WorldWideScience

Sample records for f2 segregating population

  1. Identifying Rare FHB-resistant Segregants in Intransigent Backcross and F2 Winter Wheat Populations

    Directory of Open Access Journals (Sweden)

    Anthony James Clark

    2016-03-01

    Full Text Available Fusarium head blight (FHB, caused mainly by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schwein.(Petch] in the US, is one of the most destructive diseases of wheat (Triticum aestivum L. and T. durum L.. Infected grain is usually contaminated with deoxynivalenol (DON, a serious mycotoxin. The challenge in FHB resistance breeding is combining resistance with superior agronomic and quality characteristics. Exotic QTL are widely used to improve FHB resistance. Success depends on the genetic background into which the QTL are introgressed, whether through backcrossing or forward crossing; QTL expression is impossible to predict. In this study four high-yielding soft red winter wheat breeding lines with little or no scab resistance were each crossed to a donor parent (VA01W-476 with resistance alleles at two QTL: Fhb1 (chromosome 3BS and QFhs.nau-2DL (chromosome 2DL to generate backcross and F2 progeny. F2 individuals were genotyped and assigned to 4 groups according to presence/ absence of resistance alleles at one or both QTL. The effectiveness of these QTL in reducing FHB rating, incidence, index, severity, Fusarium-damaged kernels (FDK and DON, in F2-derived lines was assessed over two years. Fhb1 showed an average reduction in DON of 17.5%, and conferred significant resistance in 3 of 4 populations. QFhs.nau-2DL reduced DON 6.7 % on average and conferred significant resistance in 2 of 4 populations. The combination of Fhb1 and QFhs.nau-2DL resistance reduced DON 25.5% across all populations. Double resistant lines had significantly reduced DON compared to double susceptible lines in 3 populations. Backcross derived progeny were planted in replicated yield trials (2011 and 2012 and in a scab nursery in 2012. Several top yielding lines performed well in the scab nursery, with acceptable DON concentrations, even though the average effect of either QTL in this population was not significant. Population selection is often viewed as an all

  2. Phenotypic and molecular characterization of a tomato (Solanum lycopersicum L.) F2 population segregation for improving shelf life.

    Science.gov (United States)

    Yogendra, K N; Ramanjini Gowda, P H

    2013-02-27

    Breeding for better quality fruits is a major focus for tomatoes, which are continuously subjected to post-harvest losses. Several methods have been used to improve the fruit shelf life of tomatoes, including the use of ripening gene mutants of Solanum lycopersicum. We developed extended shelf-life tomato hybrids with better quality fruits using ripening mutants. Nine tomato crosses were developed using 3 fruit ripening gene mutants of S. lycopersicum [alcobaca (alc), non-ripening, and ripening inhibitor] and 3 agronomically superior Indian cultivars ('Sankranti', 'Vaibhav', and 'Pusaruby') with short shelf life. The hybrid progenies developed from alc x 'Vaibhav' had the highest extended shelf life (up to 40 days) compared with that of other varieties and hybrids. Further, the F(2) progenies of alc x 'Vaibhav' were evaluated for fruit quality traits and yield parameters. A wide range of genetic variability was observed in shelf life (5-106 days) and fruit firmness (0.55-10.65 lbs/cm(2)). The potential polymorphic simple sequence repeat markers underlying shelf life traits were identified in an F(2) mapping population. The marker association with fruit quality traits and yield was confirmed with single-marker analysis and composite interval mapping. The genetic parameters analyzed in the parents and F(1) and F(2) populations indicated that the cross between the cultivar 'Vaibhav' and ripening gene mutant alc yielded fruit with long shelf life and good quality.

  3. Optimization of a Reaction System of Sequence Related Amplified Polymorphism and Segregation of Polymorphic Loci in an F2 Population of Rice

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An effective PCR protocol for detecting the sequence related amplified polymorphism (SRAP) in rice was developed.One hundred and ten pairs of SRAP primers were used for segregation analysis in an F2 population derived from a cross between Shennong 606 and Lijiangxintuanheigu.Among the 110 primer pairs,35 pairs generated 143 polymorphic bands with an average of 4.09 polymorphic bands per primer pair,and 24 pairs (16.78%) showed the genetic distortion (P<0.05).Of the 24 primer pairs,12 pairs deviated toward the male parent Shennong 606 and 11 pairs toward the female parent Lijiangxintuanheigu,only one toward heterozygote.It was found that the segregation distortion might be caused by the joint gametic and zygotic effects.

  4. Genetic analysis of F2 and transgressive segregants for seed yield in safflower (Carthamus tinctorius L.

    Directory of Open Access Journals (Sweden)

    D.Shivani, Ch. Sreelakshmi and C.V. Sameer Kumar

    2011-06-01

    Full Text Available The wide range of F2 variability for seed yield, number of capitula per plant and number of seeds per capitulum in 24 crosses ofline x tester set indicated potential of the crosses to throw large number of variable segregants. Maximum number of positivetransgressive segregants was found in TSF-1 x SFS 9920, TSF-1 x SSF 658, TSF-2 x ASD-07-10, Sagarmutyalu x SFS 9920andManjira x SSF 698 crosses. F1 per se performance, relative heterosis, D2 and GCA effects of parents were found to be goodindicators for predicting the phenotypic variance and genetic advance for seed yield in F2. Average GCA effects of parents hadmoderate degree of influence on the mean of 10% top yielding plants in F2.

  5. The Statistical Power of Inclusive Composite Interval Mapping in Detecting Digenic Epistasis Showing Common F2 Segregation Ratios

    Institute of Scientific and Technical Information of China (English)

    Luyan Zhang; Huihui Li; Jiankang Wang

    2012-01-01

    Epistasis is a commonly observed genetic phenomenon and an important source of variation of complex traits,which could maintain additive variance and therefore assure the long-term genetic gain in breeding.Inclusive composite interval mapping (ICIM) is able to identify epistatic quantitative trait loci (QTLs) no matter whether the two interacting QTLs have any additive effects.In this article,we conducted a simulation study to evaluate detection power and false discovery rate (FDR) of ICIM epistatic mapping,by considering F2 and doubled haploid (DH) populations,different F2 segregation ratios and population sizes.Results indicated that estimations of QTL locations and effects were unbiased,and the detection power of epistatic mapping was largely affected by population size,heritability of epistasis,and the amount and distribution of genetic effects.When the same likelihood of odd (LOD) threshold was used,detection power of QTL was higher in F2 population than power in DH population; meanwhile FDR in F2 was also higher than that in DH.The increase of marker density from 10 cM to 5 cM led to similar detection power but higher FDR.In simulated populations,ICIM achieved better mapping results than multiple interval mapping (MIM) in estimation of QTL positions and effect.At the end,we gave epistatic mapping results of ICIM in one actual population in rice (Oryza sativa L.).

  6. Variability and Character Association in F2 Segregating Population ...

    African Journals Online (AJOL)

    Michael Horsfall

    selection criteria to reduce indirect effect of the other characters during the development of high yielding tomato variety. @ JASEM ... tomato cultivars contain <5% of the genetic variation ... 1997). Considering all the facts described above the.

  7. Segregation of Species-Specific Male Attractiveness in F2 Hybrid Lake Malawi Cichlid Fish

    Directory of Open Access Journals (Sweden)

    Ola Svensson

    2011-01-01

    Full Text Available Among the huge radiations of haplochromine cichlid fish in Lakes Malawi and Victoria, closely related species are often reproductively isolated via female mate choice although viable fertile hybrids can be produced when females are confined only with heterospecific males. We generated F2 hybrid males from a cross between a pair of closely related sympatric cichlid fish from Lake Malawi. Laboratory mate choice experiments using microsatellite paternity analysis demonstrated that F2 hybrid males differed significantly in their attractiveness to females of the two parental species, indicating heritable variation in traits involved in mate choice that may contribute to reproductive isolation between these species. We found no significant correlation between male mating success and any measurement of male colour pattern. A simple quantitative genetic model of reproductive isolation suggests that there may be as few as two chromosomal regions controlling species-specific attractiveness. We propose that adaptive radiation of Lake Malawi cichlids could be facilitated by the presence of genes with major effects on mate choice and reproductive isolation.

  8. Tagging of Brown Planthopper Resistance Genes in F2s of IR50 × Ptb33 of Rice by Using Bulked Segregant Analysis

    Institute of Scientific and Technical Information of China (English)

    Venkateswarlu YADAVALLI; Gajendra P. NARWANE; M. S. R. KRISHNA; Nagarajan POTHI; Bharathi MUTHUSAMY

    2012-01-01

    Brown planthopper (Nilaparvata lugens Stǎl) is one of the most damaging pests causing hopper burn in rice,and thereby reducing the productivity and also the quality of the product.The effective management strategy to control this pest is the identification and transfer of desirable genes to local rice cultivars.The most important approach for developing resistant cultivars is the identification of markers,which can help in marker-assisted selection of more durable resistant genotype.The susceptible parent IR50 and the resistant parent Ptb33,and their F2 populations were used in bulked segregant analysis for identification of resistant genes with random amplified polymorphic DNA marker (RAPD) primers.The primers OPC7 and OPAG14 showed both dominant and susceptible specific banding pattern so called co-dominant markers.Moreover,OPC7697 and OPAG14660 showed resistant specific bands and thus being in coupling phase,whereas OPC7846 and OPAG14650 showed susceptible specific genotypic bands in bulked segregant analysis.Therefore,the coupling phase markers,OPC7697 and OPAG14680.are considered to be more useful in marker-assisted selection of rice genotypes in crop improvement.

  9. Phenotypic variation of F1 and F2 populations from three species of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... Phenotypic variation of F1 and F2 populations from ... Key words: Solanum, genome, phenotype, taxonomy, evolution, interspecific hybridization, pollen viability, ..... This development affirms the views of .... The origins of.

  10. Quantitative trait locus affecting birth weight on bovine chromosome 5 in a F2 Gyr x Holstein population

    Directory of Open Access Journals (Sweden)

    Gustavo Gasparin

    2005-12-01

    Full Text Available Segregation between a genetic marker and a locus influencing a quantitative trait in a well delineated population is the basis for success in mapping quantitative trait loci (QTL. To detect bovine chromosome 5 (BTA5 birth weight QTL we genotyped 294 F2 Gyr (Bos indicus x Holstein (Bos taurus crossbreed cattle for five microsatellite markers. A linkage map was constructed for the markers and an interval analysis for the presence of QTL was performed. The linkage map indicated differences in the order of two markers relative to the reference map (http://www.marc.usda.gov. Interval analysis detected a QTL controlling birth weight (p < 0.01 at 69 centimorgans (cM from the most centromeric marker with an effect of 0.32 phenotypic standard-error. These results support other studies with crossbred Bos taurus x Bos indicus populations.

  11. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    DEFF Research Database (Denmark)

    Tomaszewski, Céline; Byrne, Stephen; Foito, Alexandra;

    2012-01-01

    T markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used...

  12. Mapping of imprinted quantitative trait loci using immortalized F2 populations.

    Directory of Open Access Journals (Sweden)

    Yongxian Wen

    Full Text Available Mapping of imprinted quantitative trait loci (iQTLs is helpful for understanding the effects of genomic imprinting on complex traits in animals and plants. At present, the experimental designs and corresponding statistical methods having been proposed for iQTL mapping are all based on temporary populations including F2 and BC1, which can be used only once and suffer some other shortcomings respectively. In this paper, we propose a framework for iQTL mapping, including methods of interval mapping (IM and composite interval mapping (CIM based on conventional low-density genetic maps and point mapping (PM and composite point mapping (CPM based on ultrahigh-density genetic maps, using an immortalized F2 (imF2 population generated by random crosses between recombinant inbred lines or doubled haploid lines. We demonstrate by simulations that imF2 populations are very desirable and the proposed statistical methods (especially CIM and CPM are very powerful for iQTL mapping, with which the imprinting effects as well as the additive and dominance effects of iQTLs can be unbiasedly estimated.

  13. Early selection of agronomic traits in segregating black bean populations

    Directory of Open Access Journals (Sweden)

    Juliano Garcia Bertoldo

    2010-01-01

    Full Text Available This study evaluated the agronomic performance of six segregating populations of black bean (BRS Supremo x CHP 97-01, BRS Supremo x CHP 97-04, BRS Supremo x CHP 97-05-16, BRS Supremo x CHP 97-26, BRS Supremo x IPR Graúna and BRS Supremo x Uirapuru IPR in the F3 generation, conducted by the bulk method. Populations and parents were evaluated in the 2007/08 growing season in a randomized block design with four replications. Results show promising traits of the segregating population BRS Supremo x CHP 97-04, which was superior to parent BRS Supremo, indicating the line for further selection. The segregating populations and their parents were grouped by Ward’s method, indicating the similarity of the selected lines.

  14. Evidence of variation in segregation patterns within a Cedrus population.

    Science.gov (United States)

    Fallour, D; Fady, B; Lefèvre, F

    2001-01-01

    We used horizontal starch-gel electrophoresis for a genetic analysis of isozymes within one French Cedrus atlantica stand. Eleven to 29 megagametophytes per tree from 186 trees were assayed. Among the 33 enzyme systems tested, 15 correctly resolved and 8 appeared variable in at least one zone of activity: ACP, GOT, IDH, LAP, MDH, MNR, PGI, and SKDH. They were coded by at least 12 polymorphic loci which were described and tested for Mendelian segregation and linkage. Segregation patterns and linkage relationships were variable in the population. We detected homogeneous segregation distortion for loci Idh, Acp-c, and Got-a over the whole set of segregating progeny. We also found segregation distortions in a significant proportion of progeny for loci Got-b, Mdh-c, Pgi-b, and SKDH: The Acp-c and Got-b loci were linked with an overall map distance of 17 cM, but distance varied drastically among progeny. Both segregation distortions and heterogeneity of recombination frequencies indicate the occurrence of a genetic load in this population.

  15. QTL mapping for test weight by using F2:3 population in maize

    Indian Academy of Sciences (India)

    Jun-Qiang Ding; Jin-Liang Ma; Chun-Rong Zhang; Hua-Fang Dong; Zhang-Ying Xi; Zong-Liang Xia; Jian-Yu Wu

    2011-04-01

    Test weight is an important trait in maize breeding. Understanding the genetic mechanism of test weight is important for effective selection of maize test weight improvement. In this study, quantitative trait loci (QTL) for maize test weight were identified. In the years 2007 and 2008, a F2:3 population along with the parents Chang7-2 and Zheng58 were planted in Zhengzhou, People’s Republic of China. Significant genotypic variation for maize test weight was observed in both years. Based on the genetic map containing 180 polymorphic SSR markers with an average linkage distance of 11.0 cM, QTL for maize test weight were analysed by mixed-model composite interval mapping. Five QTL, including four QTL with only additive effects, were identified on chromosomes 1, 2, 3, 4 and 5, and together explained 25.2% of the phenotypic variation. Seven pairs of epistatic interactions were also detected, involving 11 loci distributed on chromosomes 1, 2, 3, 4, 5 and 7, respectively, which totally contributed 18.2% of the phenotypic variation. However, no significant QTL × environment (Q×E) interaction and epistasis × environment interaction effects were detected. The results showed that besides the additive QTL, epistatic interactions also formed an important genetic basis for test weight in maize.

  16. Interethnic variability of CYP4F2 (V433M) in admixed population of Roma and Hungarians.

    Science.gov (United States)

    Sipeky, Csilla; Weber, Agnes; Melegh, Bela I; Matyas, Petra; Janicsek, Ingrid; Szalai, Renata; Szabo, Istvan; Varnai, Reka; Tarlos, Greta; Ganczer, Alma; Melegh, Bela

    2015-07-01

    Pharmacogenetic based dosing recommendations are provided in FDA-approved warfarin label for Caucasians. Evidence of notable difference in dosing algorithms of under-represented populations forced us to explore the genetic variability of CYP4F2 gene in Roma and Hungarian populations. 484 Roma, 493 Hungarian untreated subjects were genotyped for the CYP4F2*3 (rs2108622) variant by PCR-RFLP assay. We firstly report, that frequencies of the CYP4F2 rs2108622 GG, GA, AA genotypes and A allele in the Roma population were 46.5%, 42.6%, 10.9% and 32.2%; in Hungarians 50.1%, 42.2%, 7.7% and 22.8%, respectively. Bearing of two minor alleles of CYP4F2 missense variant (AA genotype) modestly explains inter-ethnic differences of studied populations (pRoma (0.32) was in higher range, and of Hungarians (0.23) in lower range, as compared with other world populations. Roma have an elevated chance for higher mean warfarin dose, besides a decreased risk of major bleeding events in long-term warfarin use. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Parameters in the estimation of the most suitable F2 population size in conventional maize (Zea mays L. breeding programs

    Directory of Open Access Journals (Sweden)

    Delić Nenad

    2010-01-01

    Full Text Available The objective of the present study was to observe differences among four sizes of the F2 populations (100, 200, 300 and 500 plants on the basis of test-crosses for grain yield according to the average values of the populations, genetic and phenotypic variances, genotypic and phenotypic coefficients of variations and broad-sense heritability. The values of genetic variance did not significantly differ over population sizes according to all possible comparisons, including the comparison of values obtained for the phenotypic variance. Furthermore, the values of broadsense heritability (67.8%-69% did not significantly vary over different F2 population sizes. Genetic variability of the observed progenies, as a principal prerequisite of successful selection, was at the satisfactory level in all population sizes.

  18. QTL analysis of Kernel-related traits in maize using an immortalized F2 population.

    Science.gov (United States)

    Zhang, Zhanhui; Liu, Zonghua; Hu, Yanmin; Li, Weihua; Fu, Zhiyuan; Ding, Dong; Li, Haochuan; Qiao, Mengmeng; Tang, Jihua

    2014-01-01

    Kernel size and weight are important determinants of grain yield in maize. In this study, multivariate conditional and unconditional quantitative trait loci (QTL), and digenic epistatic analyses were utilized in order to elucidate the genetic basis for these kernel-related traits. Five kernel-related traits, including kernel weight (KW), volume (KV), length (KL), thickness (KT), and width (KWI), were collected from an immortalized F2 (IF2) maize population comprising of 243 crosses performed at two separate locations over a span of two years. A total of 54 unconditional main QTL for these five kernel-related traits were identified, many of which were clustered in chromosomal bins 6.04-6.06, 7.02-7.03, and 10.06-10.07. In addition, qKL3, qKWI6, qKV10a, qKV10b, qKW10a, and qKW7a were detected across multiple environments. Sixteen main QTL were identified for KW conditioned on the other four kernel traits (KL, KWI, KT, and KV). Thirteen main QTL were identified for KV conditioned on three kernel-shape traits. Conditional mapping analysis revealed that KWI and KV had the strongest influence on KW at the individual QTL level, followed by KT, and then KL; KV was mostly strongly influenced by KT, followed by KWI, and was least impacted by KL. Digenic epistatic analysis identified 18 digenic interactions involving 34 loci over the entire genome. However, only a small proportion of them were identical to the main QTL we detected. Additionally, conditional digenic epistatic analysis revealed that the digenic epistasis for KW and KV were entirely determined by their constituent traits. The main QTL identified in this study for determining kernel-related traits with high broad-sense heritability may play important roles during kernel development. Furthermore, digenic interactions were shown to exert relatively large effects on KL (the highest AA and DD effects were 4.6% and 6.7%, respectively) and KT (the highest AA effects were 4.3%).

  19. Reconstruction of linkage maps in the distorted segregation populations of backcross,doubled haploid and recombinant inbred lines

    Institute of Scientific and Technical Information of China (English)

    ZHU ChengSong; WANG FuHua; WANG JianFei; LI GuangJun; ZHANG HongSheng; ZHANG YuanMing

    2007-01-01

    Non-Mendelian segregation of markers,known as distorted segregation,is a common biological phenomenon.Although segregation distortion affects the estimation of map distances and the results of quantitative trait loci(QTL)mapping,the effects of distorted markers are often ignored in the construction of linkage maps and in QTL mapping.Recently,we have developed a multipoint method via a Hidden Markov chain method to reconstruct linkage maps in an F2 population that corrects for bias of map distances between distorted markers.In this article,the method is extended to cover backcross,doubled haploid and recombinant inbred line(RIL)populations.The results from simulated experiments show that:(1)the degree that two linked segregation distortion loci(SDL)affect the estimation of map distances increases as SDL heritability and interval length between adjacent markers increase,whereas sample size has little effect on the bias;(2)two linked SDL result in the underestimation of linkage distances for most cases,overestimation for an additive model with opposite additive effects,and unbiased estimation for an epistatic model with negative additive-by-additive effects;(3)the proposed method can obtain the unbiased estimation of linkage distance.This new method was applied to a rice RIL population with severely distorted segregation to reconstruct the linkage maps,and a bootstrap method was used to Obtain 95% confidence intervals of map distances.The results from real data analysis further demonstrate the utility of our method,which provides a foundation for the inheritance analysis of quantitative and viability traits.

  20. Determination of the optimal number of markers and individuals in a training population necessary for maximum prediction accuracy in F2 populations by using genomic selection models.

    Science.gov (United States)

    Peixoto, L A; Bhering, L L; Cruz, C D

    2016-11-21

    Genomic selection is a useful technique to assist breeders in selecting the best genotypes accurately. Phenotypic selection in the F2 generation presents with low accuracy as each genotype is represented by one individual; thus, genomic selection can increase selection accuracy at this stage of the breeding program. This study aimed to establish the optimal number of individuals required to compose the training population and to establish the amount of markers necessary to obtain the maximum accuracy by genomic selection methods in F2 populations. F2 populations with 1000 individuals were simulated, and six traits were simulated with different heritability values (5, 20, 40, 60, 80 and 99%). Ridge regression best linear unbiased prediction was used in all analyses. Genomic selection models were set by varying the number of individuals in the training population (2 to 1000 individuals) and markers (2 to 3060 markers). Phenotypic accuracy, genotypic accuracy, genetic variance, residual variance, and heritability were evaluated. Greater the number of individuals in the training population, higher was the accuracy; the values of genotypic and residual variances and heritability were close to the optimum value. Higher the heritability of the trait, higher is the number of markers necessary to obtain maximum accuracy, ranging from 200 for the trait with 5% heritability to 900 for the trait with 99% heritability. Therefore, genomic selection models for prediction in F2 populations must consist of 200 to 900 markers of major effect on the trait and more than 600 individuals in the training population.

  1. Application of alternative models to identify QTL for growth traits in an F2 Duroc x Pietrain pig resource population

    Directory of Open Access Journals (Sweden)

    Rumph Janice M

    2010-11-01

    Full Text Available Abstract Background A variety of analysis approaches have been applied to detect quantitative trait loci (QTL in experimental populations. The initial genome scan of our Duroc x Pietrain F2 resource population included 510 F2 animals genotyped with 124 microsatellite markers and analyzed using a line-cross model. For the second scan, 20 additional markers on 9 chromosomes were genotyped for 954 F2 animals and 20 markers used in the first scan were genotyped for 444 additional F2 animals. Three least-squares Mendelian models for QTL analysis were applied for the second scan: a line-cross model, a half-sib model, and a combined line-cross and half-sib model. Results In total, 26 QTL using the line-cross model, 12 QTL using the half-sib model and 3 additional QTL using the combined line-cross and half-sib model were detected for growth traits with a 5% false discovery rate (FDR significance level. In the line-cross analysis, highly significant QTL for fat deposition at 10-, 13-, 16-, 19-, and 22-wk of age were detected on SSC6. In the half-sib analysis, a QTL for loin muscle area at 19-wk of age was detected on SSC7 and QTL for 10th-rib backfat at 19- and 22-wk of age were detected on SSC15. Conclusions Additional markers and animals contributed to reduce the confidence intervals and increase the test statistics for QTL detection. Different models allowed detection of new QTL which indicated differing frequencies for alternative alleles in parental breeds.

  2. Elevated genetic diversity in an F2:6 population of quinoa (Chenopodium quinoa developed through an inter-ecotype cross

    Directory of Open Access Journals (Sweden)

    Ouafae Benlhabib

    2016-08-01

    Full Text Available Quinoa (Chenopodium quinoa is a seed crop of the Andean highlands and Araucanian coastal regions of South America that has recently expanded in use and production beyond its native range. This is largely due its superb nutritional value, consisting of protein that is rich in essential amino acids along with vitamins and minerals. Quinoa also presents a remarkable degree of tolerance to saline conditions, drought, and frost. The present study involved 72 F2:6 recombinant inbred lines (RIL and parents developed through hybridization between highland (0654 and coastal (NL-6 germplasm groups. The purpose was to characterize the quinoa germplasm developed, to assess the discriminating potential of 21 agro-morpho phenological traits, and to evaluate the extent of genetic variability recovered through selfing. A vast amount of genetic variation was detected among the 72 lines evaluated for quantitative and qualitative traits. Impressive transgressive segregation was measured for seed yield (22.42 g/plant, while plant height and maturity had higher heritabilities (73 and 89%, respectively. Other notable characters segregating in the population included panicle and stem color, panicle form, and resistance to downy mildew. In the Principal Component analysis, the first axis explained 74% of the total variation and was correlated to plant height, panicle size, stem diameter, biomass, mildew reaction, maturation, and seed yield; those traits are relevant discriminatory characters. Yield correlated positively with panicle length and biomass. UPGMA based cluster analysis identified three groups: one consisting of late, mildew-resistant, high yielding lines; one having semi-late lines with intermediate yield and mildew susceptibility; and a third cluster consisting of early to semi-late accessions with low yield and mildew susceptibility. This study highlighted the extended diversity regenerated among the 72 accessions and helped to identify potentially

  3. Elevated Genetic Diversity in an F2:6 Population of Quinoa (Chenopodium quinoa) Developed through an Inter-ecotype Cross.

    Science.gov (United States)

    Benlhabib, Ouafae; Boujartani, Noura; Maughan, Peter J; Jacobsen, Sven E; Jellen, Eric N

    2016-01-01

    Quinoa (Chenopodium quinoa) is a seed crop of the Andean highlands and Araucanian coastal regions of South America that has recently expanded in use and production beyond its native range. This is largely due to its superb nutritional value, consisting of protein that is rich in essential amino acids along with vitamins and minerals. Quinoa also presents a remarkable degree of tolerance to saline conditions, drought, and frost. The present study involved 72 F2:6 recombinant-inbred lines and parents developed through hybridization between highland (0654) and coastal (NL-6) germplasm groups. The purpose was to characterize the quinoa germplasm developed, to assess the discriminating potential of 21 agro-morpho-phenological traits, and to evaluate the extent of genetic variability recovered through selfing. A vast amount of genetic variation was detected among the 72 lines evaluated for quantitative and qualitative traits. Impressive transgressive segregation was measured for seed yield (22.42 g/plant), while plant height and maturity had higher heritabilities (73 and 89%, respectively). Other notable characters segregating in the population included panicle and stem color, panicle form, and resistance to downy mildew. In the Principal Component analysis, the first axis explained 74% of the total variation and was correlated to plant height, panicle size, stem diameter, biomass, mildew reaction, maturation, and seed yield; those traits are relevant discriminatory characters. Yield correlated positively with panicle length and biomass. Unweighted Pair Group Method with Arithmetic Mean-based cluster analysis identified three groups: one consisting of late, mildew-resistant, high-yielding lines; one having semi-late lines with intermediate yield and mildew susceptibility; and a third cluster consisting of early to semi-late accessions with low yield and mildew susceptibility. This study highlighted the extended diversity regenerated among the 72 accessions and helped to

  4. Detection of quantitative trait loci and heterotic loci for plant height using an immortalized F2 population in maize

    Institute of Scientific and Technical Information of China (English)

    TANG JiHua; MA XiQing; TENG WenTao; YAN JianBing; WU WeiRen; DAI JingRui; LI JianSheng

    2007-01-01

    A set of recombinant inbred lines (RIL) derived from Yuyu22, an elite hybrid widespread in China, was used to construct an immortalized F2 (IF2) population comprising 441 different crosses. Genetic linkage maps were constructed containing 10 linkages groups with 263 simple sequence repeat (SSR) molecular markers. Twelve and ten quantitative trait loci (QTL) were detected for plant height in the IF2 and RIL populations respectively, using the composite interval mapping method, and six same QTL were identified in the two populations. In addition, ten unique heterotic loci (HL) located on seven different chromosomes were revealed for plant height using the mid-parent heterosis as the input data. These HL explained 1.26%-8.41% of the genotypic variance in plant height heterosis and most expressed overdominant effects. Only three QTL and HL were located in the same chromosomal region, it implied that plant height and its heterosis might be controlled by two types of genetic mechanisms.

  5. The sorry state of F2 hybrids: consequences of rapid mitochondrial DNA evolution in allopatric populations.

    Science.gov (United States)

    Burton, R S; Ellison, C K; Harrison, J S

    2006-12-01

    Through the processes of natural selection and genetic drift, allopatric populations diverge genetically and may ultimately become reproductively incompatible. In cases of prezygotic reproductive isolation, candidate systems for speciation genes logically include genes involved in mate or gamete recognition. However, where only postzygotic isolation exists, candidate speciation genes could include any genes that affect hybrid performance. We hypothesize that because mitochondrial genes frequently evolve more rapidly than the nuclear genes with which they interact, interpopulation hybridization might be particularly disruptive to mitochondrial function. Understanding the potential impact of intergenomic (nuclear and mitochondrial) coadaptation on the evolution of allopatric populations of the intertidal copepod Tigriopus californicus has required a broadly integrative research program; here we present the results of experiments spanning the spectrum of biological organization in order to demonstrate the consequences of molecular evolution on physiological performance and organismal fitness. We suggest that disruption of mitochondrial function, known to result in a diverse set of human diseases, may frequently underlie reduced fitness in interpopulation and interspecies hybrids in animals.

  6. 陆地棉永久 F2群体产量、杂种优势及相关关系分析%Analysis of yield, heterosis and their correlation of cotton immortalized F2 population

    Institute of Scientific and Technical Information of China (English)

    王保勤; 李宾; 李俊文; 刘书梅; 贾新合

    2016-01-01

    利用重组自交系RIL群体两两随机组配构建1套含98个组合的永久F2群体。通过对永久群体7个性状的杂种优势表现及其性状之间的相关性进行分析,探讨永久F2群体经济性状关系。结果表明,永久F2群体的7个性状在2年3点3个不同环境下均具有明显的杂种优势,中亲优势和优势组合率较大;产量构成因子的相关系数中铃重最大,其次是单株结铃数和衣分;永久群体的竞争优势为负向,理论上此永久F2群体不能在生产上直接利用来作为杂交亲本,但可以作为遗传群体的研究材料。%In order to analyse the heterosis of yield and traits of cotton , a set of recombinant inbred line ( RIL) de-rived from a hybrid combination ( sGK9708 × 0-153 ) was used to constructed an immortalized F 2 ( IF2 ) popula-tion.This IF2 population included 98 single crosses.The heterosis analysis of seven yield traits and their correlation of immortalized F2 population was studied .The results showed that this seven traits had obvious heterosis in different environments , middle parents advantage and advantage combination rate were both larger .In the correlation factors of production , boll weight was the greatest , followed by the boll number per plant and lint percentage .Permanent group competitive advantage was negative , so this immortalized F2 population could not be directly used theoretically in pro-duction, but it could be used as genetic group research materials .

  7. Comparative QTL analysis of maize seed artificial aging between an immortalized F2 population and its corresponding RILs

    Institute of Scientific and Technical Information of China (English)

    Bin Wang; Zhanhui Zhang; Zhiyuan Fu; Zonghua Liu; Yanmin Hu; Jihua Tang

    2016-01-01

    Seed aging decreases the quality and vigor of crop seeds, thereby causing substantial agricultural and economic losses in crops. To identify genetic differences in seed aging between homozygotes and heterozygotes in maize, the seeds of a set of recombinant inbred lines (RILs) and an immortalized F2 (IF2) population were subjected to artificial aging treatments for 0, 2, 3, and 4 days under 45 ºC and 85%relative humidity and seed vigor was then evaluated in a field experiment. Seed vigor of all entries tested decreased sharply with longer aging treatment and seed vigor decreased more slowly in heterozygotes than in homozygotes. Forty-nine QTL were detected for four measured seed vigor traits in the RIL (28 QTL) and IF2 (21 QTL) populations. Only one QTL, qGP5, was detected in both populations, indicating that the genes involved in anti-aging mechanisms differed between inbred lines and hybrids. Several QTL were identified to be responsible for multiple seed vigor traits simultaneously in the RIL and IF2 populations under artificial aging conditions. These QTL may include major genes for seed vigor or seed aging. QTL qVI4b and qGE3a detected in the RIL population coincided with genes ZmLOX1 and ZmPLD1 in the same respective chromosomal regions. These QTL would be useful for screening for anti-aging genes in maize breeding.

  8. Comparative QTL analysis of maize seed artificial aging between an immortalized F2 population and its corresponding RILs

    Institute of Scientific and Technical Information of China (English)

    Bin Wang; Zhanhui Zhang; Zhiyuan Fu; Zonghua Liu; Yanmin Hu; Jihua Tang

    2016-01-01

    Seed aging decreases the quality and vigor of crop seeds,thereby causing substantial agricultural and economic losses in crops.To identify genetic differences in seed aging between homozygotes and heterozygotes in maize,the seeds of a set of recombinant inbred lines(RILs) and an immortalized F2(IF2) population were subjected to artificial aging treatments for 0,2,3,and 4 days under 45℃ and 85%relative humidity and seed vigor was then evaluated in a field experiment.Seed vigor of all entries tested decreased sharply with longer aging treatment and seed vigor decreased more slowly in heterozygotes than in homozygotes.Forty-nine QTL were detected for four measured seed vigor traits in the RIL(28QTL) and IF2(21 QTL) populations.Only one QTL,qGP5,was detected in both populations,indicating that the genes involved in anti-aging mechanisms differed between inbred lines and hybrids.Several QTL were identified to be responsible for multiple seed vigor traits simultaneously in the RIL and IF2 populations under artificial aging conditions.These QTL may include major genes for seed vigor or seed aging.QTL qVI4 b and qGE3 a detected in the RIL population coincided with genes ZmLOX1 and ZmPLD1 in the same respective chromosomal regions.These QTL would be useful for screening for anti-aging genes in maize breeding.

  9. Associations of corticosterone and testosterone with alcohol drinking in F2 populations derived from AA and ANA rat lines.

    Science.gov (United States)

    Etelälahti, Tiina J; Saarikoski, Sirkku T; Eriksson, C J Peter

    2011-08-01

    In our previous studies on alcohol-preferring AA (Alko alcohol) and nonpreferring ANA (Alko nonalcohol) rats, we have observed that the AA rats exhibit lower endogenous levels of corticosterone, higher testosterone levels, and more frequent alcohol-induced testosterone elevations when compared with ANA rats. The objective of the present study was to get more conclusive evidence for the potential role of the hypothalamus-pituitary-adrenal and hypothalamus-pituitary-gonadal axes in alcohol drinking by using the F2 experimental design. Alcohol-preferring AA and alcohol-nonpreferring ANA rat lines were crossbred to form a F1 population from which the final F2 population was derived. Male animals were challenged with a priming alcohol dose after which a 3 weeks' voluntary alcohol drinking period took place. After a washout period of 1 week, one-half of the 40 highest and 40 lowest alcohol drinkers were challenged with a second dose of alcohol and the other half with saline. Serum testosterone and corticosterone levels were measured before and during the test. Higher endogenous testosterone levels were detected in the rats of the high alcohol consumption group compared with the low consumption group. Also supporting the original AA/ANA line differences, a trend for lower endogenous corticosterone levels were measured in the high alcohol consumption group compared with the low consumption group. The alcohol challenge test after the drinking period resulted in a higher frequency (38%) of testosterone elevations in the high drinkers compared with the low drinkers (5%). The present data confirms the validity of the positive connections between testosterone elevation and increased alcohol drinking, as well as between testosterone reduction and decreased alcohol drinking, in AA and ANA rats.

  10. Ischemic stroke in Ukrainian population: possible involvement of the F2 G20210A, F5 G1691A and MTHFR C677T gene variants

    Directory of Open Access Journals (Sweden)

    Kuznetsova S. M.

    2010-07-01

    Full Text Available Aim. To evaluate a possible involvement of the F2, F5, MTHFR gene variants into ischemic stroke pathogenesis in population of Ukraine. Methods. Polymorphic variants were analyzed in unrelated 183 stroke patients, 100 individuals from the general population of Ukraine and 88 healthy individuals elder than 65 years using PCR followed by RFLP analysis. Results. Unfavourable polymorphic variants F2 20210A, F5 1691A and MTHFR 677T were observed more frequently in patients with ischemic stroke comparing to control groups. Conclusions. F5 1691A and MTHFR 677T polymorphic variants are associated with the occurrence of ischemic stroke in women. F2 20210A is associated with the occurrence of ischemic stroke in men. Cumulative risk factor for stroke development is revealed in a combination of unfavorable polymorphic variants 20210A, 1691A and 677T of F2, F5 and MTHFR genes.

  11. Identification of quantitative trait loci associated with bone traits and body weight in an F2 resource population of chickens*

    Directory of Open Access Journals (Sweden)

    Schreiweis Melissa A

    2005-11-01

    Full Text Available Abstract Bone fractures at the end of lay are a significant problem in egg-laying strains of hens. The objective of the current study was to identify quantitative trait loci (QTL associated with bone mineralization and strength in a chicken resource population. Layer (White Leghorn hens and broiler (Cobb-Cobb roosters lines were crossed to generate an F2 population of 508 hens over seven hatches, and 26 traits related to bone integrity, including bone mineral density (BMD and content (BMC, were measured. Genotypes of 120 microsatellite markers on 28 autosomal groups were determined, and interval mapping was conducted to identify QTL regions. Twenty-three tests representing three chromosomal regions (chromosomes 4, 10 and 27 contained significant QTL that surpassed the 5% genome-wise threshold, and 47 tests representing 15 chromosomes identified suggestive QTL that surpassed the 5% chromosome-wise threshold. Although no significant QTL influencing BMD and BMC were detected after adjusting for variation in body weight and egg production, multiple suggestive QTL were found. These results support previous experiments demonstrating an important genetic regulation of bone strength in chickens, but suggest the regulation may be due to the effects of multiple genes that each account for relatively small amounts of variation in bone strength.

  12. Population analysis of open clusters: radii and mass segregation

    CERN Document Server

    Schilbach, E; Piskunov, A E; Röser, S; Scholz, R D

    2006-01-01

    Aims: Based on our well-determined sample of open clusters in the all-sky catalogue ASCC-2.5 we derive new linear sizes of some 600 clusters, and investigate the effect of mass segregation of stars in open clusters. Methods: Using statistical methods, we study the distribution of linear sizes as a function of spatial position and cluster age. We also examine statistically the distribution of stars of different masses within clusters as a function of the cluster age. Results: No significant dependence of the cluster size on location in the Galaxy is detected for younger clusters (< 200 Myr), whereas older clusters inside the solar orbit turned out to be, on average, smaller than outside. Also, small old clusters are preferentially found close to the Galactic plane, whereas larger ones more frequently live farther away from the plane and at larger Galactocentric distances. For clusters with (V - M_V) < 10.5, a clear dependence of the apparent radius on age has been detected: the cluster radii decrease by ...

  13. Association of PPARγ2 polymorphisms with carcass and meat quality traits in a Pietrain x Jinhua F2 population

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2011-01-01

    Full Text Available The PPARγ2 gene is a key regulator of both proliferation and preadipocyte differentiation in mammals. Herein its genotype and allele frequencies were analyzed using PCR-SSCP in eight pig breeds (N = 416. Two kinds of polymorphisms of the PPARγ2 gene were detected, including a previously reported shift SNP A177G (Met59Val in exon 1 and a novel silent mutation G876A in exon 5. The results revealed that European pig breeds carry a higher allele A frequency at the A177G locus and a fixed GG genotype at the G876A locus. Allele A at the G876A locus was only found in Jinhua pigs. The association between haplotype (A177G/G876A and carcass and meat quality traits was analyzed in a Pietrain x Jinhua F2 population (N = 248. The PPARγ2 gene was found to be significantly associated with backfat thickness at the shoulder (p < 0.05, 6-7th ribs (p < 0.01, last rib (p < 0.01, gluteus medius (p <0.05 and ham weight (p < 0.01. Significant effects of different haplotypes on ham weight and backfat thickness at the 6-7th ribs, last rib, and gluteus medius were also observed.

  14. Acyl sugars and whitefly (Bemisia tabaci) resistance in segregating populations of tomato genotypes.

    Science.gov (United States)

    Dias, D M; Resende, J T V; Marodin, J C; Matos, R; Lustosa, I F; Resende, N C V

    2016-04-07

    The wild tomato, Solanum pennellii, is an important source of resistance genes against tomato pests. This resistance is due to the presence of acyl sugars (AS), which are allelochemicals that have negative effects on arthropod pests. There are no commercially available tomato cultivars that exhibit significant levels of resistance to arthropod pests. Therefore, this study evaluated resistance to whitefly (Bemisia tabaci) in F2 and F2RC1 tomato genotypes with high AS levels from a cross between Solanum lycopersicum 'Redenção' and the S. pennellii accession, LA-716. Plants were exposed to B. tabaci biotype B at the pre-flowering stage. In both generations, there were significant, negative correlations between AS content and oviposition preference and nymph development. Whitefly exhibited a lower preference for oviposition and produced fewer nymphs in genotypes with high AS levels and the wild parent S. pennellii than in the low AS-level genotypes and Redenção cultivar, demonstrating that the breeding program was effective in transferring resistance to the F2 and F2RC1 generations. RVTA-2010-pl#31 and RVTA-2010-pl#94 in the F2 population are promising genotypes that produced materials with high AS levels in the F2RC1 generation (RVTA-2010-31-pl#177 and RVTA-2010-94-pl#381).

  15. Segregation of regulatory polymorphisms with effects on the gluteus medius transcriptome in a purebred pig population.

    Directory of Open Access Journals (Sweden)

    Angela Cánovas

    Full Text Available BACKGROUND: The main goal of the present study was to analyse the genetic architecture of mRNA expression in muscle, a tissue with an outmost economic importance for pig breeders. Previous studies have used F(2 crosses to detect porcine expression QTL (eQTL, so they contributed with data that mostly represents the between-breed component of eQTL variation. Herewith, we have analysed eQTL segregation in an outbred Duroc population using two groups of animals with divergent fatness profiles. This approach is particularly suitable to analyse the within-breed component of eQTL variation, with a special emphasis on loci involved in lipid metabolism. METHODOLOGY/PRINCIPAL FINDINGS: GeneChip Porcine Genome arrays (Affymetrix were used to determine the mRNA expression levels of gluteus medius samples from 105 Duroc barrows. A whole-genome eQTL scan was carried out with a panel of 116 microsatellites. Results allowed us to detect 613 genome-wide significant eQTL unevenly distributed across the pig genome. A clear predominance of trans- over cis-eQTL, was observed. Moreover, 11 trans-regulatory hotspots affecting the expression levels of four to 16 genes were identified. A Gene Ontology study showed that regulatory polymorphisms affected the expression of muscle development and lipid metabolism genes. A number of positional concordances between eQTL and lipid trait QTL were also found, whereas limited evidence of a linear relationship between muscle fat deposition and mRNA levels of eQTL regulated genes was obtained. CONCLUSIONS/SIGNIFICANCE: Our data provide substantial evidence that there is a remarkable amount of within-breed genetic variation affecting muscle mRNA expression. Most of this variation acts in trans and influences biological processes related with muscle development, lipid deposition and energy balance. The identification of the underlying causal mutations and the ascertainment of their effects on phenotypes would allow gaining a

  16. An F2 pig resource population as a model for genetic studies of obesity and obesity-related diseases in humans

    DEFF Research Database (Denmark)

    Kogelman, Lisette; Kadarmideen, Haja; Mark, Thomas;

    2013-01-01

    and obesity-related (OOR) traits. Using founder breeds divergent with respect to obesity traits we have created an F2 pig resource population (454 pigs), which has been intensively phenotyped for 36 OOR traits. The main rationale for our study is to characterize the genetic architecture of OOR traits in the F......2 pig design, by estimating heritabilities, genetic and phenotypic correlations using mixed- and multi-trait BLUP animal models. Our analyses revealed high coefficients of variation (15-42 per cent) and moderate to high heritabilities (0.22 - 0.81) in fatness traits, showing large phenotypic...

  17. Association mapping in multiple segregating populations of sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Stich, Benjamin; Melchinger, Albrecht E; Heckenberger, Martin; Möhring, Jens; Schechert, Axel; Piepho, Hans-Peter

    2008-11-01

    Association mapping in multiple segregating populations (AMMSP) combines high power to detect QTL in genome-wide approaches of linkage mapping with high mapping resolution of association mapping. The main objectives of this study were to (1) examine the applicability of AMMSP in a plant breeding context based on segregating populations of various size of sugar beet (Beta vulgaris L.), (2) compare different biometric approaches for AMMSP, and (3) detect markers with significant main effect across locations for nine traits in sugar beet. We used 768 F(n) (n = 2, 3, 4) sugar beet genotypes which were randomly derived from 19 crosses among diploid elite sugar beet clones. For all nine traits, the genotypic and genotype x location interaction variances were highly significant (P < 0.01). Using a one-step AMMSP approach, the total number of significant (P < 0.05) marker-phenotype associations was 44. The identification of genome regions associated with the traits under consideration indicated that not only segregating populations derived from crosses of parental genotypes in a systematic manner could be used for AMMSP but also populations routinely derived in plant breeding programs from multiple, related crosses. Furthermore, our results suggest that data sets, whose size does not permit analysis by the one-step AMMSP approach, might be analyzed using the two-step approach based on adjusted entry means for each location without losing too much power for detection of marker-phenotype associations.

  18. The non-segregated population of blue straggler stars in the remote globular cluster Palomar 14

    CERN Document Server

    Beccari, Giacomo; Ferraro, Francesco R; Lanzoni, Barbara; Bellazzini, Michele; De Marchi, Guido; Valls-Gabaud, David; Rood, Robert T

    2011-01-01

    We used deep wide-field observations obtained with the Canada-France-Hawaii Telescope to study the blue straggler star (BSS) population in the innermost five arcminutes of the remote Galactic globular cluster Palomar 14. The BSS radial distribution is found to be consistent with that of the normal cluster stars, showing no evidence of central segregation. Palomar 14 is the third system in the Galaxy (in addition to OmegaCentauri and NGC 2419) showing a population of BSS not centrally segregated. This is the most direct evidence that in Palomar 14 two-body relaxation has not fully established energy equipartition yet, even in the central regions (in agreement with the estimated half-mass relaxation time, which is significantly larger than the cluster age). These observational facts have important implications for the interpretation of the shape of the mass function and the existence of the tidal tails recently discovered in this cluster.

  19. Genetic Analysis and Physical Mapping of Lk-4(t), a Major Gene Controlling Grain Length in Rice, with a BC2F2 Population%一个控制水稻籽粒长度主效基因--Lk-4(t)的BC2F2群体定位及其遗传效应分析

    Institute of Scientific and Technical Information of China (English)

    周良强; 王玉平; 李仕贵

    2006-01-01

    Grain size and shape are important factors affecting grain quality and yield in rice. Mapping, tagging and identification of their related genes can lead us to understand their expression pattern and mechanism network, which is to their control. In this study we mapped a grain length controlling gene named Lk-4(t) with SSR and CAPs markers by screening 800 recessive plants in a BC2F2 population derived from a cross of Shuhui527×Xiaoli and backcrossed with Xiaoli as the donor parent. The distribution of grain shape parameters and thousand grain weight in F2 and BC2F2 population showed that backcross can diminish most unnecessary variations to identify the target gene more clearly. There were only two grain length phenotypes found among the 3 209 BC2F2 plants, long and short, indicating it is a qualitative trait. The frequency distribution for the grain length showed a typical segregation ratio of 3:1, suggesting that only one allele was responsible for the variation. By screening the recessive long grain plants with three CAPs markers, P1-EcoRV, P2-Sac Ⅰ and P3-Mbo Ⅰ, we tagged the locus on the arm of chromosome 3 near the centromere. Lk-4(t)was located between P1- EcoRV and P2-Sac Ⅰ, with genetic distance of 0.90 cM and 0.50 cM from the two markers respectively.Mapping of the gene is a foundation for its final identification and function analysis.%水稻籽粒大小和形状是影响稻米外观品质和产量的重要影响因素,对控制这些性状基因的定位和克隆有助于弄清籽粒大小基因的表达模式和相应的代谢系统,最终实现该性状的自由调控.运用SSR和CAPs标记对来源于蜀恢527//蜀恢527/小粒回交组合BC2F2群体800隐性长粒单株进行分析,定位了一个控制水稻籽粒长短的基因,Lk-4(t).对F2和BC2F2群体籽粒大小形状和千粒重的遗传分析表明,回交能将大部分对目的基因效应具有干扰修饰作用的微效基因多态性除去,从而有利于对目的基因型的准确鉴定;在F

  20. Genetic mapping and QTL analysis of agronomic traits in Indian Mucuna pruriens using an intraspecific F2 population

    Indian Academy of Sciences (India)

    S. Mahesh; M. Leelambika; Md Jaheer; A. M. Anithakumari; N. Sathyanarayana

    2016-03-01

    Mucuna pruriens is a well-recognized agricultural and horticultural crop with important medicinal use. However, antinutritional factors in seed and adverse morphological characters have negatively affected its cultivation. To elucidate the genetic control of agronomic traits, an intraspecific genetic linkage map of Indian M. pruriens has been developed based on amplified fragment length polymorphism (AFLP) markers using 200 F2 progenies derived from a cross between wild and cultivated genotypes. The resulting linkage map comprised 129 AFLP markers dispersed over 13 linkage groups spanning a total distance of 618.88 cM with an average marker interval of 4.79 cM. For the first time, three QTLs explaining about 6.05–14.77% of the corresponding total phenotypic variation for three quantitative (seed) traits and, eight QTLs explaining about 25.96% of the corresponding total phenotypic variation for three qualitative traits have been detected on four linkage groups. The map presented here will pave a way for mapping of genes/QTLs for the important agronomic and horticultural traits contrasting between the parents used in this study.

  1. Some AFLP amplicons are highly conserved DNA sequences mapping to the same linkage groups in two F2 populations of carrot

    Directory of Open Access Journals (Sweden)

    Santos Carlos A.F.

    2002-01-01

    Full Text Available Amplified fragment length polymorphism (AFLP is a fast and reliable tool to generate a large number of DNA markers. In two unrelated F2 populations of carrot (Daucus carota L., Brasilia x HCM and B493 x QAL (wild carrot, it was hypothesized that DNA 1 digested with the same restriction endonuclease enzymes and amplified with the same primer combination and 2 sharing the same position in polyacrylamide gels should be conserved sequences. To test this hypothesis AFLP fragments from polyacrylamide gels were eluted, reamplified, separated in agarose gels, purified, cloned and sequenced. Among thirty-one paired fragments from each F2 population, twenty-six had identity greater than 91% and five presented identity of 24% to 44%. Among the twenty-six conserved AFLPs only one mapped to different linkage groups in the two populations while four of the five less-conserved bands mapped to different linkage groups. Of eight SCAR (sequence characterized amplified regions primers tested, one conserved AFLP resulted in co-dominant markers in both populations. Screening among 14 carrot inbreds or cultivars with three AFLP-SCAR primers revealed clear and polymorphic PCR products, with similar molecular sizes on agarose gels. The development of co-dominant markers based on conserved AFLP fragments will be useful to detect seed mixtures among hybrids, to improve and to merge linkage maps and to study diversity and phylogenetic relationships.

  2. F2 screen for resistance to Bacillus thuringiensis Cry2Ab2-maize in field populations of Spodoptera frugiperda (Lepidoptera: Noctuidae) from the southern United States.

    Science.gov (United States)

    Niu, Ying; Qureshi, Jawwad A; Ni, Xinzhi; Head, Graham P; Price, Paula A; Meagher, Robert L; Kerns, David; Levy, Ronnie; Yang, Xiangbing; Huang, Fangneng

    2016-07-01

    The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a target pest of transgenic maize and cotton expressing Bacillus thuringiensis (Bt) proteins in both North and South America. In 2013 and 2014, a total of 215 F2 two-parent families of S. frugiperda were established using single-pair mating of field individuals collected from seven locations in four states of the southern U.S.: Texas, Louisiana, Georgia, and Florida. The objective of the investigation was to detect resistance alleles in field populations to Cry2Ab2, a common Bt protein produced in transgenic maize and cotton. For each F2 family, 128 F2 neonates were screened on leaf tissue of Cry2Ab2 maize plants in the laboratory. A conservative estimate of the frequency of major Cry2Ab2 resistance alleles in S. frugiperda from the four states was 0.0023 with a 95% credibility interval of 0.0003-0.0064. In addition, six families were considered to likely possess minor resistance alleles at a frequency of 0.0082 with a 95% credibility interval of 0.0033-0.0152. One F2 family from Georgia (GA-15) was confirmed to possess a major resistance allele to the Cry2Ab2 protein. Larvae from this family survived well on whole maize plants expressing Cry2Ab2 protein and demonstrated a significant level (>15-fold) of resistance when fed with the same protein incorporated in a meridic diet. The detection of the major resistance allele along with the relatively abundant minor resistance alleles revealed in this study may have important implications for resistance management.

  3. Identification of carcass and meat quality QTL in an F2 Duroc x Pietrain pig resource population using different least-squares analysis models

    Directory of Open Access Journals (Sweden)

    Igseo eChoi

    2011-05-01

    Full Text Available A three-generation resource population was constructed by crossing pigs from the Duroc and Pietrain breeds. In this study, 954 F2 animals were used to identify quantitative trait loci (QTL affecting carcass and meat quality traits. Based on results of the first scan analyzed with a line-cross model using 124 microsatellite markers and 510 F2 animals, 9 chromosomes were selected for genotyping of additional markers. Twenty additional markers were genotyped for 954 F2 animals and 20 markers used in the first scan were genotyped for 444 additional F2 animals. Three different Mendelian models using least-squares for QTL analysis were applied for the second scan: a line-cross model, a half-sib model, and a combined line-cross and half-sib model. Significance thresholds were determined by false discovery rate (FDR. In total, 50 QTL using the line-cross model, 38 QTL using the half-sib model and 3 additional QTL using the combined line-cross and half-sib model were identified (q < 0.05. The line-cross and half-sib models revealed strong evidence for QTL regions on SSC6 for carcass traits (e.g., 10th-rib backfat; q < 0.0001 and on SSC15 for meat quality traits (e.g., tenderness, color, pH; q < 0.01, respectively. QTL for pH (SSC3, dressing percent (SSC7, marbling score and moisture percent (SSC12, CIE a* (SSC16 and carcass length and spareribs weight (SSC18 were also significant (q < 0.01. Additional marker and animal genotypes increased the statistical power for QTL detection, and applying different analysis models allowed confirmation of QTL and detection of new QTL.

  4. Movement patterns and spatial segregation of two populations of lake trout Salvelinus namaycush in Lake Huron

    Science.gov (United States)

    Binder, Thomas; Marsden, J. Ellen; Riley, Stephen; Johnson, James E.; Johnson, Nicholas; He, Ji; Ebener, Mark P.; Holbrook, Christopher; Bergstedt, Roger A.; Bronte, Charles R.; Hayden, Todd A.; Krueger, Charles C.

    2017-01-01

    Movement ecology is an important component of life history and population dynamics, and consequently its understanding can inform successful fishery management decision-making. While lake trout populations in Lake Huron have shown signs of recovery from near extinction in recent years, knowledge of their movement behavior remains incomplete. We used acoustic telemetry to describe and compare movement patterns of two Lake Huron lake trout populations: Drummond Island and Thunder Bay. Both populations showed high spawning site fidelity, with no evidence of co-mingling during non-spawning season. Detections between spawning periods were mainly limited to receivers within 100 km of spawning locations, and suggested that the two populations likely remained segregated throughout the year. Drummond Island fish, which spawn inside the Drummond Island Refuge, primarily dispersed east into Canadian waters of Lake Huron, with 79–92% of fish being detected annually on receivers outside the refuge. In contrast, Thunder Bay fish tended to disperse south towards Saginaw Bay. Large proportions (i.e., > 80%) of both populations were available to fisheries outside the management zone containing their spawning location. Thunder Bay fish moved relatively quickly to overwinter habitat after spawning, and tended to repeat the same post-spawning movement behavior each year. The consistent, predictable movement of both populations across management zones highlights the importance of understanding population dynamics to effective management of Lake Huron lake trout.

  5. An F2 pig resource population as a model for genetic studies of obesity and obesity-related diseases in humans

    DEFF Research Database (Denmark)

    Kogelman, Lisette; Kadarmideen, Haja; Mark, Thomas

    2013-01-01

    Obesity is a rising worldwide public health problem. Difficulties to precisely measure various obesity traits and the genetic heterogeneity in human have been major impediments to completely disentangle genetic factors causing obesity. The pig is a relevant model for studying human obesity...... and obesity-related (OOR) traits. Using founder breeds divergent with respect to obesity traits we have created an F2 pig resource population (454 pigs), which has been intensively phenotyped for 36 OOR traits. The main rationale for our study is to characterize the genetic architecture of OOR traits in the F...

  6. Analysis of sequence variability in the pig CART gene and association of polymorphism with fatness traits in a F2 population.

    Science.gov (United States)

    Zhu, Xiaoping; Mo, Delin; Wang, Chong; Liu, Xiaohong; Li, Jiaqi; Ling, Fei; Chen, Yaosheng

    2014-08-01

    CART (cocaine- and amphetamine-regulated transcript) peptides are neuromodulators that are involved in appetite control and energy homeostasis. It can inhibit food intake and reduce body weight that have received much attention, but a direct and comprehensive relationship with pigs differing in fatness which could be applied to breeding well has not been established. This study aims to search for polymorphism within the porcine CART gene and evaluate the effect of specific genotypes with regards to an association with fatness traits in a F2 population consisting of 230 individuals. Screening of 2264 bp DNA fragment covering the entire CART gene revealed 29 mutations and four indels (insertion or a deletion), in which four unlinked SNPs (single-nucleotide polymorphisms) could be digested by enzymes and subsequently genotyped in two purebreds and a F2 population. Landrace (lean-type), one of purebreds, presented significantly higher CART expression level than Lantang (obese-type) in most tissues studied. Association analysis revealed that three SNPs (T415C, C640T and C847T) displayed significantly association (p CART expression among individuals with different genotypes, and the individuals with lower average live backfat thickness (BFAW) expressed CART protein at a bit higher level than others. Our study screened and mapped the genetic variations in the porcine CART gene, and confirmed three functional SNPs which are promising molecular markers for pig production traits.

  7. Mapping of QTL for tiller number at different stages of growth in wheat using double haploid and immortalized F2 populations

    Indian Academy of Sciences (India)

    Zhuokun Li; Tao Peng; Quangang Xie; Shuxiao Han; Jichun Tian

    2010-12-01

    Effective tiller number is one of the most important traits for wheat (Triticum aestivum L.) yield, but the inheritance of tillering is poorly understood. A set of 168 doubled haploid (DH) lines derivatives of a cross between two winter wheat cultivars (Huapei 3 and Yumai 57), and an immortalized F2 (IF2) population generated by randomly permutated intermating of these DHs were investigated, and QTLs of tillering related to the maximum tillering of pre-winter (MTW), maximum tillering in spring (MTS), and effective tillering in harvest (ETH) were mapped. Phenotypic data were collected for the two populations from two different environments. Using inclusive composite interval mapping (ICIM), a total of 9 and 18 significant QTL were detected across environments for tillering in the DH and IF2 populations, respectively. Four QTLs were common between two populations. A major QTL located on the 5D chromosome with the allele originating from Yumai 57 was detected and increased 1.92 and 3.55 tillers in MTW and MTS, respectively. QTLs (QMts6D, QEth6D) having a neighbouring marker interval at Xswes679.1 and Xcfa2129 on chromosome 6D was detected in MTS and ETH. These results provide a better understanding of the genetic factors for selectively expressing the control of tiller number in different growth stages and facilitate marker-assisted selection strategy in breeding.

