bluuebunny/crossref_metadata_2025 huggingface dataset:
Nucleolar Changes and Fibrillarin Redistribution Following Apatone Treatment of Human Bladder Carcinoma Cells
Authors: Jamison James M. , Gilloteaux Jacques , Perlaky Laszlo , Thiry Marc , Smetana Karel , Neal Deborah , McGuire Karen , Summers Jack L.
Published: April 2010

Ascorbate and menadione (Apatone) in a ratio of 100:1 kills tumor cells by autoschizis. In this study, vitamin-induced changes in nucleolar structure were evaluated as markers of autoschizis. Human bladder carcinoma (T24) cells were overlain with vitamins or with culture medium. Supernatants were removed at 1-hr intervals from 1 to 4 hr, and the cells were washed with PBS and prepared for assay. Apatone produced marked alterations in nucleolar structure including redistribution of nucleolar components, formation of ring-shaped nucleoli, condensation and increase of the proportion of perinucleolar chromatin, and the enlargement of nucleolar fibrillar centers. Immunogold labeling of the nucleolar rRNA revealed a granular localization in treated and sham-treated cells, and immunogold labeling of the rDNA revealed a shift from the fibrillar centers to the condensed perinucleolar chromatin. Fibrillarin staining shifted from the fibrillar centers and adjacent regions to a more homogeneous staining of the entire nucleolus and was consistent with the percentage of autoschizic cells detected by flow cytometry. Because autoschizis entails sequential reactivation of DNase I and DNase II, and because the fibrillarin redistribution following DNase I and Apatone treatment is identical, it appears that the nucleolar and fibrillarin changes are markers of autoschizis.
Small mammal survey in the upper Seli River valley, Sierra Leone
Authors: Decher Jan , Norris Ryan W. , Fahr Jakob
Published: April 2010

In 2006, an inventory of small mammals was conducted on the upper Seli River in central Sierra Leone on the southwestern fringe of the Loma-Man portion of the Guinea Highlands as part of the baseline surveys conducted for the Bumbuna Hydroelectric Project (BHP). We recorded a total of 35 mammal species, including three shrews (Soricomorpha), 19 bats (Chiroptera), 11 rodents (Rodentia), one primate, and one carnivore. New or first well-documented species for Sierra Leone are the shrew Crocidura nigeriae, the bats Myonycteris torquata, Rhinolophus denti knorri, and the rare horseshoe bat Rhinolophus ziama endemic to Upper Guinea. Also reported are two bat specimens apparently representing an undescribed species of Neoromicia related to N. nana. We support the creation of a protected area as an offset for areas lost to the inundation of the BHP reservoir.
A New Numerical Analysis for Edge Defects in Rectangular Sheet
Authors: Yan Xiangqiao , Liu Baoliang , Hu Zhaohui
Published: April 2010

This note deals with the rectangular tensile sheet with the single edge defect (crack, half-circular-hole crack and half-square-hole crack) by using the hybrid displacement discontinuity method (a boundary element method) proposed recently by Yan. Detailed solutions of the SIFs of the three plane elastic crack problems are given, which can reveal clearly the effect of geometric parameters of the cracked bodies on the SIFs. By comparing the calculated SIFs of the single edge half-circular-hole crack and the single edge half-square-hole crack with those of the single edge crack, in addition, a shielding effect of the half-circular-hole and the half-square-hole on the SIFs of the single edge crack is discussed. It is illustrated that the boundary element method is simple yet accurate for calculating the SIFs of complex crack problems in finite plate.
Effects of puberty and gonadotropins on the molecular events controlling meiotic resumption of mouse oocytes
Authors: Han Dong , Cao Xin-Yan , Wang Hui-Li , Li Jing-Jing , Wang Yan-Bo , Tan Jing-He
Published: April 2010

Although studies suggest that the low competence of oocytes from prepubertal animals is due to their insufficient cytoplasmic maturation and that FSH improves oocyte maturation possibly by retarding meiotic progression and allowing more time for cytoplasmic maturation, the mechanisms by which puberty and gonadotropins regulate meiotic progression require additional detailed studies. For the first time, we observed that while meiotic progression was significantly slower, the maturation-promoting factor (MPF) activity of oocytes was significantly higher in prepubertal than in adult mice. To resolve this contradiction, we specified the molecules regulating the MPF activity and their localization during oocyte maturation in prepubertal and adult mice primed with or without gonadotropins. Our tests using corresponding enzyme regulators suggested that while activities of protein kinase A were unaffected, the activity of adenylate cyclase (ADCY) and phosphodiesterase increased while cell division cycle 2 homolog A (CDC2A) decreased significantly after puberty. While most of the adult oocytes had CDC2A protein concentrated in the germinal vesicle (GV) region, the majority of prepubertal oocytes showed no nuclear concentration of CDC2A. Maximally priming mice with equine chorionic gonadotropin brought the above parameters of prepubertal oocytes close to those in adult oocytes. Together, the results suggest that puberty and gonadotropin control oocyte meiotic progression mainly by regulating the ADCY activity and the concentration of the activated MPF toward the GV region.
Loss of protein phosphatase 1cγ (PPP1CC) leads to impaired spermatogenesis associated with defects in chromatin condensation and acrosome development: an ultrastructural analysis
Authors: Forgione Nicole , Vogl A Wayne , Varmuza Susannah
Published: April 2010

