Sirt1 (member of the sirtuin family) is a nicotinamide adenosine dinucleotide (NAD)-dependent deacetylase that removes acetyl groups from various proteins. Sirt1 performs a wide variety of functions ...in biological systems. The current review focuses on the biological functions of Sirt1 in obesity-associated metabolic diseases, cancer, adipose tissue, aging, cellular senescence, cardiac aging and stress, prion-mediated neurodegeneration, inflammatory signaling in response to environmental stress, development and placental cell survival.
This study presents a new storm surge hazard potential index (SSHPI) for estimating tropical cyclone (TC) induced peak surge levels at a coast. The SSHPI incorporates parameters that are often ...readily available at real-time: intensity in 10-min maximum wind speed, radius of 50-kt wind, translation speed, coastal geometry, and bathymetry information. The inclusion of translation speed and coastal geometry information lead to improvements of the SSHPI to other existing surge indices. A retrospective analysis of SSHPI using data from 1978-2019 in Japan suggests that this index captures historical events reasonably well. In particular, it explains ~ 66% of the observed variance and ~ 74% for those induced by TCs whose landfall intensity was larger than 79-kt. The performance of SSHPI is not sensitive to the type of coastal geometry (open coasts or semi-enclosed bays). Such a prediction methodology can decrease numerical computation requirements, improve public awareness of surge hazards, and may also be useful for communicating surge risk.
In this study, 42 years of tidal records and landfall TC best tracks in Japan were used to demonstrate that TC pre-landfall forward speed is significantly correlated with maximum storm surge height. ...Coastal morphology was the determining factor for the correlation between storm surge and TC forward speed. Fast-moving TCs tended to amplify the storm surge along open coastlines (Pearson correlation coefficient, R = 0.62), but reduce it in semi-enclosed bays (R = −0.52). The negative correlation contrasts with the general perception that the coincidence of TC wind speed and forward speed vectors generates a larger storm surge. The influence of coastal morphology was most prominent for TCs with a central pressure lower than 956 hPa. Tropical cyclone (TC) operational forecasts are continuously improving; however, there is still scope to improve the precision of storm surge predictions. These findings could contribute to the improvement of storm surge forecasting and provide emergency management personnel with more precise early warnings of dangerous storm surges.
Abstract
Variability in storminess, storm surge, and mean sea level (MSL) can substantially alter coastal hazards associated with extreme sea levels (ESLs). However, the detection and attribution of ...the past changes in tropical cyclone (TC) activity and associated storm surges are hampered by the inhomogeneous TC records. In this study, we investigate spatiotemporal changes in storm surge levels in Japan from 1980 to 2019, a period when observational platforms including tide gauges and storm records are highly consistent. We find statistical evidence supporting the increase in surge annual maxima in several places including the bay area of Tokyo since 1980. This rate of change is comparable to that observed for MSL rise over the same period. These findings cast doubt on the current hypothesis underlying the flood adaptation plan, which assumes that future surge extremes will remain the same and only considers MSL changes. We demonstrate that the changes in ESL in the last 40 years cannot be explained by the rise of MSL alone. Rather, the northeastward shifting of TC landfall location along with intensifying and widening of TCs, might have altered the likelihood of ESL, including surge extremes. The substantial influence of these TC meteorological variables on surge levels combined with the rise of MSL, suggests that current coastal planning practices including critical heights for flood defenses might be inadequate in the future.
This study investigated tidal records and landfall tropical cyclone (TC) best tracks from 1980 to 2019 to determine changes in storm surge heights in coastal regions of Central Japan, including ...Tokyo. The results indicate that annual mean storm surge heights have increased in the last 20 years (2000–2019) compared with those in 1980–1999, and that these changes are noteworthy, particularly in Tokyo Bay. The TC wind intensity and size during landfall have become stronger and larger, respectively, corresponding to increasing storm surge magnitudes from 1980 to 2019. The increased frequency of TCs with more northeastward tracks is another factor that may have contributed to the increased surge hazards around Tokyo. Additionally, a positive correlation between surge heights and a hazard index supports these statistical findings. The central coast of Japan will likely experience increasing numbers of extreme storm surge events in the future if the current increasing tendency continues.
