bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reducing Inappropriate Hospital Use on a General Pediatric Inpatient Unit
Authors: Mahant Sanjay , Peterson Rishita , Campbell Maggie , MacGregor Daune L. , Friedman Jeremy N. 
Published: May 2008

OBJECTIVE. Studies have documented high rates of inappropriate hospital use in children. We assessed the effectiveness of an audit-and-feedback intervention at reducing inappropriate hospital days on a general pediatric inpatient unit.METHODS. A prospective observational study, using a before-and-after design, was conducted at a tertiary care pediatric hospital in Canada between March 2005 and August 2006. The appropriateness of all hospital days for all admissions was evaluated by a nurse trained in using a utilization review tool. This tool classifies hospital days as “qualified” or “nonqualified” on the basis of the nature of the inpatient services that are used. Reasons for nonqualified days were classified. The intervention consisted of (1) weekly feedback to attending physicians of which patients were nonqualified and (2) dissemination of summary reports to attending physicians. Comparisons were made between the preintervention (March 2005 to August 2005) and intervention (March 2006 to August 2006) phases.RESULTS. The intervention was associated with a significantly lower risk of inappropriate hospital days. Of the 7246 hospital days in the 6-month intervention phase, 2413 (33%) were nonqualified versus 3859 (47%) of 8228 hospital days in the 6-month preintervention phase. A total of 7.35 hospital days would have to be reviewed, combined with weekly feedback, to prevent 1 nonqualified hospital day. The 48-hour readmission rate in the intervention phase and preintervention phase was 1.0% and 1.6%, respectively. The proportion of nonqualified days to total hospital days that were attributable to “finishing intravenous antibiotics,” “awaiting tests,” “providing nutrition,” “observation only,” “tapering treatment,” and “teaching” decreased significantly, whereas the “lack of an alternate level of care” increased significantly.CONCLUSIONS. An audit-and-feedback intervention directed at attending physicians was associated with a lower risk of inappropriate hospital days without an increase in the readmission rate. The utilization review tool also identified processes that impact on inappropriate hospital days.
Early Marine Growth of Pink Salmon in Prince William Sound and the Coastal Gulf of Alaska During Years of Low and High Survival
Authors: Cross Alison D. , Beauchamp David A. , Myers Katherine W. , Moss Jamal H. 
Published: May 2008

AbstractAlthough early marine growth has repeatedly been correlated with overall survival in Pacific salmon Oncorhynchus spp., we currently lack a mechanistic understanding of smolt‐to‐adult survival. Smolt‐to‐adult survival of pink salmon O. gorbuscha returning to Prince William Sound was lower than average for juveniles that entered marine waters in 2001 and 2003 (3% in both years), and high for those that entered the ocean in 2002 (9%) and 2004 (8%). We used circulus patterns from scales to determine how the early marine growth of juvenile pink salmon differed (1) seasonally during May‐October, the period hypothesized to be critical for survival; (2) between years of low and high survival; and (3) between hatchery and wild fish. Juvenile pink salmon exhibited larger average size, migrated onto the continental shelf and out of the sampling area more quickly, and survived better during 2002 and 2004 than during 2001 and 2003. Pink salmon were consistently larger throughout the summer and early fall during 2002 and 2004 than during 2001 and 2003, indicating that larger, faster‐growing juveniles experienced higher survival. Wild juvenile pink salmon were larger than hatchery fish during low‐survival years, but no difference was observed during high‐survival years. Differences in size among years were determined by some combination of growing conditions and early mortality, the strength of which could vary significantly among years.
A Robust Deterministic Model Describing the Bomb Radiocarbon Signal for Use in Fish Age Validation
Authors: Hamel Owen S. , Piner Kevin R. , Wallace John R. 
Published: May 2008

