Seismic source functions and attenuation from local and teleseismic observations of the NTS events Jorum and Handley

Several strong-motion seismograms recorded at 8 km from a large nuclear test at Pahute Mesa, Nevada Test Site, are modeled using the Cagniard-de Hoop technique. The ratio of vertical to radial motions suggest that the peak values are produced by ray paths that penetrated to a depth several kilometers below the source. A homogeneous layered Earth model with velocity increasing with depth was used in the modeling of the velocity time histories. The upper portion of the velocity model was determined by averaging bore-hole data and the lower portion was obtained from regional refraction measurements. Assuming a modified Haskell (1967) source representation, ψ(t) = ψ_o[1 - e^(-Kt)(1 + Kt (Kt)^2/2 - B(Kt)^3)] we obtain a range of source descriptions with ψ_o varying with K and B, ψ_o (K,B). The range of source models for Jorum are ψ_o (5, 1) = 3.1, ψ_o (5, 2) = 1.7, and ψ_o (5, 3) = 1.2 times 10^(11) cm^3, respectively. Given an explosion source description, it is a straightforward task to determine the teleseismic attenuation from WWSSN observations. From both the short- and long-period observations from these events, an average t^* of 1.3 is obtained for compressional waves of a dominant 1-sec period. This estimate is insensitive to the range of K and B obtained from the near-field modeling

Tectonic implications of the Brawley earthquake swarm, Imperial Valley, California, January 1975

The Brawley earthquake swarm provided a unique opportunity for studying a highly interesting tectonic region. The swarm was most intense for a period of 4 days including 75 events with M_L between 3.0 and 4.7 with a spatial extent of 12 km. Precise relative hypocenters were obtained for 264 earthquakes (M_L ≧ 1.5) using a master event method to calibrate the USGS Imperial Valley array. These locations together with well-constrained focal mechanisms for 16 of the largest events suggest faulting on at least three distinct structures. Hypocentral depths ranged from 4 to 8 km, compared to a basement depth of about 6 km for this part of the Imperial Valley. The swarm began on a nearly vertical right-lateral fault striking N8°W (Brawley fault) about 8 km southeast of Brawley at a point which had experienced enhanced shallow seismicity during the preceding 4 days. The seismicity migrated bilaterally north and south from this point at a constant velocity of 0.5 km/hr terminating to the north on a steeply south dipping, N50°E-striking fault. This structure is on trend with splays associated with the northern end of ground breakage of the 1940 Imperial Valley earthquake. To the south the seismicity ended near the northern end of the 10 km of surface rupture mapped by R. V. Sharp, which continues on strike to a point near the Imperial fault. Tectonic interpretations include the transfer of right-lateral offset from the Imperial fault to the Brawley fault associated with the formation of a closed depression bounded on the west and east by these two faults

Simulation of strong ground motions

The estimation of potential strong ground motions at short epicentral distances (Δ = 10 to 25 km) resulting from large earthquakes, M ≧ 6.5, generally requires extrapolation of a limited data set. The goal of this project has been to quantify the extrapolation through a simulation technique that relies heavily upon the more extensive data set from smaller magnitude earthquakes. The simulation utilizes the smaller events as Green's functions for the elements of a larger fault. Comparison of the simulated peak acceleration and duration with the data from the Parkfield earthquake is very good. Simulation of three earthquakes, M = 5.5, 6.5, and 7.0 indicate that the slope of the peak acceleration versus distance curve (Δ = 5 to 25 km) flattens, for strike-slip earthquakes, as the magnitude increases

The effect of exercise on venous gas emboli and decompression sickness in human subjects at 4.3 psia

The contribution of upper body exercise to altitude decompression sickness while at 4.3 psia after 3.5 or 4.0 hours of 100% oxygen prebreathing at 14.7 psia was determined by comparing the incidence and patterns of venous gas emboli (VGE), and the incidence of Type 1 decompression sickness (DCS) in 43 exercising male subjects and 9 less active male Doppler Technicians (DT's). Each subject exercised for 4 minutes at each of 3 exercise stations while at 4.3 psia. An additional 4 minutes were spent monitoring for VGE by the DT while the subject was supine on an examination cot. In the combined 3.5 and 4.0 hour oxygen prebreathe data, 13 subjects complained of Type 1 DCS compared to 9 complaints from DT's. VGE were detected in 28 subjects compared to 14 detections from DT's. A chi-square analysis of proportions showed no statistically significantly difference in the incidence of Type 1 DCS or VGE between the two groups; however, the average time to detect VGE and to report Tyep 1 DCS symptoms were statistically different. It was concluded that 4 to 6 hours of upper body exercise at metabolic rates simulating EVA metabolic rates hastens the initial detection of VGE and the time to report Type 1 DCS symptoms as compared to DT's

