bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tuning of the Peng-Robinson Equation of State for Gas Condensate Simulation Studies
Authors: Hosein R. , Dawe R. A. 
Published: June 2012

Abstract
Gas condensate compositional simulation studies are conducted to evaluate gas and condensate reserves. This is carried out when making comparisons of production methods for the economic development of a reservoir. The data needed for the evaluation are dew point pressure, gas compressibility factor, liquid volume and produced gas (Constant Volume Depletion, CVD data) and are nowadays determined from a tuned Equation of State (EOS). However the open literature has shown that there is no consistency in the number of Single Carbon Number (SCN) groups, EOS tuning parameters, lumping schemes and weight factors applied to the experimental when tuning an EOS for use in compositional simulation studies, particularly for gas condensate fluids.
Publications have shown that the two most widely used sets of parameters from the EOS that are tuned are the Binary Interaction Coefficient (BIC) with the critical properties and acentric factor or BIC and the constants called the omegas (Ω’s). The number of SCN groups used for tuning varies from ten to more than forty. However there are currently no criteria for selecting the most reliable lumping scheme that will give similar accuracy to using the many SCN groups except by trial and error or by algorithms designed to test a number of schemes and from which the best one is selected.
In this paper, the Peng-Robinson EOS has been tuned and tested to predict CVD data for seven gas condensate samples. Compositional analysis greater than Single Carbon Number 24 (SCN24) are required for the SCN route. The two sets of tuning parameters were used with and without the VSP. Our parametric study demonstrated that the VSP should not be applied with the Ω’s when tuning the Peng-Robinson EOS. With weight factors of 1 for liquid volume, 10 for gas compressibility factor and without the VSP, the Ω’s give better prediction of CVD data than the critical properties and acentric factor even with the VSP included. The SCN groups for two samples were lumped into six Multiple Carbon Number (MCN) groups using the simple Whitson’s lumping scheme. Our tuning technique with the Ω’s and with our new weight factors for the experimental data, gave differences of less than ±4.0 % from the tuned EOS predictions before and after lumping of the SCN group so that complex algorithms are not necessary to select an appropriate lumping scheme to reduce cost and computer time when performing simulation studies. Our tuning technique with only one regression step, showed consistency in tuning the Peng-Robinson EOS with the Ω’s and could be used for simulation studies of gas condensate systems.
Optimal Gas Utilization for Maximum Recovery in a Mature Oil Field
Authors: Kissoon L. , Persad N. , Marcelle-De Silva J. , Abder C. 
Published: June 2012

Abstract
In this study, a computerized integrated production model was developed for a gas lift system in a mature oilfield located off the east coast of Trinidad. The model included the compressor station, injection manifold, three producing strings, the producing manifold and the low pressure separator, and utilized reservoir pressure-volume-temperature data and injection data. It was used to analyze and provide the optimal allocation of available gas lift gas, over the entire network of wells, using nodal analysis.
Gas lift systems are a well-known form of artificial lift which is used to improve oil production rates. The high-pressure gas injected mixes with the oil column to reduce its density which in return reduces the flowing bottomhole pressure, creating a drawdown large enough for the well to flow. The main operating constraints at this mature field are the fixed amount of gas available for compression to the wells, and the operating pressure of the compressor. Given these constraints, one has to optimally utilize the available lift gas to allow maximum recovery while considering the economics of the project.
The results indicated that using the optimized gas injection rates, an increase in oil production would be realized. An economic evaluation of the optimized system also indicated improved project economics due to a decrease in gas utilization and operational costs.
The work presented in this study is of great value since it was geared towards solving a real industry-based problem. The model which was built can also be used for reservoir management since it is capable of making future predictions. It can also be continuously updated to reflect new operating conditions and changes to the surface piping or the downhole completion. This study shows that integrated asset/production modelling can be quite effective in production optimization.
Multiple Disease Resistance to Four Leaf Spot Diseases in Winter Wheat Accessions from the USDA National Small Grains Collection
Authors: Gurung Suraj , Hansen Jana M. , Bonman J. Michael , Gironella Ann Inez N. , Adhikari Tika B. 
Published: June 2012

