bluuebunny/crossref_metadata_2025 huggingface dataset:
Field‐Based Estimates of Heritability and Genetic Correlations in Hop
Authors: Henning John A. , Townsend M. Shaun
Published: June 2005

Hop (Humulus lupulus L. var. lupulus) is grown worldwide for the production of the dried female inflorescence (strobulus), or cones, used principally for the bittering and flavoring of beer. Information is scant on the inheritance of traits of economic importance in hop, and present knowledge is based on historical data rather than designed experimental investigation. The objective of this study was to estimate the heritability of and genetic correlation among six traits: yield (YLD), α‐acid (ALP) concentration, β‐acid (BET) concentration, cohumulone (COH) percentage, colupulone (COL) percentage, and xanthohumol (XAN) concentration. Twenty‐five full‐sib families were developed by crossing five randomly chosen females and five randomly chosen males in a North Carolina Design II mating design. Plants were transplanted into the field in a randomized complete block (RCB) design with four replicates. Data were recorded for two years. Heritabilities for all traits were moderate to high using variance components estimated from males. With the exception of heritability estimates for YLD and ALP, all other traits were not significantly different from zero using female variance components as estimators. Pooled estimates of heritability yielded more reasonable estimates with lowest heritability for BET (h2 = 0.57 ± 0.19) and highest for COL (h2 = 0.89 ± 0.02). Pooled estimates of genetic correlations ranged from r = 0.28 (ALP and YLD) to r = 0.92 (YLD and XAN). Finally, correlations between coefficients of coancestry (COA) between pairs and their respective mean offspring data were significant for ALP, COL, and XAN suggesting that for these traits at least, COA values may be predictive of potential heterosis. On the basis of these data, selection for COL, ALP, and YLD would be successful using simple selection protocols such as phenotypic recurrent or mass selection. The likelihood of success when selecting for BET and XAN would be low, thus requiring one of the genotypic recurrent selection techniques. Selection against COH (a negative factor in brewing) appears problematic because of positive correlations with all other traits. The information presented in this study is the first published record of field‐based estimates of narrow‐sense heritability and genetic correlations in hop and will aid hop breeders working with these traits.
Minimizing Thatch and Mat Development in a Newly Seeded Creeping Bentgrass Golf Green
Authors: McCarty Lambert B. , Gregg Matthew F. , Toler Joe E. , Camberato James J. , Hill Hoke S.
Published: June 2005

Excessive (>1.3 cm) thatch and mat layering of turfgrass is considered undesirable because it reduces hydraulic conductivity, water infiltration, increases localized dry spots and pest problems, and reduces pesticide effectiveness and turf tolerance to temperature extremes. The objective of this 2‐yr study was to determine the efficacy of topdressing alone and in combination with several mechanical and biological methods to control thatch–mat accumulation in a newly established ‘L‐93’ creeping bentgrass [Agrostis stolonifera L. var palustris (Huds.) Farw.] sand‐based golf green. Mechanical and biological methods included vertical mowing at various depths and timings, core cultivation, grooming, a biological thatch control agent (Thatch‐X), and combinations of core cultivation with grooming, core cultivation with vertical mowing, and core cultivation combined with grooming and vertical mowing. No treatment prevented thatch–mat accumulation, and thatch–mat depth for all treatments were similar to, or greater than, the untreated at the end of the study. Increases in percent organic matter content during the study ranged from 53% for core cultivation combined with grooming and vertical mowing to 123% for the untreated. Combinations of core cultivation plus vertical mowing with or without grooming were the most effective at minimizing thatch–mat accumulation. These treatments decreased percent organic matter 38 and 45%, respectively, compared with the untreated. Surface hardness was reduced an average of 19% by treatments that included core cultivation, and the cultivation treatments increased water infiltration rates an average of 58% in 2001 and 188% in 2002 compared with the untreated. Turf quality was not adversely affected by any management practice and remained acceptable (≥7.0) throughout the study.
Development and Evaluation of a Mini Core Collection for the U.S. Peanut Germplasm Collection
Authors: Holbrook C. Corley , Dong Weibo
Published: June 2005

A core collection (831 accessions) has been developed to represent the U.S. Arachis hypogaea L. germplasm collection. This core collection has been shown to be effective in improving the efficiency of identifying genes of interest in the entire germplasm collection. However, an even smaller subset of germplasm is needed for traits which are difficult and/or expensive to measure. The objectives of this study were to select a core of the core collection and to evaluate the usefulness of this subset of germplasm to identify genes of interest in peanut. Data for eight above ground and eight below ground morphological characteristics were measured for each accession in the core collection. Cluster analysis was used on these data to partition the core accessions into groups which, theoretically, are genetically similar. Random sampling was then used to select a 10% sample from each group. The result was a core of the core collection (mini core) consisting of 112 accessions. Examination of morphological data indicated that the majority of genetic variation expressed in the core collection has been preserved in this core of the core collection. Data on disease resistances for accessions in the core collection were collected and used to determine retrospectively how effective the use of a mini core collection would have been in identifying sources of resistance in the core collection. Results indicated that the mini core collection can be used to improve the efficiency of identifying desirable traits in the core collection. For resistance to late leaf spot (Cercosporidium personatum (Berk. & M. A. Curtis), the use of a mini core collection would have improved the efficiency of identifying resistant accessions in the entire collection. The core of the core approach should be particularly useful for traits which are difficult and/or expensive to measure.
Genetic Analysis of Resistance Genes for the Rice Gall Midge in Two Rice Genotypes
Authors: Kumar Arvind , Jain Abhinav , Sahu R. K. , Shrivastava M. N. , Nair Suresh , Mohan Madan
Published: June 2005

