Integrated Population Genomic Analysis and Numerical Simulation to Estimate Larval Dispersal of Acanthaster cf. solaris Between Ogasawara and Other Japanese Regions

The estimation of larval dispersal on an ecological timescale is significant for conservation of marine species. In 2018, a semi-population outbreak of crown-of-thorns sea star, Acanthaster cf. solaris, was observed on a relatively isolated oceanic island, Ogasawara. The aim of this study was to assess whether this population outbreak was caused by large-scale larval recruitment (termed secondary outbreak) from the Kuroshio region. We estimated larval dispersal of the coral predator A. cf. solaris between the Kuroshio and Ogasawara regions using both population genomic analysis and simulation of oceanographic dispersal. Population genomic analysis revealed overall genetically homogenized patterns among Ogasawara and other Japanese populations, suggesting that the origin of the populations in the two regions is the same. In contrast, a simulation of 26-year oceanographic dispersal indicated that larvae are mostly self-seeded in Ogasawara populations and have difficulty reaching Ogasawara from the Kuroshio region within one generation. However, a connectivity matrix produced by the larval dispersal simulation assuming a Markov chain indicated gradual larval dispersal migration from the Kuroshio region to Ogasawara in a stepping-stone manner over multiple years. These results suggest that the 2018 outbreak was likely the result of self-seeding, including possible inbreeding (as evidenced by clonemate analysis), as large-scale larval dispersal from the Kurishio population to the Ogasawara population within one generation is unlikely. Instead, the population in Ogasawara is basically sustained by self-seedings, and the outbreak in 2018 was also most likely caused by successful self-seedings including possible inbreeding, as evidenced by clonemate analysis. This study also highlighted the importance of using both genomic and oceanographic methods to estimate larval dispersal, which provides significant insight into larval dispersal that occurs on ecological and evolutionary timescales.

Regional and sex differences in retinal detachment surgery: Japan-retinal detachment registry report

It is known that social factors affect the choice of treatments, and special attention has been paid to sex differences. The purpose of this study was to determine whether regional and sex differences exist in the treatment of rhegmatogenous retinal detachment (RD). We used Japan-RD Registry database of 2523 patients aged ≥ 40 years between February 2016 and March 2017 in 5 Japanese regions. Regional differences of patients’ perioperative factors were analyzed. The factors affecting the proportion of patients who underwent surgery within one week of the onset, defined as early-surgery, were examined by logistic regression. We observed regional differences in perioperative factors, especially in the use of phacovitrectomy, general anesthesia, and air-tamponade, which was higher in certain regions. (Fisher’s exact test, all P = 0.012) The proportion of early-surgery was significantly higher among men in Kyushu region (Odds ratio (OR) 1.83; 95% confidence interval (CI) 1.08–3.12; P = 0.02), and it was also significantly higher after adjusting for covariates (OR 1.89; 95% CI 1.06–3.42; P = 0.02). Regional and sex differences exist in the treatment of RD in Japan. Although there was no significant differences in the anatomical outcomes, women in certain regions of Japan are less likely to receive early surgical intervention for RD.

Coupled investigations of ionosphere variations over European and Japanese regions: observations, comparative analysis, and validation of models and facilities

This paper presents the results of a coordinated measurement campaign with ground based and satellite observations over European and Japanese regions during September 5–6, 2017. Two incoherent scatter radars, two satellite missions, International Reference Ionosphere (IRI-2016) empirical model, and Field Line Interhemispheric Plasma (FLIP) physical model were employed to examine the regular behavior of the F2-layer peak height and density and the topside ionosphere electron density, electron, and ion temperatures as well as traveling ionospheric disturbances (TIDs). The daily ionospheric variations over Kharkiv and Shigaraki exhibited similar behavior qualitatively and quantitatively. The results show that none of the empirical IRI-2016 models of F2-layer peak height, topside electron density, and temperature can be preferred for predicting the key qualitative features of variations in ionospheric plasma parameters over Kharkiv and Shigaraki. The likely reason is rapid day to day changes in solar activity and series of moderate enhancements of magnetic activity occurring in the observation period and preceding days. Compared with IRI-2016 model, the FLIP physical model was shown to provide the best agreement with the observations when constrained to follow the observed diurnal variations of F2-layer peak height both over Europe and Japan. This paper presents the first direct comparison of the mid-latitude electron density measured by the Swarm satellite with incoherent scatter radar data and it confirms the high quality of the space-borne data. For the first time, evidence of the possible need to increase the neutral hydrogen density in NRLMSISE-00 model by at least a factor of 2 was obtained for the Asian longitudinal sector. The TIDs, which have predominant periods of about 50 min over Europe and 80 min over Japan, were detected, likely caused by passage of the solar terminator. Such a difference in the periods could indicate regional features and is the topic for further research.