ABSTRACTTan spot (TS, caused by Pyrenophora tritici‐repentis), Stagonospora nodorum blotch (SNB, caused by Phaeosphaeria nodorum), spot blotch (SB, caused by Cochliobolus sativus), and Septoria tritici blotch (STB, caused by Mycosphaerella graminicola) are important leaf spot diseases of wheat (Triticum aestivum L. subsp. aestivum) worldwide. Most commercial wheat cultivars are often resistant to one pathogen but susceptible to the others. Our objective was to identify resistance to multiple leaf spot diseases in a subset of winter wheat accessions from the core collection of the National Small Grains Collection of the USDA‐ARS. In total, 633 winter wheat accessions were evaluated for resistance in a greenhouse and 205, 278, 146, and 68 accessions were resistant to TS, SNB, SB, and STB, respectively. Resistance to STB, SNB, and SB were positively associated, but resistance to TS was positively associated only with STB. Except for STB, resistance was more common among accessions from Europe than accessions from Asia. Cultivars and breeding lines were more likely to be resistant to SNB and STB compared with landraces. Fifty‐six accessions were resistant to three or more diseases, and of these, five (CItr16595, PI 278612, PI 351330, PI 361858, and PI 351983) were resistant to all four diseases. On the basis of Germplasm Resources Information Network data, 17 of the 56 wheat accessions were resistant to at least two additional diseases. These multiple disease resistance sources will be useful in wheat breeding programs.
Cross Species Amplification of Pennisetum glaucum Microsatellite Markers in Pennisetum purpureum and Genetic Diversity of Napier Grass Accessions
Authors: Sousa Azevedo Ana Luisa , Costa Pricila Palla , Machado Juarez Campolina , Machado Marco Antonio , Pereira Antônio Vander , José da Silva Lédo Francisco 
Published: June 2012

ABSTRACTNapier grass (Pennisetum purpureum Schum.) is an important forage crop in tropical areas although little is known about its genome information, and few molecular markers have been developed for this species. This work aimed to check the viability of cross‐species amplification of microsatellite markers between pearl millet (Pennisetum glaucum) and Napier grass and to evaluate the genetic diversity among Napier grass germplasm accessions. Fifty‐four microsatellite markers previously described in pearl millet were tested against Napier grass, and 30 markers (55.5%) showed successful cross‐amplification. From them, 18 microsatellite markers were selected to study the genetic diversity in the Embrapa Active Germplasm Bank of Napier Grass (Embrapa‐BAGCE). A total of 180 alleles were identified by these selected microsatellite markers in 107 Napier grass accessions and four pearl millet samples. The average similarity coefficient (Dice) calculated among the Embrapa‐BAGCE accessions was 0.651, ranging from 0.254 to 1.0. Some accessions showed similarity coefficients equal to one, indicating that they have common progenitors or that they might be the same accessions with different denomination. To our knowledge, this work is the first to describe microsatellite markers in Napier grass and represents a significant advance regarding the use of molecular markers in this species.
Determining the Optimum Plant Temperature of Cotton Physiology and Yield to Improve Plant‐Based Irrigation Scheduling
Authors: Conaty W.C. , Burke J. J. , Mahan J. R. , Neilsen J. E. , Sutton B. G. 
Published: June 2012

ABSTRACTA plant‐based thermal optimum approach to irrigation scheduling provides potential benefits in that water applications are scheduled on the basis of plant response to water status. Such irrigation systems require a defined thermal optimum for the crop and while such optimum values have been identified for cotton (Gossypium hirsutum L.) cultivars in the United States, there is no information of this type for cultivars common in Australian production. This paper outlines a threefold approach to determining the optimum temperature (Topt) of the commercial Australian cotton cultivar Sicot 70BRF in an Australian production system. It combines the use of a laboratory‐based fluorescence assay, field‐based net C assimilation rate (A) and stomatal conductance to water vapor (gs), and canopy temperature (Tc)–yield relations. The fluorescence assay showed a Topt between 28 and 30°C while leaf gas exchange rates peaked at a leaf temperature (Tl) of 29°C. The Tc–yield relations peaked at 26°C, with yield reductions observed when Tc > 28°C. We conclude the Topt of the Australian upland cotton cultivar Sicot 70BRF to be 28 ± 2°C. This Topt will provide valuable information for use in thermal optimum irrigation scheduling systems.
Genetic Diversity and Population Structure in a European Collection of Rice
Authors: Courtois Brigitte , Frouin Julien , Greco Raffaella , Bruschi Gianluca , Droc Gaëtan , Hamelin Chantal , Ruiz Manuel , Clément Guy , Evrard Jean‐Charles , van Coppenole Sylvie , Katsantonis Dimitrios , Oliveira Margarida , Negrão Sónia , Matos Celina , Cavigiolo Stefano , Lupotto Elisabetta , Piffanelli Pietro , Ahmadi Nourollah 
Published: June 2012

