Emergency medicine career change: associations with performances in medical school and in the first postgraduate year and with indebtedness

OBJECTIVE: Emergency medicine has been identified as the specialty that has gained the most young physicians who have changed their careers. To identify factors that may have contributed to such career changes, the authors compared the characteristics of three groups of physicians trained at their medical school: those who chose and stayed in emergency medicine, those who migrated into emergency medicine from other specialties, and those who moved out of emergency medicine. METHODS: A prospective longitudinal study was conducted. The sample consisted of physicians who chose emergency medicine as their careers at graduation and stayed in the specialty (n = 24), those who migrated from other specialties into emergency medicine (n = 51), and those who moved out of emergency medicine (n = 10). This sample was obtained from a total of 2,173 graduates of Jefferson Medical College between 1978 and 1987. The three groups of physicians were compared according to their academic performances both during medical school and after graduation. The dependent variables were freshmen and sophomore grade point averages (GPAs), written clinical examination scores, scores on National Board of Medical Examiners examination (Parts I, II, and III), and residency program directors' ratings. Age and indebtedness at medical school graduation and board certification status also were examined. RESULTS: Those physicians who stayed in emergency medicine and those who migrated from other specialties into emergency medicine had similar measures of academic performance, but both of these groups had higher academic performance measures and higher board certification rates than did the physicians who moved out of emergency medicine. Those who stayed in emergency medicine had the highest mean debt in the senior year of medical school. CONCLUSIONS: High academic performance and high indebtedness are factors associated with choosing or staying in the specialty of emergency medicine.     

Geophysical Investigation of the Sulphur Bank Mercury Mine Superfund Site, Lake County, California

Abstract.  Airborne geophysical reconnaissance was used to identify potential flow paths for mercury-rich, acidic water entering Clear Lake near the Sulphur Bank Mercury Mine. Airborne magnetic and electromagnetic conductivity surveys were conducted over a 12.3 km² (4.75 mi²) area that included the Oaks Arm of Clear Lake and the old mine. These surveys identified four magnetic and/or conductive anomalies that may represent groundwater conduits towards or away from the Herman Impoundment. An anomaly that extended from Herman Impoundment through a waste rock dam and into Clear Lake was selected for a more detailed ground electromagnetic conductivity survey. The combined results of the airborne and ground surveys provided a detailed, lateral depiction of conductive zones, the most probable pathways for groundwater flow. These surveys also identified near-surface areas that may contain elevated concentrations of sulfide minerals that weather to produce acid groundwater.     

Methods for Removing Signal Noise from Helicopter Electromagnetic Survey Data

Abstract.  A geophysical analysis was conducted over the abandoned T&T subsurface mines and portions of the Muddy and Roaring Creek watersheds in northeastern Preston County, West Virginia. The data were collected using helicopter-borne measurements of frequency-domain electromagnetic (FDEM) conductivity (390, 1555, 6254, 25,800, and 102,680 Hz). Noise was a significant issue in the lowest frequency EM conductivity data, especially the 390 Hz and 1555 Hz data; noise removal was accomplished by standard spatial frequency filtering, using homomorphic filters and Fourier filtering along individual flight lines. We interpret the filtered FDEM apparent conductivities and apparent resistivities as showing regions of potential mine pools and regions of contrasting groundwater conductivity related to discharge.     

Evaluation of Airborne Thermal Infrared Imagery for Locating Mine Drainage Sites in the Lower Youghiogheny River Basin,Pennsylvania, USA

Abstract.  Nighttime high-resolution airborne thermal infrared imagery (TIR) data were collected in the predawn hours during Feb 5-8 and March 11-12, 1999, from a helicopter platform for 72.4 km of the Youghiogheny River, from Connellsville to McKeesport, in southwestern Pennsylvania. The TIR data were used to identify sources of mine drainage from abandoned mines that discharge directly into the Youghiogheny River. Image-processing and geographic information systems (GIS) techniques were used to identify 70 sites within the study area as possible mine drainage sources. The combination of GIS datasets and the airborne TIR data provided a fast and accurate method to target the possible sources. After field reconnaissance, it was determined that 24 of the 70 sites were mine drainage. This paper summarizes: the procedures used to process the TIR data and extract potential mine-drainage sites; methods used for verification of the TIR data; a discussion of factors affecting the TIR data; and a brief summary of water quality.     

Using Helicopter Electromagnetic Surveys to Identify Environmental Problems at Coal Mines

Abstract.  Helicopter-mounted electromagnetic (HEM) surveys have been used to delimit conductive mine pools and groundwater features at various areas in the eastern United States that contain abandoned surface and underground coal mines. HEM was used to delineate the source areas and flow paths for acidic, metal-containing groundwater. This will aid remediation efforts. A recent HEM survey of Kettle Creek Watershed, Clinton County, Pennsylvania, using a 6-frequency electromagnetic data acquisition system, is presented. The survey accurately located conductive pools within underground mines, acidgenerating mine spoil at surface mines, and areas of groundwater recharge and discharge.     

Evaluation of Airborne Thermal Infrared Imagery for Locating Mine Drainage Sites in the Lower Kettle Creek and Cooks Run Basins,Pennsylvania, USA

Abstract.  High-resolution airborne thermal infrared (TIR) imagery data were collected over 90.6 km² (35 mi²) of remote and rugged terrain in the Kettle Creek and Cooks Run Basins, tributaries of the West Branch of the Susquehanna River in north-central Pennsylvania. The purpose of this investigation was to evaluate the effectiveness of TIR for identifying sources of acid mine drainage (AMD) associated with abandoned coal mines. Coal mining from the late 1800s resulted in many AMD sources from abandoned mines in the area. However, very little detailed mine information was available, particularly on the source locations of AMD sites. Potential AMD sources were extracted from airborne TIR data employing custom image processing algorithms and GIS data analysis. Based on field reconnaissance of 103 TIR anomalies, 53 sites (51%) were classified as AMD. The AMD sources had low pH (<4) and elevated concentrations of iron and aluminum. Of the 53 sites, approximately 26 sites could be correlated with sites previously documented as AMD. The other 27 mine discharges identified in the TIR data were previously undocumented. This paper presents a summary of the procedures used to process the TIR data and extract potential mine drainage sites, methods used for field reconnaissance and verification of TIR data, and a brief summary of water-quality data.