Asian rice gall midge (Orseolia oryzae Wood‐Mason) is the most destructive pest of rice (Oryza sativa L.) in several regions of South and Southeast Asia. Resistance to gall midge is primarily governed by single dominant genes in rice, thus newly evolving biotypes are able to overcome resistance genes rendering these genes ineffective. The objective of this study was to identify the gall midge resistance genes present in BG 380‐2 and ‘Gurmatia’ and their relationship to known resistance genes. F1, F2, and F3 populations developed from crosses of BG 380‐2 and Gurmatia with susceptible cultivars and differentials, possessing the known resistance genes, were screened for their reactions against gall midge biotype 1. Inheritance studies identified a single dominant gene for gall midge resistance in both BG 380‐2 and Gurmatia. Allelic study revealed the gall midge resistance gene present in BG 380‐2 was nonallelic to all currently known genes (Gm1, Gm2, gm3, Gm4, Gm5, Gm7, Gm8, and Gm9) that impart resistance against gall midge biotype 1 population and is designated as Gm10 The gall midge resistance gene present in Gurmatia was allelic to the Gm1 gene previously identified. This new resistance gene, Gm10, in BG 380‐2 will be useful in breeding new varieties and for pyramiding multiple genes for durable resistance to rice gall midge.
Pollen‐Mediated Gene Flow from Blue Aleurone Wheat to Other Wheat Cultivars
Authors: Hanson B. D. , Mallory-Smith C. A. , Shafii B. , Thill D. C. , Zemetra R. S.
Published: June 2005

Cross‐pollination among wheat (Triticum aestivum L.) cultivars historically has not been a major concern for wheat producers. However, with the introduction of genetically engineered wheat, there may be a need to ensure genetic purity, which will require knowledge of the frequency and distance that pollen‐mediated gene flow can occur in wheat. This information will be necessary to develop (i) isolation distances that maintain predictable degrees of genetic purity in seed wheat production and (ii) practices to manage pollen‐mediated gene flow in commercial wheat production. Field experiments were conducted from 2000 to 2003 at five locations in Oregon, Idaho, and Washington to determine the potential for pollen‐mediated gene flow among winter wheat cultivars. Each experiment was designed as a Nelder wheel with 16 equally spaced rays extending away from a central pollen source of blue aleurone wheat. Each ray was 46 m long and contained two rows each of an early‐ and late‐flowering soft white wheat cultivar. Seed samples were collected at 1.8‐m intervals along each ray and examined for blue seed, which indicated successful hybridization with the pollen source. Although blue seed was found in some samples at all five locations, most samples (98%) contained no blue seed. Pollen‐mediated gene flow generally was in the direction of the prevailing wind and tended to occur more often at the sites with lower temperature and higher humidity during pollination. The maximum distance that gene flow was detected was 42 m from the pollen source and the maximum outcrossing in an individual sample was 0.45%. At four locations, no outcrossing was detected beyond 30 m from the pollen source; however, at one site, 13% of the blue seed was found between 30 and 42 m. Pollen‐mediated gene flow potential may differ for other wheat cultivars and environmental conditions. Depending on the required genetic purity standards for wheat seed, an isolation distance of 45 m or more may be required.
Prospects for Hybrid Breeding in Winter Triticale: I. Heterosis and Combining Ability for Agronomic Traits in European Elite Germplasm
Authors: Oettler G. , Tams S. H. , Utz H. F. , Bauer E. , Melchinger A. E.
Published: June 2005

Triticale (×Triticosecale Wittmack) (genomes AABBRR, 2n = 6x = 42) hybrid breeding and heterosis have received increased attention in recent years, but a comprehensive study is lacking. We investigated (i) the level of heterosis, (ii) the relative importance of general combining ability (GCA) vs. specific combining ability (SCA), (iii) correlations between GCA and line per se performance, (iv) trait correlations in parents and hybrids, and (v) prospects for hybrid breeding. Two hundred nine F1 hybrids of winter triticale, produced by a chemical hybridizing agent, together with their 57 female parents and five tester (male) lines were evaluated in six environments in Germany during the season 2001–2002. Midparent heterosis for grain yield averaged 10.3% and varied from –11.4 to 22.4%, whereas better‐parent heterosis averaged 5.0% and varied from –16.8 to 17.4%. Midparent heterosis was also positive for 1000‐kernel weight, number of kernels per spike, test weight, and plant height but negative for number of spikes per square meter, falling number, and protein concentration. GCA variance σ̂2GCA was more important than SCA variance σ̂2SCA for all traits except grain yield and protein concentration. For most traits, GCA × location and SCA × location interaction variances were small relative to σ̂2GCA and σ̂2SCA, respectively. Genetic correlations between midparent and hybrid performance and between GCA effects and line per se performance showed similar trends, being moderate for grain yield and protein concentration and higher for the other traits. We concluded that grain yield heterosis in winter triticale crosses from parents in the current European germplasm pool is adequate to justify continuing research on hybrid breeding. By selecting parents for combining ability and establishing genetically diverse heterotic groups, a midparent grain yield heterosis of 20% could presumably be surpassed. Further information is needed on F1 seed production and the cytoplasmic male sterility system.
Pollen‐Mediated Gene Flow in California Cotton Depends on Pollinator Activity
Authors: Van Deynze Allen E. , Sundstrom Frederick J. , Bradford Kent J.
Published: June 2005