Human male infertility affects ∼5% of men, with one-third suffering from testicular failure, likely the result of an underlying genetic abnormality that disrupts spermatogenesis during development. Mouse models of male infertility such as thePpp1ccknockout mouse display very similar phenotypes to humans with testicular failure. MalePpp1ccmutant mice are sterile due to disruptions in spermatogenesis that begin during prepubertal testicular development, and continue into adulthood, often resulting in loss of germ cells to the point of Sertoli cell-only syndrome. The current study employs light and electron microscopy to identify new morphological abnormalities inPpp1ccmutant seminiferous epithelium. This study reveals that germ cells become delayed in their development around stages VII and VIII of spermatogenesis. Loss of these cells likely results in the reduced numbers of elongating spermatids and spermatozoa previously observed in mutant animals. Interestingly,Ppp1ccmutants also display reduced numbers of spermatogonia compared with their wild-type counterparts. Using electron microscopy, we have shown that junction complexes inPpp1ccmutants are ultrastructurally normal, and therefore do not contribute to the breakdown in tissue architecture seen in mutants. Electron microscopy revealed major acrosomal and chromatin condensation defects inPpp1ccmutants. Our observations are discussed in the context of known molecular changes inPpp1ccmutant testes.
Metabolite concentrations in follicular fluid may explain differences in fertility between heifers and lactating cows
Authors: Bender K , Walsh S , Evans A C O , Fair T , Brennan L
Published: April 2010

There has been a marked decline in the fertility of dairy cows over the past decades, and metabolomic analysis offers a potential to investigate the underlying causes. Metabolite composition of the follicular fluid, which presents the intrafollicular environment, may be an important factor affecting oocyte maturation and subsequent early embryo development. The aim of the present study was to investigate the metabolic differences between follicular fluid from the dominant follicle of lactating cows and heifers using gas chromatography mass spectrometry (GC–MS)-based metabolomics. Follicular fluid and serum were collected from cows and heifers over three phases of follicle development: newly selected dominant follicles, preovulatory follicles prior to oestrus and post-LH surge follicles. Analysis of the fatty acids revealed that there were 24 fatty acids and 9 aqueous metabolites significantly different between cows and heifers. Of particular interest were the higher concentrations of saturated fatty acids (palmitic acid,P=0.001; stearic acid,P=0.005) in follicular fluid from cows and higher docosahexaenoic acid levels (P=0.022) in follicular fluid from heifers. Analysis of the metabolite composition of serum revealed that follicular fluid had a unique lipid composition. The higher concentrations of detrimental saturated fatty in cows will have a negative impact on oocyte maturation and early embryo development. Overall, the results suggest that the follicle microenvironment in cows potentially places their oocytes at a developmental disadvantage compared with heifers, and that this may contribute to well-characterised differences in fertility.
The Effect of Recent Admixture on Inference of Ancient Human Population History
Authors: Lohmueller Kirk E , Bustamante Carlos D , Clark Andrew G
Published: April 2010

Despite the widespread study of genetic variation in admixed human populations, such as African-Americans, there has not been an evaluation of the effects of recent admixture on patterns of polymorphism or inferences about population demography. These issues are particularly relevant because estimates of the timing and magnitude of population growth in Africa have differed among previous studies, some of which examined African-American individuals. Here we use simulations and single-nucleotide polymorphism (SNP) data collected through direct resequencing and genotyping to investigate these issues. We find that when estimating the current population size and magnitude of recent growth in an ancestral population using the site frequency spectrum (SFS), it is possible to obtain reasonably accurate estimates of the parameters when using samples drawn from the admixed population under certain conditions. We also show that methods for demographic inference that use haplotype patterns are more sensitive to recent admixture than are methods based on the SFS. The analysis of human genetic variation data from the Yoruba people of Ibadan, Nigeria and African-Americans supports the predictions from the simulations. Our results have important implications for the evaluation of previous population genetic studies that have considered African-American individuals as a proxy for individuals from West Africa as well as for future population genetic studies of additional admixed populations.
Distribution of Fitness Effects Caused by Single-Nucleotide Substitutions in Bacteriophage f1
Authors: Peris Joan B , Davis Paulina , Cuevas José M , Nebot Miguel R , Sanjuán Rafael
Published: April 2010

Empirical knowledge of the fitness effects of mutations is important for understanding many evolutionary processes, yet this knowledge is often hampered by several sources of measurement error and bias. Most of these problems can be solved using site-directed mutagenesis to engineer single mutations, an approach particularly suited for viruses due to their small genomes. Here, we used this technique to measure the fitness effect of 100 single-nucleotide substitutions in the bacteriophage f1, a filamentous single-strand DNA virus. We found that approximately one-fifth of all mutations are lethal. Viable ones reduced fitness by 11% on average and were accurately described by a log-normal distribution. More than 90% of synonymous substitutions were selectively neutral, while those affecting intergenic regions reduced fitness by 14% on average. Mutations leading to amino acid substitutions had an overall mean deleterious effect of 37%, which increased to 45% for those changing the amino acid polarity. Interestingly, mutations affecting early steps of the infection cycle tended to be more deleterious than those affecting late steps. Finally, we observed at least two beneficial mutations. Our results confirm that high mutational sensitivity is a general property of viruses with small genomes, including RNA and single-strand DNA viruses infecting animals, plants, and bacteria.
The Evolutionary Dynamics of Operon Distributions in Eukaryote Genomes
Authors: Cutter Asher D , Agrawal Aneil F
Published: April 2010