  8. Sexual segregation in juvenile New Zealand sea lion foraging ranges: implications for intraspecific competition, population dynamics and conservation.

    Directory of Open Access Journals (Sweden)

    Elaine S Leung

    Full Text Available Sexual segregation (sex differences in spatial organisation and resource use is observed in a large range of taxa. Investigating causes for sexual segregation is vital for understanding population dynamics and has important conservation implications, as sex differences in foraging ecology may affect vulnerability to area-specific human activities. Although behavioural ecologists have proposed numerous hypotheses for this phenomenon, the underlying causes of sexual segregation are poorly understood. We examined the size-dimorphism and niche divergence hypotheses as potential explanations for sexual segregation in the New Zealand (NZ sea lion (Phocarctos hookeri, a nationally critical, declining species impacted by trawl fisheries. We used satellite telemetry and linear mixed effects models to investigate sex differences in the foraging ranges of juvenile NZ sea lions. Male trip distances and durations were almost twice as long as female trips, with males foraging over the Auckland Island shelf and in further locations than females. Sex was the most important variable in trip distance, maximum distance travelled from study site, foraging cycle duration and percent time at sea whereas mass and age had small effects on these characteristics. Our findings support the predictions of the niche divergence hypothesis, which suggests that sexual segregation acts to decrease intraspecific resource competition. As a consequence of sexual segregation in foraging ranges, female foraging grounds had proportionally double the overlap with fisheries operations than males. This distribution exposes female juvenile NZ sea lions to a greater risk of resource competition and bycatch from fisheries than males, which can result in higher female mortality. Such sex-biased mortality could impact population dynamics, because female population decline can lead to decreased population fecundity. Thus, effective conservation and management strategies must take into account

  9. Another Non-segregated Blue Straggler Population in a Globular Cluster: the Case of NGC 2419

    CERN Document Server

    Dalessandro, E; Ferraro, F R; Vespe, F; Bellazzini, M; Rood, R T

    2008-01-01

    We have used a combination of ACS-HST high-resolution and wide-field SUBARU data in order to study the Blue Straggler Star (BSS) population over the entire extension of the remote Galactic globular cluster NGC 2419. The BSS population presented here is among the largest ever observed in any stellar system, with more than 230 BSS in the brightest portion of the sequence. The radial distribution of the selected BSS is essentially the same as that of the other cluster stars. In this sense the BSS radial distribution is similar to that of omega Centauri and unlike that of all Galactic globular clusters studied to date, which have highly centrally segregated distributions and, in most cases, a pronounced upturn in the external regions. As in the case of omega Centauri, this evidence indicates that NGC 2419 is not yet relaxed even in the central regions. This observational fact is in agreement with estimated half-mass relaxation time, which is of the order of the cluster age.

  10. Analysis of porcine MUC4 gene as a candidate gene for prolificacy QTL on SSC13 in an Iberian × Meishan F2 population

    Directory of Open Access Journals (Sweden)

    Balcells Ingrid

    2011-10-01

    Full Text Available Abstract Background Reproductive traits, such as prolificacy, are of great interest to the pig industry. Better understanding of their genetic architecture should help to increase the efficiency of pig productivity through the implementation of marker assisted selection (MAS programmes. Results The Mucin 4 (MUC4 gene has been evaluated as a candidate gene for a prolificacy QTL described in an Iberian × Meishan (Ib × Me F2 intercross. For association analyses, two previously described SNPs (DQ124298:g.243A>G and DQ124298:g.344A>G were genotyped in 347 pigs from the Ib × Me population. QTL for the number of piglets born alive (NBA and for the total number of piglets born (TNB were confirmed on SSC13 at positions 44 cM and 51 cM, respectively. The MUC4 gene was successfully located within the confidence intervals of both QTL. Only DQ124298:g.344A>G MUC4 polymorphism was significantly associated with both NBA and TNB (P-value MUC4 expression level was determined in F2 sows displaying extreme phenotypes for the number of embryos (NE at 30-32 days of gestation. Differences in the uterine expression of MUC4 were found between high (NE ≥ 13 and low (NE ≤ 11 prolificacy sows. Overall, MUC4 expression in high prolificacy sows was almost two-fold increased compared with low prolificacy sows. Conclusions Our data suggest that MUC4 could play an important role in the establishment of an optimal uterine environment that would increase embryonic survival during pig gestation.

  11. Increasing the power to detect causal associations by combining genotypic and expression data in segregating populations.

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    2007-04-01

    Full Text Available To dissect common human diseases such as obesity and diabetes, a systematic approach is needed to study how genes interact with one another, and with genetic and environmental factors, to determine clinical end points or disease phenotypes. Bayesian networks provide a convenient framework for extracting relationships from noisy data and are frequently applied to large-scale data to derive causal relationships among variables of interest. Given the complexity of molecular networks underlying common human disease traits, and the fact that biological networks can change depending on environmental conditions and genetic factors, large datasets, generally involving multiple perturbations (experiments, are required to reconstruct and reliably extract information from these networks. With limited resources, the balance of coverage of multiple perturbations and multiple subjects in a single perturbation needs to be considered in the experimental design. Increasing the number of experiments, or the number of subjects in an experiment, is an expensive and time-consuming way to improve network reconstruction. Integrating multiple types of data from existing subjects might be more efficient. For example, it has recently been demonstrated that combining genotypic and gene expression data in a segregating population leads to improved network reconstruction, which in turn may lead to better predictions of the effects of experimental perturbations on any given gene. Here we simulate data based on networks reconstructed from biological data collected in a segregating mouse population and quantify the improvement in network reconstruction achieved using genotypic and gene expression data, compared with reconstruction using gene expression data alone. We demonstrate that networks reconstructed using the combined genotypic and gene expression data achieve a level of reconstruction accuracy that exceeds networks reconstructed from expression data alone, and that

  12. Multiplex pyrosequencing method to determine CYP2C9*3, VKORC1*2, and CYP4F2*3 polymorphisms simultaneously: its application to a Korean population and comparisons with other ethnic groups.

    Science.gov (United States)

    Kim, Kyoung-Ah; Song, Wan-Geun; Lee, Hae-Mi; Joo, Hyun-Jin; Park, Ji-Young

    2014-11-01

    Warfarin is an anticoagulant that is difficult to administer because of the wide variation in dose requirements to achieve a therapeutic effect. CYP2C9, VKROC1, and CYP4F2 play important roles in warfarin metabolism, and their genetic polymorphisms are related to the variability in dose determination. In this study we describe a new multiplex pyrosequencing method to identify CYP2C9*3 (rs1057910), VKORC1*2 (rs9923231), and CYP4F2*3 (rs2108661) simultaneously. A multiplex pyrosequencing method to simultaneously detect CYP2C9*3, VKORC1*2, and CYP4F2*3 alleles was designed. We assessed the allele frequencies of the polymorphisms in 250 Korean subjects using the multiplex pyrosequencing method. The results showed 100 % concordance between single and multiplex pyrosequencing methods, and the polymorphisms identified by pyrosequencing were also validated with the direct sequencing method. The allele frequencies of these polymorphisms in this population were as follows: 0.040 for CYP2C9*3, 0.918 for VKORC1*2, and 0.416 for CYP4F2*3. Although the allele frequencies of the CYP2C9*3 and VKROC1*2 were comparable to those in Japanese and Chinese populations, their frequencies in this Korean population differed from those in other ethnic groups; the CYP4F2*3 frequency was the highest among other ethnic populations including Chinese and Japanese populations. The pyrosequencing methods developed were rapid and reliable for detecting CYP2C9*3, VKORC1*2, and CYP4F2*3. Large ethnic differences in the frequency of these genetic polymorphisms were noted among ethnic groups. CYP4F2*3 exhibited its highest allele frequency among other ethnic populations compared to that in a Korean population.

  13. Crossing Methods and Cultivation Conditions for Rapid Production of Segregating Populations in Three Grain Amaranth Species.

    Science.gov (United States)

    Stetter, Markus G; Zeitler, Leo; Steinhaus, Adrian; Kroener, Karoline; Biljecki, Michelle; Schmid, Karl J

    2016-01-01

    Grain amaranths (Amaranthus spp.) have been cultivated for thousands of years in Central and South America. Their grains are of high nutritional value, but the low yield needs to be increased by selection of superior genotypes from genetically diverse breeding populations. Amaranths are adapted to harsh conditions and can be cultivated on marginal lands although little is known about their physiology. The development of controlled growing conditions and efficient crossing methods is important for research on and improvement of this ancient crop. Grain amaranth was domesticated in the Americas and is highly self-fertilizing with a large inflorescence consisting of thousands of very small flowers. We evaluated three different crossing methods (open pollination, hot water emasculation and hand emasculation) for their efficiency in amaranth and validated them with genetic markers. We identified cultivation conditions that allow an easy control of flowering time by day length manipulation and achieved flowering times of 4 weeks and generation times of 2 months. All three different crossing methods successfully produced hybrid F1 offspring, but with different success rates. Open pollination had the lowest (10%) and hand emasculation the highest success rate (74%). Hot water emasculation showed an intermediate success rate (26%) with a maximum of 94% success. It is simple to perform and suitable for a more large-scale production of hybrids. We further evaluated 11 single nucleotide polymorphism (SNP) markers and found that they were sufficient to validate all crosses of the genotypes used in this study for intra- and interspecific hybridizations. Despite its very small flowers, crosses in amaranth can be carried out efficiently and evaluated with inexpensive SNP markers. Suitable growth conditions strongly reduce the generation time and allow the control of plant height, flowering time, and seed production. In combination, this enables the rapid production of segregating

  14. Crossing methods and cultivation conditions for rapid production of segregating populations in three grain amaranth species

    Directory of Open Access Journals (Sweden)

    Markus G Stetter

    2016-06-01

    production of segregating populations which makes amaranth an attractive model for basic plant research but also facilitates further the improvement of this ancient crop by plant breeding.

  15. A whole genome scan to detect quantitative trait loci for gestation length and sow maternal ability related traits in a White Duroc × Erhualian F2 resource population.

    Science.gov (United States)

    Chen, C Y; Guo, Y M; Zhang, Z Y; Ren, J; Huang, L S

    2010-06-01

    Gestation length and maternal ability are important to improve the sow reproduction efficiency and their offspring survival. To map quantitative trait loci (QTL) for gestation length and maternal ability related traits including piglet survival rate and average body weight of piglets at weaning, more than 200 F2 sows from a White Duroc × Erhualian resource population were phenotyped. A genome-wide scan was performed with 194 microsatellite markers covering the whole pig genome. QTL analysis was carried out using a composite regression interval mapping method via QTL express. The results showed that total number of born piglets was significantly correlated with gestation length (r = -0.13, P gestation length. The QTL on SSC2 achieved the 5% genome-wide significant level and the QTL on SSC8 was consistent with previous reports. Four suggestive QTL were identified for maternal ability related traits including 1 QTL for survival rate of piglets at weaning on SSC8, 3 QTL for average body weight of piglet at weaning on SSC3, 11 and 13.

  16. Cyclic Co des over F2+uF2+v F2

    Institute of Scientific and Technical Information of China (English)

    LIU Xiu-sheng; LIU Hua-lu

    2014-01-01

    We study the structure of cyclic codes of an arbitrary length n over the ring F2+uF2+vF2, which is not a finite chain ring. We prove that the Gray image of a cyclic code length n over F2+uF2+vF2 is a 3-quasi-cyclic code length 3n over F2.

  17. Associação de Pseudomonas syringae pv. garcae com algumas características agronômicas em cafeeiros F2 segregantes para o gene erecta Pseudomonas syringae pv. garcae and some agronomic traits association in F2 coffee plants segregating to the erecta gene

    Directory of Open Access Journals (Sweden)

    Gustavo Hiroshi Sera

    2004-10-01

    Full Text Available A bacteriose causada pela Pseudomonas syringae pv. garcae provoca grandes prejuízos em algumas regiões da cafeicultura brasileira, como Paraná, São Paulo e Minas Gerais, principalmente em lavouras novas, podadas e expostas ao vento. Com este trabalho, objetivou-se estudar nas plantas F2 do cruzamento entre os genótipos IAPAR-59 e Catuaí Erecta a associação entre as características vigor vegetativo e ângulos de inserção das ramificações plagiotrópicas sobre a intensidade de ocorrência da bacteriose. Avaliaram-se, em outubro de 2001, 316 plantas F2 plantadas no IAPAR de Londrina em outubro de 1998. A escala de notas de avaliação da incidência de bacteriose adotada foi de 1 a 5, sendo 1 = plantas sem lesão e 5 = plantas com muitas lesões. As notas de vigor vegetativo adotadas foram de 1 a 5, sendo 1 para folhas de coloração verde-claras e 5 para folhas verdeescuras. Para a inserção dos ramos plagiotrópicos sobre os ortotrópicos, as notas variaram de 1 a 3, sendo 1 = normal (45 a 70º, 2 = semi-ereta (25 a 40º e 3 = ereta (5 a 20º. Estimou-se o coeficiente de correlação de Pearson para verificar a associação entre as características vigor vegetativo e do ângulo de inserção das ramificações plagiotrópicas com a intensidade de ocorrência da bacteriose nos cafeeiros. A correlação estimada entre a intensidade da bacteriose com o ângulo de inserção dos ramos plagiotrópicos foi de r = + 0,2087**. Não houve correlação significativa entre a bacteriose e o vigor vegetativo. Assim, plantas com ramificação plagiotrópica ereta são predispostas a uma maior incidência de bacteriose.Bacteriosis caused by Pseudomonas syringae pv garcae causes significant damage in important brazilian coffee regions, mainly affecting young and pruned coffee plants and plants exposed to the wind. The objective of this research was to establish the association between vegetative vigor and types of plagiotropic branches in the

  18. Genetic dissection of the maize kernel development process via conditional QTL mapping for three developing kernel-related traits in an immortalized F2 population.

    Science.gov (United States)

    Zhang, Zhanhui; Wu, Xiangyuan; Shi, Chaonan; Wang, Rongna; Li, Shengfei; Wang, Zhaohui; Liu, Zonghua; Xue, Yadong; Tang, Guiliang; Tang, Jihua

    2016-02-01

    Kernel development is an important dynamic trait that determines the final grain yield in maize. To dissect the genetic basis of maize kernel development process, a conditional quantitative trait locus (QTL) analysis was conducted using an immortalized F2 (IF2) population comprising 243 single crosses at two locations over 2 years. Volume (KV) and density (KD) of dried developing kernels, together with kernel weight (KW) at different developmental stages, were used to describe dynamic changes during kernel development. Phenotypic analysis revealed that final KW and KD were determined at DAP22 and KV at DAP29. Unconditional QTL mapping for KW, KV and KD uncovered 97 QTLs at different kernel development stages, of which qKW6b, qKW7a, qKW7b, qKW10b, qKW10c, qKV10a, qKV10b and qKV7 were identified under multiple kernel developmental stages and environments. Among the 26 QTLs detected by conditional QTL mapping, conqKW7a, conqKV7a, conqKV10a, conqKD2, conqKD7 and conqKD8a were conserved between the two mapping methodologies. Furthermore, most of these QTLs were consistent with QTLs and genes for kernel development/grain filling reported in previous studies. These QTLs probably contain major genes associated with the kernel development process, and can be used to improve grain yield and quality through marker-assisted selection.

  19. Urinary 8-iso-prostaglandin F2α as a marker of metabolic risks in the general Japanese population: The ROAD study.

    Science.gov (United States)

    Mure, Kanae; Yoshimura, Noriko; Hashimoto, Marowa; Muraki, Shigeyuki; Oka, Hiroyuki; Tanaka, Sakae; Kawaguchi, Hiroshi; Nakamura, Kozo; Akune, Toru; Takeshita, Tatsuya

    2015-07-01

    To determine whether 8-iso-prostaglandin F2α (8-iso-PGF2α) is a reliable biomarker of the accumulation of metabolic risks [e.g., overweight, hypertension, impaired glucose tolerance (IGT), and dyslipidemia]. This was a cross-sectional study of the baseline characteristics of a Japanese general population cohort study: Research on Osteoarthritis/Osteoporosis Against Disability (ROAD). Of 1,690 participants, 1,527 fulfilled all questionnaires and examinations. Free and conjugated urinary 8-iso-PGF2α levels and metabolic syndrome (MetS) components including blood pressure, HbA1c, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and non-HDL-C were analyzed. The data were analyzed by ANCOVA, multiple regression analysis, and multinomial logistic analysis. 8-iso-PGF2α was significantly associated with HbA1c and significantly inversely associated with total cholesterol and non-HDL-C. Notably, IGT with an HbA1c cut-off of 5.5% was significantly associated with 8-iso-PGF2α level in participants aged ≤50 years. Multinomial logistic regression analysis revealed 8-iso-PGF2α level was significantly associated with a greater number of MetS risks present; this association was stronger in younger participants. In participants aged ≥71 years, 8-iso-PGF2α was significantly associated with a greater number of MetS risks with higher IGT cut-offs. Urinary 8-iso-PGF2α can be a reliable marker of IGT and the accumulation of MetS risks, especially in younger people. © 2015 The Obesity Society.

  20. Profiling and characterization of a longissimus dorsi muscle microRNA dataset from an F2 Duroc × Pietrain pig resource population

    Directory of Open Access Journals (Sweden)

    Kaitlyn R. Daza

    2017-09-01

    Full Text Available To elucidate the effects of microRNA (miRNA regulation in skeletal muscle of adult pigs, miRNA expression profiling was performed with RNA extracted from longissimus dorsi (LD muscle samples from 174 F2 pigs (~5.5 months of age from a Duroc × Pietrain resource population. Total RNA was extracted from LD samples, and libraries were sequenced on an Illumina HiSeq 2500 platform in 1 × 50 bp format. After processing, 232,826,977 total reads were aligned to the Sus scrofa reference genome (v10.2.79, with 74.8% of total reads mapping successfully. The miRDeep2 software package was utilized to quantify annotated Sus scrofa mature miRNAs from miRBase (Release 21 and to predict candidate novel miRNA precursors. Among the retained 295 normalized mature miRNA expression profiles ssc­miR­1, ssc­miR­133a­3p, ssc­miR­378, ssc­miR­206, and ssc­miR­10b were the most abundant, all of which have previously been shown to be expressed in pig skeletal muscle. Additionally, 27 unique candidate novel miRNA precursors were identified exhibiting homologous sequence to annotated human miRNAs. The composition of classes of small RNA present in this dataset was also characterized; while the majority of unique expressed sequence tags were not annotated in any of the queried databases, the most abundantly expressed class of small RNA in this dataset was miRNAs. This data provides a resource to evaluate miRNA regulation of gene expression and effects on complex trait phenotypes in adult pig skeletal muscle. The raw sequencing data were deposited in the Sequence Read Archive, BioProject PRJNA363073.

  1. F2 screen for resistance to Bacillus thuringiensis Cry2Ab2-maize in field populations of Spodoptera frugiperda (Lepidoptera: Noctuidae) from the southern United States

    Science.gov (United States)

    The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a target of transgenic maize and cotton expressing Bacillus thuringiensis (Bt) proteins in both North and South America. In 2013 and 2014, a total of 215 F2 two-parent families of S. frugiperda were established usin...

  2. Coexistence of oceanic predators on wintering areas explained by population-scale foraging segregation in space or time.

    Science.gov (United States)

    Thiebot, Jean-Baptiste; Cherel, Yves; Trathan, Philip N; Bost, Charles-André

    2012-01-01

    Ecological niche theory predicts segregation mechanisms that mitigate potential competition between closely related organisms. However, little is known outside the breeding season, when central-place foraging animals may move on larger scales. This study tested for segregation mechanisms within the same 2007 inter-breeding period on three neighboring populations of avian predators from the southern Indian Ocean: Eastern Rockhopper Penguins Eudyptes filholi from Crozet and Kerguelen and Northern Rockhopper Penguins E. moseleyi from Amsterdam. Using state-of-the-art geolocation tracking and stable isotope analysis techniques, we quantified and compared the ecological niches in time, space, and diet. The three populations showed large-scale movements over deep oceanic waters near the Subantarctic Front, with generally little individual variation. The two neighboring populations of Eastern Rockhopper Penguins showed strikingly distinct distribution in space, while foraging in similar habitats and at the same trophic level (crustacean-eaters). In contrast, Northern Rockhoppers showed marked spatial overlap with birds of the sibling Eastern species, but their temporal delay of two months enabled them to effectively avoid significant overlap. Our results highlight parsimonious mechanisms of resource partitioning operating at the population level that may explain how animals from neighboring localities can coexist during the nonbreeding period.

  3. Disomic Inheritance and Segregation Distortion of SSR Markers in Two Populations of Cynodon dactylon (L. Pers. var. dactylon.

    Directory of Open Access Journals (Sweden)

    Yuanwen Guo

    Full Text Available Common bermudagrass [C. dactylon (L. Pers. var. dactylon] is economically and environmentally the most important member among Cynodon species because of its extensive use for turf, forage and soil erosion control in the world. However, information regarding the inheritance within the taxon is limited. Accordingly, the objective of this study was to determine qualitative inheritance mode in common bermudagrass. Two tetraploid (2n = 4x = 36, first-generation selfed (S1 populations, 228 progenies of 'Zebra' and 273 from A12359, were analyzed for segregation with 21 and 12 simple sequence repeat (SSR markers, respectively. It is concluded that the inheritance mode of tetraploid bermudagrass was complete or near complete disomic. It is evident that the two bermudagrass parents had an allotetraploid genome with two distinct subgenomes since 33 SSR primer pairs amplified 34 loci, each having two alleles. Severe transmission ratio distortions occurred in the Zebra population while less so in the A12359 population. The findings of disomic inheritance and segregation ratio distortion in common bermudagrass is significant in subsequent linkage map construction, quantitative trait locus mapping and marker-assisted selection in the species.

  4. Elevated Genetic Diversity in an F2:6 Population of Quinoa (Chenopodium quinoa) Developed through an Inter-ecotype Cross

    OpenAIRE

    Benlhabib, Ouafae; Boujartani, Noura; Maughan, Peter J.; Jacobsen, Sven-Erik; Jellen, Eric N.

    2016-01-01

    Quinoa (Chenopodium quinoa) is a seed crop of the Andean highlands and Araucanian coastal regions of South America that has recently expanded in use and production beyond its native range. This is largely due to its superb nutritional value, consisting of protein that is rich in essential amino acids along with vitamins and minerals. Quinoa also presents a remarkable degree of tolerance to saline conditions, drought, and frost. The present study involved 72 F2:6 recombinant-inbred lines and p...

  5. Herbicide hormesis to segregate a weed population? – A case study with Tripleurospermum perforatum (Mérat Lainz

    Directory of Open Access Journals (Sweden)

    Belz, Regina G.

    2016-02-01

    Full Text Available Weed populations feature within-population genetic differences. Thus, evaluating mean responses in herbicide treated populations may miss ecologically significant individual responses. Since hormesis can likewise vary between individuals, this study investigated the hypothesis that herbicide hormesis within a high-density weed population is different among slowly-growing individuals, as compared to fast-growing individuals. In a dose-response experiment, Tripleurospermum perforatum (Mérat Lainz was exposed to 12 doses of Atlantis WG (mesosulfuron + iodosulfuron in 24 replicates (50 plants/replicate. Root/shoot growth responses were evaluated as dose-response relationships for the population mean, the 90-97th percentile of the population (fast-growing individuals, and the 5-10th percentile (slow-growing individuals. Growth responses were generally biphasic. Slow-growing individuals had more pronounced hormesis that occurred partially at lower doses as compared to the population mean. With fast-growing individuals, hormesis was instead less pronounced and partially shifted to higher doses. Hence, hormesis was primarily associated with a stimulation of slow-growing individuals, while fast-growing individuals contributed to a lesser extent to the hormetic population response in a dense stand in vitro. This discrepancy may have the potential to segregate an herbicide exposed population and alter its sensitivity in the long-run.

  6. Desempenho de populações híbridas F2 de arroz-vermelho (Oryza sativa com arroz transgênico (O. sativa resistente ao herbicida amonio-glufosinate Performance of F2 hybrid populations of red rice (Oryza sativa with ammonium-glufosinate-resistant transgenic rice (O. sativa

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2004-09-01

    -preto. Mesmo assim, os usuários dessa tecnologia deverão adotar, obrigatoriamente, medidas que evitem a possibilidade de cruzamento entre o arroz transgênico e o arroz-vermelho ou arroz-preto.Red rice is an important weed in paddy rice fields. The use of ammonium glufosinate - resistant genetically modified (GM rice cultivars is a viable alternative for controlling red rice in cultivated rice crops. The objective of this study was to evaluate the behavior of F2 hybrid population derivates of crossing between ammonium glufosinate - resistant GM rice and red rice. The F2 hybrid population derivates of crossing between GM rice and red rice are viable but do not present any apparent competitive advantage over red rice. The morphological characteristics of the F2 hybrid populations, such as tillering capacity, number of leaves produced and average plant height were partly reduced and partly unaffected by the introgression of the bar gene. The period between rice planting and 50% flowering increased in the red rice x GM rice F2 hybrids, compared to the parental red rice and GM rice. Average seed shattering rate in the four hybrid families was lower than in the red rice ecotypes, with such aspect also being unfavorable to the persistence of red rice in the environment. Seed dormancy of the hybrids was similar to that of the red rice ecotypes. However, management practices should be adopted to avoid crossing between transgenic rice and red rice.

  7. Population overlap and habitat segregation in wintering Black-tailed Godwits Limosa limosa

    NARCIS (Netherlands)

    Alves, Jose A.; Lourenco, Pedro M.; Piersma, Theunis; Sutherland, William J.; Gill, Jennifer A.

    2010-01-01

    Capsule Distinct breeding populations of migratory species may overlap both spatially and temporally, but differ in patterns of habitat use. This has important implications for population monitoring and conservation. Aims To quantify the extent to which two distinct breeding populations of a migrato

  8. 利用分子标记确定从水稻3N×2N组合中 得到的F2群体稳定性%Identification of F2 Population Derived from the Cross of3N×2N in Rice Using RFLP and SSR Markers

    Institute of Scientific and Technical Information of China (English)

    邢少辰; 周开达; 朱立煌; 蔡玉红; 庄炳昌

    2001-01-01

    同源三倍体株系43是从水稻双胚苗株系9004群体中筛选出来的。用它作为母本和正常的二倍体粳稻品种"中丹2号”杂交,得到了具有双亲性状的二倍体后代,收获其自交结实种子,次年获得一个表现稳定一致的F2群体,编号"942”。为了证实这个群体稳定的真实性,利用RFLP和SSR 2种分子标记进行了验证。结果表明:这个群体在分子水平上是稳定一致的。%Autotriploid strain 43 selected from twin-seedlings 9004 population was crossed with diploid japon ic a variety zhongdan 2. Some diploid F1 plants were obtained and one stable F2 popu lation No. 942 was generated from the inbred F1 seeds next year.To prove its s ta bility,We employed the RFLP and SSR markers.The results showed that the F2 pop ul ation is uniform at molecular level.

  9. 雄性不交换条件下F2群体区间标记——QTL定位的相关方法(英文)%A Correlation Method for Mapping Quantitative Trait Loci Using Flanking Markers in F2 Population with Male Un-crossover

    Institute of Scientific and Technical Information of China (English)

    李宏

    2002-01-01

    提出了雄性不交换条件下F2群体区间标记定位QTL的相关方法,并且对其适用的条件进行了讨论.通过对分子区间标记进行赋值,计算在无交叉干涉条件下分子标记与表型值的简单相关系数,并在此基础上进行连锁检验,在特定条件下可以估计数量性状座位(QTL)与分子标记座位间的连锁值.%The correlation method for mapping quantitative trait loci using flanking markers in F2 population with male un-crossover was provided and its application conditions were discussed. The author presents a method that give a value assignment and try to obtain a simple correlation coefficient R to phenotypic value of quantitative trait in condition of chiasma interference. then,on the basis,we can go on detecting linkage.Moreover,under certain condition,the recombination value between quantitative trait loci(QTL) and marker loci(ML) could be estimated by using R.

  10. Evaluating the Polyphenol Profile in Three Segregating Grape (Vitis vinifera L. Populations

    Directory of Open Access Journals (Sweden)

    Alberto Hernández-Jiménez

    2013-01-01

    Full Text Available This paper explores the characteristics of the anthocyanin and flavonol composition and content in grapes from plants resulting from intraspecific crosses of Vitis vinifera varieties Monastrell × Cabernet Sauvignon, Monastrell × Syrah, and Monastrell × Barbera, in order to acquire information for future breeding programs. The anthocyanin and flavonol compositions of twenty-seven hybrids bearing red grapes and 15 hybrids bearing white grapes from Monastrell × Syrah, 32 red and 6 white from Monastrell × Cabernet Sauvignon, and 13 red from Monastrell × Barbera have been studied. Among the intraspecific crosses, plants with grapes presenting very high concentrations of anthocyanins and flavonols were found, indicating a transgressive segregation for this character, and this could lead to highly colored wines with an increased benefits for human health. As regards the qualitative composition of anthocyanins and flavonols, the hydroxylation pattern of the hybrids that also may influence wine color hue and stability presented intermediate values to those of the parentals, indicating that values higher than that showed by the best parental in this respect will be difficult to obtain. The results presented here can be helpful to acquire information for future breeding efforts, aimed at improving fruit quality through the effects of flavonoids.

  11. Stable Isotopes Provide Insight into Population Structure and Segregation in Eastern North Atlantic Sperm Whales

    DEFF Research Database (Denmark)

    Borrell, Asuncion; Velasquez Vacca, Adriana; Pinela, Ana M.;

    2013-01-01

    In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly h...

  12. Genome-wide association study reveals constant and specific loci for hematological traits at three time stages in a White Duroc × Erhualian F2 resource population.

    Directory of Open Access Journals (Sweden)

    Zhiyan Zhang

    Full Text Available Hematological traits are important indicators of immune function and have been commonly examined as biomarkers of disease and disease severity in humans. Pig is an ideal biomedical model for human diseases due to its high degree of similarity with human physiological characteristics. Here, we conducted genome-wide association studies (GWAS for 18 hematological traits at three growth stages (days 18, 46 and 240 in a White Duroc × Erhualian F2 intercross. In total, we identified 38 genome-wide significant regions containing 185 genome-wide significant SNPs by single-marker GWAS or LONG-GWAS. The significant regions are distributed on pig chromosomes (SSC 1, 4, 5, 7, 8, 10, 11, 12, 13, 17 and 18, and most of significant SNPs reside on SSC7 and SSC8. Of the 38 significant regions, 7 show constant effects on hematological traits across the whole life stages, and 6 regions have time-specific effects on the measured traits at early or late stages. The most prominent locus is the genomic region between 32.36 and 84.49 Mb on SSC8 that is associated with multiple erythroid traits. The KIT gene in this region appears to be a promising candidate gene. The findings improve our understanding of the genetic architecture of hematological traits in pigs. Further investigations are warranted to characterize the responsible gene(s and causal variant(s especially for the major loci on SSC7 and SSC8.

  13. Asymmetric Damage Segregation Constitutes an Emergent Population-Level Stress Response

    DEFF Research Database (Denmark)

    Vedel, Søren; Nunns, Harry; Košmrlj, Andrej

    2016-01-01

    , we introduce a cell-lineage-based framework that quantifies the population-wide effects of ADS and then verify our results experimentally in E. coli under heat and antibiotic stress. Using an experimentally validated mathematical model, we find that the beneficial effect of ADS increases with stress....... In effect, low-damage subpopulations divide faster and amplify within the population acting like a positive feedback loop whose strength scales with stress. Analysis of protein aggregates shows that the degree of asymmetric inheritance is damage dependent in single cells. Together our results indicate that...

  14. Stable Isotopes Provide Insight into Population Structure and Segregation in Eastern North Atlantic Sperm Whales

    Science.gov (United States)

    Borrell, Asunción; Velásquez Vacca, Adriana; Pinela, Ana M.; Kinze, Carl; Lockyer, Christina H.; Vighi, Morgana; Aguilar, Alex

    2013-01-01

    In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we measured oxygen- isotope ratios (δ18O) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (δ15N: δ13C) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in δ15N and δ18O values in the layer deposited at age 3, considered to be the one best representing the baseline of the breeding ground, in δ15N, δ13C and δ18O values in the period up to age 20, and in the ontogenetic variation of δ15N and δ18O values. These differences evidence that diet composition, use of habitat and/or migratory destinations are dissimilar between whales from the two regions and suggest that the North Atlantic population of sperm whales is more structured than traditionally accepted. PMID:24324782

  15. Public availability of a genotyped, segregating population may foster marker assisted breeding (MAB) and quantitative trait loci (QTL) discovery: An example using strawberry

    Science.gov (United States)

    Much of the cost associated with marker discovery for marker assisted breeding (MAB) can be eliminated if a diverse, segregating population is generated, genotyped and made available to the global breeding community. Herein, we present an example of a hybrid, wild-derived family of the octoploid str...

  16. Segregated Cell Populations Enable Distinct Parallel Encoding within the Radial Axis of the CA1 Pyramidal Layer

    Science.gov (United States)

    Geiller, Tristan; Royer, Sebastien

    2017-01-01

    Numerous studies have implicated the hippocampus in the encoding and storage of declarative and spatial memories. Several models have considered the hippocampus and its distinct subfields to contain homogeneous pyramidal cell populations. Yet, recent studies have led to a consensus that the dorso-ventral and proximo-distal axes have different connectivities and physiologies. The remaining deep-superficial axis of the pyramidal layer, however, remains relatively unexplored due to a lack of techniques that can record from neurons simultaneously at different depths. Recent advances in transgenic mice, two-photon imaging and dense multisite recording have revealed extensive disparities between the pyramidal cells located in the deep and the superficial layers. Here, we summarize differences between the two populations in terms of gene expression and connectivity with other intra-hippocampal subregions and local interneurons that underlie distinct learning processes and spatial representations. A unified picture will emerge to describe how such local segregations can increase the capacity of the hippocampus to compute and process numerous tasks in parallel. PMID:28243162

  17. Genetic dissection of sorghum grain quality traits using diverse and segregating populations.

    Science.gov (United States)

    Boyles, Richard E; Pfeiffer, Brian K; Cooper, Elizabeth A; Rauh, Bradley L; Zielinski, Kelsey J; Myers, Matthew T; Brenton, Zachary; Rooney, William L; Kresovich, Stephen

    2017-04-01

    Coordinated association and linkage mapping identified 25 grain quality QTLs in multiple environments, and fine mapping of the Wx locus supports the use of high-density genetic markers in linkage mapping. There is a wide range of end-use products made from cereal grains, and these products often demand different grain characteristics. Fortunately, cereal crop species including sorghum [Sorghum bicolor (L.) Moench] contain high phenotypic variation for traits influencing grain quality. Identifying genetic variants underlying this phenotypic variation allows plant breeders to develop genotypes with grain attributes optimized for their intended usage. Multiple sorghum mapping populations were rigorously phenotyped across two environments (SC Coastal Plain and Central TX) in 2 years for five major grain quality traits: amylose, starch, crude protein, crude fat, and gross energy. Coordinated association and linkage mapping revealed several robust QTLs that make prime targets to improve grain quality for food, feed, and fuel products. Although the amylose QTL interval spanned many megabases, the marker with greatest significance was located just 12 kb from waxy (Wx), the primary gene regulating amylose production in cereal grains. This suggests higher resolution mapping in recombinant inbred line (RIL) populations can be obtained when genotyped at a high marker density. The major QTL for crude fat content, identified in both a RIL population and grain sorghum diversity panel, encompassed the DGAT1 locus, a critical gene involved in maize lipid biosynthesis. Another QTL on chromosome 1 was consistently mapped in both RIL populations for multiple grain quality traits including starch, crude protein, and gross energy. Collectively, these genetic regions offer excellent opportunities to manipulate grain composition and set up future studies for gene validation.

  18. Índice de seleção para escolha de populações segregantes de feijoeiro-comum Selection index for choosing segregating populations in common bean

    Directory of Open Access Journals (Sweden)

    Flávia Ferreira Mendes

    2009-10-01

    Full Text Available Os objetivos deste trabalho foram determinar a viabilidade de uso de um índice de seleção baseado em somatório de variáveis padronizadas no melhoramento genético do feijoeiro-comum e identificar as populações segregantes mais promissoras em produtividade de grãos, porte da planta e resistência ao acamamento, simultaneamente. Foram avaliadas populações segregantes obtidas por cruzamentos em esquema de dialelo parcial (6x6. Os genitores utilizados foram divididos em dois grupos. No grupo I, foram utilizados genitores com grãos do tipo carioca, de porte semiereto a prostrado. No grupo II, foram utilizados genitores com porte ereto, porém com grãos fora do padrão comercial carioca. As gerações F2 e F3 das combinações híbridas foram avaliadas em experimentos com delineamento de blocos ao acaso, com três repetições e semeadura em novembro de 2007 e fevereiro de 2008, respectivamente. Os dados relativos à produtividade de grãos, à nota de porte e à nota de acamamento foram padronizados (Zij por parcela. A partir do somatório de Zij, obteve-se o índice de seleção para as três características conjuntamente. Constatou-se que o índice de seleção possibilita selecionar populações segregantes superiores, considerando simultaneamente a produtividade de grãos e as notas de porte e de acamamento. As populações segregantes CV III 8511 x BRS 7762 Supremo, CV III 8511 x RP 166 e CV III 8511 x RP 26 são indicadas para programas de melhoramento a fim de obter linhagens produtivas com plantas eretas e menor acamamento.The objectives of this work were to determine the viability of using a selection index based on the sum of standardized variables in common bean breeding programs, and to identify the most promising segregating populations for grain productivity, plant growth habit and resistance to lodging simultaneously. Segregant populations obtained by crosses in partial diallel scheme (6x6 were evaluated. Parental

  19. IDENTIFIKASI ZIGOSITAS IKAN LELE (Clarias gariepinus TRANSGENIK F-2 YANG MEMBAWA GEN HORMON (PhGH DENGAN MENGGUNAKAN METODE REALTIME-qPCR

    Directory of Open Access Journals (Sweden)

    Huria Marnis

    2016-11-01

    Fish farming productivity can be increased by transgenesis technology. On the previous study, transgenic African catfish population fast growing has been produced and its biological characters has been known. However information of transgenic zygosity of catfish should be examined. The aim of this study was to identify the zygosity of F-2 transgenic African catfish. The zygosity of F-2 transgenic was identified by real time-qPCR (RT-qPCR method and progeny test. Further, identification of zygosity F-2 transgenic African catfish was confirmed by progeny test, while F-2 transgenic African catfish was mated with non-transgenic. Identification of zygosity F-2 transgenic was conducted by detection PhGH gene (transgene in F-3 transgenic African catfish population. Transgene transmission was evaluated by PCR method. The result showed that the zygosity F-2 transgenic African catfish could be identified by RT-qPCR method. All F-2 transgenic African catfish were heterozygous, where as the 2-Ct value was almost same for all individual, which ranges from 0.80 to 0.99. The result of zygosity identification using RT-qPCR method was as same as that of progeny test. In the progeny test, transgene transmission in this study was non-Mendelian segregation, with ranges of 5%-40%.

  20. Melhoramento do cafeeiro: XXXI - Ensaio de populações F2 de híbridos entre cultivares de Coffea arabica Coffee breeding: XXXI - Results of a field trial comprising several F2 populations derived from hybridization between cultivars of Coffea arabica

    Directory of Open Access Journals (Sweden)

    A. Carvalho

    1967-01-01

    Full Text Available São apresentados dados referentes à produção de café cereja em seis anos consecutivos, de um ensaio em que seis populações F2 derivadas dos cultivares 'Mundo Novo', 'Bourbon Amarelo', 'Bourbon Vermelho', 'Caturra Amarelo' e 'Caturra Vermelho' são analisadas. Duas populações destacaram-se pela produtividade e tipo de planta, e alguns de seus representantes foram escolhidos para estudo da F3 e prosseguimento do plano de melhoramento. Dessas populações a mais promissora corresponde à F2 da hibridação entre a planta CP 374-19 de 'Mundo Novo' e CJ 24-6 de 'Bourbon Amarelo'. Analisaram-se as variações da produção em cada um dos seis anos consecutivos, separadamente e em conjunto, e também os dados referentes à produção acumulada de dois e quatro primeiros anos, a fim de compará-los com os dados de produção total dos seis anos de produções consecutivas. Os resultados mostram que a classificação das populações depois do quarto ano é bastante semelhante à obtida após a análise de seis anos de produção. A análise das plantas individuais mostrou que nas populações F2 estudadas é bastante reduzida a proporção de cafeeiros valiosos para prosseguimento da seleção.The existence of several major genetic factors affecting important agronomic characteristics has led the coffee breeders to use them in their breeding program. The gene Ct (reduced growth and xc (yellow pericarp and better out-turn have been used rather extensively in an attempt to reduce the height of the 'Bourbon Amarelo' and improve the out-turn of the 'Mundo Novo' cultivars. Some data of a series of hybrids between 'Bourbon Amarelo', 'Caturra Amarelo', 'Caturra Vermelho', 'Bourbon Vermelho' and 'Mundo Novo' are discussed in the present paper. As expected, due to the origin of these cultivars, the F2 generation showed little genetic variation. Some of the new recombinants carrying the desirable major genetic factors, were shown to be inferior to the

  1. Stable Isotopes Provide Insight into Population Structure and Segregation in Eastern North Atlantic Sperm Whales

    DEFF Research Database (Denmark)

    Borrell, Asuncion; Velasquez Vacca, Adriana; Pinela, Ana M.

    2013-01-01

    highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we...... measured oxygen-isotope ratios (delta O-18) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (delta N-15: delta C-13) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in delta N-15 and delta O-18 values...

  2. Cell-specific information processing in segregating populations of Eph receptor ephrin-expressing cells

    DEFF Research Database (Denmark)

    Jørgensen, Claus; Sherman, Andrew; Chen, Ginny I

    2009-01-01

    Cells have self-organizing properties that control their behavior in complex tissues. Contact between cells expressing either B-type Eph receptors or their transmembrane ephrin ligands initiates bidirectional signals that regulate cell positioning. However, simultaneously investigating how...... information is processed in two interacting cell types remains a challenge. We implemented a proteomic strategy to systematically determine cell-specific signaling networks underlying EphB2- and ephrin-B1-controlled cell sorting. Quantitative mass spectrometric analysis of mixed populations of EphB2......- and ephrin-B1-expressing cells that were labeled with different isotopes revealed cell-specific tyrosine phosphorylation events. Functional associations between these phosphotyrosine signaling networks and cell sorting were established with small interfering RNA screening. Data-driven network modeling...

  3. Effect of CYP2C9, VKORC1, CYP4F2 and GGCX genetic variants on warfarin maintenance dose and explicating a new pharmacogenetic algorithm in South Indian population.

    Science.gov (United States)

    Krishna Kumar, Dhakchinamoorthi; Shewade, Deepak Gopal; Loriot, Marie-Anne; Beaune, Philippe; Balachander, Jayaraman; Sai Chandran, B V; Adithan, Chandrasekaran

    2014-01-01

    To determine the influence of genetic polymorphisms on warfarin maintenance dose and to explicate an algorithm using the pharmacogenetic and clinical factors to determine the maintenance and/or starting dose of warfarin in South Indian patients receiving warfarin therapy. Patients receiving stabilized warfarin therapy (n=257) were included in the study. Single nucleotide polymorphisms (SNPs) of CYP2C9 (rs1799853 and rs1057910), VKORC1 (rs9923231, rs7196161, rs2884737, rs9934438, rs8050894, rs2359612 and rs7294), CYP4F2 (rs2108622) and GGCX (rs11676382) were genotyped by the quantitative real time-PCR method. The mean daily maintenance dose of warfarin was found to be 4.7 ± 2.1 mg/day. Patients with the CYP2C9*1/*2, *1/*3 and *2/*3 variant genotypes required a 51.0 (2.8 mg), 60.9 (2.3 mg) and 62.2 % (2.2 mg) lower daily maintenance dose of warfarin, respectively, than those patients with the CYP2C9*1/*1 wild-type genotype (5.2 mg) (pgenetic variants of CYP2C9, VKORC1 and GGCX were associated with decreased warfarin dose, except for rs7196161, rs7294 and rs2108622 which were associated with an increased warfarin dose. Genetic variations of CYP2C9 (*2 and *3), VKORC1 (rs9923231, rs7294, rs9934438 and rs2359612), CYP4F2, GGCX and non-genetic factors such as age, body weight, clinical status (post mechanical valve replacement) could explain up to 62.1 % of the overall variation (adjusted r (2) 60.2 %, pGenetic polymorphisms of CYP2C9, VKORC1, CYP4F2 and GGCX are important predictive factors of warfarin maintenance dose, and the developed algorithm will be useful to predict the required maintenance and/or starting warfarin dose in South Indian populations.

  4. Resistance to Plasmopara viticola in a grapevine segregating population is associated with stilbenoid accumulation and with specific host transcriptional responses

    Directory of Open Access Journals (Sweden)

    Delledonne Massimo

    2011-08-01

    revealed that they belong to the categories defense response, photosynthesis, primary and secondary metabolism, signal transduction and transport. Conclusions This study reports the results of a combined metabolic and transcriptional profiling of a grapevine population segregating for resistance to P. viticola. Some resistant individuals were identified and further characterized at the molecular level. These results will be valuable to future grapevine breeding programs.

  5. Use of microsatellite markers in molecular analysis of segregating populations of papaya (Carica papaya L.) derived from backcrossing.

    Science.gov (United States)

    Pinto, F O; Pereira, M G; Luz, L N; Cardozo, D L; Ramos, H C C; Macedo, C M P

    2013-07-08

    Brazil is the world leader in papaya production. However, only a small number of cultivars are registered for commercial planting, mainly owing to delays in obtaining cultivars and the high costs of the field phase of breeding programs. These costs can be reduced when molecular tools are combined with conventional breeding methods. In the present study, we conducted a molecular analysis of a self-fertilized population of a first backcrossing generation of BC1S1 papaya plants via microsatellite markers both to monitor the level of homozygosity and the gene/allele transfer that confers the Golden trait (fruit color) and to assess the parental genomic proportion in the genotypes studied. Based on the analysis of 20 polymorphic microsatellite loci, 19 genotypes with the Golden trait belonging to BC1S1 were evaluated in addition to the parental genotypes. Genetic distance was estimated through weighted index. The genotypes were then grouped using the hierarchical nearest neighbor method, and the analysis of principal coordinates was used to measure the proportion of parental genomes in the segregating genotypes. The mean value of the inbreeding coefficient was 0.36. The analysis of the principal coordinates revealed that on average, 64% of the recurrent parent genome was present in the population. Together, the analyses allowed the selection of 3 individuals for the next backcross cycle (33BC1S1-18, 34BC1S1-16, and 37BC1S1-10). These individuals had a higher proportion of the recurrent parent and were grouped close to the recurrent parent in the cluster analysis.

  6. Genome-wide association study for rib eye muscle area in a Large White×Minzhu F2 pig resource population

    Institute of Scientific and Technical Information of China (English)

    GUO Yun-yan; ZHANG Long-chao; WANG Li-xian; LIU Wen-zhong

    2015-01-01

    Rib eye muscle area (REMA) is an economicaly important trait and one of the main selection criteria for breeding in the swine industry. In the genome-wide association study (GWAS), the Ilumina PorcineSNP60 BeadChip containing 62163 single nucleotide polymorphisms (SNPs) was used to genotype 557 pigs from a porcine Large White×Minzhu intercross population. The REMA (at the 5th–6th, 10th–11th and the last ribs) was measured after slaughtered at the age of (240±7) d for each animal. Association tests between REMA trait and SNPs were performedvia the Genome-Wide Rapid Asso-ciation using the Mixed Model and Regression-Genomic Control (GRAMMAR-GC) approach. From the Ensembl porcine database, SNP annotation was implemented usingSus scrofa Build 10.2. Thirty-three SNPs on SSC12 and 3 SNPs on SSC2 showed signiifcant association with REMA at the last rib at the chromosome-wide signiifcance level. None of the SNPs of REMA at the 5th–6th rib and only a few numbers of the SNPs of REMA at the 10th–11th ribs were found in this study. The Haploview V3.31 program and the Haplo.Stats R package were used to detect and visualize haplotype blocks and to analyze the association of the detected haplotype blocks with REMA at the last rib. A linkage analysis revealed that 4 haplotype blocks contained 4, 4, 2, and 4 SNPs, respectively. Annotations from pig reference genome suggested 2 genes (NOS2,NLK) in block 1 (266 kb), one gene (TMIGD1) in block 2 (348 kb), and one gene (MAP2K4) in block 3 (453 kb). A functional analysis indicated thatMYH3andMYH13 genes are the potential genes controling REMA at the last rib. We screened several candidate intervals and genes based on the SNPs location and the gene function, and inferred thatNOS2 and NLK genes maybe the main genes of REMA at the last ribs.

  7. Mapping in an apple (Malus x domestica) F1 segregating population based on physical clustering of differentially expressed genes.

    Science.gov (United States)

    Jensen, Philip J; Fazio, Gennaro; Altman, Naomi; Praul, Craig; McNellis, Timothy W

    2014-04-04

    Apple tree breeding is slow and difficult due to long generation times, self-incompatibility, and complex genetics. The identification of molecular markers linked to traits of interest is a way to expedite the breeding process. In the present study, we aimed to identify genes whose steady-state transcript abundance was associated with inheritance of specific traits segregating in an apple (Malus × domestica) rootstock F1 breeding population, including resistance to powdery mildew (Podosphaera leucotricha) disease and woolly apple aphid (Eriosoma lanigerum). Transcription profiling was performed for 48 individual F1 apple trees from a cross of two highly heterozygous parents, using RNA isolated from healthy, actively-growing shoot tips and a custom apple DNA oligonucleotide microarray representing 26,000 unique transcripts. Genome-wide expression profiles were not clear indicators of powdery mildew or woolly apple aphid resistance phenotype. However, standard differential gene expression analysis between phenotypic groups of trees revealed relatively small sets of genes with trait-associated expression levels. For example, thirty genes were identified that were differentially expressed between trees resistant and susceptible to powdery mildew. Interestingly, the genes encoding twenty-four of these transcripts were physically clustered on chromosome 12. Similarly, seven genes were identified that were differentially expressed between trees resistant and susceptible to woolly apple aphid, and the genes encoding five of these transcripts were also clustered, this time on chromosome 17. In each case, the gene clusters were in the vicinity of previously identified major quantitative trait loci for the corresponding trait. Similar results were obtained for a series of molecular traits. Several of the differentially expressed genes were used to develop DNA polymorphism markers linked to powdery mildew disease and woolly apple aphid resistance. Gene expression profiling

  8. Selection strategies of segregant soybean populations for resistance to Asian rust Estratégias de seleção de populações segregantes de soja para resistência à ferrugem-asiática

    Directory of Open Access Journals (Sweden)

    Aliny Simony Ribeiro

    2009-11-01

    Full Text Available The objective of this work was to identify the best selection strategies for the more promising parental combinations to obtain lines with good resistance to soybean Asian rust (Phakopsora pachyrhizi. Two experiments were carried out in the field during the 2006/2007 and 2007/2008 growing seasons, to determine the percentage of infected leaf area of individual plants of five parents and their segregant F2 and F3 populations. The data obtained indicates that additive genetic variance predominates in the control of soybean resistance to Asian rust, and that the year and time of assessment do not significantly influence the estimates of the genetic parameters obtained. The narrow-sense heritability (h²r ranged from 23.12 to 55.83%, and indicates the possibility of successful selection of resistant individuals in the early generations of the breeding program. All the procedures used to select the most promising populations to generate superior inbred lines for resistance to P. pachyrhizi presented similar results and identified the BR01-18437 x BRS 232 population as the best for inbred line selection.O objetivo deste estudo foi identificar as estratégias mais eficientes para selecionar as combinações parentais mais promissoras e obter linhas com bom grau de resistência à ferrugem-asiática da soja (Phakopsora pachyrhizi. Dois experimentos foram realizados em campo nos anos agrícolas 2006/2007 e 2007/2008, para avaliar a percentagem da área foliar infectada em plantas individuais de cinco parentais e das suas populações segregantes F2 e F3. Os dados obtidos indicam que a variância genética aditiva predomina no controle da resistência da soja à ferrugem-asiática e que os anos e as épocas de avaliação não influenciaram significativamente as estimativas dos parâmetros genéticos obtidos. A herdabilidade no sentido restrito (h²r variou de 23,12 a 55,83%, o que indica a possibilidade de sucesso com a seleção de indiv

  9. Effect of Environment and Genetic Recombination on Subspecies and Economic Trait Differentiation in the F2 and F3 Generations from indica-japonica Hybridization

    Institute of Scientific and Technical Information of China (English)

    WANG He-tong; XU Zheng-jin; JIN Feng; JIANG Yi-jun; LIN Qing-shan; XU Hai; CHENG Ling; XIA Ying-jun; LIU Chun-xiang; CHEN Wen-fu

    2014-01-01

    indica and japonica are the two most important subspecies of Asian cultivated rice. Identifying mechanisms responsible for population differentiation in these subspecies is important for indica-japonica hybridization breeding. In this study, subspecies and economic trait differentiation patterns were analyzed using morphological and molecular (InDel and Intron Length Polymorphism) data in F2 and F3 populations derived from indica-japonica hybridization. Populations were grown in Liaoning and Guangdong provinces, China, with F3 populations generated from F2 populations using bulk harvesting (BM) and single-seed descent methods (SSD). Segregation distortion was detected in F3-BM populations, but not in F3-SSD or in F2 populations. Superior performance was observed with respect to economic traits in Liaoning compared with that in Guangdong and 1 000-grain weight (KW), seed setting rate (SSR) and grain yield per plant (GYP) were signiifcantly correlated with indica and japonica subspecies types. Analysis of molecular and morphological data demonstrated that the environment is the main factor giving rise to population differentiation in indica-japonica hybridization. In addition, we also found that KW, SSR and GYP are related to subspecies characteristics and kinship, which is possibly a signiifcant factor resulting in economic trait differentiation and determining environmental adaptability. Our study has provided new insights into the process of population differentiation in these subspecies to inform indica-japonica hybridization breeding.

  10. THE SEGREGATION PATTERN OF INSECT RESISTANCE GENES IN THE PROGENIES AND CROSSES OF TRANSGENIC ROJOLELE RICE

    Directory of Open Access Journals (Sweden)

    Satoto Satoto

    2016-10-01

    Full Text Available Successful application of genetic transformation technique, especially in developing rice variety resistant to brown plant hopper and stem borer, will depend on transgene being expressed and the gene inherited in a stable and predictable manner. This study aimed to analyse transgene segregation pattern of the progenies and the crosses of transgenic rice cv. Rojolele harboring cry1Ab and gna genes. The third generation (T2 of fivetransgenic Rojolele events containing gna and/or cry1Ab were evaluated for two generations to identify the homozygous lines and to study their inheritance. The homozygous lines were selected based on the result of PCR technique. The segregation patterns of gna and cry1Ab were studied in eight F2 populations derived from Rojolele x transgenic Rojolele homozygous for cry1Ab and or gna and their reciprocal crosses. Data  resulted from PCR of F2 population were analysed using a Chi Square test. The study obtained six homozygous lines for gna, namely A22- 1-32, A22-1-37, C72-1-9, F11-1-48, K21-1-39, K21-1-48, and two homozygous lines for cry1Ab, namely K21-1-39 and K21- 1-48. Both cry1Ab and gna transgenes had been inherited through selfing and crossing with their wild type as indicated from the F1 containing gna and cry1Ab as many as 48.4% and 47.4%, respectively. In six of the eight crosses, gna was inherited in a 3:1 ratio consistent with Mendelian inheritance of a single dominant locus, while in the remaining two crosses, gna was segregated in a 1:1 ratio. The presence of cry1Ab in F2 populations also showed a 3:1 segregation ratio in all crosses. In the F2 population derived from F1 plant containing cry1Ab and gna, both transgenes segregated in a 9:3:3:1 dihybrid segregation ratio. This study will add to the diversity of genetic sources for insect resistance and allow further use of these transgenic lines for pyramiding resistance to brown plant hopper and stem borer or  separately in rice breeding programs whenever

  11. Yield evaluation of fourteen populations of climbing bean (Phaseolus vulgaris L. segregating lines with anthracnose (Colletotrichum lindemuthianum resistance genes

    Directory of Open Access Journals (Sweden)

    Pachón Nelson A.

    2009-04-01

    Full Text Available

    Common bean is an important low cost and easy access protein source for the Andean region population. Fourteen ‘Bola roja’ and ‘Cargamanto’ climbing bean populations resulting from hybridizing six different regional varieties with anthracnose resistant genotype G2333, were evaluated under greenhouse conditions. With the aim of assessing yield of these hybrids, a completely randomized design was applied for the comparison of the following parameters: 100-seeed weight, number of grains per pod, and number of pods per plant. Te latter was found to be the most important yield indicator. Te study also allowed determining the best evaluated genotypes, which are currently still segregating. Terefore, it is recommended to continue developing line RC1F3.

  12. Electron attachment to F2

    Science.gov (United States)

    McCorkle, D. L.; Christophorou, L. G.; Christodoulides, A. A.; Pichiarella, L.

    1986-08-01

    The rate constant ka for electron attachment to F2 has been measured at ambient (298 K) temperature T in the buffer gas Ar over the mean electron energy range 0.40-2.95 eV; similar measurements were made at T=233, 298, and 373 K in the buffer gas N2 over the range 0.04-0.75 eV. The ka() function attains a maximum value of 1.7×10-8 cm3 s-1 (T=298 K) at ˜0.04 eV and decreases monotonically with increasing above thermal energy; the magnitude of ka increases only slightly with increasing T. The ka() data at 298 K were unfolded and the resultant cross section σa(ɛ) shows a main maximum at ˜0.0 eV, a shoulder at ˜0.5 eV, and a weak maximum at ˜1.1 eV. Possible electron attachment processes are discussed to account for the energy dependence of σa(ɛ). Also discussed, in the light of the present measurements, are published experimental and theoretical results on ka() and σa(ɛ).

  13. Segregated phases in pulmonary surfactant membranes do not show coexistence of lipid populations with differentiated dynamic properties

    DEFF Research Database (Denmark)

    Bernardino de la Serna, Jorge; Orädd, Greger; Bagatolli, Luis

    2009-01-01

    The composition of pulmonary surfactant membranes and films has evolved to support a complex lateral structure, including segregation of ordered/disordered phases maintained up to physiological temperatures. In this study, we have analyzed the temperature-dependent dynamic properties of native...... surfactant membranes and membranes reconstituted from two surfactant hydrophobic fractions (i.e., all the lipids plus the hydrophobic proteins SP-B and SP-C, or only the total lipid fraction). These preparations show micrometer-sized fluid ordered/disordered phase coexistence, associated with a broad...... from the two types of surfactant hydrophobic extract. These latter results suggest that lipid dynamics are similar in the coexisting fluid phases observed by fluorescence microscopy. Additionally, it is found that surfactant proteins significantly reduce the average intramolecular lipid mobility...