Ensemble forecasting is a promising tool to aid in making informed decisions against risks of coastal storm surges. Although tropical cyclone (TC) ensemble forecasts are commonly used in operational ...numerical weather prediction systems, their potential for disaster prediction has not been maximized. Here we present a novel, efficient, and practical method to utilize a large ensemble forecast of 1,000 members to analyze storm surge scenarios toward effective decision making such as evacuation planning and issuing surge warnings. We perform the simulation of TC Hagibis (2019) using the Japan Meteorological Agency's (JMA) nonhydrostatic model. The simulated atmospheric predictions were utilized as inputs for a statistical surge model named the Storm Surge Hazard Potential Index to estimate peak surge heights along the central coast of Japan. We show that Pareto‐optimized solutions from an ensemble storm surge forecast can describe potential worst (maximum) and optimum (minimum) storm surge scenarios. These solutions exemplify a diversity of trade‐off surge outcomes across diverse coastal locations, reflecting variations in coastal geometry, including bathymetry. For example, some of the Pareto‐optimized solutions that illustrate worst surge scenarios for inner bay locations are not necessarily accountable for bringing severe surge cases in open coasts. We further emphasize that an in‐depth evaluation of Pareto‐optimal solutions can shed light on how meteorological variables such as track, intensity, and size of TCs influence the worst and optimum surge scenarios, which is not clearly quantified in current multiscenario assessment methods such as those used by JMA/National Hurricane Center in the United States.
Plain Language Summary
Ensemble forecasting generates multiple predictions of a weather event with various possible outcomes based on varying initial conditions, model parameters, and physics. The potential of ensemble tropical cyclone (TC) forecasting for assessing storm surge multiscenarios has largely been overlooked previously. Enhanced analysis can unlock and maximize the benefit of ensemble forecasting. This study simulated an extremely large ensemble (=1,000 members) to reforecast past TC Hagibis which hit the central coast of Japan in 2019 and utilized the results to predict storm surges. We propose that Pareto‐optimality can identify good ensemble members that reasonably represent potential worst/minimum storm surge scenarios, meaning no other ensemble members can represent better than those. Comprehensive analyses of Pareto‐members can give forecasters and decision makers a better understanding of how the predicted track, wind intensity, and size of a TC can impact the worst and best storm surge scenarios. This type of analysis is expected to improve the planning of evacuations and the issuing of storm surge warnings.
Key Points
The potential of ensemble tropical cyclone forecasting for assessing storm surge multiscenarios is shown
Pareto‐optimized solutions from an ensemble storm surge forecast can efficiently illustrate potential worst and minimum storm surge scenarios
Analyses of meteorological variables of ensemble members in Pareto‐frontiers help understand the impact of a tropical cyclone on predicted storm surge multiscenarios
In recent years, rainfall-induced waterlogging has become a common hazard in the highly urbanized coastal city of Chattogram, Bangladesh, resulting in a high magnitude of property damage and economic ...loss. Therefore, the primary objective of this research was to prepare a waterlogging inventory map and understand the spatial variations of the risk by means of hazard intensity, exposure, and vulnerability of waterlogging. In this research, the inventory map and factors influencing waterlogging hazards were determined from a participatory survey, and other spatial data, including land elevation, population, and structural data, were collected from secondary sources. The analytical hierarchy process was applied to measure the hazard intensity, and the exposure and vulnerability were estimated by overlaying the spatial data onto the hazard intensity map. A total of 58 locations were identified as waterlogging affected, which covered ~8.42% of the city area. We showed that ~3.03% of the city area was greatly vulnerable to waterlogging in terms of their social, infrastructure, critical facilities, economic, and environmental vulnerabilities. The obtained waterlogging risk index map suggested that ~2.71% of the study area was at very high risk, followed by moderate (~0.15%), low (~3.89%), and very low (~1.67%). The risk analysis presented in this study was a simple method that can be applied to assess the relative risk of waterlogging in different regions, and the results were applicable to the prevention and mitigation of waterlogging for Chattogram City.
