Quaternary rupture of a crustal fault beneath Victoria, British Columbia, Canada

The seismic potential of crustal faults within the forearc of the northern Cascadia subduction zone in British Columbia has remained elusive, despite the recognition of recent seismic activity on nearby fault systems within the Juan de Fuca Strait. In this paper, we present the first evidence for earthquake surface ruptures along the Leech River fault, a prominent crustal fault near Victoria, British Columbia. We use LiDAR and field data to identify >60 steeply dipping, semi-continuous linear scarps, sags, and swales that cut across both bedrock and Quaternary deposits along the Leech River fault. These features are part of an ~1-km-wide and up to >60-km-long steeply dipping fault zone that accommodates active forearc transpression together with structures in the Juan de Fuca Strait and the U.S. mainland. Reconstruction of fault slip across a deformed <15 ka colluvial surface near the center of the fault zone indicates ~6 m of vertical separation across the surface and ~4 m of vertical separation of channels incising the surface. These displacement data indicate that the Leech River fault has experienced at least two surface-rupturing earthquakes since the deglaciation following the last glacial maximum ca. 15 ka, and should therefore be incorporated as a distinct shallow seismic source in seismic hazard assessments for the region.This research was supported by an NSERC Discovery grant to KM and NSF EAR IRFP Grant #1349586 to CR

Camelot… a Quest or a Kingdom?

published or submitted for publicatio

Short- and intermediate-term survival after extracorporeal membrane oxygenation in children with cardiac disease

ObjectivesIn children with cardiac disease, common indications for extracorporeal membrane oxygenation (ECMO) include refractory cardiopulmonary resuscitation (E-CPR), failure to separate from cardiopulmonary bypass (OR-ECMO), and low cardiac output syndrome (LCOS-ECMO). Despite established acceptance, ECMO outcomes are suboptimal with a survival between 38% and 55%. We evaluated factors associated with significantly increased survival in cardiac patients requiring ECMO.MethodsWe conducted a retrospective investigation of consecutive patients undergoing ECMO between 2006 and 2010. Demographic, pre-ECMO, ECMO, and post-ECMO parameters were analyzed. Neurologic outcomes were assessed with the pediatric overall performance category scale at the latest follow-up.ResultsThere were 3524 admissions, 95 (3%) of which necessitated ECMO; 40 (42%) E-CPR, 31 (33%) OR-ECMO, and 24 (25%) LCOS-ECMO. The overall hospital survival was 73%. The within-groups hospital survival was 75% in E-CPR, 77% OR-ECMO and 62% LCOS-ECMO. In the multivariable logistic regression analysis, chromosomal anomalies (odds ratio [OR], 8; 95% confidence interval [CI], 2-35), single ventricle (OR ,6; 95% CI, 3-33), multiple ECMO runs (OR, 15; 95% CI, 4-42), higher 24-hour ECMO flows (OR, 8; 95% CI, 4-22), decreased lung compliance (OR, 5; 95% CI, 2-16), and need for plasma exchange (OR, 5; 95% CI, 3-18) were all significant factors associated with mortality. From the univariate analysis, a common parameter associated with mortality within all groups was intracranial hemorrhage. At 1.9 years (0.9, 2.9) of follow-up, 66% were still alive, and 89% of survivors had normal function or only mild neurodevelopmental disability.ConclusionsECMO was successfully used in children with cardiac disease with 73% and 66% short- and intermediate-term survival, respectively. The majority of the survivors had normal function or only a minimal neurodevelopmental deficit

Study on the optical and electrical properties of tetracyanoethylene doped bilayer graphene stack for transparent conducting electrodes

We report the optical and electrical properties of chemically-doped bilayer graphene stack by tetracyanoethylene, a strong electron acceptor. The Tetracyanoethylene doping on the bilayer graphene via charge transfer was confirmed by Raman spectroscopy and Infrared Fourier transform spectroscopy. Doped graphene shows a significant increase in the sheet carrier concentration of up to 1.520 × 1013 cm−2 with a concomitant reduction of the sheet resistance down to 414.1 Ω/sq. The high optical transmittance (ca. 84%) in the visible region in combination with the low sheet resistance of the Tetracyanoethylene-doped bilayer graphene stack opens up the possibility of making transparent conducting electrodes for practical applications

The Gas Transfer through Polar Sea Ice Experiment: Insights into the Rates and Pathways that Determine Geochemical Fluxes

Sea ice is a defining feature of the polar marine environment. It is a critical domain for marine biota and it regulates ocean-atmosphere exchange, including the exchange of greenhouse gases such as CO2 and CH4. In this study, we determined the rates and pathways that govern gas transport through a mixed sea ice cover. N2O, SF6, 3He, 4He, and Ne were used as gas tracers of the exchange processes that take place at the ice-water and air-water interfaces in a laboratory sea ice experiment. Observation of the changes in gas concentrations during freezing revealed that He is indeed more soluble in ice than in water; Ne is less soluble in ice, and the larger gases (N2O and SF6) are mostly excluded during the freezing process. Model estimates of gas diffusion through ice were calibrated using measurements of bulk gas content in ice cores, yielding gas transfer velocity through ice (kice) of ∼5 × 10−4 m d−1. In comparison, the effective air-sea gas transfer velocities (keff) ranged up to 0.33 m d−1 providing further evidence that very little mixed-layer ventilation takes place via gas diffusion through columnar sea ice. However, this ventilation is distinct from air-ice gas fluxes driven by sea ice biogeochemistry. The magnitude of keff showed a clear increasing trend with wind speed and current velocity beneath the ice, as well as the combination of the two. This result indicates that gas transfer cannot be uniquely predicted by wind speed alone in the presence of sea ice

Rapid axonal transport in focally demyelinated sciatic nerve

Focal demyelination was produced in rat sciatic nerve by unilateral intraneural injection of anti-galactocerebroside serum. A functional lesion was confirmed by the presence of nerve conduction block. Histologically, this corresponded to demyelination of 50-70% of the fibers in nerve cross sections; axonal structures appeared intact. At the time of maximal demyelination (7 d), 35S-methionine or 3H-fucose was injected bilaterally into the spinal cord ventral horn. At later times (5 hr-7 d), the sciatic nerve was removed and radioactivity in successive nerve segments was quantitated. The transport rates (approximately 260 mm/d) and the composition of transported proteins and glycoproteins (separated on 7-15% polyacrylamide gradient gels) were not altered in lesioned nerves relative to contralateral control nerves. Light microscopic autoradiographic analysis revealed a similar localization of axonally transported and deposited glycoproteins in demyelinated and control fibers. Initially (8 hr), the majority of label was over axons. Labeled glycoproteins remaining in the nerve after 1 week were retained mainly in axolemmal regions. We conclude that acute focal primary demyelination does not lead to major alterations in the transport or deposition of newly synthesized macromolecules