bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permanent Production Packer Installations in Canadian Gas Wells
Authors: Welsh G.A. 
Published: August 2010

ABSTRACT
Permanent production packer installations have been widely used in Canadiangas wells. They also have been used, but to a lesser degree, in oil and waterwells. A permanent production packer virtually becomes a part of the casing andprovides a sound, reliable base on which a successful well completion may bebuilt. Although many types of installations have been used successfully, thispaper will describe only those most commonly used. As tubing movement must be amajor consideration in the design of permanent packer installations, this paperwill also discuss causes, effects and calculations for such movement.

INTRODUCTION
PERMANENT TYPE PRODUCTION PACKERS have proved to be efficient and reliabletools for segregating fluids and pressures in Canadian gas wells. Most suchinstallations have been in wells that are particularly hot, high pressure orcorrosive, and in wells where more than one of these extreme conditionsexist.
Due in part to this variety of conditions -along with fluid, pressure andtemperature changes encountered during well treatment, and well owners'individual preferences -several different basic packer installations haveevolved.
As most of these installations have proved highly successful, it appearsuseful to describe in detail those most commonly used. To this end, differentpermanent packers and allied equipment will be shown and discussed.
This will be followed by diagrams and explanations of the nine most commonbasic installations. As a major consideration in almost all of these gasinstallations has been tubing movement, the causes, effects and calculationsfor same will be described. For the most part, all discussion will be confinedto installations in wells with a single gas zone. With the exception ofreference to hot oil and fluid injection strings, discussion will center onwells with single tubing strings.

PERMANENT PACKERS AND ALLIED EQUIPMENT
Permanent production packers may be set on either wire line or tubing. Ontubing, this may be achieved by mechanical or hydraulic means. Most packers areset on wire line for greater accuracy and speed and to minimize the possibilityof accidental presetting. Such packers fall into two categories top sealing andthrough sealing. Top Sealing packers provide a larger minimum bore (I.D.) forproduction or injection (Figure 1a).
Through Sealing packers allow for the addition of tailpipe to theseals on the tubing string. Also, on some through sealing installations, additional seal units maybe attached and the tubing allowed to travel. Thisminimizes or eliminates the possibility of parting at the surface (Figure1b).
Also available are permanent production packers with packer body extensionson the bottom, on which maybe be installed tailpipe or other equipment, or withpacker bore extensions on the bottom which provide additional sealing borelength and external protection to the seals from corrosive well fluids (Figures2a and 2b.
Association Mapping of Malting Quality Data from Western Canadian Two‐row Barley Cooperative Trials
Authors: Beattie Aaron D. , Edney Michael J. , Scoles Graham J. , Rossnagel Brian G. 
Published: August 2010

ABSTRACTRe‐examining historical datasets is a proposed use for association mapping (AM) and is particularly valuable when the data describes time‐consuming and/or expensive to measure traits. A collection of 91 elite two‐row malting barley (Hordeum vulgare L.) lines entered in the western Canadian Cooperative Two‐Row Barley Trials over a 13‐ yr period were analyzed by AM to identify markers associated with seven malting quality traits. A linear mixed‐model incorporating population structure and familial relatedness identified 27 diversity array technology (DArT) markers associated with malting quality. These markers will assist selection of parents with complementary allele combinations for future crosses and help identify progeny with the desired alleles. Putative candidate expressed sequence tags (ESTs) responsible for marker‐trait associations were identified for 19 of the 27 DArT markers and include genes important for seed storage protein accumulation, gibberellin‐mediated gene expression, seed storage mobilization, and dormancy. Efforts to identify novel variability in these genes may present opportunities to improve malting quality.
Development of a Multiplex Polymerase Chain Reaction Method for Simultaneous Detection of Four Cimicifuga Species
Authors: Jigden Baigalmaa , Wang Hongtao , Kim Yeon‐Ju , Noh Jong‐Hun , Gotov Choijamts , Lee Jong‐Il , Yang Deok‐Chun 
Published: August 2010