  14. Gender Segregation in the Spanish Labor Market: An Alternative Approach

    Science.gov (United States)

    del Rio, Coral; Alonso-Villar, Olga

    2010-01-01

    The aim of this paper is to study occupational segregation by gender in Spain, which is a country where occupational segregation explains a large part of the gender wage gap. As opposed to previous studies, this paper measures not only overall segregation, but also the segregation of several population subgroups. For this purpose, this paper uses…

  15. Análisis del comportamiento de poblaciones segregantes en la primera generación de autogamia de híbridos comerciales de tomate Lycopersicon esculentum Mill Analysis of segregatinf F2 selfed populations in comercial tomato hybrids

    Directory of Open Access Journals (Sweden)

    Baena García Diosdado

    1992-12-01

    Full Text Available

    Se evaluaron las manifestaciones heteróticas en la primera generación de autogamia de cuatro híbridos comerciales de tomate. Los ensayos se realizaron en el Centro Experimental de la Universidad Nacional, Seccional Palmira. Los cuatro híbridos fueron seleccionados por su buen desempeño agronómico, los cuales se compararon con dos líneas avanzadas F6 y una variedad comercial de gran aceptación entre los agricultores. El trabajo se justificó debido a los altos costos de la semilla híbrida importada de tomate tipo-Milano, factor limitante para su empleo a nivel de pequeños agricultores. Las plántulas (F2, híbridos, líneas y variedad se sometieron al sistema de doble trasplante. Cuando las plántulas tenían 10 días se midieron descriptores cuantitativos como longitud del hipocotilo y área de las hojas cotiledonares. Antes de que las plantas se llevaran al vivero definitivo (campo, se hicieron lecturas individuales de altura de planta, diámetro basal, diámetro intermedio y longitud de la tercera hoja. Los resultados arrojaron rendimientos similares entre plantas F2 e híbridos, lo cual abre la posibilidad de usar la semilla F2 como una alternativa de bajo costo para los pequeños agricultores, comparada con la semilla híbrida.

    The heterotic expressions in the first generation of autogamy of 4 commercial tomato hybrids were evaluated. The trial was conducted at the Agronomy School of the National University - Palmira. The four hybrids were chosen for their good agronomic characteristics and were compared with a well known commercial variety. This is justificied for the high cost for the Milano-type tomate hybrid seed limits its use among small fanners. The plantlets (F2, Hybrids, lines and variety were transplanted twice. The experimental materials were evaluated using plantet quantitative traits such as hypocotil length and cotiledonary leaf area, at 10 days. Plant heigh, basal steam diameter, mean steam diameter and

  16. Depth distributionthe of linear codes over ring F2+uF2+U2F2.%环F2+uF2+u2F2上线性码的深度分布

    Institute of Scientific and Technical Information of China (English)

    梁华

    2011-01-01

    记R=F2+uF2+u2F2,定义了环R上码字的深度以及R上线性码的深度分布,研究了环R上码字深度的性质,给出了计算环R上码字深度的递归算法.利用环R上的线性码C及其生成矩阵,得到了域F2上的线性码C1,Cu,Cu2及相应的生成矩阵.通过域F2上的线性码C1,Cu,Cu2之间的关系,讨论了环R上的线性码的深度谱和深度分布,进而得到R上一类线性码的深度分布.%LetR=F2+uF2+u2+u2F2 ,the depth of a codeword and the depth distribution of linear codes over ring R are defined,a number of properties of the depth of codewords are studied, and the recursive algorithm for computing the depth of a codeword is given. Based on the linear codes over R and their generator matrices, the linear codes C1, Cu, Cu2 over F2 and their generator matrices are obtained. By using the relationship of C1, Cu, Cu2, the depth distribution and the depth spectrum of linear codes over R are discussed,moreover the depth distribution of a class of linear code over R is showed.

  17. Main: TE2F2NTPCNA [PLACE

    Lifescience Database Archive (English)

    Full Text Available TE2F2NTPCNA S000397 05-November-2005 (last modified) kehi te2f-2 found in the promoter of tobacco PCN...riptional activation in actively dividing cells and tissue; E2F; PCNA; meristematic tissue; cell cycle; tobacco (Nicotiana tabacum) ATTCCCGC ...

  18. Analysis of recombination QTLs, segregation distortion, and epistasis for fitness in maize multiple populations using ultra-high-density markers

    Science.gov (United States)

    Understanding the maize genomic features would be useful for the study of genetic diversity and evolution and for maize breeding. Here, we used two maize nested association mapping (NAM) populations separately derived in China (CN-NAM) and the US (US-NAM) to explore the maize genomic features. The t...

  19. Population bulk segregant mapping uncovers resistance mutations and the mode of action of a chitin synthesis inhibitor in arthropods

    NARCIS (Netherlands)

    Van Leeuwen, T.; Demaeght, P.; Osborne, E.J.; Dermauw, W.; Gohlke, S.; Nauen, R.; Grbić, M.; Tirry, L.; Merzendorfer, H.; Clark, R.M.

    2012-01-01

    Because of its importance to the arthropod exoskeleton, chitin biogenesis is an attractive target for pest control. This point is demonstrated by the economically important benzoylurea compounds that are in wide use as highly specific agents to control insect populations. Nevertheless, the target

  20. On sumsets in ${\\Bbb F}_2^n$

    CERN Document Server

    Jia, Chaohua

    2012-01-01

    Let ${\\Bbb F}_2$ be the finite field of two elements, ${\\Bbb F}_2^n$ be the vector space of dimension $n$ over ${\\Bbb F}_2$. For sets $A,\\,B\\subseteq{\\Bbb F}_2^n$, their sumset is defined as the set of all pairwise sums $a+b$ with $a\\in A,\\,b\\in B$. Ben Green and Terence Tao proved that, let $K\\geq 1$, if$A,\\,B\\subseteq{\\Bbb F}_2^n$ and $|A+B|\\leq K|A|^{1\\over 2}|B|^{1\\over 2}$, then there exists a subspace $H\\subseteq{\\Bbb F}_2^n$ with $$ |H|\\gg\\exp(-O(\\sqrt{K}\\log K))|A| $$ and $x,\\,y\\in{\\Bbb F}_2^n$ such that $$ |A\\cap(x+H)|^{1\\over 2}|B\\cap(y+H)|^{1\\over 2}\\geq{1\\over 2K}|H|. $$ In this note, we shall use the method of Green and Tao with some modification to prove that if $$ |H|\\gg\\exp(-O(\\sqrt{K}))|A|, $$ then the above conclusion still holds true.

  1. Mechanisms for chromosome segregation.

    Science.gov (United States)

    Bouet, Jean-Yves; Stouf, Mathieu; Lebailly, Elise; Cornet, François

    2014-12-01

    Bacteria face the problem of segregating their gigantic chromosomes without a segregation period restricted in time and space, as Eukaryotes do. Segregation thus involves multiple activities, general or specific of a chromosome region and differentially controlled. Recent advances show that these various mechanisms conform to a “pair and release” rule, which appears as a general rule in DNA segregation. We describe the latest advances in segregation of bacterial chromosomes with emphasis on the different pair and release mechanisms.

  2. Hepameta-- prevalence of hepatitis B/C and metabolic syndrome in population living in separated and segregated Roma settlements: a methodology for a cross-sectional population-based study using community-based approach.

    Science.gov (United States)

    Gecková, Andrea Madarasová; Jarcuska, Peter; Mareková, Mária; Pella, Daniel; Siegfried, Leonard; Jarcuska, Pavol; Halánová, Monika

    2014-03-01

    Roma represent one of the largest and oldest minorities in Europe. Health of many of them, particularly those living in settlements, is heavily compromised by poor dwelling, low educational level, unemployment, and poverty rooted in generational poverty, segregation and discrimination. The cross-sectional population-based study using community based approach aimed to map the prevalence of viral hepatitis B/C and metabolic syndrome in the population living in separated and segregated Roma settlements and to compare it with the occurrence of the same health indicators in the majority population, considering selected risk and protective factors of these health indicators. The sample consisted of 452 Roma (mean age = 34.7; 35.2% men) and 403 non-Roma (mean age = 33.5; 45.9% men) respondents. Data were collected in 2011 via questionnaire, anthropometric measures and analysed blood and urine samples. A methodology used in the study as well as in the following scientific papers is described in the Methods section (i.e. study design, procedures, samples, methods including questionnaire, anthropometric measurements, physical measurements, blood and urine measurements). There are regions of declining prosperity due to high unemployment, long-term problems with poverty and depleted resources. Populations living in these areas, i.e. in Central and Eastern Europe in Roma settlements, are at risk of poverty, social exclusion and other factors affecting health. Therefore, we should look for successful long-term strategies and tools (e.g. Roma mediators, terrain work) in order to improve the future prospects of these minorities.

  3. Detection of single nucleotide polymorphisms associated with ultrasonic backfat depth in a segregating Meishan x White Composite population.

    Science.gov (United States)

    Kuehn, L A; Rohrer, G A; Nonneman, D J; Thallman, R M; Leymaster, K A

    2007-05-01

    Multiple genomic scans have identified QTL for backfat deposition across the porcine genome. The objective of this study was to detect SNP and genomic regions associated with ultrasonic backfat. A total of 74 SNP across 5 chromosomes (SSC 1, 3, 7, 8, and 10) were selected based on their proximity to backfat QTL or to QTL for other traits of interest in the experimental population. Gilts were also genotyped for a SNP thought to influence backfat in the thyroxine-binding globulin gene (TBG) on SSC X. Genotypic data were collected on 298 gilts, divided between the F8 and F10 generations of the US Meat Animal Research Center Meishan resource population (composition, one-quarter Meishan). Backfat depths were recorded by ultrasound from 3 locations along the back at approximately 210 and 235 d of age in the F8 and F10 generations, respectively. Ultrasound measures were averaged for association analyses. Regressors for additive, dominant, and parent-of-origin effects of each SNP were calculated using genotypic probabilities computed by allelic peeling algorithms in GenoProb. The association model included the fixed effects of scan date and TBG genotype, the covariates of weight and SNP regressors, and random additive polygenic effects to account for genetic similarities between animals not explained by known genotypes. Variance components for polygenic effects and error were estimated using MTDFREML. Initially, each SNP was fitted (once with and once without parent-of-origin effects) separately due to potential multi-collinearity between regressions of closely linked markers. To form a final model, all significant SNP across chromosomes were included in a common model and were individually removed in successive iterations based on their significance. Across all analyses, TBG was significant, with an additive effect of approximately 1.2 to 1.6 mm of backfat. Three SNP on SSC3 remained in the final model even though few studies have identified QTL for backfat on this

  4. Organ specificity and transcriptional control of metabolic routes revealed by expression QTL profiling of source--sink tissues in a segregating potato population

    Directory of Open Access Journals (Sweden)

    Kloosterman Bjorn

    2012-02-01

    Full Text Available Abstract Background With the completion of genome sequences belonging to some of the major crop plants, new challenges arise to utilize this data for crop improvement and increased food security. The field of genetical genomics has the potential to identify genes displaying heritable differential expression associated to important phenotypic traits. Here we describe the identification of expression QTLs (eQTLs in two different potato tissues of a segregating potato population and query the potato genome sequence to differentiate between cis- and trans-acting eQTLs in relation to gene subfunctionalization. Results Leaf and tuber samples were analysed and screened for the presence of conserved and tissue dependent eQTLs. Expression QTLs present in both tissues are predominantly cis-acting whilst for tissue specific QTLs, the percentage of trans-acting QTLs increases. Tissue dependent eQTLs were assigned to functional classes and visualized in metabolic pathways. We identified a potential regulatory network on chromosome 10 involving genes crucial for maintaining circadian rhythms and controlling clock output genes. In addition, we show that the type of genetic material screened and sampling strategy applied, can have a high impact on the output of genetical genomics studies. Conclusions Identification of tissue dependent regulatory networks based on mapped differential expression not only gives us insight in tissue dependent gene subfunctionalization but brings new insights into key biological processes and delivers targets for future haplotyping and genetic marker development.

  5. Molecular Dynamics Simulations for Melting Temperatures of SrF2and BaF2

    Institute of Scientific and Technical Information of China (English)

    Xiao-yu Huang; Xin-lu Cheng; Chao-lei Fan; Qiong Chen; Xiao-li Yuan

    2009-01-01

    The shell-model molecular dynamics method was applied to simulate the melting temper-atures of SrF2 and BaF2 at elevated temperatures and high pressures. The same method was used to calculate the equations of state for SrF2 and BaF2 over the pressure range of 0.1 MPa-3 GPa and 0.1 MPa-7 GPa. Compared with previous results for equations of state, the maximum errors are 0.3% and 2.2%, respectively. Considering the pre-melting in the fluorite-type crystals, we made the necessary corrections for the simulated melting temper-atures of SrF2 and BaF2. Consequently, the melting temperatures of SrF2 and BaF2 were obtained for high pressures. The melting temperatures of SrF2 and BaF2 that were obtained by the simulation are in good agreement with available experimental data.

  6. On the evolutionary stability of Mendelian segregation.

    Science.gov (United States)

    Ubeda, Francisco; Haig, David

    2005-07-01

    We present a model of a primary locus subject to viability selection and an unlinked locus that causes sex-specific modification of the segregation ratio at the primary locus. If there is a balanced polymorphism at the primary locus, a population undergoing Mendelian segregation can be invaded by modifier alleles that cause sex-specific biases in the segregation ratio. Even though this effect is particularly strong if reciprocal heterozygotes at the primary locus have distinct viabilities, as might occur with genomic imprinting, it also applies if reciprocal heterozygotes have equal viabilities. The expected outcome of the evolution of sex-specific segregation distorters is all-and-none segregation schemes in which one allele at the primary locus undergoes complete drive in spermatogenesis and the other allele undergoes complete drive in oogenesis. All-and-none segregation results in a population in which all individuals are maximally fit heterozygotes. Unlinked modifiers that alter the segregation ratio are unable to invade such a population. These results raise questions about the reasons for the ubiquity of Mendelian segregation.

  7. Behavior of foF2 and hmF2 after sunset

    Science.gov (United States)

    Danilov, A. D.; Vanina-Dart, L. B.

    2010-12-01

    The time behavior of the foF2 and hmF2 values at the time moment T(ss + 2 h) 2 h after sunset is considered. It is assumed that at this moment, the horizontal winds in the thermosphere in the strongest way influence hmF2 and, therefore, foF2. It is found that a fairly well pronounced and statistically significant change (trend) is observed for the foF2(ss + 2)/ foF2(14) ratio, the sign of the change being different for different stations and even different seasons at the same station. A similar picture is obtained for the value of hmF2(ss + 2). It is shown that a positive correlation between the trends of these two values is observed. This confirms the initial concept of the paper that the foF2 and hmF2 trends are caused by long-term trends in the thermospheric dynamics.

  8. Measuring segregation: an activity space approach.

    Science.gov (United States)

    Wong, David W S; Shaw, Shih-Lung

    2011-06-01

    While the literature clearly acknowledges that individuals may experience different levels of segregation across their various socio-geographical spaces, most measures of segregation are intended to be used in the residential space. Using spatially aggregated data to evaluate segregation in the residential space has been the norm and thus individual's segregation experiences in other socio-geographical spaces are often de-emphasized or ignored. This paper attempts to provide a more comprehensive approach in evaluating segregation beyond the residential space. The entire activity spaces of individuals are taken into account with individuals serving as the building blocks of the analysis. The measurement principle is based upon the exposure dimension of segregation. The proposed measure reflects the exposure of individuals of a referenced group in a neighborhood to the populations of other groups that are found within the activity spaces of individuals in the referenced group. Using the travel diary data collected from the tri-county area in southeast Florida and the imputed racial-ethnic data, this paper demonstrates how the proposed segregation measurement approach goes beyond just measuring population distribution patterns in the residential space and can provide a more comprehensive evaluation of segregation by considering various socio-geographical spaces.

  9. Patterns of residential segregation

    CERN Document Server

    Louf, Rémi

    2015-01-01

    The spatial distribution of income shapes the structure and organisation of cities and its understanding has broad societal implications. Despite an abundant literature, many issues remain however unclear: there is no clear definition of what segregation is, no unambiguous definition of income classes, no clear way to identify neighborhoods, and no method to deal with the polycentric organization of large cities. In this paper, we address all these questions within a unique theoretical framework. We assume that households belonging to the same class tend to live close to each other, and households from different classes tend to avoid one another. Applied to the US 2000 Census Income data, 3 distinct classes emerge from the clustering of the original 16 income classes. Using these unambiguously defined classes, we cluster together contiguous similar areas and find that the number of clusters for each category scales with the city population, an effect that is more pronounced for rich households. Finally, using...

  10. Quantitative Trait Loci Mapping for Bacterial Blight Resistance in Rice Using Bulked Segregant Analysis

    Directory of Open Access Journals (Sweden)

    Xueying Han

    2014-07-01

    Full Text Available Oryza meyeriana is highly resistant to rice bacterial blight (BB and this resistance trait has been transferred to cultivated rice (O. sativa using asymmetric somatic hybridization. However, no resistance genes have yet been cloned. In the present study, a progeny of the somatic hybridization with high BB resistance was crossed with a rice cultivar with high BB susceptibility to develop an F2 population. Using bulked segregant analysis (BSA, 17 polymorphic markers that were linked to rice BB resistance were obtained through scanning a total of 186 simple sequence repeats (SSR and sequence-tagged site (STS markers, evenly distributed on 12 chromosomes. A genetic linkage map was then constructed based on the 17 linkage markers and the F2 segregating population, which was followed by mapping for quantitative trait loci (QTLs for BB resistance. Three QTLs were identified on chromosomes 1, 3 and 5, respectively, and the alleles of the resistant parent at any of the QTLs increased BB resistance. All of the three QTLs had a strong effect on resistance, explaining about 21.5%, 12.3% and 39.2% of the resistance variance, respectively. These QTLs were different from the loci of the BB resistance genes that have been identified in previous studies. The QTLs mapped in this work will facilitate the isolation of novel BB resistance genes and their utilization in rice resistance breeding.

  11. Genomic mapping of social behavior traits in a F2 cross derived from mice selectively bred for high aggression

    Directory of Open Access Journals (Sweden)

    Perkins James

    2010-12-01

    Full Text Available Abstract Background Rapid response to selection was previously observed in mice selected for high levels of inter-male aggression based on number of attacks displayed in a novel social interaction test after isolation housing. Attack levels in this high aggression line (NC900 increased significantly within just four generations of selective breeding, suggesting the presence of a locus with large effect. We conducted an experiment using a small (n ≈ 100 F2 cross between the ICR-derived, non-inbred NC900 strain and the low aggression inbred strain C57BL/6J, genotyped for 154 fully informative SNPs, to determine if a locus with large effect controls the high-aggression selection trait. A second goal was to use high density SNP genotyping (n = 549,000 in the parental strains to characterize residual patterns of heterozygosity within NC900, and evaluate regions that are identical by descent (IBD between NC900 and C57BL/6J, to determine what impacts these may have on accuracy and resolution of quantitative trait locus (QTL mapping in the F2 cross. Results No evidence for a locus with major effect on aggressive behavior in mice was identified. However, several QTL with genomewide significance were mapped for aggression on chromosomes 7 and 19 and other social behavior traits on chromosomes 4, 7, 14, and 19. High density genotyping revealed that 28% of the genome is still segregating among the six NC900 females used to originate the F2 cross, and that segregating regions are present on every chromosome but are of widely different sizes. Regions of IBD between NC900 and C57BL/6J are found on every chromosome but are most prominent on chromosomes 10, 16 and X. No significant differences were found for amounts of heterozygosity or prevalence of IBD in QTL regions relative to global analysis. Conclusions While no major gene was identified to explain the rapid selection response in the NC900 line, transgressive variation (i.e. where the allele from the C57

  12. Preliminary results on correlation in daily f0F2 and M(3000F2 variations

    Directory of Open Access Journals (Sweden)

    Y Nissopoulos

    1994-06-01

    Full Text Available A statistical analysis of the hourly daily values of the factor M(3000F2 and the F2-layer critical frequency f0F2 is carried out first for each hour of the day through-out a given month of a given year at a given station (hour-to-hour variation and then for each day of a given month and year at a given station (day-to-day variation. This analysis shows that these ionospheric characteristics are poorly correlated. It is concluded that the daily values of the first characteristic cannot be estimated from the second by using a simple linear equation.

  13. Bacterial chromosome segregation.

    Science.gov (United States)

    Possoz, Christophe; Junier, Ivan; Espeli, Olivier

    2012-01-01

    Dividing cells have mechanisms to ensure that their genomes are faithfully segregated into daughter cells. In bacteria, the description of these mechanisms has been considerably improved in the recent years. This review focuses on the different aspects of bacterial chromosome segregation that can be understood thanks to the studies performed with model organisms: Escherichia coli, Bacillus subtilis, Caulobacter crescentus and Vibrio cholerae. We describe the global positionning of the nucleoid in the cell and the specific localization and dynamics of different chromosomal loci, kinetic and biophysic aspects of chromosome segregation are presented. Finally, a presentation of the key proteins involved in the chromosome segregation is made.

  14. Viability effects and not meoitic drive cause dramatic departures from Mendelian inheritance for malic enzyme in hybrids of Tigriopus californicus populations.

    Science.gov (United States)

    Willett, C S; Berkowitz, J N

    2007-05-01

    The genetic basis of post-zygotic reproductive isolation is beginning to be untangled in closely related species, but less is known about the genetics of reproductive isolation between divergent populations. Here, two genes encoding malic enzyme (ME) are isolated from the copepod Tigriopus californicus and their influence upon lowered viability in F(2) hybrids of genetically divergent populations is determined. Each ME gene has diverged extensively between T. californicus populations and one gene shows evidence for a recent selective sweep. Segregation patterns of genotypes for both ME genes in adult F(2) hybrids reveal dramatic departures from Mendelian inheritance, deviations that are not seen in F(2) nauplii implying that selection is acting during development based upon the genotype at these ME genes. These results imply that selection against deleterious gene combinations and not aberrant segregation (i.e. meiotic drive) is likely to lead to dramatic departures from Mendelian inheritance observed in these crosses.

  15. Identification of Co-Segregating RAPD Marker Linked to Powdery Mildew Resistance Gene Pm 18 in Wheat

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-li; GU Feng; LI Tao; GAO Ju-rong; WANG Hong-gang

    2004-01-01

    The Pm18 gene of wheat confers resistance to the powdery mildew which is oneof the most serious diseases in many regions of the world. In this study, bulked segregant analysis (BSA) was used to develop randomly amplified polymorphic DNA (RAPD) markers linked to Pml8 gene. Three hundred and twenty decamer primers were screened and one of them was identified as RAPD marker (S411600) linked to Pml8. Using the F2 mapping population from the cross Pml8 × Chancellor, the marker S411600 was shown to co-segregate with the gene Pml8. This marker can be conveniently used for marker-assisted selection in wheat breeding programs for the identification or pyramiding of Pml8 with other resistance genes.

  16. A Segregating Inversion Generates Fitness Variation in Yellow Monkeyflower (Mimulus guttatus).

    Science.gov (United States)

    Lee, Young Wha; Fishman, Lila; Kelly, John K; Willis, John H

    2016-04-01

    Polymorphic chromosomal rearrangements can bind hundreds of genes into single genetic loci with diverse effects. Rearrangements are often associated with local adaptation and speciation and may also be an important component of genetic variation within populations. We genetically and phenotypically characterize a segregating inversion (inv6) in the Iron Mountain (IM) population of Mimulus guttatus (yellow monkeyflower). We initially mapped inv6 as a region of recombination suppression in three F2 populations resulting from crosses among IM plants. In each case, the F1 parent was heterozygous for a derived haplotype, homogenous across markers spanning over 5 Mb of chromsome 6. In the three F2 populations, inv6 reduced male and female fitness components. In addition,i nv6 carriers suffered an ∼30% loss of pollen viability in the field. Despite these costs, inv6 exists at moderate frequency (∼8%) in the natural population, suggesting counterbalancing fitness benefits that maintain the polymorphism. Across 4 years of monitoring in the field, inv6 had an overall significant positive effect on seed production (lifetime female fitness) of carriers. This benefit was particularly strong in harsh years and may be mediated (in part) by strong positive effects on flower production. These data suggest that opposing fitness effects maintain an intermediate frequency, and as a consequence, inv6 generates inbreeding depression and high genetic variance. We discuss these findings in relation to the theory of inbreeding depression and the maintenance of fitness variation.

  17. Testing sexual segregation and aggregation: old ways are best.

    Science.gov (United States)

    Bonenfant, Christophe; Gaillard, Jean-michel; Dray, Stéphane; Loison, Anne; Royer, Manuela; Chessel, Daniel

    2007-12-01

    The study of sexual segregation has received increasing attention over the last two decades. Several hypotheses have been proposed to explain the existence of sexual segregation, such as the "predation risk hypothesis," the "forage selection hypothesis," and the "activity budget hypothesis." Testing which hypothesis drives sexual segregation is hampered, however, by the lack of consensus regarding a formal measurement of sexual segregation. By using a derivation of the well-known chi-square (here called the sexual segregation and aggregation statistic [SSAS]) instead of existent segregation coefficients, we offer a reliable way to test for temporal variation in the occurrence of sexual segregation and aggregation, even in cases where a large proportion of animals are observed alone. A randomization procedure provides a test for the null hypothesis of independence of the distributions of males and females among the groups. The usefulness of SSAS in the study of sexual segregation is demonstrated with three case studies on ungulate populations belonging to species with contrasting life histories and annual grouping patterns (isard, red deer, and roe deer). The existent segregation coefficients were unreliable since, for a given value, sexual segregation could or could not occur. Similarly, the existent segregation coefficients performed badly when males and females aggregated. The new SSAS was not prone to such limitations and allowed clear conclusions regarding whether males and females segregate, aggregate, or simply mix at random applicable to all species.

  18. 白色杜洛克×二花脸F2资源群体中催乳素(PRL)和催乳素受体(PRLR)基因与母猪杀婴行为和产仔数关联性研究%Associations of Porcine Prolactin(PRL)and Prolactin Receptor(PRLR)with Sow Maternal Infanticide Behavior and Litter Size in a White Duroc × Erhualian F2 Resource Population

    Institute of Scientific and Technical Information of China (English)

    陈从英; 朱万成; 李平华; 魏娜; 郭源梅; 高军

    2010-01-01

    [目的]研究PRL、PRLR基因在白色杜洛克×二花脸F2资源群体中的遗传变异及其与母猪杀婴行为和产仔数的关联性.[方法]PRL基因的g.1317T>A、g.8905C>T、g.9056C>T位点,PRLR基因的g.1217C>T、g.1283C>A,g.14396>A、g.1528G>A和g.1600T>A位点采用SNaPshot法对资源群体所有F0、F1和288头F2母猪进行基因型判定,分别利用传递不平衡检测(TDT)和最小二乘法分析这些位点与母猪杀婴行为和产仔性状的关联性.[结果]TDT分析发现,PRL和PRLR基因所有检测SNP位点,无论基因型还是单倍型均与母猪杀婴行为无显著相关.与母猪产仔数相关性分析表明:PRLR基因5个SNP位点的基因型及单倍型与总产仔数、产活仔数、产死胎数、断奶仔猪数和断奶窝重均未达到显著相关;PRL基因的3个SNP位点与母猪的总产仔数和产活仔数达到显著相关(P<0.05),单倍型ACC个体的总产仔数(P=0.0005)和产活仔数(P=0.001)极显著低于其它单倍型个体;单倍型TTT个体的产活仔数显著高于其它单倍型个体(P=0.003).[结论]白色杜洛克×二花脸F2资源群体中,PRL、PRLR基因与母猪杀婴行为无关联性,PRL基因与母猪总产仔、产活仔数显著相关.

  19. Magnetic Excitations of Mixed CoF2/ZnF2 Crystals

    DEFF Research Database (Denmark)

    Cowley, R. A.; Dietrich, O. W.; Jones, D. A.

    1975-01-01

    The magnetic excitations in mixed crystals of Co1-cZncF2 with c=0.14+or-0.02, 0.31+or-0.03 and 0.77+or-0.10 have been measured using neutron inelastic scattering techniques. The results for the first two crystals show that the excitations decrease in frequency with increasing zinc concentration...... and also have a finite lifetime. For the crystal containing the largest concentration of ZnF2 well defined magnetic excitations were not observed. These results are very similar to the predictions of the virtual lattice model in which each exchange interaction of CoF2 is reduced by the concentration of CoF...

  20. Predição do potencial genético de populações segregantes de arroz de terras altas Prediction of genetic potential of segregating upland rice population

    Directory of Open Access Journals (Sweden)

    Patrícia Guimarães Santos

    2001-04-01

    Full Text Available O objetivo deste trabalho foi avaliar o método de Jinks & Pooni na predição do potencial genético de populações segregantes de arroz e estudar o efeito da interação populações segregantes x ambiente na seleção destas populações. Utilizaram-se 23 populações segregantes de arroz de terras altas e duas testemunhas, avaliadas em um látice 5x5, com três repetições, no ano agrícola de 1996/97. O estudo foi conduzido em dois locais em Minas Gerais, Lavras e Patos de Minas, em três épocas distintas de semeadura. Os resultados encontrados em relação à probabilidade de extrair linhagens superiores a um determinado padrão indicaram como mais promissoras as populações CNAx 5496 e CNAx 6001, e menos promissoras, CNAx 6063 e CNAx 6102. A previsão do potencial genético das populações segregantes a partir do método de Jinks & Pooni mostrou-se uma alternativa viável na escolha das populações mais promissoras, permitindo ao melhorista concentrar maiores esforços na avaliação das famílias superiores. A ocorrência das interações populações segregantes x épocas e locais x épocas mostraram a importância de se avaliar as populações em mais de um ambiente. A escolha das populações que apresentam um comportamento estável frente às oscilações ambientais é importante dentro de um programa de melhoramento.This work aimed to evaluate the Jinks & Pooni's method to predict genetic potential of the segregating upland rice population and to study the effect of the segregating population x environment interaction in the selection of those populations. In this work 23 segregating populations of upland rice with two checks were used. They were evaluated in a5x5 lattice, with three replicates, in the agricultural year of 1996/97. The populations were conducted in two sites in Minas Gerais State, Brazil, Lavras and Patos de Minas, at three distinct sowing times. The results found in relation to the probability of extracting

  1. Seleção efetiva para o caráter número de afilhos em populações segregantes de trigo Selection eficiency for tillerning in segregating wheat populations

    Directory of Open Access Journals (Sweden)

    Igor Pirez Valério

    2009-01-01

    Full Text Available O ganho genético obtido com a seleção em gerações segregantes é dependente do cruzamento, das condições experimentais e do caráter alvo de seleção. O objetivo deste trabalho foi determinar o ganho com a seleção em planta espaçada, na geraç��o F2 para número de afilhos, utilizando diferentes critérios de seleção, além de verificar a efetividade destas seleções na geração subseqüente, nos métodos de semeadura deplanta espaçada e linha cheia. As gerações segregantes foram desenvolvidos em 2006 (F2 e 2007 (F2 e F3, sendo a geração F3 avaliada em planta espaçada e linha cheia. Foram empregados três critérios de seleção: a elevado número de afilhos e alta produção de grãos; b reduzido número de afilhos com elevada produção de grãos e c bulk da população. Foram testadas 15 combinações envolvendo genitores com diferente potencial de afilhamento. Os resultados indicam que mesmo em reduzida magnitude, as estimativas de herdabilidade para estimar a média da próxima geração, revelaram eficiência, porém, somente quando as gerações utilizadas foram desenvolvidas em iguais condições de ambiente e manejo. A seleção para elevado ou reduzido número de afilhos e em bulk, foram dependentes do sistema de manejo em que a população segregante tenha sido submetida. A seleção para elevado número de afilhos revelou o maior ganho genético para produção de grãos, porém, a efetividade da seleção em planta espaçada não proporcionou o mesmo comportamento em competição. O melhor desempenho em rendimento de grãos foi detectado na seleção para reduzido número de afilhos, com média elevada para massa de grãos em competição.The genetic gain obtained with the selection in segregating generations depends on the cross, experimental conditions and the target trait selected. The objective of this work was to determine the genetic gain with selection in spaced plants, in the F2 generation for the

  2. Bulk segregant analysis using single nucleotide polymorphism microarrays.

    Directory of Open Access Journals (Sweden)

    Anthony Becker

    Full Text Available Bulk segregant analysis (BSA using microarrays, and extreme array mapping (XAM have recently been used to rapidly identify genomic regions associated with phenotypes in multiple species. These experiments, however, require the identification of single feature polymorphisms (SFP between the cross parents for each new combination of genotypes, which raises the cost of experiments. The availability of the genomic polymorphism data in Arabidopsis thaliana, coupled with the efficient designs of Single Nucleotide Polymorphism (SNP genotyping arrays removes the requirement for SFP detection and lowers the per array cost, thereby lowering the overall cost per experiment. To demonstrate that these approaches would be functional on SNP arrays and determine confidence intervals, we analyzed hybridizations of natural accessions to the Arabidopsis ATSNPTILE array and simulated BSA or XAM given a variety of gene models, populations, and bulk selection parameters. Our results show a striking degree of correlation between the genotyping output of both methods, which suggests that the benefit of SFP genotyping in context of BSA can be had with the cheaper, more efficient SNP arrays. As a final proof of concept, we hybridized the DNA from bulks of an F2 mapping population of a Sulfur and Selenium ionomics mutant to both the Arabidopsis ATTILE1R and ATSNPTILE arrays, which produced almost identical results. We have produced R scripts that prompt the user for the required parameters and perform the BSA analysis using the ATSNPTILE1 array and have provided them as supplemental data files.

  3. Correlations in daily deviations from the median of f0F2, M(3000F2 and VF

    Directory of Open Access Journals (Sweden)

    T. D. Xenos

    1994-06-01

    Full Text Available The statistical analysis of the hourly daily deviations from the corresponding monthly-median values of the factor M(3000F2 and of the critical frequency of the F2-layer, f0F2, reveals that the correlation between these parameters is poor. A similar analysis between the hourly daily deviations from the corresponding monthly-median of the height h’F and the f0F2 leads to similar results. These results indicate that the factor M(3000F2, the height h’F and the critical frequency f0F2 may have a different daily variability.

  4. Commentary: Genger Segregation in Childhood.

    Science.gov (United States)

    Maccoby, Eleanor E.

    1994-01-01

    Provides an overview of the preceding articles in this journal issue. Considers the timing of gender segregation, compatibility between play styles and gender segregation, possible physiological processes underlying gender segregation in play, children's cognitive knowledge about gender, and the consequences of gender segregation. (BAC)

  5. Spectroscopy of laser properties of Nd(3+)-doped CaF2, SrF2, and BaF2

    Science.gov (United States)

    Payne, Stephen A.; Caird, John A.; Chase, L. L.; Smith, L. K.; Nielsen, N. D.; Krupke, William F.

    1990-03-01

    The optical properties of Nd(3+) in CaF2, SrF2, and BaF2 were investigated in order to determine if these materials are useful as laser-pumped amplifier media. The CaF2:Nd crystal was found to not be useful because the impurities tend to cluster at very low concentration, leading to the formation of nonluminescent centers. On the other hand, the Nd(3+) centers in BaF2 exhibit unacceptably low transition strengths. SrF2:Nd appears to have adequate absorption strength, and, in addition, to have a remarkably long emission lifetime of 1280 microns. A maximum doping of 0.20 atomic percent Nd(3+) can be tolerated in SrF2 without the occurrence of detrimental clustering. The peak emission cross section of SrF2:Nd is 1.7 x 10(exp -20) sq cm at 1036.5 nm. Direct measurement of the gain spectrum of SrF2:Nd(3+) reveals the presence of the F-4(sub 3/2) yields G-2(sub 9/2) excited state absorption lines, although the impact on the emission cross section is minor.

  6. Empirical Bayes factor analyses of quantitative trait loci for gestation length in Iberian × Meishan F2 sows.

    Science.gov (United States)

    Casellas, J; Varona, L; Muñoz, G; Ramírez, O; Barragán, C; Tomás, A; Martínez-Giner, M; Ovilo, C; Sánchez, A; Noguera, J L; Rodríguez, M C

    2008-02-01

    The aim of this study was to investigate chromosomal regions affecting gestation length in sows. An experimental F2 cross between Iberian and Meishan pig breeds was used for this purpose and we genotyped 119 markers covering the 18 porcine autosomal chromosomes. Within this context, we have developed a new empirical Bayes factor (BF) approach to compare between nested models, with and without the quantitative trait loci (QTL) effect, and after including the location of the QTL as an unknown parameter in the model. This empirical BF can be easily calculated from the output of a Markov chain Monte Carlo sampling by averaging conditional densities at the null QTL effects. Linkage analyses were performed in each chromosome using an animal model to account for infinitesimal genetic effects. Initially, three QTL were detected at chromosomes 6, 8 and 11 although, after correcting for multiple testing, only the additive QTL located in cM 110 of chromosome 8 remained. For this QTL, the allelic effect of substitution of the Iberian allele increased gestation length in 0.521 days, with a highest posterior density region at 95% ranged between 0.121 and 0.972 days. Although future studies are necessary to confirm if detected QTL is relevant and segregating in commercial pig populations, a hot-spot on the genetic regulation of gestation length in pigs seems to be located in chromosome 8.

  7. Analysis list: F2RL1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available F2RL1 + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/F2RL1.1.tsv htt...p://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/F2RL1.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/F2RL...1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/F2RL1..tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/.gml ...

  8. Understanding Segregation Processes

    Science.gov (United States)

    Bruch, Elizabeth

    There is growing consensus that living in neighborhoods of concentrated poverty increases the likelihood of social problems such as teenage parenthood, drug and alcohol use, crime victimization, and chronic unemployment. Neighborhood inequality is also implicated in studies of enduring race/ethnic health disparities, and there are recent moves to broaden the definition of health care policy to policies targeting social inequality (Mechanic 2007). Residential segregation affects health outcomes in several different ways. First, income, education, and occupation are all strongly related to health (Adler and Newman 2002). Segregation is a key mechanism through which socioeconomic inequality is perpetuated and reinforced, as it hinders the upward mobility of disadvantaged groups by limiting their educational and employment opportunities. Second, segregation increases minority exposure to unhealthy neighborhood environments. Residential segregation creates areas with concentrated poverty and unemployment, both of which are key factors that predict violence and create racial differences in homicide (Samson and Wilson 1995). Neighborhood characteristics, such as exposure to environmental hazards, fear of violence, and access to grocery stores, affect health risks and health behaviors (Cheadle et al. 1991). Tobacco and alcohol industries also advertise their products disproportionately in poor, minority areas (Moore, Williams, and Qualls 1996). Finally, residential segregation leads to inequalitie in health care resources, which contributes to disparities in quality of treatment (Smedley, Stith, and Nelson 2002).

  9. Measuring Inequality and Segregation

    CERN Document Server

    Roberto, Elizabeth

    2015-01-01

    In this paper, I introduce the Divergence Index, a conceptually intuitive and methodologically rigorous measure of inequality and segregation. The index measures the difference between a distribution of interest and another empirical, theoretical, or normative distribution. The Divergence Index provides flexibility in specifying a theoretically meaningful basis for evaluating inequality. It evaluates how surprising an empirical distribution is given a theoretical distribution that represents equality. I demonstrate the unique features of the new measure, as well as deriving its mathematical equivalence with Theil's Inequality Index and the Information Theory Index. I compare the dynamics of the measures using simulated data, and an empirical analysis of racial residential segregation in the Detroit, MI, metro area. The Information Theory Index has become the gold standard for decomposition analyses of segregation. I show that although the Information Theory Index can be decomposed for subareas, it is misleadi...

  10. Cyclic Code and Self-Dual Code over F2+ uF2 + u2F2%环F2+uF2+u2F2上的循环码及自对偶码

    Institute of Scientific and Technical Information of China (English)

    冯倩倩; 周伟刚

    2009-01-01

    We give the structures of a cyclic code over ring R = F2+ uF2 + u2F2 = {0, 1,u, u2,υ,υ2,uυ, υ3}, where υ3 = 0, of odd length and its dual code. For the cyclic code, necessary and sufficient conditions for the existence of self-dual code are provided.

  11. Hardness of CaF2 and BaF2 solid lubricants at 25 to 670 deg C

    Science.gov (United States)

    Deadmore, Daniel L.; Sliney, Harold E.

    1987-01-01

    Plastic deformation is a prominent factor in determining the lubricating value of solid lubricants. Little information is available and its direct measurement is difficult so hardness, which is an indirect measure of this property was determined for fluoride solid lubricant compositions. The Vickers hardness of BaF2 and CaF2 single crystals was measured up to 670 C in a vacuum. The orientation of the BaF2 was near the (013) plane and the CaF2 was about 16 degrees from the degrees from the (1'11) plane. The BaF2 has a hardness of 83 kg/sq mm at the 25 C and 9 at the 600 C. The CaF2 is 170 at 25 C and 13 at 670 C. The decrease in hardness in the temperature range of 25 to 100 C is very rapid and amounts to 40% for both materials. Melts of BaF2 and CaF2 were made in a platinum crucible in ambient air with compositions of 50 to 100 wt% BaF2. The Vickers hardness of these polycrystalline binary compositions at 25 C increased with increasing CaF2 reaching a maximum of 150 kn/sq mm near the eutectic. The polycrystalline CaF2 was 14% softer than that of the single crystal surface and BsF2 was 30% harder than the single crystal surface. It is estimated that the brittle to ductile transition temperature for CaF2 and BaF2 is less than 100 C for the conditions present in the hardness tester.

  12. A Question of Segregation

    DEFF Research Database (Denmark)

    Quedas, Fátima; Ponte, João; Trindade, Carlos

    2016-01-01

    than 40 per cent of breads were indeed over the labelling threshold, and should be labelled. This includes GM maize that is not cultivated in the EU and enters the supply chain via international trade. We conclude that the realisation of coexistence and segregation requires involvement of the full...

  13. Plasmid segregation mechanisms

    DEFF Research Database (Denmark)

    Ebersbach, Gitte; Gerdes, Kenn; Charbon, Gitte Ebersbach

    2005-01-01

    Bacterial plasmids encode partitioning (par) loci that ensure ordered plasmid segregation prior to cell division. par loci come in two types: those that encode actin-like ATPases and those that encode deviant Walker-type ATPases. ParM, the actin-like ATPase of plasmid R1, forms dynamic filaments ...

  14. F2+vF2上线性码的深度谱%ON THE DEPTH SPECTRA OF LINEAR CODES ON RING F2 + vF2

    Institute of Scientific and Technical Information of China (English)

    唐刚

    2012-01-01

    In this paper, the depth distribution and the depth spectra of linear codes over ring R = F2 + νF2 are studied. By using two homomorphisms of Abelian groups from R to F2 and the generator matrices of the codes over R, the upper bound and lower bound of the depth spectra of linear codes of type 4k12k22k3 are obtained.%本文研究了环R=F2+vF2上线性码的深度分布和深度谱.利用环R到F2加群的两个同态映射及R上线性码的生成矩阵,给出了环R上4k12k22k3型线性码的深度谱的上下界.

  15. F2上安全的Edwards曲线%Secure Edwards Curves over F2

    Institute of Scientific and Technical Information of China (English)

    李静; 彭国华

    2009-01-01

    Edwards曲线提供了大量的可以抵挡旁道攻击的椭圆曲线,因此引起了人们特别的关注.最近Bernstein、Lange和Farashahi将一般的Edwards曲线推广到了特征为2的域上,并认为这类椭圆曲线必将会有广泛的应用.但是这类曲线的安全性却仍然是一个值得商榷的问题.文中通过双有理等价映射讨论了F2上的Edwards曲线与Koblitz曲线之间的关系,并由此推出这类Edwards曲线会在一些扩域上具有安全性.%The invention of Edwards curves has attracted much attention from the cryptologists,because they provide a large amount of elliptic curves which are possible to resist the side-channel attack.Recently,Bernstein,Lange and Farashahi generalize Edwards curves to binary field and recommend their wide applications.However,the security of these curves is open to question.In this paper the relation between an ordinary Edwards curve over F2 and one kind of Koblitz curve is discussed,in virtue of the birationally equivalence map,and form this,it is deduced that this Edwards curve is secure in some extension fields.

  16. Main: O2F2BE2S1 [PLACE

    Lifescience Database Archive (English)

    Full Text Available coxin, the maize b-32 genes and the AP-1 pseudopalindrome; O2; opaque-2; be2S1; seed; Brazil nut tree (Bertholletia excelsa) GCCACCTCAT ... ...O2F2BE2S1 S000163 17-May-1998 (last modified) kehi opaque-2 recognition site F2 in Bertholletia excelsa (Bra...zil nut tree) 2S storage protein gene (be2S1); O2 protein binds to F1, F2 and F3 se

  17. Analysis list: Pou3f2 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pou3f2 Embryonic fibroblast,Neural,Pluripotent stem cell + mm9 http://dbarchive.bio...jp/kyushu-u/mm9/colo/Pou3f2.Neural.tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Pou3f2.Pluripoten...e.biosciencedbc.jp/kyushu-u/mm9/colo/Neural.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Pluripotent_stem_cell.gml ...

  18. Difluorophosphoryl nitrene F2P(O)N: matrix isolation and unexpected rearrangement to F2PNO.

    Science.gov (United States)

    Zeng, Xiaoqing; Beckers, Helmut; Willner, Helge; Neuhaus, Patrik; Grote, Dirk; Sander, Wolfram

    2009-12-14

    Triplet difluorophosphoryl nitrene F(2)P(O)N (X(3)A'') was generated on ArF excimer laser irradiation (lambda=193 nm) of F(2)P(O)N(3) in solid argon matrix at 16 K, and characterized by its matrix IR, UV/Vis, and EPR spectra, in combination with DFT and CBS-QB3 calculations. On visible light irradiation (lambda>420 nm) at 16 K F(2)P(O)N reacts with molecular nitrogen and some of the azide is regenerated. UV irradiation (lambda=255 nm) of F(2)P(O)N (X(3)A'') induced a Curtius-type rearrangement, but instead of a 1,3-fluorine shift, nitrogen migration to give F(2)PON is proposed to be the first step of the photoisomerization of F(2)P(O)N into F(2)PNO (difluoronitrosophosphine). Formation of novel F(2)PNO was confirmed with (15)N- and (18)O-enriched isotopomers by IR spectroscopy and DFT calculations. Theoretical calculations predict a rather long P-N bond of 1.922 A [B3LYP/6-311+G(3df)] and low bond-dissociation energy of 76.3 kJ mol(-1) (CBS-QB3) for F(2)PNO.

  19. Applied Thermodynamics: Grain Boundary Segregation

    Directory of Open Access Journals (Sweden)

    Pavel Lejček

    2014-03-01

    Full Text Available Chemical composition of interfaces—free surfaces and grain boundaries—is generally described by the Langmuir–McLean segregation isotherm controlled by Gibbs energy of segregation. Various components of the Gibbs energy of segregation, the standard and the excess ones as well as other thermodynamic state functions—enthalpy, entropy and volume—of interfacial segregation are derived and their physical meaning is elucidated. The importance of the thermodynamic state functions of grain boundary segregation, their dependence on volume solid solubility, mutual solute–solute interaction and pressure effect in ferrous alloys is demonstrated.

  20. Theoretical calculations of the high-pressure phases of ZnF2 and CdF2

    Science.gov (United States)

    Wu, X.; Wu, Z.

    2006-04-01

    First-principles calculations based on density functional theory were used to study the high-pressure phases of both ZnF2 and CdF2. We found that the sequence of the pressure-induced phase transitions is: Rutile (P42/mnm) ↦ CaCl2 (Pnnm) ↦ PdF2 (Pa-3) and CaF2 (Fm3m) ↦ PbCl2 (Pnma) ↦ Ni2In (P63/mmc) for ZnF2 and CdF2 respectively. In ZnF2 the behavior of the ground-state total energy, of the Gibbs free energy and of the lattice constant vs. pressure shown that the phase transition at 4 GPa from the rutile-type phase to the CaCl2-type phase is a second-order phase transition. The mechanism of the structural change was also revealed by the transition from the PbCl2-type phase to the Ni2In-type phase in CdF2. Moreover, the high-pressure behavior of divalent metal fluorides was compared and discussed.

  1. Source Segregation and Collection of Source-Segregated Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Matsufuji, Y.

    2011-01-01

    The Segregation of individual material fractions at the waste source and keeping the fractions separate for collection is one of the key issues in modern waste management. In most cases the waste is just kept segregated from other waste according to certain criteria that improve the possibility...... the more important it is to consider source segregation of the waste, since the amount of waste links to the possibility of obtaining manageable amounts of segregated waste with reasonable logistics as well as to the manpower that can be allocated at the source to perform source segregation of waste....... Therefore, source segregation usually makes most sense in industry, where the waste often also is more well defined and cleaner, while residential waste containing relatively small amounts of each material fraction is a bigger and much more difficult challenge. This chapter describes the main issues...

  2. Patterns of Residential Segregation.

    Directory of Open Access Journals (Sweden)

    Rémi Louf

    Full Text Available The spatial distribution of income shapes the structure and organisation of cities and its understanding has broad societal implications. Despite an abundant literature, many issues remain unclear. In particular, all definitions of segregation are implicitely tied to a single indicator, usually rely on an ambiguous definition of income classes, without any consensus on how to define neighbourhoods and to deal with the polycentric organization of large cities. In this paper, we address all these questions within a unique conceptual framework. We avoid the challenge of providing a direct definition of segregation and instead start from a definition of what segregation is not. This naturally leads to the measure of representation that is able to identify locations where categories are over- or underrepresented. From there, we provide a new measure of exposure that discriminates between situations where categories co-locate or repel one another. We then use this feature to provide an unambiguous, parameter-free method to find meaningful breaks in the income distribution, thus defining classes. Applied to the 2014 American Community Survey, we find 3 emerging classes-low, middle and higher income-out of the original 16 income categories. The higher-income households are proportionally more present in larger cities, while lower-income households are not, invalidating the idea of an increased social polarisation. Finally, using the density-and not the distance to a center which is meaningless in polycentric cities-we find that the richer class is overrepresented in high density zones, especially for larger cities. This suggests that density is a relevant factor for understanding the income structure of cities and might explain some of the differences observed between US and European cities.

  3. Nuclear medium modification of the F2 structure function

    CERN Document Server

    Athar, M Sajjad; Vacas, M J Vicente

    2009-01-01

    We study the nuclear effects in the electromagnetic structure function $F_{2}(x, Q^2)$ in nuclei in the deep inelastic lepton nucleus scattering process by taking into account Fermi motion, binding, pion and rho meson cloud contributions. Calculations have been done in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations for nuclear matter. The ratios $R_{F2}^A(x,Q^2)=\\frac{2F_2^A(x,Q^2)}{AF_{2}^{Deut}(x,Q^2)}$ are obtained and compared with the recent JLAB results for light nuclei that show a non trivial A dependence.

  4. Structure of the house dust mite allergen Der f 2

    DEFF Research Database (Denmark)

    Johannessen, Birthe R; Skov, Lars; Kastrup, Jette S

    2005-01-01

    The X-ray structure of the group 2 major allergen from Dermatophagoides farinae (Der f 2) was determined to 1.83 A resolution. The overall Der f 2 structure comprises a single domain of immunoglobulin fold with two anti-parallel beta-sheets. A large hydrophobic cavity is formed in the interior of...... of Der f 2. Structural comparisons to distantly related proteins suggest a role in lipid binding. Immunoglobulin E (IgE) cross-reactivity between group 2 house dust mite major allergens can be explained by conserved surface areas representing IgE binding epitopes....

  5. General formulae for f1 -> f2 γ

    Science.gov (United States)

    Lavoura, L.

    2003-07-01

    At one-loop level the decay f_1 to f_2 γ, where f1 and f2 are two spin-1/2 particles with the same electric charge, is mediated by a boson B and a spin-1/2 fermion F. The boson B may have either spin - interacting with the fermions through the Dirac matrices 1 and γ_5 - or spin 1 - with V+ A and V- A couplings to the fermions. I give general formulae for the one-loop electroweak amplitude of f_1 to f_2 γ in all these cases.

  6. General formulae for f1 --> f2 gamma

    CERN Document Server

    Lavoura, L

    2003-01-01

    At one-loop level the decay f1 --> f2 gamma, where f1 and f2 are two spin-1/2 particles with the same electric charge, is mediated by a boson B and a spin-1/2 fermion F. The boson B may have either spin 0 - interacting with the fermions through Dirac matrices 1 and gamma5 - or spin 1 - with V+A and V-A couplings to the fermions. I give general formulae for the one-loop electroweak amplitude of f1 --> f2 gamma in all these cases.

  7. Computing the complexity for Schelling segregation models

    Science.gov (United States)

    Gerhold, Stefan; Glebsky, Lev; Schneider, Carsten; Weiss, Howard; Zimmermann, Burkhard

    2008-12-01

    The Schelling segregation models are "agent based" population models, where individual members of the population (agents) interact directly with other agents and move in space and time. In this note we study one-dimensional Schelling population models as finite dynamical systems. We define a natural notion of entropy which measures the complexity of the family of these dynamical systems. The entropy counts the asymptotic growth rate of the number of limit states. We find formulas and deduce precise asymptotics for the number of limit states, which enable us to explicitly compute the entropy.

  8. Chromosome Segregation in Vibrio cholerae

    OpenAIRE

    Ramachandran, R.; Jha, J.; Chattoraj, DK

    2014-01-01

    The study of chromosome segregation is currently one of the most exciting research frontiers in cell biology. In this review, we discuss our current knowledge of the chromosome segregation process in Vibrio cholerae, based primarily on findings from fluorescence microscopy experiments. This bacterium is of special interest because of its eukaryotic feature of having a divided genome, a feature shared with 10% of known bacteria. We also discuss how the segregation mechanisms of V. cholerae com...

  9. Molecular CsF 5 and CsF 2 +

    KAUST Repository

    Rogachev, Andrey Yu.

    2015-06-03

    D5h star-like CsF5, formally isoelectronic with known XeF5− ion, is computed to be a local minimum on the potential energy surface of CsF5, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2F2, or to CsF3 (three isomeric forms)+F2, or for rearrangement to a significantly more stable isomer, a classical Cs+ complex of F5−. Similarly the CsF2+ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

  10. Chromosome segregation in Vibrio cholerae.

    Science.gov (United States)

    Ramachandran, Revathy; Jha, Jyoti; Chattoraj, Dhruba K

    2014-01-01

    The study of chromosome segregation is currently one of the most exciting research frontiers in cell biology. In this review, we discuss our current knowledge of the chromosome segregation process in Vibrio cholerae, based primarily on findings from fluorescence microscopy experiments. This bacterium is of special interest because of its eukaryotic feature of having a divided genome, a feature shared with 10% of known bacteria. We also discuss how the segregation mechanisms of V. cholerae compare with those in other bacteria, and highlight some of the remaining questions regarding the process of bacterial chromosome segregation.

  11. Shaping Segregation: Convexity vs. concavity

    NARCIS (Netherlands)

    Gonzalez, S.; Windows-Yule, C.R.; Luding, S.; Parker, D.J.; Thornton, A.R.

    2014-01-01

    Controlling segregation is both a practical and a theoretical challenge. In this Letter we demonstrate a manner in which rotation-induced segregation may be controlled by altering the geometry of the rotating containers in which granular systems are housed. Using a novel drum design comprising conca

  12. Expressão do fenótipo em populações segregantes de aveia conduzidas em diferentes ambientes Phenotype expression in oat segregant populations under differents environments

    Directory of Open Access Journals (Sweden)

    Volmir Sergio Marchioro

    2003-08-01

    Full Text Available A seleção com base no fenótipo pode ser influenciada por fatores de ambiente, sendo necessário que o melhorista utilize métodos de seleção que separem efeitos genéticos dos de ambiente. O objetivo deste trabalho foi avaliar os componentes do rendimento de populações segregantes de aveia em diferentes métodos de semeadura. Oito populações foram conduzidas em três métodos de semeadura: planta espaçada, cova e linha cheia, em delineamento de blocos casualizados, com duas repetições. Foram selecionadas as panículas com peso superior à média mais um desvio padrão e, a partir destas, obtidos os caracteres peso de grãos e número de grãos por panícula. Os resultados revelaram uma interação significativa das populações com o ambiente. A herdabilidade foi alta, exceto para o caráter número de grãos/panícula na de semeadura em linha cheia. O peso de panícula pode ser um caráter de alta eficiência na seleção de genótipos superiores para o incremento no rendimento de grãos.Selection on the phenotype basis can be affected by environmental factors; forcing the plant-breeder to isolate genetic and environmental factors. The objective of this work was to evaluate the yield components of oat segregant populations subjected to different methods. Eight populations were planted in random block design with two replicates, according to three different models: spaced plant, full line and hill. Panicles with weight higher than mean plus one standard deviation were selected and measured for grain weight and grain number per panicle. Results showed a significant interaction between populations and environmental factors. Heritability was high, excepted for grain number/panicle on the full line models. Panicle weight can be an efficient trait to select genotypes in order to order increase grain yield.

  13. PHOTOELECTRIC PROPERTIES OF PbSe/BaF2/CaF2 FILMS ON Si(111)%硅基PbSe/BaF2/CaF2薄膜及其光电特性

    Institute of Scientific and Technical Information of China (English)

    金进生; 常勇; 等

    2001-01-01

    PbSe films were grown on Si(111) by incorporation of BaF2/CaF2 buffers using molecular beam epitaxy. The measurements of both scanning electronic microscopy and high-resolution X-ray diffraction showed high crystalline quality of the PbSe films. The surface of PbSe was mirror-like and no cracks were observed. The full width at half-maximum of PbSe diffraction peak was only 153 arcsec. The epitaxial PbSe films were used to fabricate photodiodes. For the first time, metallic aluminum was used to form Al-PbSe Schottky diodes, which demonstrated better and more stable current-voltage characteristics than that obtained from Pb-PbSe Schottky diodes.%采用分子束外延方法在Si(111)衬底上生长了PbSe/BaF2/CaF2薄膜,扫描电镜和X-光衍射分析显示,通过生长BaF2/CaF2缓冲层的方法,在Si(111)衬底上外延的PbSe薄膜晶体质量高,PbSe表面光亮,无开裂现象发生,X-光衍射峰峰宽窄(153arcs).外延生长的PbSe薄膜被应用于制作光电二极管,首次采用热蒸发金属铝膜在PbSe表面形成Al-PbSe肖特基结光电二极管,获得了比Pb-PbSe肖特基结更为稳定和理想的电流-电压特性曲线.

  14. The deuteron structure function F2 with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    M. Osipenko; G. Ricco; S. Simula; M. Battaglieri; M. Ripani

    2005-07-01

    The inclusive, inelastic eD scattering cross section has been measured with the CLAS detector in Hall B of the Thomas Jefferson National Accelerator Facility (TJNAF). Combining these data and previously measured world data we have extracted Nachtmann moments of the deuteron structure function F2 in the region 0.4 < Q2 < 100 GeV2/c2. These results are published in hep-ex/0506004. The purpose of the present CLAS-Note is to tabulate the CLAS deuteron F2 data. A description of the data analysis is reported in hep-ex/0506004.