Genetic Structure of the Goniopora lobata and G. djiboutiensis Species Complex Is Better Explained by Oceanography Than by Morphological Characteristics

Species delimitation of closely related corals is often challenging due to high intraspecies morphological variation and phenotypic plasticity with a lack of characteristic features and scarcity of relevant molecular markers. Goniopora spp. are one such coralline group, and the species status of Goniopora lobata and Goniopora djiboutiensis, an Indian and Pacific Ocean hermatypic coral species complex, has been questioned on the basis of previous molecular and morphological analyses. To further examine the species boundaries between G. lobata and G. djiboutiensis in Japan, specimens collected from areas spanning from Ryukyu Island to temperate Japanese regions were morphologically identified based on traditional morphological descriptions. Then, the genetic structure of the G. lobata and G. djiboutiensis species complex was examined using six newly developed microsatellite markers. The majority of the collected specimens had intermediate morphologies, and a STRUCTURE analysis using the LOCPRIOR model based on typical G. lobata and G. djiboutiensis morphology indicated that there were no genetic differences between these morphologies. On the other hand, STRUCTURE analysis based on oceanographic regions revealed that there was a genetic break between the temperate and subtropical regions. This weak genetic break corresponded with the Kuroshio-associated barrier, which prevents larval transport between subtropical and temperate regions. This study confirms that the current morphological identification criteria for G. lobata and G. djiboutiensis do not match the existing genetic boundaries and thus the two should be regarded as a species complex. This study also highlighted the robustness of using a multi-locus population genetic approach, including a geographic context, to confirm the species boundaries of closely related species.

Actual state of “triple therapy” for heart failure patients in eight regions of Japan: An analysis of a nationwide medical claims database

Background This study aimed to collect data on “triple therapy” for heart failure (HF) with angiotensin-converting enzyme inhibitors (or receptor blockers), β-blockers, and mineralocorticoid receptor antagonists in all eight regions of Japan and clarify the reason for the selection of this therapeutic approach. Methods and results We used data from April 2017 to March 2018 from the Medical Data Vision database (380 facilities) to analyze factors impacting triple therapy for HF. Among patients who were hospitalized for HF during the study period, 51,933 patients met the inclusion criteria and underwent further analyses. A reference value of 20.45% from Kanto was used to compare the eight Japanese regions. From the patient cohort, 10,006 (19.27%) patients receiving triple therapy were identified. The highest and lowest rates of triple therapy were in Chugoku (21.90%) and Shikoku (14.27%), respectively, suggesting regional differences in the use of triple therapy at discharge for patients with HF (P < 0.001). Regression analysis revealed a decrease in the administration of triple therapy for patients with chronic kidney disease (odds ratio [OR], 0.45; 95% confidence interval [CI], 0.43–0.48]; P < 0.001), those aged 75 years and older (OR, 0.46, 95% CI: 0.44–0.49; P < 0.001), those from Shikoku (OR, 0.69; 95% CI, 0.60–0.80; P < 0.001), those with chronic obstructive pulmonary disease (OR, 0.75; 95% CI, 0.68–0.84; P < 0.001), those with anemia (OR, 0.78; 95% CI, 0.62–0.98; P = 0.034), and those from Tohoku (OR, 0.83; 95% CI, 0.75–0.92; P < 0.001). Conclusions Future efforts to rectify the regional variance in drug therapy conforming to the guidelines for the treatment of acute and chronic HF will help to extend the healthy lifespans of patients with HF. Further clarification is required to determine instances where triple therapy should be avoided based on patient factors, and appropriate countermeasures should be identified.