AbstractThe bomb radiocarbon chronometer has become a standard tool for assessing the accuracy of otolith‐based fish age estimates. Use of the chronometer depends upon the increase in 14C that occurred due to the atmospheric testing of nuclear weapons in the middle of the 20th century. In previous analyses, a variety of ad hoc methods have been used to compare test chronologies with reference chronologies. This paper proposes a deterministic coupled‐functions model that describes bomb radiocarbon chronologies and standardizes and facilitates comparisons within and across species. In this model, a Gaussian pulse of radiocarbon over time is assumed, and dispersion and dilution are described by continuous exponential decay. The model simplifies to the product of a cumulative normal function and an exponential function; despite its simplicity, the model approximates the observed changes in oceanic radiocarbon quite well. It also allows for statistical testing of the timing of increase between different time series and thus permits quantitative aging validation as well as analysis of geographical differences in the timing of the bomb radiocarbon signal. Estimated model parameters describe the timing of the onset and temporal midpoint of the bomb‐related increase in 14C and the rate of 14C dispersion or dilution, which corresponds to the observed rate of decline during the postbomb period. Nine published chronologies are used to demonstrate the model and compare it with other published methods of summarizing bomb radiocarbon data for age validation purposes.
Downdip-Oil Potential for an Onshore Abu Dhabi Petroleum System
Authors: Pottorf R. J. , Hussenoeder K. L. , Petersen K. , Tseng H. , Davis C. L. , Richardson M. , Pietraszek-Mattner S. , Moore D. W. , El Agrab A. F. , Khouri A. A. 
Published: May 2008

Summary
A combination of fluid-inclusion and geochemical analyses was conducted on rocks and reservoir fluids to develop an improved understanding of downdip-oil potential in a mature exploration play, onshore Abu Dhabi, UAE. Exploration for oil in the region is complicated by low-permeability carbonate reservoirs, poor seismic imaging, and complex hydrocarbon-maturation and -migration histories. In addition, a broad range of fluid properties, including gas, condensate, and high-°API oil, makes evaluation of the reservoir fluid phase difficult.
In this challenging environment, geochemical and fluid-inclusion techniques are effective tools for identifying downdip oil potential from gas-cap fluids and reservoir-rock samples. Fluid-inclusion data are used to develop a hydrocarbon-emplacement history, which constrains the distribution of fluids throughout the exploration area. In some areas, undersaturated gas inclusions trapped at present-day temperatures suggest a low chance for downdip oil. Conversely, other structures contain oil inclusions that have been displaced recently by saturated gas, suggesting good potential for downdip oil. Geochemical analyses of recovered fluids were used independently to predict the likelihood of down-dip oil. These combined techniques were placed in a geologic framework to regionally risk the potential for downdip oil throughout the exploration area. This framework enables improved resource evaluation and prioritization of exploration efforts in areas of the play where a high probability of downdip oil exists.
Application of Integrated Reservoir Studies and Techniques To Estimate Oil Volumes and Recovery—Tengiz Field, Republic of Kazakhstan
Authors: Dehghani K. , Jenkins S. , Fischer D. J. , Skalinski M. 
Published: May 2008

Summary
Recent technical studies and probabilistic techniques have been integrated to build reservoir models for Tengiz field. Tengiz is one of the deepest supergiant oil fields in the world and is on the shore of the Caspian Sea within the Republic of Kazakhstan. Knowledge of the uncertainties inherent in oil recovery is a key to proper reservoir management of this important oil field.
Probabilistic techniques gave insights into the importance and ranking of key reservoir uncertainties. This ranking is used to reduce reservoir uncertainties and to guide reservoir management activities.
A structured Monte Carlo Technique has been used to construct several thousand static models of Tengiz field. Construction of Monte-Carlo models is fast and allows the impact of key uncertainties to be explored. Static reservoir uncertainties investigated include wireline log calibration, structural elevation, geostatistical parameters (such as variogram length), water saturation, and location of the boundary between facies intervals.
Investigating the uncertainty in the dynamic performance of the model is computationally intensive. Experimental design techniques were used to minimize the number of computationally expensive simulation runs. Key dynamic variables investigated include: oil in place (OIP), gas/oil relative permeability, permeability enhancements, vertical-to-horizontal permeability ratio, well productivity, the water/oil contact (WOC) depth, and production capacity.
The methodology for generating the range of possible outcomes for some development scenarios in Tengiz is discussed here. The application of Monte Carlo and experimental design techniques to identify the high impact static and dynamic parameters is reviewed.
The construction of a probabilistic distribution of OIP and recoveries is demonstrated for one development alternative for Tengiz field. This study found that for this development alternative, the OIP, gas/oil relative permeability, and ratio of vertical to horizontal permeability have the greatest impact on the estimated oil recoveries.
Modeling Dependence Among Geologic Risks in Sequential Exploration Decisions
Authors: Bickel J. Eric , Smith James E. , Meyer Jennifer L. 
Published: May 2008

