The role of fractures in regional groundwater flow : field evidence and model results from the basin-and-range of Texas and New Mexico

This study integrates fracture mapping and groundwater flow modeling to assess the role of fractures in regional groundwater flow. This is an important topic because fractures play a prominent role in groundwater flow in many aquifers. Furthermore, few studies have addressed quantitatively the regional hydrogeological implications of fractures. The study area is located in west Texas and southern New Mexico, between the Salt Basin and the Tularosa Valley. The region is largely undeformed, but the Permian carbonate bedrock is cut by many extensional faults and fractures. Air-photo analysis and field mapping reveal a broad fracture zone extending from the Sacramento Mountains to the Salt Basin near Dell City, Texas. Most fractures roughly parallel major normal faults and are oriented approximately N20W. The most intense fracturing coincides with a prominent trough in the potentiometric surface and an apparent "plume" of relatively fresh groundwater. Flow simulation and chemical modeling suggest that fracturing has created a high permeability zone that funnels recharge from the Sacramento Mountains at least 80 km southeastward to discharge points in the Salt Basin and the Dell City irrigation district. To estimate the regional transmissivity and to test the role of fractures in regional flow, a steady-state finite-element flow model was constructed in which fracture data are used to constrain a spatially distributed transmissivity. Given the probable range of recharge, discharge and other hydrologic parameters, fractures are the most important single constraint on the configuration of the potentiometric surface. Major results include: (1) fracturing can control groundwater flow over large (>1000 km²) areas, (2) effective recharge areas and regional groundwater chemistry trends are strongly influenced by fractures, and (3) through fracture studies, a priori inferences about aquifer properties and regional flow are possible. Finally, this study demonstrates one mechanism by which the timing and nature of tectonic events can affect regional subsurface fluid flow and, perhaps more importantly, related processes such as hydrothermal mineralization, diagenesis, and hydrocarbon transport and entrapment.Geological Science

Study of a High Voltage Ion Engine Power Supply

A complete laboratory breadboard version of a ion engine power converter was built and tested. This prototype operated on a line voltage of 80-120 Vdc, and provided output ratings of 1100 V at 1.8 kW, and 250 V at 20 mA. The high-voltage (HV) output voltage rating was revised from the original value of 1350 V at the beginning of the project. The LV output was designed to hold up during a 1-A surge current lasting up to 1 second. The prototype power converter included a internal housekeeping power supply which also operated from the line input. The power consumed in housekeeping was included in the overall energy budget presented for the ion engine converter. HV and LV output voltage setpoints were commanded through potentiometers. The HV converter itself reached its highest power efficiency of slightly over 93% at low line and maximum output. This would dip below 90% at high line. The no-load (rated output voltages, zero load current) power consumption of the entire system was less than 13 W. A careful loss breakdown shows that converter losses are predominately Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) conduction losses and HV rectifier snubbing losses, with the rectifier snubbing losses becoming predominant at high line. This suggests that further improvements in power efficiency could best be obtained by either developing a rectifier that was adequately protected against voltage overshoot with less snubbing, or by developing a pre-regulator to reduced the range of line voltage on the converter. The transient testing showed the converter to be fully protected against load faults, including a direct short-circuit from the HV output to the LV output terminals. Two currents sensors were used: one to directly detect any core ratcheting on the output transformer and re-initiate a soft start, and the other to directly detect a load fault and quickly shut down the converter for load protection. The finished converter has been extensively fault tested without failure. The finished converter has been packaged suitable for use as a laboratory prototype for further testing. The finished converter is readily transportable. An article on design issues for high voltage converters for ion engines is included as an attachement

Response of Long-Term Interest Rates to Overnight Interest Rates in the United States

The behavior of the long-term interest rates is a practical problem for private and public organizations. Organizations need to estimate interest rates for purposes of assigning value to long-term obligations such as defined benefit plans and long-term leases and making decisions related to long term capital purchases. The purpose of this study was to analyze the determinants of long-term interest rates in the United States, using 352 quarterly time series data points extending from 1999 to 2009. This study examines how a change in overnight interest rates, budget deficit, Gross Domestic Product (GDP), inflation, and net capital inflow impact on long-term interest rates, which is the 30-year U.S. Treasury constant securities rate. We find that the variables (overnight interest rates, expected inflation, budget deficit, foreign capital inflow, and GDP) have statistically significant impact on long-term interest rates in the United States; all variables jointly explain changes in the long-term interest rates. The findings of this study can assist organization as they assign values to long-term obligations and assets

Overcoming Barriers to Implementing Electronic Health Records in Rural Primary Care Clinics

Medicare-eligible physicians at primary care practices (PCP) that did not implement an electronic health record (EHR) system by the end of 2015 face stiff penalties. One year prior to the 2015 deadline, approximately half of all primary clinics have not implemented a basic EHR system. The purpose of this phenomenology study was to explore rural primary care physicians and physician assistants’ experiences regarding overcoming barriers to implementing EHRs. Complex adaptive systems formed the conceptual framework for this study. Data were collected through face-to-face interviews with a purposeful sample of 21 physicians and physician assistants across 2 rural PCPs in the southeastern region of Missouri. Participant perceptions were elicited regarding overcoming barriers to implementing EHRs systems as manadated by federal legislation. Interview questions were transcribed and processed through qualitative software to discern themes of how rural PCP physicians and physician assistants might overcome barriers to implementing electronic health records. Through the exploration of the narrative segments, 4 emergent themes were common among the participants including (a) limited finances to support EHRs, (b) health information exchange issues, (c) lack of business education, and (d) lack of change management at rural medical practices. This study may provide rural primary care physicians and administrators with strategies to promote the adoption of EHRs, provide cost efficient business services, and improve change management plans