ABSTRACTIn southern Europe, rice (Oryza sativa L.) is grown as an irrigated crop in river deltas where it plays an important role in the agroecological equilibrium through soil desalinization. In these regions, rice is at the northern limit of its natural area of adaptation. Special cultivars are needed for these challenging conditions. Using model‐based and distance‐based approaches, we analyzed the genetic structure of the European Rice Germplasm Collection (ERGC), which is composed of 425 accessions, using 25 simple sequence repeat (SSR) markers. We compared it with a reference set of 50 accessions that are representative of the diversity of O. sativa. Most of the ERGC accessions (89%) clustered with japonica types. The ERGC japonica accessions were classified into three groups: one group close to rice types of tropical origin that are found in the United States and Argentina and two groups of temperate origin showing less differentiation. The three japonica groups could be characterized according to their grain type and maturity class, which are the most strongly selected traits in European breeding programs. We extracted a core collection of 250 japonica accessions and characterized it using 70 single nucleotide polymorphisms (SNPs). The SSR and SNP dissimilarity matrices coincided reasonably well and for the best‐supported structure, the percentages of admixture were highly correlated. The core collection can be used as an association panel to search for alleles of interest for temperate areas or as a training population for genomic selection.
Identification of Genetic Overlaps for Salt and Drought Tolerance Using Simple Sequence Repeat Markers on an Advanced Backcross Population in Rice
Authors: Yun Wang , Jinping Zang , Yong Sun , Jauhar Ali , Jianlong Xu , Zhikang Li 
Published: June 2012

ABSTRACTSalinity and drought are two of the major abiotic stresses that affect rice (Oryza sativaL.) production especially in Asia. Quantitative trait loci (QTL) for salt tolerance (ST) at seedling stage and drought tolerance (DT) at reproductive stage were identified using 77 BC2F8advanced backcross introgression lines (ILs) derived from a cross of Teqing × Binam in Teqing background. Ten ST QTL were identified governing days to seedlings survival (DSS), score on salt toxicity symptoms on leaves (SST), shoot K+concentration (SKC), and shoot Na+concentration (SNC) at seedling stage, and 23 QTL were identified under reproductive stage drought and irrigated conditions for panicle number per plant (PN), thousand grain weight (TGW), seed fertility (SF), plant height (PH), and grain yield per plant (GYP). Most QTL detected at reproductive stage showed obvious differential expression to drought stress. In addition, another eight QTL were detected by trait ratio of the stress to the irrigation; the alleles at all loci exceptQSf3showed increasing trait values to be associated with Binam, indicating Binam alleles at these loci could improve DT under drought stress. Upon comparison of identified ST and DT QTL we found 14 QTL shared the same genome regions with similar gene actions, clearly suggesting that genetic overlap existed between the two abiotic stress tolerances. Pyramiding of favorable alleles from Binam into Teqing background should allow us to develop superior ILs with higher levels of ST and DT.
Simple Sequence Repeats Linked with Slow Darkening Trait in Pinto Bean Discovered by Single Nucleotide Polymorphism Assay and Whole Genome Sequencing
Authors: Felicetti Erin. , Song Qijian. , Jia Gaofeng. , Cregan Perry. , Bett Kirstin.E. , Miklas Phillip N. 
Published: June 2012

