficacy of the mixed lures of GM and CS attractants were reduced for GM trapping, compared with the single GM lure. The population fluctuation patterns of GM were highly correlated between the single lure and all the mixed lures. In the apple orchard, the efficacy of all the mixed lures were not reduced for GM trapping. The trapping efficacy of all the mixed lures for CS trapping were not reduced compared with the CS single lure in both the peach and apple orchards. In the peach orchard, the population fluctuation patterns of CS were highly correlated between the single lure and the mixed lures. The efficacy of the mixed lures for CP trapping could not be determined because of the small number of caught samples. The results indicated that mixed lures could be utilized for monitoring of the annual adult emergence of two species, GM and CS.

• Journal of Radiation Protection and Research
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• v.46 no.1
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• pp.14-23
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• 2021

Background: For radiological protection and control, the International Commission on Radiological Protection (ICRP) provides the nominal risk coefficients related to radiation exposure, which can be extrapolated using the excess relative risk and excess absolute risk obtained from the Life Span Study of atomic bomb survivors in Hiroshima and Nagasaki with the dose and dose-rate effectiveness factor (DDREF). Materials and Methods: Since it is impossible to directly estimate the radiation risk at doses less than approximately 100 mSv only from epidemiological knowledge and data, support from radiation biology is absolutely imperative, and thus, several national and international bodies have advocated the importance of bridging knowledge between biology and epidemiology. Because of the accident at the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station in 2011, the exposure of the public to radiation has become a major concern and it was considered that the estimation of radiation risk should be more realistic to cope with the prevailing radiation exposure situation. Results and Discussion: To discuss the issues from wide aspects related to radiological protection, and to realize bridging knowledge between biology and epidemiology, we have established a research group to develop low-dose and low-dose-rate radiation risk estimation methodology, with the permission of the Japan Health Physics Society. Conclusion: The aim of the research group was to clarify the current situation and issues related to the risk estimation of low-dose and low-dose-rate radiation exposure from the viewpoints of different research fields, such as epidemiology, biology, modeling, and dosimetry, to identify a future strategy and roadmap to elucidate a more realistic estimation of risk against low-dose and low-dose-rate radiation exposure.

• Journal of Gastric Cancer
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• v.21 no.1
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• pp.103-109
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• 2021

Gastric adenocarcinoma of the fundic gland mucosa type (GA-FGM) was proposed as a new variant of gastric adenocarcinoma of the fundic gland type (GA-FG). However, at present, the influence of Helicobacter pylori and the speed of progression and degree of malignancy in GA-FGM remain unclear. Herein, we report the first case of intramucosal GA-FGM that was endoscopically observed before and after H. pylori eradication over 15 years. The lesion showed the same tumor size with no submucosal invasion and a low MIB-1 labeling index 15 years after its detection using endoscopy. The endoscopic morphology changed from 0-IIa before H. pylori eradication to 0-IIa+IIc and then 0-I after H. pylori eradication. These findings suggest that the unaltered tumor size reflects low-grade malignancy and slow growth, and that the endoscopic morphology is influenced by H. pylori eradication.