bluuebunny/crossref_metadata_2025 huggingface dataset:
Case Study: Evaluation of Regional Lithology for Carbon Dioxide Storage Using a Single Test Well in Southeastern Ohio
Authors: Meggyesy S. D. , Jagucki P. E. , Gerst J. , Place M.
Published: October 2008

The purpose of this project is to investigate the feasibility of carbon sequestration using information gathered from a single test well at a coal-fired power plant in the Appalachian Basin. The effort to date includes site selection, preliminary test design and implementation, and development of data objectives consistent with overall program goals. An iterative approach was implemented to enhance our understanding of the local and regional geologic conditions and limits at each stage. First steps included building a geologic model of injection and caprock formations based on regional well logs and other existing data as well as performing a 2-D surface seismic survey around the proposed well location. This information was then used to design the stratigraphic test well and data collection methodology. The test well was drilled in early 2007 and completed in January 2008. Wireline logs and rock samples collected during the drilling are being used to refine the geologic model and to develop plans for the injection tests scheduled for fall 2008. The site is one of the three locations selected for testing geologic storage of CO2 under the Midwestern Regional Carbon Sequestration Program (MRCSP) led by Battelle.

Information collected to date is being analyzed to indicate the potential for carbon sequestration in regional reservoirs. In general, the reservoirs are well-contained with good caprock. Drilling, logging, and collection and laboratory testing of sidewall cores have provided the data to design injection tests in up to three potential injection targets between approximately 5,000 and 8,000 feet below ground surface. Approximately 3,000 tons of supercritical-phase CO2 is planned to be injected in these formations. Targets include a Lower Silurian sandstone known regionally as a gas-producer; Silurian sequences consisting of interbedded layers of halite, anhydrite, limestone, and porosity-preserving dolomite; and a Lower Devonian sandstone. The upcoming injection tests will help to further refine local and regional injectivity and capacity in the target reservoirs; caprock integrity, and single-well monitoring techniques.

Field projects like this add to knowledge and understanding of how to select and characterize potential injection reservoirs, establish familiarity of the technology with the public and regulatory agencies, and aid in the selection of appropriate testing and monitoring techniques for each location.
Uncovering and Exploiting Existing Marcellus Shale Opportunities in the Appalachian Basin
Authors: Suhy T. E.
Published: October 2008

The developing interest in the Northeast Marcellus Shale play has led to a flood of lease acquisition activity not seen in many years. Competitive acreage positioning and rumors of huge delayed rentals, large signing bonuses, and generous buy-outs are reminiscent of the boom years in the early 1980's. Most of the potential affordable assets have already been locked up and the small or medium size operator has either been priced out or crowded out.

Those operators may not be as far behind the rush as they may fear. The nature of oil field culture has led to the Marcellus and other shale formations being ignored for years and viewed as more of a drilling nuisance than as a valuable play. As a result, it has been drilled to, drilled through, cased through and generally avoided for as long the Devonian Sands have been developed in the Appalachian Basin. In a few cases where shale stimulations were attempted, they were poorly designed and marginally effective which kept the interest very limited.

The oil field culture of past decades allowed many of these resources to remain hidden and underdeveloped. These assets can now be "Re-Discovered" through a variety of record resource reviews, re-drilling and re-completion techniques, spacing analysis, and general detective work.

This paper will explore a variety of techniques that both major and independent operators can use to take advantage of their existing underdeveloped assets.
A New Algorithm for Rachford-Rice for Multiphase Compositional Simulation
Authors: Okuno R. , Johns R. T. , Sepehrnoori K.
Published: October 2008

Flash calculations for use in compositional simulation are more difficult and time-consuming as the number of equilibrium phases increase beyond two. Because of its complexity many simulators do not even attempt to incorporate three or more hydrocarbon phases even though such cases are important in many low-temperature gas floods, or for high temperatures where hydrocarbons can partition into water. Multiphase flash algorithms typically use successive substitution (SS) followed by Newton's method. For NP-phase flash calculations, (NP-1) Rachford-Rice (RR) equations are solved in every iteration step in SS, and depending on the choice of independent variables, in Newton's method. Solution of RR equations determines both compositions and amounts of phases for a fixed overall composition and set of K-values. A robust algorithm for RR is critical to obtain convergence in multiphase compositional simulation, and has not been satisfactorily developed unlike the traditional two-phase flash. In this paper, we develop a robust and efficient algorithm for RR equations for multiphase compositional simulation.