Genes in nematode and ascidian genomes frequently occur in operons—multiple genes sharing a common promoter to generate a polycistronic primary transcript—and such genes comprise 15–20% of the coding genome for Caenorhabditis elegans and Ciona intestinalis. Recent work in nematodes has demonstrated that the identity of genes within operons is highly conserved among species and that the unifying feature of genes within operons is that they are expressed in germline tissue. However, it is generally unknown what processes are responsible for generating the distribution of operon sizes across the genome, which are composed of up to eight genes per operon. Here we investigate several models for operon evolution to better understand their abundance, distribution of sizes, and evolutionary dynamics over time. We find that birth–death models of operon evolution reasonably describe the relative abundance of operons of different sizes in the C. elegans and Ciona genomes and generate predictions about the number of monocistronic, nonoperon genes that likely participate in the birth–death process. This theory, and applications to C. elegans and Ciona, motivates several new and testable hypotheses about eukaryote operon evolution.
A Two-Stage Approximation for Analysis of Mixture Genetic Models in Large Pedigrees
Authors: Habier D , Totir L R , Fernando R L
Published: April 2010

Information from cosegregation of marker and QTL alleles, in addition to linkage disequilibrium (LD), can improve genomic selection. Variance components linear models have been proposed for this purpose, but accommodating dominance and epistasis is not straightforward with them. A full-Bayesian analysis of a mixture genetic model is favorable in this respect, but is computationally infeasible for whole-genome analyses. Thus, we propose an approximate two-step approach that neglects information from trait phenotypes in inferring ordered genotypes and segregation indicators of markers. Quantitative trait loci (QTL) fine-mapping scenarios, using high-density markers and pedigrees of five generations without genotyped females, were simulated to test this strategy against an exact full-Bayesian approach. The latter performed better in estimating QTL genotypes, but precision of QTL location and accuracy of genomic breeding values (GEBVs) did not differ for the two methods at realistically low LD. If, however, LD was higher, the exact approach resulted in a slightly higher accuracy of GEBVs. In conclusion, the two-step approach makes mixture genetic models computationally feasible for high-density markers and large pedigrees. Furthermore, markers need to be sampled only once and results can be used for the analysis of all traits. Further research is needed to evaluate the two-step approach for complex pedigrees and to analyze alternative strategies for modeling LD between QTL and markers.
Genes Required for Cellular UNC-6/Netrin Localization in Caenorhabditis elegans
Authors: Asakura Taro , Waga Naoko , Ogura Ken-ichi , Goshima Yoshio
Published: April 2010

UNC-6/Netrin is an evolutionarily conserved, secretory axon guidance molecule. In Caenorhabditis elegans, UNC-6 provides positional information to the axons of developing neurons, probably by establishing a concentration gradient from the ventral to the dorsal side of the animal. Although the proper localization of UNC-6 is important for accurate neuronal network formation, little is known about how its localization is regulated. Here, to examine the localization mechanism for UNC-6, we generated C. elegans expressing UNC-6 tagged with the fluorescent protein Venus and identified 13 genes, which are involved in the cellular localization of Venus∷UNC-6. For example, in unc-51, unc-14, and unc-104 mutants, the neurons showed an abnormal accumulation of Venus∷UNC-6 in the cell body and less than normal level of Venus∷UNC-6 in the axon. An aberrant accumulation of Venus∷UNC-6 in muscle cells was seen in unc-18 and unc-68 mutants. unc-51, unc-14, and unc-104 mutants also showed defects in the guidance of dorso-ventral axons, suggesting that the abnormal localization of UNC-6 disturbed the positional information it provides. We propose that these genes regulate the process of UNC-6 secretion: expression, maturation, sorting, transport, or exocytosis. Our findings provide novel insight into the localization mechanism of the axon guidance molecule UNC-6/Netrin.
Distinct Regulation of Mlh1p Heterodimers in Meiosis and Mitosis in Saccharomyces cerevisiae
Authors: Cotton Victoria E , Hoffmann Eva R , Borts Rhona H
Published: April 2010

Mlh1p forms three heterodimers that are important for mismatch repair (Mlh1p/Pms1p), crossing over during meiosis (Mlh1p/Mlh3p), and channeling crossover events into a specific pathway (Mlh1p/Mlh2p). All four proteins contain highly conserved ATPase domains and Pms1p has endonuclease activity. Studies of the functional requirements for Mlh1p/Pms1p in Saccharomyces cerevisae revealed an asymmetric contribution of the ATPase domains to repairing mismatches. Here we investigate the functional requirements of the Mlh1p and Mlh3p ATPase domains in meiosis by constructing separation of function mutations in Mlh3p. These mutations are analogous to mutations of Mlh1p that have been shown to lead to loss of ATP binding and/or ATP hydrolysis. Our data suggest that ATP binding by Mlh3p is required for meiotic crossing over while ATP hydrolysis is dispensable. This has been seen previously for Mlh1p. However, when mutations that affect ATP hydrolysis by both Mlh3p and Mlh1p are combined within a single cell, meiotic crossover frequencies are reduced. These observations suggest that the function of the Mlh1p/Mlh3p heterodimer requires both subunits to bind ATP but only one to efficiently hydrolyze it. Additionally, two different amino acid substitutions to the same residue (G97) in Mlh3p affect the minor mismatch repair function of Mlh3p while only one of them compromises its ability to promote crossing over. These studies thus reveal different functional requirements among the heterodimers formed by Mlh1p.
Are Diagnostic Criteria for Eating Disorders Markers of Medical Severity?
Authors: Peebles Rebecka , Hardy Kristina K. , Wilson Jenny L. , Lock James D.
Published: April 2010

