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ABSTRACT: Numerical modeling of earthquake dynamics and derived insight for seismic hazard relies on credible, reproducible model results. The sequences of earthquakes and aseismic slip (SEAS) initiative has set out to facilitate community code comparisons, and verify and advance the next generation of physics-based earthquake models that reproduce all phases of the seismic cycle. With the goal of advancing SEAS models to robustly incorporate physical and geometrical complexities, here we present code comparison results from two new benchmark problems: BP1-FD considers full elastodynamic effects, and BP3-QD considers dipping fault geometries. Seven and eight modeling groups participated in BP1-FD and BP3-QD, respectively, allowing us to explore these physical ingredients across multiple codes and better understand associated numerical considerations. With new comparison metrics, we find that numerical resolution and computational domain size are critical parameters to obtain matching results. Codes for BP1-FD implement different criteria for switching between quasi-static and dynamic solvers, which require tuning to obtain matching results. In BP3-QD, proper remote boundary conditions consistent with specified rigid body translation are required to obtain matching surface displacements. With these numerical and mathematical issues resolved, we obtain excellent quantitative agreements among codes in earthquake interevent times, event moments, and coseismic slip, with reasonable agreements made in peak slip rates and rupture arrival time. We find that including full inertial effects generates events with larger slip rates and rupture speeds compared to the quasi-dynamic counterpart. For BP3-QD, both dip angle and sense of motion (thrust versus normal faulting) alter ground motion on the hanging and foot walls, and influence event patterns, with some sequences exhibiting similar-size characteristic earthquakes, and others exhibiting different-size events. These findings underscore the importance of considering full elastodynamics and nonvertical dip angles in SEAS models, as both influence short- and long-term earthquake behavior and are relevant to seismic hazard.

A community-based intervention study for suicide prevention was conducted in six towns (total population 43,964) in Akita Prefecture of Japan according to a quasi-experimental design to reduce suicide rates in rural towns. Public awareness raising activities using a health promotion approach emphasizing the empowerment of residents and civic participation were conducted. The welfare measures of promoting a sense of purpose among senior citizens and creating a community network were also taken. As a result, the suicide rate per 100,000 in the intervention towns decreased from 70.8 before intervention (1999) to 34.1 after intervention (2004). The suicide rate per 100,000 in the control towns was 47.8 before intervention and 49.1 after intervention.

This study revealed factors associated with reproductive health risk behavior among high school students in the Republic of the Marshall Islands. The survey was conducted among high school students from grades 9 through 12 at 2 schools in Majuro, the capital of the Marshall Islands. The questions asked inquired about knowledge, attitude, and behavior related to reproductive health, experience of sexual acts and pregnancy. Multiple logistic regression analysis was performed to assess the association between risk behavior and knowledge, attitude, and other factors. Data obtained from 433 students were used in the analysis. Factors significantly associated with reproductive health risk behavior among both the boys and the girls were a negative attitude toward condom use (odds ratio of the risk group to the low-risk group: boys, 19.54; girls 4.10), not considering receiving public health information and services as a human right (8.10, 3.96), and not knowing where to go for consultation about questions and concerns related to sex (3.32, 4.73). A factor associated with risk behavior in boys alone was acceptance of sexual acts without love (8.46), and factors in girls alone were insufficient knowledge concerning routes of infection by sexually transmitted diseases (6.75) and lack of future life plans (5.00). Neither age nor sex education was a significant predictor. In conclusion, considering reproductive health not to be a personal right was associated with the risk behavior of high school students in the Marshall Islands in regard to reproductive health.

