bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grade and laterality of intraventricular haemorrhage to predict 18–22 month neurodevelopmental outcomes in extremely low birthweight infants
Authors: Merhar Stephanie L , Tabangin Meredith E , Meinzen‐Derr Jareen , Schibler Kurt R 
Published: December 2011

AbstractAim:  To determine whether extremely low‐birthweight (ELBW) infants with bilateral compared to unilateral intraventricular haemorrhage (IVH) have worse neurodevelopmental outcomes at 18–22 months.Methods:  A total of 166 ELBW infants (<1000 g) admitted to a Cincinnati NICU from 1998 to 2005 with a head ultrasound showing Grade I–IV IVH and neurodevelopmental assessment at 18–22 months corrected age were included. Multivariable linear and logistic regression models were developed to determine the impact of laterality and grade of IVH and other clinical variables to predict scores on the Bayley Scales of Infant Development, Second Edition, Mental Development Index and Psychomotor Development Index and the combined outcome of neurodevelopmental impairment (NDI).Results:  Infants with bilateral grade IV IVH had lower adjusted mean Bayley scores compared with infants with unilateral grade IV IVH. For grades I, II and III IVH, bilaterality of IVH was not associated with lower mean Bayley scores. Infants with grade IV IVH had the highest odds of NDI. The probability of NDI increased with sepsis and postnatal steroid use.Conclusion:  ELBW infants with bilateral compared to those with unilateral grade IV IVH had worse neurodevelopmental outcomes. Infants with grades I–III IVH had similar outcomes whether they had unilateral or bilateral IVH.
The promoter of filamentation (POF1) protein from Saccharomyces cerevisiae is an ATPase involved in the protein quality control process
Authors: Costa Iris M , Nasser Tallybia HT , Demasi Marilene , Nascimento Rafaella MP , Netto Luis ES , Miyamoto Sayuri , Prado Fernanda M , Monteiro Gisele 
Published: December 2011

Abstract

Background
The gene YCL047C, which has been renamed promoter of filamentation gene (POF1), has recently been described as a cell component involved in yeast filamentous growth. The objective of this work is to understand the molecular and biological function of this gene.

Results
Here, we report that the protein encoded by the POF1 gene, Pof1p, is an ATPase that may be part of the Saccharomyces cerevisiae protein quality control pathway. According to the results, Δpof1 cells showed increased sensitivity to hydrogen peroxide, tert-butyl hydroperoxide, heat shock and protein unfolding agents, such as dithiothreitol and tunicamycin. Besides, the overexpression of POF1 suppressed the sensitivity of Δpct1, a strain that lacks a gene that encodes a phosphocholine cytidylyltransferase, to heat shock. In vitro analysis showed, however, that the purified Pof1p enzyme had no cytidylyltransferase activity but does have ATPase activity, with catalytic efficiency comparable to other ATPases involved in endoplasmic reticulum-associated degradation of proteins (ERAD). Supporting these findings, co-immunoprecipitation experiments showed a physical interaction between Pof1p and Ubc7p (an ubiquitin conjugating enzyme) in vivo.

Conclusions
Taken together, the results strongly suggest that the biological function of Pof1p is related to the regulation of protein degradation.
Association study between the gibberellic acid insensitive gene and leaf length in a Lolium perenne L. synthetic variety
Authors: Auzanneau Jérôme , Huyghe Christian , Escobar-Gutiérrez Abraham J , Julier Bernadette , Gastal François , Barre Philippe 
Published: December 2011

Abstract

Background
Association studies are of great interest to identify genes explaining trait variation since they deal with more than just a few alleles like classical QTL analyses. They are usually performed using collections representing a wide range of variability but which could present a genetic substructure. The aim of this paper is to demonstrate that association studies can be performed using synthetic varieties obtained after several panmictic generations. This demonstration is based on an example of association between the gibberellic acid insensitive gene (GAI) polymorphism and leaf length polymorphism in 'Herbie', a synthetic variety of perennial ryegrass.