OBJECTIVE:

The objective of this study was to compare the medical severity of adolescents who had eating disorders not otherwise specified (EDNOS) with those who had anorexia nervosa (AN) and bulimia nervosa (BN).

METHODS:

Medical records of 1310 females aged 8 through 19 years and treated for AN, BN, or EDNOS were retrospectively reviewed. Patients with EDNOS were subcategorized into partial AN (pAN) and partial BN (pBN) when they met all Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria but 1 for AN or BN, respectively. Primary outcome variables were heart rate, systolic blood pressure, temperature, and QTc interval on electrocardiogram. Additional physiologically significant medical complications were also reviewed.

RESULTS:

A total of 25.2% of females had AN, 12.4% had BN, and 62.4% had EDNOS. The medical severity of patients with EDNOS was intermediate to that of patients with AN and BN in all primary outcomes. Patients with pAN had significantly higher heart rates, systolic blood pressures, and temperatures than those with AN; patients with pBN did not differ significantly from those with BN in any primary outcome variable; however, patients with pAN and pBN differed significantly from each other in all outcome variables. Patients with pBN and BN had longer QTc intervals and higher rates of additional medical complications reported at presentation than other groups.

CONCLUSIONS:

EDNOS is a medically heterogeneous category with serious physiologic sequelae in children and adolescents. Broadening AN and BN criteria in pediatric patients to include pAN and pBN may prove to be clinically useful.
Prenatal Alcohol Exposure and Neurodevelopmental Disorders in Children Adopted From Eastern Europe
Authors: Landgren Magnus , Svensson Leif , Strömland Kerstin , Andersson Grönlund Marita
Published: April 2010

OBJECTIVES:

The purposes of this investigation were to determine the frequencies of and associations between different neurodevelopmental disorders and to study the potential lasting effects of alcohol on children adopted from eastern Europe.

METHODS:

In a population-based, prospective, observational, multidisciplinary, cross-sectional, cohort study of 71 children adopted from eastern Europe, children were assessed 5 years after adoption, from pediatric, neuropsychological, and ophthalmologic perspectives.

RESULTS:

Fetal alcohol spectrum disorders, that is, fetal alcohol syndrome (FAS), partial FAS, and alcohol-related neurodevelopmental disorders, were identified for 52% of children; FAS was found for 30%, partial FAS for 14%, and alcohol-related neurodevelopmental disorders for 9%. Alcohol-related birth defects were found for 11% of children, all of whom also were diagnosed as having FAS. Mental retardation or significant cognitive impairment was found for 23% of children, autism for 9%, attention-deficit/hyperactivity disorder for 51%, and developmental coordination disorder for 34%.

CONCLUSIONS:

Fetal alcohol spectrum disorders and neurodevelopmental disorders were common in this long-term follow-up study of children adopted from orphanages in eastern Europe. Maternal alcohol consumption during pregnancy has long-lasting adverse effects, causing structural, behavioral, and cognitive damage despite a radically improved environment.
Antiretroviral Therapy Outcomes in Resource-Limited Settings for HIV-Infected Children <5 Years of Age
Authors: Sauvageot Delphine , Schaefer Myrto , Olson David , Pujades-Rodriguez Mar , O'Brien Daniel P.
Published: April 2010

OBJECTIVE:

We describe medium-term outcomes for young children receiving antiretroviral therapy (ART) in resource-limited countries.

METHODS:

Analyses were conducted on surveillance data for children <5 years of age receiving ART (initiated April 2002 to January 2008) in 48 HIV/AIDS treatment programs in Africa and Asia. Primary outcome measures were probability of remaining in care, probability of developing World Health Organization stage 4 clinical events, rate of switching to second-line ART, and drug toxicity, compared at 6, 12, 24, and 36 months of ART.

RESULTS:

Of 3936 children (90% in Africa) initiating ART, 9% were <12 months, 50% were 12 to 35 months, and 41% were 36 to 59 months of age. The median time of ART was 10.5 months. Probabilities of remaining in care after 12, 24, and 36 months of ART were 0.85, 0.80, and 0.75, respectively. Compared with children 36 to 59 months of age at ART initiation, probabilities of remaining in care were significantly lower for children <12 months of age. Overall, 55% and 69% of deaths and losses to follow-up occurred in the first 3 and 6 months of ART, respectively. Probabilities of developing stage 4 clinical events after 12, 24, and 36 months of ART were 0.03, 0.06, and 0.09, respectively. Only 33 subjects (0.8%) switched to second-line regimens, and 151 (3.8%) experienced severe drug toxicities.