Many cotton (Gossypium hirsutum L.) pollination studies have been performed in the southern USA, but no data exist for California. In this study, we measured pollen‐mediated gene flow (PGF) in four directions over 2 yr from herbicide‐resistant source plots in upland cotton in the California cotton growing region and in a region with high pollinator activity. In addition, samples were taken from fields of conventional varieties at varying distances from fields planted with herbicide‐resistant varieties to assess PGF under commercial production conditions. A seedling herbicide bioassay confirmed by DNA tests was used to measure PGF. PGF was independent of direction from the source plot and declined exponentially with increasing distance from 7.65% at 0.3 m to less than 1% beyond 9 m when there was high pollinator activity. In the absence of high pollinator (honeybee, Apis mellifera L.) populations, PGF was less than 1% beyond 1 m. Pollen flow in commercial fields was consistent with the experimental plot data, with only 0.04% PGF detected at 1625 m (1 mile). This study confirms that PGF decreases exponentially with distance in cotton grown under California conditions and is low in the absence of pollinators, although sporadic occurrence of PGF can be detected up to 1625 m.
Inheritance and Chromosomal Assignment of Powdery Mildew Resistance Genes in Two Winter Wheat Germplasm Lines
Authors: Srnić G. , Murphy J. P. , Lyerly J. H. , Leath S. , Marshall D. S.
Published: June 2005

Powdery mildew of wheat (Triticum aestivum L.), caused by Blumeria graminis DC f. sp. tritici Em. Marchal, occurs annually in eastern North America resulting in reduced grain yield and end‐use quality in susceptible cultivars. The objectives of this study were to determine the inheritance, chromosomal location, and linkage with molecular markers of powdery mildew resistance genes in the two recently released germplasm lines NC96BGTA4 and NC99BGTAG11. Between 99 and 194 F2:3 progenies plus parents in two populations, ‘Saluda’ × NC96BGTA4 and Saluda × NC99BGTAG11, were evaluated in greenhouse and field nurseries for reaction to powdery mildew infection. Results indicated that the germplasm lines each contained a different, partially dominant, major resistance gene. The two segregating populations were subjected to amplified fragment length polymorphism (AFLP) and simple sequence repeat, or microsatellite (SSR) analyses. Both resistance genes were located on the long arm of chromosome 7A. The most likely locus order indicated that the resistance gene in NC96BGTA4 was flanked by the SSR loci Xbarc292 and Xwmc525 The resistance gene in NC99BGTAG11 was most likely flanked by the AFLP markers XE38M54‐196 and XE36M55‐126, and the SSR loci Xgwm332 and Xwmc525 Both genes mapped to a chromosome arm that contains the powdery mildew resistance loci Pm1 and Pm9 The resistance genes in the two germplasms are different from the Pm1a allele. Our mapping results suggested that the resistance genes were not alleles at the Pm1 or Pm9 loci, but further allelism tests are necessary to determine the relationships both between the two genes themselves and between the two genes and named Pm loci on chromosome 7AL.
Construction and Characterization of a BAC Library of a Cold‐Tolerant Hexaploid Wheat Cultivar
Authors: Ratnayaka Indira , Båga Monica , Fowler D. Brian , Chibbar Ravindra N.
Published: June 2005

A bacterial artificial chromosome (BAC) library was constructed from DNA of a commercially grown winter wheat cultivar (Triticum aestivum L. cv. Norstar) that is highly tolerant to low temperatures (LT50 = −24°C). The library was produced from nuclear leaf DNA that was partially digested with HindIII and inserted into pCC1BAC vector. In excess of 1.2 × 106 clones propagated in E. coli were obtained, archived in 384‐well microtitre plates and stored at −80°C. More than 97.1% of the recombinant plasmids contained inserts and were free from organelle DNA contamination. Analysis of 119 randomly isolated clones revealed insert sizes ranging from 17 to 262 kb with 26% of the inserts exceeding 100 kb. The average insert size was 75 kb and the genome coverage of the library was theoretically 5.5 times the haploid genome equivalent. This corresponds to a 99.6% probability of recovering any specific Norstar DNA sequence from the library. Screening of the library with nine simple sequence repeat (SSR) locus‐specific markers supported a >4.4‐fold genome coverage. The BAC library was gridded onto high‐density filters and will be used for isolation of genetic loci associated with cold‐tolerance and grain quality traits.
Batch Analysis of Digital Images to Evaluate Turfgrass Characteristics
Authors: Karcher Douglas E. , Richardson Michael D.
Published: June 2005

Techniques using digital image analysis have been recently developed to evaluate turfgrass stands for percent green cover and average color. Manually analyzing digital images may become cumbersome and tedious if turf field trials contain many plots or if images are collected at frequent intervals for analysis. The objective of the following work was to develop a user‐friendly macro capable of automated batch analysis of an unlimited number of digital images. A macro named “Turf Analysis” was written to batch analyze images using SigmaScan Pro software. The macro, which requires less than 1 min of manual execution, performs percent cover and/or color analysis on an unlimited number of images and automatically saves the results into a spreadsheet file. The macro is freely available to download.
Changes in the Histology of Cold‐Hardened Oat Crowns during Recovery from Freezing
Authors: Livingston David P. , Tallury Shyamalrau P. , Premkumar Ramaswamy , Owens Shirley A. , Olien C. Robert
Published: June 2005

