bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coordinated Regulation of Heterochromatic Genes inDrosophila melanogasterMales
Authors: Deng Xinxian , Koya S Kiran , Kong Ying , Meller Victoria H 
Published: March 2009

AbstractDosage compensation modifies the chromatin of X-linked genes to assure equivalent expression in sexes with unequal X chromosome dosage. In Drosophila dosage compensation is achieved by increasing expression from the male X chromosome. The ribonucleoprotein dosage compensation complex (DCC) binds hundreds of sites along the X chromosome and modifies chromatin to facilitate transcription. Loss of roX RNA, an essential component of the DCC, reduces expression from X-linked genes. Surprisingly, loss of roX RNA also reduces expression from genes situated in proximal heterochromatin and on the small, heterochromatic fourth chromosome. Mutation of some, but not all, of the genes encoding DCC proteins produces a similar effect. Reduction of roX function suppresses position effect variegation (PEV), revealing functional alteration in heterochromatin. The effects of roX mutations on heterochromatic gene expression and PEV are limited to males. A sex-limited role for the roX RNAs in autosomal gene expression was unexpected. We propose that this reflects a difference in the heterochromatin of males and females, which serves to accommodate the heterochromatic Y chromosome present in the male nucleus. roX transcripts may thus participate in two distinct regulatory systems that have evolved in response to highly differentiated sex chromosomes: compensation of X-linked gene dosage and modulation of heterochromatin.
Repeat Prenatal Corticosteroid Doses Do Not Alter Neonatal Blood Pressure or Myocardial Thickness: Randomized, Controlled Trial
Authors: Mildenhall Lindsay , Battin Malcolm , Bevan Coila , Kuschel Carl , Harding Jane E. 
Published: March 2009

OBJECTIVE. The goal was to determine whether repeat prenatal corticosteroid treatment alters blood pressure and myocardial wall thickness in neonates.METHODS. A randomized, double-blind, placebo-controlled trial was performed in a tertiary perinatal center. Mothers with a singleton, twin, or triplet pregnancy, at a gestational age of &lt;32 weeks, who had received initial treatment with corticosteroid ≥7 days earlier and who were considered to be at continued risk of preterm birth were assigned randomly to receive additional weekly betamethasone or placebo treatment. One hundred forty-five infants born to 120 women were studied. Blood pressure in the first 4 weeks after birth or until hospital discharge and interventricular septal thickness and left ventricular posterior wall thickness in diastole 48 to 72 hours after birth were measured.RESULTS. There were no differences in mean, systolic, or diastolic blood pressures between infants in the placebo and repeat steroid groups. Blood pressures of infants in both groups were similar to published normal values. There were no differences between groups in interventricular septal thickness or left ventricular posterior wall thickness in diastole. In comparison with published normal ranges, however, 24% of infants had interventricular septal thickness and 32% of infants had left ventricular posterior wall thickness of &gt;95th percentile.CONCLUSION. Exposure to repeat prenatal corticosteroid treatment did not increase neonatal blood pressure or myocardial wall thickness in infants who remained at risk of very preterm birth ≥7 days after an initial course of corticosteroid treatment.
Quality-of-Life Concerns Differ Among Patients, Parents, and Medical Providers in Children and Adolescents With Congenital and Acquired Heart Disease
Authors: Marino Bradley S. , Tomlinson Ryan S. , Drotar Dennis , Claybon Emily S. , Aguirre Abigail , Ittenbach Richard , Welkom Josie S. , Helfaer Mark A. , Wernovsky Gil , Shea Judy A. 
Published: March 2009

OBJECTIVES. Mortality rates in pediatric patients with heart disease have decreased dramatically in recent decades, resulting in an increasing number of survivors with morbidities that impact quality of life. The purpose of this study was to assess and compare how heart disease affects the quality of life of the pediatric cardiac patient from the perspectives of the patient, parent, and health care provider.
METHOD. Individual focus groups were conducted with children (8–12 years of age) with heart disease, adolescents (13–18 years of age) with heart disease, parents of children with heart disease, parents of adolescents with heart disease, and health care providers of pediatric patients with heart disease. A structured focus group technique was used to develop a list of potential items that might affect quality of life. Participants chose the 5 most important items from the list. These items were then categorized into preidentified dimensions (physical, psychological, social, school, and other). The percentages of the total votes for all items were calculated and distributions of responses across dimensions within group and within dimension across groups were reported and compared qualitatively.
RESULTS. Patient and parent groups identified similar items as important. Providers identified different items. The physical limitation item received the largest percentage of total votes in all groups (9%–20%). Analysis across dimension revealed that those items related to the physical dimension received the highest percentage of total votes among all groups (30.2%–51.2%). Analysis within dimension revealed that patients endorsed items in the physical dimension more frequently than parents or providers. Within the psychological dimension, the children selected the fewest items relative to all other groups (7.2% vs 21.3%–37.8%), whereas health care providers endorsed these items more frequently than patients or parents (child or parent of child groups 7.2%–21.3% vs health care provider group 28.8%; adolescent or parent of adolescent groups 29.6% vs health care provider group 37.8%). Differences were noted between the child and adolescent groups in the psychological (child versus adolescent: 7.2% vs 29.6%) and school (child versus adolescent: 11.2% vs 2.1%) dimensions.
CONCLUSIONS. Patients and parents generally agreed on how heart disease affects the quality of life of children and adolescents, whereas health care providers had a different opinion.
Aging Effects on Cobalt Availability in Soils
Authors: Wendling Laura A. , Kirby Jason K. , McLaughlin Michael J. 
Published: March 2009