ABSTRACTSeed coat darkening in pinto bean (Phaseolus vulgaris L.) primarily occurs during prolonged storage and can result in significant loss in value based on it being a consumer perceived product flaw. Several slow darkening (SD) pintos, conditioned by the presence of the recessive sd gene, exist but are poorly adapted. Breeding for improved SD pintos is complicated by the recessive inheritance and expression of the trait in maternal tissue. We sought to develop capacity for marker‐assisted selection (MAS) for the SD trait. Three F2 populations (159 individuals) derived from crosses between SD parents, representing two different sources (1533‐15 and SDIP‐1) for the trait, and commercial regular darkening (RD) pintos were used to screen for single nucleotide polymorphisms (SNPs) linked with the sd locus. Separate DNA pools from SD and from RD F2 individuals genotyped for the sd locus were used to detect putative sd‐linked SNPs using the bulked‐segregant analysis strategy. Two of 1536 SNPs differentiated between the SD and RD DNA bulks for all three populations. The whole genome sequence scaffold possessing the two SNPs was canvassed for simple sequence repeats (SSRs). Three of 12 SSRs from the SNP region distinguished between the SD and RD lines. The three SSRs, Pvsd‐1157, Pvsd‐1158, and Pvsd‐0028, were observed to be tightly linked with the sd locus at 0.9, 0.4, and 3.1 cM, respectively, across the F2 populations. The SSRs assayed across a recombinant inbred line mapping population (CDC Pintium × 1533‐15) placed the sd gene on bean linkage group 7 between framework SSR markers BM210 and PvBR35. A survey of SD and RD advanced lines and cultivars revealed the SSRs will have utility for MAS of the SD trait in pinto bean and perhaps in other dry bean market classes as well.
The Evolutionary Origin of Poa annua L.
Authors: Mao Qing , Huff David R. 
Published: June 2012

ABSTRACTPoa annua L. (annual bluegrass) is one of the world's most widely distributed plant species and is ecologically and economically important both as a weed and as a forage and turfgrass. Determining the evolutionary origin of Poa anuua would provide valuable insight into understanding its wide distribution and extreme phenotypic variability. The objective of the present study is to use single copy nuclear DNA sequences trx and CDO504 and chrolopast sequences ndhF and trnTLF to discern the evolutionary origin of Poa annua from all other possible origins. Here we show that the homeologous nuclear DNA sequences present within Poa annua are inseparable from their respective orthologs within Poa supina Schrad. (supina bluegrass) and Poa infirma Kunth (weak bluegrass) and therefore could not have been contributed by any other Poa species. We confirm that Poa infirma served as the maternal parent and provide evidence that at least two interspecific hybridizations gave rise to Poa annua. Our data also suggest that the polyploid origin of Poa annua would be considered recent on an evolutionary time scale. Once the parental species of Poa annua have been identified, we were able to reexamine previously published cytological data and present evidence for the genomic designations of Poa infirma as II and Poa supina as SS, making the genomic constitution of the allotetraploid Poa annua as IISS. The results of this research place new emphasis on chromosomal rearrangements that likely took place during the evolution origin of Poa annua.
Serum 25(OH)D and Type 2 Diabetes Association in a General Population
Authors: Husemoen Lise Lotte N. , Thuesen Betina H. , Fenger Mogens , Jørgensen Torben , Glümer Charlotte , Svensson Jannet , Ovesen Lars , Witte Daniel R. , Linneberg Allan 
Published: June 2012

OBJECTIVE
This study aimed to examine vitamin D status as a determinant for development of type 2 diabetes and deterioration of glucose homeostasis.

RESEARCH DESIGN AND METHODS
A random sample of the general population of Copenhagen, Denmark, was taken as part of the Inter99 study. Included were 6,405 men and women aged 30–65 years at baseline (1999–2001), with 4,296 participating in the follow-up examination 5 years later (2004–2006). Vitamin D was determined at baseline as serum 25-hydroxyvitamin D [25(OH)D]. Diabetes was defined based on an oral glucose tolerance test and a glycosylated hemoglobin (HbA1c) test. Secondary outcomes included continuous markers of glucose homeostasis.

RESULTS
The risk of incident diabetes associated with a 10 nmol/L increase in 25(OH)D was odds ratio (OR) 0.91 (95% CI 0.84–0.97) in crude analyses. The association became statistically nonsignificant after adjustment for confounders, with an OR per 10 nmol/L of 0.94 (0.86–1.03). Low 25(OH)D status was significantly associated with unfavorable longitudinal changes in continuous markers of glucose homeostasis after adjustment for confounders. Fasting and 2-h glucose and insulin as well as the degree of insulin resistance increased significantly more during follow-up among those with low 25(OH)D levels compared with those with higher levels.

