Geodetic Imaging of Coseismic Slip and Postseismic Afterslip: Sparsity Promoting Methods Applied to the Great Tohoku Earthquake

Geodetic observations of surface displacements during and following earthquakes such as the March 11, 2011 great Tohoku earthquake can be used to constrain the spatial extent of coseismic slip and postseismic afterslip, and characterize the spectrum of earthquake cycle behaviors. Slip models are often regularized by assuming that slip on the fault varies smoothly in space, which may result in the artificial smearing of fault slip beyond physical boundaries. Alternatively, it may be desirable to estimate a slip distribution that is spatially compact and varies sharply. Here we show that sparsity promoting state vector regularization methods can be used to recover slip distributions with sharp boundaries, representing an alternative end-member result to very smooth slip distributions. Using onshore GPS observations at 298 stations during and in the ∼2 weeks following the Tohoku earthquake, we estimate a band of coseismic slip between 30 and 50 km depth extending 500 km along strike with a maximum slip of 64 m, corresponding to a minimum magnitude estimate of $M_W = 8.8$. Our estimate of afterslip is located almost exclusively down-dip of the coseismic rupture, with a transition between 40 and 50 km depth and an equivalent moment magnitude $M_W = 8.2$. This depth may be interpreted as coincident with the transition from velocity strengthening to velocity weakening frictional behavior, consistent with the upper limit of cold subduction estimates of the thermal structure of the Japan trench.Earth and Planetary Science

Sexual behaviour of men and women within age-disparate partnerships in South Africa: implications for young women's HIV risk

BACKGROUND: Age-disparate partnerships are hypothesized to increase HIV-risk for young women. However, the evidence base remains mixed. Most studies have focused only on unprotected sex among women in the partnership. Consequently, little is known about other risky behaviours, such as transactional sex, alcohol use, and concurrency, as well as the behaviours of the men who partner with young women. We therefore examined differences in various sexual behaviours of both young women and their male partners by partnership age difference. METHODS: We used nationally representative data from South Africa (2012) on partnerships reported by 16-24 year old black African women (n = 818) and by black African men in partnerships with 16-24 year old women (n = 985). We compared sexual behaviours in age-disparate partnerships and age-similar partnerships, using multiple logistic regression to control for potential confounders and to assess rural/urban differences. RESULTS: Young women in age-disparate partnerships were more likely to report unprotected sex than young women in similar-aged partnerships (aOR:1.51; p = 0.014; 95%CI:1.09-2.11). Men in partnerships with young women were more likely to report unprotected sex (aOR:1.92; p<0.01; 95%CI:1.31-2.81), transactional sex (aOR:2.73; p<0.01; 95%CI:1.64-4.56), drinking alcohol before sex (aOR:1.60; p = 0.062; 95%CI:0.98-2.61), and concurrency (aOR:1.39; p = 0.097; 95%CI:0.94-2.07) when their partners were five or more years younger. The association between age-disparate partnerships and transactional sex (aOR:4.14; p<0.01; 95%CI: 2.03-8.46) and alcohol use (aOR:2.24; p<0.013; 95%CI:1.20-4.19) was only found in urban areas. CONCLUSIONS: Results provide evidence that young women's age-disparate partnerships involve greater sexual risk, particularly through the risky behaviours of their male partners, with the risk amplified for young women in urban areas

Geodetic Constraints on San Francisco Bay Area Fault Slip Rates and Potential Seismogenic Asperities on the Partially Creeping Hayward Fault

The Hayward fault in the San Francisco Bay Area (SFBA) is sometimes considered unusual among continental faults for exhibiting significant aseismic creep during the interseismic phase of the seismic cycle while also generating sufficient elastic strain to produce major earthquakes. Imaging the spatial variation in interseismic fault creep on the Hayward fault is complicated because of the interseismic strain accumulation associated with nearby faults in the SFBA, where the relative motion between the Pacific plate and the Sierra block is partitioned across closely spaced subparallel faults. To estimate spatially variable creep on the Hayward fault, we interpret geodetic observations with a three-dimensional kinematically consistent block model of the SFBA fault system. Resolution tests reveal that creep rate variations with a length scale of <15 km are poorly resolved below 7 km depth. In addition, creep at depth may be sensitive to assumptions about the kinematic consistency of fault slip rate models. Differential microplate motions result in a slip rate of 6.7 ± 0.8 mm/yr on the Hayward fault, and we image along-strike variations in slip deficit rate at ∼15 km length scales shallower than 7 km depth. Similar to previous studies, we identify a strongly coupled asperity with a slip deficit rate of up to 4 mm/yr on the central Hayward fault that is spatially correlated with the mapped surface trace of the 1868 $M_W = 6.9–7.0$ Hayward earthquake and adjacent to gabbroic fault surfaces.Earth and Planetary Science

Total Variation Regularization of Geodetically and Geologically Constrained Block Models for the Western United States