Determinants Of Long-Term Interest Rates In The United States

The behavior of the long-term interest rates is a practical problem for private and public organizations.  Organizations need to estimate interest rates for purposes of assigning value to long-term obligations such as defined benefit plans and long-term leases and making decisions related to long term capital purchases.  The purpose of this study was to analyze the determinants of long-term interest rates in the United States, using 352 quarterly time series data points extending from 1999 to 2009.  This study examines how a change in overnight interest rates, budget deficit, Gross Domestic Product (GDP), inflation, and net capital inflow impact on long-term interest rates, which is the 30-year U.S. Treasury constant securities rate.  We find that the variables (overnight interest rates, expected inflation, budget deficit, foreign capital inflow, and GDP) have statistically significant impact on long-term interest rates in the United States; all variables jointly explain changes in the long-term interest rates.  The findings of this study can assist organization as they assign values to long-term obligations and assets

Response of Long-Term Interest Rates to Overnight Interest Rates in the United States

The behavior of the long-term interest rates is a practical problem for private and public organizations. Organizations need to estimate interest rates for purposes of assigning value to long-term obligations such as defined benefit plans and long-term leases and making decisions related to long term capital purchases. The purpose of this study was to analyze the determinants of long-term interest rates in the United States, using 352 quarterly time series data points extending from 1999 to 2009. This study examines how a change in overnight interest rates, budget deficit, Gross Domestic Product (GDP), inflation, and net capital inflow impact on long-term interest rates, which is the 30-year U.S. Treasury constant securities rate. We find that the variables (overnight interest rates, expected inflation, budget deficit, foreign capital inflow, and GDP) have statistically significant impact on long-term interest rates in the United States; all variables jointly explain changes in the long-term interest rates. The findings of this study can assist organization as they assign values to long-term obligations and assets

Improving Patient Safety through High Reliability Organizations

Preventable medical errors result in the loss of 200,000 lives per year with associated financial and operational burdens on organizations and society. Widespread preventable patient harm occurs despite increases in healthcare regulations. High reliability organization theory contributes to improved safety and may potentially reverse this trend. This single case study explored the introduction of a safety culture and subsequent improvements in patient safety in a reliability-seeking organization. Fourteen participants from a subacute nursing facility were selected using purposeful sampling criterion. Data were collected through participant interviews, document reviews, and group observation. Five themes emerged from an analysis of collected data including process standardization, checks and redundancy, authority migration, communication, and teamwork. The themes uncovered the need for extensive education and training, communication, and teamwork to improve patient safety. The results of the study may be useful to improve safety and enhance leadership to promote a culture of safe patient care

Overcoming Barriers to Implementing Electronic Health Records in Rural Primary Care Clinics

Medicare-eligible physicians at primary care practices (PCP) that did not implement an electronic health record (EHR) system by the end of 2015 face stiff penalties. One year prior to the 2015 deadline, approximately half of all primary clinics have not implemented a basic EHR system. The purpose of this phenomenology study was to explore rural primary care physicians and physician assistants’ experiences regarding overcoming barriers to implementing EHRs. Complex adaptive systems formed the conceptual framework for this study. Data were collected through face-to-face interviews with a purposeful sample of 21 physicians and physician assistants across 2 rural PCPs in the southeastern region of Missouri. Participant perceptions were elicited regarding overcoming barriers to implementing EHRs systems as manadated by federal legislation. Interview questions were transcribed and processed through qualitative software to discern themes of how rural PCP physicians and physician assistants might overcome barriers to implementing electronic health records. Through the exploration of the narrative segments, 4 emergent themes were common among the participants including (a) limited finances to support EHRs, (b) health information exchange issues, (c) lack of business education, and (d) lack of change management at rural medical practices. This study may provide rural primary care physicians and administrators with strategies to promote the adoption of EHRs, provide cost efficient business services, and improve change management plans

Candidate composite biomarker to inform drug treatments for diabetic kidney disease

Introduction: Current guidelines recommend renin angiotensin system inhibitors (RASi) as key components of treatment of diabetic kidney disease (DKD). Additional options include sodium-glucose cotransporter-2 inhibitors (SGLT2i), glucagon-like peptide 1 receptor agonists (GLP1a), and mineralocorticoid receptor antagonists (MCRa). The identification of the optimum drug combination for an individual is difficult because of the inter-, and longitudinal intra-individual heterogeneity of response to therapy. Results: Using data from a large observational study (PROVALID), we identified a set of parameters that can be combined into a meaningful composite biomarker that appears to be able to identify which of the various treatment options is clinically beneficial for an individual. It uses machine-earning techniques to estimate under what conditions a treatment of RASi plus an additional treatment is different from the treatment with RASi alone. The measure of difference is the annual percent change (ΔeGFR) in the estimated glomerular filtration rate (ΔeGFR). The 1eGFR is estimated for both the RASi-alone treatment and the add-on treatment. Discussion: Higher estimated increase of eGFR for add-on patients compared with RASi-alone patients indicates that prognosis may be improved with the add-on treatment. The personalized biomarker value thus identifies which patients may benefit from the additional treatment