CONCLUSIONS:

Large-scale ART for children <5 years of age in resource-limited settings is feasible, with encouraging clinical outcomes, but efforts should be increased to improve early HIV diagnosis and treatment.
Animated Video vs Pamphlet: Comparing the Success of Educating Parents About Proper Antibiotic Use
Authors: Schnellinger Mark , Finkelstein Marsha , Thygeson Megan V. , Vander Velden Heidi , Karpas Anna , Madhok Manu
Published: April 2010

OBJECTIVE:

The objective was to create an animated video to teach parents about the appropriate use of antibiotics and to compare their knowledge to parents who were provided with the American Academy of Pediatrics pamphlet. We hypothesized that the video format would result in improved comprehension and retention.

METHODS:

This prospective randomized, controlled trial was conducted in an urban pediatric emergency department. Parent subjects were randomly assigned to a control group, a pamphlet group, and a video group and completed a survey at 3 time points. Analysis included the nonparametric matched Friedman test, Kruskal-Wallis test, and the Mann-Whitney U test. A 2-sided P value of <.05 was required for significance, and a Bonferroni-corrected P value of <.017 was required for paired comparisons.

RESULTS:

Postintervention survey scores improved significantly in the pamphlet and video groups compared with baseline. The video group's follow-up scores were not significantly different from the postintervention-survey scores (P = .32). The pamphlet-group scores at follow-up were significantly lower than the postintervention-survey scores (P = .002). The control group's scores were similar at all 3 time periods. The pamphlet group had significantly better scores than the control group after the intervention (P < .001). The video-group scores exceeded the control-group scores at all 3 time periods.

CONCLUSIONS:

An animated video is highly effective for educating parents about the appropriate use of antibiotics in the emergency department setting and results in long-term knowledge retention. The results of this study provide a foundation to further evaluate the use of animated video in additional populations.
Unacylated ghrelin and obestatin increase islet cell mass and prevent diabetes in streptozotocin-treated newborn rats
Authors: Granata Riccarda , Volante Marco , Settanni Fabio , Gauna Carlotta , Ghé Corrado , Annunziata Marta , Deidda Barbara , Gesmundo Iacopo , Abribat Thierry , van der Lely Aart-Jan , Muccioli Giampiero , Ghigo Ezio , Papotti Mauro
Published: April 2010

The ghrelin gene products, namely acylated ghrelin (AG), unacylated ghrelin (UAG), and obestatin (Ob), were shown to prevent pancreatic β-cell death and to improve β-cell function under treatment with cytokines, which are major cause of β-cell destruction in diabetes. Moreover, AG had been described previously to prevent streptozotocin (STZ)-induced diabetes in rats; however, the effect of either UAG or Ob has never been examined in this context. In the present study, we investigated the potential of UAG and Ob to increase islet β-cell mass and to reduce diabetes at adult age in STZ-treated neonatal rats. One-day-old rats were injected with STZ and subsequently administered with either AG, UAG or Ob for 7 days. On day 70, plasma glucose levels, plasma and pancreatic insulin levels, pancreatic islet area and number, insulin and pancreatic/duodenal homeobox-1 (Pdx1) gene expression, and antiapoptotic BCL2 protein expression were determined. Similarly to AG, both UAG and Ob counteracted STZ-induced high glucose levels and improved plasma and pancreatic insulin levels, which were reduced by the diabetogenic compound. UAG and Ob increased islet area, islet number, and β-cell mass with respect to STZ treatment alone. Finally, in STZ-treated animals, UAG and Ob up-regulated insulin and Pdx1 mRNA and increased the expression of BCL2 similarly to AG. Taken together, our results suggest that in STZ-treated newborn rats, UAG and Ob improve glucose metabolism and preserve islet cell mass, granting a therapeutic potential in medical conditions associated with impaired β-cell function.
Phenotypic Variation for Diastatic Power, β‐Amylase Activity, and β‐Amylase Thermostability vs. Allelic Variation at the Bmy1 Locus in a Sample of North American Barley Germplasm
Authors: Filichkin T. P. , Vinje M. A. , Budde A. D. , Corey A. E. , Duke S. H. , Gallagher L. , Helgesson J. , Henson C. A. , Obert D. E. , Ohm J. B. , Petrie S. E. , Ross A. S. , Hayes P. M.
Published: April 2010

Malting quality data were collected on malts from three barley (Hordeum vulgare L.) breeding program trials. We tried to identify causal polymorphisms in the Bmy1 intron III and coding regions for use in marker‐assisted selection. Abundant malting quality variation exists in the spring barley germplasm despite the parents having identical Bmy1 intron III and coding regions. After complete Bmy1 sequencing, no polymorphisms associated with malting quality phenotypes, indicating the genetic basis for the observed variation resides outside Bmy1. Complete allele sequencing identified one winter barley parent that had a novel Bmy1 allele (Sd1a) based on amino acid substitutions that are candidates as causative agents for the phenotypic variation. Marker‐assisted selection against the Sd1a allele could be effective in improving diastatic power (DP). The Sd1a allele is associated with low DP and is present in only three of the 51 lines, presumably due to preceding generations being selected for high DP. Selection for DP has subsequently eliminated the Sd1a allele from this breeding program. This research shows the importance of having complete allele sequences and knowledge of functional polymorphisms in target genes before using marker‐assisted selection.
Field Evaluation of Reduced‐Growth, Glyphosate‐Resistant Kentucky Bluegrass in a Noncompetitive Setting
Authors: Blume Christopher J. , Fei Shui‐Zhang , Christians Nick E.
Published: April 2010