SummaryProspects in a common basin are likely to share geologic features. For example, if hydrocarbons are found at one location, they may be more likely to be found at other nearby locations. When making drilling decisions, we should be able to exploit this dependence and use drilling results from one location to make more informed decisions about other nearby prospects. Moreover, we should consider these informational synergies when evaluating multiprospect exploration opportunities. In this paper, we describe an approach for modeling the dependence among prospects and determining an optimal drilling strategy that takes this information into account. We demonstrate this approach using an example involving five prospects. This example demonstrates the value of modeling dependence and the value of learning about individual geologic risk factors (e.g., from doing a postmortem at a failed well) when choosing a drilling strategy.
An Accurate Method for Determining Oil PVT Properties Using the Standing-Katz Gas Z-Factor Chart
Authors: Sutton Robert P. 
Published: May 2008

SummaryAn accurate technique for estimating oil pressure/volume/ temperature (PVT) properties using the Standing-Katz Z-factor chart has been developed. Prior work to derive tuned gas-pseudocritical-property values that provide consistent and accurate compressibility factors has been extended to oils.Data from 1,099 worldwide oil PVT reports with 11,960 density measurements have been analyzed. The oils studied have API gravities ranging from 10.6 to 63, with gas/oil ratios ranging from 5 to 4,631 scf/STB. Bubblepoint formation volume factors (FVFs) range from 0.98 to 4.58 bbl/STB. Saturation pressures ranged from 60 to 10,326 psia at temperatures ranging from 50 to 332°F with pressure differentials to 18,491 psi.The resulting work shows that oil pseudocritical properties can be correlated with molecular weight, as with gases. The resulting relationships can be used to determine saturated-and undersaturated-oil density accurately. Oil PVT properties, such as FVF and isothermal compressibility, can then be derived from fundamental relationships with density.Because the new method correlates properties with the molecular weight of the wellstream, the chemical nature of the oil (e.g., whether naphthenic or paraffinic) is considered. Existing correlations (30 for bubblepoint oil FVF and 17 for isothermal compressibility) have been identified in the literature. These methods are tested against the database along with the new method to determine accuracy and recommended procedures. Isothermal oil compressibility has proved difficult to correlate historically, with errors typically in excess of 30%. The proposed method significantly reduces the error in calculated isothermal compressibility in comparison to traditional methods.
Simulation of Inflow While Underbalanced Drilling With Automatic Identification of Formation Parameters and Assessment of Uncertainty
Authors: Friedel Torsten , Mtchedlishvili George , Voigt Hans-Dieter , Häfner Frieder 
Published: May 2008

Summary
Underbalanced drilling (UBD) is defined as a drilling operation in which the pressure of the circulating drilling fluid is lower than the pore pressure of the target formation of interest. The most widely recognized benefit of UBD is the reduction of formation damage by minimizing the drilling-mud leakoff and fines migration into the formation. It also facilitates the possibility for reservoir characterization during drilling. The purpose of this paper is to present (1) how to use the inflow data for the evaluation of formation properties, and (2) how to cope with the uncertainty of the results.
An in-house multiphase reservoir simulator is used for the simulation of the formation reservoir-fluid flow during UBD. The model incorporates discrete consideration of the well with appropriate time-varying UBD boundary conditions. Capillary forces, which facilitate countercurrent imbibition of the drilling mud into the formation, are taken into account.
The production rates during UBD depend on the formation properties and the drilling conditions. The inflow information is analogous to transient test data and can be used for the estimation of the reservoir-model parameters. With the progression of the drilling process, the amount of available inflow data increases and allows for a sequential history-match procedure. Statistical analysis of the inverse problem can then be utilized to determine the optimal level of parameterization that is justified by the quality and quantity of the measured data.
This paper highlights (1) the use of a reservoir simulator to derive the inflow of fluids in heterogeneous reservoirs, and (2) its coupling with gradient-based optimization techniques for determination of unknown reservoir parameters. The simulation-whiledrilling approach proposed is fully automated and can be set up on a known or totally unknown reservoir model, introducing an iterative and automatic updating process of the reservoir model.
Production Optimization With Adjoint Models Under Nonlinear Control-State Path Inequality Constraints
Authors: Sarma Pallav , Chen Wen H. , Durlofsky Louis J. , Aziz Khalid 
Published: May 2008