Methods
Leaf growth parameters, consisted of leaf length, maximum leaf elongation rate (LERmax) and leaf elongation duration (LED), were evaluated in spring and autumn on 216 plants of Herbie with three replicates. For each plant, a sequence of 370 bp in GAI was analysed for polymorphism.

Results
Genetic effect was highly significant for all traits. Broad sense heritabilities were higher for leaf length and LERmax with about 0.7 in each period and 0.5 considering both periods than for LED with about 0.4 in each period and 0.3 considering both periods. GAI was highly polymorphic with an average of 12 bp between two consecutive SNPs and 39 haplotypes in which 9 were more frequent. Linkage disequilibrium declined rapidly with distance with r 2 values lower than 0.2 beyond 150 bp. Sequence polymorphism of GAI explained 8-14% of leaf growth parameter variation. A single SNP explained 4% of the phenotypic variance of leaf length in both periods which represents a difference of 33 mm on an average of 300 mm.

Conclusions
Synthetic varieties in which linkage disequilibrium declines rapidly with distance are suitable for association studies using the "candidate gene" approach. GAI polymorphism was found to be associated with leaf length polymorphism which was more correlated to LERmax than to LED in Herbie. It is a good candidate to explain leaf length variation in other plant material.
Distribution of Coronary Artery Stenosis After Radiation for Breast Cancer
Authors: Nilsson Greger , Holmberg Lars , Garmo Hans , Duvernoy Olov , Sjögren Iwar , Lagerqvist Bo , Blomqvist Carl 
Published: December 2011

Purpose To study distribution of coronary artery stenosis among patients with breast cancer (BC) and to assess correlation between radiotherapy (RT) and location of stenosis. Patients and Methods A Swedish BC cohort diagnosed from 1970 to 2003 was linked to registers of coronary angiography from 1990 to 2004, which yielded 199 patients. Stenoses of the coronary arteries were graded from 0 to 5, where 0 indicated a normal vessel and 5 indicated occlusion. Two hotspot areas for radiation were defined: proximal right coronary artery (prox RCA), mid and distal left anterior descending artery and distal diagonal (mdLAD + dD). RT regimens were categorized as high or low risk of irradiating the hotspot areas. Left breast/chest wall was considered high risk for mdLAD + dD; left internal mammary chain (IMC), high risk for prox RCA and mdLAD + dD from 1970 to 1995 and thereafter solely for mdLAD + dD; and right IMC, high risk for prox RCA. Other RT targets and no RT were considered low risk. Results were expressed in odds ratios (ORs) and 95% CIs. Results For irradiated left- versus right-sided BC, the OR for grade 3 to 5 stenosis in mdLAD + dD was 4.38 (95% CI, 1.64 to 11.7), and for grade 4 to 5 stenosis, the OR was 7.22 (95% CI, 1.64 to 31.8). For high-risk RT versus low-risk or no RT, the OR for grade 3 to 5 stenosis in hotspot areas was 1.90 (95% CI, 1.11 to 3.24). Conclusion An increase of stenosis in mdLAD + dD in irradiated left-sided BC and an association between high-risk RT and stenosis in hotspot areas for radiation indicate a direct link between radiation and location of coronary stenoses.
Alternative Shut-In and Pump Start-Up Procedures for Kicks Taken During MPD Operations
Authors: Chirinos J. E. , Smith J. R. , Bourgoyne D. A. 
Published: December 2011