Integrated population genomic analysis and numerical simulation to estimate larval dispersal of Acanthaster cf. solaris between Ogasawara and other Japanese regions

The estimation of larval dispersal of marine species occurring on an ecological timescale is significant for conservation. In 2018, a semi-population outbreak of crown of thorns starfish, Acanthaster cf. solaris was observed on a relatively isolated oceanic island, Ogasawara. The aim of this study was to assess whether this population outbreak was caused by large-scale larval recruitment (termed secondary outbreak) from the Kuroshio region. We estimated larval dispersal of the coral predator A. cf. solaris between the Kuroshio and Ogasawara regions using both population genomic analysis and oceanographic dispersal simulation. Population genomic analysis revealed overall genetically homogenized patterns among Ogasawara and other Japanese populations, suggesting that the origin of the populations in the two regions is the same. In contrast, a simulation of 26-year oceanographic dispersal indicated that larvae are mostly self-seeded in Ogasawara populations and have difficulty reaching Ogasawara from the Kuroshio region within one generation. However, a connectivity matrix produced by the larval dispersal simulation assuming a Markov chain indicated gradual larval dispersal migration from the Kuroshio region to Ogasawara in a stepping-stone manner over multiple years. These results suggest that, while large-scale larval dispersal from an outbreak of the Kuroshio population spreading to the Ogasawara population within one generation is unlikely. This study also highlighted the importance of using both genomic and oceanographic methods to estimate larval dispersal, which provides significant insight into larval dispersal that occurs on ecological and evolutionary timescales.

Effectiveness of Social Measures against COVID-19 Outbreaks in Selected Japanese Regions Analyzed by System Dynamic Modeling

In Japan’s response to the coronavirus disease 2019 (COVID-19), virus testing was limited to symptomatic patients due to limited capacity, resulting in uncertainty regarding the spread of infection and the appropriateness of countermeasures. System dynamic modelling, comprised of stock flow and infection modelling, was used to describe regional population dynamics and estimate assumed region-specific transmission rates. The estimated regional transmission rates were then mapped against actual patient data throughout the course of the interventions. This modelling, together with simulation studies, demonstrated the effectiveness of inbound traveler quarantine and resident self-isolation policies and practices. A causal loop approach was taken to link societal factors to infection control measures. This causal loop modelling suggested that the only effective measure against COVID-19 transmission in the Japanese context was intervention in the early stages of the outbreak by national and regional governments, and no social self-strengthening dynamics were demonstrated. These findings may contribute to an understanding of how social resilience to future infectious disease threats can be developed.

Effect of IQOS introduction on cigarette sales: evidence of decline and replacement

BackgroundPhilip Morris International, one of the largest transnational cigarette manufacturers, has heavily invested in its new heated tobacco product, IQOS, marketing it aggressively as a less harmful alternative to cigarette smoking. The company’s assertions that the product replaces cigarettes in a market have never been independently tested. The objective of this study is to determine whether introduction of IQOS affected cigarette sales in a large economy.Data and MethodsUsing 2014 to 2018 monthly retailer panel data from Japan, we analyse whether different dates of IQOS introduction across Japan’s regions are reflected in the patterns of cigarette sales in those regions. A series of placebo models are estimated to test if events other than IQOS introduction could have better explained the observed trends in cigarette sales.ResultsCigarette sales begin to substantially decline at the time of the introduction of IQOS in each of 11 Japanese regions (Chow tests p<0.001). IQOS introduction, which varied across regions, better predicted the timing of cigarette sales decline than any one time applied to all regions simultaneously (a national-level exogenous shock) and than nearly all possible rearrangements of the true IQOS introduction months among the regions (exact permutation test’s p value from 0.02 to 0.13, depending on the study approach).ConclusionsThe introduction of IQOS likely reduced cigarette sales in Japan. The net population health impact, however, cannot be assessed without resolving several key uncertainties related to the direct harms of IQOS and the precise patterns of both smoking and IQOS use.