The survival of cereal crops during winter depends primarily on the ability of tissue in the crown to withstand various stresses encountered during freezing. Freeze‐induced damage to specific regions of oat (Avena sativa L.) crowns was evaluated by sectioning plants at various stages of recovery after they had been grown and frozen under controlled conditions. Our results confirmed those reported for barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) that the apical meristem was apparently the tissue in the crown most tolerant of freezing. Photographs of sections during recovery provided evidence that the apical meristem within the crown survived freezing in plants that were rated as nonsurvivors. Closer examination revealed abnormal nuclei in many cells of plants that had been frozen. These cells with condensed and dark red chromatin resembled the description of nuclear pycnosis found in mammalian cells damaged by radiation, extreme abiotic stress, and various carcinogens. The crown meristem complex was separated from the crown and fractionated into two regions: the upper portion of the crown meristem complex, called the apical region, and the lower portion called the crown core. The dry weight of both the apical region and crown core increased during cold‐hardening but the increase in dry weight was higher in the crown core than in the apical region. During cold‐hardening the percentage of total water freezing at −2°C became lower and after 3 wk was 50 and 47% in the apical region and the crown core, respectively. The initial freezing rate of the apical region was higher than that of the crown core and reached equilibrium about 2 h earlier than the crown core. Differences are discussed in relation to the freezing survival of specific tissue.
Molecular Marker Diversity and Field Performance in Commercial Cotton Cultivars Evaluated in the Southwestern USA
Authors: Zhang Jinfa , Lu Y. , Cantrell R. G. , Hughs E.
Published: June 2005

Genetic diversity in modern upland cotton cultivars (Gossypium hirsutum L.) is thought to be narrow, thus limiting genetic advance. Robust information on the genetic relatedness among currently grown cotton cultivars is lacking. The objectives of the present study were to field test a sample of elite commercial cotton cultivars, including many transgenic cultivars representing the major cottonseed companies, and to evaluate their genetic divergence using simple sequence repeat (SSR) markers. Eighty‐eight SSR primer pairs were chosen for genotyping that provided 177 SSRs. Jaccard's genetic similarity coefficients among 24 genotypes ranged from 0.694 to 0.936, with an average of 0.772, indicating that sufficient genetic diversity does exist within our sample of commercial upland cotton. Genetic similarities among cultivars from the same seed companies were generally higher than the mean of all cultivars and grouped into six major groups: two Deltapine (DP), one Stoneville (ST), one FiberMax (FM), and two New Mexico (NM) Acalas. One California Acala cultivar of New Mexico origin, developed by Phytogen (PHY), did not group with New Mexico Acala germplasm. Texas High Plains stripper type cultivars were distant from picker types and formed independent groups. Under New Mexico growing conditions, DP and ST cultivars yielded higher but produced lower fiber quality, while NM Acala cotton had lower yield but higher fiber quality. The PHY and FM cultivars were intermediate in cotton yield and fiber quality. Six SSR markers were identified to be significantly correlated with fiber yield or quality among the cultivars tested, providing impetus to validate the marker–trait associations.
Epistasis in Cassava Adapted to Midaltitude Valley Environments
Authors: Pérez J. C. , Ceballos H. , Jaramillo G. , Morante N. , Calle F. , Arias B. , Bellotti A. C.
Published: June 2005

Little is known about the inheritance of agronomic traits in cassava (Manihot esculentaCrantz). The vegetative multiplication of cassava allows cloning of individual genotypes, and separates environmental from genetic variation in the within‐family variation. Knowing the magnitude of between‐ and within‐family variation is important for defining breeding strategies and for measuring different components of genetic variances, particularly the seldom‐estimated epistasis. A group of nine genotypes, adapted to midaltitude environments, was used for a diallel study. Thirty clones were obtained from every F1cross (each clone was represented by six plants), and planted in three replications at two locations. Statistical differences among crosses were found for fresh‐root yield, harvest index, root dry‐matter content, and reaction to mites (Mononychellus tanajoaBondar) and to whiteflies (Aleurotrachelus socialisBondar). General combining ability (GCA) was significant for all traits except fresh‐root yield and dry‐matter content, and specific combining ability (SCA) was significant for all traits except whitefly damage score. Fresh‐root yield was the only trait with significant epistatic effects, which, combined with a large dominance variance, suggested a prevalence of nonadditive effects. The introduction of inbreeding would be one approach for the efficient exploitation of these nonadditive effects found for fresh‐root yield. For the remaining traits, epistasis was negligible and current schemes exploiting additive effects may suffice.
Ozone Impacts on Competition between Tomato and Yellow Nutsedge: Above‐ and Below‐Ground Effects
Authors: Shrestha Anil , Grantz D. A.
Published: June 2005

