Biomedical subjects

Ann Johnson

Publications and source records attributed to Ann Johnson.

22 records · Page 2Linked to original sources

PubMedDate not supplied

Characterization of infiltration rates from landfills: supporting groundwater modeling efforts.

The purpose of this paper is to review the literature to characterize infiltration rates from landfill liners to support groundwater modeling efforts. The focus of this investigation was on collecting studies that describe the performance of liners 'as installed' or 'as operated'. This document reviews the state of the science and practice on the infiltration rate through compacted clay liner (CCL) for 149 sites and geosynthetic clay liner (GCL) for 1 site. In addition, it reviews the leakage rate through geomembrane (GM) liners and composite liners for 259 sites. For compacted clay liners (CCL), there was limited information on infiltration rates (i.e., only 9 sites reported infiltration rates.), thus, it was difficult to develop a national distribution. The field hydraulic conductivities for natural clay liners range from 1 x 10(-9) cm s(-1) to 1 x 10(-4) cm s(-1), with an average of 6.5 x 10(-8) cm s(-1). There was limited information on geosynthetic clay liner. For composite lined and geomembrane systems, the leak detection system flow rates were utilized. The average monthly flow rate for composite liners ranged from 0-32 lphd for geomembrane and GCL systems to 0 to 1410 lphd for geomembrane and CCL systems. The increased infiltration for the geomembrane and CCL system may be attributed to consolidation water from the clay.

Fresh Water↗

PubMedDate not supplied

Public health education and practice using geographic information system technology.

The use of geographic information system (GIS) technology allows public health practitioners to explore disparities in health, analyze disease outbreaks, and prioritize the use of limited resources for improving population health. Nursing students benefit from use of World Wide Web GIS resources as they develop knowledge and skill in assessing population health and planning interventions. This article identifies the benefits of GIS for public health practitioners, presents a communicable disease control application of GIS, and discusses a GIS module used in an undergraduate nursing education course. Uniform standards for making health data available for public use with GIS are discussed.

Diffusion of Innovation↗

PubMedDate not supplied

Pre- and postoperative radiographic and computed tomographic evaluation of dogs with medial patellar luxation.

OBJECTIVE: To quantify, using radiographic and computed tomographic (CT) techniques, the effects of surgical procedures most commonly combined to treat dogs with medial patellar luxation (MPL). STUDY DESIGN: Prospective study. METHODS: Six dogs with 8 MPL were studied. Radiographs and CT of the pelvic limbs were obtained before and immediately after soft-tissue reconstruction, trochlear wedge recession, and tibial crest transposition. Radiographic measurements included angle of inclination, Norberg angle, quadriceps angle (QA), anteversion angle, ratio of the length of the patellar tendon (PT) to the length of the patella, and change in patella tendon angle. CT measurements included angle of inclination, Norberg angle, QA, anteversion angle, depth of the femoral trochlear groove, ratio of the middle femoral trochlear groove depth to the patella thickness, and tibial crest alignment. RESULTS: Conformation of the coxofemoral joint was not affected by surgery. Surgical treatment corrected the QA by 33-58%. Trochlear wedge recession was most effective in deepening the proximal trochlea by 103.5%. The ratio of the middle femoral trochlear groove depth to the thickness of the patella postoperatively resulted in 50% coverage of the patella. Tibial crest transposition resulted in caudalization of the PT by 8.5+/-3.0 degrees, with lateralization of the tibial tuberosity of 11.3 degrees. CONCLUSION: The effects of surgery for MPL can be quantified with radiographic and CT measurements. Surgical correction restored the alignment of the quadriceps and adequately deepened the femoral trochlear groove. Tibial crest transposition resulted in caudalization of the patella tendon and lateralization of the tibial tuberosity. CLINICAL RELEVANCE: These pilot data quantified the effects of surgical procedures most commonly combined to treat MPL. We hope to use these measurements to correlate surgical treatment with functional outcome and postoperative occurrence of luxation.

Animals↗

PubMedDate not supplied

The intertester and intratester reliability of hand volumetrics.

The purpose of this study was to examine the intertester and intratester reliability of hand volumetric measurements comparing two different protocols. The first protocol involved three clinicians at an outpatient facility interpreting the manufacturer's volumeter instructions. At the second university site, three testers utilized a modified version of the American Society of Hand Therapists' recommended protocol. Three measurements were taken of each of 30 nonedematous hands per site. Reliability was assessed using only the first measurement and using the mean of the three measurements. Results for both protocols revealed very high intertester reliability (ICC=0.99) whether using the first measurement or the mean of three measurements. Intratester reliability was also very high (ICC=0.99) using either protocol. Standard error of measurement values are included and additional variables, which may affect the reliability of hand volumetrics, are discussed. The authors conclude that there is high reliability with volumetric measurements.

Adult↗