  15. The deuteron structure function F2 with CLAS

    CERN Document Server

    Osipenko, M; Simula, S; Battaglieri, M; Ripani, M; Adams, G; Ambrozewicz, P; Anghinolfi, M; Asavapibhop, B; Asryan, G; Audit, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Batourine, V; Beard, K; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Biselli, A S; Bonner, B E; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Brooks, W K; Bültmann, S; Burkert, V D; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Cazes, A; Chen, S; Cole, P L; Coleman, A; Coltharp, P; Cords, D; Corvisiero, P; Crabb, D; Cummings, J P; De Sanctis, E; De Vita, R; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Empl, A; Eugenio, P; Fatemi, R; Fedotov, G; Feuerbach, R J; Forest, T A; Funsten, H; Garçon, M; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Gordon, C I O; Gothe, R W; Griffioen, K A; Guidal, M; Guillo, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hakobyan, R S; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hu, J; Huertas, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Ito, M M; Jenkins, D; Jo, H S; Joo, K; Jüngst, H G; Kellie, J D; Khandaker, M; Kim, K Y; Kim, K; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Klusman, M; Kossov, M; Kramer, L H; Kubarovski, V; Kühn, J; Kuhn, S E; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Li, J; Lima, A C S; Livingston, K; Lukashin, K; Manak, J J; Marchand, C; McAleer, S; McKinnon, B; McNabb, J W C; Mecking, B A; Mehrabyan, S S; Melone, J J; Mestayer, M D; Meyer, C A; Mikhailov, K; Minehart, R C; Mirazita, M; Miskimen, R; Mokeev, V; Morand, L; Morrow, S A; Müller, J; Mutchler, G S; Nadel-Turonski, P; Napolitano, J; Nasseripour, R; Nefedov, G; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niyazov, R A; Nozar, M; O'Rielly, G V; Ostrovidov, A I; Park, K; Pasyuk, E; Philips, S A; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O I; Polli, E; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Rowntree, D; Rubin, P D; Sabatie, F; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabyan, Yu G; Shaw, J; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Stavinsky, A V; Stepanyan, S; Stokes, B E; Stoler, P; Strauch, S; Suleiman, R; Taiuti, M; Taylor, S; Tedeschi, D J; Thoma, U; Thompson, R; Tkabladze, A; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Zana, L; Zhang, J

    2005-01-01

    The inclusive, inelastic eD scattering cross section has been measured with the CLAS detector in Hall B of the Thomas Jefferson National Accelerator Facility (TJNAF). Combining these data and previously measured world data we have extracted Nachtmann moments of the deuteron structure function F2 in the region 0.4 < Q2 < 100 GeV2/c2. These results are published in hep-ex/0506004. The purpose of the present CLAS-Note is to tabulate the CLAS deuteron F2 data. A description of the data analysis is reported in hep-ex/0506004.

  16. Spin waves in antiferromagnetic FeF2

    DEFF Research Database (Denmark)

    Hutchings, M T; Rainford, B.D.; Guggenheim, H J

    1970-01-01

    Spin-wave dispersion in antiferromagnetic FeF2 has been investigated by inelastic neutron scattering using a chopper time-of-flight spectrometer. The single mode observed has a relatively flat dispersion curve rising from 53 cm-1 at the zone centre to 79 cm-1 at the zone boundary. A spin Hamilton......Spin-wave dispersion in antiferromagnetic FeF2 has been investigated by inelastic neutron scattering using a chopper time-of-flight spectrometer. The single mode observed has a relatively flat dispersion curve rising from 53 cm-1 at the zone centre to 79 cm-1 at the zone boundary. A spin...

  17. Prostaglandin F2alpha elevates blood pressure and promotes atherosclerosis

    DEFF Research Database (Denmark)

    Yu, Ying; Lucitt, Margaret B; Stubbe, Jane

    2009-01-01

    Little is known about prostaglandin F(2alpha) in cardiovascular homeostasis. Prostaglandin F(2alpha) dose-dependently elevates blood pressure in WT mice via activation of the F prostanoid (FP) receptor. The FP is expressed in preglomerular arterioles, renal collecting ducts, and the hypothalamus....... Deletion of the FP reduces blood pressure, coincident with a reduction in plasma renin concentration, angiotensin, and aldosterone, despite a compensatory up-regulation of AT1 receptors and an augmented hypertensive response to infused angiotensin II. Plasma and urinary osmolality are decreased in FP KOs...

  18. Chromosome segregation in plant meiosis

    Science.gov (United States)

    Zamariola, Linda; Tiang, Choon Lin; De Storme, Nico; Pawlowski, Wojtek; Geelen, Danny

    2014-01-01

    Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved. PMID:24987397

  19. Chromosome segregation in plant meiosis

    Directory of Open Access Journals (Sweden)

    Linda eZamariola

    2014-06-01

    Full Text Available Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved.

  20. Source Segregation and Collection of Source-Segregated Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Matsufuji, Y.

    2011-01-01

    of optimal handling of the waste. But in a few cases, the waste must also be separated at source, for example removing the protective plastic cover from a commercial advertisement received by mail, prior to putting the advertisement into the waste collection bin for recyclable paper. These issues are often......The Segregation of individual material fractions at the waste source and keeping the fractions separate for collection is one of the key issues in modern waste management. In most cases the waste is just kept segregated from other waste according to certain criteria that improve the possibility...... termed source separation or sorting at source. Here the word segregation has been chosen to indicate the importance of keeping the waste fractions apart by sorting waste and by separating waste into segregated materials as it is generated. The more waste that a physically defined source generates...

  1. The role of temporal coherence in auditory stream segregation

    DEFF Research Database (Denmark)

    Christiansen, Simon Krogholt

    The ability to perceptually segregate concurrent sound sources and focus one’s attention on a single source at a time is essential for the ability to use acoustic information. While perceptual experiments have determined a range of acoustic cues that help facilitate auditory stream segregation......, it is not clear how the auditory system realizes the task. This thesis presents a study of the mechanisms involved in auditory stream segregation. Through a combination of psychoacoustic experiments, designed to characterize the influence of acoustic cues on auditory stream formation, and computational models...... of auditory processing, the role of auditory preprocessing and temporal coherence in auditory stream formation was evaluated. The computational model presented in this study assumes that auditory stream segregation occurs when sounds stimulate non-overlapping neural populations in a temporally incoherent...

  2. 26 CFR 1.672(f)-2 - Certain foreign corporations.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Certain foreign corporations. 1.672(f)-2 Section... foreign corporations. (a) Application of general rule. Subject to the provisions of paragraph (b) of this... to section 672(f) is a controlled foreign corporation (as defined in section 957), a passive...

  3. The INGV Software for automatic Scaling of foF2 and MUF(3000)F2 from Ionograms

    Science.gov (United States)

    Pezzopane, M.; Scotto, C.

    The INGV software (AUTOSCALA) for automatic scaling of critical frequency f0F2 and MUF(3000)F2 was applied to the ionograms produced by the new Advanced Ionospheric Sounder (AIS-INGV). A test based on large amount of ionograms was performed comparing the automatic scaled parameters with the corresponding ones obtained by the standard manual method. The results of a comparison between the data obtained by AUTOSCALA and ARTIST programs are also shown and particular attention has been paid to the case of a strong ionospheric storm.

  4. Implementing spatial segregation measures in R.

    Directory of Open Access Journals (Sweden)

    Seong-Yun Hong

    Full Text Available Reliable and accurate estimation of residential segregation between population groups is important for understanding the extent of social cohesion and integration in our society. Although there have been considerable methodological advances in the measurement of segregation over the last several decades, the recently developed measures have not been widely used in the literature, in part due to their complex calculation. To address this problem, we have implemented several newly proposed segregation indices in R, an open source software environment for statistical computing and graphics, as a package called seg. Although there are already a few standalone applications and add-on packages that provide access to similar methods, our implementation has a number of advantages over the existing tools. First, our implementation is flexible in the sense that it provides detailed control over the calculation process with a wide range of input parameters. Most of the parameters have carefully chosen defaults, which perform acceptably in many situations, so less experienced users can also use the implemented functions without too much difficulty. Second, there is no need to export results to other software programs for further analysis. We provide coercion methods that enable the transformation of our output classes into general R classes, so the user can use thousands of standard and modern statistical techniques, which are already available in R, for the post-processing of the results. Third, our implementation does not require commercial software to operate, so it is accessible to a wider group of people.

  5. Inherent Segregation in Granular Media

    Directory of Open Access Journals (Sweden)

    Sánchez-Guzmán J.

    2011-10-01

    Full Text Available A study of the inherent segregation within granular media due to the relative size of the different particles is presented. A numerical model is used to simulate granular structures. For both simulation and granular structures evaluations, probability theory is widely used. Particles are idealized by disks (2D model and spheres (3D model. Strictly uniform grain size materials, bimodal (two particle sizes and continuous are simulated. Two variables representing segregation and allowing appreciating the grain-size parameters effects are considered. In uniform materials, the presence of spontaneous structuring is observed. In bimodal and continuous materials, inherent segregation mainly depends on the ratio between maximum and minimum diameters of particle. Some practical implications of inherent segregation in geotechnical problems and other disciplines are remarked.

  6. Can topology reshape segregation patterns?

    CERN Document Server

    Gandica, Yerali; Carletti, Timoteo

    2015-01-01

    We consider a metapopulation version of the Schelling model of segregation over several complex networks and lattice. We show that the segregation process is topology independent and hence it is intrinsic to the individual tolerance. The role of the topology is to fix the places where the segregation patterns emerge. In addition we address the question of the time evolution of the segregation clusters, resulting from different dynamical regimes of a coarsening process, as a function of the tolerance parameter. We show that the underlying topology may alter the early stage of the coarsening process, once large values of the tolerance are used, while for lower ones a different mechanism is at work and it results to be topology independent.

  7. About SnF 2 stannous fluoride. II. Crystal structure of β- and γ-SnF 2

    Science.gov (United States)

    Denes, G.; Pannetier, J.; Lucas, J.

    1980-06-01

    Two new structural modifications (β and γ) of SnF 2 have been prepared and their structures refined from X-ray powder data by analogy with high- and low-pressure TeO 2. Both structures are described and discussed using Galy's and Brown's models. Topological relationships to rutile and cristobalite structures are outlined.

  8. Detection of Distorted Segregation in Genotype of Pollen Calli Derived from Hybrid F1 of Cultivated Rice (Oryza sativa L.) Using SSR Markers

    Institute of Scientific and Technical Information of China (English)

    YAO Yan; LU Yong-gen; LIU Xiang-dong; FENG Jiu-huan; ZHANG Gui-quan

    2006-01-01

    S-a, S-b and S-c are three loci for F1 pollen sterility in cultivated rice (Oryza sativa L.). Taichung 65 (T65) is all Sj/Sj at these three loci, while its F1 pollen sterile near-isogenic lines, TISL2 (S-b), TISL4 (S-a) and TISL5 (S-c) is Si/Si according to their respective sterility locus. Using SSR molecular marker to detect the segregation of the allele Si and Sj in pollen calli population induced from different hybrid F1, which have different pollen sterility locus, showed that the segregation of allele Si and Sj was distorted. The distorted direction of pollen calli population in vitro was not the same as F2 population in vivo. The quantities of pollen callus carrying Sj were much more than that of carrying Si at S-a and S-c locus, the ratio of Si and Sj were 1:4.81 and 1:1.96 respectively. But the opposite tendency was observed at S-b locus, the ratio of Si and Sj being 1:0.35. At the same time, all these results were undisturbed by either culture medium or culture period.

  9. Genetic Load in Sexual and Asexual Diploids: Segregation, Dominance and Genetic Drift

    OpenAIRE

    Haag, Christoph R.; Roze, Denis

    2007-01-01

    In diploid organisms, sexual reproduction rearranges allelic combinations between loci (recombination) as well as within loci (segregation). Several studies have analyzed the effect of segregation on the genetic load due to recurrent deleterious mutations, but considered infinite populations, thus neglecting the effects of genetic drift. Here, we use single-locus models to explore the combined effects of segregation, selection, and drift. We find that, for partly recessive deleterious alleles...

  10. Declining Segregation of Same-Sex Partners: Evidence from Census 2000 and 2010

    OpenAIRE

    Spring, Amy L.

    2013-01-01

    Despite recent media and scholarly attention describing the “disappearance” of traditionally gay neighborhoods, urban scholars have yet to quantify the segregation of same-sex partners and determine whether declining segregation from different-sex partners is a wide-spread trend. Focusing on the 100 most populous places in the United States, I use data from the 2000 and 2010 Decennial Census to examine the segregation of same-sex partners over time and its place-level correl...

  11. Data of evolutionary structure change: 1CLMA-2F2OA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CLMA-2F2OA 1CLM 2F2O A A LTEEQIAEFKEAFALFDKDGDGTITTKELGTVMRSLGQN...PTEAELQDMINEVDADGNGTIDFPEFLSLMARKMKEQDSEEELIEAFKVFDRDGNGLISAAELRHVMTNLGEKLTDDEVDEMIREADIDGDGHINYEEFVRMMVS---... 1CLM A 1CLMA VMTNLGE

  12. Radioactive contamination of BaF2 crystal scintillator

    CERN Document Server

    Polischuk, O G; Bernabei, R; Cappella, F; Caracciolo, V; Cerulli, R; Di Marco, A; Danevich, F A; Incicchitti, A; Poda, D V; Tretyak, V I

    2013-01-01

    Barium fluoride (BaF$_2$) crystal scintillators are promising detectors to search for double beta decay processes in $^{130}$Ba ($Q_{2{\\beta}}$ = 2619(3) keV) and $^{132}$Ba ($Q_{2{\\beta}}$ = 844(1) keV). The $^{130}$Ba isotope is of particular interest because of the indications on 2${\\beta}$ decay found in two geochemical experiments. The radioactive contamination of BaF$_2$ scintillation crystal with mass of 1.714 kg was measured over 113.4 hours in a low-background DAMA/R&D set-up deep underground (3600 m w.e.) at the Gran Sasso National Laboratories of INFN (LNGS, Italy). The half-life of $^{212}$Po (present in the crystal scintillator due to contamination by radium) was estimated as $T_{1/2}$ = 298.8 $\\pm$ 0.8(stat.) $\\pm$ 1.4(syst.) ns by analysis of the events pulse profiles.

  13. Measurements of $F_{2}$ and $xF_{3}^{\

    CERN Document Server

    Yang, U K; Alton, A; Arroyo, C G; Avvakumov, S; De Barbaro, L; De Barbaro, P; Bazarko, A O; Bernstein, R H; Bodek, Arie; Bolton, T; Brau, J E; Buchholz, D; Budd, H S; Bugel, L; Conrad, J; Drucker, R B; Fleming, B T; Formaggio, J A; Frey, R; Goldman, J; Goncharov, M; Harris, D A; Johnson, R A; Kim, J H; King, B J; Kinnel, T; Koutsoliotas, S; Lamm, M J; Marsh, W; Mason, D; McFarland, K S; McNulty, C; Mishra, S R; Naples, D; Suwonjandee, N; Nienaber, P; Romosan, A; Sakumoto, W K; Schellman, H; Sciulli, F J; Seligman, W G; Shaevitz, M H; Smith, W H; Spentzouris, P; Stern, E G; Vaitaitis, A G; Vakili, M; Yu, J; Zeller, G P; Zimmerman, E D

    2001-01-01

    We report on the extraction of the structure functions F_2 and Delta xF_3 = xF_3(nu)-xF_3(nubar) from CCFR nu_mu-Fe and nubar_mu-Fe differential cross sections. The extraction is performed in a physics model independent (PMI) way. This first measurement of Delta xF_3, which is useful in testingmodels of heavy charm production, is higher than current theoretical predictions. The ratio of the F_2(PMI) values measured in nu_mu and nubar_mu scattering is in agreement (within 5%) with the predictions of NLO PDFS using massive charm production schemes, thus resolvin long-standing discrepancy between the two sets of data.

  14. Controlling segregation speed of entangled polymers by the shapes: A simple model for eukaryotic chromosome segregation

    Science.gov (United States)

    Sakai, Yuji; Tachikawa, Masashi; Mochizuki, Atsushi

    2016-10-01

    We report molecular dynamics simulations of the segregation of two overlapping polymers motivated by chromosome segregation in biological cells. We investigate the relationship between polymer shapes and segregation dynamics and show that elongation and compaction make entangled polymers segregate rapidly. This result suggests that eukaryotic chromosomes take such a characteristic rod-shaped structure, which is induced by condensins, to achieve rapid segregation.

  15. BaF2 TIME DIFFERENTIAL PERTURBED ANGULAR DISTRIBUTION SPECTROMETER

    Institute of Scientific and Technical Information of China (English)

    朱升云; 勾振辉; 等

    1994-01-01

    A BaF2 time differential perturbed angular distribution spectrometer has been established at the HI-13 tandem accelerator in CIAE.The time resolution of the spectrometer is 195ps and the nonlinearity is less than 2%.The spectrometer works very stably and no time drift is found over a period of experimental runs.This spectrometer has been successfully used in the g-factor measurement of 43Sc(19/2-,3.1232MeV).

  16. Development of a cw Co : MgF 2 laser

    Science.gov (United States)

    Di Lieto, A.

    2003-03-01

    The results obtained in the development of a cryogenic cw Co : MgF 2 laser, realized at the Dipartimento di Fisica of the Università di Pisa are presented. The laser can be tuned continuously in the range between 1.6 and 2.1 μm, with a typical output power of 1-2 W. A preliminary application to the spectroscopy of a Tm : YLF doped crystal is reported by using a photoacoustic apparatus.

  17. Bulked Segregant Analysis to Detect QTL Related to Heat Tolerance in Rice(Oryza sativa L.)Using SSR Markers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-lian; CHEN Li-yun; XIAO Guo-ying; XIAO Ying-hui; CHEN Xin-bo; ZHANG Shun-tang

    2009-01-01

    The study was undertaken to assess the genetic effect of quantitative trait loci(QTLs)conferring heat tolerance at flowering stage in rice.A population consisting of 279 F2 individuals from the cross between 996,a heat tolerant cultivar and 4628,a heat-sensitive cultivar,was analyzed for their segregation pattern of the difference of seed set rate under optimal temperature condition and high temperature condition.The difference of seed set rate under optimal temperature condition and high temperature condition showed normal distribution,indicating the polygenic control over the trait.To identify main effect of QTL for heat tolerance,the parents were surveyed with 200 primer pairs of simple sequence repeats(SSR).The parental survey revealed 30% polymorphism between parents.In order to detect the main QTL association with heat tolerance,a strategy of combining the DNA pooling from selected segregants and genotyping was adopted.The association of putative markers identified based on DNA pooling from selected segregants was established by single marker analysis(SMA).The results of SMA revealed that SSR markers,RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively.accounted for 17 and 3% of the total variation respectively.The heat tolerance during flowering stage in rice was controlled by multiple gene.The SSR markers,RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively,accounted for 17 and 3% of the total variation respectively.The two genetic loci,especially for RM3735 on chromosome 4,can be used in marker-assistant-selected method in heat tolerance breeding in rice.

  18. Proximate drivers of spatial segregation in non-breeding albatrosses.

    Science.gov (United States)

    Clay, Thomas A; Manica, Andrea; Ryan, Peter G; Silk, Janet R D; Croxall, John P; Ireland, Louise; Phillips, Richard A

    2016-07-21

    Many animals partition resources to avoid competition, and in colonially-breeding species this often leads to divergent space or habitat use. During the non-breeding season, foraging constraints are relaxed, yet the patterns and drivers of segregation both between and within populations are poorly understood. We modelled habitat preference to examine how extrinsic (habitat availability and intra-specific competition) and intrinsic factors (population, sex and breeding outcome) influence the distributions of non-breeding grey-headed albatrosses Thalassarche chrysostoma tracked from two major populations, South Georgia (Atlantic Ocean) and the Prince Edward Islands (Indian Ocean). Spatial segregation was greater than expected, reflecting distinct seasonal differences in habitat selection and accessibility, and avoidance of intra-specific competition with local breeders. Previously failed birds segregated spatially from successful birds during summer, when they used less productive waters, suggesting a link between breeding outcome and subsequent habitat selection. In contrast, we found weak evidence of sexual segregation, which did not reflect a difference in habitat use. Our results indicate that the large-scale spatial structuring of albatross distributions results from interactions between extrinsic and intrinsic factors, with important implications for population dynamics. As habitat preferences differed substantially between colonies, populations should be considered independently when identifying critical areas for protection.

  19. Heats of Segregation and Segregation Profiles of BCC Metals

    Science.gov (United States)

    Good, Brian S.; Bozzolo, Guillermo

    2002-01-01

    The composition of metal alloy surfaces is often different from that of the bulk. Some alloys exhibit surface segregation, where one or more species reside preferentially at or near the surface. A detailed understanding of this behavior is necessary to correctly model such phenomena as adhesion or catalysis. Several phenomenological approaches to the problem have been put forward, falling into two broad categories: Thermodynamic approaches, where the equilibrium distribution of chemical species is computed. Atomistic approaches, where the tendency of a species to segregate is determined by computation of the energies of single atoms of that species in bulk and surface environments.

  20. Upsilon(1S)->gamma+f2'(1525); f2'(1525)->K0sK0s decays

    CERN Document Server

    Besson, D; Pedlar, T K; Cronin-Hennessy, D; Hietala, J; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Xiao, T; Brisbane, S; Martin, L; Powell, A; Spradlin, P; Wilkinson, G; Mendez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Hu, D; Moziak, B; Napolitano, J; Ecklund, K M; Insler, J; Muramatsu, H; Park, C S; Pearson, L J; Thorndike, E H; Yang, F; Ricciardi, S; Thomas, C; Artuso, M; Blusk, S; Mountain, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Lincoln, A; Smith, M J; Zhou, P; Zhu, J; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Randrianarivony, K; Tatishvili, G; Briere, R A; Vogel, H; Onyisi, P U E; Rosner, J L; Alexander, J P; Cassel, D G; Das, S; Ehrlich, R; Fields, L; Gibbons, L; Gray, S W; Hartill, D L; Heltsley, B K; Kreinick, D L; Kuznetsov, V E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Sun, W M; Yelton, J; Rubin, P; Lowrey, N; Mehrabyan, S; Selen, M; Wiss, J; Libby, J; Kornicer, M; Mitchell, R E; Tarbert, C M

    2011-01-01

    We report on a study of exclusive radiative decays of the Upsilon(1S) resonance into a final state consisting of a photon and two K0s candidates. We find evidence for a signal for Upsilon(1S)->gamma f_2'(1525); f_2'(1525)->K0sK0s, at a rate (4.0+/-1.3+/-0.6)x10^{-5}, consistent with previous observations of Upsilon(1S)->gamma f_2'(1525); f_2'(1525)->K+K-, and isospin. Combining this branching fraction with existing branching fraction measurements of Upsilon(1S)->gamma f_2'(1525) and J/psi->gamma f_2'(1525), we obtain the ratio of branching fractions: B(Upsilon(1S)->gamma f_2'(1525))/B(J/psi->gamma f_2'(1525))=0.09+/-0.02, approximately consistent with expectations based on soft collinear effective theory.

  1. NiF2/NaF:CaF2/Ca Solid-State High-Temperature Battery Cells

    Science.gov (United States)

    West, William; Whitacre, Jay; DelCastillo, Linda

    2009-01-01

    Experiments and theoretical study have demonstrated the promise of all-solid-state, high-temperature electrochemical battery cells based on NiF2 as the active cathode material, CaF2 doped with NaF as the electrolyte material, and Ca as the active anode material. These and other all-solid-state cells have been investigated in a continuing effort to develop batteries for instruments that must operate in environments much hotter than can be withstood by ordinary commercially available batteries. Batteries of this type are needed for exploration of Venus (where the mean surface temperature is about 450 C), and could be used on Earth for such applications as measuring physical and chemical conditions in geothermal wells and oil wells. All-solid-state high-temperature power cells are sought as alternatives to other high-temperature power cells based, variously, on molten anodes and cathodes or molten eutectic salt electrolytes. Among the all-solid-state predecessors of the present NiF2/NaF:CaF2/Ca cells are those described in "Solid-State High-Temperature Power Cells" (NPO-44396), NASA Tech Briefs, Vol. 32, No. 5 (May 2008), page 40. In those cells, the active cathode material is FeS2, the electrolyte material is a crystalline solid solution of equimolar amounts of Li3PO4 and LiSiO4, and the active anode material is Li contained within an alloy that remains solid in the intended high operational temperature range.

  2. Joint QTL analysis of three connected F2-crosses in pigs

    Directory of Open Access Journals (Sweden)

    Bennewitz Jörn

    2010-11-01

    Full Text Available Abstract Background Numerous QTL mapping resource populations are available in livestock species. Usually they are analysed separately, although the same founder breeds are often used. The aim of the present study was to show the strength of analysing F2-crosses jointly in pig breeding when the founder breeds of several F2-crosses are the same. Methods Three porcine F2-crosses were generated from three founder breeds (i.e. Meishan, Pietrain and wild boar. The crosses were analysed jointly, using a flexible genetic model that estimated an additive QTL effect for each founder breed allele and a dominant QTL effect for each combination of alleles derived from different founder breeds. The following traits were analysed: daily gain, back fat and carcass weight. Substantial phenotypic variation was observed within and between crosses. Multiple QTL, multiple QTL alleles and imprinting effects were considered. The results were compared to those obtained when each cross was analysed separately. Results For daily gain, back fat and carcass weight, 13, 15 and 16 QTL were found, respectively. For back fat, daily gain and carcass weight, respectively three, four, and five loci showed significant imprinting effects. The number of QTL mapped was much higher than when each design was analysed individually. Additionally, the test statistic plot along the chromosomes was much sharper leading to smaller QTL confidence intervals. In many cases, three QTL alleles were observed. Conclusions The present study showed the strength of analysing three connected F2-crosses jointly. In this experiment, statistical power was high because of the reduced number of estimated parameters and the large number of individuals. The applied model was flexible and was computationally fast.

  3. Grain Boundary Segregation in Metals

    CERN Document Server

    Lejcek, Pavel

    2010-01-01

    Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.

  4. EVALUASI KERAGAMAN GENETIK INDUK IKAN KERAPU SUNU (Plectropomus leopardus F-1 DAN TURUNANNYA (F-2 DENGAN PENANDA mt-DNA

    Directory of Open Access Journals (Sweden)

    Sari Budi Moria Sembiring

    2012-12-01

    pada turunannya (F-2. Hal ini dimungkinkan bahwa yuwana yang dianalisis tersebut berasal dari populasi 3 komposit haplotip induk F-1. Hasil analisis dengan program Tools for Population Genetic Analysis (TFPGA menunjukkan bahwa nilai keragaman genetik induk F-1 mengalami penurunan sebesar 20,46% terhadap turunannya (F-2, hal ini diduga karena sedikitnya jumlah induk efektif yang memijah. Dengan demikian penambahan induk efektif perlu dilakukan untuk menghindari laju penurunan keragaman genetik.

  5. Tailings philosophies : to segregate or not to segregate

    Energy Technology Data Exchange (ETDEWEB)

    Wells, P.S. [Suncor Energy, Fort McMurray, AB (Canada)

    2010-07-01

    Traditional technologies for treating oil sands tailings include the segregation of of tailings when discharged into water-filled ponds. The coarser tailings form long beaches. However, the percentage of silts and clays that remain suspended within the water column pose significant challenges to oil sands operators, and contribute to water losses and increases in storage volume. This paper discussed new technologies developed to identify the tailings materials that contribute to the problem and methods designed to isolate and treat the materials. Treatment material balances, process water balances, and material handling requirements for the technologies were evaluated and compared. Three scenarios were considered: (1) a sub-aqueous beaching scenario where tailings were produced by extraction and pumped to a beach storage area for dewatering through self-drainage; (2) a non-segregated tailings (NST) scenario that used mature fine tailings (MFT) drying; (3) and a segregated stream scenario where MFT drying was used where tailings were deposited in traditional tailings ponds. Results of the study showed that the segregated stream tailings treatment system was preferred to NST treatment system. Options for sub-aerial NST deposition may overcome the volume discrepancies between treating fines as well as the required volumes of coarser materials. 5 refs., 2 tabs., 2 figs.

  6. The $f_2(1810)$ as a triangle singularity

    CERN Document Server

    Xie, Ju-Jun; Oset, Eulogio

    2016-01-01

    We perform calculations showing that a source producing $K^* \\bar{K}^*$ in $J = 2$ and $L=0$ gives rise to a triangle singularity at $1810$ MeV with a width of about $200$ MeV from the mechanism $K^* \\to \\pi K$ and then $K\\bar{K}^*$ merging into the $a_1(1260)$ resonance. We suggest that this is the origin of the present $f_2(1810)$ resonance and propose to look at the $\\pi a_1(1260)$ mode in several reactions to clarify the issue.

  7. The EPSPS Pro106Ser substitution solely accounts for glyphosate resistance in a goosegrass (Eleusine indica) population from Tennessee, United States

    Institute of Scientific and Technical Information of China (English)

    Janel L Huffman; Chance W Riggins; Lawrence E Steckel; Patrick J Tranel

    2016-01-01

    Previous studies have documented the occurrence of glyphosate-resistant (GR) goosegrass (Eleusine indica (L.) Gaertn.) and, in at least some cases, resistance is due to an altered target site. Research was performed to determine if an altered target site was responsible for GR in a Tennessee, United States goosegrass population (TennGR). DNA sequencing revealed a mutation in TennGR plants conferring the Pro106Ser 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) substitution previously identiifed in other GR populations. F2 populations were derived from TennGR plants crossed with plants from a glyphosate-susceptible population (TennGS) and analyzed for their response to glyphosate and genotyped at the EPSPS locus. Plants from the F2 populations segregated 1:2:1 sensitive:intermediate:resistant in response to a selec-tive dose of glyphosate, and these responses co-segregated with the EPSPS genotypes (PP106, PS106, and SS106). To separately investigate the effect of the Pro106Ser substitution on GR, glyphosate dose-response curves and 50% effective dose (ED50) values were compared among the three genotypes and the two parental populations. The SS106 genotype was 3.4-fold resistant relative to the PP106 genotype, identical to the resistance level obtained when comparing the resistant and susceptible parental populations. We conclude that the mutation conferring a Pro106Ser EPSPS mutation is solely responsible for GR in the TennGR goosegrass population.

  8. Sexual orientation, prejudice and segregation

    NARCIS (Netherlands)

    Plug, E.; Webbink, D.; Martin, N.

    2014-01-01

    This article examines whether gay and lesbian workers sort into tolerant occupations. With information on sexual orientation, prejudice, and occupational choice taken from Australian Twin Registers, we find that gays and lesbians shy away from prejudiced occupations. We show that our segregation res

  9. PICH promotes mitotic chromosome segregation

    DEFF Research Database (Denmark)

    Nielsen, Christian Thomas Friberg; Hickson, Ian D

    2016-01-01

    PICH is an SNF2-family DNA translocase that appears to play a role specifically in mitosis. Characterization of PICH in human cells led to the initial discovery of "ultra-fine DNA bridges" (UFBs) that connect the 2 segregating DNA masses in the anaphase of mitosis. These bridge structures, which...

  10. Nonequilibrium Segregation in Petroleum Reservoirs

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1999-01-01

    We analyse adsorption of a multicomponent mixture at high pressure on the basis of the potential theory of adsorption. The adsorbate is considered as a segregated mixture in the external field produced by a solid adsorbent. we derive an analytical equation for the thickness of a multicomponent fi...

  11. Yb:CaF2 thin-disk laser.

    Science.gov (United States)

    Wentsch, Katrin Sarah; Weichelt, Birgit; Günster, Stefan; Druon, Frederic; Georges, Patrick; Abdou Ahmed, Marwan; Graf, Thomas

    2014-01-27

    We present Ytterbium-doped CaF2 as a laser active material with good prospects for high-power operation in thin-disk laser configuration owing to its favorable thermal properties. Thanks to its broad emission bandwidth the material is also suitable for the generation of ultra-short pulses. The properties of the crystal as well as the challenges related to the coating, polishing, mounting and handling processes which are essential to achieve high power laser oscillation in thin-disk configuration are discussed. A wavelength tunability of 92 nm is demonstrated, which confirms the potential of Yb:CaF2 for the generation of ultra-short pulses. An output power of 250 W with an optical efficiency of η opt = 47% was measured in CW multimode thin-disk laser operation with a pump spot diameter of 3.6 mm. Using a smaller pump spot diameter of 1 mm the fundamental mode output power was 13 W with an optical efficiency of η opt = 34%.

  12. The 2009-2012 Ionosonde and IRI2012 Variability of foF 2, hmF 2, M3000F2, B 0, B1 Parameters over Warsaw

    Directory of Open Access Journals (Sweden)

    Szwabowski Michał

    2016-08-01

    Full Text Available This paper presents comparisons of variability and accordance of ionospheric parameters foF2, hmF2, M3000F2, B0, B1 over the middle latitude station in Warsaw (52.21°N, 21.06°E. Examination included observational data from Space Research Centre ionosonde in Poland and International Reference Ionosphere (IRI 2012 model, for the time period of increasing solar activity from 2009 to 2012. The analysis concerned: trend, monthly median differences in twenty-four hours variability, local minima and maxima. Results are presented as tables of semi-annual data, and plots of difference in four-year period. The study indicated good agreement of foF2 and hmF2 parameters. Underestimations of B1 and M3000F2, variability of B0 parameter in Bil-2000, Gul-1987, and ABT-2009 option, were taken into consideration.

  13. Identification of genes and networks driving cardiovascular and metabolic phenotypes in a mouse F2 intercross.

    Directory of Open Access Journals (Sweden)

    Jonathan M J Derry

    Full Text Available To identify the genes and pathways that underlie cardiovascular and metabolic phenotypes we performed an integrated analysis of a mouse C57BL/6JxA/J F2 (B6AF2 cross by relating genome-wide gene expression data from adipose, kidney, and liver tissues to physiological endpoints measured in the population. We have identified a large number of trait QTLs including loci driving variation in cardiac function on chromosomes 2 and 6 and a hotspot for adiposity, energy metabolism, and glucose traits on chromosome 8. Integration of adipose gene expression data identified a core set of genes that drive the chromosome 8 adiposity QTL. This chromosome 8 trans eQTL signature contains genes associated with mitochondrial function and oxidative phosphorylation and maps to a subnetwork with conserved function in humans that was previously implicated in human obesity. In addition, human eSNPs corresponding to orthologous genes from the signature show enrichment for association to type II diabetes in the DIAGRAM cohort, supporting the idea that the chromosome 8 locus perturbs a molecular network that in humans senses variations in DNA and in turn affects metabolic disease risk. We functionally validate predictions from this approach by demonstrating metabolic phenotypes in knockout mice for three genes from the trans eQTL signature, Akr1b8, Emr1, and Rgs2. In addition we show that the transcriptional signatures for knockout of two of these genes, Akr1b8 and Rgs2, map to the F2 network modules associated with the chromosome 8 trans eQTL signature and that these modules are in turn very significantly correlated with adiposity in the F2 population. Overall this study demonstrates how integrating gene expression data with QTL analysis in a network-based framework can aid in the elucidation of the molecular drivers of disease that can be translated from mice to humans.

  14. Race and space in the 1990s: changes in the geographic scale of racial residential segregation, 1990-2000.

    Science.gov (United States)

    Reardon, Sean F; Farrell, Chad R; Matthews, Stephen A; O'Sullivan, David; Bischoff, Kendra; Firebaugh, Glenn

    2009-03-01

    We use newly developed methods of measuring spatial segregation across a range of spatial scales to assess changes in racial residential segregation patterns in the 100 largest U.S. metropolitan areas from 1990 to 2000. Our results point to three notable trends in segregation from 1990 to 2000: (1) Hispanic-white and Asian-white segregation levels increased at both micro- and macro-scales; (2) black-white segregation declined at a micro-scale, but was unchanged at a macro-scale; and (3) for all three racial groups and for almost all metropolitan areas, macro-scale segregation accounted for more of the total metropolitan area segregation in 2000 than in 1990. Our examination of the variation in these trends among the metropolitan areas suggests that Hispanic-white and Asian-white segregation changes have been driven largely by increases in macro-scale segregation resulting from the rapid growth of the Hispanic and Asian populations in central cities. The changes in black-white segregation, in contrast, appear to be driven by the continuation of a 30-year trend in declining micro-segregation, coupled with persistent and largely stable patterns of macro-segregation.

  15. Fine mapping of the rice bacterial blight resistance gene Xa-4 and its co-segregation marker

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An F2 population developed from the Xa-4 near isogenic lines,IR24 and IRBB4,was used for fine mapping of the rice bacterial blight resistance gene,Xa-4.Some restriction fragment length polymorphism (RFLP) markers on the high-density map constructed by Harushima et al.and the amplified DNA fragments homologous to the conserved domains of plant disease resistance (R) genes were used to construct the genetic linkage map around the gene Xa-4 by scoring susceptible individuals in the population.Xa-4 was mapped between the RFLP marker G181 and the polymerase chain reaction (PCR) marker M55.The R gene homologous fragment marker RS13 was found co-segregating with Xa-4 by analyzing all the plants in the population.This result opened an approach to map-based cloning of this gene,and marker RS13 can be applied to molecular marker-assisted selection of Xa-4 in rice breeding programs.

  16. Spatial Boundaries and the Local Context of Residential Segregation

    CERN Document Server

    Roberto, Elizabeth

    2015-01-01

    Spatial boundaries are a defining feature of a city's social and spatial organization. Rivers, highways, and train tracks create excess distance between nearby locations and often mark social separation -- they become dividing lines that are well known to residents. Qualitative studies are rich with insight about the local significance of boundaries, but they have been largely ignored in the quantitative segregation literature. I advance existing scholarship by integrating spatial boundaries into the way we measure residential segregation for city populations. I introduce a new method that measures the proximity of residential locations and the reach of local environments around each location using road distance. This is more realistic than straight line ("as the crow flies") distance, because it captures the connectivity of roads and the distance imposed by physical boundaries. I measure segregation using the Divergence Index, which evaluates how surprising the composition of each local environment is given ...

  17. The Consequences of Chromosome Segregation Errors in Mitosis and Meiosis

    Directory of Open Access Journals (Sweden)

    Tamara Potapova

    2017-02-01

    Full Text Available Mistakes during cell division frequently generate changes in chromosome content, producing aneuploid or polyploid progeny cells. Polyploid cells may then undergo abnormal division to generate aneuploid cells. Chromosome segregation errors may also involve fragments of whole chromosomes. A major consequence of segregation defects is change in the relative dosage of products from genes located on the missegregated chromosomes. Abnormal expression of transcriptional regulators can also impact genes on the properly segregated chromosomes. The consequences of these perturbations in gene expression depend on the specific chromosomes affected and on the interplay of the aneuploid phenotype with the environment. Most often, these novel chromosome distributions are detrimental to the health and survival of the organism. However, in a changed environment, alterations in gene copy number may generate a more highly adapted phenotype. Chromosome segregation errors also have important implications in human health. They may promote drug resistance in pathogenic microorganisms. In cancer cells, they are a source for genetic and phenotypic variability that may select for populations with increased malignance and resistance to therapy. Lastly, chromosome segregation errors during gamete formation in meiosis are a primary cause of human birth defects and infertility. This review describes the consequences of mitotic and meiotic errors focusing on novel concepts and human health.

  18. SOCIAL POLARIZATION AND SEGREGATION IN BEIJING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The biggest change in Beijing during the last decade has been in its social structure. This transition is changing the existing situation of social "equality", and leads to polarization both in individual communities and in society as a whole. As a result, social variations and conflicting interest are growing, and some new social groups are emerging. In this paper we seek to explore a new urban phenomenon in post-1984 Beijing: social polarization and segregation. At first, we will discuss some elements explaining social polarization. The elements and the processes can be traced back to two main aspects of the economic reforms, namely the internal reforms unleashing a huge rural exodus and the open door policy. Special attention will be paid to the new lower end of the social ladder, which is made up largely by rural migrantsthat make up the so-called floating population.Finally we will explore how these social changes translate into urban segregation, with some consideration for future develop-ments.

  19. PLC based Segregation of Scrap Material

    Directory of Open Access Journals (Sweden)

    Mangesh B. Nagapure

    2017-04-01

    Full Text Available This paper describe segregation of scrap materials using automation system. With the growing population rate, the amount of waste being produced is also increasing at a very faster rate. It is also posing a very serious problem at the industrial and domestic level to manage the wastes being dumped everywhere as landfill waste. So, it is very crucial to have some system to manage waste automatically which is currently not there. Prime Minister Modi’s mission of Swaccha Bharat Abhiyan can also be successfully implemented by the proposed system. The paper proposes a novel method where the provision is given to separate out metal and nonmetal waste into respective bins by the sensing of different sensors incorporated along the conveyor belt. Pieces of glass, paper, wood and metallic materials are separated out from proposed work. Using the segregation, most of the metal and nonmetal components like paper, glass, plastic increases the economic value of the waste to its best. For every scrap separation system, a higher level of automation demands more and more accurate programming device. So, we are using programmable logic controller (PLC as main component

  20. 18 CFR 401.113 - Segregable materials.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Segregable materials. 401.113 Section 401.113 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... Segregable materials. Any reasonably segregable portion of a record shall be provided to any person...

  1. International perspectives on countering school segregation

    NARCIS (Netherlands)

    Bakker, J.T.A.; Denessen, E.J.P.G.; Peters, T.J.M.; Walraven, G.

    2010-01-01

    School segregation is perceived as an unyielding problem worldwide, which is manifest along both ethnic and socio-economic lines. With this edited volume we aim to share information about school segregation and policies focused on countering school segregation from an international perspective. Many

  2. Hating the Neighbors: The Role of Hate Crime in the Perpetuation of Black Residential Segregation

    Directory of Open Access Journals (Sweden)

    Ami M. Lynch

    2008-06-01

    Full Text Available Grounded in group conflict theory and the defended neighborhoods thesis, this nationwide empirical study of cities and their residential segregation levels examines the occurrence of hate crime using data for all U.S. cities with populations over 95,000 and Uniform Crime Reporting data for hate crime, in conjunction with 2000 census data. Hate crime is any illegal act motivated by pre-formed bias against, in this case, a person’s real or perceived race. This research asks: Do hate crime levels predict white/black segregation levels? How does hate crime predict different measures of white/black segregation? I use the dissimilarity index measure of segregation operationalized as a continuous, binary, and ordinal variable, to explore whether hate crime predicts segrega- tion of blacks from whites. In cities with higher rates of hate crime there was higher dissimilarity between whites and blacks, controlling for other factors. The segregation level was more likely to be “high” in a city where hate crime occurred. Blacks are continually multiply disadvantaged and distinctly affected by hate crime and residential segregation. Prior studies of residential segregation have focused almost exclusively on individual choice, residents’ lack of finances, or discriminatory actions that prevent racial minorities from moving, to explore the correlates of segregation. Notably absent from these studies are measures reflecting the level of hate crime occurring in cities. This study demonstrates the importance of considering hate crime and neighborhood conflict when contemplating the causes of residential segregation.

  3. Radioluminescence and photoluminescence of Th:CaF$_2$ crystals

    CERN Document Server

    Stellmer, Simon; Schumm, Thorsten

    2015-01-01

    We study thorium-doped CaF$_2$ crystals as a possible platform for optical spectroscopy of the Th-229 nuclear isomer transition. We anticipate two major sources of background signal that might cover the nuclear spectroscopy signal: VUV-photoluminescence, caused by the probe light, and radioluminescence, caused by the radioactive decay of Th-229 and its daughters. We find a rich photoluminescence spectrum at wavelengths above 260 nm, and radioluminescence emission above 220 nm. This is very promising, as fluorescence originating from the isomer transition, predicted at a wavelength shorter than 200 nm, could be filtered spectrally from the crystal luminescence. Furthermore, we investigate the temperature-dependent decay time of the luminescence, as well as thermoluminescence properties. Our findings allow for an immediate optimization of spectroscopy protocols for both the initial search for the nuclear transition using synchrotron radiation, as well as future optical clock operation with narrow-linewidth lase...

  4. Comment on "first accuracy evaluation of NIST-F2"

    CERN Document Server

    Gibble, Kurt

    2015-01-01

    We discuss the treatment of the systematic frequency shifts due to microwave lensing and distributed cavity phase in "First accuracy evaluation of NIST-F2" 2014 Metrologia 51 174-182. We explain that the microwave lensing frequency shift is generally non-zero and finite in the limit of no applied microwave field. This systematic error was incorrectly treated and we find that it contributes a significant frequency offset. Accounting for this shift implies that the measured microwave amplitude dependence (e.g due to microwave leakage) is comparable to the total reported inaccuracy. We also discuss the importance of vertically aligning the fountain perpendicular to the axis of the cavity feeds, when the cavity has only two independent feeds. Finally, we note that background gas collisions have a different behavior for cold clock atoms than for clock atoms at room-temperature, and therefore room temperature measurements do not directly apply to laser-cooled clocks.

  5. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation.

  6. Tests on the molecular structure \\\\of $f_2(1270)$, $f'_2(1525)$ from $\\psi (nS)$ and $\\Upsilon (nS)$ decays

    CERN Document Server

    Dai, Lianrong

    2013-01-01

    Based on previous studies that support the vector-vector molecular structure of the $f_2(1270)$, $f'_2(1525)$, $\\bar{K}^{*\\,0}_2(1430)$, $f_0(1370)$ and $f_0(1710)$ resonances, we make predictions for $\\psi (2S)$ decay into $\\omega(\\phi) f_2(1270)$, $\\omega(\\phi) f'_2(1525)$, $K^{*0}(892) \\bar{K}^{*\\,0}_2(1430)$ and radiative decay of $\\Upsilon (1S),\\Upsilon (2S), \\psi (2S)$ into $\\gamma f_2(1270)$, $\\gamma f'_2(1525)$, $\\gamma f_0(1370)$, $\\gamma f_0(1710)$. Agreement with experimental data is found for three available ratios, without using free parameters, and predictions are done for other cases.

  7. X-ray crystal truncation rod scattering from MBE grown (CaF 2-SrF 2)/Si(111) superlattices

    Science.gov (United States)

    Harada, J.; Itoh, Y.; Shimura, T.; Takahashi, I.; Alvarez, J. C.; Sokolov, N. S.

    1994-01-01

    Flouride CaF 2-SrF 2 superlattices (SLs) grown by molecular beam epitaxy have been studied by means of X-ray diffractometry for the first time. The diffraction patterns showed reasonably good crystalline quality of the SLs and a type-B epitaxial relation to the Si(111) substrate. From the analysis of the crystal truncation rod (CTR) profiles, based on the pseudomorphic model, it was obtained that despite the same high temperature (770°C) of formation of the CaF 2/Si(111) interface its structure depended on the growth temperature of the SLs. The shape of the CTR profiles confirmed the existence of the superlattice which consists of one or two monolayer thick SrF 2 layers. Some CaF 2/SrF 2-interface roughness was noticeable.

  8. Defect-induced wetting on BaF 2(111) and CaF 2(111) at ambient conditions

    Science.gov (United States)

    Cardellach, M.; Verdaguer, A.; Fraxedas, J.

    2011-12-01

    The interaction of water with freshly cleaved (111) surfaces of isostructural BaF2 and CaF2 single crystals at ambient conditions (room temperature and under controlled humidity) has been studied using scanning force microscopy in different operation modes and optical microscopy. Such surfaces exhibit contrasting behaviors for both materials: while on BaF2(111) two-dimensional water layers are formed after accumulation at step edges, CaF2(111) does not promote the formation of such layers. We attribute such opposed behavior to lattice match (mismatch) between hexagonal water ice and the hexagonal (111) surfaces of BaF2(CaF2). Optical microscope images reveal that this behavior also determines the way the surfaces become wetted at a macroscopic level.

  9. Moving Toward Integration? Effects of Migration on Ethnoracial Segregation Across the Rural-Urban Continuum.

    Science.gov (United States)

    Winkler, Richelle L; Johnson, Kenneth M

    2016-08-01

    This study analyzes the impact of migration on ethnoracial segregation among U.S. counties. Using county-level net migration estimates by age, race, and Hispanic origin from 1990-2000 and 2000-2010, we estimate migration's impact on segregation by age and across space. Overall, migration served to integrate ethnoracial groups in both decades, whereas differences in natural population change (increase/decrease) would have increased segregation. Age differences, however, are stark. Net migration of the population under age 40 reduced segregation, while net migration of people over age 60 further segregated people. Migration up and down the rural-urban continuum (including suburbanization among people of color) did most to decrease segregation, while interregional migration had only a small impact. People of color tended to move toward more predominantly white counties and regions at all ages. Migration among white young adults (aged 20-39) also decreased segregation. Whites aged 40 and older, however, showed tendencies toward white flight. Moderate spatial variation suggests that segregation is diminishing the most in suburban and fringe areas of several metropolitan areas in the Northeast and Midwest, while parts of the South, Southwest, and Appalachia show little evidence of integration.

  10. Bacterial Chromosome Organization and Segregation

    OpenAIRE

    Toro, Esteban; Shapiro, Lucy

    2010-01-01

    Bacterial chromosomes are generally ∼1000 times longer than the cells in which they reside, and concurrent replication, segregation, and transcription/translation of this crowded mass of DNA poses a challenging organizational problem. Recent advances in cell-imaging technology with subdiffraction resolution have revealed that the bacterial nucleoid is reliably oriented and highly organized within the cell. Such organization is transmitted from one generation to the next by progressive segrega...

  11. Ethnic Segregation in Arizona Charter Schools

    Directory of Open Access Journals (Sweden)

    Casey D. Cobb

    1999-01-01

    Full Text Available Among the criticisms of charter schools is their potential to further stratify schools along ethnic and class lines. This study addressed whether Arizona charter schools are more ethnically segregated than traditional public schools. In 1996-97, Arizona had nearly one in four of all charter schools in the United States. The analysis involved a series of comparisons between the ethnic compositions of adjacent charter and public schools in Arizona's most populated region and its rural towns. This methodology differed from the approach of many evaluations of charter schools and ethnic stratification in that it incorporated the use of geographic maps to compare schools' ethnic make-ups. The ethnic compositions of 55 urban and 57 rural charter schools were inspected relative to their traditional public school neighbors.

  12. Computation of the chiral condensate using $N_f=2$ and $N_f=2+1+1$ dynamical flavors of twisted mass fermions

    CERN Document Server

    Cichy, Krzysztof; Jansen, Karl; Shindler, Andrea

    2013-01-01

    We apply the spectral projector method, recently introduced by Giusti and L\\"uscher, to compute the chiral condensate using $N_f=2$ and $N_f=2+1+1$ dynamical flavors of maximally twisted mass fermions. We present our results for several quark masses at three different lattice spacings which allows us to perform the chiral and continuum extrapolations. In addition we report our analysis on the $O(a)$ improvement of the chiral condensate for twisted mass fermions. We also study the effect of the dynamical strange and charm quarks by comparing our results for $N_f=2$ and $N_f=2+1+1$ dynamical flavors.

  13. Dynamics and complexity of the Schelling segregation model

    Science.gov (United States)

    Domic, Nicolás Goles; Goles, Eric; Rica, Sergio

    2011-05-01

    In this paper we consider the Schelling social segregation model for two different populations. In Schelling’s model, segregation appears as a consequence of discrimination, measured by the local difference between two populations. For that, the model defines a tolerance criterion on the neighborhood of an individual, indicating wether the individual is able to move to a new place or not. Next, the model chooses which of the available unhappy individuals really moves. In our work, we study the patterns generated by the dynamical evolution of the Schelling model in terms of various parameters or the initial condition, such as the size of the neighborhood of an inhabitant, the tolerance, and the initial number of individuals. As a general rule we observe that segregation patterns minimize the interface of zones of different people. In this context we introduce an energy functional associated with the configuration which is a strictly decreasing function for the tolerant people case. Moreover, as far as we know, we are the first to notice that in the case of a non-strictly-decreasing energy functional, the system may segregate very efficiently.

  14. Neural-network-based prediction techniques for single station modeling and regional mapping of the foF2 and M(3000F2 ionospheric characteristics

    Directory of Open Access Journals (Sweden)

    T. D. Xenos

    2002-01-01

    Full Text Available In this work, Neural-Network-based single-station hourly daily foF2 and M(3000F2 modelling of 15 European ionospheric stations is investigated. The data used are neural networks and hourly daily values from the period 1964- 1988 for training the neural networks and from the period 1989-1994 for checking the prediction accuracy. Two types of models are presented for the F2-layer critical frequency prediction and two for the propagation factor M(3000F2. The first foF2 model employs the E-layer local noon calculated daily critical frequency (foE12 and the local noon F2- layer critical frequency of the previous day. The second foF2 model, which introduces a new regional mapping technique, employs the Juliusruh neural network model and uses the E-layer local noon calculated daily critical frequency (foE12, and the previous day F2-layer critical frequency measured at Juliusruh at noon. The first M(3000F2 model employs the E-layer local noon calculated daily critical frequency (foE12, its ± 3 h deviations and the local noon cosine of the solar zenith angle (cos c12. The second model, which introduces a new M(3000F2 mapping technique, employs Juliusruh neural network model and uses the E-layer local noon calculated daily critical frequency (foE12, and the previous day F2-layer critical frequency measured at Juliusruh at noon.

  15. Distinguishing between MSSM and NMSSM through $\\Delta F=2$ processes

    CERN Document Server

    Kumar, Jacky

    2016-01-01

    We study deviations between MSSM and $Z_3$ -invariant NMSSM, with respect to their predictions in $\\Delta F = 2$ processes. We find that potentially significant effects arise either from the well known double-penguin diagrams, due to the extra scalar NMSSM states, or from neutralino-gluino box contributions, due to the extended neutralino sector. Both are discussed to be effective in the large $tan \\beta$ regime. Enhanced genuine-NMSSM contributions in double penguins are expected for a light singlet spectrum (CP-even,CP-odd), while the magnitude of box effects is primarily controlled through singlino mixing. The latter is found to be typically subleading (but non-negligible) for $\\lambda \\lesssim 0.5$, however it can become dominant for $\\lambda \\sim$ $O(1)$. We also study the low $\\tan \\beta$ regime, where a distinction between MSSM and NMSSM can come instead due to experimental constraints, acting differently on the allowed parameter space of each model. To this end, we incorporate the recent limits from $...

  16. Nucleon isovector couplings from $N_f=2$ lattice QCD

    CERN Document Server

    Bali, Gunnar S; Glässle, Benjamin; Göckeler, Meinulf; Najjar, Johannes; Rödl, Rudolf H; Schäfer, Andreas; Schiel, Rainer W; Söldner, Wolfgang; Sternbeck, Andre

    2014-01-01

    We compute the axial, scalar, tensor and pseudoscalar isovector couplings of the nucleon as well as the induced tensor and pseudoscalar charges in lattice simulations with $N_f=2$ mass-degenerate non-perturbatively improved Wilson-Sheikholeslami-Wohlert fermions. The simulations are carried out down to a pion mass of 150 MeV and linear spatial lattice extents of up to 4.6 fm at three different lattice spacings ranging from approximately 0.08 fm to 0.06 fm. Possible excited state contamination is carefully investigated and finite volume effects are studied. The couplings, determined at these lattice spacings, are extrapolated to the physical pion mass. In this limit we find agreement with experimental results, where these exist, with the exception of the magnetic moment. A proper continuum limit could not be performed, due to our limited range of lattice constants, but no significant lattice spacing dependence is detected. Upper limits on discretization effects are estimated and these dominate the error budget...

  17. 17 CFR 240.17f-2 - Fingerprinting of securities industry personnel.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Fingerprinting of securities industry personnel. 240.17f-2 Section 240.17f-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... Activities § 240.17f-2 Fingerprinting of securities industry personnel. (a) Exemptions for the fingerprinting...

  18. Zinc tolerance and hyperaccumulation in F1 and F2 offspring from intra and interecotype crosses of Thlaspi caerulescens.

    Science.gov (United States)

    Frérot, H; Lefèbvre, C; Petit, C; Collin, C; Dos Santos, A; Escarré, J

    2005-01-01

    The relationship between zinc (Zn) tolerance and hyperaccumulation in Thlaspi caerulescens was investigated from F1 and F2 crosses within and among metallicolous and nonmetallicolous Mediterranean populations. F1 offspring were grown on increasingly Zn-enriched soils to test Zn enrichment effects, and many families of F2 offspring were grown on a Zn-rich soil. Tolerance of F1 offspring depended on stress intensity. Tolerance of interecotype crosses was intermediate between that of the intraecotype crosses. No difference in Zn accumulation appeared among the F1 offspring from the three crosses involving metallicolous parents. Otherwise, none of these offspring exceeded the Zn hyperaccumulation threshold (10,000 mg kg(-1)), unlike the nonmetallicolous ones. The latter also showed the highest mortality. In some F2 families from interecotype crosses, hyperaccumulation values exceeded 15,000 mg kg(-1) in nontolerant offspring, whereas tolerant offspring displayed lower values (c. 10,000 mg kg(-1)). There was no difference between tolerant and nontolerant offspring when they showed low hyperaccumulation. Therefore, the relationship between tolerance and hyperaccumulation in F1 and F2 crosses depended on the hyperaccumulation level of plants.

  19. Sexual segregation in foraging giraffe

    Science.gov (United States)

    Mramba, Rosemary Peter; Mahenya, Obeid; Siyaya, Annetjie; Mathisen, Karen Marie; Andreassen, Harry Peter; Skarpe, Christina

    2017-02-01

    Sexual segregation in giraffe is known to vary between savannas. In this study, we compared sexual segregation in giraffe in one nutrient-rich savanna, the Serengeti National Park, one nutrient-poor, Mikumi National Park, and one medium rich savanna, Arusha National Park, (from here on referred to just by name) based on effects of sexual size dimorphism and related hypotheses. Data were collected in the wet and dry seasons, by driving road transects and making visual observations of browsing giraffe. Additional data were collected from literature (plant chemistry; mammal communities). There was a noticeable difference in browsing by females and males and in browsing between the three savannas. Females browsed a higher diversity of tree species in Serengeti whereas males browsed a higher diversity in Arusha, while the diversity of species browsed in Mikumi was high and about the same in both sexes. Females selected for high concentrations of nitrogen and low concentrations of tannins and phenolics compared to males in Serengeti but selection in Mikumi was more complex. Males browsed higher in the canopy than females in all sites, but the browsing height was generally higher in Serengeti than Mikumi and Arusha. Season had an effect on the browsing height independent of sex in Mikumi, where giraffes browsed higher in the dry season compared to the wet season. Males spent more time browsing per tree compared to females in all three sites; however, browsing time in Mikumi was also affected by season, where giraffes had longer browsing bouts in the wet season compared to the dry season. We suggest that sexual differences in forage requirement and in foraging interacts with differences in tree chemistry and in competing herbivore communities between nutrient rich and nutrient poor savanna in shaping the sexual segregation.

  20. High energy factorization predictions for the charm structure function $F_{2}^{c}$ at HERA

    CERN Document Server

    Munier, S

    1998-01-01

    High energy factorization predictions for F2^c are derived using BFKL descriptions of the proton structure function F2 at HERA. The model parameters are fixed by a fit of F2 at small x. Two different approaches of the non perturbative proton input are shown to correspond to the factorization at the gluon or quark level, respectively. The predictions for F2^c are in agreement with the data within the present error bars. However, the photon wave-function formulation (factorization at quark level) predicts significantly higher F2^c than both gluon factorization and a next-leading order DGLAP model.

  1. Entropy as the driver of chromosome segregation.

    Science.gov (United States)

    Jun, Suckjoon; Wright, Andrew

    2010-08-01

    We present a new physical biology approach to understanding the relationship between the organization and segregation of bacterial chromosomes. We posit that replicated Escherichia coli daughter strands will spontaneously demix as a result of entropic forces, despite their strong confinement within the cell; in other words, we propose that entropy can act as a primordial physical force which drives chromosome segregation under the right physical conditions. Furthermore, proteins implicated in the regulation of chromosome structure and segregation may in fact function primarily in supporting such an entropy-driven segregation mechanism by regulating the physical state of chromosomes. We conclude that bacterial chromosome segregation is best understood in terms of spontaneous demixing of daughter strands. Our concept may also have important implications for chromosome segregation in eukaryotes, in which spindle-dependent chromosome movement follows an extended period of sister chromatid demixing and compaction.