We focus primarily on systems with three equilibrium hydrocarbon phases, although other applications are possible. We derive a function, whose gradient vector consists of RR equations. This correct solution to the RR equations is formulated as a minimization of the non-monotonic convex function using the independent variables of (NP-1) phase mole fractions. The key to obtaining a robust algorithm is that we specify non-negative constraints for the resulting equilibrium phase compositions, which are described by a very small region with no poles. The minimization uses Newton's direction with a line search technique to exhibit super-linear convergence. We show a case in which a previously developed method cannot converge while our algorithm rapidly converges in a few iterations. We implement the algorithm both in a stand-alone flash code and in UTCOMP, a multiphase compositional simulator, and show that the algorithm is guaranteed to converge when a multiphase region exists as indicated by stability analysis.
Optimized Design of Cyclic Pressure Pulsing in a Depleted, Naturally Fractured Reservoir
Authors: Artun E. , Ertekin T. , Watson R. , Miller B.
Published: October 2008

Gas cyclic pressure pulsing is an effective IOR method specifically for naturally fractured reservoirs. Due to the computational cost of simulating a large number of scenarios, it is an arduous task to determine the optimum operational conditions for the process. In this study, a practical screening and optimization workflow is utilized to determine the most optimum operating conditions for cyclic pressure pulsing applications with N2 and CO2 in a fully-depleted reservoir. Two huff ‘n’ puff design schemes with variable and constant injection volumes are implemented in a compositional, dual-porosity reservoir simulation model. A set of representative design scenarios is created and run using this model. Then, the collected performance indicators are fed into the neural network for training and two neural network-based proxies are developed: 1) A forward proxy to predict the corresponding performance indicators once given the design scenarios, 2) An inverse proxy to predict the corresponding design scenarios once given a set of desired performance characteristics. Finally, the genetic algorithm is used to search for the best design scenario that would maximize the efficiency of the process for a given time of operation. To evaluate the objective function, the forward proxy is used for computational efficiency. The methodology is tested with a single-well reservoir model of the Big Andy Field which is a depleted, naturally fractured reservoir in Eastern Kentucky with stripper-well production. Predictive capability and accuracy of developed networks are checked by comparing simulation outputs with network outputs. It is observed that networks are able to accurately predict the performance indicators including the peak rate, time to reach the peak rate, cycle flow rates, incremental oil production, and gas-oil-ratio. The proposed methodology is practical and computationally efficient in structuring more effective decisions towards the optimum design of the process.
Water Quality: Is it Important for Cement?
Authors: Rowan T. M. , Stone M. L.
Published: October 2008

In this paper, the relationship between cement mix water quality and cement quality are investigated. Water quality will be tested for chlorides, calcium and magnesium, pH, and alkalinity. Full API analysis will be used to compare the effects that different concentrations of the aforementioned components have on cement properties.

Each component previously mentioned will be measured out at specific concentrations in the water. The water will then be used to mix a cement slurry according to API Specification 10. After the slurry is blended, a battery of tests will be run including thickening time, viscosity, compressive strength, free water and fluid loss. Each parameter will then be compared to the results of the cement slurry that was mixed using distilled or de-ionized water. We will also look at the effects of all the "additives" included in the water sample used to mix the cement and any change they have made to the properties of each blend.

This is mainly a study for quality control purposes. We are taking a look at what the limits for specific elements are and what their influence is on certain cement properties. These analyses will help us determine if slurry being considered is suitable for any particular job proposal. This will also enhance our quality control measures and improve our stance on customer satisfaction, which is always our main goal.
Cooperative Optimization-Based Dimensionality Reduction for Advanced Data Mining and Visualization
Authors: Chen D. , Hamid S. , Dix M. , Quirein J. , Jacobson L. , Hollingsworth M.
Published: October 2008

Dimensionality reduction in advanced data mining is often a non-linear problem, and the method used to resolve the dimensionality reduction will typically include:

Definition of the objective function to preserve essential information of the original data Specification of the algorithm to optimize the sample mapping from a high-dimensional (HD) space to a low-dimensional (LD) space Determination of the transformation scheme that can be applied to unseen new data.

In practice, a data-driven approach that maximizes the sample pair distance match of the original data and the transformed data is usually used. But, the sample mapping optimization and new data transformation are often determined in diverse domains.

This paper provides a hybrid method to determine the appropriate data transformation from an original HD space to an output LD space, usually 2D or 3D space, with minimal information loss. This method is fundamentally a cooperative optimization algorithm combining more than one computational intelligence paradigm. Basically, given the problem data in a HD space, the proposed method first applies evolutionary computation (EC) to determine the LD output values, and then, performs particle swarm optimization (PSO) to refine the results. The data conversion scheme is implemented by a neural network ensemble using the EC-PSO-derived LD outputs as training targets. This method has better capability to tackle problems of local minima and to produce robust conversion of the new data. To make the preserved information essential to the user, multi-objective fitting for advanced data exploration is embedded into this method.

In this paper, both the theoretical background of the developed method and the procedures applied to high-dimensional data visualization, feature extraction, and cluster analyses are discussed. Two case studies with simulated and field data to demonstrate potential applications in reservoir characterization and predictive modeling are also presented. The results strongly justify using a cooperative optimization approach to improve data mapping (especially in handling large data sets), and suggest that the method shows promise as being an effective standard procedure to help automate high-dimensional data processing.
Determination of Relative Permeability and Capillary Pressure Curves Using an Automated History-Matching Approach
Authors: Basbug B. , Karpyn Z. T.
Published: October 2008

