PubMed Health⌕ Search

Biomedical subjects

John Marler

Publications and source records attributed to John Marler.

4 recordsLinked to original sources
PubMed2005

NIHSS training and certification using a new digital video disk is reliable.

BACKGROUND AND PURPOSE: NIH Stroke Scale certification is required for participation in modern stroke clinical trials and as part of good clinical care in stroke centers. The existing training and certification videotapes, however, are more than 10 years old and do not contain an adequate balance of patient findings. METHODS: After producing a new NIHSS training and demonstration DVD, we selected 18 patients representing all possible scores on 15 scale items for a new certification DVD. Patients were divided into 3 certification groups of 6 patients each, balanced for lesion side, distribution of scale item findings, and total score. We sought to measure interrater reliability of the certification DVD using methodology previously published for the original videotapes. Raters were recruited from 3 experienced stroke centers. Each rater watched the new training DVD and then evaluated one of the 3 certification groups. RESULTS: Responses were received from 112 raters: 26.2% of all responses came from stroke nurses, 34.1% from emergency departments/other physicians, and 39.6% from neurologists. One half (50%) of raters were previously NIHSS-certified. Item responses were tabulated, scoring performed as previously published, and agreement measured with unweighted kappa coefficients for individual items and an intraclass correlation coefficient for the overall score. kappa ranged from 0.21+/-0.05 (ataxia) to 0.92+/-0.09 (LOC-C questions). Of 15 items, 2 showed poor, 11 moderate, and 2 excellent agreement based on kappa scores. The intraclass correlation coefficient for total score was 0.94 (95% confidence interval, 0.84 to 1.00). Reliability scores were similar among specialists and centers, and there were no differences between nurses and physicians. kappa scores trended higher among raters previously certified. CONCLUSIONS: These certification DVDs are reliable for NIHSS certification, and scoring sheets have been posted on a web site for real-time, online certification.

Cerebrovascular Disorders↗
PubMedDate not supplied

The permeability of the Elkhorn fault zone, South Park, Colorado.

The purposes of this study are to use both field and modeling approaches to characterize the permeability of a fault and to assess the role of the fault on regional ground water flow. The study subject is the Elkhorn fault, a low-angle reverse fault that brings Precambrian crystalline rocks over the sediments of Colorado's South Park Basin. The fault is hypothesized to act as a low-permeability barrier to flow, restricting interaction between the crystalline aquifer and the basin sediments. To test this hypothesis and to better predict the permeability structure of the fault, we synthesized geologic data to create a geologic model of the fault, conducted aquifer tests to estimate the hydrogeologic properties of the fault zone, and used ground water modeling to test the influence of a range of hydraulic properties for the fault zone on ground water flow in the region. Our study suggests that the fault is a low-permeability feature. Estimated heads are best matched to observations by modeling the fault as a 10-foot-thick interval of low-permeability fault gouge. Steady-state flow models show that much of the flow in the study area is topographically driven near land surface. Flow rates decrease with depth in the aquifers. In the footwall, ground water moves updip in the Michigan-San Isabel syncline to discharge in the South Park Basin. In the hanging wall, ground water moves east to a regional ground water divide. Sensitivity analyses indicate that hydraulic heads are most sensitive to changes in hydraulic conductivity and recharge.

Colorado↗