Geophysical observations suggest that temporal changes in pore fluid pressure correlate with slow slip events (SSEs) at some subduction zones, including the Hikurangi and Cascadia subduction zones. These fluctuations in pore fluid pressure are attributed to fluid migration before and during SSEs, which may modulate SSE occurrence. To examine the effect of pore fluid pressure changes on SSE generation, we develop numerical models in which periodic pore‐pressure perturbations are applied to a stably sliding, rate‐strengthening fault. By varying the physical characteristics of the pore‐pressure perturbations (amplitude, characteristic length and period), we find models that reproduce shallow Hikurangi SSE properties (duration, magnitude, slip, recurrence) and SSE moments and durations from different subduction zones. The stress drops of modeled SSEs range from ∼20–120 kPa while the amplitudes of pore‐pressure perturbations are several MPa, broadly consistent with those inferred from observations. Our results indicate that large permeability values of ∼10−14 to 10−10 m2 are needed to reproduce the observed SSE properties. Such high values could be due to transient and localized increases in fault zone permeability in the shear zone where SSEs occur. Our results suggest that SSEs may arise on faults in rate‐strengthening frictional conditions subject to pore‐pressure perturbations. Plain Language Summary: Slow slip events (SSEs), with slower velocities and longer durations than regular earthquakes, have been detected at several subduction zones worldwide. Recent observations have led researchers to infer that pore fluid pressure—the pressure of fluids in the pore space of rocks—changes during SSEs that occur along the shallow (<15 km depth) portion of the Hikurangi subduction zone, where the Pacific Plate subducts beneath the Australian plate. Similar observations have been reported during SSEs in different subduction zones. However, how pore fluid pressure changes are linked to SSEs is poorly understood. To investigate this issue, we develop physics‐based models in which periodic perturbations in pore fluid pressure are imposed on a fault governed by the expected frictional behavior of rocks derived from laboratory experiments. These pore fluid pressure perturbations induce SSEs, and the features of these events (duration, magnitude, peak velocity, recurrence interval) change with the characteristics of the pore fluid pressure change (size, amplitude, and period). After exploring different perturbation characteristics, we find models that capture the observed features of SSEs along the Hikurangi margin and in different subduction zones. This study suggests that pore fluid pressure changes may play an important role in SSE occurrence. Key Points: Periodic pore fluid pressure perturbations on a rate‐strengthening fault induce slow slip events (SSEs)Source properties of induced SSEs vary with perturbation characteristics (length scale, amplitude, period)Model reproduces source properties of shallow Hikurangi SSEs, and duration and magnitude of SSEs in different subduction zones [ABSTRACT FROM AUTHOR]

Background: While women's parity status and education level have independent associations with cardiovascular and other diseases, no studies have evaluated the additive interaction of these two factors. Therefore, we examined the additive interaction between parity and education level on mortality from stroke, coronary heart disease, total cardiovascular disease, cancer, non-cardiovascular disease, and non-cancer causes, and all causes in Japanese women.Methods: This study followed 41,242 women aged 40-79 years without a history of cardiovascular disease or cancer from 1988 to 1990 until 2009. Baseline parity and education level were classified into four categories, with highly educated parous women as the reference group. Cox proportional hazards regression analyses were performed to calculate the risk of mortality. We also assessed the additive interactions between parity and education level on mortality from cardiovascular disease and other causes using the relative excess risk due to interaction obtained using Cox models.Results: During the median follow-up period of 19.1 years, we identified 6299 deaths. In a multivariable model adjusted for cardiovascular disease and other disease risk factors, nulliparous women with low education levels had increased multivariable-adjusted hazard ratios of 1.67 (95% confidence interval [CI] 1.13, 2.47) for stroke, 1.98 (95% CI 1.15, 3.39) for coronary heart disease, 1.71 (95% CI 1.34,2.18) for total cardiovascular disease, 1.69 (95% CI 1.33, 2.14) for non-cardiovascular and non-cancer, and 1.51 (95% CI 1.30, 1.75) for all-cause mortality when compared with highly educated parous women. Moreover, we observed significant additive interactions between parity and education level on total cardiovascular disease mortality (P = 0.04), non-cardiovascular disease and non-cancer mortality (P = 0.01), and all-cause mortality (P = 0.005).Conclusions: Nulliparity and low education levels are super-additively associated with total cardiovascular disease, non-cardiovascular and non-cancer, and all-cause mortality risks, suggesting that nulliparous women with low education levels need specific support for preventing mortality related to cardiovascular and other diseases. [ABSTRACT FROM AUTHOR]

We studied the correlations among sunspot numbers, business cycles, and suicide mortalitites. Based on data from Japan between 1971 and 2001, a significant negative correlation between sunspot numbers and unemployment rate was round, R = .17. The correlation between suicide mortality and unemployment rate was positive for males (R = .46) and negative for females (R = .69). Both are statistically significant. The hypothesis that variation of sun activity may affect the economy and the unemployment rate and hence increase the male suicide mortality is raised.