Peak acceleration scaling studies

An acceleration time history can be decomposed into a series of operations that transfers energy from each point on the fault to the recording station ACC(t) = S * R * E * Q where S is the source time function, R represents rupture over a finite fault, E is the elastic propagation through the earth, and Q is the path attenuation, assumed to be linear. If these operators were exactly known, a deterministic approach to predicting strong ground motions would be straightforward. For the current study, E was computed from a velocity model that incorporates a stiff sedimentary layer over a southern California crust. A range of realistic rupture velocities have been obtained by other investigators and is incorporated into the simulation. Assumptions of the path averaged attenuation, Q, can be tested by comparing with observational data, as a function of distance, the parameters peak acceleration, and computed M_L. This provides a check on both the high frequency (∼ 5 Hz) and long-period (∼ 1 sec) behavior of E^* Q. An average curstal shear wave Q_β of 300 is found to be compatible with observational data (M_L = 4.5 to 5.0). Assumptions of S can be avoided by using real sources derived from accelerograms recorded at small epicentral distances (epicentral distance/source depth < 1). Using these operators, accelerograms have been simulated for strike-slip faulting for four magnitudes: 4.5; 5.5; 6.5; and 7.0. The shapes of the derived average peak ground acceleration (PGA) versus distance curves are well described by the simple equation PGA α [R + C(M)]^(−1.75), where R is the closest distance to the fault surface and C(4.5) = 6, C(5.5) = 12, C(6.5) = 22, and C(7.0) = 36 km

Potential use of oxygen as a metabolic biosensor in combination with T2*-weighted MRI to define the ischemic penumbra

We describe a novel magnetic resonance imaging technique for detecting metabolism indirectly through changes in oxyhemoglobin:deoxyhemoglobin ratios and T2* signal change during ‘oxygen challenge’ (OC, 5 mins 100% O2). During OC, T2* increase reflects O2 binding to deoxyhemoglobin, which is formed when metabolizing tissues take up oxygen. Here OC has been applied to identify tissue metabolism within the ischemic brain. Permanent middle cerebral artery occlusion was induced in rats. In series 1 scanning (n=5), diffusion-weighted imaging (DWI) was performed, followed by echo-planar T2* acquired during OC and perfusion-weighted imaging (PWI, arterial spin labeling). Oxygen challenge induced a T2* signal increase of 1.8%, 3.7%, and 0.24% in the contralateral cortex, ipsilateral cortex within the PWI/DWI mismatch zone, and ischemic core, respectively. T2* and apparent diffusion coefficient (ADC) map coregistration revealed that the T2* signal increase extended into the ADC lesion (3.4%). In series 2 (n=5), FLASH T2* and ADC maps coregistered with histology revealed a T2* signal increase of 4.9% in the histologically defined border zone (55% normal neuronal morphology, located within the ADC lesion boundary) compared with a 0.7% increase in the cortical ischemic core (92% neuronal ischemic cell change, core ADC lesion). Oxygen challenge has potential clinical utility and, by distinguishing metabolically active and inactive tissues within hypoperfused regions, could provide a more precise assessment of penumbra

Are General and Strategic Measures of Organizational Context and Leadership Associated with Knowledge and Attitudes toward Evidence-Based Practices in Public Behavioral Health Settings? A Cross-Sectional Observational Study

Background: Examining the role of modifiable barriers and facilitators is a necessary step toward developing effective implementation strategies. This study examines whether both general (organizational culture, organizational climate, and transformational leadership) and strategic (implementation climate and implementation leadership) organizational-level factors predict therapist-level determinants of implementation (knowledge of and attitudes toward evidence-based practices). Methods: Within the context of a system-wide effort to increase the use of evidence-based practices (EBPs) and recovery-oriented care, we conducted an observational, cross-sectional study of 19 child-serving agencies in the City of Philadelphia, including 23 sites, 130 therapists, 36 supervisors, and 22 executive administrators. Organizational variables included characteristics such as EBP initiative participation, program size, and proportion of independent contractor therapists; general factors such as organizational culture and climate (Organizational Social Context Measurement System) and transformational leadership (Multifactor Leadership Questionnaire); and strategic factors such as implementation climate (Implementation Climate Scale) and implementation leadership (Implementation Leadership Scale). Therapist-level variables included demographics, attitudes toward EBPs (Evidence-Based Practice Attitudes Scale), and knowledge of EBPs (Knowledge of Evidence-Based Services Questionnaire). We used linear mixed-effects regression models to estimate the associations between the predictor (organizational characteristics, general and strategic factors) and dependent (knowledge of and attitudes toward EBPs) variables. Results: Several variables were associated with therapists’ knowledge of EBPs. Clinicians in organizations with more proficient cultures or higher levels of transformational leadership (idealized influence) had greater knowledge of EBPs; conversely, clinicians in organizations with more resistant cultures, more functional organizational climates, and implementation climates characterized by higher levels of financial reward for EBPs had less knowledge of EBPs. A number of organizational factors were associated with the therapists’ attitudes toward EBPs. For example, more engaged organizational cultures, implementation climates characterized by higher levels of educational support, and more proactive implementation leadership were all associated with more positive attitudes toward EBPs. Conclusions: This study provides evidence for the importance of both general and strategic organizational determinants as predictors of knowledge of and attitudes toward EBPs. The findings highlight the need for longitudinal and mixed-methods studies that examine the influence of organizational factors on implementation