Reduced‐growth, glyphosate‐resistant Kentucky bluegrass (Poa pratensis L.) has recently been developed. There has been no comparative analysis of the newly developed transgenic Kentucky bluegrass lines to conventional cultivars or tissue culture‐derived lines to determine vegetative and flower characteristic differences and similarities. This study measured the vegetative and reproductive characteristics of the transgenic lines, tissue culture‐derived control lines, and reference cultivars during 2004 and 2005, in Ames, IA. The study was conducted in a noncompetitive, nonmown, spaced plant setting. Data collection of vegetative characteristics included rhizome spread and total plant area. Data collection for flower characteristics included flower phenology and morphological characteristic measurements, including panicle length, number of spikelets per panicle, and flag leaf characteristics. Transgenic lines as a group exhibited 29 and 32% less rhizome spread than the reference cultivars and tissue culture‐derived control lines, respectively, in 2004 and 37 and 40% less rhizome spread than reference cultivars and tissue culture‐derived control lines, respectively, in 2005. Flower emergence times for all transgenic lines were comparable to their respective tissue culture‐derived control lines and reference cultivars.
Competitive Ability and Phytotoxic Potential of Four Winter Canola Hybrids as Affected by Nitrogen Supply
Authors: Vasilakoglou Ioannis , Dhima Kico , Karagiannidis Nikitas , Gatsis Thomas , Petrotos Konstantinos
Published: April 2010

Low inputs in nitrogen may affect canola (Brassica napus L.) competitiveness and allelopathic potential as well as grain and oil yields. A 2‐yr study was conducted to assess nitrogen supply effect on the ability of four canola hybrids to compete with corn poppy (Papaver rhoeas L.) as well as its effect on canola seed and oil yields. Phytotoxic potential of canola hybrids on germination and growth of winter wild oat (Avena sterilis spp. ludoviciana L.), corn poppy, and wild mustard (Sinapis arvensis L.) was also determined using a perlite‐based bioassay. At canola blossom, corn poppy plant number in nitrogen‐treated plots was 23% less than that in the nitrogen‐untreated ones. Canola seed and oil yield was reduced 18.6 and 23.7%, respectively, by the competition of 100 corn poppy plants m−2, with ‘Elan’ and ‘Titan’ the most productive hybrids. Nitrogen supply did not increase in all cases the competitive ability or the seed and oil yields. In the laboratory, germination of the winter weeds was completely inhibited by the greatest extract concentration (5 g 100 mL−1) of all hybrids. Nitrogen supply did not affect, in most cases, the phytotoxicity of canola hybrids, while phytotoxicity did not significantly differ among hybrids. Conclusively, the hybrids Elan and Titan, cultivated without any herbicide or nitrogen fertilizer, could be viable as a short‐term alternative crop system for canola seed and oil production, especially in organic or low‐input fields infested by corn poppy.
Increasing Population Hybridity by Restricting Self‐Incompatibility Alleles in Red Clover Populations
Authors: Riday Heathcliffe , Krohn Andrew L.
Published: April 2010

Current red clover (Trifolium pratense L.) breeding methods for quantitative traits consist almost entirely of recurrent phenotypic selection. In many species, improved cultivars have been achieved through hybrid breeding methods, especially for highly nonadditive traits. Hybrid methods have previously been studied and developed in red clover; inbreeding depression was a hindrance to the utility of these breeding systems. In other forage legumes, population hybrids have been proposed as a way to achieve 50% hybrid seed while eliminating problems associated with inbreeding. This study proposes using gametophytic self‐incompatibility S‐locus in red clover to achieve population hybrids with 75% interpopulation hybrid seed; this would be accomplished by restricting S‐alleles to three per population. To test this concept, five S‐allele restricted populations were developed. These five restricted populations were randomly mated with a unrestricted population using bumble bees (Bombus impatiens Cresson) in five separate screened enclosures. Halfsib seed was harvested off plants for paternity testing. On average, 75% of the progeny of the five S‐allele restricted population plants were hybrids, while 48% of the progeny of the unrestricted population plants were hybrids. Observed hybridity corresponded almost perfectly with expected hybridity. This study demonstrates the feasibility of increasing hybridity by restricting S‐alleles within red clover populations.
Developing a Device to Quantify Light Penetration in Turfgrass Canopies
Authors: White R. , Steinke K. , Fontanier C. , Thomas J.
Published: April 2010