ABSTRACTExpensive herbs like oriental medicinal plants are always possible targets for fraudulent labeling or misuse in many countries. In the genus Cimicifuga, most species have been used as “Sheng‐Ma” for oriental medicinal purposes. Among the Cimicifuga species, C. heracleifolia Kom., C. dahurica (Turcz. ex Fisch and C.A. Mey.) Maxim., C. foetida L., and C. simplex (DC.) Wormsk. ex Turcz. were used as certified medicinal materials in Korea, China, and Japan. To identify these four Cimicifuga species, the internal transcribed spacer was used for polymerase chain reaction (PCR) analysis, and nucleotide polymorphisms were identified in the four Cimicifuga species. Four specific primers were designed from their polymorphic sites to identify Cimicifuga species using multiplex PCR. The established multiplex‐PCR proved to be effective for the differentiation of Cimicifuga species in commercial materials.
Root Distribution of Temperate Forage Species Subjected to Water and Nitrogen Stress
Authors: Skinner R. Howard , Comas Louise H. 
Published: August 2010

ABSTRACTRoot allocation and distribution patterns can influence forage yield during periods of moisture or nitrogen stress, as deep‐rooted species access water and nutrients found deeper in the soil profile. In a greenhouse study, we examined rooting characteristics to a depth of 50 cm for 21 cool‐season forage species (9 grasses, 6 legumes, and 6 forbs) exposed to drought and low N conditions. The goal of this research was to compare root distribution under uniform growing conditions for common grass, legume and non‐leguminous forb species found in humid‐temperate pastures of the northeast United States. Nitrogen or water stressed grasses generally had greater root biomass and a greater proportion of roots in the 30 to 40 cm soil layer than did stressed legumes or forbs. Low N significantly reduced root weight, but to a lesser extent than the decrease in shoot weight, resulting in an increase in root/shoot ratio. Drought stress reduced shoot weight but had no effect on root weight, also resulting in a greater root/shoot ratio. Drought stress also increased the proportion of deep roots compared with controls, whereas, N stress did not. Comparisons with previously published field studies suggested that information from container‐grown plants could provide insights into field results, and also suggested that inherent species differences in root distribution could explain some, but not all, rooting patterns observed in multi‐species forage mixtures.
Proper Management Improves Seedling Survival and Growth during Early Flooding in Contrasting Rice Genotypes
Authors: Ella Evangelina S. , Dionisio‐Sese Maribel L. , Ismail Abdelbagi M. 
Published: August 2010

ABSTRACTFlooding following direct seeding reduces germination and emergence in rice (Oryza sativa L.); however, crop establishment can be enhanced through genetic improvement and proper management. This study describes the effects of selected management practices on seedling survival of rice genotypes that vary in tolerance of flooding during germination. Seeds were sown in pots and submerged, and seedling survival was determined 21 d later. Extent of lipid peroxidation and activity of reactive oxygen‐scavenging enzymes in dry seeds and amylase activity in germinating seeds were assessed. Flooding decreased survival in old seeds and in seeds stored at warmer temperature, and this reduction was associated with a decrease in activities of superoxide dismutase and catalase and an increase in lipid peroxidation. Survival, shoot and root growth, and activities of amylase enzymes measured 3 d after sowing were highest when floodwater temperature was 24 to 26°C. Survival decreased with increasing water depth and algal growth and correlated positively with total amylase activity and negatively with lipid peroxidation. Apparently, floodwater conditions and seed handling affects survival in direct‐seeded rice subject to early flooding, and tolerant genotypes are more responsive to such conditions. Sowing properly stored, fresh seeds in a well‐prepared seedbed to control flooding depth and irrigating with water at optimum temperature will further enhance the establishment of tolerant genotypes.
Determining Salinity Threshold Level for Castor Bean Emergence and Stand Establishment
Authors: Zhou Guisheng , Ma B. L. , Li Jun , Feng Chaonian , Lu Jianfei , Qin Pei 
Published: August 2010