Abstract
A university-industry consortium has been studying alternative well control procedures for kicks taken during managed pressure drilling (MPD) operations using the constant bottom hole pressure (CBHP) method. This paper explains and evaluates the specific shut in and pump start up procedures resulting from that study.
Shutting in the blowout preventer (BOP) is the standard reaction to a kick taken during conventional drilling. Shut in has been concluded to be the appropriate response for kicks during MPD in some circumstances. Two different shut in procedures are applicable: a simple shut in and a MPD pump shut down with a "choked flow check." Both require a pump start up schedule to begin circulating out a kick.
A simple procedure for defining a pump start up schedule and its basis are described. Shut in and application of the pump start up schedule for circulating out a kick were simulated for a wide range of well and kick conditions. This method stopped formation flow and kept bottom hole pressure relatively constant during pump start up and kick circulation for the full range of scenarios studied. The realism of simulation results was confirmed by comparison to a full scale gas kick experiment.
A manual MPD pump shut down with a "choked flow check" was also performed in both the simulator and the experimental well. The procedure, which allows a flow check without letting bottomhole pressure drop significantly below the intended pressure, is explained. It was shown to be effective for detecting or confirming low rate kicks that cannot be detected conclusively during circulation.
The Added Value of Piloting Maximum Reservoir Contact Wells Prior to Large Scale Application to a Giant Offshore Carbonate Field
Authors: Al Marzouqi Mohamed , Khedr Osama , Martin Wallace William , Brantferger Kenneth , Walters John Victor , Jackson Alfred 
Published: December 2011

Abstract
This paper presents a success story covering the design, execution and post job evaluation of drilling and completing two Maximum Reservoir Contact (MRC) pilot wells. The wells were drilled and tested as part of a pilot wells programme aimed at proving-up to the well architectures planned to be introduced on a field wide basis.
The carbonate field lies offshore Abu Dhabi in relatively shallow waters. Prior studies have confirmed the viability of continuing development of the field from artificial islands (drilling and production centers) by utilizing Extended Reach Drilling (ERD) and MRC well technology. The effectiveness of the MRC wells is critically dependent on well planning, design and placement in the reservoir interval. The paper describes the integrated workflow and well optimization process that have been applied to the two pilots which cover the following steps:Model developmentSimulation for completion options screeningProduction prediction by coupled reservoir-well dynamic simulationFlow assuranceAssessment of coiled tubing and wireline accessibilityDrilling and completions engineering analysis, time, cost and risk assessment.
The application of this process has led to a number of (local) well records, firsts and learning’s that can be applied to future wells. The paper also summarizes the post drilling evaluation activities, which included running of production logging tools to optimize acid stimulation, an extensive flow test and data gathering program, and well model construction and validation to closely monitor and assess well performance.
Evaluation and Application of the Extended Cyclic Steam Injection as a New Concept for Bachaquero-01 Reservoir in West Venezuela.
Authors: Chourio Geragg , Bracho Jose , Mohtadi Mehrdad 
Published: December 2011

Abstract
The thermal recovery method has been applied in to the heavy oil reservoirs in Venezuela for more than 50 years. The cyclic steam injection is the principal thermal technique in Venezuelan heavy oil reservoirs, which has an oil viscosity at reservoir conditions between 600 to 5000 cp. Steam flood has been applied in Venezuela as a pilot project in the Tia Juana reservoir (Formation C3-C4 and M-6) and East Venezuela in the Oficina Formation.
The Bachaquero-01 heavy oil reservoir has been producing with cyclic steam injection since 1965. Due to the high number of steam cycles (more than 6 steam cycles per well), cyclic steam injection is not economical in a lot of wells. Therefore an extensive work has been done to improve the economics of steam injection in Bachaquero-01 reservoir.
In this paper we present the application and the results of the extended cyclic steam injection, which is a combination of cyclic steam injection and continues steam injection. For the evaluation of this thermal process for Bachaquero-01 reservoir, we used an available history matched full field thermal model of the Bachaquero-01 (Area 95 Km², OOIP 6621 MMSTB, Recoverable Reserves 1072 MMSTB, Number of perforated wells 776, number of steam cycles 1600). Within the Bachaquero-01 reservoir we defined a representative area with 7 inverted seven-spot patterns. We discuss the results of the application of the extended cyclic steam injection and make a comparison with the results of the traditional steam flood and conventional cyclic steam injection. The field application of the extended cyclic steam injection for the Bachaquero-01 reservoir has been approved by the PDVSA management. The field site has been selected and the project will start at the beginning of 2012.
Advanced Reservoir Management of Greater Burgan Field
Authors: Su HoJeen , Ali Farida M. , Orjuela Jaime A. , Gheorghiu Sorin 
Published: December 2011