Light penetration measurements have not been possible in turfgrass environments due to the large size of commercial light bars relative to the low height of the turfgrass canopy. A light bar was designed and constructed for use in turfgrass canopies mowed as short as 1.3 cm. The instrument uses four miniature solar cells connected in parallel and mounted to a high density polyethylene (HDPE) bar measuring 3.5‐mm wide, 6‐mm tall, and 200‐mm long. The constructed light bar was calibrated against a Li‐Cor (Li‐Cor, Lincoln, NE) pyranometer sensor and obtained a relationship of Y = 1.0293e16.039x with an R2 value of 0.96. Data demonstrate measured differences in light penetration through an annual ryegrass (Lolium multiflorum Lam.) canopy maintained at three mowing heights. Light penetration measured at the base of annual ryegrass canopies maintained at cutting heights of 3.2, 5.7. and 8.3 cm amounted to 5.36 to 7.48%, 1.21 to 3.43%, and 0.10 to 0.40%, of full sunlight, respectively. This device should allow researchers the ability to assess canopy light penetration in low‐growing vegetation including turfgrasses.
Relationship of Carbohydrate and Abscisic Acid Levels to Kernel Set in Maize under Postpollination Water Deficit
Authors: Setter Tim L. , Parra Romelia
Published: April 2010

Maize (Zea mays L.) yield is substantially diminished by drought during the initial phase of kernel development. To advance our understanding of the mechanisms underlying this response, we determined the timing of sucrose, glucose, starch, and abscisic acid (ABA) accumulation in apical (inferior) and basal (superior) kernels during water deficit (3–8 d after pollination) and recovery. While net flux of material was nearly zero into both apical and basal kernels during stress, growth resumed after rewatering only in basal kernels. In bulk tissues of pedicel‐placenta, pericarp, or endosperm, basal kernels did not have higher glucose, sucrose, or starch concentrations than apical kernels. However, glucose and sucrose concentration in the pedicel–endosperm interface where phloem terminates was maintained at control concentrations in basal kernels, while it was depleted in apical kernels. Kernel set in basal versus apical kernels was also associated with lower levels of ABA in the pedicel‐placenta tissue of basal kernels after rewatering. These findings support a model of interacting influences of carbohydrate and ABA, and suggest that this interaction might be a good target for future efforts to genetically improve maize drought tolerance.
QTL Mapping of Tropical Maize Grain Components Associated with Maize Weevil Resistance
Authors: García‐Lara Silverio , Burt Andrew J. , Arnason John T. , Bergvinson David J.
Published: April 2010

The maize weevil (MW), Sitophilus zeamais (Motsch.), is a globally distributed pest that causes severe losses in stored maize (Zea mays L.) worldwide. A previous study identified quantitative trait loci (QTL) contributing to reduced grain damage and losses by MW in the maize mapping population CML290 × Muneng‐8128C0HC1‐18‐2‐1‐1. This study was conducted to identify QTL associated with the identified biochemical bases of resistance in the maize grain. Eleven traits were analyzed on grain samples from F2 lines across two environments: p‐coumaric acid (p‐CA), cis‐ and trans‐ferulic acid (FA), four isomers of diferulic acids (DiFA), phenolic acid amides (p‐coumaroyl‐feruloyl putrescine [CFP] and diferuloyl putrescine [DFP]), total DiFA and total phenols acids (PhA). Significant variations were observed for most of the traits, while heritabilities ranged from 0.09 to 0.79. Ten QTL were identified for trans‐ and cis‐FA, 8,5′‐DiFA, 8‐O‐4′‐DiFA, 8,5′‐diferulic acid benzofuran form, DFP, and CFP while seven QTL were identified for p‐CA, 5,5′‐DiFA, FA, total DiFAs, and total PhA. These QTL were dispersed across the maize genome and explain between 25 and 47% of the phenotypic variance (σ2p) and 50 to 98% of the genotypic variance (σ2g). Nine regions were common between QTL associated with MW susceptibility and cell wall bound compounds, suggesting a strong genetic association with MW resistance in tropical maize.
Comparison of the Effects of Extrusion Cooking on Some Cereal Starches
Authors: Majzoobi Mahsa , Farahnaky Asgar
Published: April 2010

The physicochemical properties of extruded starches from wheat, maize and rice were compared. These samples were extruded with a twin-screw extruder at varying water feed rates of 1.78, 1.25, 0.70, 0.35 and zero kg/h. The expansion of the samples (producing puffed products in all cases) increased with increasing the specific mechanical energy (SME). However maize flour produced the most expanded product, whilst rice samples produced the least expanded one. The cold-water viscosity of the samples at 25.0°C measured by the RVA were different; for wheat samples it decreased with increasing the SME input, for rice samples it showed a reverse relationship with the SME and for maize samples it was rising at lower SME inputs and then falling at higher SMEs. The x-ray diffraction patterns of extruded starches changed from the A-pattern" to V"- and E"- patterns. Determination of the apparent sedimentation coefficients at a constant concentration (s* value) of amylose and amylopectin of the samples showed that degradation of mainly amylopectin could occur during extrusion cooking. Differences in composition and molecular structure of these samples along with the breakdown of amylopectin may be the key factors in explaining the different physicochemical behaviors of these samples.
Intergenerational Income Mobility in a Less-Developed, High-Inequality Context: The Case of Chile
Authors: Nunez Javier I , Miranda Leslie
Published: April 2010

This paper studies the magnitude of intergenerational income mobility in less developed, high inequality Chile. Following a known methodology where fathers' incomes are predicted from standard income determinants such as education and occupation, we get comparable estimates of the intergenerational income elasticity in the range of 0.57 to 0.74 and 0.63 to 0.76 for ages 25-40 and 31-40, respectively. These values place Chile at the high end of the available international evidence. Considering Chile's high income inequality, this finding supports the hypothesis proposed in the literature of an inverse relationship between cross-sectional income inequality and intergenerational income mobility.
Collusive Behavior of Bidders in English Auctions: A Cooperative Game Theoretic Analysis
Authors: Oishi Takayuki
Published: April 2010