ABSTRACTCastor bean (Ricinus communis L.) is grown on marginal lands that can be prone to having medium to high salt concentrations. This study was done to identify a salinity threshold level for castor bean emergence and stand establishment. Seedlings were first cultured in organic matter–soil mixed media at different salinity levels (0.5, 3.6, 7.1, 10.4, and 13.6 dS m−1) and then transplanted into pots filled with soils at similar salinity levels (0.4, 3.6, 7.1, 10.4, and 13.6 dS m−1). Emergence, survival, seedling growth, nutrient accumulation, and leaf photosynthetic parameters were determined. The salinity threshold level was identified at 7.1 dS m−1 At this salinity level or lower, the emergence rate and survival rate reached 75% or higher; and seedling growth, nutrient accumulation, and leaf photosynthetic parameters were not severely affected. As the salinity level increased to 10.4 and 13.6 dS m−1, emergence rate dropped to below 70%, and survival rate below 50%. Photosynthetic rate and stomatal conductance were reduced by up to 66% and chlorophyll reading by up to 24%. Nutrient uptake and accumulation were also significantly reduced at these two salinity levels. Our results indicate that castor bean could be cultured in plastic seedling trays filled with organic matter–soil mixed seedling media and then transplanted into conventional soils provided that the salinity levels in seedling media and conventional soils are ≤7.1 dS m−1
Combining Ability and Reciprocal Cross Effects of Elite Quality Protein Maize Inbred Lines in Subtropical Environments
Authors: Machida Lewis , Derera John , Tongoona Pangirayi , MacRobert John 
Published: August 2010

ABSTRACTGeneral combining ability (GCA), specific combining ability (SCA), and reciprocal cross effects information facilitate efficient utilization of inbred lines in a breeding program. A diallel analysis of nine quality protein maize (Zea mays L.) inbred lines was evaluated over seven environments in Zimbabwe. Hybrid × environment interaction was significant for all the traits except for tryptophan content and Quality Index. Thus, phenotyping for tryptophan content and Quality Index can be done using a few environments. There was preponderance of GCA effects for tryptophan content, protein content, kernel endosperm modification, and anthesis dates, while SCA effects were both significant and dominant for grain yield, and were also significant for Quality Index and anthesis dates. Reciprocal effects were significant for Quality Index, tryptophan, and anthesis dates, but on the average they accounted for <13% of the variation among hybrids; hence, they were less important. The cross CML181f × CML176 between heterotic group B inbreds was the highest yielding. Inbred CZL03016 exhibited the most desirable GCA effects for kernel modification, while CML264Q showed the best GCA effects for Quality Index, tryptophan, and protein content. CML264Q would be crucial for use as a donor in breeding for these traits in subtropical maize programs.
Improving Efficiency of Sugarcane Genotype Selection in Florida
Authors: del Blanco Isabel A. , Glaz Barry , Edmé Serge J. 
Published: August 2010

ABSTRACTThe Canal Point (CP) sugarcane (Saccharum spp.) breeding program has developed high‐yielding cultivars for the organic soils of South Florida, but cultivar development has not been as successful for sand soils in this region. Our objectives were to improve final‐stage (Stage 4) selection efficiency of this program by assessing interactions among genotypes, soils, and locations and other sources of variation and by comparing the relationship between repeatability and number of replications as a measure of precision for testing sugarcane genotypes on sand and muck soils. Sources of variation were partitioned for plant‐cane, first‐ratoon, and second‐ratoon data, from 7 yr and five CP series in Stage 4 tested at eight locations on muck soils and two locations on sand soils. Variation related to genotype × location (soil) was highly significant for cane and sugar yields for all series and crops, but most genotype × soil interactions were nonsignificant. This suggested that planting more Stage‐4 tests on sand may improve genotype selection for these soils. The six replications used routinely in Stage 4 provided elevated levels of precision for both soil types. All locations with muck and sand soils in Stage 4 have ample testing resources for discriminating among genotypes. Our results indicate that, to improve sugarcane genotype selection for sand soils, increasing the number of sand locations would be a more successful strategy than increasing replications within locations.
Total Grain‐Arsenic and Arsenic‐Species Concentrations in Diverse Rice Cultivars under Flooded Conditions
Authors: Pillai Tushara R. , Yan Wengui , Agrama Hesham A. , James William D. , Ibrahim Amir M. H. , McClung Anna M. , Gentry Terry J. , Loeppert Richard H. 
Published: August 2010