Abstract
The Greater Burgan field is the largest sandstone reservoir system in the world, and its complexity requires the state of art technology for a sound reservoir management practice. This paper will discuss our methodology to maximize the production plateau length of Burgan field using parallel reservoir simulation, waterflood efficiency algorithm, streamline visualization, and ensemble-based optimization method.
With a reservoir dimension longer than 48 km, parallel reservoir simulation becomes necessary for an integrated Burgan field study. Through history matching of 60-year production data, we quantified billions of barrels vertical fluid migration between major reservoir units, and fluid migration is a major concern in making reservoir management decisions. To optimize future development plans, an economic analysis package was developed to evaluate various operating scenarios, and Net Present Value (NPV) is used as an objective function. The scalability data of parallel reservoir simulation are discussed.
The waterflood efficiency algorithm was based in injection efficiency or remaining oil recovery, and the input could come from finite-difference simulation, streamline simulation, and field surveillance data. The algorithm utilized the injector-producer connectivity relationship realized from streamline analysis, and it calculated the amount of water injection for each injector in order to achieve maximum sweep efficiency.
The alternative method to optimize the waterflood is based on the ensemble method in which hundreds of simulation models with different operating settings are automatically submitted to run. Results of all models are gathered and analyzed by co-variance. A better setting will be proposed for each model and the next batch of simulation is then launched. At the end, all models will converge to an optimized operating setting.
Maximizing Tight Gas Recovery through a New Hydraulic Fracture Optimization Model
Authors: Rahman M. M. , Sarma H. K. 
Published: December 2011

Abstract
As the demand for gas increases worldwide, tight and deep unconventional gas reservoirs are becoming the target for development. However, for such reservoirs the conventional approach of simply fracturing the formation in such reservoirs to hydraulically stimulate the well is inadequate. This is because most currently available commercial software lack proper optimization tools in them and they do not take into consideration several key parameters and realistic constraints in them.
An integrated but constrained model to optimize hydraulic fracture treatment has been developed to maximize gas production and net present value with minimum treatment cost. A dual objective function has been incorporated to satisfy operator's economic constraints and also to investigate trade-off between two conflicting design objectives. Model couples both the industry experience and design constraints based on hydraulic fracture mechanics. The global optimization scheme in the model is driven by an intelligent moving-object algorithm. Unlike commercial software, important design parameters are included as the free design variables which are randomly varied during optimization. Model has been successfully applied to a hypothetical deeper tight gas formation to demonstrate its merits. The optimum treatment design indicates a significant incremental production (by 300% compared to production from non-fractured tight gas well) at lower cost compared to production from non-fractured tight gas sand. Insightful parametric sensitivity analyses are also presented. This model could also be used to study the potential of the deep UAE gas sands.
The Practical Applications Of Coupled Models From Reservoir To Sales Point For Fields With Highly Variable CO2 Content
Authors: Ong Cheng-Sun , Maroongroge Vichai , Tan Leong Hooi , Chin Yee Hoe 
Published: December 2011