The efficiency of hydrocarbon recovery from oil and gas reservoirs is mainly controlled by our ability to understand and define fluid transport properties, such as relative permeability and capillary pressure. This study focuses on the development and implementation of a numerical model of multiphase flow in a fractured core sample by establishing a proper physical framework that describes the capillary pressure-relative permeability characteristics. An automated history matching approach is proposed to determine relative permeability and capillary pressure curves consistent with a core flood reservoir model performance. The automated history matching approach relies on a commercial reservoir simulator coupled with an optimization protocol. A large-scale ‘Trust Region Method’ that minimizes the objective function is implemented for the adjustment of parameters controlling the relative permeability and capillary pressure curves. The objective function is defined as the non-linear least square representation of the difference between estimated and obtained fluid saturation distributions from a core flood reservoir model. The results indicate that the proposed approach successfully predicts relative permeability and capillary pressure curves of a fractured core sample which provides a foundation for field-scale history matching with simultaneous estimation of transport properties.
The Effect of Carbonic Acid on Well Cements as Identified through Lab and Field Studies
Authors: Duguid A.
Published: October 2008

In the United States carbon capture and storage as a means of emissions mitigation is moving towards commercial implementation. In anticipation of large numbers of CCS sites coming online it is important to understand wells as potential leakage pathways and identify existing technologies that can measure and monitor the integrity of wells that are exposed to CO2. Well integrity is important because wells and the annuli and pathways that may exist within them can act as leakage pathways for CO2 back to the surface or as conduits for leakage between formations. Studies related to the integrity of wells have been conducted on well cements created in both the laboratory and in the field. This paper will discuss recent laboratory and field work, the differences between the results of the two types of experiments, and how the results of the two are not contradictory but are due to differing conditions between the lab and the field. This paper will also discuss how the results of field measurements can be used to identify the types and combinations of tools that may be used to detect wellbore integrity problems in future.
Development and Testing of an Expert System for Coalbed Methane Reservoirs Using Artificial Neural Networks
Authors: Srinivasan K. , Ertekin T.
Published: October 2008

Reservoir simulators are effectively used in predicting the production performances of oil and gas reservoirs within a good level of accuracy. However, during initial stages of exploitation, our knowledge on most of the reservoir properties and production parameters involve a good degree of uncertainty. In such cases, expert systems can be effective as a screening tool by mimicking the performance of a reservoir simulator at a lower cost and reduced personnel and machine time. The expert system described in this paper is a tool which can be used to predict the performance of a coalbed methane reservoir similar to its numerical counterparts.

The proposed expert system has been trained with the help of an extensive data base and has the capability of providing gas and water production profiles for a period of about ten years for a given coalbed methane reservoir. Other outputs include cumulative gas and water production, peak gas flow rate expected, time to achieve a peak rate and abandonment time. This study also involves the development of an inverse expert system which has the capability of identifying the optimum production strategies for a desired production scenario from a coalbed reservoir. Conventional reservoir simulators cannot suggest an optimized design strategy that can help achieve a certain desired production performance from a coal seam unless a large number of scenarios are studied. The inverse model can tackle this optimization problem quite effectively.
Exploring Surface Collected Data with Spatial Analysis Methods
Authors: Bradbury Andrew P. , Anderson Jason M. , Allgood Jessica L. , Richmond Michael D. , Rotman Deborah L.
Published: October 2008

Surface collection is commonly conducted as a first step in the investigation of many archaeological sites. Such data are often used to provide information concerning the subsurface nature of the site. In some instances, the surface collected data can provide additional information concerning the site component(s) represented at a site. In cases where intact cultural deposits are not present below the base of the plow zone, surface collected data may represent the only chance of understanding the site. In this article, we apply spatial analysis methods to surface collection data from two prehistoric sites (15Hr14 and 15FL104) in Kentucky. By combining the results of the spatial analysis with that of the lithic analysis, additional data concerning both sites are brought to light.
A Network-of-Voids Model to Assess Wall Flow Patterns and Heat Transfer for Low Aspect Ratio Packed-Bed Reactors
Authors: Chigada Peter I , Mann Reginald
Published: October 2008

Exothermic packed bed catalytic reactors are usually characterised by a low diameter-aspect ratio to facilitate heat transfer. In operation, these reactors often exhibit localized regions with much higher temperatures referred to as hot spots. A new model based on a 2-D network-of voids (NoV) has been devised to explore wall heat transfer behaviour for such low aspect ratio packed tubes. Random placement of (packing) particles is used to provide a simple NoV framework for implicitly creating the tortuous fluid flows amongst the resulting randomized inter-connecting voids. This is a computationally tractable strategy for exploring the haphazard appearance of individual tube pin-hole burn-outs amongst the typically thousands, or tens of thousands, of tubes within high temperature industrial multi-tubular configurations. Although presently limited to 2-D, the model captures many natural features of the flow and heat transfer of randomly packed tubes, especially huge variations in wall and cross flows and consequently massive variations in local wall heat transfer coefficients along the length of individual tubes. The model is potentially superior to those based upon averaged properties, which do not properly distinguish the solid and fluid phases. The network-of-voids concept is readily extended to 3-D, in order to achieve geometric congruence of the model and assemblies of individual particles.
An Adaptive Smart Sensor Network for Overhead Lines Thermal Rating Prediction
Authors: Vaccaro Alfredo , Villacci Domenico
Published: October 2008