This study reviews the progress of disaster mitigation measures against tropical cyclones (TCs) in three Asian countries with different historical, social, and economic backgrounds: Bangladesh, ...Vietnam, and Japan. In Bangladesh, an average of 6,600 people was killed by a single TC in the 1960s, but this number had decreased to 30 in the 2010s; this reduction was due to a clear improvement in soft measures, such as weather forecasting, warning systems, and mass evacuation coordinated by volunteers. In Vietnam, several strong TCs have recently made landfall, leading to improvements in national disaster management. Although Vietnam's current disaster management budget is smaller than those of the two other countries, large-scale evacuation by local authorities is believed to have minimized casualties. In Japan, shortly after Typhoon Vera in 1959, a comprehensive law on disaster prevention was enacted, and coastal dikes were constructed nationwide, resulting in a considerable reduction in fatalities due to TCs. However, the disaster prevention facilities built in this period are now deteriorating, while Japan's budget for disaster management is projected to be decreasing. The three countries have advanced their disaster preparedness in response to past TCs and storm surges, but new challenges have also arisen.
In this study, a storm surge model of the semi-enclosed Tokyo Bay was constructed to investigate its hydrodynamic response to major typhoon parameters, such as the point of landfall, approach angle, ...forward speed, size, and intensity. The typhoon simulation was validated for Typhoon Lan in 2017, and 31 hypothetical storm surge scenarios were generated to establish the sensitivity of peak surge height to the variation in typhoon parameters. The maximum storm surge height in the upper bay adjacent to the Tokyo Metropolitan Area was found to be highly sensitive to the forward speed and size of the passing typhoon. However, the importance of these parameters in disaster risk reduction has been largely overlooked by researchers and disaster managers. It was also determined that of the many hypothetical typhoon tracks evaluated, the slow passage of a large and intense typhoon transiting parallel to the longitudinal axis of Tokyo Bay, making landfall 25 km southwest, is most likely to cause a hazardous storm surge scenario in the upper-bay area. The results of this study are expected to be useful to disaster managers for advanced preparation against destructive storm surges.
Antagonistic microorganisms against Rhizoctonia solani were isolated and their antifungal activities were investigated. Two hundred sixteen bacterial isolates were isolated from various soil samples ...and 19 isolates were found to antagonize the selected plant pathogenic fungi with varying degrees. Among them, isolate C9 was selected as an antagonistic microorganism with potential for use in further studies. Treatment with the selected isolate C9 resulted in significantly reduced incidence of stem-segment colonization by R. solani AG2-2(Ⅳ) in Zoysia grass and enhanced growth of grass. Through its biochemical, physiological, and 16S rDNA characteristics, the selected bacterium was identified as Bacillus subtilis subsp. subtilis. Mannitol (1%) and soytone (1%) were found to be the best carbon and nitrogen sources, respectively, for use in antibiotic production. An antibiotic compound, designated as DG4, was separated and purified from ethyl acetate extract of the culture broth of isolate C9. On the basis of spectral data, including proton nuclear magneric resonance (¹H NMR), carbon nuclear magneric resonance (∨13C NMR), and mass analyses, its chemical structure was established as a stereoisomer of acetylbutanediol. Application of the ethyl acetate extract of isolate C9 to several plant pathogens resulted in dose-dependent inhibition. Treatment with the purified compound (an isomer of acetylbuanediol) resulted in significantly inhibited growth of tested pathogens. The cell free culture supernatant of isolate C9 showed a chitinase effect on chitin medium. Results from the present study demonstrated the significant potential of the purified compound from isolate C9 for use as a biocontrol agent as well as a plant growth promoter with the ability to trigger induced systemic resistance of plants.
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