Tomato (Lycopersicon esculentum L.) production in the San Joaquin Valley (SJV) of California is challenged by air pollution and weeds. Differential ozone (O3) tolerance of tomato cultivars and weed species may alter crop–weed competition. A study was conducted in open top chambers (OTCs) at the Kearney Research and Extension Center, Parlier, CA, to assess O3 impacts on competition between tomato and a C4 weed, yellow nutsedge (Cyperus esculentus L.). Processing tomato (cv. HD 8892 and EMP 113) and nutsedge (locally collected biotypes) were grown in pots for 4 to 8 wk. Population ratios ranged from a tomato plant alone (0:1) to a nutsedge plant alone (1:0), and included 1:1, 2:1, and 3:1. Ozone exposures were to 12 h means of 19.8, 78.0, and 142.3 nL/L. Chlorophyll content of leaves of tomato and nutsedge was reduced with increasing O3 Carbon assimilation was reduced in nutsedge but not in tomato. Root respiration was not affected in either species. Tomato main stem length, shoot, and root biomass declined at the highest O3 concentration under all levels of nutsedge competition. Nutsedge was much less affected. In the absence of O3 exposure, interspecific competition (all population ratios combined) reduced tomato and nutsedge shoot and root biomass. Tomato was more sensitive to O3 than nutsedge, but nutsedge was more sensitive to competition than was tomato. Nutsedge allocated greater resources to reproductive structures (tubers) at the highest O3 exposure. As nutsedge reduced tomato productivity under low and moderate O3 concentrations, it may become even more difficult to control, exert greater competitiveness, and colonize fields more rapidly because of greater tuber production, in projected near‐future environments. Under conditions of greatly increasing ambient O3 concentrations, nutsedge may become less competitive because of its sensitivity to O3
Simultaneous Agronomic and Molecular Characterization of Genotypes via the Generalised Procrustes Analysis: An Application to Cucumber
Authors: Bramardi S. J. , Bernet G. P. , Asíns M. J. , Carbonell E. A.
Published: June 2005

Characterizing entries in a germplasm bank by molecular markers and/or agronomic attributes is a common practice, but studies that simultaneously use molecular and agronomic traits are less frequent. Generalised Procrustes Analysis (GPA) was used to determine the relationships among 41 entries of cucumber (Cucumis sativus L.) via the simultaneous use of 16 agronomic traits (nine qualitative variables and seven quantitative variables) and 33 random amplified polymorphic DNA (RAPD) markers using a set of 11 primers. Other techniques like generalization of the simple matching coefficient, Gower's general similarity coefficient, and discretizing the quantitative variables were compared with GPA. The ordinations of cultivars using each trait individually did not fully characterize the cultivars. In fact, on the basis of the qualitative traits, only two groups were formed, with cultivars belonging to Beth‐α and Dutch constituting a single group and the slice and gherkin types another group. The quantitative traits and also the molecular traits further separated the cultivars belonging Beth‐α and Dutch types. The utilization of all variables together showed a greater discrimination power of genotypes. Four groups were defined which were consistent with Dutch, gherkin, slice, and Beth‐α types. GPA was the most precise technique to cluster the entries. The final configuration was an average of the individual configurations. For other methods, those traits with more variants (but not necessarily more genetic information) had more influence on the final results. Besides, GPA allowed a deeper study of the relationships among relative ordinations of a same genotype under different types of descriptors to establish concordance between characterizations.
Calcium and Magnesium Effects on Ammonia Adsorption by Soil Clays
Authors: Dontsova Katerina M. , Norton L. Darrell , Johnston Cliff T.
Published: June 2005

Anhydrous ammonia is a widely used N fertilizer and its interactions with soils and soil clays play an important role in its environmental fate. This study was conducted to determine the quantity and forms of ammonia adsorbed by clay‐sized fractions of soils as a function of water content, exchangeable cation, and organic matter (OM). Fourier transform infrared spectroscopy was used to evaluate in situ the mechanisms of interaction of H2O, NH3, and NH+4 with the clay‐size fractions of a Blount loam (fine, illitic, mesic Aeric Epiaqualfs) and a Fayette silty clay loam (fine‐silty, mixed, mesic, superactive Typic Hapludalfs). Due to NH3 dissolution in adsorbed water more total N was sorbed at high (90%) than at low (2%) relative humidity (RH) despite decrease in the amount of NH+4 sorbed. At high RH, the amount of NH+4, NH3, and total N increased by 12 to 23% on the Mg‐exchanged compared with the Ca‐exchanged soil clays. Of the two soil clays, the smectitic sample (Fayette) sorbed more of both N species than the illitic sample (Blount). Samples with OM removed adsorbed significantly more ammonia than untreated samples. The mechanism suggested for ammonia sorption by soil clays is a combination of protonation on water associated with metal cations, coordination to the exchangeable cations and dissolution in pore water. Soil clays can retain significant amounts of ammonium in excess of the cation exchange capacity (CEC) and out of competition for exchange sites. Dissolved NH3 constituted the majority of N adsorbed by the sample at high RH, which is typical of field conditions.
Donor Agencies' Involvement in Reproductive Health: Saying One Thing and Doing Another?
Authors: Mayhew Susannah H. , Walt Gill , Lush Louisiana , Cleland John
Published: June 2005

The debates about what services constitute reproductive health, how these services should be organized, managed, and delivered, and what the role of donor agencies' support should be mirror the long-standing debates on how best to implement primary health care. After briefly reviewing the development of the discourse on primary health care and reproductive health, the authors present results of qualitative research in Ghana, Kenya, and Zambia that indicate a range of factors influencing and explaining the way donors operate in these countries and consider the implications of these results for the delivery of comprehensive reproductive health services. These findings are compared with South Africa, a country with limited donor activity. In the light of the complex interplay of factors, the authors suggest that donors' words and actions frequently do not correlate. Conclusions are drawn as to the potential for donor support for integrated reproductive health service delivery in sub-Saharan Africa, drawing on the research to provide lessons and a reappraisal of the role of donors in health sector aid.
Process Evaluation of a Repeat Pregnancy Prevention Program for African-American Adolescent Mothers
Authors: O'Rourke Kathleen M. , Key Janice D.
Published: June 2005

Purpose:

Process evaluation of adolescent pregnancy prevention programs provides important data which can identify program coverage, dosage, and participants' perception of specific components.