The need for dynamic loading of overhead lines requires reliable assessment tools that should be able to predict both the evolution of the hot-spot temperature and the associated maximum allowed duration, at any load level and on the basis of the actual conductor thermal state and environmental conditions. In order to address this problem, the paper proposes the employment of a smart sensor network distributed along the line route. Each network's node, starting from on-line measurements, assesses, by an indirect method of parameter identification, the value of the main variables which regulate the heat exchange between the conductor and its surrounding. Then, starting from these data, each node calculates the load capability curve by solving iteratively a built in dynamic thermal model and transmits the results to a central server by a cooperative based communication paradigm. To assess the performances of the proposed solution, experimental studies obtained on a laboratory overhead line are presented and discussed.
Unit Commitment of Hydro Dominated Systems
Authors: Arce Encina Anastacio Sebastian , Soares Secundino , Ohishi Takaaki , Cicogna Marcelo Augusto
Published: October 2008

This paper is concerned with the unit commitment of hydro generating units on an hourly basis throughout a single day. A performance criterion that takes into consideration variations in tailrace elevation, penstock head loss and turbine-generator efficiency is suggested as the objective function for the optimization model. A heuristic procedure based on Lagrangian Relaxation was implemented to solve the problem. The approach was then tested on a system composed of sixteen hydro plants, one hundred generating units, and an installed capacity of 21,933 MW, in the Brazilian power system. The scheduling of generation verified for a typical day was used for comparison with the solution proposed by this procedure. The results show a significant improvement in terms of hydro conversion efficiency.
Application of Fuzzy Fault-Tree Analysis to Assess the Reliability of a Protection System for a Switchyard
Authors: Hong Ying-Yi , Lee Lun-Hui , Cheng Heng-Hsing
Published: October 2008

This paper proposed a method for reliability assessment of the protection system for a switchyard by fault-tree analysis considering uncertainty of unavailability for an element. Unavailability of an element with uncertainty is expressed with the fuzzy set. The fault-tree analysis incorporated with the fuzzy set is employed to conduct the reliability assessment. The importance of elements influencing reliability can be achieved by the Fuzzy Importance Measure. Compared with traditional methods, the fault-tree analysis requires less computation. In this paper, a 345 kV switchyard in the 3rd nuclear power plant in Taiwan serves as an example for illustrating the results of the proposed method.
Use of a Deformation Coefficient for Transformer Winding Diagnostics
Authors: Joshi Prasad M , Kulkarni S V
Published: October 2008

This paper presents a novel method for deformation diagnostics of transformer windings using terminal measurements. The shortcomings of existing practices in locating deformation and determining its extent are discussed. The logical steps involved in devising the new method are elaborated. The effectiveness of Deformation Coefficient (DC) in locating the deformed winding section is demonstrated. Comparison of experimental results, on a model winding, with simulation studies is presented.
Angiogenesis Associated With Visceral and Subcutaneous Adipose Tissue in Severe Human Obesity
Authors: Ledoux Séverine , Queguiner Isabelle , Msika Simon , Calderari Sophie , Rufat Pierre , Gasc Jean-Marie , Corvol Pierre , Larger Etienne
Published: October 2008

OBJECTIVE—The expansion of adipose tissue is linked to the development of its vasculature. However, the regulation of adipose tissue angiogenesis in humans has not been extensively studied. Our aim was to compare the angiogenesis associated with subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from the same obese patients in an in vivo model.

RESEARCH DESIGN AND METHODS—Adipose tissue samples from visceral (VAT) and subcutaneous (SAT) sites, obtained from 36 obese patients (mean BMI 46.5 kg/m2) during bariatric surgery, were layered on chick chorioallantoïc membrane (CAM).

RESULTS—Both SAT and VAT expressed angiogenic factors without significant difference for vascular endothelial growth factor (VEGF) expression. Adipose tissue layered on CAM stimulated angiogenesis. Angiogenic stimulation was macroscopically detectable, with engulfment of the samples, in 39% and was evidenced by angiography in 59% of the samples. A connection between CAM and adipose tissue vessels was evidenced by immunohistochemistry, with recruitment of both avian and human endothelial cells. The angiogenic potency of adipose tissue was not related to its localization (with an angiogenic stimulation in 60% of SAT samples and 61% of VAT samples) or to adipocyte size or inflammatory infiltrate assessed in adipose samples before the graft on CAM. Stimulation of angiogenesis by adipose tissue was nearly abolished by bevacizumab, which specifically targets human VEGF.

CONCLUSIONS—We have established a model to study the regulation of angiogenesis by human adipose tissue. This model highlighted the role of VEGF in angiogenesis in both SAT and VAT.
Upregulation of Mitochondrial Uncoupling Protein-2 by the AMP-Activated Protein Kinase in Endothelial Cells Attenuates Oxidative Stress in Diabetes
Authors: Xie Zhonglin , Zhang Junhua , Wu Jiliang , Viollet Benoit , Zou Ming-Hui
Published: October 2008

OBJECTIVE—Recent evidence suggests that the AMP-activated protein kinase (AMPK) is an important therapeutic target for diabetes. The present study was conducted to determine how AMPK activation suppressed tyrosine nitration of prostacyclin synthase in diabetes.

