Earthquake ground motion amplification for surface waves

Surface waves from earthquakes are known to cause strong damage, especially for larger structures such as skyscrapers and bridges. However, common practice in characterizing seismic hazard at a specific site considers the effect of near-surface geology on only vertically propagating body waves. Here we show that surface waves have a unique and different frequency-dependent response to known geologic structure and that this amplification can be analytically calculated in a manner similar to current hazard practices. Applying this framework to amplification in the Los Angeles Basin, we find that peak ground accelerations for certain large regional earthquakes are underpredicted if surface waves are not properly accounted for and that the frequency of strongest ground motion amplification can be significantly different. Including surface-wave amplification in hazards calculations is therefore essential for accurate predictions of strong ground motion for future San Andreas Fault ruptures

Explaining Extreme Ground Motion in Osaka Basin during the 2011 Tohoku Earthquake

Despite being 770 km away from the epicenter, observed ground motions due to the Tohoku earthquake in the Osaka Basin were unexpectedly large, with an amplification of more than a factor of 20 compared to immediately outside the basin, and including 2.7 m peak-to-peak roof displacements at one high-rise building. The local ground motions exceeded expectations based on standard computations of site response by a factor of 3, predicted frequencies of peak acceleration were off by at least 50%, and such discrepancies have not yet been explained quantitatively. Here we show that utilizing semianalytic theory for surface-wave amplification, we are able to accurately predict both the amplitudes and frequencies of large ground amplification in the Osaka Basin using only knowledge of the local one-dimensional structure. Comparison between this simple prediction and observed amplification was not expected to be so favorable and suggests that simple one-dimensional surface-wave site amplification factors can be useful in the absence of full three-dimensional wave propagation simulations. Such surface-wave amplification factors can be included in addition to the standard measures of site-specific site amplification and should help explain strong ground motion variability in future large earthquakes that shake Osaka Basin and elsewhere in the world

Dual disadvantage and dispersion dynamics for income distributions

Income distribution has been a longstanding focus of social and economic interest, but never more so than in recent times. New metrics for disadvantage and spread enable a more precise differentiation of directional asymmetry and dispersion, drawing on an internal contextual perspective. The dual metrics for asymmetry and spread can be plotted over time into a phase plane, enabling comparative social welfare perspectives over time and between countries. The methods are utilised to study the dramatic changes that took place in Europe prior to and after the GFC. Major differences are revealed. In terms of asymmetry and spread, some countries have been fallers (lower in both) while other countries are risers

Asymmetry and performance metrics for equity returns

An assumption of symmetric asset returns, together with globally risk averse utility functions, is unappealing for fund managers and other activist investors, whose preferences switch between risk aversion on the downside and risk seeking on the upside. A performance return criterion is originated that is more consistent with the implicit Friedman-Savage utility ordering. Adapted from recent developments in the income distribution literature, the proposed metric weights the lower versus upper conditional expected returns, while a dual spread or dispersion metric also exists. The resulting performance metric is easy to compute. A point of departure is the conventional Sharpe performance ratio, with the empirical comparisons extending to a range of existing performance criteria. In contrast, the proposed W-metric results in different and more embracing performance rankings

Amplification and Attenuation across USArray using Ambient Noise Wavefront Tracking

As seismic traveltime tomography continues to be refined using data from the vast USArray data set, it is advantageous to also exploit the amplitude information carried by seismic waves. We use ambient noise cross correlation to make observations of surface wave amplification and attenuation at shorter periods (8–32 s) than can be observed with only traditional teleseismic earthquake sources. We show that the wavefront tracking approach can be successfully applied to ambient noise correlations, yielding results quite similar to those from earthquake observations at periods of overlap. This consistency indicates that the wavefront tracking approach is viable for use with ambient noise correlations, despite concerns of the inhomogeneous and unknown distribution of noise sources. The resulting amplification and attenuation maps correlate well with known tectonic and crustal structure; at the shortest periods, our amplification and attenuation maps correlate well with surface geology and known sedimentary basins, while our longest period amplitudes are controlled by crustal thickness and begin to probe upper mantle materials. These amplification and attenuation observations are sensitive to crustal materials in different ways than traveltime observations and may be used to better constrain temperature or density variations. We also value them as an independent means of describing the lateral variability of observed Rayleigh wave amplitudes without the need for 3-D tomographic inversions

The Propagation and Amplification of Surface Waves

The observation of surface waves from cross-correlations of ambient noise has proven to be an invaluable tool for the recovery of seismic travel times. Such techniques allow the construction of 3D velocity models and subsequent geologic interpretations in regions where tomography would otherwise be difficult due to the paucity of seismicity and short seismic array deployment times. One such model is developed here for offshore southern California using an array of Ocean Bottom Seismometers to better understand the tectonic history of the region. However, for accurate hazard evaluation, characterizations of the spatial variability of ground motion amplitudes are also desired. Unfortunately, the amplitudes from noise cross-correlations are systematically biased by the spatial-, frequency- and temporal variability of noise sources. We demonstrate in this thesis that an ambient-noise based wavefront tracking technique using an array of stations can recover site-amplification and attenuation estimates successfully and robustly. This is applied on two different scales: to a very dense array of more than 5,000 geophones in the city of Long Beach, CA, and in a broader, continental scale to instruments from the USArray. Finally, we discuss the propagation of surface waves in relation to seismic hazard and site characterization. We point out that the amplitude response and peak frequency of ground motion will be different for a given site, depending on the type of wave being considered. This work should be considered by any future seismic hazard evaluation where surface waves may cause damage.</p