  2. Schelling's Segregation Model: Parameters, scaling, and aggregation

    Directory of Open Access Journals (Sweden)

    Abhinav Singh

    2009-09-01

    Full Text Available Thomas Schelling proposed a simple spatial model to illustrate how, even with relatively mild assumptions on each individual's nearest neighbor preferences, an integrated city would likely unravel to a segregated city, even if all individuals prefer integration. This agent based lattice model has become quite influential amongst social scientists, demographers, and economists. Aggregation relates to individuals coming together to form groups and Schelling equated global aggregation with segregation. Many authors assumed that the segregation which Schelling observed in simulations on very small cities persists for larger, realistic size cities. We describe how different measures could be used to quantify the segregation and unlock its dependence on city size, disparate neighbor comfortability threshold, and population density. We identify distinct scales of global aggregation, and show that the striking global aggregation Schelling observed is strictly a small city phenomenon. We also discover several scaling laws for the aggregation measures. Along the way we prove that as the Schelling model evolves, the total perimeter of the interface between the different agents decreases, which provides a useful analytical tool to study the evolution.

  3. Strong mass segregation around a massive black hole

    CERN Document Server

    Alexander, Tal

    2008-01-01

    We show that the mass-segregation solution for the steady state distribution of stars around a massive black hole (MBH) has two branches: the known weak segregation solution (Bahcall & Wolf 1977), and a newly discovered strong segregation solution, presented here. The nature of the solution depends on the heavy-to-light stellar mass ratio M_H/M_L and on the unbound population number ratio N_H/N_L, through the relaxational coupling parameter \\Delta=4 N_H M_H^2 /[N_L M_L^2(3+M_H/M_L)]. When the heavy stars are relatively common (\\Delta>>1), they scatter frequently on each other. This efficient self-coupling leads to weak mass segregation, where the stars form n \\propto r^{-\\alpha_M} mass-dependent cusps near the MBH, with indices \\alpha_H=7/4 for the heavy stars and 3/2<\\alpha_L<7/4 for the light stars (i.e. \\max(\\alpha_H-\\alpha_L)~=1/4). However, when the heavy stars are relatively rare (\\Delta<<1), they scatter mostly on light stars, sink to the center by dynamical friction and settle into a m...

  4. Validation of the TEC2F2 model over the African equatorial region

    Science.gov (United States)

    Ssessanga, Nicholas

    2016-06-01

    In this paper a statistical method, TEC2F2, of estimating critical F2 layer frequency (foF2) from Global Positioning System (GPS) Vertical Total Electron content (VTEC) is extended from Africa's mid-latitudes to the equatorial region, and the results validated. The equatorial region is one of the most dynamic yet under-represented over Africa in ionospheric studies. The TEC2F2 method was first considered for the South African region (mid-latitudes). This region is covered by a network of ionosondes that provided a validation platform for the TEC2F2 method before being applied to other parts of Africa. The results show that over the African equatorial region, the TEC2F2 method is a potential candidate in more accurately estimating the foF2 parameter than the most recent version of the International Reference Ionosphere (IRI-2012) model.

  5. Perceptual-binding and persistent surface segregation

    OpenAIRE

    2004-01-01

    Visual input is segregated in the brain into subsystems that process different attributes such as motion and color. At the same time, visual information is perceptually segregated into objects and surfaces. Here we demonstrate that perceptual segregation of visual entities based on a transparency cue precedes and affects perceptual binding of attributes. Adding an irrelevant transparency cue paradoxically improved the pairing of color and motion for rapidly alternating surfaces. Subsequent ex...

  6. Effect of cryogenic temperature on spectroscopic and laser properties of Er,La:SrF2-CaF2 crystal

    Science.gov (United States)

    Švejkar, Richard; Šulc, Jan; Němec, Michal; Jelínková, Helena; Doroshenko, Maxim E.; Nakladov, Andrei N.; Osiko, Vjatcheslav V.

    2016-03-01

    The laser and spectroscopic properties of crystal Er,La:SrF2-CaF2 at temperature range 80 - 300 K, which is appropriate for generation of radiation around 2.7 um is presented. The sample of Er,La:SrF2-CaF2 (concentration Er(0.04), La(0.12):Ca(0.77)Sr(0.07)) had plan-parallel face-polished faces without anti-reflection coatings (thickness 8.2 mm). During spectroscopy and laser experiments the Er,La:SrF2-CaF2 was attached to temperature controlled copper holder and it was placed in vacuum chamber. The transmission and emission spectra of Er,La:SrF2-CaF2 together with the fluorescence decay time were measured in dependence on temperature. The excitation of Er,La:SrF2-CaF2 was carried out by a laser diode radiation (pulse duration 5 ms, repetition rate 20 Hz, pump wavelength 973 nm). Laser resonator was hemispherical, 140 mm in length with at pumping mirror (HR @ 2.7 µm) and spherical output coupler (r = 150 mm, R = 95 % @ 2.5 - 2.8 µm). Tunability of laser at 80 K in range 2690 - 2765 nm was obtained using MgF2 birefringent filter. With decreasing temperature of sample the fluorescence lifetime of manifold 4I11/2 (upper laser level) became shorter and intensity of up-conversion radiation was increasing. The highest slope efficiency with respect to absorbed power was 2.3 % at 80 K. The maximum output of peak amplitude power was 0.3 W at 80 K, i.e. 1.5 times higher than measured this value at 300 K. The wavelength generated by Er,La:SrF2-CaF2 laser (2.7 µm) is relatively close to absorption peak of water (3 µm) and so, one of the possible usage should be in medicine and spectroscopy.

  7. Housing Systems and Ethnic Spatial Segregation

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter; Andersson, Roger; Wessel, Terje

    Residential spatial segregation is related to housing markets and housing policies. In this paper, ethnic segregation is compared across four Nordic capitals and explanations for the differences are examined by comparing the housing markets and housing policies of the countries. The housing markets...... of neighbourhoods. Ethnic segmentation of housing tenures thus contributes to segregation, but the effect is much dependent on how tenures are distributed across space. In one of the cities, the policy of neighbourhood tenure mix has resulted in a relatively low degree of segregation in spite of high concentrations...

  8. Perceptual-binding and persistent surface segregation.

    Science.gov (United States)

    Moradi, Farshad; Shimojo, Shinsuke

    2004-11-01

    Visual input is segregated in the brain into subsystems that process different attributes such as motion and color. At the same time, visual information is perceptually segregated into objects and surfaces. Here we demonstrate that perceptual segregation of visual entities based on a transparency cue precedes and affects perceptual binding of attributes. Adding an irrelevant transparency cue paradoxically improved the pairing of color and motion for rapidly alternating surfaces. Subsequent experiments show: (1) Attributes are registered over the temporal window defined by the perceptual persistence of segregation, resulting in asynchrony in binding, and (2) attention is necessary for correct registration of attributes in the presence of ambiguity.

  9. From particle segregation to the granular clock

    Energy Technology Data Exchange (ETDEWEB)

    Lambiotte, R. [Physique Statistique, Plasmas et Optique Non-lineaire, Universite Libre de Bruxelles, Campus Plaine, Boulevard du Triomphe, Code Postal 231, 1050 Brussels (Belgium)]. E-mail: rlambiot@ulb.ac.be; Salazar, J.M. [Universite De Bougogne-LRRS UMR-5613 CNRS, Faculte des Sciences Mirande, 9 Av. Alain Savary, 21078 Dijon Cedex (France)]. E-mail: jmarcos@u-bourgogne.fr; Brenig, L. [Physique Statistique, Plasmas et Optique Non-lineaire, Universite Libre de Bruxelles, Campus Plaine, Boulevard du Triomphe, Code Postal 231, 1050 Brussels (Belgium)]. E-mail: lbrenig@ulb.ac.be

    2005-08-01

    Recently several authors studied the segregation of particles for a system composed of mono-dispersed inelastic spheres contained in a box divided by a wall in the middle. The system exhibited a symmetry breaking leading to an overpopulation of particles in one side of the box. Here we study the segregation of a mixture of particles composed of inelastic hard spheres and fluidized by a vibrating wall. Our numerical simulations show a rich phenomenology: horizontal segregation and periodic behavior. We also propose an empirical system of ODEs representing the proportion of each type of particles and the segregation flux of particles. These equations reproduce the major features observed by the simulations.

  10. Declining Segregation of Same-Sex Partners: Evidence from Census 2000 and 2010.

    Science.gov (United States)

    Spring, Amy L

    2013-10-01

    Despite recent media and scholarly attention describing the "disappearance" of traditionally gay neighborhoods, urban scholars have yet to quantify the segregation of same-sex partners and determine whether declining segregation from different-sex partners is a wide-spread trend. Focusing on the 100 most populous places in the United States, I use data from the 2000 and 2010 Decennial Census to examine the segregation of same-sex partners over time and its place-level correlates. I estimate linear regression models to examine the role of four place characteristics in particular: average levels of education, aggregate trends in the family life cycle of same-sex partners, violence and social hostility motivated by sexual orientation bias, and representation of same-sex partners in the overall population. On average, same-sex partners were less segregated from different-sex partners in 2010 than in 2000, and the vast majority of same-sex partners lived in environments of declining segregation. Segregation was lower and declined more rapidly in places that had a greater percentage of graduate degree holders. In addition, segregation of female partners was lower in places that had a greater share of female partner households with children. These findings suggest that sexual orientation should be considered alongside economic status, race, and ethnicity as an important factor that contributes to neighborhood differentiation and urban spatial inequality.

  11. Assessment of equatorial F2-region peak parameters predictability using the IRI model

    Science.gov (United States)

    Oyekola, Oyedemi S.

    2012-07-01

    Overall behaviour of the F2-layer is believed to be described by the F2-layer peak parameters, which depend on various geophysical parameters including local time, season, solar and geomagnetic activity conditions. A better understanding of the variability and modeling of ionospheric peak characteristics is crucial for the development of ionospheric prediction capabilities, improvements in existing ionospheric models, and for radio propagation studies. The International Reference Ionosphere (IRI) model is used to assess the predictability of F2-region parameters and to validate F2-peak parameters simulation near the dip equator. We examine the main morphological patterns and climatological behaviour of equatorial F2 region over African sector using hourly observational values of F2 peak height of maximum electron density (hmF2), F2 layer peak electron density (NmF2), and propagation factor (M3000F2) hitherto made by the Ibadan ionosonde at 7.4oN, 3.9oE, dip latitude 2.3oS, in Nigeria; between January to December 1958, during a period of high solar activity (yearly averaged R12=190 units) and magnetically quiet conditions (Kp is less or equal to 3). The results of comparisons illustrate that good advancement has been made but reveal some important discrepancies. The trends in the experimental data are found to be in excellent agreement with the trends in the simulation results for maximum electron density and propagation factor, but fair-to-good for F2 layer peak altitude. The model is unable to capture the sharp postsunset and predawn enhancements in hmF2 and M3000F2, respectively. The model results have errors ranging from approximately 8-15 percent, 9-17 percent, and 3-5 percent, respectively, for hmF2, NmF2, and M3000F2. On average, the percent absolute relative difference of the model from the experimental observations varies from nearly 0-20 percent, 0-30 percent, and 0-10 percent for hmF2, NmF2, and M3000F2, in that order. Our results are essentially

  12. Multiparent intercross populations in analysis of quantitative traits

    Indian Academy of Sciences (India)

    Sujay Rakshit; Arunita Rakshit; J. V. Patil

    2011-04-01

    Most traits of interest to medical, agricultural and animal scientists show continuous variation and complex mode of inheritance. DNA-based markers are being deployed to analyse such complex traits, that are known as quantitative trait loci (QTL). In conventional QTL analysis, F2, backcross populations, recombinant inbred lines, backcross inbred lines and double haploids from biparental crosses are commonly used. Introgression lines and near isogenic lines are also being used for QTL analysis. However, such populations have major limitations like predominantly relying on the recombination events taking place in the F1 generation and mapping of only the allelic pairs present in the two parents. The second generation mapping resources like association mapping, nested association mapping and multiparent intercross populations potentially address the major limitations of available mapping resources. The potential of multiparent intercross populations in gene mapping has been discussed here. In such populations both linkage and association analysis can be conductted without encountering the limitations of structured populations. In such populations, larger genetic variation in the germplasm is accessed and various allelic and cytoplasmic interactions are assessed. For all practical purposes, across crop species, use of eight founders and a fixed population of 1000 individuals are most appropriate. Limitations with multiparent intercross populations are that they require longer time and more resource to be generated and they are likely to show extensive segregation for developmental traits, limiting their use in the analysis of complex traits. However, multiparent intercross population resources are likely to bring a paradigm shift towards QTL analysis in plant species.

  13. Z-scan measurement of the nonlinear refractive index of Nd(3+), Y(3+)-codoped CaF(2) and SrF(2) crystals.

    Science.gov (United States)

    Guo, Yue; Lu, Shunbin; Su, Liangbi; Zhao, Chujun; Zhang, Han; Wen, Shuangchun

    2015-02-01

    By performing the Z-scan measurements at 800 nm using a femtosecond pulsed laser, we are able to characterize the nonlinear refractive indices of Nd, Y codoped CaF(2) and SrF(2) crystals. Based on our measured results, we conclude that the doped fluoride crystal possesses a small nonlinear refractive index and the doping of Nd(3+) and Y(3+) ions in CaF(2) can change its third-order nonlinear index, but the contribution is minor. The doped fluoride crystal may have large potential to be developed as the next generation of gain material for a high-energy laser system.

  14. Improved quantification of 8-epi-prostaglandin F2 alpha and F2-isoprostanes by gas chromatography/triple-stage quadrupole mass spectrometry: partial cyclooxygenase-dependent formation of 8-epi-prostaglandin F2 alpha in humans.

    Science.gov (United States)

    Schweer, H; Watzer, B; Seyberth, H W; Nüsing, R M

    1997-12-01

    F2-isoprostanes are considered to be novel markers of lipid peroxidation. To study the in vivo formation of F2-isoprostanes, an improved method was developed for isotope dilution assays involving gas chromatography/triple-stage quadrupole mass spectrometry (GC/MS/MS) including thin-layer chromatography (TLC) (sum of all F2-isoprostanes) and high-performance liquid chromatographic (HPLC) purification (prostaglandin F2 alpha (PGF2 alpha) and 8-epi-PGF2 alpha). Following the addition of isotopically labeled prostaglandins to urine, the sample was acidified and applied to a C18 cartridge. After elution, prostaglandins were derivatized to pentafluorobenzyl esters and subjected to TLC. A broad zone was scratched off, isoprostanes were eluted and after formation of their trimethylsilyl ether derivatives the sum of F2-isoprostanes was determined by GC/MS/MS. For the determination of PGE2 alpha and 8-epi-PGF2 alpha prior to trimethylsilylation an additional HPLC step was performed and the fractions containing PGF2 alpha and 8-epi-PGF2 alpha were analyzed by GC/MS/MS. Using this technique, 8-epi-PGF2 alpha concentrations in urine samples as low as 5 pg ml-1 could be determined with high accuracy. The excretion rates of isoprostanes were studied in comparison with the classical prostaglandins in three different groups: healthy adults, healthy children and children with hyper-PGE syndrome (HPS), a pathological situation associated with a stimulated PGE2 synthesis. F2-isoprostanes represented the main arachidonic acid metabolites in these groups and 8-epi-PGF2 alpha excretion was comparable in its amount to the classical prostanoids. To delineate the cyclooxygenase-catalyzed contribution, the influence of indomethacin, an inhibitor of cyclooxygenases, on F2-isoprostane formation in healthy adults and in HPS children was analyzed. Significantly decreased excretion rates were observed 2 days after indomethacin administration for all prostanoids, including F2-isoprostanes and 8

  15. Segregation as Splitting, Segregation as Joining: Schools, Housing, and the Many Modes of Jim Crow

    Science.gov (United States)

    Highsmith, Andrew R.; Erickson, Ansley T.

    2015-01-01

    Popular understandings of segregation often emphasize the Jim Crow South before the 1954 "Brown" decision and, in many instances, explain continued segregation in schooling as the result of segregated housing patterns. The case of Flint, Michigan, complicates these views, at once illustrating the depth of governmental commitment to…

  16. Transgenerational effects of obesity and malnourishment on diabetes risk in F2 generation.

    Science.gov (United States)

    Hanafi, Mervat Y; Saleh, Moustafa M; Saad, Mohamed I; Abdelkhalek, Taha M; Kamel, Maher A

    2016-01-01

    Transgenerational inheritance of various diseases and phenotypes has been demonstrated in diverse species and involves various epigenetic markers. Obesity and malnourishment are nutritional stresses that have effects on offspring through increasing their risk of diabetes and/or obesity. Obesity and malnourishment both affect glucose metabolism and alter oxidative stress parameters in key organs. We induced obesity and malnutrition in F0 female rats by the use of obesogenic diet and protein-deficient diet, respectively. F0 obese and malnourished females were mated with control males and their offspring (F1 generation) were maintained on control diets. The male and female F1 offspring were mated with controls and the resultant offspring (F2 generation) were maintained on control diet. Glucose-sensing markers, glucose metabolism, indicators of insulin resistance and oxidative stress parameters were assessed during fetal development and till the adulthood of the offspring. Glucose-sensing genes were significantly over-expressed in distinct fetal tissues of F2 offspring of malnourished F1 females (F2-MF1F), specifically in fetal pancreas, liver, and adipose tissue. Nuclear and mitochondrial 8-oxo-dG DNA content was significantly elevated in F2-MF1F fetal pancreas. Maternal FBG was significantly elevated in F2-MF1F and F2 offspring of obese F1 females (F2-OF1F) during pregnancy. Males and females offspring of F2-OF1 exhibited significantly elevated FBG and impaired OGTT. Offspring of F2-MF1F showed similar results, while that of F2-MF1M did not significantly deviate from controls. F2-OF1F and F2-MF1F offspring exhibited significant deviation in insulin levels and HOMA-IR levels from controls. Malnourishment has a stronger transgenerational effect through maternal line compared to obesity and malnourishment through paternal line in increasing risk of diabetes in F2 generation.

  17. Revisiting the impact of occupational segregation on the gender earnings gap in Malaysia

    OpenAIRE

    Goy, Siew Ching; Johnes, Geraint

    2012-01-01

    More women participate in the labour force nowadays than in the past. However, they do not join the workforce as equal members. Segregation in occupational distribution and pay differentials between men and women remain pervasive. This article uses data from the Malaysian Population and Family Survey 2004 to shed light on the inequality in earnings based on the framework developed by Brown et al. (1980). The empirical results suggest that segregation per se works to the advantage of women. A ...

  18. Complex Refractive Index Measurements for BaF2 and CaF2 via Single-Angle Infrared Reflectance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kelly-Gorham, Molly Rose K.; De Vetter, Brent M.; Brauer, Carolyn S.; Cannon, Bret D.; Burton, Sarah D.; Bliss, Mary; Johnson, Timothy J.; Myers, Tanya L.

    2017-10-01

    We have re-investigated the optical constants n and k for the homologous series of inorganic salts barium fluoride (BaF2) and calcium fluoride (CaF2) using a single-angle near-normal incidence reflectance device in combination with a calibrated Fourier transform infrared (FTIR) spectrometer. Our results are in good qualitative agreement with most previous works. However, certain features of the previously published data near the reststrahlen band exhibit distinct differences in spectral characteristics. Notably, our measurements of BaF2 do not include a spectral feature in the ~250 cm-1 reststrahlen band that was previously published. Additionally, CaF2 exhibits a distinct wavelength shift relative to the model derived from previously published data. We confirmed our results with recently published works that use significantly more modern instrumentation and data reduction techniques

  19. Compact setup for the production of $^{87}$Rb $|F = 2, m_F = +2\\rangle$ Bose-Einstein condensates in a hybrid trap

    CERN Document Server

    Nolli, Raffaele; Marmugi, Luca; Wickenbrock, Arne; Renzoni, Ferruccio

    2016-01-01

    We present a compact experimental apparatus for Bose-Einstein condensation of $^{87}$Rb in the $|F = 2, m_F = +2\\rangle$ state. A pre-cooled atomic beam of $^{87}$Rb is obtained by using an unbalanced magneto-optical trap, allowing controlled transfer of trapped atoms from the first vacuum chamber to the science chamber. Here, atoms are transferred to a hybrid trap, as produced by overlapping a magnetic quadrupole trap with a far-detuned optical trap with crossed beam configuration, where forced radiofrequency evaporation is realized. The final evaporation leading to Bose-Einstein condensation is then performed by exponentially lowering the optical trap depth. Control and stabilization systems of the optical trap beams are discussed in detail. The setup reliably produces a pure condensate in the $|F = 2, m_F = +2\\rangle$ state in 50 s, which include 33 s loading of the science magneto-optical trap and 17 s forced evaporation.

  20. Computation of the chiral condensate using N{sub f}=2 and N{sub f}=2+1+1 dynamical flavors of twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Cichy, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Poznan Univ. (Poland). Faculty of Physics; Garcia-Ramos, E. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Humboldt-Universitaet, Berlin (Germany); Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Shindler, A. [Forschungszentrum Juelich (Germany). IAS; Forschungszentrum Juelich (Germany). IKP; Forschungszentrum Juelich (Germany). JCHP; Collaboration: European Twisted Mass Collaboration

    2013-12-15

    We apply the spectral projector method, recently introduced by Giusti and Luescher, to compute the chiral condensate using N{sub f}=2 and N{sub f}=2+1+1 dynamical flavors of maximally twisted mass fermions. We present our results for several quark masses at three different lattice spacings which allows us to perform the chiral and continuum extrapolations. In addition we report our analysis on the O(a) improvement of the chiral condensate for twisted mass fermions. We also study the effect of the dynamical strange and charm quarks by comparing our results for N{sub f}=2 and N{sub f}=2+1+1 dynamical flavors.

  1. Ising, Schelling and Self-Organising Segregation

    CERN Document Server

    Stauffer, D

    2007-01-01

    The similarities between phase separation in physics and residential segregation by preference in the Schelling model of 1971 are reviewed. Also, new computer simulations of asymmetric interactions different from the usual Ising model are presented, showing spontaneous magnetisation (= self-organising segregation) and in one case a sharp phase transition.

  2. Ising, Schelling and self-organising segregation

    Science.gov (United States)

    Stauffer, D.; Solomon, S.

    2007-06-01

    The similarities between phase separation in physics and residential segregation by preference in the Schelling model of 1971 are reviewed. Also, new computer simulations of asymmetric interactions different from the usual Ising model are presented, showing spontaneous magnetisation (=self-organising segregation) and in one case a sharp phase transition.

  3. Progressive segregation of the Escherichia coli chromosome

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.

    2006-01-01

    We have followed the fate of 14 different loci around the Escherichia coli chromosome in living cells at slow growth rate using a highly efficient labelling system and automated measurements. Loci are segregated as they are replicated, but with a marked delay. Most markers segregate in a smooth...

  4. Losing Ground: School Segregation in Massachuestts

    Science.gov (United States)

    Ayscue, Jennifer B.; Greenberg, Alyssa

    2013-01-01

    Though once a leader in school integration, Massachusetts has regressed over the last two decades as its students of color have experienced intensifying school segregation. This report investigates trends in school segregation in Massachusetts by examining concentration, exposure, and evenness measures by both race and class. First, the report…

  5. Occupational Segregation by Sex: Trends and Prospects.

    Science.gov (United States)

    Blau, Francine D.; Hendricks, Wallace E.

    1979-01-01

    Investigates postwar trends in occupational segregation. Finds segregation increased slightly between 1950-60 as predominantly female clerical/professional jobs increased. Occupation mix changes (1960-70) were neutral in impact, but male inflow into female professions and female inflow into male sales/clerical jobs produced modest segregation…

  6. Dipole model analysis of F2cc¯${m{F}}_2^{{m{car c}}} $ derived from the new D* data in DIS at HERA

    Directory of Open Access Journals (Sweden)

    Luszczak Agnieszka

    2012-12-01

    Full Text Available I analyse the new D* deep inelastic scattering data from HERA with the help of dipole models. I calculate F2cc¯${m{F}}_2^{{m{car c}}} $ from the GBW [1] and BGK [2] saturation models. I compare results with the last values determined by H1 at low Q2. I find good agreement with the data.

  7. Low $Q^{2}$ low $\\times$ structure function analysis of CCFR data for $F_{2}$

    CERN Document Server

    Tamminga, B H; Alton, A; Arroyo, C G; Avvakumov, S; Barbaro, L; Barbaro, P D; Bazarko, A O; Bernstein, R H; Bodek, Arie; Bolton, T; Brau, J E; Buchholz, D A; Budd, H S; Bugel, L; Conrad, J; Drucker, R B; Formaggio, J A; Frey, R; Goldman, J; Goncharov, M; Harris, D A; Johnson, R A; Kim, J H; King, B J; Kinnel, T; Koutsoliotas, S; Lamm, M J; Marsh, W; Mason, D; McFarland, K S; McNulty, C; Mishra, S R; Naples, D; Nienaber, P; Romosan, A; Sakumoto, W K; Schellman, H; Sciulli, F J; Seligman, W G; Shaevitz, M H; Smith, W H; Spentzouris, P; Stern, E G; Vakili, M; Vaitaitis, A G; Yang, U K; Zeller, G P; Zimmerman, E D

    2000-01-01

    Analyses of structure functions (SFs) from neutrino and muon deep inelastic scattering data have shown discrepancies in F2 for x < 0.1. A new SF analysis of the CCFR collaboration data examining regions in x down to x=.0015 and 0.4 < Q^2 < 1.0 is presented. Comparison to corrected charged lepton scattering results for F2 from the NMC and E665 experiments are made. Differences between muon and neutrino scattering allow that the behavior of F2 from muon scattering could be different from F2 from neutrino scattering as Q^2 approaches zero. Comparisons between F2 muon and F2 neutrino are made in this limit.

  8. Microstructure and Raman spectra of Ag-MgF2 cermet films

    Institute of Scientific and Technical Information of China (English)

    Shouhua Shi(史守华); Zhuoliang Cao(曹卓良); Zhaoqi Sun(孙兆奇)

    2003-01-01

    Ag-MgF2 cermet films with different Ag fractions were prepared by vacuum evaporation. The microstruc-ture of the films was examined by Raman scattering technique. The surface-enhanced Raman spectrumfor MgF2 molecules in the cermet film strongly suggests the existence of Ag nanoparticles dispersed inMgF2 matrix. The intensities of the Raman spectra of Ag-MgF2 cermet films increase with Ag fraction.The enhancement of Raman scattering disappears when Ag content reaches wt.20%. The analyses withthe transmission electron microscopy showed that Ag-MgF2 cermet films are mainly composed of amor-phous MgF2 matrix with embedded faced-center-cubic Ag nanoparticles. It suggests that the percolationthreshold should be around wt.20% of Ag content.

  9. Chromosome replication and segregation in bacteria.

    Science.gov (United States)

    Reyes-Lamothe, Rodrigo; Nicolas, Emilien; Sherratt, David J

    2012-01-01

    In dividing cells, chromosome duplication once per generation must be coordinated with faithful segregation of newly replicated chromosomes and with cell growth and division. Many of the mechanistic details of bacterial replication elongation are well established. However, an understanding of the complexities of how replication initiation is controlled and coordinated with other cellular processes is emerging only slowly. In contrast to eukaryotes, in which replication and segregation are separate in time, the segregation of most newly replicated bacterial genetic loci occurs sequentially soon after replication. We compare the strategies used by chromosomes and plasmids to ensure their accurate duplication and segregation and discuss how these processes are coordinated spatially and temporally with growth and cell division. We also describe what is known about the three conserved families of ATP-binding proteins that contribute to chromosome segregation and discuss their inter-relationships in a range of disparate bacteria.

  10. The Spatial Context of Residential Segregation

    CERN Document Server

    Roberto, Elizabeth

    2015-01-01

    Scholars have engaged in a longstanding debate about how best to measure residential segregation, and scores of indexes have been developed in response. However, the methods commonly employed are aspatial -- they summarize the characteristics of segregation patterns, such as concentration or clustering, but ignore their spatial features, such as how neighborhoods are spatially arranged. As a consequence, many studies find the same level of segregation whether a city has a patchwork of racial and ethnic enclaves, or is divided into large areas with little or no diversity. New methods have been developed to capture the spatial proximity of neighborhoods and the geographic scale of clustering. However, they lack a realistic measure of distance and do not accurately represent how segregation varies within cities. In this paper, I introduce a new method for studying the spatial context of residential segregation. I measure the distance between locations along city roads rather than in a straight line. Road distanc...

  11. Ionospheric foF2 morphology and response of F2 layer height over Jicamarca during different solar epochs and comparison with IRI-2012 model

    Indian Academy of Sciences (India)

    B O Adebesin; B J Adekoya; S O Ikubanni; S J Adebiyi; O A Adebesin; B W Joshua; K O Olonade

    2014-06-01

    Diurnal, seasonal and annual foF2 variability and the response of the F2-layer height over Jicamarca (11.9°S, 76.8°W, 1°N dip) during periods of low (LSA), moderate (MSA) and high (HSA) solar activities was investigated. The relative standard deviation (R) was used for the analysis. The F2-layer critical frequency pre-noon peak increases by a factor of 2 more than the post-noon peak as the solar activity increases. The variability coefficient (R) is lowest during the day (7–16%) for the three solar epochs; increases during nighttime (20–26%, 14–26%, and 10–20%, respectively for the LSA, MSA and HAS years); and attained highest magnitude during sunrise (21–27%, 24–27%, and 19–30%, respectively in similar order). Two major peaks were observed in R – the pre-sunrise peak, which is higher, and the post-sunset peak. Generally, the variability increases as the solar activity decreases. Annually, R peaks within 23–24%, 19–24% and 15–24% for the LSA, MSA, and HSA periods, respectively. The ionospheric F2-layer height rises to the higher level with increasing solar activity. The foF2 comparison results revealed that Jicamarca is well represented on the IRI-2012 model, with an improvement on the URSI option. The importance of vertical plasma drift and photochemistry in the F2-layer was emphasized.

  12. Additive colouring of CaF2:Yb crystals: determination of Yb2+ concentration in CaF2:Yb crystals and ceramics

    Science.gov (United States)

    Shcheulin, A. S.; Angervaks, A. E.; Semenova, T. S.; Koryakina, L. F.; Petrova, M. A.; Fedorov, P. P.; Reiterov, V. M.; Garibin, E. A.; Ryskin, A. I.

    2013-06-01

    When growing CaF2 crystal doped with rare-earth ions, most of these ions are present in a trivalent state. However, due to contact with graphite crucible, a small proportion of a number of ions (Eu, Sm, Yb and Tm) are reduced to a bivalent state. A similar situation takes place during fabrication of CaF2 ceramics doped with rare-earth metals. This fact is of particular importance for laser CaF2:Yb crystals (ceramics), a promising material for short-pulse, high-power, high-energy diode-pumped solid state lasers since the presence of bivalent Yb ions can be a source of thermal losses. To date, there has been no technique to determine Yb2+ concentration in as-grown crystals. The proposed technique is based on a total reduction of Yb3+ ions via the heating of as-grown CaF2 crystals with known concentration of Yb in the reducing atmosphere of metal vapour and determining the cross section of absorption bands of Yb2+ ions. The knowledge of these parameters allows estimation of the Yb2+ content in CaF2:Yb crystals or ceramics by analysing their absorption spectra. Examples of using this technique are given. The technology of CdF2 crystals reduction (an "additive colouring") and features of colouring of crystals doped with rare-earth ions are considered.

  13. F2-Isoprostanes in HDL are bound to neutral lipids and phospholipids.

    Science.gov (United States)

    Proudfoot, Julie M; Barden, Anne E; Croft, Kevin D; Galano, Jean-Marie; Durand, Thierry; Bultel-Poncé, Valérie; Giera, Martin; Mori, Trevor A

    2016-12-01

    Low HDL cholesterol (HDL-C) is a risk factor for coronary artery disease (CAD). However, interventions that raise HDL-C have failed to reduce cardiovascular events. We previously reported that HDL is the main carrier of plasma F2-isoprostanes (F2-IsoPs) that are markers of oxidative stress formed upon oxidation of arachidonic acid. F2-IsoPs are predominantly associated with phospholipids. However, there is evidence that F2-IsoPs in the liver of rats treated with carbon tetrachloride associate with the neutral lipids. To date it is not known whether F2-IsoPs are found in the neutral lipids in HDL in humans. Possible candidate neutral lipids include cholesteryl esters, triglycerides, diglycerides, and monoglycerides. This study aimed to identify the lipid classes within native and oxidized HDL that contain F2-IsoPs. We showed that F2-IsoPs in HDL are bound to neutral lipids as well as phospholipids. HDL-3 contained the highest concentration of F2-IsoPs in all lipid classes before and after in vitro oxidation. Using targeted LC/MS and high resolution MS, we were unable to provide conclusive evidence for the presence of the synthesized standards 15(R)-15-F2t-isoP cholesterol and 1-ent-15(RS)-15-F2t-isoprostanoyl-sn-glycerol in the neutral lipids of HDL. Our findings show that oxidized lipids such as F2-IsoPs are found in the core and surface of HDL. However, the exact molecular species remain to be definitively characterized. Future studies are required to determine whether the presence of F2-IsoPs in neutral lipids alters HDL function.

  14. On the tensor rank of multiplication in any extension of $\\F_2$

    CERN Document Server

    Ballet, Stéphane

    2010-01-01

    In this paper, we obtain new bounds for the tensor rank of multiplication in any extension of $\\F_2$. In particular, it also enables us to obtain the best known asymptotic bound. In this aim, we use the generalized algorithm of type Chudnovsky with derivative evaluations on places of degree one, two and four applied on the descent over $\\F_2$ of a Garcia-Stichtenoth tower of algebraic function fields defined over $\\F_{2^4}$.

  15. Mechanoluminescence and thermoluminesence in γ-irradiated rare earth doped CaF2 crystals

    Science.gov (United States)

    Brahme, Nameeta; Bisen, D. P.; Kher, R. S.; Khokhar, M. S. K.

    2009-08-01

    Mechanoluminescence (ML) and Thermoluminescence (TL) in γ-irradiated Dy, Ce, Er and Gd doped CaF2 crystals were studied. The crystals of doped CaF2 were grown by the Bridgman technique. The cleaved crystals were annealed at 450 ∘C for about two hours and cooled very slowly and then irradiated for different time from 60Co source having an exposure rate of 2.8×103 Gy/hr. ML was excited by applying uniaxial pressure on to the samples. Both the ML and TL intensities of CaF2 crystals increase with doping of rare earth impurities. Both the ML and TL intensity of γ-irradiated Dy, Ce, Er and Gd doped CaF2 crystals initially increase with increasing concentration of dopants obtaining an optimum value at 0.1 mole% level then further decreases with increasing dopant concentration. ML and TL intensity of γ-irradiated Dy, Ce, Er and Gd doped CaF2 crystals initially increases with the irradiation dose and then saturates at higher values of γ-doses. The order of ML and TL intensity for dopants were found similar and their order for decreasing intensity is CaF2:Dy>CaF2:Ce>CaF2:Er>CaF2:Gd. The ML spectra are almost similar to the TL spectra, this suggest that the centres emitting TL and ML may be the same although different processes cause their excitations.

  16. Spectroscopic, luminescent and laser properties of nanostructured CaF2:Tm materials

    Science.gov (United States)

    Lyapin, A. A.; Fedorov, P. P.; Garibin, E. A.; Malov, A. V.; Osiko, V. V.; Ryabochkina, P. A.; Ushakov, S. N.

    2013-08-01

    The laser quality transparent СаF2:Tm fluoride ceramics has been prepared by hot forming. Comparative study of absorption and emission spectra of СаF2:Tm (4 mol.% TmF3) ceramic and single crystal samples demonstrated that these materials possess almost identical spectroscopic properties. Laser oscillations of СаF2:Tm ceramics were obtained at 1898 nm under diode pumping, with the slope efficiency of 5.5%. Also, the continuous-wave (CW) laser have been obtained for СаF2:Tm single crystal at 1890 nm pumped by a diode laser was demonstrated.

  17. Quantitative trait loci mapping for flowering time in a switchgrass pseudo-F2 population

    Science.gov (United States)

    Flowering is an important developmental event in switchgrass (Panicum virgatum) because the onset of flowering causes the cessation of vegetative growth and biomass accumulation. The objective of this study was to generate a linkage map using single nucleotide polymorphism (SNP) markers to identify ...

  18. QTL analysis for early yield in a pseudo F2 population of cassava

    African Journals Online (AJOL)

    SERVER

    2008-01-18

    Jan 18, 2008 ... reconsideration of breeding strategies for improvement of this complex trait. Key words: ... markers can also facilitate marker- assisted selection. (MAS) in a modest ...... (1996). QTL analysis of pest resistance in the wild tomato.

  19. NOTE - Phenotypic correlations between combining abilities of F 2 cowpea populations

    Directory of Open Access Journals (Sweden)

    Carolline de Jesús Pires

    2012-09-01

    Full Text Available Cowpea is a crop that has become socio-economically relevant, mainly in developing countries. Correlation studies are important to determine the association between quantitative traits and yield to guide the selection, i.e., choose direct or indirect selection. The objective was to estimate the correlations between six agronomic traits in cowpea as well as the correlations between the estimates of combining abilities of parents. Genotypes with high pod weight and pod length, 100-grain weight, and number of beans per pod should be used to improve grain yield in cowpea. The breeder should preferably insert plants into his group of crosses that have a high combining ability for pod length, number of grains per pod and yield per plot.

  20. Municipal Solid Waste Management: Household Waste Segregation in Kuching South City, Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    Tunmise A. Otitoju

    2014-06-01

    Full Text Available Malaysia is faced with daunting challenges relating to household waste segregation. Due to an increase in population, economic growth, enforcement, infrastructure, public attitude, awareness and participation among others, source segregation is considered a crucial issue in Malaysia, particularly in urban settings. This paper presents the key findings of the quantitative (questionnaire survey administered among 235 households in Kuching South City and qualitative (interview survey with the Natural Resource & Environmental Board (NREB and Kuching South City Council. This survey attempts to identify the limiting and motivating factors on the part of households to waste segregation. The result shows that age, sex, race and education is insignificant towards waste segregation. The result also shows a significant difference between waste segregators and non-waste separators on their level of perception towards implementation of laws for source segregation. Result also shows that the ease of access to facilities and the methods of collection are the major limiting factors preventing households from waste segregation in Kuching South City.

  1. Mass Segregation in the Galactic Centre

    CERN Document Server

    Hopman, Clovis

    2010-01-01

    Two-body energy exchange between stars orbiting massive black holes (MBHs) leads to the formation of a power-law density distribution n(r)~r^(-a) that diverges towards the MBH. For a single mass population, a=7/4 and the flow of stars is much less than N(segregation with the use of Fokker-Planck calculations, and show that steady state is reached in 0.2-0.3 t_r. Since the relaxation time in the Galactic centre (GC) is t_r ~2-3 * 10^(10) yr, a cusp should form in less than a Hubble time. The absence of a visible cusp of old stars in the GC poses a challenge to these models, ...

  2. Itokawa: a case for ballistic segregation

    Science.gov (United States)

    Shinbrot, Troy; Sabawula, Tapan; Siu, Theo; Vivar Lazo, Miguel; Chakraborty, Pinaki

    Recent photographs of the asteroid Itokawa have revealed strong separation between regions populated almost entirely by small pebbles and other regions consisting only of larger boulders. This size separation has been attributed to the Brazil Nut Effect (BNE), however we point out here that the BNE depends on conditions such as isotropic gravity, parallel sidewalls and periodic vertical shaking that are wholly absent on asteroids. On the other hand, surface areas of boulders and pebbles appear to be comparable on Itokawa, and in this situation it follows that the asteroid must have suffered many orders of magnitude more collisions with pebbles than with boulders. We observe that a pebble will tend to bounce off of a boulder but will sink into a sea of similar pebbles, and so we predict that seas of pebbles must grow on such asteroids. We carry out experiments and simulations to evaluate this and related predictions, and we demonstrate that this new mechanism of segregation based on simple counting of grains can produce the strong separation of sizes reported. Support provided by NSF Grant 1404792.

  3. Modeling density segregation in granular flow

    Science.gov (United States)

    Xiao, Hongyi; Lueptow, Richard; Umbanhowar, Paul

    2015-11-01

    A recently developed continuum-based model accurately predicts segregation in flows of granular mixtures varying in particle size by considering the interplay of advection, diffusion and segregation. In this research, we extend the domain of the model to include density driven segregation. Discrete Element Method (DEM) simulations of density bidisperse flows of mono-sized particles in a quasi-2D bounded heap were performed to determine the dependence of the density driven segregation velocity on local shear rate, particle concentration, and a segregation length which scales with the particle size and the logarithm of the density ratio. With these inputs, the model yields theoretical predictions of density segregation patterns that quantitatively match the DEM simulations over a range of density ratios (1.11-3.33) and flow rates (19.2-113.6 cm3/s). Matching experiments with various combinations of glass, steel and ceramic particles were also performed which reproduced the segregation patterns obtained in both the simulations and the theory.

  4. Mapping quantitative trait loci for binary trait in the F2:3 design

    Indian Academy of Sciences (India)

    Chengsong Zhu; Yuan-Ming Zhang; Zhigang Guo

    2008-12-01

    In the analysis of inheritance of quantitative traits with low heritability, an F2:3 design that genotypes plants in F2 and phenotypes plants in F2:3 progeny is often used in plant genetics. Although statistical approaches for mapping quantitative trait loci (QTL) in the F2:3 design have been well developed, those for binary traits of biological interest and economic importance are seldom addressed. In this study, an attempt was made to map binary trait loci (BTL) in the F2:3 design. The fundamental idea was: the F2 plants were genotyped, all phenotypic values of each F2:3 progeny were measured for binary trait, and these binary trait values and the marker genotype informations were used to detect BTL under the penetrance and liability models. The proposed method was verified by a series of Monte–Carlo simulation experiments. These results showed that maximum likelihood approaches under the penetrance and liability models provide accurate estimates for the effects and the locations of BTL with high statistical power, even under of low heritability. Moreover, the penetrance model is as efficient as the liability model, and the F2:3 design is more efficient than classical F2 design, even though only a single progeny is collected from each F2:3 family. With the maximum likelihood approaches under the penetrance and the liability models developed in this study, we can map binary traits as we can do for quantitative trait in the F2:3 design.

  5. [Segregation of pigment cell anomalies in Munich miniature swine (MMS) Troll crossed with German Landrace].

    Science.gov (United States)

    Müller, S; Wanke, R; Distl, O

    1995-10-01

    In order to study the inheritance of melanocytic lesions in the Munich Miniature Swine (MMS) Troll, we established the F1-, F2- and R1-generations, starting with one melanoma-bearing MMS-Troll boar and four German Landrace sows as founder animals. A total of 168 animals were born, 24 in the F1-, 111 in the F2-, 19 in the B1DL-, and 14 in the B1Troll-generation. Benign lesions with lentigoid melanocytic hyperplasia or nests of hyperplastic melanocytes like in human junctional nevus were seen in 10 (41.7%) F1-, 17 (15.3%) F2-, 2 (10.5%) B1DL-, and 6 B1Troll-animals. Malignant melanomas occurred only in the F2-(4 animals; 3.6%) and in the B1Troll-(1 animal; 7.1%) generation. The observed segreation suggests different modes of inheritance for nevi and melanomas. The segregation of nevi can be explained by a major gene model with additional modification by a polygenic component. For melanoma, a major gene model does not fit the data sufficiently. Therefore, a two-or-three-locus model with doubled or tripled recessive affected animals has to be supposed for the inheritance of melanoma. Influence of SLA-haplotypes could not be observed.

  6. Genetic control and transgressive segregation of zinc, iron, potassium, phosphorus, calcium, and sodium accumulation in cowpea (Vigna unguiculata) seeds.

    Science.gov (United States)

    Fernandes Santos, C A; Boiteux, L S

    2015-01-16

    Cowpea crop, through combining a range of essential minerals with high quality proteins, plays an important role in providing nutritional security to human population living in semi-arid regions. Studies on genetics of biofortification with essential minerals are still quite scarce, and the major objective of the present study was to provide genetic information on development of cowpea cultivars with high seed mineral contents. Genetic parameters heritability and minimum number of genes were estimated for seed accumulation of zinc (Zn), iron (Fe), calcium (Ca), phosphorus (P), potassium (K), and sodium (Na). Generation mean and variance analyses were conducted using contrasting parental lines, F₁, F₂, and backcross populations derived from IT97K-1042-3 x BRS Tapaihum and IT97K-1042-3 x Canapu crosses. High narrow-sense heritability (h²) values were found for accumulation of Fe (65-86%), P (74-77%), and K (77-88%), whereas moderate h(2) values were observed for accumulation of Ca (41-56%), Zn (51-83%), and Na (50-55%) in seeds. Significant additive genetic effects as well as parental mean effects were detected in both crosses for all minerals, whereas epistasis was important genetic component in Zn content. The minimum number of genes controlling the accumulation of minerals ranged from two (K) to 11 (P). Transgressive segregation was observed in F2 populations of both crosses for all minerals analyzed. The results suggest that, although under either oligogenic or polygenic control, the seed content of these six minerals in cowpea can be improved via standard breeding methods largely used for self-pollinated crops.

  7. Veil: A Wall of Segregation

    Directory of Open Access Journals (Sweden)

    Tayebeh Nowrouzi

    2015-08-01

    Full Text Available Moving behind the confines of the race has been the continuous efforts of African-Americans so as to reveal and confirm their true humanity and abilities to white race as well as their own race. African-Americans, Dubois posited, are shut out of the white America, inhabiting behind a vast veil which creates a deep division between the races. Veil is made of the fabric of racism interwoven thread by thread and imposed by white world. It is thrown discourteously and forcibly to the African-Americans whom their distorted images are imposed on them and their true humanity and identity are hidden behind the veil. This study overtakes to present how Loraine Hansberry, in her first and the most outstanding drama, A Raisin in the Sun examines the world within the veil. She demonstrated that Duboisian metaphoric veil is operating in the racist American society so that not only African-Americans are segregated physically and psychologically from the rest of the world but also are inflicted with obscurity of vision that are neither able to see themselves clearly nor be seen truly. On the other hand, it presents how the veil provides blacks with the second sight to observe and comprehend the racist nature of whites which is hidden and incomprehensible for them.

  8. Genes that bias Mendelian segregation.

    Directory of Open Access Journals (Sweden)

    Pierre Grognet

    Full Text Available Mendel laws of inheritance can be cheated by Meiotic Drive Elements (MDs, complex nuclear genetic loci found in various eukaryotic genomes and distorting segregation in their favor. Here, we identify and characterize in the model fungus Podospora anserina Spok1 and Spok2, two MDs known as Spore Killers. We show that they are related genes with both spore-killing distorter and spore-protecting responder activities carried out by the same allele. These alleles act as autonomous elements, exert their effects independently of their location in the genome and can act as MDs in other fungi. Additionally, Spok1 acts as a resistance factor to Spok2 killing. Genetical data and cytological analysis of Spok1 and Spok2 localization during the killing process suggest a complex mode of action for Spok proteins. Spok1 and Spok2 belong to a multigene family prevalent in the genomes of many ascomycetes. As they have no obvious cellular role, Spok1 and Spok2 Spore Killer genes represent a novel kind of selfish genetic elements prevalent in fungal genome that proliferate through meiotic distortion.

  9. Genes that bias Mendelian segregation.

    Science.gov (United States)

    Grognet, Pierre; Lalucque, Hervé; Malagnac, Fabienne; Silar, Philippe

    2014-01-01

    Mendel laws of inheritance can be cheated by Meiotic Drive Elements (MDs), complex nuclear genetic loci found in various eukaryotic genomes and distorting segregation in their favor. Here, we identify and characterize in the model fungus Podospora anserina Spok1 and Spok2, two MDs known as Spore Killers. We show that they are related genes with both spore-killing distorter and spore-protecting responder activities carried out by the same allele. These alleles act as autonomous elements, exert their effects independently of their location in the genome and can act as MDs in other fungi. Additionally, Spok1 acts as a resistance factor to Spok2 killing. Genetical data and cytological analysis of Spok1 and Spok2 localization during the killing process suggest a complex mode of action for Spok proteins. Spok1 and Spok2 belong to a multigene family prevalent in the genomes of many ascomycetes. As they have no obvious cellular role, Spok1 and Spok2 Spore Killer genes represent a novel kind of selfish genetic elements prevalent in fungal genome that proliferate through meiotic distortion.

  10. Residential Segregation,Spatial Mismatch and Economic Growth across US Metropolitan Area

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Dr Harrison [University of North Carolina, Charlotte; Li, Huiping [ORNL

    2013-01-01

    Numerous studies have demonstrated the detrimental influence of residential segregation on poor inner-city residents. This study examines the impact of residential segregation on the welfare of populations in US metropolitan areas using economic growth as the indicator. Panel data of US metropolitan areas spanning 25 years, 1980 2005, are used to analyze the effect of segregation on economic growth. The results show that both racial and skill segregation have a negative impact on short and long-term economic growth, which have increased over time. Further, the negative impact of the variables associated with spatial mismatch is also revealed. The results clearly point to the need for mobility policies that favor non-White households and comprehensive strategies that promote economic opportunities in low-resource communities in the US.

  11. A Social Network Analysis of Occupational Segregation

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian; van der Leij, Marco

    We develop a social network model of occupational segregation between different social groups, generated by the existence of positive inbreeding bias among individuals from the same group. If network referrals are important for job search, then expected homophily in the contact network structure...... induces different career choices for individuals from different social groups. This further translates into stable occupational segregation equilibria in the labor market. We derive the conditions for wage and unemployment inequality in the segregation equilibria and characterize first and second best...

  12. Segregation of Polymers in Confined Spaces

    CERN Document Server

    Liu, Ya

    2009-01-01

    We investigate the motion of two overlapping polymers with self-avoidance confined in a narrow 2d box. A statistical model is constructed using blob free-energy arguments. We find spontaneous segregation under the condition: $L > R_{//}$, and mixing under $L < R_{//}$, where L is the length of the box, and $R_{//}$ the polymer extension in an infinite slit. Segregation time scales are determined by solving a mean first-passage time problem, and by performing Monte Carlo simulations. Predictions of the two methods show good agreement. Our results may elucidate a driving force for chromosomes segregation in bacteria.

  13. Measurement of Inclusive $\\rho^{0}, f_{0}(980), f_{2}(1270), K^{*0}_{2}(1430)$ and $f'_{2}(1525)$ Production in $Z^0$ Decays

    CERN Document Server

    Abreu, P; Adye, T; Adzic, P; Ajinenko, I; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Damgaard, G; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerdyukov, L N; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Grimm, H J; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Masik, J; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Myagkov, A; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rakoczy, D; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnova, O G; Smith, G R; Sokolov, A; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Chikilev, O G; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Todorova, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Vollmer, C F; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

    1999-01-01

    DELPHI results are presented on the inclusive production of the neutral mesons$\\rho^0$, $f_0(980)$, $f_2(1270)$, K$^{*0}_2(1430)$ and $f^{'}_2(1525)$ in hadronic Z$^0$ decays. They are based on about 2 million multihadronic events collected in 1994 and 1995, using the particle identification capabilities of the DELPHI Ring Imaging Cherenkov detectors and measured ionization losses in the Time Projection Chamber. The total production rates per hadronic Z$^0$ decay have been determined to be: $1.19 \\pm 0.10$ for $\\rho^0$; $0.164 \\pm 0.021$ for $f_0(980)$;$0.214 \\pm 0.038$ for $f_2(1270)$; 0:073 \\pm 0:023 for $K^{*0}_2 (1430)$; and 0:012 \\pm 0:006 for $f_{2}$(1525). The total production rates for all mesons and differential cross-sections for the $\\rho^{0}$, $f_{0}$(980) and $f_{2}$(1270) are compared with the results of other LEP experiments and with models.

  14. X-ray Excitation Triggers Ytterbium Anomalous Emission in CaF2:Yb but Not in SrF2:Yb.

    Science.gov (United States)

    Hughes-Currie, Rosa B; Ivanovskikh, Konstantin V; Wells, Jon-Paul R; Reid, Michael F; Gordon, Robert A; Seijo, Luis; Barandiarán, Zoila

    2017-02-27

    Materials that luminesce after excitation with ionizing radiation are extensively applied in physics, medicine, security, and industry. Lanthanide dopants are known to trigger crystal scintillation through their fast d-f emissions; the same is true for other important applications as lasers or phosphors for lighting. However, this ability can be seriously compromised by unwanted anomalous emissions often found with the most common lanthanide activators. We report high-resolution X-ray-excited optical (IR to UV) luminescence spectra of CaF2:Yb and SrF2:Yb samples excited at 8949 eV and 80 K. Ionizing radiation excites the known anomalous emission of ytterbium in the CaF2 host but not in the SrF2 host. Wave function-based ab initio calculations of host-to-dopant electron transfer and Yb(2+)/Yb(3+) intervalence charge transfer explain the difference. The model also explains the lack of anomalous emission in Yb-doped SrF2 excited by VUV radiation.

  15. Phosphate Capacities of CaF2-MgO and CaF2-CaO-MgO Slags

    Science.gov (United States)

    Akbari, F.; Pickles, C. A.

    2015-02-01

    Previously published sulphide capacity data and thermodynamic arguments have been employed to calculate the phosphate capacities and the phosphorus partition ratios between a molten carbon saturated iron alloy and binary CaF2-MgO slags and also ternary CaF2 -CaO-MgO slags at 1450 °C. For the CaF2-MgO binary system, a linear relationship was found between the phosphate and the sulphide capacities as follows: log ? = 1.2 log Cs + 25.2. For the ternary CaF2-CaO-MgO system at 1450 °C, the logarithm of the calculated phosphate capacities ranged from 19.47 to 20.15. With the addition of CaO, the phosphate capacities initially increased, reached a maximum and then decreased slightly. The addition of MgO to the CaF2-CaO system resulted in a decrease in the phosphate capacity. The calculated phosphorus partition ratios increased slightly with increasing mole fraction of CaO in the ternary system.

  16. Implementing an analytical formula for calculating M(3000)F2 in the ionosonde operated in Havana

    CERN Document Server

    González, Arian Ojeda; Alazo, Katy; Calzadilla, Alexander

    2013-01-01

    Determining the factor M(3000)F2 is very important for ionograms analysis obtained of Ionosonde. M(3000)F2 is the result of the maximum usable frequency (MUF), for to 3000 km distance, divided by the critical frequency of the F2 layer (FoF2). Nowadays, the graphic method to determine the M(3000)F2 is used in Havana station in the ionograms analysis. The purpose of this work is to implement an analytic method that allows us the direct obtaining of M(3000)F2, so it could be programmed and incorporated as part of ionograms elaboration process in Havana station. When is used a PC, some points in the ionogram can be determined. This dataset (f; h') are used to calculate analytically the factor M(3000)F2 . Comparison between the analytic method implemented and the old graphic method are shown. The new method is more accurate and the errors are diminished in the factor M(3000)F2.

  17. Maps of Ionospheric F2-Layer Characteristics Derived from GPS Radio Occultation Observations

    Directory of Open Access Journals (Sweden)

    Lung-Chih Tsai

    2009-01-01

    Full Text Available The Global Positioning System (GPS radio occultation (RO technique has been used to receive multi-channel GPS carrier phase signals from low Earth or biting (LEO satellites and demon strate active limb sounding of the Earth¡¦s ionosphere. Apply ing Abel inversion through compen sated total electron content (TEC values, the GPS RO observations can obtainion o spheric electron density (ne profiles and then scale F2-layer characteristics including foF2 and hmF2, especially, hmF2 that can not be directly deduced from ionosonde observations. From the GPS/MET and FS3/COS MIC mis sions, we can col lect on average two hundred and eighteen hundred vertical neprofiles, respectively, within one day. The retrieved foF2 and hmF2 re sults have been used to produce numerical maps representing complex prop erties on a world-wide scale. This paperpresents aphysically appeal ing represen tation of foF2 and hmF2 medians based on GPS RO data. The derived numerical maps have also been examined by ground-based ionosonde data.

  18. On the oscillator strengths of MgO and F2

    NARCIS (Netherlands)

    Main, R.P.; Schadee, A.

    1969-01-01

    In a recent paper (R. P. Main, D. J. Carlson and R. A. DuPuis, JQSRT 7, 805 (1967)), measurements of oscillator strengths of electronic transitions in the MgO-, MgH-, and F2-molecules were reported. We point out that the results reported in that paper for F2 are almost certainly invalid, and that an

  19. Absence of systemic oxidative stress and increased CSF prostaglandin F2α in progressive MS

    DEFF Research Database (Denmark)

    Lam, Magda A; Maghzal, Ghassan J; Khademi, Mohsen

    2016-01-01

    OBJECTIVE: We aimed to investigate the role of oxidative stress in the progression of multiple sclerosis (MS). METHODS: We determined by liquid chromatography-tandem mass spectrometry nonenzymatic (F2-isoprostanes) and enzymatic oxidation products of arachidonic acid (prostaglandin F2α [PGF2α]) i...

  20. Pilot Milt Thompson and the M2-F2 Lifting Body

    Science.gov (United States)

    1966-01-01

    Jay L. King, Joseph D. Huxman and Orion D. Billeter assist NASA research pilot Milt Thompson (on the ladder) into the cockpit of the M2-F2 lifting body research aircraft at the NASA Flight Research Center (now the Dryden Flight Research Center). The M2-F2 is attached to a wing pylon under the wing of NASA's B-52 mothership.

  1. The new readout electronics for the BaF2-calorimeter TAPS

    NARCIS (Netherlands)

    Drexler, P; Thoring, U; Bonn, W; van der Duin, HAP; Holzmann, R; van der Kruk, G; Krusche, B; Lohner, H; Metag, [No Value; Nijboer, TW; Novotny, R; Potapov, A; Salz, C; Schadmand, S; Steinacher, M; Thiel, M; Vorenholt, H

    2003-01-01

    A highly compact and fast VME based readout board for BaF2 scintillation detectors has been designed, developed, and finally tested in an in-beam experiment. Adapted to the excellent properties of BaF2, the unit allows to digitize time, energy, and pulse-shape information of four detector channels i

  2. A Theoretical Study of Super-Excited States of F2

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Hua; HE Chun-long; HAO Yu-Song; MO Yu-Xiang; Li Jia-Ming

    2007-01-01

    In the framework of quantum defect theory, we study super-excited states of F2 molecules which can dissociate into F+(3P2,1,0) and F-(1So) ion-pair. Based on our calculation, we present a vibrational resolved assignment of the high precision photofragment yield spectra for F- from the F2 ion-pair production.

  3. Optical properties of Cr3+ in fluorite-structure hosts and in MgF*2

    Science.gov (United States)

    Payne, Stephen A.; Chase, L. L.; Krupke, William F.

    1987-03-01

    We have examined the optical properties of Cr3+ in MgF2 and in the fluorite-structure hosts: CdF2, CaF2, SrF2, and BaF2. The properties of Cr3+ in MgF2 are similar to those observed for other fluoride crystals that have octahedral substitutional metal sites. Interestingly, Cr3+ is also found to be sixfold coordinated in the fluorite hosts, despite the fact that the metal sites of these crystal lattices are eightfold coordinated. The smaller ionic radius of Cr3+ compared to, say, Ca2+, undoubtedly results in considerable relaxation at the metal site. However, the crystal field stabilization energy present in the 4A2(d3) ground state also provides for the energetic preference of sixfold vs eightfold coordination. The similarity of the observed absorption spectra of Cr3+ in MgF2 and in fluorite give evidence that the ground state is octahedrally coordinated in all of these hosts. The reduction of this electronic stabilization energy in the 4T2(d3) excited state is considered to produce a configurational shift relative to the ground state. This shift may be the reason why Cr3+ luminesces effectively in MgF2 whereas it is largely quenched in the fluorite-structure materials.