Methods:

A school-based youth development peer group with integrated medical care in Charleston, South Carolina, was evaluated for specific process objectives. Quantitative measurements included enrollment and participation rates. Qualitative measurements included focus groups with participants and in-depth interviews with parents and school personnel.

Results:

Overall, 95% of eligible girls participated in the project, with an average attendance of 42%. Participants found support of other teen parents beneficial and privacy concerns a barrier. Parents and school personnel viewed the program positively, and saw it as a means of providing the girls direction.

Conclusions:

This evaluation demonstrated achievement of program objectives for enrollment and participation rates and identified components contributing to program success. This evaluation method may be useful in guiding program implementation and demonstrating efficacy in conjunction with outcome evaluations.
Crystal growth rates of paracetamol in mixtures of water + acetone + toluene
Authors: Granberg Roger A. , Rasmuson Åke C.
Published: June 2005

Crystal growth rates of paracetamol (4‐hydroxyacetanilide) have been determined by seeded isothermal desupersaturation experiments at 16 °C in 23 different solvent mixtures of water + acetone + toluene. Parameters of different growth rate equations have been estimated by direct nonlinear optimization. At equal thermodynamic driving force, the growth rate depends on the composition of the solvent mixture. In the surface diffusion spiral growth model, this dependency can be described in terms of the interfacial energy between the solid and the solution. A reasonable prediction of the influence of the solvent composition on this interfacial energy is obtained if a proper estimation of the enthalpy of dissolution is done. For the case of paracetamol crystals growing in water + acetone + toluene mixtures this estimation needs to include an estimation of the entropy of fusion at the temperature of growth as well as of the nonideal entropy of mixing. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Simulation of sedimentation of polydisperse suspensions: A particle‐based approach
Authors: Bargieł Monika , Ford Robert A. , Tory Elmer M.
Published: June 2005

The global behavior of sedimenting monodisperse suspensions of rigid spheres can be deduced from the flux plot, but this approach is not available for polydisperse suspensions. The rapid increase in computing power has made simulation an attractive method. Sedimentation of suspensions with many species can now be handled easily. Two sources of difficulty, generation of a concentration gradient and control of fluctuations in concentration, can be overcome by choosing the controlling concentration as that immediately below the test sphere. Applied to randomly distributed particles, our deterministic algorithm yields the ensemble behavior of each species and prepares the way for stochastic simulations by correcting density inversions. The simplicity and generality of the method make it feasible to test any theoretical or empirical model against any experimental data. Simulating the experiments and comparing the simulated and experimental results is illustrated. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Successful hematopoietic stem‐cell transplantation in multicentric Castleman disease complicated by POEMS syndrome
Authors: Ganti Apar Kishor , Pipinos Iraklis , Culcea Eliad , Armitage James O. , Tarantolo Stefano
Published: June 2005

A 39‐year‐old male presented with pedal edema, pleural effusion, splenomegaly, and generalized lymphadenopathy. Serum protein electrophoresis demonstrated the presence of a monoclonal protein. Histological examination of the spleen following splenectomy showed multifocal vascular proliferation and angiovascular lesions consistent with multicentric Castleman disease. He was treated with steroids and rituximab, but without improvement. The patient was found to have portal venous thrombosis and lower extremity arterial thrombosis. He then received combination chemotherapy with cyclophosphamide and mitoxantrone but developed a severe inflammatory polyneuropathy that left him disabled and wheelchair‐bound. A diagnosis of multicentric Castleman disease with POEMS syndrome was made, and he then received high‐dose chemotherapy with melphalan followed by autologous peripheral blood stem‐cell transplantation. Following transplantation, his nerve conduction studies improved and his serum protein electrophoresis normalized. He is currently ambulatory and does not need wheelchair assistance. Hematopoietic stem‐cell transplantation may be a treatment option for patients with multicentric Castleman disease and POEMS syndrome. Am. J. Hematol. 79:206–210, 2005. © 2005 Wiley‐Liss, Inc.
Prevalence of elevated antithyroid antibodies and antinuclear antibodies in children with immune thrombocytopenic purpura
Authors: Pratt Ellen L. , Tarantino Michael D. , Wagner Debra , Hirsch Pescovitz Ora , Bowyer Suzanne , Shapiro Amy D.
Published: June 2005