Abstract
This paper presents an integrated production model construction workflow with actual field application from four fields with multiple stacked reservoirs and with varying carbon dioxide (CO2) content (up to 60%) located in the Malaysia-Thailand Joint Development Area (MTJDA). The subsurface-to-surface linked coupled models are history matched to field performance and reconciled to the surface gas utilization (fuel, flare, drop-out, etc.) under specific operating conditions to meet sales specifications. The capability of the subsurface-to-surface linked coupled models is further enhanced with the modeling of the CO2 membrane unit to aid in development planning. This integration is expected to help to maximize the economic value from the assets by accurately predicting the reservoir performance with respect to the surface network constraints.
The objectives of this project are to: Produce more reliable sales forecastsGenerate representative reserves recovery estimatesEqually compare different projects in different fieldsEstimate the timing of future developments to meet existing Gas Sales Agreements
The construction workflow can be described in four steps: Project DefinitionTest of ConceptQuality ControlForecast.
Project work scope calls for a coupled model that is able to generate a fully-automated combined field deliverability forecast at specified sales CO2 content that takes into account the CO2 removal unit, intra-field pipeline network, and every developable reservoir within the area.
This custom built simulation model is capable of generating incremental production profiles from the integrated dynamic simulation models (as opposed to tank models) to the sales point and its configuration allows a "plug and play" option to allow additional models to be integrated easily. This is an example of effective use of current simulation techniques to robustly and efficiently address the challenges of developing complex assets with highly variable CO2 content.
Geomechanics and Fluid Flow Modeling Using Finite-Difference Method
Authors: Albinali Ali A. , Kazemi Hossein , Alghamdi Bander N. 
Published: December 2011

Abstract
When hydrocarbon reservoirs undergo pressure depletion during production or pressure increase during fluid injection, the reservoir rock frame, as well as the rock mass above and below the reservoir, undergoes anisotropic stress changes. In most existing subsurface simulators, the change in rock stress is accounted for only via rock and fluid compressibilities; however, for more accurate fluid flow and rock mechanics modeling, a coupled geomechanics and fluid flow subsurface simulateor should be used. The work presented in this paper investigated developing a mathematical formulation using finite-difference techniques to solve the geomechanics' equations consistent with the mathematical formulation for solving fluid flow equations. The key considerations are consistency of the mathematical formulation (finite-difference technique) for both geomechanics and fluid flow calculations, and ease of implementing this formulation. The results show that it has successfully modeled the induced stress changes in the reservoir rock created by either fluid production or injection. In addition, the solution obtained from applying finite-difference technique in solving the geomechanics equations are comparable to that obtained from using finite-element techniques. Furthermore, the experience obtained from this work indicates that the adapted control volumes for fluid flow and geomechanics computations are well-structured and the developed formulation is computationally robust.
Modified EOR Screening Criteria as Applied to a Group of Offshore Carbonate Oil Reservoirs
Authors: Bourdarot Gilles , Ghedan Shawket 
Published: December 2011

Abstract
This screening study has been applied on a group of offshore carbonate oil reservoirs. The methodology is based on the EOR screening criteria set forth by Taber et. al.1,2 enriched with additional screening criteria. The EOR techniques screened included solvent flooding (miscible, immiscible hydrocarbon and CO2 Gas flooding), chemical flooding (Polymer flooding, and Surfactant and Polymer flooding), as well as Thermal flooding (Steam injection and In-situ combustion) techniques. The screening study investigated the challenging and the killing parameters of each technique if any, indicating the most applicable EOR technique.
By comparing the depth and API gravity data of the reservoirs under study to that of the worldwide producing EOR projects, it was possible to define at a glance which EOR methods have been already experienced for the same conditions of reservoir depth and API oil gravities. Furthermore, by considering the relatively high pressure and temperature of the heterogeneous carbonate reservoirs under study, with its low viscosity oil, and the associated high salinity formation water, several EOR methods can be discarded including: Steam Injection, In Situ Combustion, and Polymers.
Two methods were found to be most suitable for most of the reservoirs: Miscible Hydrocarbon and CO2 Gas injection. Minimum Miscibility Pressure (MMP) has been estimated using correlations. A miscible gas injection could be achieved in most of the reservoirs by adding 2 to 13% C3-C4 to processed gas. CO2 mimimum miscibility pressure, MMP, is expected to be about 1000 psi lower than most of the reservoir pressures, making CO2 miscible flooding to be easily achieved.
Surfactant Polymers flooding could reduce Remaining Oil Saturation in reservoirs with more than 50mD permeability. This technology is less mature, than other EOR technologies. It is yet too challenging due to the high salinity, high temperature and carbonate formation.