  4. The new readout electronics for the BaF2-calorimeter TAPS

    NARCIS (Netherlands)

    Drexler, P; Thoring, U; Bonn, W; van der Duin, HAP; Holzmann, R; van der Kruk, G; Krusche, B; Lohner, H; Metag, [No Value; Nijboer, TW; Novotny, R; Potapov, A; Salz, C; Schadmand, S; Steinacher, M; Thiel, M; Vorenholt, H

    A highly compact and fast VME based readout board for BaF2 scintillation detectors has been designed, developed, and finally tested in an in-beam experiment. Adapted to the excellent properties of BaF2, the unit allows to digitize time, energy, and pulse-shape information of four detector channels

  5. Determination of the ionospheric foF2 using a stand-alone GPS receiver

    Science.gov (United States)

    Wijaya, Dudy D.; Haralambous, Haris; Oikonomou, Christina; Kuntjoro, Wedyanto

    2017-09-01

    The critical frequency of ionospheric F2 layer (foF2) is a measure of the highest frequency of radio signal that may be reflected back by the F2 layer, and it is associated with ionospheric peak electron density in the F2 layer. Accurate long-term foF2 variations are usually derived from ionosonde observations. In this paper, we propose a new method to observe foF2 using a stand-alone global positioning system (GPS) receiver. The proposed method relies on the mathematical equation that relates foF2 to GPS observations. The equation is then implemented in the Kalman filter algorithm to estimate foF2 at every epoch of the observation (30-s rate). Unlike existing methods, the proposed method does not require any additional information from ionosonde observations and does not require any network of GPS receivers. It only requires as inputs the ionospheric scale height and the modeled plasmaspheric electron content, which practically can be derived from any existing ionospheric/plasmaspheric model. We applied the proposed method to estimate long-term variations of foF2 at three GPS stations located at the northern hemisphere (NICO, Cyprus), the southern hemisphere (STR1, Australia) and the south pole (SYOG, Antarctic). To assess the performance of the proposed method, we then compared the results against those derived by ionosonde observations and the International Reference Ionosphere (IRI) 2012 model. We found that, during the period of high solar activity (2011-2012), the values of absolute mean bias between foF2 derived by the proposed method and ionosonde observations are in the range of 0.2-0.5 MHz, while those during the period of low solar activity (2009-2010) are in the range of 0.05-0.15 MHz. Furthermore, the root-mean-square-error (RMSE) values during high and low solar activities are in the range of 0.8-0.9 MHz and of 0.6-0.7 MHz, respectively. We also noticed that the values of absolute mean bias and RMSE between foF2 derived by the proposed method and the

  6. X-ray excited luminescence of polystyrene composites loaded with SrF2 nanoparticles

    Science.gov (United States)

    Demkiv, T. M.; Halyatkin, O. O.; Vistovskyy, V. V.; Hevyk, V. B.; Yakibchuk, P. M.; Gektin, A. V.; Voloshinovskii, A. S.

    2017-03-01

    The polystyrene film nanocomposites of 0.3 mm thickness with embedded SrF2 nanoparticles up to 40 wt% have been synthesized. The luminescent and kinetic properties of the polystyrene composites with embedded SrF2 nanoparticles upon the pulse X-ray excitation have been investigated. The luminescence intensity of the pure polystyrene scintillator film significantly increases when it is loaded with the inorganic SrF2 nanoparticles. The film nanocomposites show fast (∼2.8 ns) and slow (∼700 ns) luminescence decay components typical for a luminescence of polystyrene activators (p-Terphenyl and POPOP) and SrF2 nanoparticles, respectively. It is revealed that the fast decay luminescence component of the polystyrene composites is caused by the excitation of polystyrene by the photoelectrons escaped from the nanoparticles due to photoeffect, and the slow component is caused by reabsorption of the self-trapped exciton luminescence of SrF2 nanoparticles by polystyrene.

  7. The effect of CaF2 on thermodynamics of CaO-CaF2-SiO2(-MgO) slags

    Science.gov (United States)

    Choi, Chul-Hwan; Jo, Sung-Koo; Kim, Seon-Hyo; Lee, Kwang-Ro; Kim, Jeong-Tae

    2004-02-01

    To address the role of CaF2 in the CaO-CaF2-SiO2(-MgO) slag system employed for the production of low-pressure rotor steels, the thermodynamic aspects of the slag were investigated by equilibrating it with liquid iron at 1873 K in CaO or MgO crucibles. Presaturation of slag with an oxide block piece of CaO or MgO in a Pt crucible and application of a carbon paste to the outside of an oxide crucible were designed to prevent crucible failure during the slag-metal experiments. The liquidus isotherm and phase boundary of the preceding slag system were investigated using the slag-metal equilibria. Also, the effect of CaF2 on the sulfide capacity and the activity coefficient of Fe t O were of particular interest in controlling the sulfur level and cleanliness of low-pressure rotor steels.

  8. Possible segregation caused by centrifugal titanium casting.

    Science.gov (United States)

    Watanabe, K; Okawa, S; Kanatani, M; Nakano, S; Miyakawa, O; Kobayashi, M

    1996-12-01

    The possibility of the segregation under solidification process using a centrifugal casting machine was investigated using an electron probe microanalyzer with elemental distribution map, line analysis and quantitative analysis. When a very small quantity of platinum was added to local molten titanium during the casting process, macroscopic segregation was observed under conditions of density difference of 0.1 g/cm3 at the most, confirming that the centrifugal force of the casting machine is extremely strong. When a Ti-6Al-4V alloy was cast, however, no macroscopic segregation was observed. The centrifugal force of the casting machine examined in the present study hardly results in the body-force segregation in this titanium alloy.

  9. Entropy as the driver of chromosome segregation

    OpenAIRE

    Jun, Suckjoon; Wright, Andrew

    2010-01-01

    We present a new physical biology approach to understanding the relationship between the organization and segregation of bacterial chromosomes. We posit that replicated Escherichia coli daughter strands will spontaneously demix as a result of entropic forces, despite their strong confinement within the cell; in other words, we propose that entropy can act as a primordial physical force which drives chromosome segregation under the right physical conditions. Furthermore, proteins implicated in...

  10. OCCUPATIONAL SEGREGATION BY GENDER - WHERE DOES ROMANIA STAND?

    Directory of Open Access Journals (Sweden)

    Manciu Venera

    2015-07-01

    Full Text Available The issue of occupational segregation is a topic discussed in the foreign economic literature, but on which documents written by Romanian authors are not so numerous. Still, during the last decades, this problem gained attention and began to preoccupy more individuals, especially on the basis of female emancipation process. In the past, various occupations were destined to be developed only by male employees. Women represent more than half of the overall population of the world. Even if prejudices on women are no longer as intense as they were in the past, and the access to education is widely open even in less-developed countries, consequently increasing the number of female workers, there are still several issues regarding occupational segregation and gender inequality that need to be solved. Today, many prejudices are lost, and female employees are more appreciated and manage to occupy traditional positions, as well as the ones that in the past were allocated only for the opposite gender. An assumption met in literature is that a rich country is able to confront more efficiently its problems and that the level of development should lower the gender gaps also. The purpose of this paper is to illustrate the situation of occupational segregation in Romania, through both theoretical and empirical methods. Still, the research is a qualitative one, considering that the available data is limited, at the present moment. The first part illustrates the concept of gender equality and occupational segregation, followed by an interpretation of the official data provided by the reports elaborated by the institutes in the field. The last part consist in a brief analysis of the relationship between the gender equality index and the economic growth, illustrated by the values of GDP.

  11. Transport analogy for segregation and granular rheology

    Science.gov (United States)

    Liu, Siying; McCarthy, Joseph J.

    2017-08-01

    Here, we show a direct connection between density-based segregation and granular rheology that can lead to insight into both problems. Our results exhibit a transition in the rate of segregation during simple shear that occurs at I ˜0.5 and mimics a coincident regime change in flow rheology. We propose scaling arguments that support a packing fraction criterion for this transition that can both explain our segregation results as well as unify existing literature studies of granular rheology. By recasting a segregation model in terms of rheological parameters, we establish an approach that not only collapses results for a wide range of conditions, but also yields a direct relationship between the coordination number z and the segregation velocity. Moreover, our approach predicts the precise location of the observed regime change or saturation. This suggests that it is possible to rationally design process operating conditions that lead to significantly lower segregation extents. These observations can have a profound impact on both the study of granular flow or mixing as well as industrial practice.

  12. Plasma 8-iso-Prostaglandin F2α concentrations and outcomes after acute intracerebral hemorrhage.

    Science.gov (United States)

    Du, Quan; Yu, Wen-Hua; Dong, Xiao-Qiao; Yang, Ding-Bo; Shen, Yong-Feng; Wang, Hao; Jiang, Li; Du, Yuan-Feng; Zhang, Zu-Yong; Zhu, Qiang; Che, Zhi-Hao; Liu, Qun-Jie

    2014-11-01

    Higher plasma 8-iso-Prostaglandin F2α concentrations have been associated with poor outcome of severe traumatic brain injury. We further investigated the relationships between plasma 8-iso-Prostaglandin F2α concentrations and clinical outcomes in patients with acute intracerebral hemorrhage. Plasma 8-iso-Prostaglandin F2α concentrations of 128 consecutive patients and 128 sex- and gender-matched healthy subjects were measured by enzyme-linked immunosorbent assay. We assessed their relationships with disease severity and clinical outcomes including 1-week mortality, 6-month mortality and unfavorable outcome (modified Rankin Scale score>2). Plasma 8-iso-Prostaglandin F2α concentrations were substantially higher in patients than in healthy controls. Plasma 8-iso-Prostaglandin F2α concentrations were positively associated with National Institutes of Health Stroke Scale (NIHSS) scores and hematoma volume using a multivariate linear regression. It emerged as an independent predictor for clinical outcomes of patients using a forward stepwise logistic regression. ROC curves identified the predictive values of plasma 8-iso-Prostaglandin F2α concentrations, and found its predictive value was similar to NIHSS scores and hematoma volumes. However, it just numerically added the predictive values of NIHSS score and hematoma volume. Increased plasma 8-iso-Prostaglandin F2α concentrations are associated with disease severity and clinical outcome after acute intracerebral hemorrhage. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Decomposition treatment of SO2F2 using packed bed DBD plasma followed by chemical absorption.

    Science.gov (United States)

    Nie, Yong; Zheng, Qifeng; Liang, Xiaojiang; Gu, Dayong; Lu, Meizhen; Min, Min; Ji, Jianbing

    2013-07-16

    The technology of packed bed dielectric barrier discharge (DBD) plasma followed by a chemical absorption has been developed and was found to be an efficient way for decomposition treatment of sulfuryl fluoride (SO2F2) in simulated residual fumigant. The effects of energy density, initial SO2F2 concentration, and residence time on the removal efficiency of SO2F2 for the DBD plasma treatment alone were investigated. It was found that the SO2F2 could be removed completely when initial volume concentration, energy density, and residence time were 0.5%, 33.9 kJ/L, and 5.1 s, respectively. The removal mechanism of SO2F2 in the packed bed DBD reactor was discussed. Based on the detailed analysis of SO2F2 molecular stability and its exhaust products in the DBD plasma reactor, it was concluded that the energetic electrons generated in the packed bed DBD reactor played a key role on the removal of SO2F2, and the major decomposition products of SO2F2 detected were SO2, SiF4, and S (Sulfur). Among these products, SiF4 was formed by the F atom reacted with the filler-quartz glass beads (SiO2) in the packed bed DBD reactor. Aqueous NaOH solution was used as the chemical absorbent for the gaseous products of SO2F2 after plasma pretreatment. It was found that the gaseous products in the plasma exhaust could be absorbed and fixed by the subsequent aqueous NaOH solution.

  14. Effect of 1918 PB1-F2 expression on influenza A virus infection kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Ruy [Los Alamos National Laboratory; Perelson, Alan S [Los Alamos National Laboratory; Smith, Amber M [UNIV OF UTAH; Adler, Frederick R [UNIV OF UTAH; Mcauley, Julie L [ST. JUDES CHILDREN RESEARCH; Mccullers, Jonathan A [ST. JUDES CHILDREN RESEARCH

    2009-01-01

    Relatively little is known about the viral factors contributing to the lethality of the 1918 pandemic, although its unparalleled virulence was likely due in part to the newly discovered PB1-F2 protein. This protein, while unnecessary for replication, increases apoptosis in monocytes, alters viral polymerase activity in vitro, and produces enhanced inflammation and increased secondary pneumonia in vivo. However, the effects the PB1-F2 protein have in vivo remain unclear. To address the mechanisms involved, we intranasally infected groups of mice with either influenza A virus PR8 or a genetically engineered virus that expresses the 1918 PB1-F2 protein on a PR8 background, PR8-PB1-F2(1918). Mice inoculated with PR8 had viral concentrations peaking at 72 hours, while those infected with PR8-PB1-F2(1918) reached peak concentrations earlier, 48 hours. Mice given PR8-PB1-F2(1918) also showed a faster decline in viral loads. We fit a mathematical model to these data to estimate parameter values and select the best model. This model supports a lower viral clearance rate and higher infected cell death rate with the PR8-PB1-F2(1918) virus, although the viral production rate may also be higher. We hypothesize that the higher PR8-PB1-F2(1918) viral titers early in an infection are due to both an increase in viral production with decreased viral clearance, and that the faster decline in the later stages of infection result from elevated cell death rates. We discuss the implications these mechanisms have during an infection with a virus expressing a virulent PBI-F2 on the possibility of a pandemic and on the importance of antiviral treatments.

  15. Nuclear medium effects in $F_{2A}^{EM}(x,Q^2)$ and $F_{2A}^{Weak}(x,Q^2)$ structure functions

    CERN Document Server

    Haider, H; Athar, M Sajjad; Singh, S K; Simo, I Ruiz

    2016-01-01

    Recent phenomenological analysis of experimental data on DIS processes induced by charged leptons and neutrinos/antineutrinos beams on nuclear targets by CTEQ collaboration has confirmed the observation of CCFR and NuTeV collaborations, that weak structure function $F_{2A}^{Weak} (x,Q^2)$ is different from electromagnetic structure function $F_{2A}^{EM} (x,Q^2)$ in a nucleus like iron, specially in the region of low $x$ and $Q^2$. In view of this observation we have made a study of nuclear medium effects on $F_{2A}^{Weak} (x,Q^2)$ and $F_{2A}^{EM} (x,Q^2)$ for a wide range of $x$ and $Q^2$ using a microscopic nuclear model. We have considered Fermi motion, binding energy, nucleon correlations, mesonic contributions from pion and rho mesons and shadowing effects to incorporate nuclear medium effects. The calculations are performed in a local density approximation using a relativistic nucleon spectral function which includes nucleon correlations. The numerical results in the case of iron nucleus are compared wi...

  16. Atmospheric chemistry of n-CxF2x+1CHO (x = 1, 2, 3, 4)

    DEFF Research Database (Denmark)

    Hurley, M. D.; Ball, J. C.; Wallington, T. J.;

    2006-01-01

    Smog chamber/FTIR techniques were used to study the atmospheric fate of n-C(x)F(2)(x)(+1)C(O) (x = 1, 2, 3, 4) radicals in 700 Torr O(2)/N(2) diluent at 298 +/- 3 K. A competition is observed between reaction with O(2) to form n-C(x)()F(2)(x)()(+1)C(O)O(2) radicals and decomposition to form n-C(x...... to the atmospheric chemistry of n-C(x)F(2)(x)(+1)C(O) radicals and their possible role in contributing to the formation of perfluorocarboxylic acids in the environment....

  17. Vibrational spectra of (BaF2)n (n=1-6) clusters

    Science.gov (United States)

    Pandey, Ratnesh K.; Waters, Kevin; Nigam, Sandeep; Pandey, Ravindra; Pandey, Avinash C.

    2016-05-01

    The vibrational properties of alkaline-earth metal fluoride clusters (BaF2)n (n=1-6) are investigated in the framework of density functional theory. The calculated Raman and Infrared (IR) spectra reveals shift in Raman and IR peak position towards lower frequency region with the increase in the cluster size. Further the calculated spectra have been compared with the experimental vibrational spectra of bulk BaF2 crystal. Even though the smaller size cluster lacks translational symmetry, the structural and vibrational characteristic of (BaF2)5-6 are nearer to bulk counterpart.

  18. Optical Properties of MgF2 / MgF2 / Glass and MgF2 / TiO2 / Glass

    Directory of Open Access Journals (Sweden)

    S. Ghahramani

    2014-01-01

    Full Text Available MgF2 thin films by thickness of 93 nm were deposited on MgF2 / glass and TiO2 / glass thin layers by resistance evaporation method under ultra-high vacuum (UHV conditions, rotating pre layer for sample one and normal deposition for second one. Optical properties were measured via spectrophotometer in spectral range of 300-1100 nm wave length. The optical constants such as, real part of refractive index (n, imaginary part of refractive index (k, real and imaginary parts of dielectric function ε1, ε2 respectively and absorption coefficient (, were obtained from Kramers-Kronig analysis of reflectivity curves. Band-gap energy was also estimated for these films.

  19. Genetic and comparative genomics mapping reveals that a powdery mildew resistance gene Ml3D232 originating from wild emmer co-segregates with an NBS-LRR analog in common wheat (Triticum aestivum L.).

    Science.gov (United States)

    Zhang, Hongtao; Guan, Haiying; Li, Jingting; Zhu, Jie; Xie, Chaojie; Zhou, Yilin; Duan, Xiayu; Yang, Tsomin; Sun, Qixin; Liu, Zhiyong

    2010-11-01

    Powdery mildew caused by Blumeria graminis f. sp. tritici is one of the most important wheat diseases worldwide and breeding for resistance using diversified disease resistance genes is the most promising approach to prevent outbreaks of powdery mildew. A powdery mildew resistance gene, originating from wild emmer wheat (Triticum turgidum var. dicoccoides) accessions collected from Israel, has been transferred into the hexaploid wheat line 3D232 through crossing and backcrossing. Inoculation results with 21 B. graminis f. sp. tritici races indicated that 3D232 is resistant to all of the powdery mildew isolates tested. Genetic analyses of 3D232 using an F(2) segregating population and F(3) families indicated that a single dominant gene, Ml3D232, confers resistance in the host seedling stage. By applying molecular markers and bulked segregant analysis (BSA), we have identified polymorphic simple sequence repeats (SSR), expressed sequence tags (EST) and derived sequence tagged site (STS) markers to determine that the Ml3D232 is located on chromosome 5BL bin 0.59-0.76. Comparative genetic analyses using mapped EST markers and genome sequences of rice and Brachypodium established co-linearity of the Ml3D232 genomic region with a 1.4 Mb genomic region on Brachypodium distachyon chromosome 4, and a 1.2 Mb contig located on the Oryza sativa chromosome 9. Our comparative approach enabled us to develop new EST-STS markers and to delimit the genomic region carrying Ml3D232 to a 0.8 cM segment that is collinear with a 558 kb region on B. distachyon. Eight EST markers, including an NBS-LRR analog, co-segregated with Ml3D232 to provide a target site for fine genetic mapping, chromosome landing and map-based cloning of the powdery mildew resistance gene. This newly developed common wheat germplasm provides broad-spectrum resistance to powdery mildew and a valuable resource for wheat breeding programs.

  20. Investigating mass segregation process in globular clusters with Blue Straggler Stars: the impact of dark remnants

    CERN Document Server

    Alessandrini, Emiliano; Ferraro, Francesco Rosario; Miocchi, Paolo; Vesperini, Enrico

    2016-01-01

    We present the results of a set of N-body simulations aimed at exploring how the process of mass segregation (as traced by the spatial distribution of blue straggler stars, BSSs) is affected by the presence of a population of heavy dark remnants (as neutron stars and black holes). To this end, clusters characterized by different initial concentrations and different fractions of dark remnants have been modeled. We find that an increasing fraction of stellar-mass black holes significantly delays the mass segregation of BSSs and the visible stellar component. In order to trace the evolution of BSS segregation, we introduce a new parameter ($A^+$) that can be easily measured when the cumulative radial distribution of these stars and a reference population are available. Our simulations show that $A^+$ might also be used as an approximate indicator of the time remaining to the core collapse of the visible component.

  1. A variable transverse stiffness sandwich structure using fluidic flexible matrix composites (F2MC)

    Science.gov (United States)

    Li, Suyi; Lotfi, Amir; Shan, Ying; Wang, K. W.; Rahn, Christopher D.; Bakis, Charles E.

    2008-03-01

    Presented in this paper is the development of a novel honeycomb sandwich panel with variable transverse stiffness. In this structure, the traditional sandwich face sheets are replaced by the fluidic flexible matrix composite (F2MC) tube layers developed in recent studies. The F2MC layers, combined with the anisotropic honeycomb core material properties, provide a new sandwich structure with variable stiffness properties for transverse loading. In this research, an analytical model is derived based on Lekhitskii's anisotropic pressurized tube solution and Timoshenko beam theory. Experimental investigations are also conducted to verify the analytical findings. A segmented multiple-F2MC-tube configuration is synthesized to increase the variable stiffness range. The analysis shows that the new honeycomb sandwich structure using F2MC tubes of 10 segments can provide a high/low transverse stiffness ratio of 60. Segmentation and stiffness control can be realized by an embedded valve network, granting a fast response time.

  2. Measurement of the neutron F2 structure function via spectator tagging with CLAS

    CERN Document Server

    Baillie, N; Zhang, J; Bosted, P; Bultmann, S; Christy, M E; Fenker, H; Griffioen, K A; Keppel, C E; Kuhn, S E; Melnitchouk, W; Tvaskis, V; Adhikari, K P; Adikaram, D; Aghasyan, M; Amaryan, M J; Anghinolfini, M; Arrington, J; Avakian, H; Baghdasaryan, H; Battaglieri, M; Biselli, A S; Branford, 5 D; Briscoe, W J; Brooks, W K; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Cole, P L; Contalbrigo, M; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Dey, B; Djalali, C; Dodge, G; Domingo, J; Doughty, D; Dupre, R; Dutta, D; Ent, R; Egiyan, H; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Fradi, A; Gabrielyan, M Y; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Gohn, W; Golovatch, E; Gothe, R W; Graham, L; Guegan, B; Guidal, M; Guler, N; Guo, L; Hafidi, K; Heddle, D; Hicks, K; Holtrop, M; Hungerford, E; Hyde, C E; Ilieva, Y; Ireland, D G; Ispiryan, M; Isupov, E L; Jawalkar, S S; Jo, H S; Kalantarians, N; Khandaker, M; Khetarpal, P; Kim, A; Kim, W; King, P M; Klein, A; Klein, F J; Klimenko, A; Kubarovsky, V; Kuleshov, S V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I J D; Mao, Y; Markov, N; McKinnon, B; Mineeva, T; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Ni, A; Niccolai, S; Niculescu, I; Niculescu, G; Osipenko, M; Ostrovidov, A I; Pappalardo, L; Park, K; Park, S; Pasyuk, E; Pereira, S Anefalos; Pisano, S; Pozdniakov, S; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Raue, B A; Ricco, G; Rimal, D; Ripani, M; Rosner, G; Rossi, P; Sabatie, F; Saini, M S; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Sharabian, Y G; Sober, D I; Sokhan, D; Stepanyan, S; Stepanyan, S S; Stoler, P; Strauch, S; Taiuti, M; Tang, W; Ungaro, M; Vineyard, M F; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zana, L; Zhao, B

    2011-01-01

    We report on the first measurement of the F2 structure function of the neutron from semi-inclusive scattering of electrons from deuterium, with low-momentum protons detected in the backward hemisphere. Restricting the momentum of the spectator protons to < 100 MeV and their angles to < 100 degrees relative to the momentum transfer allows an interpretation of the process in terms of scattering from nearly on-shell neutrons. The F2n data collected cover the nucleon resonance and deep-inelastic regions over a wide range of x for 0.65 < Q2 < 4.52 GeV2, with uncertainties from nuclear corrections estimated to be less than a few percent. These measurements provide the first determination of the neutron to proton structure function ratio F2n/F2p at 0.2 < x < 0.8, essentially free of nuclear corrections.

  3. QCD analysis of neutrino charged current structure function F2 in deep inelastic scattering

    Science.gov (United States)

    Saleem, M.; Aleem, F.

    1985-08-01

    An analytic expression for the neutrino charged current structure function F2 (x, Q2) in deep inelastic scattering, consistent with quantum chromodynamics, is proposed. The calculated results are in good agreement with experiment.

  4. Microstructural and Optical Absorption Properties of Cu-MgF2 Nanoparticle Cermet Film

    Institute of Scientific and Technical Information of China (English)

    孙兆奇; 孙大明; 阮图南

    2002-01-01

    We examine the microstructural and optical absorption spectra of 10-30 vol% Cu-MgF2 nanoparticle cermet films prepared by co-evaporation in vacuum. The results show that the Cu-MgF2 cermet films are mainly composed of the amorphous MgF2 matrix with embedded fcc Cu nanoparticles of average size 12-24 nm. The results also show that the optical absorption of the films decreases as the wavelength increases in the range of 200-800nm. The surface plasmon resonance absorption peaks of Cu nanoparticles in 10, 20 and 30 vo1% Cu-MgF2 films appear at 578, 588 and 606nm, respectively. The interband transition absorption of Cu starts from 590nm downwards.Based on the Maxwell-Garnett theory, the experimental optical absorption properties of the films have been quantitatively evaluated.

  5. Pyometra in Bitches Induces Elevated Plasma Endotoxin and Prostaglandin F2α Metabolite Levels

    National Research Council Canada - National Science Library

    Hagman, R; Kindahl, H; Lagerstedt, A-S

    2006-01-01

    .... Endotoxin samples were taken on five occasions before, during and after surgery. In addition, urine and uterine bacteriology was performed and hematological, blood biochemical parameters, prostaglandin F2α...

  6. As-resistance in laboratory-reared F1, F2 and F3 generation offspring of the earthworm Lumbricus rubellus inhabiting an As-contaminated mine soil

    Energy Technology Data Exchange (ETDEWEB)

    Langdon, C.J., E-mail: clangdon1@btinternet.co [C/O The Open University in the North, Baltic Buiness Quarter, Abbots Hill, Gateshead NE8 3DF (United Kingdom); Morgan, A.J., E-mail: morganaj1@cardiff.ac.u [Cardiff School of Biosciences, Cardiff University, P.O. Box 913, Cardiff CF11 3TL, Wales (United Kingdom); Charnock, J.M., E-mail: john.charnock@manchester.ac.u [STFC Daresbury Laboratory, Warrington, Cheshire WA4 4AD (United Kingdom); School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Semple, K.T., E-mail: k.semple@lancaster.ac.u [Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Lowe, C.N., E-mail: cnlowe@uclan.ac.u [School of Built and Natural Environment, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

    2009-11-15

    Previous studies provided no unequivocal evidence demonstrating that field populations of Lumbricus rubellus Hoffmeister (1843), exhibit genetically inherited resistance to As-toxicity. In this study F1, F2 and F3 generation offspring derived from adults inhabiting As-contaminated field soil were resistant when exposed to 2000 mg kg{sup -1} sodium arsenate. The offspring of uncontaminated adults were not As-resistant. Cocoon viability was 80% for F1 and 82% for F2 offspring from As-contaminated adults and 59% in the F1 control population. High energy synchrotron analysis was used to determine whether ligand complexation of As differed in samples of: resistant mine-site adults, the resistant F1 and F2 offspring of the mine-site earthworms exposed to the LC{sub 25} sodium arsenate (700 mg kg{sup -1}) of the F1 parental generation; and adult L. rubellus from an uncontaminated site exposed to LC{sub 25} concentrations of sodium arsenate (50 mg kg{sup -1}). XANES and EXAFS indicated that As was present as a sulfur-coordinated species. - As-resistance in F1, F2 and F3 offspring of the earthworm Lumbricus rubellus.

  7. Continuous utility factor in segregation models

    Science.gov (United States)

    Roy, Parna; Sen, Parongama

    2016-02-01

    We consider the constrained Schelling model of social segregation in which the utility factor of agents strictly increases and nonlocal jumps of the agents are allowed. In the present study, the utility factor u is defined in a way such that it can take continuous values and depends on the tolerance threshold as well as the fraction of unlike neighbors. Two models are proposed: in model A the jump probability is determined by the sign of u only, which makes it equivalent to the discrete model. In model B the actual values of u are considered. Model A and model B are shown to differ drastically as far as segregation behavior and phase transitions are concerned. In model A, although segregation can be achieved, the cluster sizes are rather small. Also, a frozen state is obtained in which steady states comprise many unsatisfied agents. In model B, segregated states with much larger cluster sizes are obtained. The correlation function is calculated to show quantitatively that larger clusters occur in model B. Moreover for model B, no frozen states exist even for very low dilution and small tolerance parameter. This is in contrast to the unconstrained discrete model considered earlier where agents can move even when utility remains the same. In addition, we also consider a few other dynamical aspects which have not been studied in segregation models earlier.

  8. Racial Segregation and the American Foreclosure Crisis.

    Science.gov (United States)

    Rugh, Jacob S; Massey, Douglas S

    2010-10-01

    Although the rise in subprime lending and the ensuing wave of foreclosures was partly a result of market forces that have been well-identified in the literature, in the United States it was also a highly racialized process. We argue that residential segregation created a unique niche of poor minority clients who were differentially marketed risky subprime loans that were in great demand for use in mortgage-backed securities that could be sold on secondary markets. We test this argument by regressing foreclosure actions in the top 100 U.S. metropolitan areas on measures of black, Hispanic, and Asian segregation while controlling for a variety of housing market conditions, including average creditworthiness, the extent of coverage under the Community Reinvestment Act, the degree of zoning regulation, and the overall rate of subprime lending. We find that black residential dissimilarity and spatial isolation are powerful predictors of foreclosures across U.S. metropolitan areas. In order to isolate subprime lending as the causal mechanism whereby segregation influences foreclosures, we estimate a two-stage least squares model that confirms the causal effect of black segregation on the number and rate of foreclosures across metropolitan areas. In the United States segregation was an important contributing cause of the foreclosure crisis, along with overbuilding, risky lending practices, lax regulation, and the bursting of the housing price bubble.

  9. Neurotransmitter segregation: functional and plastic implications.

    Science.gov (United States)

    Sámano, Cynthia; Cifuentes, Fredy; Morales, Miguel Angel

    2012-06-01

    Synaptic cotransmission is the ability of neurons to use more than one transmitter to convey synaptic signals. Cotransmission was originally described as the presence of a classic transmitter, which conveys main signal, along one or more cotransmitters that modulate transmission, later on, it was found cotransmission of classic transmitters. It has been generally accepted that neurons store and release the same set of transmitters in all their synaptic processes. However, some findings that show axon endings of individual neurons storing and releasing different sets of transmitters, are not in accordance with this assumption, and give support to the hypothesis that neurons can segregate transmitters to different synapses. Here, we review the studies showing segregation of transmitters in invertebrate and mammalian central nervous system neurons, and correlate them with our results obtained in sympathetic neurons. Our data show that these neurons segregate even classic transmitters to separated axons. Based on our data we suggest that segregation is a plastic phenomenon and responds to functional synaptic requirements, and to 'environmental' cues such as neurotrophins. We propose that neurons have the machinery to guide the different molecules required in synaptic transmission through axons and sort them to different axon endings. We believe that transmitter segregation improves neuron interactions during cotransmission and gives them selective and better control of synaptic plasticity.

  10. On the Rise of the Proton Structure Function F_2 Towards Low x

    CERN Document Server

    Adloff, C.; Andrieu, B.; Anthonis, T.; Arkadov, V.; Astvatsatourov, A.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bate, P.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, Christoph; Berndt, T.; Bizot, J.C.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burrage, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cao, Jun; Caron, S.; Clarke, D.; Clerbaux, B.; Collard, C.; Contreras, J.G.; Coppens, Y.R.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dingfelder, J.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Dubak, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Fleming, Y.H.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Foster, J.M.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goodwin, C.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hildebrandt, M.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C .; Jacquet, M.; Jaffre, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kastli, H.K.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Kjellberg, P.; Klein, M.; Kleinwort, C.; Kluge, T.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Koutouev, R.; Koutov, A.; Krehbiel, H.; Kroseberg, J.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Lahmann, R.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebailly, E.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstroem, M.; List, B.; Lobodzinska, E.; Lobodzinski, B.; Loginov, A.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Rabbertz, K.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Risler, C.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Chekelian, V.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Solovev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Straumann, U.; Swart, M.; Tasevsky, M.; Chernyshov, V.; Chetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Urban, Marcel; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vassilev, S.; Vazdik, Y.; Vichnevski, A.; Wacker, K.; Wallny, R.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Werner, C.; Werner, M.; Werner, N.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; Zsembery, J.; zur Nedden, M.

    2001-01-01

    A measurement of the derivative (d ln F_2 / d lnx)_(Q^2)= -lambda(x,Q^2) of the proton structure function F_2 is presented in the low x domain of deeply inelastic positron-proton scattering. For 5*10^(-5)=1.5 GeV^2, lambda(x,Q^2) is found to be independent of x and to increase linearly with ln(Q^2).

  11. Basal Plane Fluorination of Graphene by XeF2 via a Radical Cation Mechanism.

    Science.gov (United States)

    Liu, Yijun; Noffke, Benjamin W; Qiao, Xiaoxiao; Li, Qiqi; Gao, Xinfeng; Raghavachari, Krishnan; Li, Liang-shi

    2015-09-17

    Graphene fluorination with XeF2 is an attractive method to introduce a nonzero bandgap to graphene under mild conditions for potential electro-optical applications. Herein, we use well-defined graphene nanostructures as a model system to study the reaction mechanism of graphene fluorination by XeF2. Our combined experimental and theoretical studies show that the reaction can proceed through a radical cation mechanism, leading to fluorination and sp(3)-hybridized carbon in the basal plane.

  12. Vacuum ultraviolet - photon mediated production of [(18) F]F2.

    Science.gov (United States)

    Krzyczmonik, Anna; Keller, Thomas; Kirjavainen, Anna; Forsback, Sarita; Solin, Olof

    2017-01-25

    The chemistry of F2 and its derivatives are amenable to facile aliphatic or aromatic substitution, as well as electrophilic addition. The main limitation in the use of [(18) F]F2 for radiopharmaceutical synthesis is the low specific activity achieved by the traditional methods of production. The highest specific activities, 55 GBq/µmol, for [(18) F]F2 have been achieved so far by using electrical discharge in the post-target production of [(18) F]F2 gas from [(18) F]CH3 F. We demonstrate that [(18) F]F2 is produced by illuminating a gas mixture of neon/F2 /[(18) F]CH3 F with vacuum ultraviolet (VUV) photons generated by an excimer laser. We tested several illumination chambers and production conditions. The effects of the initial amount of [(18) F]F(-) , amount of carrier F2 and number of 193 nm laser pulses at constant power were evaluated with regard to radiochemical yield and specific activity. The specific activity attained for [(18) F]F2 derived [(18) F]NFSi was 10.3 ± 0.9 GBq/µmol and the average radiochemical yield over a wide range of conditions was 6.7% from [(18) F]F(-) . The production can be improved by optimization of the synthesis device and procedures. The use of a commercially available excimer laser and the simplicity of the process can make this method relatively easy for adaptation in radiochemistry laboratories.

  13. The gluon density of the proton at low x from a QCD analysis of F$_{2}$

    CERN Document Server

    Aïd, S; Andrieu, B; Appuhn, R D; Arpagaus, M; Babaev, A; Ban, Y; Baranov, P S; Barrelet, E; Barschke, R; Bartel, Wulfrin; Barth, Monique; Bassler, U; Beck, H P; Behrend, H J; Belousov, A; Berger, C; Bernardi, G; Bernet, R; Bertrand-Coremans, G H; Besançon, M; Beyer, R; Biddulph, P; Bispham, P; Bizot, J C; Blobel, Volker; Borras, K; Botterweck, F; Boudry, V; Braemer, A; Brasse, F W; Braunschweig, W; Brisson, V; Bruncko, Dusan; Brune, C R; Buchholz, R; Buniatian, A Yu; Burke, S; Burton, M; Buschhorn, G W; Bán, J; Bähr, J; Büngener, L; Bürger, J; Büsser, F W; Campbell, A J; Carli, T; Charles, F; Charlet, M; Chernyshov, V; Clarke, D; Clegg, A B; Clerbaux, B; Colombo, M G; Contreras, J G; Cormack, C; Coughlan, J A; Courau, A; Coutures, C; Cozzika, G; Criegee, L; Cussans, D G; Cvach, J; Dagoret, S; Dainton, J B; Dau, W D; Daum, K; David, M; De Wolf, E A; Del Buono, L; Delcourt, B; Di Nezza, P; Dollfus, C; Dowell, John D; Dreis, H B; Droutskoi, A; Duboc, J; Duhm, H; Düllmann, D; Dünger, O; Ebert, J; Ebert, T R; Eckerlin, G; Efremenko, V; Egli, S; Eichenberger, S; Eichler, R; Eisele, Franz; Eisenhandler, Eric F; Ellison, R J; Elsen, E E; Erdmann, M; Erdmann, W; Erlichmann, H; Evrard, E; Favart, L; Fedotov, A; Feeken, D; Felst, R; Feltesse, Joel; Ferencei, J; Ferrarotto, F; Flamm, K; Fleischer, M; Flieser, M; Flügge, G; Fomenko, A; Fominykh, B A; Forbush, M; Formánek, J; Foster, J M; Franke, G; Fretwurst, E; Gabathuler, Erwin; Gabathuler, K; Garvey, J; Gayler, J; Gebauer, M; Gellrich, A; Genzel, H; Gerhards, R; Glazov, A; Goerlach, U; Gogitidze, N; Goldberg, M; Goldner, D; González-Pineiro, B; Gorelov, I V; Goritchev, P A; Grab, C; Greenshaw, T J; Grindhammer, G; Gruber, A; Gruber, C; Grässler, Herbert; Grässler, R; Görlich, L; Haack, J; Haidt, Dieter; Hajduk, L; Hamon, O; Hampel, M; Hapke, M; Haynes, W J; Heatherington, J; Heinzelmann, G; Henderson, R C W; Henschel, H; Herynek, I; Hess, M F; Hildesheim, W; Hill, P; Hiller, K H; Hilton, C D; Hladky, J; Hoeger, K C; Horisberger, R P; Hudgson, V L; Huet, Patrick; Hufnagel, H; Höppner, M; Hütte, M; Ibbotson, M; Itterbeck, H; Jabiol, M A; Jacholkowska, A; Jacobsson, C; Jaffré, M; Janoth, J; Jansen, T; Johnson, D P; Johnson, L; Jung, H; Jönsson, L B; Kalmus, Peter I P; Kant, D; Kaschowitz, R; Kasselmann, P; Kathage, U; Katzy, J M; Kaufmann, H H; Kazarian, S; Kenyon, Ian Richard; Kermiche, S; Keuker, C; Kiesling, C; Klein, M; Kleinwort, C; Knies, G; Ko, W; Kolanoski, H; Kole, F; Kolya, S D; Korbel, V; Korn, M; Kostka, P; Kotelnikov, S K; Krasny, M W; Krehbiel, H; Krämerkämper, T; Krücker, D; Krüger, U P; Krüner-Marquis, U; Kuhlen, M; Kurca, T; Kurzhöfer, J; Kuznik, B; Köhler, T; Köhne, J H; Küster, H; Lacour, D; Lamarche, F; Lander, R; Landon, M P J; Lange, W; Lanius, P; Laporte, J F; Lebedev, A; Lehner, F; Leverenz, C; Levonian, S; Ley, C; Lindström, G; Link, J; Linsel, F; Lipinski, J; List, B; Lobo, G; Loch, P; Lohmander, H; Lomas, J W; Lubimov, V; López, G C; Lüke, D; Magnussen, N; Malinovskii, E I; Mani, S; Maracek, R; Marage, P; Marks, J; Marshall, R; Martens, J; Martin, G; Martin, R D; Martyn, H U; Martyniak, J; Masson, S; Mavroidis, A; Maxfield, S J; McMahon, S J; Mehta, A; Meier, K; Mercer, D; Merz, T; Meyer, C A; Meyer, H; Meyer, J; Migliori, A; Mikocki, S; Milstead, D; Moreau, F; Morris, J V; Mroczko, E; Murín, P; Müller, G; Müller, K; Nagovitsin, V; Nahnhauer, R; Naroska, Beate; Naumann, T; Newman, P R; Newton, D; Neyret, D; Nguyen, H K; Nicholls, T C; Niebergall, F; Niebuhr, C B; Niedzballa, C; Nisius, R; Nowak, G; Noyes, G W; Nyberg-Werther, M; Oakden, M N; Oberlack, H; Obrock, U; Olsson, J E; Ozerov, D; Panaro, E; Panitch, A; Pascaud, C; Patel, G D; Peppel, E; Phillips, J P; Pichler, C; Pitzl, D; Pope, G; Prell, S; Prosi, R; Pérez, E; Rabbertz, K; Raupach, F; Reimer, P; Reinshagen, S; Ribarics, P; Rick, Hartmut; Riech, V; Riedlberger, J; Riess, S; Rietz, M; Rizvi, E; Robertson, S M; Robmann, P; Roloff, H E; Roosen, R; Rosenbauer, K; Rostovtsev, A A; Rouse, F; Royon, C; Rusakov, S V; Rybicki, K; Rylko, R; Rädel, G; Rüter, K; Sahlmann, N; Sankey, D P C; Schacht, P; Schiek, S; Schleif, S; Schleper, P; Schmidt, D; Schmidt, G; Schröder, V; Schuhmann, E; Schwab, B; Schöning, A; Sciacca, G F; Sefkow, F; Seidel, M; Sell, R; Semenov, A A; Shekelian, V I; Shevyakov, I; Shtarkov, L N; Siegmon, G; Siewert, U; Sirois, Y; Skillicorn, Ian O; Smirnov, P; Smith, J R; Solochenko, V; Soloviev, Yu V; Spiekermann, J; Spielman, S; Spitzer, H; Starosta, R; Steenbock, M; Steffen, P; Steinberg, R; Stella, B; Stephens, K; Stier, J; Stiewe, J; Stolze, K; Strachota, J; Straumann, U; Struczinski, W; Stösslein, U; Sutton, J P; Tapprogge, Stefan; Thiebaux, C; Thompson, G; Truöl, P; Turnau, J; Tutas, J; Uelkes, P; Usik, A; Valkár, S; Valkárová, A; Vallée, C; Van Esch, P; Van Mechelen, P; Van den Plas, D; Vartapetian, A H; Vazdik, Ya A; Verrecchia, P; Villet, G; Wacker, K; Wagener, A; Wagener, M; Walther, A; Weber, G; Weber, M; Wegener, D; Wegner, A; Wellisch, H P; West, L R; Willard, S; Winde, M; Winter, G G; Wittek, C; Wright, A E; Wulff, N; Wünsch, E; Yiou, T P; Zarbock, D; Zhang, Z; Zhokin, A S; Zimmer, M; Zimmermann, W; Zomer, F; Zuber, K; Zácek, J; de Roeck, A; von Schlippe, W

    1995-01-01

    We present a QCD analysis of the proton structure function F_2 measured by the H1 experiment at HERA, combined with data from previous fixed target experiments. The gluon density is extracted from the scaling violations of F_2 in the range 2\\cdot 10^{-4}

  14. A new global model for the ionospheric F2 peak height for radio wave propagation

    Directory of Open Access Journals (Sweden)

    M. M. Hoque

    2012-05-01

    Full Text Available The F2-layer peak density height hmF2 is one of the most important ionospheric parameters characterizing HF propagation conditions. Therefore, the ability to model and predict the spatial and temporal variations of the peak electron density height is of great use for both ionospheric research and radio frequency planning and operation. For global hmF2 modelling we present a nonlinear model approach with 13 model coefficients and a few empirically fixed parameters. The model approach describes the temporal and spatial dependencies of hmF2 on global scale. For determining the 13 model coefficients, we apply this model approach to a large quantity of global hmF2 observational data obtained from GNSS radio occultation measurements onboard CHAMP, GRACE and COSMIC satellites and data from 69 worldwide ionosonde stations. We have found that the model fits to these input data with the same root mean squared (RMS and standard deviations of 10%. In comparison with the electron density NeQuick model, the proposed Neustrelitz global hmF2 model (Neustrelitz Peak Height Model – NPHM shows percentage RMS deviations of about 13% and 12% from the observational data during high and low solar activity conditions, respectively, whereas the corresponding deviations for the NeQuick model are found 18% and 16%, respectively.

  15. Luminescence and scintillation properties of BaF2sbnd Ce transparent ceramic

    Science.gov (United States)

    Luo, Junming; Sahi, Sunil; Groza, Michael; Wang, Zhiqiang; Ma, Lun; Chen, Wei; Burger, Arnold; Kenarangui, Rasool; Sham, Tsun-Kong; Selim, Farida A.

    2016-08-01

    Cerium doped Barium Fluoride (BaF2sbnd Ce) transparent ceramic was fabricated and its luminescence and scintillation properties were studied. The photoluminescence shows the emission peaks at 310 nm and 323 nm and is related to the 5d-4f transitions in Ce3+ ion. Photo peak at 511 keV and 1274 keV were obtained with BaF2sbnd Ce transparent ceramic for Na-22 radioisotopes. Energy resolution of 13.5% at 662 keV is calculated for the BaF2sbnd Ce transparent ceramic. Light yield of 5100 photons/MeV was recorded for BaF2sbnd Ce(0.2%) ceramic and is comparable to its single crystal counterpart. Scintillation decay time measurements shows fast component of 58 ns and a relatively slow component of 434 ns under 662 keV gamma excitation. The slower component in BaF2sbnd Ce(0.2%) ceramic is about 200 ns faster than the STE emission in BaF2 host and is associated with the dipole-dipole energy transfer from the host matrix to Ce3+ luminescence center.

  16. Generation of (F+2)_AH Centres in Sodium Ion Doped KCl:CO^{2-3}

    Science.gov (United States)

    Diaf, M.; Chihi, I.; Hamaïdia, A.; Akrmi, El.

    1996-01-01

    We demonstrate that (F+2)AH centres of KCl may be obtained from crystals doped with K{2}CO{3} and NaCl, grown by the Czochralski method in open atmosphere. The optical properties of (F+2)AH centres thus produced are exactly the same as those of (F+2)AH centres prepared by the usual technique, which involves superoxide doping and a controlled atmosphere. Nous montrons que les centres (F+2)AH de KCl peuvent être obtenus à partir de cristaux dopés par K{2}CO{3} et NaCl, fabriqués par la méthode de Czochralski à l'air libre. Les propriétés optiques des centres (F+2)AH ainsi produits sont exactement les mêmes que celles des centres (F+2)AH préparés par la technique habituelle, qui comporte le dopage par un superoxyde et l'emploi d'une atmosphère contrôlée.

  17. Daytime F2-layer positive storm effect at middle and lower latitudes

    Directory of Open Access Journals (Sweden)

    A. V. Mikhailov

    Full Text Available Daytime F2-layer positive storm effects at middle and lower latitudes in the winter thermosphere are analyzed using AE-C, ESRO-4 neutral gas composition data, ground-based ionosonde observations and model calculations. Different longitudinal sectors marked by the storm onset as 'night-time' and 'daytime' demonstrate different F2-layer positive storm mechanisms. Neutral composition changes in the 'night-time' sector with increased [O] and [N2] absolute concentrations, while (N2/Ostorm/(N2/Oquietapprox1 at F2-layer heights, are shown to contribute largely to the background NmF2 increase at lower latitudes lasting during daytime hours. Storm-induced surges of the equatorward wind give rise to an additional NmF2 increase above this background level. The mid-latitude F2-layer positive storm effect in the 'daytime' sector is due to the vertical plasma drift increase, resulting from the interaction of background (poleward and storm-induced (equatorward thermospheric winds, but not to changes of [O] and [N2] concentrations.

  18. LATS refining ladle slag modifying with CaO-CaF2

    Institute of Scientific and Technical Information of China (English)

    Hongming Wang; Guirong Li; Zhongming Ren; Bo Li; Xuejun Zhang; Guomin Shi

    2007-01-01

    To reduce the slag sticking onto the snorkel of the ladle during the ladle alloying treatment station (LATS) process, CaO-CaF2 (the mass ratio of CaO/CaF2 is 1:1) was employed as the modifier of the LATS refining ladle slag. The effect of CaO-CaF2 on the melting point, viscosity, and desulfurizing capability of the ladle slag was investigated. The melting point of the unmodified ladle slag is 1439°C. When adding 20wt% CaO-CaF2, the melting point is decreased to 1327°C. At 1500°C, the viscosity of the unmodified ladle slag is 6.5 Pa·s, which can be decreased lower than 2 Pa·s by adding more than 10wt% CaO-CaF2. The experimental results of desulfurization of the melts show that the desulfurizing power of the ladle slag can be enhanced by adding CaO-CaF2.

  19. Synthesis and optical characterizations of Nd, Y: CaF2 transparent ceramics

    Science.gov (United States)

    Sun, Zaichun; Mei, Bingchu; Li, Weiwei; Liu, Xiaoya; Su, Liangbi

    2017-09-01

    Highly transparent Nd, Y co-doped calcium fluoride (Nd, Y: CaF2) ceramics with different Y3+ ions doped concentrations were fabricated by hot-pressed method using Nd, Y: CaF2 nanopowders synthesized by co-precipitation method. According to the XRD calculations and SEM observations, the average grain size of nanopowders was about 22 nm. From the SEM micrograph of the nanopowders, it clearly shows that the nanoparticles exhibit nearly spherical morphology and agglomerated slightly. For 2 mm thickness sample, the transmittance of the as-fabricated Nd, Y: CaF2 (1 at.% Nd and 2 at.% Y) ceramic at 1400 nm reached up to 87%. The microstructure, absorption spectra and emission spectra of the Nd, Y: CaF2 ceramics were measured and discussed. Compared with the Nd: CaF2 ceramic, the Nd, Y: CaF2 ceramics fluorescent intensity increased drastically with the increase of Y3+ ions doped concentration.

  20. Segregation of Niobium During Electroslag Remelting Process

    Institute of Scientific and Technical Information of China (English)

    DONG Yan-wu; JIANG Zhou-hua; LI Zheng-bang

    2009-01-01

    Experiment was carried out after the process parameters were calculated by the model previously established.The relationship between interdendritic spacing and local solidification time (LST) mainly determined by process parameters was exposed.Furthermore,the extent of segregation was studied.The results indicate that LST and interdendritic spacing are the largest and the amount of Laves phase as a result of the niobium segregation is the highest in the center of the ingot,whereas the opposite results are obtained at the edge of ingot.The extent of element segregation and the amount of Laves phase can be reduced when appropriate parameters are used.Therefore,the duration of subsequent homogenization treatments for 718 is shortened and the alloy quality is improved.

  1. School Segregation and Racial Academic Achievement Gaps

    Directory of Open Access Journals (Sweden)

    Sean F. Reardon

    2016-09-01

    Full Text Available Although it is clear that racial segregation is linked to academic achievement gaps, the mechanisms underlying this link have been debated since James Coleman published his eponymous 1966 report. In this paper, I examine sixteen distinct measures of segregation to determine which is most strongly associated with academic achievement gaps. I find clear evidence that one aspect of segregation in particular—the disparity in average school poverty rates between white and black students’ schools—is consistently the single most powerful correlate of achievement gaps, a pattern that holds in both bivariate and multivariate analyses. This implies that high-poverty schools are, on average, much less effective than lower-poverty schools and suggests that strategies that reduce the differential exposure of black, Hispanic, and white students to poor schoolmates may lead to meaningful reductions in academic achievement gaps.

  2. Segregating complex sound sources through temporal coherence.

    Directory of Open Access Journals (Sweden)

    Lakshmi Krishnan

    2014-12-01

    Full Text Available A new approach for the segregation of monaural sound mixtures is presented based on the principle of temporal coherence and using auditory cortical representations. Temporal coherence is the notion that perceived sources emit coherently modulated features that evoke highly-coincident neural response patterns. By clustering the feature channels with coincident responses and reconstructing their input, one may segregate the underlying source from the simultaneously interfering signals that are uncorrelated with it. The proposed algorithm requires no prior information or training on the sources. It can, however, gracefully incorporate cognitive functions and influences such as memories of a target source or attention to a specific set of its attributes so as to segregate it from its background. Aside from its unusual structure and computational innovations, the proposed model provides testable hypotheses of the physiological mechanisms of this ubiquitous and remarkable perceptual ability, and of its psychophysical manifestations in navigating complex sensory environments.

  3. Schizophrenia-Like Phenotype Inherited by the F2 Generation of a Gestational Disruption Model of Schizophrenia.

    Science.gov (United States)

    Perez, Stephanie M; Aguilar, David D; Neary, Jennifer L; Carless, Melanie A; Giuffrida, Andrea; Lodge, Daniel J

    2016-01-01

    Both environmental and genetic factors contribute to schizophrenia; however, the exact etiology of this disorder is not known. Animal models are utilized to better understand the mechanisms associated with neuropsychiatric diseases, including schizophrenia. One of these involves gestational administration of methylazoxymethanol acetate (MAM) to induce a developmental disruption, which in turn produces a schizophrenia-like phenotype in post-pubertal rats. The mechanisms by which MAM produces this phenotype are not clear; however, we now demonstrate that MAM induces differential DNA methylation, which may be heritable. Here we demonstrate that a subset of both second (F2) and third (F3) filial generations of MAM-treated rats displays a schizophrenia-like phenotype and hypermethylation of the transcription factor, Sp5. Specifically, ventral tegmental area of dopamine neuron activity was examined using electrophysiology as a correlate for the dopamine hyperfunction thought to underlie psychosis in patients. Interestingly, only a subset of F2 and F3 MAM rats exhibited increases in dopamine neuron population activity, indicating that this may be a unique model with a susceptibility to develop a schizophrenia-like phenotype. An increase in dopamine system function in rodent models has been previously associated with decreases in hippocampal GABAergic transmission. In line with these observations, we found a significant correlation between hippocampal parvalbumin expression and dopamine neuron activity in F2 rats. These data therefore provide evidence that offspring born from MAM-treated rats possess a susceptibility to develop aspects of a schizophrenia-like phenotype and may provide a useful tool to investigate gene-environment interactions.

  4. Socially segregated, sympatric sperm whale clans in the Atlantic Ocean

    Science.gov (United States)

    Bøttcher, Anne; Whitehead, Hal

    2016-01-01

    Sperm whales (Physeter macrocephalus) are unusual in that there is good evidence for sympatric populations with distinct culturally determined behaviour, including potential acoustic markers of the population division. In the Pacific, socially segregated, vocal clans with distinct dialects coexist; by contrast, geographical variation in vocal repertoire in the Atlantic has been attributed to drift. We examine networks of acoustic repertoire similarity and social interactions for 11 social units in the Eastern Caribbean. We find the presence of two socially segregated, sympatric vocal clans whose dialects differ significantly both in terms of categorical coda types produced by each clan (Mantel test between clans: matrix correlation = 0.256; p ≤ 0.001) and when using classification-free similarity which ignores defined types (Mantel test between clans: matrix correlation = 0.180; p ≤ 0.001). The more common of the two clans makes a characteristic 1 + 1 + 3 coda, while the other less often sighted clan makes predominantly regular codas. Units were only observed associating with other units within their vocal clan. This study demonstrates that sympatric vocal clans do exist in the Atlantic, that they define a higher order level of social organization as they do in the Pacific, and suggests that cultural identity at the clan level is probably important in this species worldwide. PMID:27429766

  5. Ionospheric weather: cloning missed foF2 observations for derivation of variability index

    Directory of Open Access Journals (Sweden)

    T. L. Gulyaeva

    2008-02-01

    Full Text Available A techique for filling the gaps of the missing F2-layer critical frequency is proposed and applied for the derivation of the ionospheric weather index, characterizing the degree of disturbance at each particular station. A daily-hourly analysis of ionosonde observations of foF2 for 16 stations at latitude range 37° to 70° N, longitudes of 10° W to 150° E, is performed during the solar minimum, 2006. Missed ionosonde observations are reconstructed by cloning data of another station. The process of gap filling considers hourly values of the F peak density NmF2 (deduced from foF2, normalized to the respective median, and assumes that this ratio remains the same for the parent and cloned data. It is shown that the correlation coefficient between cloned fcF2 and observed foF2 is greater than 0.75 for the positive and negative ionospheric disturbed days during a year at solar minimum, independent of the distance between the stations in high and middle latitudes. The quiet reference is determined as a running daily-hourly median for 27 days, preceding the day of observation calibrated for a seasonal trend with ITU-R foF2 predictions. The hourly deviation DNmF2 is defined as the logarithm of ratio of NmF2/NmF2med. A segmented logarithmic scale of the ionospheric weather index, W, is introduced, so that W=±1 refers to the quiet state, W=±2 to a moderate disturbance, W=±3 to the ionospheric storm, and W=±4 to the extreme or anomalous conditions. The catalog of the ionospheric disturbances for W exceeding ±2 at least during 3 consecutive hours is produced and presented online at the SRC and IZMIRAN web pages. It is found that the moderate disturbance is a prevailing state of the ionospheric weather for all stations. The stormy conditions comprise 1 to 20% of the times which occur more frequently at high latitudes, by night, during equinox and winter.

  6. Ionospheric weather: cloning missed foF2 observations for derivation of variability index

    Science.gov (United States)

    Gulyaeva, T. L.; Stanislwska, I.; Tomasik, M.

    2008-02-01

    A techique for filling the gaps of the missing F2-layer critical frequency is proposed and applied for the derivation of the ionospheric weather index, characterizing the degree of disturbance at each particular station. A daily-hourly analysis of ionosonde observations of foF2 for 16 stations at latitude range 37° to 70° N, longitudes of 10° W to 150° E, is performed during the solar minimum, 2006. Missed ionosonde observations are reconstructed by cloning data of another station. The process of gap filling considers hourly values of the F peak density NmF2 (deduced from foF2), normalized to the respective median, and assumes that this ratio remains the same for the parent and cloned data. It is shown that the correlation coefficient between cloned fcF2 and observed foF2 is greater than 0.75 for the positive and negative ionospheric disturbed days during a year at solar minimum, independent of the distance between the stations in high and middle latitudes. The quiet reference is determined as a running daily-hourly median for 27 days, preceding the day of observation calibrated for a seasonal trend with ITU-R foF2 predictions. The hourly deviation DNmF2 is defined as the logarithm of ratio of NmF2/NmF2med. A segmented logarithmic scale of the ionospheric weather index, W, is introduced, so that W=±1 refers to the quiet state, W=±2 to a moderate disturbance, W=±3 to the ionospheric storm, and W=±4 to the extreme or anomalous conditions. The catalog of the ionospheric disturbances for W exceeding ±2 at least during 3 consecutive hours is produced and presented online at the SRC and IZMIRAN web pages. It is found that the moderate disturbance is a prevailing state of the ionospheric weather for all stations. The stormy conditions comprise 1 to 20% of the times which occur more frequently at high latitudes, by night, during equinox and winter.