The prevalence and significance of autoantibodies found at the time of diagnosis of childhood ITP were studied to correlate their presence with risk for development of chronic ITP. Children presenting with acute or chronic ITP to The James Whitcomb Riley Hospital for Children between July 1993 and September 1994 were tested at study entry and followed for the presence of antithyroid antibodies (ATA), antinuclear antibodies (ANA), Coombs' reactivity, and anti‐human immunodeficiency virus (HIV) antibodies. Grouped data were evaluated for significance using Fisher's exact t‐test. Thirty‐one patients were enrolled in the study with a median age of 8 years (range 17 months–16 years) and male‐to‐female ratio of 1:1.8. Forty‐two percent of these children had an acute course of ITP, and 58% of children had a chronic course of ITP. Of children with acute ITP, three (23%) of the patients had an acute nonplatelet autoantibody detected. Of the children with chronic ITP, six (33%) of the children had at least one abnormal antibody value. Five children (16%) tested positive for ATA: 2 children with acute ITP and 3 with chronic ITP. Five children had positive ANA, and of these children, 4 (80%) had chronic ITP. Sixty‐seven percent of patients testing positive for autoantibodies were female, and 67% of all patients were 12 years of age or older. Three patients, 1 with acute ITP and 1 with chronic ITP, had insignificant abnormal thyroid function tests (these children had minimally elevated T3 with otherwise normal thyroid function, and none of these children had autoantibodies). No patients included in the study tested positive for HIV. Our results suggest that patients with acute ITP who also have other autoantibodies may be more likely to develop chronic ITP than those lacking these autoantibodies. Larger studies are needed to determine whether the presence of ATA or ANA is predictive of clinically significant autoimmune disease. Am. J. Hematol. 79:175–179, 2005. © 2005 Wiley‐Liss, Inc.
Mini‐BEAM and autologous hematopoietic stem‐cell transplant for treatment of post‐transplant lymphoproliferative disorders
Authors: Komrokji Rami S. , Oliva Jamie L. , Zand Martin , Felgar Raymond , Abboud Camille N.
Published: June 2005

Post‐transplant lymphoproliferative disorder (PTLD) represents a spectrum of lymphoid proliferative diseases seen as result of immunosuppression in recipients of solid organ or hematopoietic stem‐cell transplantation. Options of treatment include reduction or discontinuation of immunosuppressive agents, antiviral drugs, rituximab, chemotherapy, and radiation. We report two unique cases of PTLD (CNS and plasmacytoma‐like) treated successfully with salvage chemotherapy, mini‐BEAM chemotherapy, and autologous stem‐cell transplant. In both cases, patients were also treated with sirolimus and prednisone as immunosuppression, and neither patient rejected their solid organ transplants. With over 30 months of follow‐up, both patients remain in complete remission with excellent allograft function. Am. J. Hematol. 79:211–215, 2005. © 2005 Wiley‐Liss, Inc.
Veno‐occlusive disease of the liver associated with chronic myelomonocytic leukemia treated with vincristine and standard doses of cytarabine
Authors: Boula A.M. , Mantadakis E. , Xilouri I.M. , Christoforidou A.V. , Foudoulakis A.M. , Samonis G.
Published: June 2005

A unique case of a 72‐year‐old man with chronic myelomonocytic leukemia (CMML) who developed hepatic veno‐occlusive disease (VOD) after treatment with a single dose of vincristine and standard doses of cytarabine is described. Unexpected peroneal nerve palsy suggestive of vincristine neurotoxicity occurred concurrently and pointed to vincristine as the most likely cause of the VOD. To the best of our knowledge, association between vincristine and hepatic VOD has not been previously described in chemotherapy‐naive patients with CMML. Am. J. Hematol. 79:216–219, 2005. © 2005 Wiley‐Liss, Inc.
Venous thromboembolism prevention in the acutely ill medical patient: A review of the literature and focus on special patient populations
Authors: Pendleton Robert , Wheeler Michelle , Rodgers George
Published: June 2005

Although venous thromboembolism (VTE) is a major public health problem, until recently, our understanding of the risk of VTE in hospitalized acutely ill medical patients has been incomplete. Fortunately, over the past 5 years, there has been an increasing body of literature that highlights the risk of VTE in the nonsurgical patient, identifies unique patient‐risk factors, and defines adequate preventative measures. This review highlights the current literature with regard to epidemiology of VTE in hospitalized medical patients and the risk‐stratification of these patients and deals with optimal preventative regimens and prevention strategies in special patient groups. Am. J. Hematol. 79:229–237, 2005. © 2005 Wiley‐Liss, Inc.
Relationship between Thy‐1 expression and cell‐cycle distribution in human bone marrow hematopoietic progenitors
Authors: Takeda Hiroki , Yamamoto Masuji , Morita Naoko , Tanizawa Takakuni
Published: June 2005

Analysis of the relationship between Thy‐1 expression and cell‐cycle distribution of hematopoietic stem cells (HSCs) showed that freshly isolated Thy‐1+ and Thy‐1− subsets of the CD34highCD38−flt‐3−Lin− population were predominantly in G0/G1 phase and remained essentially quiescent, whereas after 6 days of cytokine stimulation, the Thy‐1+ subset of the population entered the cycling state while the Thy‐1− subset again remained quiescent. Expression of Thy‐1 antigen resulted in a drastic increase in the percentage of cycling cells in CD34highCD38‐flt‐3‐Lin‐Thy‐1+‐ as well as CD34highCD38−flt‐3−Lin− Thy‐1−‐cell‐initiated cultures. The Thy‐1+ subset of the CD34highCD38−flt‐3−Lin− population exists in the freshly isolated CD34highCD38−flt‐3−Lin− Thy‐1+ fraction, loses Thy‐1 expression during 6 days, and re‐expresses Thy‐1 for an additional 2 days. Cell‐cycle analysis demonstrated that this unique subset contains abundant S/G2M cells. Thus, Thy‐1 expression appears to be an indicator of cell‐cycle phase in targeting HSC, which might serve in the cell subset best suited for gene transfer. Am. J. Hematol. 79:187–193, 2005. © 2005 Wiley‐Liss, Inc.
Bone marrow and blood plasma levels of IL‐8 in aplastic anemia and their relationship with disease severity
Authors: Tripathy Naresh Kumar , Vibhuti  , Nityanand Soniya
Published: June 2005