Geodetic observations of interseismic deformation in the Western United States provide con- straints on microplate rotations, earthquake cycle processes, and slip partitioning across the Pacific–North America Plate boundary. These measurements may be interpreted using block models, in which the upper crust is divided into microplates bounded by faults that accumulate strain in a first-order approximation of earthquake cycle processes. The number and geometry of microplates are typically defined with boundaries representing a limited subset of the large number of potentially seismogenic faults. An alternative approach is to include a large number of potentially active faults bounding a dense array of microplates, and then algorithmically estimate the boundaries at which strain is localized. This approach is possible through the application of a total variation regularization (TVR) optimization algorithm, which simultaneously minimizes the L2 norm of data residuals and the L1 norm of the variation in the differential block motions. Applied to 3-D spherical block models, the TVR algorithm can be used to reduce the total variation between estimated rotation vectors, effectively grouping microplates that rotate together as larger blocks, and localizing fault slip on the boundaries of these larger block clusters. Here we develop a block model comprised of 137 microplates derived from published fault maps, and apply the TVR algorithm to identify the kinematically most important faults in the western United States. This approach reveals that of the 137 microplates considered, only 30 unique blocks are required to approximate deformation in the western United States at a residual level of \u3c2 mm yr−1

Site Selection for Joint Logistics over the Shore (JLOTS) Operations Using Multi- Objective Decision Analysis

As the U.S. military faces an increasing need to deploy across a range of military operations and environments, the ability to establish and sustain logistics support remains a major challenge. The Engineer Research and Development Center is currently developing the Planning Logistics Analysis Network System (PLANS), a decision support tool, to facilitate strategic and operational logistics planning. This paper describes a site selection protocol for logistics operations occurring without a suitable port, commonly referred to as Logistics over-the Shore (LOTS) operations. The model uses multi- objective decision analysis techniques to weight different operational criteria to determine the best overall site for logistics over the shore operations. This tool will enhance the time and accuracy in determining an optimal site that meets the decision maker’s specific operational needs

Investigating the prevalence of reactive online searching in the COVID-19 pandemic

Background: The ongoing coronavirus disease (COVID-19) pandemic has placed an unprecedented strain on global society, healthcare, governments and mass media. Public dissemination of government policies, medical interventions and misinformation has been remarkably rapid and largely unregulated during the COVID-19 pandemic, resulting in increased misinterpretations, miscommunication, and public panic. Being the first full-scale global pandemic of the digital age, COVID-19 has presented novel challenges pertinent to government advice, the spread of news and misinformation, and the trade-off between the accessibility of science and the premature public use of unproven medical interventions. Objective: This study aims to assess the use of internet search terms relating to COVID-19 information and misinformation during the global pandemic, identify which were most used in six affected countries, investigate any temporal trends and the likely propagators of key search terms, and determine any correlation between the per capita cases and deaths with the adoption of these search terms in each of the six countries. Methods: This study uses relative search volume data extracted from Google Trends for search terms linked to the COVID-19 pandemic alongside per capita case and mortality data extracted from the European Open Data Portal, to identify the temporal dynamics of the spread of news and misinformation during the global pandemic in six affected countries (Australia, Germany, Italy, Spain, United Kingdom, United States of America). A correlation analysis was carried out to ascertain any correlation between the temporal trends of search term use and the rise of per capita mortality and disease cases. Results: Of the selected search terms, most were searched immediately following promotion by governments, public figures or viral circulation of unfounded claims, but also relating to the publication of scientific resources, which were sometimes misinterpreted before further dissemination. Strong correlations were identified between the volume of these COVID-19-related search terms, and per capita mortality and cases. Conclusions: These findings illustrate the increased rate and volume of public consumption of novel information during a global healthcare crisis. The strong positive correlation between mortality and online searching, particularly in countries with lower COVID-19 testing rates, may demonstrate the imperative to safeguard official communications and dispel misinformation in these countries. Online news, government briefings and social media provide a powerful tool for the dissemination of important information to the public during pandemics, but their misuse, and the presentation of misrepresented medical information, should be monitored, minimised and addressed to safeguard public safety. Ultimately, governments, public health authorities and scientists have a moral imperative to safeguard the truth and maintain an accessible discourse with the public to inhibit fear

Since The Start Of The Vaccines For Children Program, Uptake Has Increased, And Most Disparities Have Decreased

The Vaccines for Children program is a US government intervention aimed at increasing vaccination uptake by removing financial barriers that may prevent US children from accessing vaccinations. This study examined the impact that this intervention had on race and ethnicity–related and income-related disparities for diphtheria-tetanus-acellular pertussis, measles-mumps-rubella, and polio vaccinations, using data from the National Immunization Survey, 1995–2013. Vaccination rates increased across all races, ethnicities, and income groups following the introduction of the Vaccines for Children program. Disparities among race and ethnic groups narrowed considerably over time since the introduction of the vaccine program, although income-related disparities changed at different rates within racial and ethnic groups and in some cases increased. Government interventions aimed solely at reducing certain financial barriers to vaccination may fail to address other important aspects of cost or perceived benefits that influence vaccination uptake, especially among poorer children

Letter to the Editor concerning “A systematic review of controlled trials on visual stress using intuitive overlays or colorimeter"

yesWe read with interest the review written by Evans and Allen, and published in the Journal of Optometry, in July, 2016

Conducting empirical research with older people

We are investigating the role of online communities on the quality of life and wellbeing of people aged 65 years and over. We have conducted workshops and one-to- one semi-structured interviews, and have had free- flowing informal exchanges with our participants who have shared stories and incidents with us. In this paper, we discuss the challenges and opportunities of conducting empirical research with older people