  7. Measurement of F_2^ccbar and F_2^bbbar at High Q^2 using the H1 Vertex Detector at HERA

    CERN Document Server

    Aktas, A; Anthonis, T; Asmone, A; Babaev, A; Backovic, S; Bähr, J; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Berndt, T; Bizot, J C; Böhme, J; Boenig, M O; Boudry, V; Bracinik, J; Brisson, V; Broker, H B; Brown, D P; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Caron, S; Cassol-Brunner, F; Cerny, K; Chekelian, V; Contreras, J G; Coppens, Y R; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; Delcourt, B; Demirchyan, R; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dingfelder, J; Dodonov, V; Dubak, A; Duprel, C; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Ellerbrock, M; Elsen, E; Erdmann, M; Erdmann, W; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Ferencei, J; Fleischer, M; Fleischmann, P; Fleming, Y H; Flucke, G; Flügge, G; Fomenko, A; Foresti, I; Formánek, J; Franke, G; Frising, G; Gabathuler, Erwin; Gabathuler, K; Garutti, E; Garvey, J; Gayler, J; Gerhards, R; Gerlich, C; Ghazaryan, S; Ginzburgskaya, S; Görlich, L; Gogitidze, N; Gorbounov, S; Grab, C; Grässler, Herbert; Greenshaw, T; Gregori, M; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Haller, J; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Henshaw, O; Herrera-Corral, G; Herynek, I; Heuer, R D; Hildebrandt, M; Hiller, K H; Hoting, P; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, H; Kant, D; Kapichine, M; Karlsson, M; Katzy, J; Keller, N; Kennedy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Koblitz, B; Korbel, V; Kostka, P; Koutouev, R; Kropivnitskaya, A; Kroseberg, J; Krüger, K; Kuckens, J; Kuhr, T; Landon, M P J; Lange, W; Lastoviicka, T; Laycock, P; Lebedev, A; Leiner, B; Lemrani, R; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; List, B; Lobodzinska, E; Loktionova, N A; López-Fernandez, R; Lubimov, V; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marks, J; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Mikocki, S; Milcewicz-Mika, I; Milstead, D; Mohamed, A; Moreau, F; Morozov, A; Morozov, I; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nagovizin, V; Nankov, K; Naroska, Beate; Naumann, J; Naumann, T; Newman, P R; Niebuhr, C B; Nikiforov, A; Nikitin, D K; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Ossoskov, G; Ozerov, D; Paramonov, A A; Pascaud, C; Patel, G D; Peez, M; Pérez, E; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Pöschl, R; Portheault, B; Povh, B; Raicevic, N; Reimer, P; Reisert, B; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A A; Rurikova, Z; Rusakov, S V; Rybicki, K; Sankey, D P C; Sauvan, E; Schatzel, S; Scheins, J; Schilling, F P; Schleper, P; Schmidt, S; Schmitt, S; Schneider, M; Schoeffel, L; Schöning, A; Schröder, V; Schultz-Coulon, H C; Schwanenberger, C; Sedlak, K; Sefkow, F; Shevyakov, I; Shtarkov, L N; Sirois, Y; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Spitzer, H; Stamen, R; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Uraev, A; Urban, M; Usik, A; Utkin, D; Valkárová, A; Vallée, C; Van Mechelen, P; Van Remortel, N; Vargas, A; Trevino; Vazdik, Ya A; Veelken, C; Vest, A; Vinokurova, S; Volchinski, V; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Werner, N; Wessels, M; Wessling, B; Winter, G G; Wissing, C; Woerling, E E; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhelezov, A; Zhokin, A; Zohrabyan, H G; Zomer, F

    2004-01-01

    Measurements are presented of inclusive charm and beauty cross sections in e^+p collisions at HERA for values of photon virtuality Q^2 > 150 GeV^2 and of inelasticity 0.1 < y < 0.7. The charm and beauty fractions are determined using a method based on the impact parameter, in the transverse plane, of tracks to the primary vertex, as measured by the H1 vertex detector. The data are divided into four regions in Q^2 and Bjorken x, and values for the structure functions F_2^{c\\bar{c}} and F_2^{b\\bar{b}} are obtained. The results are found to be compatible with the predictions of perturbative quantum chromodynamics.

  8. Chemical segregation and self polarisation in ferroelectrics

    Directory of Open Access Journals (Sweden)

    Bernard E. Watts

    2009-06-01

    Full Text Available Chemical partitioning or segregation is commonly encountered in solid-state syntheses. It is driven by compositional, thermal and electric field gradients. These phenomena can be quite extreme in thin films and lead to notable effects on the electrical properties of ferroelectrics. The segregation in ferroelectric thin films will be illustrated and the mechanisms explained in terms of diffusion processes driven by a potential gradient of the oxygen. The hypothesis can also explain self polarisation and imprint in ferroelectric hysteresis.

  9. Housing Systems and Ethnic Spatial Segregation

    DEFF Research Database (Denmark)

    Andersen, Hans Skifter; Andersson, Roger; Wessel, Terje

    in Denmark, Finland, Norway and Sweden are ethnically segmented with high concentrations of immigrants in some forms of tenures (especially social/public housing) and low concentrations in others. The paper shows that the spatial distribution of immigrants is strongly connected with the tenure composition...... of immigrants in social/public housing.......Residential spatial segregation is related to housing markets and housing policies. In this paper, ethnic segregation is compared across four Nordic capitals and explanations for the differences are examined by comparing the housing markets and housing policies of the countries. The housing markets...

  10. Flow and segregation in sheared granular slurries

    Science.gov (United States)

    Barentin, C.; Azanza, E.; Pouligny, B.

    2004-04-01

    We study the behaviour of a granular slurry, i.e., a very concentrated suspension of heavy (denser than the fluid) and polydisperse particles sheared between two parallel-plane circular disks. For small gaps, the slurry behaves as a 2d system with a characteristic radial size segregation of particles. For large gaps, the slurry responds as a 3d system, with considerable vertical segregation and a concomitant 2-phase (fluid, solid) flow structure. The thickness ζ of the fluid phase is the 2d-3d gap crossover. Surprisingly, ζ is found to be nearly unaffected by very large changes in the particle size distribution.

  11. Broadly Tunable Room-temperature Operation Co∶MgF2 Laser%宽调谐室温Co∶MgF2激光器

    Institute of Scientific and Technical Information of China (English)

    崔益本; 张伟; 张增明; 姜芸芸; 纪玉峰; 戎春华

    2001-01-01

    用双折射滤光片不同干涉级次和多组谐振腔镜连续调谐室温Co∶MgF2激光器,波长调谐范围达到1700~2550 nm,在2090 nm峰值波长的输出能量及效率分别为115 mJ和16%.

  12. Atmospheric histories and global emissions of halons H-1211 (CBrClF2), H-1301 (CBrF3), and H-2402 (CBrF2CBrF2)

    Science.gov (United States)

    Vollmer, Martin K.; Mühle, Jens; Trudinger, Cathy M.; Rigby, Matthew; Montzka, Stephen A.; Harth, Christina M.; Miller, Benjamin R.; Henne, Stephan; Krummel, Paul B.; Hall, Bradley D.; Young, Dickon; Kim, Jooil; Arduini, Jgor; Wenger, Angelina; Yao, Bo; Reimann, Stefan; O'Doherty, Simon; Maione, Michela; Etheridge, David M.; Li, Shanlan; Verdonik, Daniel P.; Park, Sunyoung; Dutton, Geoff; Steele, L. Paul; Lunder, Chris R.; Rhee, Tae Siek; Hermansen, Ove; Schmidbauer, Norbert; Wang, Ray H. J.; Hill, Matthias; Salameh, Peter K.; Langenfelds, Ray L.; Zhou, Lingxi; Blunier, Thomas; Schwander, Jakob; Elkins, James W.; Butler, James H.; Simmonds, Peter G.; Weiss, Ray F.; Prinn, Ronald G.; Fraser, Paul J.

    2016-04-01

    We report ground-based atmospheric measurements and emission estimates for the halons H-1211 (CBrClF2), H-1301 (CBrF3), and H-2402 (CBrF2CBrF2) from the AGAGE (Advanced Global Atmospheric Gases Experiment) and the National Oceanic and Atmospheric Administration global networks. We also include results from archived air samples in canisters and from polar firn in both hemispheres, thereby deriving an atmospheric record of nearly nine decades (1930s to present). All three halons were absent from the atmosphere until ˜1970, when their atmospheric burdens started to increase rapidly. In recent years H-1211 and H-2402 mole fractions have been declining, but H-1301 has continued to grow. High-frequency observations show continuing emissions of H-1211 and H-1301 near most AGAGE sites. For H-2402 the only emissions detected were derived from the region surrounding the Sea of Japan/East Sea. Based on our observations, we derive global emissions using two different inversion approaches. Emissions for H-1211 declined from a peak of 11 kt yr-1 (late 1990s) to 3.9 kt yr-1 at the end of our record (mean of 2013-2015), for H-1301 from 5.4 kt yr-1 (late 1980s) to 1.6 kt yr-1, and for H-2402 from 1.8 kt yr-1 (late 1980s) to 0.38 kt yr-1. Yearly summed halon emissions have decreased substantially; nevertheless, since 2000 they have accounted for ˜30% of the emissions of all major anthropogenic ozone depletion substances, when weighted by ozone depletion potentials.

  13. Combined age and segregated kinetic model for industrial-scale penicillin fed-batch cultivation

    NARCIS (Netherlands)

    Wang, Z.F.; Lauwerijssen, M.J.C.; Yuan, J.Q.

    2005-01-01

    This paper proposes a cell age model forPenicillium chrysogenum fed-batch cultivation to supply a qualitative insight into morphology-associated dynamics. The average ages of the segregated cell populations, such as growing cells, non-growing cells and intact productive cells, were estimated by this

  14. Relations between residential and workplace segregation among newly arrived immigrant men and women

    NARCIS (Netherlands)

    Tammaru,T.; Strömgren, M.; Van Ham, M.; Danzer, A.M.

    2016-01-01

    Contemporary cities are becoming more and more diverse in population as a result of immigration. Research shows that while residential neighborhoods are becoming ethnically more diverse within cities, residential segregation from natives has overall remained persistently high. High levels of segrega

  15. The HgF2 Ionic Switch: A Triumph of Electrostatics against Relativistic Odds.

    Science.gov (United States)

    Donald, Kelling J; Kretz, William J; Omorodion, Oluwarotimi

    2015-11-16

    A remarkable transition in the chemical bonding in (HgF2)n clusters as a function of n is identified and characterized. HgF2 is a fascinating material. Certain significant consequences of relativistic effects on the structure of the HgF2 molecule, dimer, and trimer disappear in the extended solid. Relativistic effects in Hg ensure that HgX2 molecules (X≡F, Cl, Br, and I) are linear, rigid, and form weakly bound dimers and trimers held together by weak electrostatic and van der Waals-type forces (unlike ZnX2 and CdX2 systems in which the intermonomer contacts are strong polar covalent bonds). For HgF2, the location and nature of an apparent transition from weak interactions in the smallest (HgF2)n clusters to ionic bonding in the (fluorite) HgF2 extended solid has remained a mystery. Computational evidence obtained at the M06-2X, B97D3, and MP2 levels of theory and reported herein indicate that polar covalent bonding in (HgF2)n begins as early as n=5. For n=2 through to n=13, the transition or switch from weak (primarily dipole-dipole-type) intermonomer interactions to a preference for polar covalent bonding occurs within the range 5

  16. Knockdown of E2F2 inhibits tumorigenicity, but preserves stemness of human embryonic stem cells.

    Science.gov (United States)

    Suzuki, Daniela Emi; Nakahata, Adriana Miti; Okamoto, Oswaldo Keith

    2014-06-01

    Tumorigenicity of human pluripotent stem cells is a major threat limiting their application in cell therapy protocols. It remains unclear, however, whether suppression of tumorigenic potential can be achieved without critically affecting pluripotency. A previous study has identified hyperexpressed genes in cancer stem cells, among which is E2F2, a gene involved in malignant transformation and stem cell self-renewal. Here we tested whether E2F2 knockdown would affect the proliferative capacity and tumorigenicity of human embryonic stem cells (hESC). Transient E2F2 silencing in hESC significantly inhibited expression of the proto-oncogenes BMI1 and HMGA1, in addition to proliferation of hESC, indicated by a higher proportion of cells in G1, fewer cells in G2/M phase, and a reduced capacity to generate hESC colonies in vitro. Nonetheless, E2F2-silenced cells kept expression of typical pluripotency markers and displayed differentiation capacity in vitro. More importantly, E2F2 knockdown in hESC significantly inhibited tumor growth in vivo, which was considerably smaller than tumors generated from control hESC, although displaying typical teratoma traits, a major indicator of pluripotency retention in E2F2-silenced cells. These results suggest that E2F2 knockdown can inhibit hESC proliferation and tumorigenicity without significantly harming stemness, providing a rationale to future protocols aiming at minimizing risks related to therapeutic application of cells and/or products derived from human pluripotent cells.

  17. Lifetime determination of the 5d$^{2}$~$^{3}$F$_{2}$ state in barium using trapped atoms

    CERN Document Server

    De, S; Willmann, L

    2015-01-01

    Magneto-optically trapped atoms enable the determination of lifetimes of metastable states and higher lying excited states like the $\\rm{5d^{2}~^{3}F_{2}}$ state in barium. The state is efficiently populated by driving strong transitions from metastable states within the cooling cycle of the barium MOT. The lifetime is inferred from the increase of MOT fluorescence after the transfer of up to $30\\,\\%$ of the trapped atoms to this state. The radiative decay of the $\\rm{5d^{2}~^{3}F_{2}}$ state cascades to the cooling cycle of the MOT with a probability of $96.0(7)\\,\\%$ corresponding to a trap loss of $4.0(7)\\,\\%$ and its lifetime is determined to $\\rm{160(10)~\\mu s}$. This is in good agreement with the theoretically calculated lifetime of $\\rm{190~\\mu s}$ [J. Phys. B, {\\bf 40}, 227 (2007)]. The determined loss of $4.0(7)\\,\\%$ from the cooling cycle is compared with the theoretically calculated branching ratios. This measurement extends the efficacy of trapped atoms to measure lifetimes of higher, long-lived st...

  18. Evaluación de poblaciones segregantes producidas a partir de cruzamientos entre tomate cultivado y la accesión silvestre PI134418 de Solanum habrochaites var. glabratum resistente al pasador del fruto. Evaluation of segregating populations from crosses between cultivated tomato and PI134418 wild accession of Solanum habrochaites var. glabratum with resistance to the fruit borer.

    Directory of Open Access Journals (Sweden)

    Edwin F. Restrepo S.

    2008-01-01

    Full Text Available Se realizó la evaluación de poblaciones segregantes producidas a partir de cruzamientos entre tomate S. lycopersicum L. cv. maravilla y la accesión silvestre PI134418 de S. habrochaites var. glabratum resistente al pasador del fruto N. elegantalis. Se encontró que hay dominancia de los alelos que disminuyen la expresión del caraacute;cter peso promedio de fruto. El método del retrocruzamiento resultó maacute;s eficiente que el de la autofecundación, para contrarrestar la dominancia de los alelos que codifican por el tamaño pequeño del fruto. Los tricomas y el número promedio de frutos por racimo no ejercieron ningún efecto sobre el ataque de los frutos por parte del pasador; mientras que el peso promedio de fruto sí tuvo efecto importante sobre dicho ataque, de tal manera que el insecto tiende a producir mayor daño a medida que se incrementa el peso promedio de fruto. Las poblaciones RC1 y RC2 se comportaron como las típicas segregantes para los caracteres evaluados y exhibieron amplia variabilidad en los mismos. El método del retrocruzamiento fue efectivo para romper la asociación negativa entre el peso promedio de fruto y la resistencia al insecto. El peso promedio de algunos de los frutos en los recombinantes RC2 fluctuó entre 45.1 y 68.6 g y mostraron resistencia al pasador.Evaluation of segregating populations from crosses between cultivated tomato S. lycopersicum L. cv. maravilla and PI134418 wild accession of Solanum habrochaites var. glabratum with resistance to the fruit borer N. elegantalis was made. There was dominance of alleles that decrease the expression of the character mean fruit weight. The backcrossing method was more efficient than selfing in order to counteract the dominance of alleles that encode by small fruit size. The thrichomes and the mean number of fruit per bunch did not produce any effect on the fruit attack by the fruit borer; while that mean fruit weight had important effect on this attack

  19. Evaluation of segregating populations from crosses between cultivated tomato and PI134418 Evaluación de poblaciones segregantes producidas a partir de cruzamientos entre tomate cultivado y la accesión silvestre PI134418 de Solanum habrochaites var. glabratum resistente al pasador del fruto.

    Directory of Open Access Journals (Sweden)

    Vallejo Cabrera Franco Alirio

    2008-03-01

    Full Text Available Evaluation of segregating populations from crosses between cultivated tomato S. lycopersicum L. cv. maravilla and PI134418 wild accession of Solanum habrochaites var. glabratum with resistance to the fruit borer N. elegantalis was made. There was dominance of alleles that decrease theexpression of the character mean fruit weight. The backcrossing method was more efficient than selfing in order to counteract the dominance of alleles that encode by small fruit size. The thrichomes and the mean number of fruit per bunch did not produce any effect on the fruit attack by the fruit borer; while that mean fruit weight had important effect on this attack, therefore, the insect tends to produce more damage with the increasing in the mean fruit weight. The RC1 and RC2 populations showed segregating typical behavior for evaluated characters, presenting high variability in all of them. The backcrossing method was effective to break the negative association between mean fruit weight and the resistance to the insect. The mean fruit weight in the RC2 recombinant was between 45.1 and 68.6 g and showed resistance to the fruit borer.

    Se realizó la evaluación de poblaciones segregantes producidas a partir de cruzamientos entre tomate S. lycopersicum L. cv. maravilla y la accesión silvestre PI134418 de S. habrochaites var. glabratum resistente al pasador del fruto N. elegantalis. Se encontró que hay dominancia de los alelos que disminuyen la expresión del carácter peso promedio de fruto. El método del retrocruzamiento resultó más eficiente que el de la autofecundación, para contrarrestar la dominancia de los alelos que codifican por el tamaño peque

  20. Trends in the critical frequency foF2 after 2009

    Science.gov (United States)

    Danilov, A. D.; Konstantinova, A. V.

    2016-05-01

    The problem of how the deep minimum of solar activity of 2008-2009 influenced trends in the critical frequency of the F2 layer and whether the negative trends in foF2 are conserved in the following five years is considered in the paper. The initial data series used in previous publications by the authors are completed by data to 2014 (2015). Methods of searching for trends that were described in the past several times by the authors were applied. It was found that, in the vast majority of cases, the monotonous change in the curves used to derive the foF2 trend was distorted in years close to the anomalously low minimum of solar activity in 2008-2009. That decreased the obtained trend in the critical frequency as compared with the results based on the data to 2009. However, subsequent years again lead to a tendency toward monotonous decrease in foF2. The causes of the anomalies indicated above lie apparently in the inadequacy of the solar activity index F10.7 for the description of changes in the aeronomical parameters determining the foF2 behavior in the period of a very deep minimum of activity that is widely described in some publications.

  1. Rare variants in NR2F2 cause congenital heart defects in humans.

    Science.gov (United States)

    Al Turki, Saeed; Manickaraj, Ashok K; Mercer, Catherine L; Gerety, Sebastian S; Hitz, Marc-Phillip; Lindsay, Sarah; D'Alessandro, Lisa C A; Swaminathan, G Jawahar; Bentham, Jamie; Arndt, Anne-Karin; Louw, Jacoba; Low, Jacoba; Breckpot, Jeroen; Gewillig, Marc; Thienpont, Bernard; Abdul-Khaliq, Hashim; Harnack, Christine; Hoff, Kirstin; Kramer, Hans-Heiner; Schubert, Stephan; Siebert, Reiner; Toka, Okan; Cosgrove, Catherine; Watkins, Hugh; Lucassen, Anneke M; O'Kelly, Ita M; Salmon, Anthony P; Bu'lock, Frances A; Granados-Riveron, Javier; Setchfield, Kerry; Thornborough, Chris; Brook, J David; Mulder, Barbara; Klaassen, Sabine; Bhattacharya, Shoumo; Devriendt, Koen; Fitzpatrick, David F; Wilson, David I; Mital, Seema; Hurles, Matthew E

    2014-04-01

    Congenital heart defects (CHDs) are the most common birth defect worldwide and are a leading cause of neonatal mortality. Nonsyndromic atrioventricular septal defects (AVSDs) are an important subtype of CHDs for which the genetic architecture is poorly understood. We performed exome sequencing in 13 parent-offspring trios and 112 unrelated individuals with nonsyndromic AVSDs and identified five rare missense variants (two of which arose de novo) in the highly conserved gene NR2F2, a very significant enrichment (p = 7.7 × 10(-7)) compared to 5,194 control subjects. We identified three additional CHD-affected families with other variants in NR2F2 including a de novo balanced chromosomal translocation, a de novo substitution disrupting a splice donor site, and a 3 bp duplication that cosegregated in a multiplex family. NR2F2 encodes a pleiotropic developmental transcription factor, and decreased dosage of NR2F2 in mice has been shown to result in abnormal development of atrioventricular septa. Via luciferase assays, we showed that all six coding sequence variants observed in individuals significantly alter the activity of NR2F2 on target promoters.

  2. A Social Network Analysis of Occupational Segregation

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian; van der Leij, Marco

    We develop a social network model of occupational segregation between different social groups, generated by the existence of positive inbreeding bias among individuals from the same group. If network referrals are important for job search, then expected homophily in the contact network structure...

  3. Field induced phase segregation in ferrofluids

    NARCIS (Netherlands)

    Kooij, Ernst S.; Galca, A.C.; Poelsema, Bene

    2008-01-01

    We study the phase segregation in magnetite ferrofluids under the influence of an external magnetic field. A phase with lower nanoparticle density and corresponding higher optical transmission is formed in the bottom of a glass cell in the presence of only a very modest magnetic field gradient (smal

  4. Size segregation in a granular bore

    Science.gov (United States)

    Edwards, A. N.; Vriend, N. M.

    2016-10-01

    We investigate the effect of particle-size segregation in an upslope propagating granular bore. A bidisperse mixture of particles, initially normally graded, flows down an inclined chute and impacts with a closed end. This impact causes the formation of a shock in flow thickness, known as a granular bore, to travel upslope, leaving behind a thick deposit. This deposit imprints the local segregated state featuring both pure and mixed regions of particles as a function of downstream position. The particle-size distribution through the depth is characterized by a thin purely small-particle layer at the base, a significant linear transition region, and a thick constant mixed-particle layer below the surface, in contrast to previously observed S-shaped steady-state concentration profiles. The experimental observations agree with recent progress that upward and downward segregation of large and small particles respectively is asymmetric. We incorporate the three-layer, experimentally observed, size-distribution profile into a depth-averaged segregation model to modify it accordingly. Numerical solutions of this model are able to match our experimental results and therefore motivate the use of a more general particle-size distribution profile.

  5. Chromosome Segregation: Organizing Overlap at the Midzone

    NARCIS (Netherlands)

    Janson, M.E.; Tran, P.T.

    2008-01-01

    Sets of overlapping microtubules support the segregation of chromosomes by linking the poles of mitotic spindles. Recent work examines the effect of putting these linkages under pressure by the activation of dicentric chromosomes and sheds new light on the structural role of several well-known spind

  6. Why Are English Secondary Schools Socially Segregated?

    Science.gov (United States)

    Coldron, John; Cripps, Caroline; Shipton, Lucy

    2010-01-01

    This paper seeks an explanation for the persistent social phenomenon of segregated schooling in England whereby children from families with broadly the same characteristics of wealth, education and social networks are more likely to be educated together and therefore separate from children from more socially distant groups. The paper outlines the…

  7. 17 CFR 31.12 - Segregation.

    Science.gov (United States)

    2010-04-01

    ... convenience be commingled with other leverage customer funds and deposited in the same account or accounts....12 Segregation. (a) Any person that accepts leverage customer funds from a leverage customer to enter into or maintain a leverage contract shall treat and deal with such leverage customer funds...

  8. Segregation analysis of urothelial cell carcinoma.

    NARCIS (Netherlands)

    Aben, K.K.H.; Baglietto, L.; Baffoe-Bonnie, A.B.; Coebergh, J.W.W.; Bailey-Wilson, J.E.; Trink, B.; Verbeek, A.L.M.; Schoenberg, M.P.; Witjes, J.A.; Kiemeney, L.A.L.M.

    2006-01-01

    A family history of urothelial cell carcinoma (UCC) confers an almost two-fold increased risk of developing UCC. It is unknown whether (part of) this aggregation of UCC has a Mendelian background. We performed complex segregation analyses on 1193 families ascertained through a proband with UCC of th

  9. Calcifying Sorting and Segregating: "Brown" at 60

    Science.gov (United States)

    Graff, Cristina Santamaria; Kozleski, Elizabeth

    2014-01-01

    The 2007 "Parents Involved in Community Schools v. Seattle School District No. 1". Supreme Court 5:4 decision suggests that the Court is divided in its interpretation of "Brown" and its intent in addressing racial segregation. Although "Brown" intended equal educational opportunities through desegregation practices,…

  10. A segregation analysis of familial achalasia in Iranian population

    NARCIS (Netherlands)

    Malekzadeh, Reza; Amini, Marzyeh; Mikaeli, Javad; Fazlollahi, Narges; Alizadeh, Behrozziad

    2013-01-01

    Objective: Achalasia is a rare primary immune-mediated motor disorder of esophagus with an annual incidence of -1 in 100,000 affecting mostly adult of 25 to 60 years old. The inheritance pattern of Achalasia is not studied very well due to lack of sizable studies. Within a large cohort of Achalasia,

  11. Modeling size segregation of granular materials: the roles of segregation, advection and diffusion

    CERN Document Server

    Fan, Yi; Umbanhowar, Paul B; Ottino, Julio M; Lueptow, Richard M

    2014-01-01

    Predicting segregation of granular materials composed of different-sized particles is a challenging problem. In this paper, we develop and implement a theoretical model that captures the interplay between advection, segregation, and diffusion in size bidisperse granular materials. The fluxes associated with these three driving factors depend on the underlying kinematics, whose characteristics play key roles in determining particle segregation configurations. Unlike previous models for segregation, our model uses parameters based on kinematic measures from discrete element method simulations instead of arbitrarily adjustable fitting parameters, and it achieves excellent quantitative agreement with both experimental and simulation results when applied to quasi-two-dimensional bounded heaps. The model yields two dimensionless control parameters, both of which are only functions of physically control parameters (feed rate, particle sizes, and system size) and kinematic parameters (diffusion coefficient, flowing l...

  12. Solar Cycle variations of ƒoF2 from IGY to 1990

    Directory of Open Access Journals (Sweden)

    M. K. Goel

    Full Text Available Noontime monthly median values of F2-layer critical frequency foF2 (m for some ionospheric stations representing low- and mid-latitudes are examined for their dependence on solar activity for the years 1957 (IGY to 1990. This is the period for which ionospheric data in digital form is available in two CD-ROMs at the World Data Center, Boulder. It is observed that at mid-latitudes, foF2 (m shows nearly a linear relationship with R12 (the 12-month running average of the Zurich sunspot number, though this relation is nonlinear for low-latitudes. These results indicate some departures from the existing information often used in theoretical and applied areas of space research.Key words. Ionosphere (equatorial ionosphere; mid-latitude ionosphere; modelling and forecasting

  13. Sulfide capacities of CaO-CaF2-CaCl2 melts

    Science.gov (United States)

    Simeonov, Simeon; Sakai, Toshihiko; Maeda, Masafumi

    1992-06-01

    The sulfide capacityC_{s^{2 - } } = ({text{pct S}}^{{text{2 - }}} )(p_{{text{O}}_{text{2}} } /p_{{text{S}}_{text{2}} } )^{1/2} ) of CaO-CaF2-CaCl2 slag was determined at temperatures from 1000 °C to 1300 °C by equilibrating molten slag, molten silver, and CO-CO2-Ar gas mixture. The sulfide capacity increases with replacing CaCl2 by CaF2 in slags of constant CaO contents. The sulfide capacity also increases with increasing temperature as well as with increasing CaO content at a constant ratio of CaF2/CaCl2 of unity. A linear relationship between the sulfide capacity and carbonate capacity in literature was observed on a logarithmic scale.

  14. Role of MgF2 on properties of glass–ceramics

    Indian Academy of Sciences (India)

    M Ghasemzadeh; A Nemati

    2012-10-01

    Formation of machinable glass–ceramic in the system MgO–SiO2–Al2O3–K2O–B2O3–F with and without addition of MgF2 has been investigated. Crystallization of glass sample was done by controlled thermal heat treatment at nucleation and crystallization temperatures. The results showed that MgF2 in high concentration had a synergistic effect and enhanced the formation of interlockedmica crystals. Non-isothermal DTA experiments showed that the crystallization activation energies of base glasses were changed in the range of 235–405 kJ/mol, while the crystallization activation energies of samples with addition of MgF2 were changed in the range of 548–752 kJ/mol.

  15. Behavior of Parameters of Nighttime Electron Density Enhancements of the Ionospheric F2 Layer

    Science.gov (United States)

    Yakovets, Artur; Gordienko, Galina

    2017-04-01

    There is known a wide class of disturbances of the F2-layer of the ionosphere, which are superimposed on the regular diurnal variations of the electron density. Different types of disturbances are characterized by different mechanisms of their generation. Traveling ionospheric disturbances appear to be the most characteristic features of the inhomogeneous structure of the ionosphere. Another type of ionospheric disturbances presents the nighttime electron density enhancements in the ionospheric F2- layer maximum (NmF2). This type of irregularities is described in numerous papers. There is a concept that, in spite of the various mechanisms of ionospheric disturbances generation a response of F2-layer parameters exhibits similar features associated with the upward lift and the simultaneous expansion of the layer and then its subsequent downward movement, including layer compression, which results in the formation of the electron density peak in the layer maximum at the moment of greatest compression. The aim of this study is a verification of this concept on the example of disturbances related with the nighttime electron density enhancements, and the definition of precise quantitative relationships between the variations of different F2-layer parameters for such disturbances. By using the data of the ionospheric vertical sounding in Almaty, (76° 55'E, 43°15'N) during 2001-2012, analysis of the behavior the F2-layer parameters during the night electron density enhancements was carried out within framework of a single concept of effects of various types of ionospheric plasma perturbations in variations of height and half-thickness of the F2-layer, accompanied by increasing and decreasing NmF2 at moments of maximum compression and expansion of the layer. For a quantitative analysis of the parameters of nighttime enhancements we have selected 20 nights characterized by low magnetic activity (Dst> - 50 nT) and evident manifestations of the nighttime electron density

  16. Microwave, High-Resolution Infrared, and Quantum Chemical Investigations of CHBrF2

    DEFF Research Database (Denmark)

    Cazzoli, Gabriele; Cludi, Lino; Puzzarini, Cristina

    2011-01-01

    analysis by high-level quantum chemical calculations at the coupled-cluster level. In this context, the importance of relativistic effects, which are of the order of 6.5% and included in the present work using second-order direct perturbation theory, needs to be emphasized for accurate predictions......A combined microwave, infrared, and computational investigation of CHBrF2 is reported. For the vibrational ground state, measurements in the millimeter- and sub-millimeter-wave regions for (CHBrF2)-Br-79 and (CHBrF2)-Br-81 provided rotational and centrifugal-distortion constants up to the sextic...... terms as well as the hyperfine parameters (quadrupole-coupling and spin-rotation interaction constants) of the bromine nucleus. The determination of the latter was made possible by recording of spectra at sub-Doppler resolution, achieved by means of the Lamb-dip technique, and supporting the spectra...

  17. F2∑+-X2∑+ Band System of Cobalt Carbide

    Institute of Scientific and Technical Information of China (English)

    Jing-ru Guo; Zhao-xia Zhang; Ting-ting Wang; Cong-xiang Chen; Yang Chen

    2008-01-01

    The laser-induced fluorescence excitation spectrum of CoC was recorded in the spectral region from 13500 cm-1 to 22000 cm-1, in which the CoC molecules were produced by the reaction of sputtered cobalt atoms with methanol under supersonic jet cooled conditions. Much of the visible spectrum was assigned to transitions between the X2∑+ ground state and F2∑+ state. The 11 bands assigned as (v1=3-13, 0) transi-tions of the F2∑+-X2∑+ band system were observed and rotationally analyzed. Equilibrium constants for the F2∑+ state were Te=13628 cm-1,w,e=669 cm-1,weXe=4.3 cm-1, Be=0.546 cm-1, and Re=1.758 A. Some new bands were observed.

  18. Analysis of laser durability of CaF2 for optical lithography

    Science.gov (United States)

    Grabosch, Guenter; Parthier, Lutz; Natura, Ute; Poehl, Karin; Letz, Martin; Muehlig, Christian; Knapp, Konrad

    2005-02-01

    Photolithography is a key technolgoy for the production of semiconductor devices. It supports the continuing trend towards higher integration density of microelectronic devices. The material used in the optics of lithography tools has to be of extremely high quality to ensure the high demand of the imaging. Due to its properties CaF2 is a material of choice for the application in lithography systems. Because of the compexity of the lithography tools single lenses or lens system modules cannot be replaced. Therefore the lens material has to last the full lifetime of the tool without major degradation. According to the roadmap for next generation of optical lithography tools, like immersion lithography, the requirements of CaF2 for radiation hardness are increasing considerably. We will present a detailed analysis of the key factors influencing the laser hardness covering the complete production chain. Some aspects of the evaluation methods for testing CaF2 laser durability will be presented.

  19. Measurement of the electron structure function F2e at LEP energies

    Directory of Open Access Journals (Sweden)

    J. Abdallah

    2014-10-01

    Full Text Available The hadronic part of the electron structure function F2e has been measured for the first time, using e+e− data collected by the DELPHI experiment at LEP, at centre-of-mass energies of s=91.2–209.5 GeV. The data analysis is simpler than that of the measurement of the photon structure function. The electron structure function F2e data are compared to predictions of phenomenological models based on the photon structure function. It is shown that the contribution of large target photon virtualities is significant. The data presented can serve as a cross-check of the photon structure function F2γ analyses and help in refining existing parameterisations.

  20. A measurement of the proton structure function F$_{2}$(x,Q$^{2}$)

    CERN Document Server

    Ahmed, T; Andreev, V; Andrieu, B; Appuhn, R D; Arpagaus, M; Aïd, S; Babaev, A; Baranov, P S; Barrelet, E; Bartel, Wulfrin; Barth, Monique; Bassler, U; Beck, H P; Behrend, H J; Belousov, A; Berger, C; Bergstein, H; Bernardi, G; Bernet, R; Bertrand-Coremans, G H; Besançon, M; Beyer, R; Bizot, J C; Blobel, Volker; Borras, K; Botterweck, F; Boudry, V; Braemer, A; Brasse, F W; Braunschweig, W; Brisson, V; Bruncko, Dusan; Brune, C R; Buchholz, R; Buniatian, A Yu; Burke, S; Burton, M; Buschhorn, G W; Bán, J; Bähr, J; Büngener, L; Bürger, J; Büsser, F W; Campbell, A J; Carli, T; Charles, F; Chernyshov, V; Clarke, D; Clegg, A B; Clerbaux, B; Colombo, M G; Contreras, J G; Cormack, C; Coughlan, J A; Courau, A; Coutures, C; Cozzika, G; Criegee, L; Cussans, D G; Cvach, J; Dagoret, S; Dainton, J B; Danilov, M V; Dau, W D; Daum, K; David, M; De Wolf, E A; Deffur, E; Del Buono, L; Delcourt, B; Di Nezza, P; Dollfus, C; Dowell, John D; Dreis, H B; Droutskoi, A; Duboc, J; Duhm, H; Düllmann, D; Dünger, O; Ebert, J; Ebert, T R; Eckerlin, G; Efremenko, V; Egli, S; Eichenberger, S; Eichler, R; Eisele, Franz; Eisenhandler, Eric F; Ellison, R J; Elsen, E E; Erdmann, M; Erdmann, W; Erlichmann, H; Evrard, E; Favart, L; Fedotov, A; Feeken, D; Felst, R; Feltesse, Joel; Ferencei, J; Ferrarotto, F; Flamm, K; Fleischer, M; Flieser, M; Flügge, G; Fomenko, A; Fominykh, B A; Forbush, M; Formánek, J; Foster, J M; Franke, G; Fretwurst, E; Gabathuler, Erwin; Gabathuler, K; Gamerdinger, K; Garvey, J; Gayler, J; Gebauer, M; Gellrich, A; Genzel, H; Gerhards, R; Goerlach, U; Gogitidze, N; Goldberg, M; Goldner, D; González-Pineiro, B; Gorelov, I V; Goritchev, P A; Grab, C; Greenshaw, T J; Grindhammer, G; Gruber, A; Gruber, C; Grässler, Herbert; Grässler, R; Görlich, L; Haack, J; Haidt, Dieter; Hajduk, L; Hamon, O; Hampel, M; Hanlon, E M; Hapke, M; Haynes, W J; Heatherington, J; Heinzelmann, G; Henderson, R C W; Henschel, H; Herynek, I; Hess, M F; Hildesheim, W; Hill, P; Hiller, K H; Hilton, C D; Hladky, J; Hoeger, K C; Horisberger, R P; Hudgson, V L; Huet, Patrick; Hufnagel, H; Höppner, M; Hütte, M; Ibbotson, M; Itterbeck, H; Jabiol, M A; Jacholkowska, A; Jacobsson, C; Jaffré, M; Janoth, J; Jansen, T; Johannsen, K; Johnson, D P; Johnson, L; Jung, H; Jönsson, L B; Kalmus, Peter I P; Kant, D; Kaschowitz, R; Kasselmann, P; Kathage, U; Katzy, J M; Kaufmann, H H; Kazarian, S; Kenyon, Ian Richard; Kermiche, S; Keuker, C; Kiesling, C; Klein, M; Kleinwort, C; Knies, G; Ko, W; Kolanoski, H; Kole, F; Kolya, S D; Korbel, V; Korn, M; Kostka, P; Kotelnikov, S K; Krasny, M W; Krehbiel, H; Krämerkämper, T; Krücker, D; Krüger, U P; Krüner-Marquis, U; Kubenka, J P; Kuhlen, M; Kurca, T; Kurzhöfer, J; Kuznik, B; Köhler, T; Köhne, J H; Küster, H; Lacour, D; Lamarche, F; Lander, R; Landon, M P J; Lange, W; Lanius, P; Laporte, J F; Lebedev, A; Leverenz, C; Levonian, S; Ley, C; Lindner, A; Lindström, G; Linsel, F; Lipinski, J; List, B; Loch, P; Lohmander, H; Lubimov, V; López, G C; Lüke, D; Magnussen, N; Malinovskii, E I; Mani, S; Maracek, R; Marage, P; Marks, J; Marshall, R; Martens, J; Martin, R D; Martyn, H U; Martyniak, J; Masson, S; Mavroidis, A; Maxfield, S J; McMahon, S J; Mehta, A; Meier, K; Mercer, D; Merz, T; Meyer, C A; Meyer, H; Meyer, J; Mikocki, S; Milstead, D; Moreau, F; Morris, J V; Mroczko, E; Murín, P; Müller, G; Müller, K; Nagovitsin, V; Nahnhauer, R; Naroska, Beate; Naumann, T; Newman, P R; Newton, D; Neyret, D; Nguyen, H K; Nicholls, T C; Niebergall, F; Niebuhr, C B; Nisius, R; Nowak, G; Noyes, G W; Nyberg-Werther, M; Oakden, M N; Oberlack, H; Obrock, U; Olsson, J E; Panaro, E; Panitch, A; Pascaud, C; Patel, G D; Peppel, E; Phillips, J P; Pichler, C; Pitzl, D; Pope, G; Prell, S; Prosi, R; Pérez, E; Raupach, F; Reimer, P; Reinshagen, S; Ribarics, P; Rick, Hartmut; Riech, V; Riedlberger, J; Riess, S; Rietz, M; Rizvi, E; Robertson, S M; Robmann, P; Roloff, H E; Roosen, R; Rosenbauer, K; Rostovtsev, A A; Rouse, F; Royon, C; Rusakov, S V; Rybicki, K; Rylko, R; Rädel, G; Rüter, K; Sahlmann, N; Sankey, D P C; Savitsky, M M; Schacht, P; Schiek, S; Schleper, P; Schmidt, C; Schmidt, D; Schmidt, G; Schröder, V; Schuhmann, E; Schwab, B; Schwind, A; Schöning, A; Seehausen, U; Sefkow, F; Seidel, M; Sell, R; Semenov, A A; Shekelian, V I; Shevyakov, I; Shooshtari, H; Shtarkov, L N; Siegmon, G; Siewert, U; Sirois, Y; Skillicorn, Ian O; Smirnov, P; Smith, J R; Soloviev, Yu V; Spiekermann, J; Spitzer, H; Starosta, R; Steenbock, M; Steffen, P; Steinberg, R; Stella, B; Stephens, K; Stier, J; Stiewe, J; Strachota, J; Straumann, U; Struczinski, W; Stösslein, U; Sutton, J P; Sánchez, E; Tapprogge, Stefan; Taylor, R E; Thiebaux, C; Thompson, G; Truöl, P; Turnau, J; Tutas, J; Uelkes, P; Usik, A; Valkár, S; Valkárová, A; Vallée, C; Van Esch, P; Van Mechelen, P; Vartapetian, A H; Vazdik, Ya A; Vecko, M; Verrecchia, P; Villet, G; Wacker, K; Wagener, A; Wagener, M; Walker, I W; Walther, A; Weber, G; Weber, M; Wegener, D; Wegner, A; Wellisch, H P; West, L R; Willard, S; Winde, M; Winter, G G; Wright, A E; Wulff, N; Wünsch, E; Yiou, T P; Zarbock, D; Zhang, Z; Zhokin, A S; Zimmer, M; Zimmermann, W; Zomer, F; Zuber, K; Zácek, J; de Roeck, A; von Schlippe, W; Niebergall, Friedrich

    1995-01-01

    A measurement of the proton structure function F_{\\!2}(x,Q^2) is reported for momentum transfer squared Q^2 between 4.5 GeV^2 and 1600 GeV^2 and for Bjorken x between 1.8\\cdot10^{-4} and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that F_{\\!2} increases significantly with decreasing x, confirming our previous measurement made with one tenth of the data available in this analysis. The Q^2 dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to F_{\\!2}.

  1. Optical constants and their dispersion of Ag-MgF2 nanoparticle composite films

    Institute of Scientific and Technical Information of China (English)

    Zhaoqi Sun(孙兆奇); Daming Sun(孙大明)

    2004-01-01

    Ag-MgF2 composite films with different Ag fractions were prepared through a co-evaporation method.Microstructure analysis shows that the films are composed of amorphous MgF2 matrix and embedded fcc-Ag nanoparticles. The optical constants and their dispersion of the films, within the wavelength range of 250 - 650 nm, were measured by reflecting spectroscopic ellipsometry. The maximum of the imaginary part ε" of the complex dielectric permittivity attributing to the surface plasmon resonance polarization of the Ag nanoparticles in an Ag-MgF2 film, and the tangent of the phase-shift angle δ resulting from the dielectric loss of the film, occur at λ = 435 nm and λ = 420 nm, respectively. Based on Maxwell-Garnett effective medium theory, the experimentally observed dispersion spectra were reasonably described.

  2. Absence of systemic oxidative stress and increased CSF prostaglandin F2α in progressive MS

    DEFF Research Database (Denmark)

    Lam, Magda A.; Maghzal, Ghassan J.; Khademi, Mohsen

    2016-01-01

    Objective: We aimed to investigate the role of oxidative stress in the progression of multiple sclerosis (MS).  Methods: We determined by liquid chromatography-tandem mass spectrometry nonenzymatic (F2-isoprostanes) and enzymatic oxidation products of arachidonic acid (prostaglandin F2α [PGF2α......]) in plasma and CSF of 45 controls (other neurologic disease [OND] with no signs of inflammation) and 62 patients with MS. Oxidation products were correlated with disease severity and validated biomarkers of inflammation (chemokine ligand 13; matrix metalloproteinase-9; osteopontin) and axonal damage...... (neurofilament light protein).  Results: Compared with OND controls, plasma concentrations of F2-isoprostanes and PGF2α were significantly lower in patients with progressive disease, and decreased with increasing disability score (Expanded Disability Status Scale). In contrast, CSF concentrations of PGF2α...

  3. Land Markets and its Effects on the Spatial Segregation: The Case of Ciudad Juarez, Mexico

    Directory of Open Access Journals (Sweden)

    César M. Fuentes

    2006-01-01

    Full Text Available The objective of this article is to analyze the land market imperfec-tions and their effect on spatial segregation. It uses a spatial approach through the construction of socio-spatial segregation and infrastructure deficit indexes. The principal component element was used to estimate the socio-spatial in-dexes at the AGEB scale. The data used to calculate the indexes was obtained from the XII Population and Housing Census at census tracts level. The result show that the city suffers from spatial segregation caused mainly by land market imperfections. The land market is not able to ensure an adequate supply at affordable prices and as a result, the biggest sufferers have been the urban poor. The lack of access to urban land has pushed low income inhabitants to the outer limits of the urban core: low value areas without public infrastructure.

  4. Control on Housing Segregation:Housing Modes and Public Policies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>1. Housing segregation:advocating or controlling?The phenomenon of housing segregation has become more and more obvious in Chinese cities in recent years; however, there is no agreement on whether it should

  5. Investigations on transgenerational epigenetic response down the male line in F2 pigs.

    Science.gov (United States)

    Braunschweig, Martin; Jagannathan, Vidhya; Gutzwiller, Andreas; Bee, Giuseppe

    2012-01-01

    We investigated the nutritional effects on carcass traits, gene expression and DNA methylation in a three generation Large White pig feeding experiment. A group of experimental (E) F0 boars were fed a standard diet supplemented with high amounts of methylating micronutrients whereas a control group (C) of F0 boars received a standard diet. These differentially fed F0 boars sired F1 boars which then sired 60 F2 pigs. Carcass traits were compared between 36 F2 descendants of E F0 boars and 24 F2 descendants of C F0 boars. The two F2 offspring groups differed with respect to backfat percentage (P = 0.03) and tended to differ with respect to adipose tissue (P = 0.09), fat thickness at the 10(th) rib (P = 0.08) and at the croup (P = 0.09) as well as percentages of shoulder (P = 0.07). Offspring from the experimental F0 boars had a higher percentage of shoulder and were leaner compared to the control group. Gene expression profiles showed significant twofold differences in mRNA level between 8 C F2 offspring and 8 E F2 offspring for 79, 64 and 53 genes for muscle, liver and kidney RNA, respectively. We found that in liver and muscle respective pathways of lipid metabolism and metabolic pathway were over-represented for the differentially expressed genes between these groups. A DNA methylation analysis in promoters of differentially expressed genes indicated a significant difference in DNA methylation at the IYD gene. If these responses on carcass traits, gene expression and DNA methylation withstand verification and can indeed be attributed to transgenerational epigenetic inheritance, it would open up pioneering application in pork production and would have implications for human health.

  6. Investigations on transgenerational epigenetic response down the male line in F2 pigs.

    Directory of Open Access Journals (Sweden)

    Martin Braunschweig

    Full Text Available We investigated the nutritional effects on carcass traits, gene expression and DNA methylation in a three generation Large White pig feeding experiment. A group of experimental (E F0 boars were fed a standard diet supplemented with high amounts of methylating micronutrients whereas a control group (C of F0 boars received a standard diet. These differentially fed F0 boars sired F1 boars which then sired 60 F2 pigs. Carcass traits were compared between 36 F2 descendants of E F0 boars and 24 F2 descendants of C F0 boars. The two F2 offspring groups differed with respect to backfat percentage (P = 0.03 and tended to differ with respect to adipose tissue (P = 0.09, fat thickness at the 10(th rib (P = 0.08 and at the croup (P = 0.09 as well as percentages of shoulder (P = 0.07. Offspring from the experimental F0 boars had a higher percentage of shoulder and were leaner compared to the control group. Gene expression profiles showed significant twofold differences in mRNA level between 8 C F2 offspring and 8 E F2 offspring for 79, 64 and 53 genes for muscle, liver and kidney RNA, respectively. We found that in liver and muscle respective pathways of lipid metabolism and metabolic pathway were over-represented for the differentially expressed genes between these groups. A DNA methylation analysis in promoters of differentially expressed genes indicated a significant difference in DNA methylation at the IYD gene. If these responses on carcass traits, gene expression and DNA methylation withstand verification and can indeed be attributed to transgenerational epigenetic inheritance, it would open up pioneering application in pork production and would have implications for human health.

  7. What is the degree of segregation between striatonigral and striatopallidal projections?

    Directory of Open Access Journals (Sweden)

    Jesus eBertran-Gonzalez

    2010-10-01

    Full Text Available In contrast to most other brain regions, in the striatum the output neurons (the medium-sized spiny neurons, MSNs are GABAergic and act by inhibiting their targets. The standard model of the basal ganglia is built on the segregation of information processing in the direct and indirect pathways, which act in opposing directions to control movement. The MSNs participating in these two pathways can be identified according to their projection sites and the proteins they express. The differential expression of two of the five known dopamine receptor subtypes, D1 and D2, in the two populations of MSNs is of particular importance, since it confers to dopamine the ability to exert opposite functional modulation on the direct and indirect pathways. However, beyond this simple view of the striatal output organization, anatomical studies questioned the segregation of direct and indirect projections to the SNr, while other studies disclosed variable degrees of overlapping expression of dopamine receptor subtypes in striatal MSNs. New ways to address these issues have emerged recently, using mouse models in which specific populations of striatal neurons are genetically tagged. Here, we review classical and recent studies supporting the segregation of striatonigral and striatopallidal neurons. We also consider this issue at a functional level by focusing on the regulation of striatal signaling pathways in the two populations of MSNs, which clearly emphasize their profound differences. We discuss the anatomical and functional evidence challenging some aspects of this segregation and outline questions that are still to be addressed.

  8. Analysis of meiotic segregation, using single-sperm typing: Meiotic drive at the myotonic dystrophy locus

    Energy Technology Data Exchange (ETDEWEB)

    Leeflang, E.P.; Arnheim, N. [Univ. of Southern California, Los Angeles, CA (United States); McPeek, M.S. [Univ. of Chicago, IL (United States)

    1996-10-01

    Meiotic drive at the myotonic dystrophy (DM) locus has recently been suggested as being responsible for maintaining the frequency, in the human population, of DM chromosomes capable of expansion to the disease state. In order to test this hypothesis, we have studied samples of single sperm from three individuals heterozygous at the DM locus, each with one allele larger and one allele smaller than 19 CTG repeats. To guard against the possible problem of differential PCR amplification rates based on the lengths of the alleles, the sperm were also typed at another closely linked marker whose allele size was unrelated to the allele size at the DM locus. Using statistical models specifically designed to study single-sperm segregation data, we find no evidence of meiotic segregation distortion. The upper limit of the two-sided 95% confidence interval for the estimate of the common segregation probability for the three donors is at or below .515 for all models considered, and no statistically significant difference from .5 is detected in any of the models. This suggests that any greater amount of segregation distortion at the myotonic dystrophy locus must result from events following sperm ejaculation. The mathematical models developed make it possible to study segregation distortion with high resolution by using sperm-typing data from any locus. 26 refs., 1 fig., 8 tabs.

  9. Dispersive calculation of complex Regge trajectories for the lightest $f_2$ resonances

    CERN Document Server

    Carrasco, J A; Pelaez, J R; Szczepaniak, A P

    2015-01-01

    We apply a recently developed dispersive formalism to calculate the Regge trajectories of the $f_2(1270)$ and $f_2'(1525)$ mesons. Trajectories are calculated, not fitted to a family of resonances. Assuming that these spin-2 resonances can be treated in the elastic approximation the only input are the pole position and residue of the resonances. In both cases, the predicted Regge trajectories are almost real and linear, with slopes in agreement with the universal value of order 1 GeV$^{-2}$.

  10. Luminescent and kinetic properties of the polystyrene composites based on BaF2 nanoparticles

    Science.gov (United States)

    Demkiv, T. M.; Halyatkin, O. O.; Vistovskyy, V. V.; Gektin, A. V.; Voloshinovskii, A. S.

    2016-02-01

    Luminescence-kinetic properties of polystyrene composites based on BaF2 nanoparticles were studied. The electron emission from the nanoparticles due to the photoelectric effect is the main luminescence excitation mechanism in the case of polystyrene composites loaded with small BaF2 nanoparticles (~20 nm). Scintillation pulse of polystyrene composites possesses only fast decay component with the time constant τ~2 ns, and its emission intensity considerably exceeds the one for pure polystyrene scintillator upon the X-ray excitations.

  11. Low lying baryon spectrum with N{sub f}=2+1+1 dynamical twisted quarks

    Energy Technology Data Exchange (ETDEWEB)

    Drach, Vincent; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Carbonell, Jaume; Papinutto, Mauro [UJF, CNRS/IN2P3, INPG (France). Lab. de Physique Subatomique et de Cosmologie; Alexandrou, Constantia [Cyprus Univ., Nicosia (Cyprus). Dept. of Physics

    2010-12-15

    We present first results on the octet and decuplet strange baryon spectrum with N{sub f}=2+1+1 twisted mass quarks. We use an Osterwalder Seiler valence strange quark with a mass tuned to the kaon and compare the results with those obtained in the unitary setup. This comparison allows to perform a first study of the lattice artefacts introduced by the mixed action approach. We investigate the effect of the strange and charm quarks in the sea by using two lattice spacings and comparing with preceding N{sub f}=2 twisted mass fermion calculations. (orig.)

  12. Crystal structure of bis(fluorosulfato-κOxenon(II, Xe(SO3F2

    Directory of Open Access Journals (Sweden)

    Moritz Malischewski

    2015-04-01

    Full Text Available Thermally unstable Xe(SO3F2 has been prepared by the reaction of XeF2 with HSO3F. Single crystals were obtained from HSO3F by slow cooling in a sealed tube. The molecular structure is characterized by the Xe atom covalently bonded to two O atoms of two fluorosulfate tetrahedra in an almost linear fashion [O—Xe—O = 179.13 (4°]. The crystal packing is strongly influenced by intermolecular van der Waals forces.

  13. Low lying baryon spectrum with $N_f = 2+1+1$ dynamical twisted quarks

    CERN Document Server

    Drach, Vincent; Carbonell, Jaume; Papinutto, Mauro; Alexandrou, Constantia

    2010-01-01

    We present first results on the octet and decuplet strange baryon spectrum with $N_f=2+1+1$ twisted mass quarks. We use an Osterwalder Seiler valence strange quark with a mass tuned to the kaon and compare the results with those obtained in the unitary setup. This comparison allows to perform a first study of the lattice artefacts introduced by the mixed action approach. We investigate the effect of the strange and charm quarks in the sea by using two lattice spacings and comparing with preceding $N_f = 2$ twisted mass fermion calculations.

  14. Vertical motions of the midlatitude F2 layer during magnetospheric substorms.

    Science.gov (United States)

    Park, C. G.; Meng, C.

    1971-01-01

    Use of ground-based ionosonde records from midlatitude stations during winter nights to study vertical motions of the F2 layer associated with magnetospheric substorms. The results show that during substorms the F2 layer is lifted upward in the premidnight sector and pushed downward in the postmidnight sector. These motions are interpreted in terms of E x B drifts, the electric field being eastward on the eveningside and westward on the morningside. The results emphasize the importance of substorm effects on the midlatitude F region and the potential of ground-based hf sounding techniques in studying magnetospheric substorms.

  15. A Perturbative QCD Analysis of the Nucleon's Pauli Form Factor F_2(Q^2)

    CERN Document Server

    Belitsky, A V; Yuan, F; Belitsky, Andrei V.; Ji, Xiangdong; Yuan, Feng

    2003-01-01

    We perform a perturbative QCD analysis of the nucleon's Pauli form factor $F_2(Q^2)$ in the asymptotically large $Q^2$ limit. We find that the leading contribution to $F_2(Q^2)$ goes like $1/Q^6$, consistent with the well-known folklore. Its coefficient is expressed in terms of an overlap integral involving the leading and subleading light-cone wave functions of the nucleon, the latter describing the quark state with one unit of orbital angular momentum. We estimate the numerical size of the coefficient and comment on the contribution from the end-point region.

  16. Microstructure and optical absorption of Au-MgF2 nanoparticle cermet films

    Institute of Scientific and Technical Information of China (English)

    Sun Zhao-Qi; Cai Qi; Song Xue-Ping

    2006-01-01

    The microstructure and optical absorption of Au-MgF2 nanoparticle cermet films with different Au contents are studied.The microstructural analysis shows that the films are mainly composed of the amorphous MgF2 matrix with embedded fcc Au nanoparticles with a mean size of 9.8-21.4nm.Spectral analysis suggests that the surface plasma resonance (SPR) absorption peak of Au particles appears at λ=492-537nm.With increasing Au content,absorption peak intensity increases,profile narrows and location redshifts.Theoretical absorption spectra are calculated based on Maxwell-Garnett theory and compared with experimental spectra.

  17. Semiannual and annual variations in the height of the ionospheric F2-peak

    Directory of Open Access Journals (Sweden)

    H. Rishbeth

    Full Text Available Ionosonde data from sixteen stations are used to study the semiannual and annual variations in the height of the ionospheric F2-peak, hmF2. The semiannual variation, which peaks shortly after equinox, has an amplitude of about 8 km at an average level of solar activity (10.7 cm flux = 140 units, both at noon and midnight. The annual variation has an amplitude of about 11 km at northern midlatitudes, peaking in early summer; and is larger at southern stations, where it peaks in late summer. Both annual and semiannual amplitudes increase with increasing solar activity by day, but not at night. The semiannual variation in hmF2 is unrelated to the semiannual variation of the peak electron density NmF2, and is not reproduced by the CTIP and TIME-GCM computational models of the quiet-day thermosphere and ionosphere. The semiannual variation in hmF2 is approximately "isobaric", in that its amplitude corresponds quite well to the semiannual variation in the height of fixed pressure-levels in the thermosphere, as represented by the MSIS empirical model. The annual variation is not "isobaric". The annual mean of hmF2 increases with solar 10.7 cm flux, both by night and by day, on average by about 0.45 km/flux unit, rather smaller than the corresponding increase of height of constant pressure-levels in the MSIS model. The discrepancy may be due to solar-cycle variations of thermospheric winds. Although geomagnetic activity, which affects thermospheric density and temperature and therefore hmF2 also, is greatest at the equinoxes, this seems to account for less than half the semiannual variation of hmF2. The rest may be due to a semiannual variation of tidal and wave energy transmitted to the thermosphere from lower levels in the atmosphere.

    Key words: Atmospheric composition and structure (thermosphere - composition and chemistry - Ionosphere (mid-latitude ionosphere

  18. Mechanisms of plasmid segregation: have multicopy plasmids been overlooked?

    Science.gov (United States)

    Million-Weaver, Samuel; Camps, Manel

    2014-09-01

    Plasmids are self-replicating pieces of DNA typically bearing non-essential genes. Given that plasmids represent a metabolic burden to the host, mechanisms ensuring plasmid transmission to daughter cells are critical for their stable maintenance in the population. Here we review these mechanisms, focusing on two active partition strategies common to low-copy plasmids: par systems type I and type II. Both involve three components: an adaptor protein, a motor protein, and a centromere, which is a sequence area in the plasmid that is recognized by the adaptor protein. The centromere-bound adaptor nucleates polymerization of the motor, leading to filament formation, which can pull plasmids apart (par I) or push them towards opposite poles of the cell (par II). No such active partition mechanisms are known to occur in high copy number plasmids. In this case, vertical transmission is generally considered stochastic, due to the random distribution of plasmids in the cytoplasm. We discuss conceptual and experimental lines of evidence questioning the random distribution model and posit the existence of a mechanism for segregation in high copy number plasmids that moves plasmids to cell poles to facilitate transmission to daughter cells. This mechanism would involve chromosomally-encoded proteins and the plasmid origin of replication. Modulation of this proposed mechanism of segregation could provide new ways to enhance plasmid stability in the context of recombinant gene expression, which is limiting for large-scale protein production and for bioremediation.