Summary
The general petroleum-production optimization problem falls into the category of optimal control problems with nonlinear control-state path inequality constraints (i.e., constraints that must be satisfied at every time step), and it is acknowledged that such path constraints involving state variables can be difficult to handle. Currently, one category of methods implicitly incorporates the constraints into the forward and adjoint equations to address this issue. However, these methods either are impractical for the production optimization problem or require complicated modifications to the forward-model equations (the simulator). Therefore, the usual approach is to formulate this problem as a constrained nonlinear-programming (NLP) problem in which the constraints are calculated explicitly after the dynamic system is solved. The most popular of this category of methods for optimal control problems has been the penalty-function method and its variants, which are, however, extremely inefficient. All other constrained NLP algorithms require a gradient for each constraint, which is impractical for an optimal control problem with path constraints because one adjoint must be solved for each constraint at each time step in every iteration.
The authors propose an approximate feasible-direction NLP algorithm based on the objective-function gradient and a combined gradient for the active constraints. This approximate feasible direction is then converted into a true feasible direction by projecting it onto the active constraints and solving the constraints during the forward-model evaluation itself. The approach has various advantages. First, only two adjoint evaluations are required in each iteration. Second, the solutions obtained are feasible (within a specified tolerance) because feasibility is maintained by the forward model itself, implying that any solution can be considered a useful solution. Third, large step sizes are possible during the line search, which may lead to significant reductions in the number of forward-and adjoint-model evaluations and large reductions in the magnitude of the objective function. Through two examples, the authors demonstrate that this algorithm provides a practical and efficient strategy for production optimization with nonlinear path constraints.
Pharmacokinetics of butorphanol tartrate in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus)
Authors: Riggs Shannon M. , Hawkins Michelle G. , Craigmill Arthur L. , Kass Philip H. , Stanley Scott D. , Taylor Ian T. 
Published: May 2008

Abstract
Objective—To determine the pharmacokinetics of butorphanol tartrate after IV and IM single-dose administration in red-tailed hawks (RTHs) and great horned owls (GHOs).
Animals—6 adult RTHs and 6 adult GHOs.
Procedures—Each bird received an injection of butorphanol (0.5 mg/kg) into either the right jugular vein (IVj) or the pectoral muscles in a crossover study (1-week interval between treatments). The GHOs also later received butorphanol (0.5 mg/kg) via injection into a medial metatarsal vein (IVm). During each 24-hour postinjection period, blood samples were collected from each bird; plasma butorphanol concentrations were determined via liquid chromatography-mass spectrometry.
Results—2- and 1-compartment models best fit the IV and IM pharmacokinetic data, respectively, in both species. Terminal half-lives of butorphanol were 0.94 ± 0.30 hours (IVj) and 0.94 ± 0.26 hours (IM) for RTHs and 1.79 ± 1.36 hours (IVj), 1.84 ± 1.56 hours (IM), and 1.19 ± 0.34 hours (IVm) for GHOs. In GHOs, area under the curve (0 to infinity) for butorphanol after IVj or IM administration exceeded values in RTHs; GHO values after IM and IVm administration were less than those after IVj administration. Plasma butorphanol clearance was significantly more rapid in the RTHs. Bioavailability of butorphanol administered IM was 97.6 ± 33.2% (RTHs) and 88.8 ± 4.8% (GHOs).
Conclusions and Clinical Relevance—In RTHs and GHOs, butorphanol was rapidly absorbed and distributed via all routes of administration; the drug's rapid terminal half-life indicated that published dosing intervals for birds may be inadequate in RTHs and GHOs.
Histologic and micro–computed tomographic evaluation of the osseointegration of a nonresorbable bone substitute in alveoli of ponies after tooth extraction
Authors: Vlaminck Lieven , Cnudde Veerle , Pieters Koen , Van Den Broeck Wim , Steenhaut Michel , Jacobs Patric , Gasthuys Frank 
Published: May 2008