Fraud and Abuse Panel

A panel discussion on some concerns that we have about value based reimbursement structures. The panel today consists of two private practice attorneys and one government attorney. We have litigators and regulatory attorneys, so a good mix of attorneys across the spectrum

The 2017 Vermont Opioid Prescribing Rules: Prescriber Attitudes

Introduction. In July of 2017, Vermont enacted new rules on acute opioid pre- scribing to reduce misuse, addiction, and overdose associated with prescription opioids. The new rules include requirements of non-opioid therapy use when possible, querying VPMS, patient education and informed consent, and co-prescription of naloxone. Our study objective was to gain insight into the perspectives of opioid prescribers on the new rules. Methods. The 17-item survey included closed and open-ended questions addressing prescriber perceptions about the new rules as well as demographic information about respondents. The survey was sent to Vermont-based opioid prescribers via email, to multiple healthcare organizations and professional societies, and through personal contacts. Open-ended responses were categorized using paired reviewers and group consensus, using a grounded theory approach. Results. A total of 431 responses were obtained, with MD/DOs accounting for 65%, APRNs- 14%, DDS/DMD- 7%, PAs-13%, and NDs- 1%. Of the respondents, 75% thought that more restrictive opioid prescribing rules were necessary, 74% felt the new rules would have some positive effect on the opioid crisis, but only 48% were in favor of the new rules. Barriers to implementation included co-prescribing naloxone (50% were unsuccessful), justifying exceptions to rules in medical record (46% unsuc- cessful), considering non-pharmacologic therapies (39% unsuccessful), and adhering to prescription limits (31% unsuccessful). Conclusions. Roll-out of the new rules has been criticized for implementation issues, overall reducing favorability among prescribers. Feedback obtained may be utilized by the Vermont Health Department and by other states to improve current models of opioid prescribing.https://scholarworks.uvm.edu/comphp_gallery/1264/thumbnail.jp

SAG/ROC2 E3 ligase regulates skin carcinogenesis by stage-dependent targeting of c-Jun/AP1 and IκB-α/NF-κB

Sensitive to apoptosis gene (SAG)/regulator of cullins-2–Skp1-cullin–F-box protein (SCF) E3 ubiquitin ligase regulates cellular functions through ubiquitination and degradation of protein substrates. We report that, when expressed in mouse epidermis driven by the K14 promoter, SAG inhibited TPA-induced c-Jun levels and activator protein-1 (AP-1) activity in both in vitro primary culture, in vivo transgenic mice, and an AP-1– luciferase reporter mouse model. After AP-1 inactivation, epidermal proliferation induced by 7,12-dimethylbenz(a)-anthracene/12-O-tetradecanoylphorbol-13-acetate at the early stage of carcinogenesis was substantially inhibited. Later stage tumor formation was also substantially inhibited with prolonged latency and reduced frequency of tumor formation. Interestingly, SAG expression increased tumor size, not because of accelerated proliferation, but caused by reduced apoptosis resulting, at least in part, from nuclear factor κB (NF-κB) activation. Thus, SAG, in a manner depending on the availability of F-box proteins, demonstrated early-stage suppression of tumor formation by promoting c-Jun degradation, thereby inhibiting AP-1, and later-stage enhancement of tumor growth, by promoting inhibitor of κBα degradation to activate NF-κB and inhibit apoptosis

Whole-genome sequencing shows that patient-to-patient transmission rarely accounts for acquisition of Staphylococcus aureus in an intensive care unit

BACKGROUND  Strategies to prevent Staphylococcus aureus infection in hospitals focus on patient-to-patient transmission. We used whole-genome sequencing to investigate the role of colonized patients as the source of new S. aureus acquisitions, and the reliability of identifying patient-to-patient transmission using the conventional approach of spa typing and overlapping patient stay. METHODS Over 14 months, all unselected patients admitted to an adult intensive care unit (ICU) were serially screened for S. aureus. All available isolates (n = 275) were spa typed and underwent whole-genome sequencing to investigate their relatedness at high resolution. RESULTS Staphylococcus aureus was carried by 185 of 1109 patients sampled within 24 hours of ICU admission (16.7%); 59 (5.3%) patients carried methicillin-resistant S. aureus (MRSA). Forty-four S. aureus (22 MRSA) acquisitions while on ICU were detected. Isolates were available for genetic analysis from 37 acquisitions. Whole-genome sequencing indicated that 7 of these 37 (18.9%) were transmissions from other colonized patients. Conventional methods (spa typing combined with overlapping patient stay) falsely identified 3 patient-to-patient transmissions (all MRSA) and failed to detect 2 acquisitions and 4 transmissions (2 MRSA). CONCLUSIONS Only a minority of S. aureus acquisitions can be explained by patient-to-patient transmission. Whole-genome sequencing provides the resolution to disprove transmission events indicated by conventional methods and also to reveal otherwise unsuspected transmission events. Whole-genome sequencing should replace conventional methods for detection of nosocomial S. aureus transmission