RESEARCH DESIGN AND METHODS—Confluent human umbilical vein endothelial cells (HUVECs) or mice were treated with 5-amino-4-imidazole carboxamide riboside (AICAR) for the detection of AMPK phosphorylation and the expression of mitochondrial uncoupling protein (UCP)-2.

RESULTS—Exposure of HUVECs to high glucose (30 mmol/l) increased superoxide anions (O2·−) and prostacyclin synthase nitration. In addition, overexpression of constitutively active AMPK (Ad-CA-AMPK) or the addition of AICAR reduced both O2·− and prostacyclin synthase nitration caused by high glucose, whereas adenoviral overexpression of dominant-negative AMPK mutants (Ad-DN-AMPK) enhanced the latter effects of high glucose. Exposure of HUVECs to either AICAR or metformin caused AMPK-dependent upregulation of both UCP-2 mRNA and UCP-2 protein. Furthermore, overexpression of UCP-2 significantly ablated both O2·− and prostacyclin synthase nitration triggered by high glucose. Furthermore, overexpression of Ad-CA-AMPK increased, whereas overexpression of Ad-DN-AMPK inhibited AICAR-induced phosphorylation of p38 kinase at Thr180/Tyr182. Inhibition of p38 kinase with SB239063, which had no effect on AICAR-induced AMPK-Thr172 phosphorylation, dose dependently suppressed AICAR-induced upregulation of UCP-2, suggesting that AMPK lies upstream of p38 kinase. Finally, AICAR markedly increased UCP-2 expression and reduced both O2·− and prostacyclin synthase nitration in diabetic wild-type mice but not in their AMPKα2-deficient counterparts in vivo.

CONCLUSIONS—We conclude that AMPK activation increases UCP-2, resulting in the inhibition of both O2·− and prostacyclin synthase nitration in diabetes.
Plasmacytoid Dendritic Cells Are Proportionally Expanded at Diagnosis of Type 1 Diabetes and Enhance Islet Autoantigen Presentation to T-Cells Through Immune Complex Capture
Authors: Allen Jennifer S. , Pang Karl , Skowera Ania , Ellis Richard , Rackham Chloe , Lozanoska-Ochser Biliana , Tree Timothy , Leslie R. David G. , Tremble Jennifer M. , Dayan Colin M. , Peakman Mark
Published: October 2008

OBJECTIVE—Immune-mediated destruction of β-cells resulting in type 1 diabetes involves activation of proinflammatory, islet autoreactive T-cells, a process under the control of dendritic cells of the innate immune system. We tested the hypothesis that type 1 diabetes development is associated with disturbance of blood dendritic cell subsets that could enhance islet-specific autoimmunity.

RESEARCH DESIGN AND METHODS—We examined blood dendritic cells (plasmacytoid and myeloid) in 40 patients with recent-onset diabetes (median duration 28 days) and matched control subjects. We also examined the relative ability of different dendritic cell subsets to process and present soluble or immune complexed islet cell autoantigen (the islet tyrosine phosphatase IA-2) to responder CD4 T-cells.

RESULTS—The balance of blood dendritic cells was profoundly disturbed at diabetes diagnosis, with a significantly elevated proportion of plasmacytoid and reduction of myeloid cells compared with control subjects. Dendritic cell subset distribution was normal in long-standing disease and in patients with type 2 diabetes. Both dendritic cell subsets processed and presented soluble IA-2 to CD4 T-cells after short-term culture, but only plasmacytoid dendritic cells enhanced (by as much as 100%) autoantigen presentation in the presence of IA-2+ autoantibody patient serum.

CONCLUSIONS—The plasmacytoid subset of dendritic cells is overrepresented in the blood close to diabetes onset and shows a distinctive ability to capture islet autoantigenic immune complexes and enhance autoantigen-driven CD4 T-cell activation. This suggests a synergistic proinflammatory role for plasmacytoid dendritic cells and islet cell autoantibodies in type 1 diabetes.
Weight Gain in Early Life Predicts Risk of Islet Autoimmunity in Children With a First-Degree Relative With Type 1 Diabetes
Authors: Couper Jennifer J. , Beresford Sarah , Hirte Craig , Baghurst Peter A. , Pollard Angie , Tait Brian D. , Harrison Leonard C. , Colman Peter G.
Published: October 2008

OBJECTIVE—In a prospective birth cohort study, we followed infants who had a first-degree relative with type 1 diabetes to investigate the relationship between early growth and infant feeding and the risk of islet autoimmunity.

RESEARCH DESIGN AND METHODS—Infants with a first-degree relative with type 1 diabetes were identified during their mother's pregnancy. Dietary intake was recorded prospectively to determine duration of breast-feeding and age at introduction of cow's milk protein, cereals, meat, fruit, and vegetables. At 6-month reviews, length (or height) and weight, antibodies to insulin, GAD65, the tyrosine phosphatase-like insulinoma antigen, and tissue transglutaminase were measured. Islet autoimmunity was defined as persistent elevation of one or more islet antibodies at consecutive 6-month intervals, including the most recent measure, and was the primary outcome measure.