Abstract
Objective—To evaluate the biological behavior of a nonresorbable bone substitute (NRBS) in the alveoli of ponies, compared with tissue quality in naturally healing alveoli, after cheek tooth extraction.
Animals—5 clinically normal ponies.
Procedures—In each pony, both maxillary fourth premolars (Triadan 108/208) were repulsed bilaterally during anesthesia. One randomly chosen alveolus was filled with NRBS and isolated from the oral cavity by use of dental impression material and a spring-wire retention device. The other alveolus was occluded in its occlusal third portion with dental impression material. One year after surgery, cylindrical lateromedial biopsy specimens were collected from the apical, middle, and occlusal level of each alveolus. Biopsy samples were evaluated for bone mineral density and bone volume via micro–computed tomography; qualitative histologic characteristics were evaluated via light microscopy.
Results—Bone mineral density and bone volume were greater in control alveoli, compared with NRBS-treated alveoli. Control alveoli were characterized by the presence of few mature bone trabeculae and wide spaces containing fat tissue and mesenchymal stroma. In treated alveoli, biocompatibility and osteoconductive properties of the NRBS were excellent; continuous bone formation and bone remodeling were also evident.
Conclusions and Clinical Relevance—Results indicated that the NRBS was integrated well in calcified alveolar tissues in ponies 1 year after maxillary cheek tooth extraction. Further research is necessary to establish the benefits of this NRBS in the development of a dental implant surgical technique in equids.
Evaluation of technetium Tc 99m–labeled biotin for scintigraphic detection of soft tissue inflammation in horses
Authors: Kleine Lauren G. , Solano Mauricio , Rusckowski Mary , Hunt Kathleen E. , Johnson Karen L. , Kirker-Head Carl A. 
Published: May 2008

Abstract
Objective—To evaluate the use of technetium Tc 99m–labeled EDTA-biotin monomer (99mTc-EB1) as a scintigraphic imaging agent for soft tissue inflammatory lesions in horses.
Animals—6 healthy adult horses.
Procedures—First (phase 1), the agent's safety and blood-tissue clearance and an appropriate imaging protocol were determined in 6 horses. Each horse was injected with 99mTc-EB1 (1.1 GBq, IV, once); images were acquired at intervals during the following 24-hour period. Subsequently (phase 2), inflammation was induced via injection of 200 mg (10 mL) of mepivacaine (0.4 mg/kg) into the right neck musculature and perineurally in the proximal palmar metacarpal region of the right forelimb of 2 horses. Six hours after mepivacaine injection, 99mTc-EB1 (2.2 GBq, IV, once) was administered; 8 hours after injection, comparative soft tissue images were acquired after administration of technetium 99mTc-hydroxymethylene diphosphonate (99mTc-HDP; 7.4 GBq, IV, once).
Results—After injections of 99mTc-EB1, physical examinations, CBCs, and serum biochemical analyses revealed no abnormalities in any horse. Blood clearance of 99mTc-EB1 was rapid (A phase, 2.2 minutes; β phase, 58 minutes). Soft tissue uptake of 99mTc-EB1 was immediate and persisted for as long as 4 hours after injection. At 6 hours after IM and perineural mepivacaine injections, mepivacaine-induced inflammation was detectable by use of 99mTc-EB1.
Conclusions and Clinical Relevance—Results indicated that 99mTc-EB1 is safe for use in horses and can identify soft tissue inflammation without concurrent uptake in bone. Compared with 99mTc-HDP administration, use of 99mTc-EB1 extended the duration of soft tissue scintigraphic image acquisition.