Abstract
Aging processes in soils can significantly affect the potential biological availability of introduced metals via incorporation into crystal lattices, diffusion into micropores, or formation of metal precipitates on the surfaces of soil minerals. Over time, metals in contact with the soil solid phase are less freely exchangeable with the soil solution and, hence, less available to soil biota. In the present study, the effects of aging on the fate and behavior of added divalent cobalt (Co2+) in a range of soils with varying physicochemical characteristics was assessed using isotope-exchange techniques, chemical extraction, and plant growth. Following addition to soil, the Co2+ salt rapidly partitioned to the soil solid phase. Particularly in soils with neutral to alkaline pH, a large percentage of the surface-bound Co was fixed in forms no longer in equilibrium with soil solution cobalt through aging reactions. Using techniques commonly applied to estimate metal bioavailability in soil, the lability (E values), plant availability (L values), and extractability of added Co2+ salts with the mild chemical extractants calcium chloride (CaCl2) and ammonium nitrate (NH4NO3) were observed to markedly decrease with time, particularly in soils with high pH or those containing appreciable quantities of iron/ manganese oxyhydroxide minerals. Results indicated rapid partitioning of added Co2+ into isotopically nonexchangeable pools, with more than 60% of the aging occurring within 15 d in most soils. Soil pH was the primary factor controlling the rate of cobalt aging and extent of exchangeability in the soils examined. Understanding the influence of long-term aging on cobalt availability in soils is necessary to accurately assess the potential risk associated with cobalt contamination of soil environments.
Petrophysical Properties Determination of Tight Gas Sands from NMR Data Using Artificial Neural Network
Authors: Elshafei M. , Hamada G. M. 
Published: March 2009

AbstractAnalysis of heterogeneous gas sand reservoirs is one of the most difficult problems. These reservoirs usually produce from multiple layers with different petrophysical properties. Therefore, using new well logging techniques like NMR or a combination of NMR and conventional open hole logs is essential for improved reservoir characterization. Nuclear magnetic resonance (NMR) logs differ from conventional neutron, density, sonic and resistivity logs because the NMR measurements provide mainly lithology independent detailed porosity and offer a good evaluation of the hydrocarbon potential. NMR logs can also be used to determine formation permeability and capillary pressure.This paper focuses on permeability estimation from NMR logging data. Three models have been used to derive permeability from NMR; Kenyon model, Coates-Timer model and Bulk Gas Magnetic Resonance model. These models have advantages and limitations which depend on the reservoir characteristics. We first estimated permeability from NMR data using the Bulk Gas model. Then neural network model was developed to predict formation permeability using NMR and other open hole logs data. The permeability results of the neural network model and the Bulk Gas model were validated by core permeability for the studied wells.
Organosilicon Drilling Fluid System for HT Deep Gas Wells
Authors: Sun Yuxue , Zhang Yanfen , Zhao Jingyuan 
Published: March 2009

Abstract
Taking temperature as a dividing criterion, the investigations and applications of organosilicon drilling fluid system (ODFS) on the fifth largest gas field in China, Qingshen gas field, have experienced three phases from 180 °C, 200°C to current 220 °C. In the first two phases, ODFS has been successfully used for drilling 48 deep wells.
In the third phase, the high temperature (HT) deep gas well in Qingshen gas field, Xushen22, was drilled to 5320 m (17454 ft) with bottom hole temperature of 220 °C (428 °F). Since high temperature can cause clay dispersion and deactivation, as well as the degradation and crosslink of organic compound, the severe high temperature drilling environment posed a host of technical challenges and environmental issues. The difficulty of drilling operations was further increased by the extremely hard and brittle formation, because such formation potentially increases the risk of hole instability. Therefore, for drilling the HT deep gas well Xushen22, a new type of organosilicon drilling fluid system with improved thermal stability and hole stability was required. Based on the mechanism study on different HT additives, we formulated a high-performance ODFS-III whose properties were examined through a full-scale laboratory tests. Finally, we applied the ODFS-III on well Xushen22.
The results obtained from the field application show that ODFS-III has good thermal stability and special rheology, and also provides good shale stabilization, which meet the hydraulics and hole-cleaning demands of deep-well operations.
Development, Testing, and Field Application of a Heavy Oil Pipeline Cleaning Chemical: A Cradle to Grave Case History
Authors: Wylde Jonathan J. , Slayer Jubal J.L. 
Published: March 2009