RESULTS—Follow-up of 548 subjects for 5.7 ± 3.2 years identified 46 children with islet autoimmunity. Weight z score and BMI z score were continuous predictors of risk of islet autoimmunity (adjusted hazard ratios 1.43 [95% CI 1.10–1.84], P = 0.007, and 1.29 [1.01–1.67], P = 0.04, respectively). The risk of islet autoimmunity was greater in subjects with weight z score >0 than in those with weight z score ≤0 over time (2.61 [1.26–5.44], P = 0.01). Weight z score and BMI z score at 2 years and change in weight z score between birth and 2 years, but not dietary intake, also predicted risk of islet autoimmunity.

CONCLUSIONS—Weight gain in early life predicts risk of islet autoimmunity in children with a first-degree relative with type 1 diabetes.
Is the New Mayo Clinic Quadratic Equation Useful for the Estimation of Glomerular Filtration Rate in Type 2 Diabetic Patients?
Authors: Fontseré Néstor , Bonal Jordi , Salinas Isabel , de Arellano Manel Ramírez , Rios Jose , Torres Ferran , Sanmartí Anna , Romero Ramón
Published: October 2008

OBJECTIVE—To test the Mayo Clinic Quadratic (MCQ) equation against isotopic glomerular filtration rate, compared with the Modification of Diet in Renal Disease (MDRD) and the Cockcroft-Gault formulas, in type 2 diabetes.

RESEARCH DESIGN AND METHODS—Based on values obtained with iothalamate, 118 type 2 diabetic patients were divided into three groups according to renal function: hyperfiltration (26), normal function (56), or chronic kidney disease (CKD) stages 3–4 (36). ANOVA, the Bland-Altman procedure, and Lins coefficient (Rc) were performed to study accuracy.

RESULTS—In the hyperfiltration and normal function groups, all prediction equations significantly underestimated the value obtained with isotopic glomerular filtration rate (P < 0.05). In the CKD group, all equations also presented significant differences with the isotopic method. However, MDRD had a bias of −5.3 (Rc 0.452), Cockcroft-Gault formula −0.2 (Rc 0.471), and the MCQ −4.5 (Rc 0.526).

CONCLUSIONS—The MCQ and prediction equations proved inaccurate (excessive underestimation) in type 2 diabetic patients with hyperfiltration or normal renal function. With regard to CKD, the results obtained provided no evidence of superiority of the MCQ over the MDRD or the Cockcroft-Gault formula.
Metabolic Syndrome Predicts New Onset of Chronic Kidney Disease in 5,829 Patients With Type 2 Diabetes
Authors: Luk Andrea O.Y. , So Wing-Yee , Ma Ronald C.W. , Kong Alice P.S. , Ozaki Risa , Ng Vanessa S.W. , Yu Linda W.L. , Lau Winnie W.Y. , Yang Xilin , Chow Francis C.C. , Chan Juliana C.N. , Tong Peter C.Y.
Published: October 2008

OBJECTIVE—Type 2 diabetes is the leading cause of end-stage renal disease worldwide. Aside from hyperglycemia and hypertension, other metabolic factors may determine renal outcome. We examined risk associations of metabolic syndrome with new onset of chronic kidney disease (CKD) in 5,829 Chinese patients with type 2 diabetes enrolled between 1995 and 2005.

RESEARCH DESIGN AND METHODS—Metabolic syndrome was defined by National Cholesterol Education Program Adult Treatment Panel III criteria with the Asian definition of obesity. Estimated glomerular filtration rate (eGFR) was calculated using the abbreviated Modification of Diet in Renal Disease formula modified for the Chinese population. New onset of CKD was defined as eGFR <60 ml/min per 1.73 m2 at the time of censor. Subjects with CKD at baseline were excluded from the analysis.

RESULTS—After a median follow-up duration of 4.6 years (interquartile range: 1.9–7.3 years), 741 patients developed CKD. The multivariable-adjusted hazard ratio (HR) of CKD was 1.31 (95% CI 1.12–1.54, P = 0.001) for subjects with metabolic syndrome compared with those without metabolic syndrome. Relative to subjects with no other components of metabolic syndrome except for diabetes, those with two, three, four, and five metabolic syndrome components had HRs of an increased risk of CKD of 1.15 (0.83–1.60, P = 0.407) 1.32 (0.94–1.86, P = 0.112), 1.64 (1.17–2.32, P = 0.004), and 2.34 (1.54–3.54, P < 0.001), respectively. The metabolic syndrome traits of central obesity, hypertriglyceridemia, hypertension, and low BMI were independent predictors for CKD.

CONCLUSIONS—The presence of metabolic syndrome independently predicts the development of CKD in subjects with type 2 diabetes.
Noninvasive Evaluation of Neural Impairment in Subjects With Impaired Glucose Tolerance
Authors: Putz Zsuzsanna , Tabák Ádám G , Tóth Nelli , Istenes Ildikó , Németh Nóra , Gandhi Rajiv A. , Hermányi Zsolt , Keresztes Katalin , Jermendy György , Tesfaye Solomon , Kempler Péter
Published: October 2008

OBJECTIVE—To evaluate neural dysfunction in subjects with impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS—For this study, 46 subjects with IGT and 45 healthy volunteers underwent detailed neurological assessment. Cardiovascular autonomic function was assessed by standard cardiovascular reflex tests, and heart rate variability was characterized by the triangle index. Sensory nerve function was assessed using Neurometer (for current perception threshold) and Medoc devices. Peak plantar pressure was measured by dynamic pedobarography, and symptoms were graded using the neuropathy total symptom score.