Non-Participants in Policy Efforts to Promote Evidence-Based Practices in a Large Behavioral Health System

Background: System-wide training initiatives to support and implement evidence-based practices (EBPs) in behavioral health systems have become increasingly widespread. Understanding more about organizations who do not participate in EBP training initiatives is a critical piece of the dissemination and implementation puzzle if we endeavor to increase access in community settings. Methods: We conducted 30 1-h semi-structured interviews with leaders in non-participating agencies who did not formally participate in system-wide training initiatives to implement EBPs in the City of Philadelphia, with the goal to understand why they did not participate. Results: We found that despite not participating in training initiatives, most agencies were adopting (and self-financing) some EBP implementation. Leadership from agencies that were implementing EBPs reported relying on previously trained staff to implement EBPs and acknowledged a lack of emphasis on fidelity. Most leaders at agencies not adopting EBPs did not have a clear understanding of what EBP is. Those familiar with EBPs in agencies not adopting EBPs reported philosophical objections to EBPs. When asked about quality assurance and treatment selection, leaders reported being guided by system audits. Conclusions: While it is highly encouraging that many agencies are adopting EBPs on their own, significant questions about fidelity and implementation success more broadly remain

Predictors of Community Therapists\u27 Use of Therapy Techniques in a Large Public Mental Health System

Importance Few studies have examined the effects of individual and organizational characteristics on the use of evidence-based practices in mental health care. Improved understanding of these factors could guide future implementation efforts to ensure effective adoption, implementation, and sustainment of evidence-based practices. Objective To estimate the relative contribution of individual and organizational factors on therapist self-reported use of cognitive-behavioral, family, and psychodynamic therapy techniques within the context of a large-scale effort to increase use of evidence-based practices in an urban public mental health system serving youth and families. Design, Setting, and Participants In this observational, cross-sectional study of 23 organizations, data were collected from March 1 through July 25, 2013. We used purposive sampling to recruit the 29 largest child-serving agencies, which together serve approximately 80% of youth receiving publically funded mental health care. The final sample included 19 agencies with 23 sites, 130 therapists, 36 supervisors, and 22 executive administrators. Main Outcomes and Measures Therapist self-reported use of cognitive-behavioral, family, and psychodynamic therapy techniques, as measured by the Therapist Procedures Checklist–Family Revised. Results Individual factors accounted for the following percentages of the overall variation: cognitive-behavioral therapy techniques, 16%; family therapy techniques, 7%; and psychodynamic therapy techniques, 20%. Organizational factors accounted for the following percentages of the overall variation: cognitive-behavioral therapy techniques, 23%; family therapy techniques, 19%; and psychodynamic therapy techniques, 7%. Older therapists and therapists with more open attitudes were more likely to endorse use of cognitive-behavioral therapy techniques, as were those in organizations that had spent fewer years participating in evidence-based practice initiatives, had more resistant cultures, and had more functional climates. Women were more likely to endorse use of family therapy techniques, as were those in organizations employing more fee-for-service staff and with more stressful climates. Therapists with more divergent attitudes and less knowledge about evidence-based practices were more likely to use psychodynamic therapy techniques. Conclusions and Relevance This study suggests that individual and organizational factors are important in explaining therapist behavior and use of evidence-based practices, but the relative importance varies by therapeutic technique

The Lantern Vol. 42, No. 1, Fall 1975

• The House • The Empty Man • Time • Corporea • Take Me • Elements of Nature • Hope • Acclimation • Road to Elat • Sinai • Jerusalem • Fatman • Ode to Grand Rapids • Ode to Cora • The Apple Cart • Next Time You\u27re Down South • Star Wreck • Eulogy to John Doe • A Postal Preoccupation • The Interview May Be Real (But Don\u27t Bet On It) • Winter Eve • My Love • God\u27s Children • A View From a Hill • Freedom For Us • Sleep Demonhttps://digitalcommons.ursinus.edu/lantern/1107/thumbnail.jp