In practice, collusive bidders' rings in English auctions with a single object frequently distribute collusive gains among ring members via sequences of re-auctions called knockouts. The present paper introduces a model of sequences of knockouts under the situation in which each bidder has information on his evaluation and the order of the evaluations of all bidders for the object. The present paper examines the distributive function of sequences of knockouts from the viewpoint of cooperative game theory. Each sequence of knockouts yields an element of the core, two particular sequences yielding the Shapley value and the nucleolus respectively. The present paper highlights the sequence of knockouts yielding the nucleolus.
The Optimal Accuracy Level in Asymmetric Contests
Authors: Wang Zhewei
Published: April 2010

We interpret the discriminatory power, r, in the Power Contest Success Function (Tullock, 1980) as the contest designer's accuracy level. We look at the cases where two contestants are heterogeneous in ability and construct an equilibrium set for r > 0. We find that if the contestants are sufficiently different in ability, there always exists an optimal accuracy level for the contest designer. Additionally, as the difference in their abilities increases, the optimal accuracy level decreases.
Data Curation Standards and Social Science Occupational Information Resources
Authors: Lambert Paul , Gayle Vernon , Tan Larry , Turner Ken , Sinnott Richard , Prandy Ken
Published: April 2010

Occupational information resources - data about the characteristics of different occupational positions - are widely used in the social sciences, across a range of disciplines and international contexts. They are available in many formats, most often constituting small electronic files that are made freely downloadable from academic web pages. However there are several challenges associated with how occupational information resources are distributed to, and exploited by, social researchers. In this paper we describe features of occupational information resources, and indicate the role digital curation can play in exploiting them. We report upon the strategies used in the GEODE research project (Grid Enabled Occupational Data Environment1). This project attempts to develop long-term standards for the distribution of occupational information resources, by providing a standardized framework-based electronic depository for occupational information resources, and by providing a data indexing service, based on e-Science middleware, which collates occupational information resources and makes them readily accessible to non-specialist social scientists.
User Priorities for Data: Results from SUPER
Authors: Schopf Jennifer M. , Newhouse Steven
Published: April 2010

SUPER, a Study of User Priorities for e-infrastructure for Research, was a six-month effort funded by the UK e-Science Core Programme and JISC. Its aim was to inform investment in order to provide a usable, useful, and accessible e-infrastructure for all researchers and a coherent set of e-infrastructure services that would increase usage by at least a factor of ten by 2010. Through a series of unstructured face-to-face interviews with over 45 participants from 30 different projects, an online survey, together with a day-long workshop at NeSC, we have observed recurring issues relating to the provision of e-infrastructure. In this article we focus on the data-related issues identified during these interactions. We conclude with a prioritised list of future activities for research, development, and adoption in the data space.
Continuous tree-like scales
Authors: Cummings James
Published: April 2010

Answering a question raised by Luis Pereira, we show that a continuous tree-like scale can exist above a supercompact cardinal. We also show that the existence of a continuous tree-like scale at ℵω is consistent with Martin’s Maximum.
The groups of points on abelian varieties over finite fields
Authors: Rybakov Sergey
Published: April 2010

Let A be an abelian variety with commutative endomorphism algebra over a finite field k. The k-isogeny class of A is uniquely determined by a Weil polynomial f
A without multiple roots. We give a classification of the groups of k-rational points on varieties from this class in terms of Newton polygons of f
A(1 − t).
On locally finite minimal non-solvable groups
Authors: Arıkan Ahmet , Sezer Sezgin , Smith Howard
Published: April 2010

In the present work we consider infinite locally finite minimal non-solvable groups, and give certain characterizations. We also define generalizations of the centralizer to establish a result relevant to infinite locally finite minimal non-solvable groups.
Large continuum, oracles
Authors: Shelah Saharon
Published: April 2010

Our main theorem is about iterated forcing for making the continuum larger than ℵ2. We present a generalization of [2] which deal with oracles for random, (also for other cases and generalities), by replacing ℵ1,ℵ2 by λ, λ
+ (starting with λ = λ
<λ
> ℵ1). Well, we demand absolute c.c.c. So we get, e.g. the continuum is λ
+ but we can get cov(meagre) = λ and we give some applications. As in non-Cohen oracles [2], it is a “partial” countable support iteration but it is c.c.c.
Core stability of male and female football players
Authors: Nikolaidis Pantelis
Published: April 2010

Core stability of male and female football players

Study aim: To investigate into core stability measures and to establish the preliminary normal data.

Material and methods: Three groups of football players were studied: male players, members of an amateur club (Division IV; n = 20), female players, members of a Division I club (n = 28) and male adolescent club players (n = 17). They were subjected to 4 tests of core stability (muscular endurance of trunk flexors and extensors, and of left and right lateral bridge) at the beginning of the 2009/2010 season.

Results: No significant between-group differences were found for trunk flexors endurance. Female players were significantly (p<0.01) superior to both male groups with respect to trunk extensors endurance and inferior with respect to flexors-to-extensors ratio.

Conclusions: The results may have practical implications for football training and injury prevention.