RESULTS—Subjects with IGT had significantly greater abnormalities detected by four of five cardiovascular reflex tests and greater heart rate variability characterized by the triangle index. They had a higher frequency of both hyperesthesia and hypoesthesia as detected by current perception threshold testing at 5 Hz, as well as increased heat detection thresholds.

CONCLUSIONS—This study provides evidence that subclinical neural dysfunction is present in subjects with IGT and can be detected noninvasively. Cardiovascular autonomic neuropathy may contribute to increased cardiovascular risk in IGT subjects.
Application of α and γ Spectrometry in the 210Pb Method to Model Sedimentation in Artificial Retention Reservoir
Authors: Sikorski Jarosław , Bluszcz Andrzej
Published: October 2008

The paper describes the application of the 210Pb method for creating a comprehensive model of sedimentation in the retention reservoir Kozłowa Góra during the 60 years of its use. The model takes into account the temporal and spatial change in the sedimentation conditions. Because of the specific conditions of the young artificial lake, the techniques available to date are not sufficient and it was necessary to modify the 210Pb method. The paper describes such modification of the method and its application to dating the sediments in the reservoir.

For a young lake it is impossible to estimate the activity of authigenic 210Pb with the application of alpha spectrometry because even the oldest sediments contain allochthonous 210Pb. The determination of the activity of authigenic 210Pb in the sediments of the studied reservoir was possible only thank to gamma spectrometry. The gamma ray spectrometry consists of measurements of gamma photons emitted by 210Pb, 214Pb and 214Bi isotopes. Analysis of the 210Pb gamma spectrum line yields information about total activity of 210Pb, while the assessed activity of 214Pb and 214Bi equals to the activity of authigenic 210Pb.
University Presses 2008: A Snapshot in Time
Authors: Bartlett Rebecca Ann
Published: October 2008

As those familiar with Choice know, we devote various issues throughout our volume year to particular themes. For many years the May theme has been ‘university press publishing,’ and over those many years the features that make up this thematic concentration have varied. Always included has been our annual press-by-press list of titles the individual presses themselves deem particularly valuable to undergraduates. Accordingly, following the forum, you will find ‘Significant University Press Titles for Undergraduates, 2007–2008,’ which this year includes entries from a record eighty-four presses.

The other part of the university press feature has been narrative – in recent years a ‘forum’ in which directors of a handful presses offer their thoughts about their particular press or about university press publishing in general. The subtitle of this year's forum (which follows immediately) – ‘From the Prairie to the Pacific Rim’ – reflects the eclectic nature of the contributions: we make no effort to guide the contributors as to content, since we believe that a true pot luck best reflects what is on the tables (to wrest the most out of the food metaphor) of presses of various sizes and from various parts of North America. Every year we seek out new voices, and we hope eventually to hear from most, if not all, university presses in this forum.

Among the new voices we sought out this year was Phil Pochoda's. Director of University of Michigan Press, Phil – like most university press directors – had been thinking a lot about matters digital. When he put his fingers to the keyboard – in response to our invitation – the result was a really meaty feature article that, we believe, deserves a broad audience. Accordingly, you will find herein Phil's piece, ‘The Future of Scholarly Communication: On the Other Side of the Digital Tipping Point.’

As always, we invite reader feedback on these features. E-mail us! Write to us! We welcome your thoughts on these matters or any others related to the work we do at Choice.
On the Author's Addendum
Authors: Thatcher Sanford G.
Published: October 2008

The latest version of the ‘take back the copyrights’ movement within universities in reaction to the so-called serials crisis in scholarly publishing is the recommended adoption of an author's addendum to standard publishing contracts. This article explores the variety of forms this addendum has taken so far and raises questions about its effectiveness in achieving the goals sought. The author's addendum, it is argued, is (1) misleading to the extent that it is based on an incomplete understanding of the causes of journal price inflation; (2) superfluous in recommending reuses that are already allowed under most publishers’ policies; (3) too blunt an instrument for dealing with the many important differences that exist between publishing in the sciences and publishing in the humanities and social sciences; (4) insufficient to protect publishers’ investments to the extent that some versions recommend giving publishers only non-exclusive rights; (5) legally questionable insofar as it relies on an opt-out procedure for publishers’ acceptance; (6) confusing when it relies on unviable distinctions such as commercial versus non-commercial use; (7) troubling to the degree that it fosters an even greater digital divide between book and journal content; and (8) systemically reallocative because it will undermine an important source of revenue for supporting journal and monograph publishing by university presses, complicate the process of negotiating contracts with authors, and thereby increase the financial burden for the universities that currently support presses. This article first appeared in Against the Grain, Vol. 20, No. 3, June 2008; it has been slightly modified to conform to JSP style.
Factors Contributing to Failure of Rotator Cuff Surgery in Persons with Work-Related Injuries
Authors: Razmjou Helen , Lincoln Sandra , Axelrod Terry , Holtby Richard
Published: October 2008

Purpose: Shoulder pain is a major musculoskeletal and economic concern in industrialized countries, with the rate of surgical failure reportedly higher in patients injured at work. The purposes of this study were (1) to examine the prevalence of identifiable causes of rotator cuff surgery failure and (2) to examine the relationship among the existence of these causes and outcome scores, patient expectations, and overall satisfaction.

