Assessment of the 3,000 ppm and 10,000 ppm Total Dissolved Solids Boundaries in the Mississippian and Pennsylvanian Aquifers of Southwestern Indiana

Indiana Geological Survey Open-File Study 1994-2The Indiana Geological Survey (IGS), in cooperation with the Indiana Department of Natural Resources' Division of Oil and Gas, conducted a study of Mississippian and Pennsylvanian aquifers in southwestern Indiana to identify and depict the 3,000 and 10,000 ppm total dissolved solids (TDS) boundaries. Those boundaries, particularly the 10,000 ppm TDS level, are used to define the limits of aquifers denoted as Underground Sources of Drinking Water (USDW); under current federal regulations those aquifers are subject to protective measures to prevent contamination. The Indiana Division of Oil and Gas, as the primary state agency concerned with ensuring that USDWs are protected from contamination by the activity of the petroleum industry, has an ongoing interest to develop a regionally appropriate methodology. These data will facilitate the activity of the Division of Oil and Gas in the permitting and monitoring of various types of injection wells involved in secondary recovery and the subsurface disposal of oil field waters (Class II wells). Maps that show the structural configuration of the critical TDS boundaries within the petroleum-producing counties of southwestern Indiana, therefore, are highly useful. The TDS values for individual formations were obtained from two sources: actual brine samples, and from calculations utilizing resistivity and porosity readings from geophysical surveys that were run in petroleum industry wells. The data provided by over 2,500 oil and gas industry wells and approximately 10,000 individual-formation TDS calculations were used to make isosalinity maps. Maps depicting the elevations of the 3,000 and 10,000 ppm TDS boundaries were generated using the interpolated data from the log calculations and from brine samples. Five boreholes ranging from 449 ft to 609 ft were drilled and cored to calibrate the log evaluation techniques used. Each corehole was logged with a resistivity tool and a neutron/density device, which providing the same type of borehole evaluation data that was derived from petroleum industry wells used for calculation. TDS calculations were made from the logs on selected formations penetrated by the coreholes. The same zones were isolated by inflatable straddle packers, and actual samples of the formation waters were brought to the surface by a compressed-air operated pump. The water samples from 13 zones were analyzed using for TDS levels two different lab techniques and compared to log-derived calculated TDS values. None of the zones tested exceeded measured TDS levels of 2,000 ppm. The methodology was designed for saline fluids; the relatively low TDS levels and the presence of gas are though to be responsible for the reduced correlation found in the remaining fifty percent. The study demonstrated that TDS values derived from geophysical log can be used to predict salinity trends with reasonable reliability; however, exact TDS concentrations cannot be as reliably determined from log-derived data alone when formation fluids having salinities less than 5,000 ppm are present. It was also demonstrated that the 3,000 and 10,000 TDS ppm surfaces form generally basinward dipping surfaces that are much more irregular than anticipated. The 3,000 and 10,000 TDS surfaces occur in southwestern Indiana at greater depths than expected. Numerous salinity anomalies and salinity reversals or inversions were observed to exist within the study are. Those salinity anomalies and inversions can indicate several conditions, including the upwelling of deep fluids, faulting, and/or the circulation of more shallow subsurface fluids, and perhaps even the mixing of surface waters and the subsequent introduction into deep aquifers that normally would contain fluids of higher TDS levels.Indiana Department of Natural Resources, Division of Oil and Ga

AMPHIBIAN RESPONSE TO A LARGE-SCALE HABITAT RESTORATION IN THE PRAIRIE POTHOLE REGION

Over the next half-century, scientists anticipate that nearly one third of the currently recognized 7,450 amphibian species will become extinct. Many organizations have responded to the challenge of conserving amphibian biodiversity, some indirectly. Under the auspices of the Iowa Great Lakes Management Plan, the United States Fish and Wildlife Service, Department of Natural Resources, and their partners have been implementing habitat restoration efforts designed to protect water quality, provide recreational opportunities, and benefit wildlife at the regional level. With this program, over 130 wetlands have been created in the past 30 years on recently purchased public lands—one of the largest wetland restoration projects conducted in the Prairie Pothole Region of the Great Plains. While amphibians were not the main target of these restorations, we show that in response, 121 new breeding populations of native Northern Leopard Frogs (Lithobates pipiens; n = 80) and Eastern Tiger Salamanders (Ambystoma tigrinum; n = 41) have been established; in addition, we found 19 populations of non-native American Bullfrogs (L. catesbeianus). Using the program PRESENCE, we show that leopard frog occupancy was greatest in newer (<18 years old), intermediate-sized wetlands, and that tiger salamander occupancy was greatest in small wetlands without fish and larval bullfrogs. These data imply that because native amphibians responded positively to these newly established wetlands, habitat availability has likely been a factor in limiting population numbers. Further, these data suggest the presence of fishes and introduced bullfrogs interferes with the ability of tiger salamanders to colonize restored wetlands

Surgical site infection and transfusion rates are higher in underweight total knee arthroplasty patients.

BACKGROUND: Underweight (UW) patients undergoing total hip arthroplasty have exhibited higher complication rates, including infection and transfusion. No study to our knowledge has evaluated UW total knee arthroplasty (TKA) patients. We, therefore, conducted a study to investigate if these patients are at increased risk for complications, including infection and transfusion. METHODS: A case-control study was conducted using a prospectively collected institutional database. Twenty-seven TKA patients were identified as UW (body mass index [BMI] \u3c 18.5 kg/m RESULTS: The average BMI was 17.1 kg/m CONCLUSIONS: Our study demonstrates that UW TKA patients have a higher likelihood of developing SSI and requiring blood transfusions. The specific reasons are unclear, but we conjecture that it may be related to decreased wound healing capabilities and low preoperative hemoglobin. Investigation of local tissue coverage and hematologic status may be beneficial in this patient population to prevent SSI. Based on the results of this study, a prospective evaluation of these factors should be undertaken

The Morphological Effects of Two Antimicrobial Peptides, Hecate-1 and Melittin, on Escherichia Coli

The effects of the 26 amino acid, cationic, amphipathic, antibacterial peptide melittin and hecate-1, a 23 amino acid analog of it, on the gram negative bacterium Escherichia coli were investigated using scanning electron microscopy (SEM), transmission electron micros-copy (TEM), and freeze-fracture. Both peptides killed virtually all bacteria at the peptide concentration and cell density used. TEM and SEM revealed aggregates of bacteria entangled with material extruded from the bacterial surfaces. SEM revealed irregular bacterial surfaces with bleb-like projections. TEM and freeze-fracture indicate that the bacterial inner and outer membranes, as well as the peptidoglycan layer between, were extensively damaged. The cytoplasmic contents of the cells, however, did not appear radically disturbed, providing little evidence for osmotically induced cytolysis