CONCLUSIONS
Low 25(OH)D status was not significantly associated with incident diabetes after adjustment for confounders. However, it was significantly associated with unfavorable longitudinal changes in continuous markers of glucose homeostasis, indicating that low vitamin D status could be related to deterioration of glucose homeostasis.
Genetic Risk Score Constructed Using 14 Susceptibility Alleles for Type 2 Diabetes Is Associated With the Early Onset of Diabetes and May Predict the Future Requirement of Insulin Injections Among Japanese Individuals
Authors: Iwata Minoru , Maeda Shiro , Kamura Yutaka , Takano Atsuko , Kato Hiromi , Murakami Shihou , Higuchi Kiyohiro , Takahashi Atsushi , Fujita Hayato , Hara Kazuo , Kadowaki Takashi , Tobe Kazuyuki 
Published: June 2012

OBJECTIVE
We evaluated the clinical usefulness of a genetic risk score (GRS) based on 14 well-established variants for type 2 diabetes.

RESEARCH DESIGN AND METHODS
We analyzed 14 SNPs at HHEX, CDKAL1, CDKN2B, SLC30A8, KCNJ11, IGF2BP2, PPARG, TCF7L2, FTO, KCNQ1, IRS-1, GCKR, UBE2E2, and C2CD4A/B in 1,487 Japanese individuals (724 patients with type 2 diabetes and 763 control subjects). A GRS was calculated according to the number of risk alleles by counting all 14 SNPs (T-GRS) as well as 11 SNPs related to β-cell function (β-GRS) and then assessing the association between each GRS and the clinical features.

RESULTS
Among the 14 SNPs, 4 SNPs were significantly associated with type 2 diabetes in the present Japanese sample (P &lt; 0.0036). The T-GRS was significantly associated with type 2 diabetes (P = 5.9 × 10−21). Among the subjects with type 2 diabetes, the β-GRS was associated with individuals receiving insulin therapy (β = 0.0131, SE = 0.006, P = 0.0431), age at diagnosis (β = −0.608, SE = 0.204, P = 0.0029), fasting serum C-peptide level (β = −0.032, SE = 0.0140, P = 0.022), and C-peptide index (β = −0.031, SE = 0.012, P = 0.0125).

CONCLUSIONS
Our data suggest that the β-GRS is associated with reduced β-cell functions and may be useful for selecting patients who should receive more aggressive β-cell–preserving therapy.
Hemoglobin A1c Versus Oral Glucose Tolerance Test in Postpartum Diabetes Screening
Authors: Picón María José , Murri Mora , Muñoz Araceli , Fernández-García José Carlos , Gomez-Huelgas Ricardo , Tinahones Francisco J. 
Published: June 2012

OBJECTIVE
To determine the usefulness of measuring hemoglobin A1c (A1C), alone or combined with the fasting glucose test, compared with the oral glucose tolerance test (OGTT) for the reassessment of the carbohydrate metabolism status in postpartum women with a history of gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS
We evaluated the status of carbohydrate metabolism by performing the OGTT and fasting glucose and A1C tests in 231 postpartum women with prior GDM 1 year after delivery.

RESULTS
The prevalence of abnormal carbohydrate metabolism was 45.89% by the OGTT criterion, 19.05% by the A1C test criterion, 38.10% by the fasting glucose test criterion, and 46.75% by the A1C-fasting glucose test criteria. Using the OGTT as the gold standard, abnormal carbohydrate metabolism according to the A1C test criterion had 22.64% sensitivity and 54.55% positive predictive value; abnormal carbohydrate metabolism by the fasting glucose criterion had 83.02% sensitivity and 100% positive predictive value. The A1C-fasting glucose test criteria classified 18 women with normal carbohydrate metabolism as having abnormal carbohydrate metabolism. Abnormal carbohydrate metabolism by the A1C-fasting glucose test criteria had 83.02% sensitivity and 81.48% positive predictive value.

CONCLUSIONS
Our results seem to indicate that the A1C test criterion alone or in combination with fasting glucose test criterion does not provide a sensitive and specific diagnosis of abnormal carbohydrate metabolism in women who have had GDM.