Interleukin‐8 (IL‐8), a CXC chemokine, is also a potent inhibitor of myelopoiesis, the hematopoietic process that is severely impaired in aplastic anemia (AA). To elucidate its role in the disease, we have investigated levels of IL‐8 by quantitative enzyme‐linked immunosorbent assay in bone marrow and peripheral blood plasma of 27 AA patients and in the marrow of 16 controls and blood of 20 controls. Significantly increased levels of IL‐8 were observed in the marrow and blood of patients as compared to controls (470.4 ± 549.6 vs. 37.5 ± 30.3; P < 0.0001) and (247.3 ± 286.3 vs. 7.9 ± 5.5; P < 0.0001), respectively. Among the patients, the IL‐8 levels were higher in patients with severe AA than those with nonsevere AA in the marrow (568.8 ± 586.9 vs. 126.3 ± 102.5; P < 0.005) as well as in the blood (296.6 ± 305.5 vs. 75.0 ± 84.4; P < 0.008) plasma. The marrow and blood of 74% (20/27) of the patients had increased levels of IL‐8 compared to 12% (2/16; P < 0.001) and 10% (2/20, P < 0.001) of the controls, respectively. These results suggest that IL‐8 may have an important role in the pathogenesis of AA. Am. J. Hematol. 79:240–242, 2005. © 2005 Wiley‐Liss, Inc.
von Willebrand's disease and menorrhagia: Prevalence, diagnosis, and management
Authors: Kujovich Jody L.
Published: June 2005

The reported prevalence of von Willebrand's disease (vWD) is increased in women with menorrhagia, with current estimates ranging from 5% to 20%. The consistent results of multiple studies suggest testing should be included in the evaluation of patients with menorrhagia, especially in unexplained cases and prior to surgical intervention. Although a cyclic variation in von Willebrand's factor levels has not been confirmed, several studies suggest lower levels during menses and the early follicular phase. Menorrhagia is one of the most common bleeding manifestations of von Willebrand's disease, reported by 60–95% of women afflicted with this bleeding disorder. Menorrhagia is typically severe, often resulting in anemia and interfering with quality of life. Despite the frequency of menorrhagia, there is no consensus on optimal management. Although oral contraceptives are frequently prescribed, there are no studies confirming their efficacy using objective measures of response. Desmopressin was associated with an 80–92% response rate in several uncontrolled studies relying on patient assessment of efficacy. However, a small, randomized trial found no significant reduction in menstrual blood flow compared with placebo. There are anecdotal reports of the successful use of antifibrinolytic agents alone and in combination with other therapies. There are no studies comparing the relative efficacy and safety of the available medical therapies for von Willebrand's disease associated menorrhagia. Until these studies are completed, treatment should be individualized based on von Willebrand's disease subtype, patient age, contraceptive needs, and personal preference. Am. J. Hematol. 79:220–228, 2005. © 2005 Wiley‐Liss, Inc.
Fibrocongestive splenomegaly in sickle cell disease: A distinct clinicopathological entity in the Eastern province of Saudi Arabia
Authors: Chopra Rajan , Al‐Mulhim Abdul Rahman , Al‐Baharani Ahmed Taher
Published: June 2005

Sickle cell disease displays a unique progression in the Eastern province of Saudi Arabia, where splenomegaly with hypersplenism is noted with high frequency in the adolescent and adult patients. The late persistence of splenomegaly although likely reflects the milder progression of sickle cell disease in this region; nevertheless, it predisposes the patients to increased morbidity. The present study documents the characteristic clinicopathological features of splenomegaly associated with sickle cell disease in the Al‐Hassa region of Eastern province Saudi Arabia. Forty‐four cases of sickle cell disease patients in whom splenectomy was performed during 1999–2003 were studied. The hemoglobinopathy profiles of the patients (age range 5–42 years) comprised sickle cell anemia (8 cases), sickle cell anemia with high fetal hemoglobin (23 cases), and sickle cell‐β° thalassemia (13 cases). All patients had manifestations of hypersplenism and 39 patients experienced episodes of minor‐type sequestration crisis. Splenectomy was effective in ameliorating the hematological abnormalities in all cases, without any major complications in the follow‐up period. The splenectomy specimens showed moderate‐to‐marked enlargement in most cases, with histological features of fibrocongestive splenomegaly and prominent Gandy‐gamma body formations. Micro‐infarcts in 27 cases and gross infarctions in 9 cases were evident. The relationship of persistent splenomegaly with higher fetal hemoglobin levels and splenic hypofunction is examined along with the significance of splenectomy in these cases. Am. J. Hematol. 79:180–186, 2005. © 2005 Wiley‐Liss, Inc.
Thalidomide–dexamethasone as primary therapy for advanced multiple myeloma
Authors: Wang Michael , Weber Donna M. , Delasalle Kay , Alexanian Raymond
Published: June 2005

The value of thalidomide–dexamethasone was assessed in 26 consecutive, previously untreated patients with multiple myeloma of high tumor mass. All showed Hgb < 8.5 g/dL, serum calcium > 11.5 mg/dL, or both. The response rate was 73%, frequency of early death < 3 months was 5%, projected median survival was 30 months, and projected median remission time was 25 months. There were no occurrences of grade 3 or 4 neutropenia or thrombocytopenia, so that serious infection occurred in only 12% of patients. Thalidomide–dexamethasone was useful for these patients with advanced disease because of the high response rate and acceptable survival, with a low frequency of serious complications. Am. J. Hematol. 79:194–197, 2005. © 2005 Wiley‐Liss, Inc.