Abstract
This paper details the complete evolution of a new cleaning chemical for heavy oil and gas pipelines. Information is offered regarding the reason for development, the research involved in formulation of the new product, as well as the laboratory testing. This paper concludes by giving several case histories of application in cleaning operations in Western United States and Texas.
Oil naturally contains paraffins, asphaltenes and naphthenates. During transport these hydrocarbon components can precipitate and adhere to the pipeline walls and can become associated with iron sulfide scale. Corrosion can often occur on pipeline walls under these organic deposits. Pigging operations are normally performed to remove organic and inorganic debris from the walls of a pipeline. However, these scales can become very compacted and adhere to the walls of the pipeline. It is often necessary to add surfactant based chemicals to assist in the break-up, softening, and transportation of these deposits.
A detailed literature review of the current theory in the chemistry of pipeline cleaning chemicals is presented together with a critical account of the key properties required of these chemistries: wettability alternation, solubilization efficacy of organic materials, emulsification of phases, dispersion, detergency, and defoaming.
An explanation of the laboratory development and evaluation has been given as a preamble for the case histories. One case history details how a pipeline operator unsuccessfully tried to clean a 12″ 9-mile section of pipeline with a pig. The pig was launched and became stuck along the length of the pipeline. Application of the newly developed product was able to free the stuck pig and removed significant debris. By way of conclusion the paper offers suggestions on how chemicals can be most efficiently used in conjunction with these programs.
Estimation of Geothermal Reserves in Oil and Gas Reservoirs
Authors: Zhang Lingyu , Liu Mingsheng , Li Kewen 
Published: March 2009

Abstract
The existing volumetric approach was honored by considering the effects of oil and gas saturations on the evaluation of geothermal resources in oil and gas reservoirs. The main reason to do so was that oil and gas phases may not be simply substituted by water because the values of the specific heat of oil and gas are smaller than that of water. We selected an oil reservoir, Hexaw, from Huabei oil field as an example to apply the method. The effects of oil and gas saturation on the geothermal reserve were investigated at different values of porosity and the results were compared to the existing approaches. It was found that the existing volumetric method tends to overestimate the geothermal reserves in oil and gas reservoirs. The greater the oil or gas saturation is, the more the overestimation of the geothermal reserve is. The results showed that it is necessary to consider the effects of oil and gas saturations on the estimation of geothermal reserve in oil and gas reservoirs.
The Future of California's Oil Supply
Authors: Croft Gregory D. , Patzek Tad W. 
Published: March 2009

Abstract
Once an oil exporter, California now depends on imports for more than 60% of its oil supply. This paper examines the oil production outlook for each of California's major oil sources, including California itself. Oil production trends, published geological and engineering reports, and proposed developments in California's supply area are reviewed to define supply trends, especially for the medium-to-heavy, sour crudes that are processed in California's refineries. Refinery upgrading capacity is already highly developed in California, thus it is assumed that a competitive advantage in heavy, sour crudes will continue, although refining heavy oil releases more carbon dioxide.
About a quarter of California's imports are from Alaska, the rest from foreign sources including Saudi Arabia, Ecuador and Iraq. Before foreign sources became so important, California's refining industry processed California's own crudes and Alaska's North Slope crude. Like those crudes, oil from northern Saudi Arabia, southeast Iraq, and Ecuador is also sour and medium to heavy, ranging from 16 to 35° API and from 2 to more than 3% sulfur by weight. By far the most important sour crude development in California's supply area is Saudi Arabia's 900,000 BOPD Manifa project, originally slated for completion in 2011 but now facing delays. Manifa contains oil that ranges from 26 to 31° API and from 2.8 to 3.7% sulfur. Over the longer term, Alaska will continue to play an important supply role if the Chuckchi and Beaufort Seas live up to expectations.
Middle East production is not increasing, yet oil cargoes from the Middle East have to pass growing Asian markets to reach California. Alaska and Mexico also supply oil to the Pacific Basin, but are facing production declines. The effect of rising Asian demand on Pacific Basin oil markets is already visible, with significant amounts of oil coming to California from Atlantic Basin sources such as Angola, Brazil, and Argentina.
The US West Coast pipeline system is separate from the integrated East Coast, Gulf Coast and Midwest system, so energy security issues for the West Coast may differ from those of the country as a whole. There are policy options that could affect California's oil supply security, including increased oil development in Alaska or offshore California, development of additional oil pipeline outlets on Canada's Pacific Coast or substituting natural gas for oil if possible. All of these policy options are currently the subject of political debate.
Data Processing and Interpretation of Well Test Data as a Nonparametric Regression Problem
Authors: Nomura Masahiko , Horne Roland N. 
Published: March 2009

