Using HEM surveys to evaluate disposal of by-product water from CBNG development in the Powder River Basin, Wyoming

Production of methane from thick, extensive coal beds in the Powder River Basin of Wyoming has created water management issues. Since development began in 1997, more than 650 billion liters of water have been produced from approximately 22,000 wells. Infiltration impoundments are used widely to dispose of by-product water from coal bed natural gas (CBNG) production, but their hydrogeologic effects are poorly understood. Helicopter electromagnetic surveys (HEM) were completed in July 2003 and July 2004 to characterize the hydrogeology of an alluvial aquifer along the Powder River. The aquifer is receiving CBNG produced water discharge from infiltration impoundments. HEM data were subjected to Occam's inversion algorithms to determine the aquifer bulk conductivity, which was then correlated towater salinity using site-specific sampling results. The HEM data provided high-resolution images of salinity levels in the aquifer, a result not attainable using traditional sampling methods. Interpretation of these images reveals clearly the produced water influence on aquifer water quality. Potential shortfalls to this method occur where there is no significant contrast in aquifer salinity and infiltrating produced water salinity and where there might be significant changes in aquifer lithology. Despite these limitations, airborne geophysical methods can provide a broadscale (watershed-scale) tool to evaluate CBNG water disposal, especially in areas where field-based investigations are logistically prohibitive. This research has implications for design and location strategies of future CBNG water surface disposal facilities within the Powder River Basin. © 2008 2008 Society of ExplorationGeophysicists. All rights reserved

The American Association for the Surgery of Trauma Severity Grade is valid and generalizable in adhesive small bowel obstruction

BACKGROUND The American Association for the Surgery of Trauma (AAST) anatomic severity grading system for adhesive small bowel obstruction (ASBO) was validated at a single institution. We aimed to externally validate the AAST ASBO grading system using the Eastern Association for the Surgery of Trauma multi-institutional small bowel obstruction prospective observational study. METHODS Adults (age 18) with (ASBO) were included. Baseline demographics, physiologic parameters (heart rate, blood pressure, respiratory rate), laboratory tests (lactate, hemoglobin, creatinine, leukocytosis), imaging findings, operative details, length of stay, and Clavien-Dindo complications were collected. The AAST ASBO grades were assigned by two independent reviewers based on imaging findings. Kappa statistic, univariate, and multivariable analyses were performed. RESULTS There were 635 patients with a mean (SD) age of 61 17.8 years, 51% female, and mean body mass index was 27.5 +/- 8.1. The AAST ASBO grades were: grade I (n = 386, 60.5%), grade II (n = 135, 21.2%), grade III (n = 59, 9.2%), grade IV (n = 55, 8.6%). Initial management included: nonoperative (n = 385; 61%), laparotomy (n = 200, 31.3%), laparoscopy (n = 13, 2.0%), and laparoscopy converted to laparotomy (n = 37, 5.8%). An increased median [IQR] AAST ASBO grade was associated with need for conversion to an open procedure (2 [1-3] vs. 3 [2-4], p = 0.008), small bowel resection (2 [2-2] vs. 3 [2-4], p < 0.0001), postoperative temporary abdominal closure (2 [2-3] vs. 3 [3-4], p < 0.0001), and stoma creation (2 [2-3] vs. 3 [2-4], p < 0.0001). Increasing AAST grade was associated with increased anatomic severity noted on imaging findings, longer duration of stay, need for intensive care, increased rate of complication, and higher Clavien-Dindo complication grade. CONCLUSION The AAST ASBO severity grading system has predictive validity for important clinical outcomes and allows for standardization across institutions, providers, and future research focused on optimizing preoperative diagnosis and management algorithms. LEVEL OF EVIDENCE Prognostic, level III

In situ seismic measurements in borehole LB-08A in the Bosumtwi impact structure, Ghana: Preliminary interpretation

In order to assist in the interpretation of previous seismic refraction and reflection surveys, a vertical seismic profile was acquired in the Lake Bosumtwi (Ghana) hard-rock core hole LB-08A. No seismic reflections are seen in the up-going wave field obtained, and this observation is consistent with the lack of reflectivity observed in the corresponding 2-D surface seismic profile obtained in earlier studies. Direct down-going P-waves were found both in the cased sediment column from a depth of 73 m to 239 m below the lake surface and in the open-hole hard rock section from a depth of 239 m to 451 m of LB-08A. Analysis of the observed travel times indicates a nearly constant P-wave velocity of 1520 m/s through the soft lacustrine sediments. In the hard-rock, however, the P-wave velocity rapidly increases by nearly 30% from 2600 m/s to 3340 m/s. These values are in good agreement with the gross velocity structure obtained in the earlier joint inversion of seismic reflection and refraction data. These values are low relative to those expected for the metasedimentary protoliths, an observation that has been made at other young impact structures of similar size. The low velocities, together with the fact that they increase so rapidly, is suggestive of a decreasing density of fractures and microcracks with depth. Consequently, the seismic velocity trend may provide a proxy measure of damage, and hence, the decay of the shock pressure from the impact point. Validation of this requires additional detailed studies of the porosity structure in the core.The Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

Cross-modal prediction in speech depends on prior linguistic experience

The sight of a speaker’s facial movements during the perception of a spoken message can benefit speech processing through online predictive mechanisms. Recent evidence suggests that these predictive mechanisms can operate across sensory modalities, that is, vision and audition. However, to date, behavioral and electrophysiological demonstrations of cross-modal prediction in speech have considered only the speaker’s native language. Here, we address a question of current debate, namely whether the level of representation involved in cross-modal prediction is phonological or pre-phonological. We do this by testing participants in an unfamiliar language. If cross-modal prediction is predominantly based on phonological representations tuned to the phonemic categories of the native language of the listener, then it should be more effective in the listener’s native language than in an unfamiliar one. We tested Spanish and English native speakers in an audiovisual matching paradigm that allowed us to evaluate visual-to-auditory prediction, using sentences in the participant’s native language and in an unfamiliar language. The benefits of cross-modal prediction were only seen in the native language, regardless of the particular language or participant’s linguistic background. This pattern of results implies that cross-modal visual-to-auditory prediction during speech processing makes strong use of phonological representations, rather than low-level spatiotemporal correlations across facial movements and sounds