ABSTRACTArsenic (As) is not an essential element and can be toxic to both plants and animals. Low As concentrations in all foodstuffs, including rice grain, is a desirable goal because of the potential detrimental impacts of As on plant growth and yield and its potential toxicity to humans. Twenty‐five diverse rice (Oryza sativa L.) cultivars, including both indica and japonica subspecies, were grown over a 3‐yr period (2004, 2005, and 2007) on a moderate As‐concentration, paddy soil (Dewitt silt loam, fine, smectitic, thermic Typic Albaqualf) under continuously flooded field conditions. The total grain‐As [TGAs; HNO3/H2O2 digestion and analysis by inductively‐coupled‐plasma mass‐spectroscopy (ICP–MS)] and As‐species [trifluoroacetic acid (TFA) extraction and analysis by high performance liquid chromatography (HPLC) coupled with ICP–MS] concentrations and their relationships with plant‐growth parameters (e.g., heading date and yield) were assessed. The only As species detected in milled (polished) rice grain were inorganic AsIII (arsenite) (iAsIII) and dimethylarsinic acid (with pentavalent As) (DMAsV). Total grain‐As (TGAs) and As‐species concentrations, as well as iAsIII/TGAs ratio, each varied widely between cultivars. Arsenic concentration and speciation were mostly dependent on genotype (G), but there were also significant genotype by year (G × Y) and year (Y) effects that were likely impacted by annual differences in environmental conditions, such as temperature, and local soil characteristics. This study indicates the significant potential for lowering rice‐grain As concentration through genotype selection and plant breeding.
Genetic Variability of Cultivated Rhizoma Peanut
Authors: Maas Andrea L. , Anderson William F. , Quesenberry Kenneth H. 
Published: August 2010

ABSTRACTRhizoma peanut (RP; Arachis glabrata Benth.) is a vegetatively propagated tropical legume that combines high forage nutritive value and long‐term persistence under a wide range of grazing and harvested hay systems. The objectives of this study were to measure the genetic relatedness among 15 RP accessions and assess purity of accessions maintained at different locations. A total of 22 RP clones were tested and included eight duplicate accessions sourced from the national Arachis collections and germplasm collections from Florida, Texas, and Georgia. Fourteen amplified fragment length polymorphism (AFLP) primer combinations produced a total of 951 bands, with an average of 67.92 ± 6.56 bands per primer combination. Analysis by unweighted pair group mean algorithm found genetic similarity coefficients (GSAs) that ranged from 0.21 to 1.0. STRUCTURE analysis found minimal population structure or admixture for the RP lines in this study. The duplicated accessions showed a range of genetic distances from no genetic drift (GSA 1.0) to a high degree of drift (GSA 0.28). Overall, AFLP markers provided sufficient polymorphism to successfully differentiate RP clones and determine when genetic drift occurred. The AFLPs substantiated genetic dissimilarity of newly released cultivars from standard accessions. Results also indicated the potential for genetic drift occurring from spontaneous crossing among field‐grown accessions, which could lead to selection of improved cultivars.
Quantitative Trait Loci Associated with Resistance to Rice Stripe Virus and Small Brown Planthopper Infestation in Rice
Authors: Zhang Y. X. , Jiang L. , Liu L. L. , Wang B. X. , Shen Y. Y. , Wang Q. , Cheng X. N. , Wan J. M. 
Published: August 2010

ABSTRACTRice stripe is a serious viral disease of japonica rice (Oryza sativa L.) cultivars in Asia. Resistance to this disease can be divided into that to rice stripe virus (RSV) and to the pest (small brown planthopper, SBPH). Here we have used a doubled‐haploid (DH) population bred from the cross Zhaiyeqing8 (ZYQ8) × Jingxi17 (JX17) and four separate inoculation methods to genetically dissect the rice stripe resistance present in ZYQ8. Two linked RSV resistance quantitative trait loci (QTLs) were located on chromosome 1, and one on chromosome 11, jointly explaining 30 to 44% of the trait variance. The main‐effect qSTV11 was mapped close to the established RSV resistance gene Stvb‐i For resistance to SBPH, three QTLs were located, mapping to chromosomes 1, 2, and 11, and jointly explaining 44 to 51% of the trait variance. The large‐effect qSBPH1 appears to be a novel QTL conferring a degree of tolerance and antibiosis against SBPH. The positive alleles at all six QTLs were present in ZYQ8. Analysis of a set of chromosome segment substitution lines (CSSLs) in which chromosomal segments of various indica varieties were present in a japonica background showed that rice stripe resistance genes/QTLs are common on the long arm of chromosome 1.
Abundance of SSR Motifs and Development of Candidate Polymorphic SSR Markers (BARCSOYSSR_1.0) in Soybean
Authors: Song Qijian , Jia Gaofeng , Zhu Youlin , Grant David , Nelson Rex T. , Hwang Eun‐Young , Hyten David L. , Cregan Perry B. 
Published: August 2010