Abstract
Reservoir pressure has always been the most useful type of data to obtain reservoir parameters, monitor reservoir conditions, and forecast future reservoir performances. This work investigates a nonparametric method to analyze well test and production data. We address both data processing and parameter estimation problems from a data smoothing aspect. The procedure enables us to develop an insight into the specific issues: (1) model recognition, (2) flow rate estimation, and (3) transient identification. We demonstrate the procedures on synthetic and actual field examples.
Dimensionless Characterization of Transient Pressure Volume Behaviour for Foamy Oils
Authors: Huerta M. , Andarcia L. , Jossy E. 
Published: March 2009

Abstract
Foamy oils are generated during the depressurization of heavy oils that contain dissolved gases. Foamy oil behaviour seems to play an important role in cold production, so the understanding of transient pressure-volume expansion behaviour of foamy oils is very important. Results of various mercury withdrawal experiments obtained at different flow rates and oil viscosities in a sand pack filled with heavy oil saturated with methane are analyzed in this work using a dimensionless characterization approach. A series of experiments with a varying fluid flow rate and a range of fluid viscosities were used. Different scaling groups based on capillary number and two different mathematical expressions that involve the initial pressure depletion rate were constructed. The initial depletion rate to the point of maximum supersaturation was used, as well as properties such as diffusion coefficient, interfacial tension, and viscosity. In the dimensionless analysis shown in this work, only the first stages of bubble nucleation and growth exhibited in the range of Sg = 0% to Sg = 8% were used. The pressure at the maximum supersaturation fits well with all dimensionless numbers tried in this work. Typically, when the experimental results were re-plotted using the dimensionless variables, the data lie mainly on a straight line. Only the experimental tests with the highest fluid rate and highest viscosity did not follow this trend. The best correlation was obtained with the dimensionless number that involved a diffusion coefficient. These preliminary results suggest that there exists a strong relationship between the foamy oil behaviour observed during gas exsolution experiments and capillary forces/diffusive mass transfer phenomena in the presence of high depletion rates. Lower diffusive mass transfer of the dissolved gas together with high interfacial tension could result in the formation of smaller gas bubbles sustained for a longer time. The discovery of the mathematical relationship shown in this work between foamy oil behaviour and a dimensionless number involving capillary forces/diffusive mass transfer, may provide the basis to forecast the range of variables at which foamy oil behaviour might be observed.
Prudhoe Bay: Rebuilding a Giant Oil and Gas Full Field Model
Authors: Ding Eric , Harrison Peter , Dozzo Joe , Lin C. Y. 
Published: March 2009

Abstract
The Prudhoe Bay field is the largest accumulation of oil and gas in North America. Because of the size, and the fact that it produces from multiple mechanisms including lean gas cycling, gravity drainage, pattern waterfloods, pattern MI / WAG injection and gas cap water injection for pressure maintenance, a full-field model (FFM) with a rigorous surface pipeline network and facilities model is necessary to answer many depletion planning questions and to evaluate the benefits of large-scale or field-wide projects. With additional reservoir description data and production history, the opportunity existed to use current software and hardware to build an improved model. In 2005 an effort began to build a new FFM, including both geocellular and simulation models. This paper discusses the issues addressed at the start of the rebuild in preparation for the history match, the history matching effort, and the transition to predictive runs.
Preparation for the history match included setting the objectives for the model, the grid design, generating pseudo relative permeability curves, and implementing parallel processing. The key parameters and data used to obtain a history match are discussed, as are the issues and methodology utilized in constructing predictive cases. Some of the key interactions with the parallel geologic model construction are also discussed.
It was demonstrated that a compositional model with approximately 1 million active cells and over 650,000 non-neighbor connections associated with over 1000 structural faults could be run and history matched in a commercial parallel reservoir simulator in a reasonable time.
With approximately 25 BSTB of oil, 46 TSCF of gas in place, and over 2500 historical wells, the challenge of building a full-field model for a field the size of Prudhoe Bay was daunting. A project of this magnitude required excellent up-front preparation and cross-discipline coordination.