Methods: This was a cross-sectional study of patients who experienced continued impairments following surgical treatment for work-related injuries. The primary outcome was a disease-specific measure, the Western Ontario Rotator Cuff (WORC) index. Patients were categorized into two groups based on the existence of an identifiable reason for surgical failure vs. no reason for failure, as demonstrated by clinical and radiologic investigations and decided upon by a shoulder surgeon and a physical therapist. Analyses included a t-test for independent sample means, linear regression, non-parametric Wilcoxon test, and Fisher's exact test.

Results: Thirty-eight consecutive patients were included in the study, and 24 causes of surgical failure were identified in 19 patients (50%). Overall, patients with findings of failure were more disabled according to the total WORC index and had higher levels of symptoms, emotional difficulties, and limitations in sports and recreational activities. Expectations and satisfaction levels were not significantly different between groups.

Conclusion: Our results indicate that 50% of patients who reported failed surgery had at least one reason to explain their ongoing symptoms, emotional difficulties, and functional limitations.
Constraint-Induced Movement Therapy for Severe Upper-Extremity Impairment after Stroke in an Outpatient Rehabilitation Setting: A Case Report
Authors: Ploughman Michelle , Shears Jennifer , Hutchings Lisa , Osmond Michelle
Published: October 2008

Purpose: Laboratory studies confirm that constraint-induced movement therapy (CIMT) improves upper-extremity (UE) function after stroke. Due to strict patient criteria and the intensive resources required, CIMT has been slow to become part of rehabilitation practice. Our purpose was to determine the feasibility and effectiveness of an adapted experimental protocol within an outpatient clinical setting for a patient with moderate to severe UE impairment who did not meet traditional CIMT criteria.

Patient Description: AJ, a 16-year-old male, experienced a left middle cerebral artery ischemic stroke due to carotid artery dissection one year before beginning CIMT. He demonstrated some proximal movement but no wrist or finger extension. He had received intensive rehabilitation for 12 months prior to beginning CIMT.

Intervention: Two occupational therapists and two physiotherapists collaborated to provide CIMT task training for 6 hours daily for 2 weeks. A knitted mitten extending to the elbow restrained the less-involved UE during 90% of waking hours. Tasks were tailored to AJ's interests, with the goal of integrating his affected UE into his behavioural repertoire.

Measures and Outcomes: After 2 weeks of CIMT, AJ improved in all measures (grip and lateral pinch strength, Action Research Arm Test [ARAT], and Box and Block Test) except the Chedoke McMaster Impairment Inventory. Greatest gains were seen at 6 months in the ARAT and Box and Block Test, which coincided with patient and family reports of AJ's using his arm in everyday functional tasks.

Implications: Shared workload, emphasis on relevant functional tasks, and complete family participation likely influenced the success of CIMT. Our findings suggest that the strict CIMT criteria used in previous studies may exclude patients who might benefit from the treatment. Controlled trials should be undertaken to examine the effects of CIMT in patients with moderate to severe UE impairment.
Profile of Patients at Admission into an Inpatient Stroke Rehabilitation Programme: Cardiorespiratory Fitness and Functional Characteristics
Authors: Brooks Dina , Tang Ada , Sibley Kathryn M. , McIlroy William E.
Published: October 2008

Purpose: The purposes of this study were to characterize the cardiorespiratory capacity of individuals on admission to inpatient rehabilitation following stroke and to examine the relationship between measures of cardiorespiratory capacity and standard indices of neurological deficit and functional status.

Methods: We recruited 45 patients within the first 10 days of admission to rehabilitation. We performed measures of aerobic fitness (VO2peak), functional status (Functional Independence Measure [FIM] and Clinical Outcomes Variable Score [COVS]), and neurological deficit (National Institutes of Health Stroke Scale [NIHSS] and Chedoke-McMaster Stroke Assessment scale [CMSA]).

Results: Nineteen women and 26 men with a mean (SD) age of 65.2 (14.5) years were admitted to rehabilitation 16.2 (11.9) (minimum 3, maximum 62) days post-stroke. Average VO2peak was less than half the value expected in age-matched healthy individuals at 11.1 (3.1) ml/kg/min. The associations between VO2peak and FIM, NIHSS, and COVS were weak (r = 0.25, -0.12, and 0.26 respectively, p = 0.12, 0.46, and 0.10 respectively). There were no differences in VO2peak in higher-functioning individuals with CMSA leg scores of 5 and 6 compared to lower-functioning individuals with scores of 3 and 4 (p = 0.30).

Conclusion: Cardiorespiratory capacity is extremely low in individuals during the first 3 months after stroke. Alternative measures of functional or clinical status do not adequately reflect this cardiorespiratory state; thus, routine measurement of cardiorespiratory capacity should be considered, along with a risk-factor profile.