ABSTRACTSimple sequence repeat (SSR) genetic markers, also referred to as microsatellites, function in map‐based cloning and for marker‐assisted selection in plant breeding. The objectives of this study were to determine the abundance of SSRs in the soybean genome and to develop and test soybean SSR markers to create a database of locus‐specific markers with a high likelihood of polymorphism. A total of 210,990 SSRs with di‐, tri‐, and tetranucleotide repeats of five or more were identified in the soybean whole genome sequence (WGS) which included 61,458 SSRs consisting of repeat units of di‐ (≥10), tri‐ (≥8), and tetranucleotide (≥7). Among the 61,458 SSRs, (AT)n, (ATT)n and (AAAT)n were the most abundant motifs among di‐, tri‐, and tetranucleotide SSRs, respectively. After screening for a number of factors including locus‐specificity using e‐PCR, a soybean SSR database (BARCSOYSSR_1.0) with the genome position and primer sequences for 33,065 SSRs was created. To examine the likelihood that primers in the database would function to amplify locus‐specific polymorphic products, 1034 primer sets were evaluated by amplifying DNAs of seven diverse Glycine max (L.) Merr. and one wild soybean (Glycine soja Siebold & Zucc.) genotypes. A total of 978 (94.6%) of the primer sets amplified a single polymerase chain reaction (PCR) product and 798 (77.2%) amplified polymorphic amplicons as determined by 4.5% agarose gel electrophoresis. The BARCSOYSSR1.0 SSR markers can be found in SoyBase (http://soybase.org; verified 21 June 2010) the USDA‐ARS Soybean Genome Database.
Genetic Diversity of Widely Used U.S. Sorghum Hybrids 1980–2008
Authors: Smith Stephen , Primomo Valerio , Monk Roger , Nelson Barry , Jones Elizabeth , Porter Kay 
Published: August 2010

ABSTRACTSixty‐three sorghum [Sorghum bicolor (L.) Moench] hybrids that are, or have been, widely used in the United States were profiled using 167 simple sequence repeat (SSR) markers. Genetic distance and cluster analysis determined that 43 (68%) of the hybrids formed seven groupings, with each group containing hybrids commercialized by a single breeding organization. Groupings were also reflective of known pedigrees. Hybrids released by different organizations were not very closely associated with one exception of two hybrids. Groupings had limited association with the decade that the hybrid was released. Numbers of alleles per locus have been constant during the past three decades with gain in new alleles being balanced by loss of other alleles. Hybrids released during the 2000s showed the least number of new alleles compared to the previous two decades. Much of the SSR allelic diversity that was introduced via the Sorghum Conversion Program that converted tropical germplasm to be day‐length neutral has been deployed on U.S. farms. Continued monitoring of genetic gain and genetic diversity are important components of sustainable plant breeding strategies.
Genetic Variation in Testcrosses and Relationship between Line per se and Testcross Performance for Resistance to Gibberella Ear Rot in Maize
Authors: Bolduan C. , Miedaner T. , Utz H. F. , Dhillon B. S. , Melchinger A. E. 
Published: August 2010

ABSTRACTGibberella ear rot (GER), caused by Fusarium spp., is a major concern in maize production in Central Europe, and development of hybrid cultivars having GER resistance is an important breeding goal. The objectives of the present study were to (i) evaluate the variation in testcross performance (TP) of European maize germplasm for GER resistance and deoxynivalenol (DON) contamination, (ii) estimate variance components, heritabilities, and correlations of these traits, and (iii) examine the relationship between line per se performance (LP) and TP. Testcrosses of 30 diverse flint inbred lines with two dent inbred testers were evaluated in four environments under artificial inoculation. Data were recorded on severity of GER and concentration of DON. There was substantial GER development and the range of both traits was greater for LP than TP. Estimates of genotypic and genotype × environment interaction variances were significant for testcrosses with both testers. Genotypic variances were generally higher for LP than for TP in each testcross set. Correlations between LP and TP were moderate ( ≤ 0.57) for GER rating and DON concentration. We recommend multi‐stage selection to develop GER resistant maize hybrids based on evaluation of GER resistance under artificial inoculation for (1) LP in one environment followed by (2) TP evaluation in two to three environments. Only the most promising testcrosses should be tested for DON concentration.