  19. Dynamical segregation of galaxies in groups and clusters

    CERN Document Server

    Lares, M; Sánchez, A G

    2004-01-01

    We have performed a systematic analysis of the dynamics of different galaxy populations in galaxy groups from the 2dFGRS. For this purpose we have combined all the groups into a single system, where velocities v and radius r are expressed adimensionally. We have used several methods to compare the distributions of relative velocities of galaxies with respect to the group centre for samples selected according to their spectral type (as defined by Madgwick et al., 2002), bj band luminosity and B-R colour index. We have found strong segregation effects: spectral type I objects show a statistically narrower velocity distribution than that of galaxies with a substantial star formation activity (type II-IV). Similarly, the same behavior is observed for galaxies with colour index B-R>1 compared to galaxies with B-R-19) galaxies show the same segregation. It is not important once the sample is restricted to a given spectral type. These effects are particularly important in the central region (Rp

  20. Unperturbed Schelling Segregation in Two or Three Dimensions

    Science.gov (United States)

    Barmpalias, George; Elwes, Richard; Lewis-Pye, Andrew

    2016-09-01

    Schelling's models of segregation, first described in 1969 (Am Econ Rev 59:488-493, 1969) are among the best known models of self-organising behaviour. Their original purpose was to identify mechanisms of urban racial segregation. But his models form part of a family which arises in statistical mechanics, neural networks, social science, and beyond, where populations of agents interact on networks. Despite extensive study, unperturbed Schelling models have largely resisted rigorous analysis, prior results generally focusing on variants in which noise is introduced into the dynamics, the resulting system being amenable to standard techniques from statistical mechanics or stochastic evolutionary game theory (Young in Individual strategy and social structure: an evolutionary theory of institutions, Princeton University Press, Princeton, 1998). A series of recent papers (Brandt et al. in: Proceedings of the 44th annual ACM symposium on theory of computing (STOC 2012), 2012); Barmpalias et al. in: 55th annual IEEE symposium on foundations of computer science, Philadelphia, 2014, J Stat Phys 158:806-852, 2015), has seen the first rigorous analyses of 1-dimensional unperturbed Schelling models, in an asymptotic framework largely unknown in statistical mechanics. Here we provide the first such analysis of 2- and 3-dimensional unperturbed models, establishing most of the phase diagram, and answering a challenge from Brandt et al. in: Proceedings of the 44th annual ACM symposium on theory of computing (STOC 2012), 2012).

  1. Wilhelm Weinberg’s Early Contribution to Segregation Analysis

    Science.gov (United States)

    Stark, Alan; Seneta, Eugene

    2013-01-01

    Wilhelm Weinberg (1862–1937) is a largely forgotten pioneer of human and medical genetics. His name is linked with that of the English mathematician G. H. Hardy in the Hardy–Weinberg law, pervasive in textbooks on population genetics since it expresses stability over generations of zygote frequencies AA, Aa, aa under random mating. One of Weinberg’s signal contributions, in an article whose centenary we celebrate, was to verify that Mendel’s segregation law still held in the setting of human heredity, contrary to the then-prevailing view of William Bateson (1861–1926), the leading Mendelian geneticist of the time. Specifically, Weinberg verified that the proportion of recessive offspring genotypes aa in human parental crossings Aa × Aa (that is, the segregation ratio for such a setting) was indeed p=14. We focus in a nontechnical way on his procedure, called the simple sib method, and on the heated controversy with Felix Bernstein (1878–1956) in the 1920s and 1930s over work stimulated by Weinberg’s article. PMID:24018765

  2. 46 CFR 151.13-5 - Cargo segregation-tanks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo segregation-tanks. 151.13-5 Section 151.13-5... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... symbols used in lines 1 and 2, in order, under the tank segregation column of Table 151.05....

  3. Residential segregation of socioeconomic variables and health indices in Iran

    Directory of Open Access Journals (Sweden)

    Seyed Saeed Hashemi Nazari

    2013-01-01

    Conclusions: Correlation of segregation of determinants of socioeconomic status with segregation of health indices is an indicator of existence of hot zones of health problems across some provinces. Further studies using multilevel modeling and individual data in health outcomes at individual level and segregation measures at appropriate geographic levels are required to confirm these relations.

  4. Within-School Segregation in an Urban School District

    Science.gov (United States)

    Conger, Dylan

    2005-01-01

    This article examines ethnic segregation, defined as segregation among racial groups as well as between native-born and immigrant students, across elementary school classrooms in New York City. Specifically, the study compares patterns in within-school segregation across ethnic groups, grades, boroughs, and years. Current levels of within-school…

  5. 41 CFR 60-1.8 - Segregated facilities.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Segregated facilities. 60...; Compliance Reports § 60-1.8 Segregated facilities. To comply with its obligations under the Order, a contractor must ensure that facilities provided for employees are provided in such a manner that segregation...

  6. "E Pluribus"... Separation: Deepening Double Segregation for More Students

    Science.gov (United States)

    Orfield, Gary; Kucsera, John; Siegel-Hawley, Genevieve

    2012-01-01

    This report shows segregation has increased dramatically across the country for Latino students, who are attending more intensely segregated and impoverished schools than they have for generations. The segregation increases have been the most dramatic in the West. The typical Latino student in the region attends a school where less than a quarter…

  7. Increased levels of the oxidative stress biomarker 8-iso-prostaglandin F2α in wastewater associated with tobacco use.

    Science.gov (United States)

    Ryu, Yeonsuk; Gracia-Lor, Emma; Bade, Richard; Baz-Lomba, J A; Bramness, Jørgen G; Castiglioni, Sara; Castrignanò, Erika; Causanilles, Ana; Covaci, Adrian; de Voogt, Pim; Hernandez, Felix; Kasprzyk-Hordern, Barbara; Kinyua, Juliet; McCall, Ann-Kathrin; Ort, Christoph; Plósz, Benedek G; Ramin, Pedram; Rousis, Nikolaos I; Reid, Malcolm J; Thomas, Kevin V

    2016-12-15

    Wastewater analysis has been demonstrated to be a complementary approach for assessing the overall patterns of drug use by a population while the full potential of wastewater-based epidemiology has yet to be explored. F2-isoprostanes are a prototype wastewater biomarker to study the cumulative oxidative stress at a community level. In this work, 8-iso-prostaglandin F2α (8-iso-PGF2α) was analysed in raw 24 h-composite wastewater samples collected from 4 Norwegian and 7 other European cities in 2014 and 2015. Using the same samples, biomarkers of alcohol (ethyl sulfate) and tobacco (trans-3'-hydroxycotinine) use were also analysed to investigate any possible correlation between 8-iso-PGF2α and the consumption of the two drugs. The estimated per capita daily loads of 8-iso-PGF2α in the 11 cities ranged between 2.5 and 9.9 mg/day/1000 inhabitants with a population-weighted mean of 4.8 mg/day/1000 inhabitants. There were no temporal trends observed in the levels of 8-iso-PGF2α, however, spatial differences were found at the inter-city level correlating to the degree of urbanisation. The 8-iso-PGF2α mass load was found to be strongly associated with that of trans-3'-hydroxycotinine while it showed no correlation with ethyl sulfate. The present study shows the potential for 8-iso-PGF2α as a wastewater biomarker for the assessment of community public health.

  8. Increased levels of the oxidative stress biomarker 8-iso-prostaglandin F2α in wastewater associated with tobacco use

    Science.gov (United States)

    Ryu, Yeonsuk; Gracia-Lor, Emma; Bade, Richard; Baz-Lomba, J. A.; Bramness, Jørgen G.; Castiglioni, Sara; Castrignanò, Erika; Causanilles, Ana; Covaci, Adrian; de Voogt, Pim; Hernandez, Felix; Kasprzyk-Hordern, Barbara; Kinyua, Juliet; McCall, Ann-Kathrin; Ort, Christoph; Plósz, Benedek G.; Ramin, Pedram; Rousis, Nikolaos I.; Reid, Malcolm J.; Thomas, Kevin V.

    2016-12-01

    Wastewater analysis has been demonstrated to be a complementary approach for assessing the overall patterns of drug use by a population while the full potential of wastewater-based epidemiology has yet to be explored. F2-isoprostanes are a prototype wastewater biomarker to study the cumulative oxidative stress at a community level. In this work, 8-iso-prostaglandin F2α (8-iso-PGF2α) was analysed in raw 24 h-composite wastewater samples collected from 4 Norwegian and 7 other European cities in 2014 and 2015. Using the same samples, biomarkers of alcohol (ethyl sulfate) and tobacco (trans-3‧-hydroxycotinine) use were also analysed to investigate any possible correlation between 8-iso-PGF2α and the consumption of the two drugs. The estimated per capita daily loads of 8-iso-PGF2α in the 11 cities ranged between 2.5 and 9.9 mg/day/1000 inhabitants with a population-weighted mean of 4.8 mg/day/1000 inhabitants. There were no temporal trends observed in the levels of 8-iso-PGF2α, however, spatial differences were found at the inter-city level correlating to the degree of urbanisation. The 8-iso-PGF2α mass load was found to be strongly associated with that of trans-3‧-hydroxycotinine while it showed no correlation with ethyl sulfate. The present study shows the potential for 8-iso-PGF2α as a wastewater biomarker for the assessment of community public health.

  9. Measurement of the $F_{2}^{n}/F_{2}^{p}$ and d/u Ratios in Deep Inelastic Electron Scattering off $^{3}H$ and $^{3}He$

    CERN Document Server

    Petratos, G G; Bissey, F; Gómez, J; Katramatou, A T; Melnitchouk, W; Thomas, A W

    2000-01-01

    We discuss a possible measurement of the ratio of the nucleon structure functions, F2n/F2p, and the ratio of the up to down quark distributions, u/d, at large x, by performing deep inelastic electron scattering from the 3H and 3He mirror nuclei with the 11 GeV upgraded beam of Jefferson Lab. The measurement is expected to be almost free of nuclear effects, which introduce a significant uncertainty in the extraction of these two ratios from deep inelastic scattering off the proton and deuteron. The results are expected to test perturbative and non-perturbative mechanisms of spin-flavor symmetry breaking in the nucleon, and constrain the structure function parameterizations needed for the interpretation of high energy e-p, p-p and p-pbar collider data. The precision of the expected data can also allow for testing competing parameterizations of the nuclear EMC effect and provide valuable constraints on models of its dynamical origin.

  10. PREPARATION OF BaF2 POWDERS BY HYDROTHERMAL METHOD%水热法制备BaF2粉体材料

    Institute of Scientific and Technical Information of China (English)

    李红; 赵星

    2012-01-01

    以销酸钡和氟化铵为原料,以柠檬酸为络合剂,采用水热法合成了BaF2粉体。用扫描电子显微镜(SEM)和X射线衍射仪(XRD)对产物的形貌和结构进行了表征,结果表明反应温度及pH值对产物的形状和尺寸有很大影响,可以通过改变温度和pH值调控产物的形貌。%BaF2 powders were synthesized by hydrothermal methods. For this preparation, Ba(NO3)2 and NH4F as the starting materials and citric acid served as chelator. The morphology and the structure was characterized by scanning electron microscopy (SEM) and X-ray diffraction. The results show that the temperature and pH value of the reaction have significant effects on the particle size and shape. The morphology could be controlled synthesized by the temperature and pH value.

  11. 粉尘螨Der f2变应原的分离纯化及其特征%Purification and Characterization of Der f2 Allergen in Dermatophagoides f arinae

    Institute of Scientific and Technical Information of China (English)

    张鲁雁; 张剑霞; 江世益; 温廷桓; 项黎

    2001-01-01

    Purpose To purify Der f2 allergen from the spent culture medium extract of Dermatophagoides farinae mite(Dff). Methods We purified Der f2 with the aid of Sephadex G-100 gel filtration, DEAE-ion exchange chromatography and polyacrylamide gel electrophoresis, detected the molecular weight of Der f2 using SDS-PAGE method,and analysed the thermostability of Der f2 by heating at 100℃ for 15 min. Results The pure Der f2 was obtained from Dff. The molecular weight of Der f2 was 14 000.The heated-treated Der f2 retained 50% ~83.3% of the activity of the native allergen. Conclusions The properties of purified allergen coincided with the characterization of Der f2.%目的用粉尘螨(Dermatophagoides farnae)代谢培养基浸液(Dff)分离纯化粉尘螨2类变应原(Der f2)。方法采用Sephadex G-100层析、DEAE离子交换层析、PAGE等方法分离纯化Der f2,并对Der f2作 SDS-PAGE测定和热稳定性测定。结果从Dff分离纯化得到较纯的Der f2,经SDS-PAGE测定其相对分子质 量为14 000,并经100℃加热15 min后,仍保留50%~83.3%生物学活性。结论从Dff中分离纯化的变应原, 其物化性质符合Der f2特征。

  12. Finding column depedencies in sparse matrices over $ F_ 2 $ by block Wiedemann

    NARCIS (Netherlands)

    Penninga, O.

    1998-01-01

    Large systems of linear equations over $mathbb{F_2$ with sparse coefficient matrices have to be solved as a part of integer factorization with sieve-based methods such as in the Number Field Sieve algorithm. In this report, we first discuss the Wiedemann algorithm to solve these systems and investig

  13. Magnon dispersion relation and exchange interactions in MnF2

    DEFF Research Database (Denmark)

    Nikotin, O.; Lindgård, Per-Anker; Dietrich, O. W.

    1969-01-01

    The magnon dispersion relation for MnF2 at 4·2 °K has been measured by means of the triple-axis neutron scattering technique along the symmetry lines in the (010) plane of the Brillouin zone. Using an exact dipole model, the three nearest-neighbour exchange constants were found to be J1 = 0·028 ±...

  14. Brillouin Lasing with a CaF_2 Whispering Gallery Mode Resonator

    CERN Document Server

    Grudinin, Ivan S; Maleki, Lute

    2008-01-01

    Stimulated Brillouin scattering with both pump and Stokes beams in resonance with whispering gallery modes of an ultra high Q CaF_2 resonator is demonstrated for the first time. The resonator is pumped with 1064 nm light and has a Brillouin lasing threshold of 3.5 microwatt. Potential applications include optical generation of microwaves and sensitive gyros.

  15. 17 CFR 270.10f-2 - Exercise of warrants or rights received on portfolio securities.

    Science.gov (United States)

    2010-04-01

    ... securities by a registered investment company pursuant to the exercise of warrants or rights to subscribe to... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Exercise of warrants or rights... AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.10f-2...

  16. Effect of CaF2 on Interfacial Phenomena of High Alumina Refractories with Al Alloy

    Science.gov (United States)

    Koshy, Pramod; Gupta, Sushil; Sahajwalla, Veena; Edwards, Phil

    2008-08-01

    An experimental study was conducted to investigate the interfacial phenomena between Al-alloy and industrial grade high alumina refractories containing varying contents of CaF2 at 1250 °C. Interfacial reaction products and phases formed in the heat-treated refractory samples were characterized using electron probe microanalysis (EPMA) and X-ray diffraction (XRD), respectively, while interfacial phenomena including dynamic wetting behavior were analyzed using the sessile drop technique. Refractories containing less than 5 wt pct CaF2 showed good resistance to reactions with the molten alloy, due to the dominance of corundum, and the presence of anorthite at the interface. However, with a further increase in the additive content, a glassy matrix of anorthite with CaF2 was formed. Formation of this phase significantly increased the intensity of reactions resulting in the buildup of an interfacial layer. The study thus revealed the strong catalytic effect of CaF2 on reactions of high alumina refractories with Al-alloy.

  17. Nucleon Structure Function F2 in the Resonance Region and Quark-Hadron Duality

    Institute of Scientific and Technical Information of China (English)

    DONG Yu-Bing; LI Ming-Fei

    2003-01-01

    Based on a simple nonrelativistic constituent quark model, the nucleon structure function F2 in theresonance region is estimated by taking the contributions from low-lying nucleon resonances into account. Calculatedresults are employed to study quark-hardon duality in the nucleon electron scattering process by comparing them to thescaling behavior from the data in deep inelastic scattering region.

  18. eta and eta ' mesons from N-f=2+1+1 twisted mass lattice QCD

    NARCIS (Netherlands)

    Ottnad, Konstantin; Michael, Chris; Reker, Siebren; Urbach, Carsten

    2012-01-01

    We determine mass and mixing angles of eta and eta' states using N-f = 2 + 1 + 1 Wilson twisted mass lattice QCD. We describe how those flavour singlet states need to be treated in this lattice formulation. Results are presented for three values of the lattice spacing, a = 0.061 fm, a = 0.078 fm and

  19. Clock Distributing for BaF2 Readout Electronics at CSNS-WNS

    CERN Document Server

    He, Bing; De-Liang-Zhang,; Wang, Qi; Zhang, Ya-Xi; Qi, Xin-Cheng; Qi-An,

    2016-01-01

    aF2 (Barium Fluoride) detector array is designed for the measurement of (n,{\\gamma}) cross section precisely at CSNS-WNS (white neutron source at China Spallation Neutron Source). It is a 4{\\pi}solid angle-shaped detector array consisting of 92 BaF2 crystal elements. To discriminate signals from BaF2 detector, pulse shape discrimination methodology is used, which is supported by waveform digitization technique. There are total 92 channels for digitizing. The precision and synchronization of clock distribution restricts the performance of waveform digitizing. In this paper, the clock prototype for BaF2 readout electronics at CSNS-WNS is introduced. It is based on PXIe platform and has a twin-stage tree topology. In the first stage, clock is distributed from the tree root to each PXIe crate synchronously through coaxial cable over long distance, while in the second stage, clock is further distributed to each electronic module through PXIe dedicated differential star bus. With the help of this topology, each tre...

  20. Response of MEDEA BaF 2 detectors to 20-280 MeV photons

    Science.gov (United States)

    Bellia, G.; Alba, R.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Maiolino, C.; Migneco, E.; Piattelli, P.; Sapienza, P.; Frascaria, N.; Lhenry, I.; Roynette, J. C.; Suomijärvi, T.; Alamanos, N.; Auger, F.; Gillibert, A.; Pierroutsakou, D.; Sida, J. L.; Silveira Gomes, P. R.

    1993-05-01

    The response function of MEDEA BaF 2 crystals to high energy photons, up to 280 MeV, has been studied using monochromatic γ-rays from the in flight annihilation of positron beams. The experimental response functions are compared to the results of Monte Carlo simulations based on the EGS3 code and parametrized over the whole investigated energy range.

  1. Ground state charmed meson spectra for N_f=2+1+1

    CERN Document Server

    Rae, T D

    2015-01-01

    We present a preliminary study of the charmed meson spectra using the electrically neutral subset of the new Budapest-Marseille-Wuppertal N_f=2+1+1 gauge configurations that utilise the 3-HEX smeared clover action. The analysis is performed with a focus on the hyperfine splitting.

  2. Relationship between Kinematics, F2 Slope and Speech Intelligibility in Dysarthria Due to Cerebral Palsy

    Science.gov (United States)

    Rong, Panying; Loucks, Torrey; Kim, Heejin; Hasegawa-Johnson, Mark

    2012-01-01

    A multimodal approach combining acoustics, intelligibility ratings, articulography and surface electromyography was used to examine the characteristics of dysarthria due to cerebral palsy (CP). CV syllables were studied by obtaining the slope of F2 transition during the diphthong, tongue-jaw kinematics during the release of the onset consonant,…

  3. FRAMES-2.0 Software System: Frames 2.0 Pest Integration (F2PEST)

    Energy Technology Data Exchange (ETDEWEB)

    Castleton, Karl J.; Meyer, Philip D.

    2009-06-17

    The implementation of the FRAMES 2.0 F2PEST module is described, including requirements, design, and specifications of the software. This module integrates the PEST parameter estimation software within the FRAMES 2.0 environmental modeling framework. A test case is presented.

  4. Extreme 13C depletion of CCl2F2 in firn air samples from NEEM, Greenland

    NARCIS (Netherlands)

    Zuiderweg, A.T.; Holzinger, R.; Röckmann, T.

    2012-01-01

    A series of 12 high volume air samples collected from the S2 firn core during the North Greenland Eemian Ice Drilling (NEEM) 2009 campaign have been measured for mixing ratio and stable carbon isotope composition of the chlorofluorocarbon CFC- 12 (CCl2F2). While the mixing ratio measurements compare

  5. In-Situ Conductivity Measurement of BaF2 under High Pressure and High Temperature

    Institute of Scientific and Technical Information of China (English)

    HAO Ai-Min; LI Xiao-Dong; LIU Jing; GAO Chun-Xiao; LI Ming; HE Chun-Yuan; HUANG Xiao-Wei; ZHANG Dong-Mei; YU Cui-Ling; ZOU Guang-Tian; LI Yan-Chun

    2006-01-01

    @@ We perform the in-situ conductivity measurement on BaF2 at high pressure using a microcircuit fabricated on a diamond anvil cell. The results show that BaF2 initially exhibits the electrical property of an insulator at pressure below 25 Gpa, it transforms to a wide energy gap semiconductor at pressure from 25 to 30 Gpa, and the conductivity increases gradually with increasing pressure from 30 Gpa. However, the metallization predicted by theoretical calculation at 30-33 Gpa cannot be observed. In addition, we measure the temperature dependence of the conductivity at several pressures and obtain the relationship between the energy gap and pressure. Based on the experimental data, it is predicted that BaF2 would transform to a metal at about 87 Gpa and ambient temperature. The conductivity of BaF2 reaches the order of 10-3Ω-1 cm-1 at 37 Gpa and 2400 K, the superionic conduction is not observed during the experiments, indicating the application of pressure elevates greatly the transition temperature of the superionic conduction.

  6. The Rho Resonance from $N_f=2+1+1$ Twisted Mass Lattice QCD

    CERN Document Server

    Helmes, C; Knippschild, B; Liu, L; Urbach, C; Werner, M; Wang, Z

    2015-01-01

    We present first results on the $\\rho$ resonance parameters obtained with $N_f=2+1+1$ Wilson twisted mass fermions at maximal twist. Using ensembles of the ETM collaboration, we provide results for two values of the lattice spacing and a range of pion mass values.

  7. Measurement of the Proton Structure Function $F_{2}$ at Very Low $Q^{2}$ at HERA

    CERN Document Server

    Breitweg, J; Derrick, Malcolm; Krakauer, D A; Magill, S; Musgrave, B; Pellegrino, A; Repond, J; Stanek, R; Yoshida, R; Mattingly, M C K; Abbiendi, G; Anselmo, F; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Cara Romeo, G; Castellini, G; Cifarelli, Luisa; Cindolo, F; Contin, A; Coppola, N; Corradi, M; De Pasquale, S; Giusti, P; Iacobucci, G; Laurenti, G; Levi, G; Margotti, A; Massam, Thomas; Nania, R; Palmonari, F; Pesci, A; Polini, A; Sartorelli, G; Zamora-Garcia, Yu E; Zichichi, A; Amelung, C; Bornheim, A; Brock, I; Coboken, K; Crittenden, James Arthur; Deffner, R; Hartmann, H; Heinloth, K; Hilger, E; Irrgang, P; Jakob, H P; Kappes, A; Katz, U F; Kerger, R; Paul, E; Schnurbusch, H; Stifutkin, A; Tandler, J; Voss, K C; Weber, A; Wieber, H; Bailey, D S; Barret, O; Brook, N H; Foster, B; Heath, G P; Heath, H F; McFall, J D; Piccioni, D; Rodrigues, E; Scott, J; Tapper, R J; Capua, M; Mastroberardino, A; Schioppa, M; Susinno, G; Jeoung, H Y; Kim, J Y; Lee, J H; Lim, I T; Ma, K J; Pac, M Y; Caldwell, A; Liu, W; Liu, X; Mellado, B; Paganis, S; Sampson, S; Schmidke, W B; Sciulli, F; Chwastowski, J; Eskreys, Andrzej; Figiel, J; Klimek, K H; Olkiewicz, K; Piotrzkowski, K; Przybycien, M B; Stopa, P; Zawiejski, L; Bednarek, B; Jelen, K; Kisielewska, D; Kowal, A M; Kowalski, T; Rulikowska-Zarebska, E; Suszycki, L; Szuba, D; Kotanski, Andrzej; Bauerdick, L A T; Behrens, U; Bienlein, J K; Burgard, C; Dannheim, D; Desler, K; Drews, G; Fox-Murphy, A; Fricke, U; Göbel, F; Göttlicher, P; Graciani, R; Haas, T; Hain, W; Hartner, G F; Hasell, D; Hebbel, K; Johnson, K F; Kasemann, M; Koch, W; Kötz, U; Kowalski, H; Lindemann, L; Löhr, B; Martínez, M; Milite, M; Monteiro, T; Moritz, M; Notz, D; Pelucchi, F; Petrucci, M C; Rohde, M; Saull, P R B; Savin, A A; Schneekloth, U; Selonke, F; Sievers, M; Stonjek, S; Tassi, E; Wolf, G; Wollmer, U; Youngman, C; Zeuner, W; Coldewey, C; López-Duran-Viani, A; Meyer, A; Schlenstedt, S; Straub, P B; Barbagli, G; Gallo, E; Pelfer, P G; Maccarrone, G D; Votano, L; Bamberger, Andreas; Benen, A; Eisenhardt, S; Markun, P; Raach, H; Wölfle, S; Bussey, Peter J; Bell, M; Doyle, A T; Lee, S W; Lupi, A; MacDonald, N; McCance, G J; Saxon, D H; Sinclair, L E; Skillicorn, Ian O; Waugh, R; Bohnet, I; Gendner, N; Holm, U; Meyer-Larsen, A; Salehi, H; Wick, K; Garfagnini, A; Gialas, I; Gladilin, L K; Kcira, D; Klanner, Robert; Lohrmann, E; Poelz, G; Zetsche, F; Goncalo, R; Long, K R; Miller, D B; Tapper, A D; Walker, R; Mallik, U; Cloth, P; Filges, D; Ishii, T; Kuze, M; Nagano, K; Tokushuku, K; Yamada, S; Yamazaki, Y; Ahn, S H; Lee, S B; Park, S K; Lim, H; Park, I H; Son, D; Barreiro, F; García, G; Glasman, C; González, O; Labarga, L; Del Peso, J; Redondo, I; Terron, J; Barbi, M S; Corriveau, F; Hanna, D S; Ochs, A; Padhi, S; Riveline, M; Stairs, D G; Wing, M; Tsurugai, T; Antonov, A; Bashkirov, V; Danilov, M V; Dolgoshein, B A; Gladkov, D; Sosnovtsev, V V; Suchkov, S; Dementev, R K; Ermolov, P F; Golubkov, Yu A; Katkov, I I; Khein, L A; Korotkova, N A; Korzhavina, I A; Kuzmin, V A; Lukina, O Yu; Proskuryakov, A S; Shcheglova, L M; Solomin, A N; Vlasov, N N; Zotkin, S A; Bokel, C; Botje, M; Brümmer, N; Engelen, J; Grijpink, S; Koffeman, E; Kooijman, P M; Schagen, S; Van Sighem, A; Tiecke, H G; Tuning, N; Velthuis, J J; Vossebeld, Joost Herman; Wiggers, L; De Wolf, E; Acosta, D; Bylsma, B; Durkin, L S; Gilmore, J; Ginsburg, C M; Kim, C L; Ling, T Y; Boogert, S; Cooper-Sarkar, A M; Devenish, R C E; Grosse-Knetter, J; Matsushita, T; Quadt, A; Ruske, O; Sutton, M R; Walczak, R; Bertolin, A; Brugnera, R; Carlin, R; Dal Corso, F; Dosselli, U; Dusini, S; Limentani, S; Morandin, M; Posocco, M; Stanco, L; Stroili, R; Turcato, M; Voci, C; Adamczyk, L; Iannotti, L; Oh, B Y; Okrasinski, J R; Toothacker, W S; Whitmore, J J; Iga, Y; D'Agostini, Giulio; Marini, G; Nigro, A; Cormack, C; Hart, J C; McCubbin, N A; Shah, T P; Epperson, D E; Heusch, C A; Sadrozinski, H F W; Seiden, A; Wichmann, R; Williams, D C; Pavel, N; Abramowicz, H; Dagan, S; Kananov, S; Kreisel, A; Levy, A; Abe, T; Fusayasu, T; Umemori, K; Yamashita, T; Hamatsu, R; Hirose, T; Inuzuka, M; Kitamura, S; Nishimura, T; Arneodo, M; Cartiglia, N; Cirio, R; Costa, M; Ferrero, M I; Maselli, S; Monaco, V; Peroni, C; Ruspa, M; Sacchi, R; Solano, A; Staiano, A; Dardo, M; Bailey, D C; Fagerstroem, C P; Galea, R; Koop, T; Levman, G M; Martin, J F; Orr, R S; Polenz, S; Sabetfakhri, A; Simmons, D; Butterworth, J M; Catterall, C D; Hayes, M E; Heaphy, E A; Jones, T W; Lane, J B; West, B J; Ciborowski, J; Ciesielski, R; Grzelak, G; Nowak, R J; Pawlak, J M; Pawlak, R; Smalska, B; Tymieniecka, T; Wróblewski, A K; Zakrzewski, J A; Zarnecki, A F; Adamus, M; Gadaj, T; Deppe, O; Eisenberg, Y; Hochman, D; Karshon, U; Badgett, W F; Chapin, D; Cross, R; Foudas, C; Mattingly, S E K; Reeder, D D; Smith, W H; Vaiciulis, A W; Wildschek, T; Wodarczyk, M; Deshpande, A A; Dhawan, S K; Hughes, V W; Bhadra, S; Cole, J E; Frisken, W R; Hall-Wilton, R; Khakzad, M; Menary, S R

    2000-01-01

    A measurement of the proton structure function F_2(x,Q^2) is presented in the kinematic range 0.045 GeV^2 < Q^2 < 0.65 GeV^2 and 6*10^{-7} < x < 1*10^{-3}. The results were obtained using a data sample corresponding to an integrated luminosity of 3.9pb^-1 in e^+p reactions recorded with the ZEUS detector at HERA. Information from a silicon-strip tracking detector, installed in front of the small electromagnetic calorimeter used to measure the energy of the final-state positron at small scattering angles, together with an enhanced simulation of the hadronic final state, has permitted the extension of the kinematic range beyond that of previous measurements. The uncertainties in F_2 are typically less than 4%. At the low Q^2 values of the present measurement, the rise of F_2 at low x is slower than observed in HERA data at higher Q^2 and can be described by Regge theory with a constant logarithmic slope. The dependence of F_2 on Q^2 is stronger than at higher Q^2 values, approaching, at the lowest Q...

  8. A status report of the QCDSF N{sub f}=2+1 project

    Energy Technology Data Exchange (ETDEWEB)

    Goeckeler, Meinulf [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, Roger [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Yoshifumi [DESY, Zeuthen (DE). John von Neumann Institute NIC] (and others)

    2007-12-20

    We report about on-going simulations of N{sub f}=2+1 lattice QCD. We use a tadpole improved Symanzik gauge action and stout link smeared Wilson fermions with a clover term. We employ the Hasenbusch trick for the degenerate u- and d-quarks, and the RHMC algorithm for the simulation of the strange quark. (orig.)

  9. Time scale of entropic segregation of flexible polymers in confinement: Implications for chromosome segregation in filamentous bacteria

    OpenAIRE

    Arnold, Axel; Jun, Suckjoon

    2007-01-01

    We report molecular dynamics simulations of the segregation of two overlapping chains in cylindrical confinement. We find that the entropic repulsion between the chains can be sufficiently strong to cause segregation on a time scale that is short compared to the one for diffusion. This result implies that entropic driving forces are sufficiently strong to cause rapid bacterial chromosome segregation.

  10. Time scale of entropic segregation of flexible polymers in confinement: Implications for chromosome segregation in filamentous bacteria

    Science.gov (United States)

    Arnold, Axel; Jun, Suckjoon

    2007-09-01

    We report molecular dynamics simulations of the segregation of two overlapping chains in cylindrical confinement. We find that the entropic repulsion between chains can be sufficiently strong to cause segregation on a time scale that is short compared to the one for diffusion. This result implies that entropic driving forces are sufficiently strong to cause rapid bacterial chromosome segregation.

  11. From Schelling to Schools : A comparison of a model of residential segregation with a model of school segregation

    NARCIS (Netherlands)

    Stoica, Victor; Flache, Andreas

    2014-01-01

    We address theoretically whether and under what conditions Schelling's celebrated result of 'self-organized' unintended residential segregation may also apply to school segregation. We propose here a computational model of school segregation that is aligned with a corresponding Schelling-type model

  12. Phase diagram of a Schelling segregation model

    Science.gov (United States)

    Gauvin, L.; Vannimenus, J.; Nadal, J.-P.

    2009-07-01

    The collective behavior in a variant of Schelling’s segregation model is characterized with methods borrowed from statistical physics, in a context where their relevance was not conspicuous. A measure of segregation based on cluster geometry is defined and several quantities analogous to those used to describe physical lattice models at equilibrium are introduced. This physical approach allows to distinguish quantitatively several regimes and to characterize the transitions between them, leading to the building of a phase diagram. Some of the transitions evoke empirical sudden ethnic turnovers. We also establish links with ‘spin-1’ models in physics. Our approach provides generic tools to analyze the dynamics of other socio-economic systems.

  13. Sister chromatid segregation in meiosis II

    Science.gov (United States)

    Wassmann, Katja

    2013-01-01

    Meiotic divisions (meiosis I and II) are specialized cell divisions to generate haploid gametes. The first meiotic division with the separation of chromosomes is named reductional division. The second division, which takes place immediately after meiosis I without intervening S-phase, is equational, with the separation of sister chromatids, similar to mitosis. This meiotic segregation pattern requires the two-step removal of the cohesin complex holding sister chromatids together: cohesin is removed from chromosome arms that have been subjected to homologous recombination in meiosis I and from the centromere region in meiosis II. Cohesin in the centromere region is protected from removal in meiosis I, but this protection has to be removed—deprotected”—for sister chromatid segregation in meiosis II. Whereas the mechanisms of cohesin protection are quite well understood, the mechanisms of deprotection have been largely unknown until recently. In this review I summarize our current knowledge on cohesin deprotection. PMID:23574717

  14. Organization and segregation of bacterial chromosomes.

    Science.gov (United States)

    Wang, Xindan; Montero Llopis, Paula; Rudner, David Z

    2013-03-01

    The bacterial chromosome must be compacted more than 1,000-fold to fit into the compartment in which it resides. How it is condensed, organized and ultimately segregated has been a puzzle for over half a century. Recent advances in live-cell imaging and genome-scale analyses have led to new insights into these problems. We argue that the key feature of compaction is the orderly folding of DNA along adjacent segments and that this organization provides easy and efficient access for protein-DNA transactions and has a central role in driving segregation. Similar principles and common proteins are used in eukaryotes to condense and to resolve sister chromatids at metaphase.

  15. Socio-Spatial Segregations in Social Media

    Directory of Open Access Journals (Sweden)

    Murat SEIFY

    2016-12-01

    Full Text Available In conjunction with developments in communication technologies, life spaces of people also change and develop. What constitutes the most important building block of these new life spaces are digital communication resources. Digital communication resources form new spaces in social media by manipulating identities and cultures. These new spaces create socio-spatial segregations, whether consciously or unconsciously. Especially in recent years, grouping is observed intensely in social media and from time to time these groups play an important role in mass actions. In this study, closed and secret groups formed in social media were examined, with qualitative and quantitative research methods. Within this context, through in-depth interviews with group admins and survey study with group members, socio-spatial segregation in social media and grouping processes in social media were examined.

  16. Phase Segregation in Polystyrene?Polylactide Blends

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Bonnie; Hitchcock, Adam; Brash, John; Scholl, Andreas; Doran, Andrew

    2010-06-09

    Spun-cast films of polystyrene (PS) blended with polylactide (PLA) were visualized and characterized using atomic force microscopy (AFM) and synchrotron-based X-ray photoemission electron microscopy (X-PEEM). The composition of the two polymers in these systems was determined by quantitative chemical analysis of near-edge X-ray absorption signals recorded with X-PEEM. The surface morphology depends on the ratio of the two components, the total polymer concentration, and the temperature of vacuum annealing. For most of the blends examined, PS is the continuous phase with PLA existing in discrete domains or segregated to the air?polymer interface. Phase segregation was improved with further annealing. A phase inversion occurred when films of a 40:60 PS:PLA blend (0.7 wt percent loading) were annealed above the glass transition temperature (Tg) of PLA.

  17. Granular segregation driven by particle interactions.

    Science.gov (United States)

    Lozano, C; Zuriguel, I; Garcimartín, A; Mullin, T

    2015-05-01

    We report the results of an experimental study of particle-particle interactions in a horizontally shaken granular layer that undergoes a second order phase transition from a binary gas to a segregation liquid as the packing fraction C is increased. By focusing on the behavior of individual particles, the effect of C is studied on (1) the process of cluster formation, (2) cluster dynamics, and (3) cluster destruction. The outcomes indicate that the segregation is driven by two mechanisms: attraction between particles with the same properties and random motion with a characteristic length that is inversely proportional to C. All clusters investigated are found to be transient and the probability distribution functions of the separation times display a power law tail, indicating that the splitting probability decreases with time.

  18. Protein-protein docking with F(2Dock 2.0 and GB-rerank.

    Directory of Open Access Journals (Sweden)

    Rezaul Chowdhury

    Full Text Available MOTIVATION: Computational simulation of protein-protein docking can expedite the process of molecular modeling and drug discovery. This paper reports on our new F(2 Dock protocol which improves the state of the art in initial stage rigid body exhaustive docking search, scoring and ranking by introducing improvements in the shape-complementarity and electrostatics affinity functions, a new knowledge-based interface propensity term with FFT formulation, a set of novel knowledge-based filters and finally a solvation energy (GBSA based reranking technique. Our algorithms are based on highly efficient data structures including the dynamic packing grids and octrees which significantly speed up the computations and also provide guaranteed bounds on approximation error. RESULTS: The improved affinity functions show superior performance compared to their traditional counterparts in finding correct docking poses at higher ranks. We found that the new filters and the GBSA based reranking individually and in combination significantly improve the accuracy of docking predictions with only minor increase in computation time. We compared F(2 Dock 2.0 with ZDock 3.0.2 and found improvements over it, specifically among 176 complexes in ZLab Benchmark 4.0, F(2 Dock 2.0 finds a near-native solution as the top prediction for 22 complexes; where ZDock 3.0.2 does so for 13 complexes. F(2 Dock 2.0 finds a near-native solution within the top 1000 predictions for 106 complexes as opposed to 104 complexes for ZDock 3.0.2. However, there are 17 and 15 complexes where F(2 Dock 2.0 finds a solution but ZDock 3.0.2 does not and vice versa; which indicates that the two docking protocols can also complement each other. AVAILABILITY: The docking protocol has been implemented as a server with a graphical client (TexMol which allows the user to manage multiple docking jobs, and visualize the docked poses and interfaces. Both the server and client are available for download. Server

  19. Protein-protein docking with F(2)Dock 2.0 and GB-rerank.

    Science.gov (United States)

    Chowdhury, Rezaul; Rasheed, Muhibur; Keidel, Donald; Moussalem, Maysam; Olson, Arthur; Sanner, Michel; Bajaj, Chandrajit

    2013-01-01

    Computational simulation of protein-protein docking can expedite the process of molecular modeling and drug discovery. This paper reports on our new F(2) Dock protocol which improves the state of the art in initial stage rigid body exhaustive docking search, scoring and ranking by introducing improvements in the shape-complementarity and electrostatics affinity functions, a new knowledge-based interface propensity term with FFT formulation, a set of novel knowledge-based filters and finally a solvation energy (GBSA) based reranking technique. Our algorithms are based on highly efficient data structures including the dynamic packing grids and octrees which significantly speed up the computations and also provide guaranteed bounds on approximation error. The improved affinity functions show superior performance compared to their traditional counterparts in finding correct docking poses at higher ranks. We found that the new filters and the GBSA based reranking individually and in combination significantly improve the accuracy of docking predictions with only minor increase in computation time. We compared F(2) Dock 2.0 with ZDock 3.0.2 and found improvements over it, specifically among 176 complexes in ZLab Benchmark 4.0, F(2) Dock 2.0 finds a near-native solution as the top prediction for 22 complexes; where ZDock 3.0.2 does so for 13 complexes. F(2) Dock 2.0 finds a near-native solution within the top 1000 predictions for 106 complexes as opposed to 104 complexes for ZDock 3.0.2. However, there are 17 and 15 complexes where F(2) Dock 2.0 finds a solution but ZDock 3.0.2 does not and vice versa; which indicates that the two docking protocols can also complement each other. The docking protocol has been implemented as a server with a graphical client (TexMol) which allows the user to manage multiple docking jobs, and visualize the docked poses and interfaces. Both the server and client are available for download. Server: http://www.cs.utexas.edu/~bajaj/cvc/software/f

  20. Protein-Protein Docking with F2Dock 2.0 and GB-Rerank

    Science.gov (United States)

    Chowdhury, Rezaul; Rasheed, Muhibur; Keidel, Donald; Moussalem, Maysam; Olson, Arthur; Sanner, Michel; Bajaj, Chandrajit

    2013-01-01

    Motivation Computational simulation of protein-protein docking can expedite the process of molecular modeling and drug discovery. This paper reports on our new F2 Dock protocol which improves the state of the art in initial stage rigid body exhaustive docking search, scoring and ranking by introducing improvements in the shape-complementarity and electrostatics affinity functions, a new knowledge-based interface propensity term with FFT formulation, a set of novel knowledge-based filters and finally a solvation energy (GBSA) based reranking technique. Our algorithms are based on highly efficient data structures including the dynamic packing grids and octrees which significantly speed up the computations and also provide guaranteed bounds on approximation error. Results The improved affinity functions show superior performance compared to their traditional counterparts in finding correct docking poses at higher ranks. We found that the new filters and the GBSA based reranking individually and in combination significantly improve the accuracy of docking predictions with only minor increase in computation time. We compared F2 Dock 2.0 with ZDock 3.0.2 and found improvements over it, specifically among 176 complexes in ZLab Benchmark 4.0, F2 Dock 2.0 finds a near-native solution as the top prediction for 22 complexes; where ZDock 3.0.2 does so for 13 complexes. F2 Dock 2.0 finds a near-native solution within the top 1000 predictions for 106 complexes as opposed to 104 complexes for ZDock 3.0.2. However, there are 17 and 15 complexes where F2 Dock 2.0 finds a solution but ZDock 3.0.2 does not and vice versa; which indicates that the two docking protocols can also complement each other. Availability The docking protocol has been implemented as a server with a graphical client (TexMol) which allows the user to manage multiple docking jobs, and visualize the docked poses and interfaces. Both the server and client are available for download. Server: http://www.cs.utexas.edu/~bajaj/cvc/software/f

  1. Chromosomal organization and segregation in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Isabelle Vallet-Gely

    2013-05-01

    Full Text Available The study of chromosomal organization and segregation in a handful of bacteria has revealed surprising variety in the mechanisms mediating such fundamental processes. In this study, we further emphasized this diversity by revealing an original organization of the Pseudomonas aeruginosa chromosome. We analyzed the localization of 20 chromosomal markers and several components of the replication machinery in this important opportunistic γ-proteobacteria pathogen. This technique allowed us to show that the 6.3 Mb unique circular chromosome of P. aeruginosa is globally oriented from the old pole of the cell to the division plane/new pole along the oriC-dif axis. The replication machinery is positioned at mid-cell, and the chromosomal loci from oriC to dif are moved sequentially to mid-cell prior to replication. The two chromosomal copies are subsequently segregated at their final subcellular destination in the two halves of the cell. We identified two regions in which markers localize at similar positions, suggesting a bias in the distribution of chromosomal regions in the cell. The first region encompasses 1.4 Mb surrounding oriC, where loci are positioned around the 0.2/0.8 relative cell length upon segregation. The second region contains at least 800 kb surrounding dif, where loci show an extensive colocalization step following replication. We also showed that disrupting the ParABS system is very detrimental in P. aeruginosa. Possible mechanisms responsible for the coordinated chromosomal segregation process and for the presence of large distinctive regions are discussed.

  2. Segregation effects in DEEP2 galaxy groups

    Science.gov (United States)

    Nascimento, R. S.; Ribeiro, A. L. B.; Lopes, P. A. A.

    2016-09-01

    We investigate segregation phenomena in galaxy groups in the range of 0.2 low(z ≤ 0.6) and high (z > 0.6) redshift groups. Assuming that the color index (U - B)0 can be used as a proxy for the galaxy type, we found that the fraction of blue (star-forming) objects is higher in the high-z sample, with blue objects being dominant at MB > -19.5 for both samples, and red objects being dominant at MB low-z sample. Also, the radial variation of the red fraction indicates that there are more red objects with R low-z sample than in the high-z sample. Our analysis indicates statistical evidence of kinematic segregation, at the 99% c.l., for the low-z sample: redder and brighter galaxies present lower velocity dispersions than bluer and fainter ones. We also find a weaker evidence for spatial segregation between red and blue objects, at the 70% c.l. The analysis of the high-z sample reveals a different result: red and blue galaxies have velocity dispersion distributions not statistically distinct, although redder objects are more concentrated than the bluer ones at the 95% c.l. From the comparison of blue/red and bright/faint fractions, and considering the approximate lookback timescale between the two samples (˜3 Gyr), our results are consistent with a scenario where bright red galaxies had time to reach energy equipartition, while faint blue/red galaxies in the outskirts infall to the inner parts of the groups, thus reducing spatial segregation from z ˜ 0.8 to z ˜ 0.4.

  3. Plasmid and chromosome segregation in prokaryotes

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Bugge Jensen, Rasmus; Gerdes, Kenn

    2000-01-01

    Recent major advances in the understanding of prokaryotic DNA segregation have been achieved by using fluorescence microscopy to visualize the localization of cellular components. Plasmids and bacterial chromosomes are partitioned in a highly dynamic fashion, suggesting the presence of a mitotic......-like apparatus in prokaryotes. The identification of chromosomal homologues of the well-characterized plasmid partitioning genes indicates that there could be a general mechanism of bacterial DNA partitioning. Udgivelsesdato: July 1...

  4. Effects of container geometry on granular segregation pattern

    Institute of Scientific and Technical Information of China (English)

    Hu Mao-Bin; Kong Xiang-Zhao; Wu Qing-Song; Wu Yong-Hong

    2005-01-01

    In a set of vibrating quasi-two-dimensional containers with the right-hand sidewall bent inward, three new segregation patterns have been identified experimentally including a Two-Side segregation Pattern, a Left-hand Side segregation Pattern and a pattern where big particles aggregate to the upper left part of the container. In a container with small bending degree, either the two-side segregation pattern or the left-hand side segregation pattern is stable, which is determined by the initial distribution of particles.

  5. Comparison of On-line and F2F Education Methods in Teaching Computer Programming

    Directory of Open Access Journals (Sweden)

    Sevinç Gülseçen

    2013-08-01

    Full Text Available lthough online education provides opportunities to people who traditionally do not have access to universities, there is a need for more empirical studies to gain better understanding on how to deliver quality online education, especially when the subject of the course is related with IT. Learning to program is a complicated process. This study aims to find out the difference between students’ performance in online and face-to-face (F2F settings during a computer programming in the fall semester of the year 2010. The study was conducted at the Department of Mathematics, Faculty of Science, Istanbul University. This online course is one of the required courses for students majoring in Mathematics. It is delivered in a learning management system developed in house through a project funded by Istanbul University. The goal is to introduce students with structured programming using the programming language C. Two topics -“Functions in C Programming” and “Loops in C Programming” - were presented to students online and F2F. The total of 62 students formed two groups: the online and F2F groups. The content analysis statistical technique is used, as well as a questionnaire consisting of open-ended questions, which performed as a data collection tool to find out the views of the students in context to the process. While some results concluded that the performance of online students was satisfactory, but that their aggregate final grade was significantly lower than that of students who took an equivalent F2F class, others arrived at a conclusion reporting that there were no significant differences in overall outcomes. In case of making transition from F2F to online mode of teaching, prepossession about a new way of teaching is always an important barrier in students’ perceptions. One of the further researches is investigation of strategies for incorporating blended learning opportunities in programming courses.

  6. ITO-MgF2 Film Development for PowerSphere Polymer Surface Protection

    Science.gov (United States)

    Hambourger, Paul D.; Kerslake, Thomas W.; Waters, Deborah L.

    2004-01-01

    Multi-kilogram class microsatellites with a PowerSphere electric power system are attractive for fulfilling a variety of potential NASA missions. However, PowerSphere polymer surfaces must be coated with a film that has suitable electrical sheet resistivity for electrostatic discharge control, be resistant to atomic oxygen attack, be transparent to ultraviolet light for composite structure curing and resist ultraviolet light induced darkening for efficient photovoltaic cell operation. In addition, the film must be tolerant of polymer layer folding associated with launch stowage of PowerSphere inflatable structures. An excellent film material candidate to meet these requirements is co-sputtered, indium oxide (In2O3) - tin oxide (SnO2), known as 'ITO', and magnesium fluoride (MgF2). While basic ITO-MgF2 film properties have been the subject of research over the last decade, further research is required in the areas of film durability for space-inflatable applications and precise film property control for large scale commercial production. In this paper, the authors present film durability results for a folded polymer substrate and film resistance to vacuum UV darkening. The authors discuss methods and results in the area of film sheet resistivity measurement and active control, particularly dual-channel, plasma emission line measurement of ITO and MgF2 plasma sources. ITO-MgF2 film polymer coupon preparation is described as well as film deposition equipment, procedures and film characterization. Durability testing methods are also described. The pre- and post-test condition of the films is assessed microscopically and electrically. Results show that an approx. 500A ITO-18vol% MgF2 film is a promising candidate to protect PowerSphere polymer surfaces for Earth orbit missions. Preliminary data also indicate that in situ film measurement methods are promising for active film resistivity control in future large scale production. Future film research plans are also

  7. Clock distribution for BaF2 readout electronics at CSNS-WNS

    Science.gov (United States)

    He, Bing; Cao, Ping; Zhang, De-Liang; Wang, Qi; Zhang, Ya-Xi; Qi, Xin-Cheng; An, Qi

    2017-01-01

    A BaF2 (Barium Fluoride) detector array is designed to precisely measure the (n, γ) cross section at the CSNS-WNS (white neutron source at China Spallation Neutron Source). It is a 4π solid angle-shaped detector array consisting of 92 BaF2 crystal elements. To discriminate signals from the BaF2 detector, a pulse shape discrimination method is used, supported by a waveform digitization technique. There are 92 channels for digitizing. The precision and synchronization of clock distribution restricts the performance of waveform digitizing. In this paper, a clock prototype for the BaF2 readout electronics at CSNS-WNS is introduced. It is based on the PXIe platform and has a twin-stage tree topology. In the first stage, clock is synchronously distributed from the tree root to each PXIe crate through a coaxial cable over a long distance, while in the second stage, the clock is further distributed to each electronic module through a PXIe dedicated differential star bus. With the help of this topology, each tree node can fan out up to 20 clocks with 3U size. Test results show the clock jitter is less than 20 ps, which meets the requirements of the BaF2 readout electronics. Besides, this clock system has the advantages of high density, simplicity, scalability and cost saving, so it can be useful for other clock distribution applications. Supported by National Research and Development plan (2016 YFA0401602) NSAF (U1530111) and National Natural Science Foundation of China (11005107)

  8. F2 region response to geomagnetic disturbances across Indian latitudes: O(1S) dayglow emission

    Science.gov (United States)

    Upadhayaya, A. K.; Gupta, Sumedha; Brahmanandam, P. S.

    2016-03-01

    The morphology of ionospheric storms has been investigated across equatorial and low latitudes of Indian region. The deviation in F2 region characteristic parameters (foF2 and h'F) along with modeled green line dayglow emission intensities is examined at equatorial station Thiruvananthapuram (8.5°N, 76.8°E, 0.63°S geomagnetic latitude) and low-latitude station Delhi (28.6°N, 77.2°E,19.2°N geomagnetic latitude) during five geomagnetic storm events. Both positive and negative phases have been noticed in this study. The positive storm phase over equatorial station is found to be more frequent, while the drop in ionization in most of the cases was observed at low-latitude station. It is concluded that the reaction as seen at different ionospheric stations may be quite different during the same storm depending on both the geographic and geomagnetic coordinates of the station, storm intensity, and the storm onset time. Modulation in the F2 layer critical frequency at low and equatorial stations during geomagnetic disturbance of 20-23 November 2003 was caused by the storm-induced changes in O/N2. It is also found that International Reference Ionosphere 2012 model predicts the F2 layer characteristic (foF2 and h'F) parameters at both the low and equatorial stations during disturbed days quite reasonably. A simulative approach in GLOW model developed by Solomon is further used to estimate the changes in the volume emission rate of green line dayglow emission under quiet and strong geomagnetic conditions. It is found that the O(1S) dayglow thermospheric emission peak responds to varying geomagnetic conditions.

  9. Audiovisual segregation in cochlear implant users.

    Directory of Open Access Journals (Sweden)

    Simon Landry

    Full Text Available It has traditionally been assumed that cochlear implant users de facto perform atypically in audiovisual tasks. However, a recent study that combined an auditory task with visual distractors suggests that only those cochlear implant users that are not proficient at recognizing speech sounds might show abnormal audiovisual interactions. The present study aims at reinforcing this notion by investigating the audiovisual segregation abilities of cochlear implant users in a visual task with auditory distractors. Speechreading was assessed in two groups of cochlear implant users (proficient and non-proficient at sound recognition, as well as in normal controls. A visual speech recognition task (i.e. speechreading was administered either in silence or in combination with three types of auditory distractors: i noise ii reverse speech sound and iii non-altered speech sound. Cochlear implant users proficient at speech recognition performed like normal controls in all conditions, whereas non-proficient users showed significantly different audiovisual segregation patterns in both speech conditions. These results confirm that normal-like audiovisual segregation is possible in highly skilled cochlear implant users and, consequently, that proficient and non-proficient CI users cannot be lumped into a single group. This important feature must be taken into account in further studies of audiovisual interactions in cochlear implant users.

  10. Integration and segregation in auditory scene analysis

    Science.gov (United States)

    Sussman, Elyse S.

    2005-03-01

    Assessment of the neural correlates of auditory scene analysis, using an index of sound change detection that does not require the listener to attend to the sounds [a component of event-related brain potentials called the mismatch negativity (MMN)], has previously demonstrated that segregation processes can occur without attention focused on the sounds and that within-stream contextual factors influence how sound elements are integrated and represented in auditory memory. The current study investigated the relationship between the segregation and integration processes when they were called upon to function together. The pattern of MMN results showed that the integration of sound elements within a sound stream occurred after the segregation of sounds into independent streams and, further, that the individual streams were subject to contextual effects. These results are consistent with a view of auditory processing that suggests that the auditory scene is rapidly organized into distinct streams and the integration of sequential elements to perceptual units takes place on the already formed streams. This would allow for the flexibility required to identify changing within-stream sound patterns, needed to appreciate music or comprehend speech..

  11. Segregation effects in DEEP2 galaxy groups

    CERN Document Server

    Nascimento, Raquel S; Lopes, Paulo A A

    2016-01-01

    We investigate segregation phenomena in galaxy groups in the range of $0.20.6$) redshift groups. Assuming that the color index ${(U-B)_0}$ can be used as a proxy for the galaxy type, we found that the fraction of blue (star-forming) objects is higher in the high-z sample, with blue objects being dominant at $M_{B}>-19.5$ for both samples, and red objects being dominant at $M_{B}<-19.5$ only for the low-z sample. Also, the radial variation of the red fraction indicates that there are more red objects with $Rsegregation, at the 99%c.l., for the low-z sample: redder and brighter galaxies present lower velocity dispersions than bluer and fainter ones. We also find a weaker evidence for spatial segregation between red and blue objects, at the 70%c.l. The analysis of the high-z sample reveals a different result: red and blue galaxies have velocity dispersion distributions not statistically distinc...

  12. Self-Segregation versus Clustering in the Evolutionary Minority Game

    Science.gov (United States)

    Hod, Shahar; Nakar, Ehud

    2002-06-01

    Complex adaptive systems have been the subject of much recent attention. It is by now well established that members (``agents'') tend to self-segregate into opposing groups characterized by extreme behavior. However, the study of such adaptive systems has mostly been restricted to simple situations in which the prize-to-fine ratio R equals unity. In this Letter we explore the dynamics of evolving populations with various different values of the ratio R, and demonstrate that extreme behavior is in fact not a generic feature of adaptive systems. In particular, we show that ``confusion'' and ``indecisiveness'' take over in times of depression, in which case cautious agents perform better than extreme ones.

  13. Identification of oligomer proanthocyanidins (F2) isolated from grape seeds as a formyl peptide receptor 1 partial agonist.

    Science.gov (United States)

    Yang, Jingyu; Wang, Qing; Zhao, Ruijun; Sun, Baoshan; Wang, Lihui; Hou, Yue; Li, Xiaoqin; Wu, Chunfu

    2013-04-01

    Formyl peptide receptor 1 (FPR1) plays an important role in the rapid progression of glioblastoma and has been considered as a molecular target for the treatment. Previously, we have shown that oligomer proanthocyanidins (F2, degree of polymerization 2-15), isolated from grape seeds, inhibited FPR1-mediated chemotaxis of U-87 glioblastoma cells. In the present study, we investigated the capacity of F2 to interact with FPR1. The cross attenuation of chemotaxis revealed that F2 shared FPR1 with formyl-methionyl-leucyl-phenylalanine (fMLF), which is a prototype agonist of FPR1. F2 was chemotactic for U-87 cells, and the chemotactic response was abolished when FPR1 gene was silenced or FPR1 was competitively occupied. We further show that F2 specifically blocked the binding of fluorescent agonist to FPR1. Interestingly, F2 exhibited the characteristic of a partial agonist for FPR1, as shown by its capacity to activate FPR1-mediated PI3K-PKC-MAPK pathways. Meanwhile, F2 also attenuated fMLF-triggered MAPK activation, suggesting that F2 could antagonize the effect of an agonist. Furthermore, F2 abolished the invasion of U-87 cells induced by fMLF. Thus, we have identified F2 as a novel, partial agonist for FPR1, which may be useful for glioblastoma therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Influenza A virus protein PB1-F2 exacerbates IFN-beta expression of human respiratory epithelial cells.

    Science.gov (United States)

    Le Goffic, Ronan; Bouguyon, Edwige; Chevalier, Christophe; Vidic, Jasmina; Da Costa, Bruno; Leymarie, Olivier; Bourdieu, Christiane; Decamps, Laure; Dhorne-Pollet, Sophie; Delmas, Bernard

    2010-10-15

    The PB1-F2 protein of the influenza A virus (IAV) contributes to viral pathogenesis by a mechanism that is not well understood. PB1-F2 was shown to modulate apoptosis and to be targeted by the CD8(+) T cell response. In this study, we examined the downstream effects of PB1-F2 protein during IAV infection by measuring expression of the cellular genes in response to infection with wild-type WSN/33 and PB1-F2 knockout viruses in human lung epithelial cells. Wild-type virus infection resulted in a significant induction of genes involved in innate immunity. Knocking out the PB1-F2 gene strongly decreased the magnitude of expression of cellular genes implicated in antiviral response and MHC class I Ag presentation, suggesting that PB1-F2 exacerbates innate immune response. Biological network analysis revealed the IFN pathway as a link between PB1-F2 and deregulated genes. Using quantitative RT-PCR and IFN-β gene reporter assay, we determined that PB1-F2 mediates an upregulation of IFN-β expression that is dependent on NF-κB but not on AP-1 and IFN regulatory factor-3 transcription factors. Recombinant viruses knocked out for the PB1-F2 and/or the nonstructural viral protein 1 (the viral antagonist of the IFN response) genes provide further evidence that PB1-F2 increases IFN-β expression and that nonstructural viral protein 1 strongly antagonizes the effect of PB1-F2 on the innate response. Finally, we compared the effect of PB1-F2 variants taken from several IAV strains on IFN-β expression and found that PB1-F2-mediated IFN-β induction is significantly influenced by its amino acid sequence, demonstrating its importance in the host cell response triggered by IAV infection.

  15. Analysis of Minor Component Segregation in Ternary Powder Mixtures

    Science.gov (United States)

    Asachi, Maryam; Hassanpour, Ali; Ghadiri, Mojtaba; Bayly, Andrew

    2017-06-01

    In many powder handling operations, inhomogeneity in powder mixtures caused by segregation could have significant adverse impact on the quality as well as economics of the production. Segregation of a minor component of a highly active substance could have serious deleterious effects, an example is the segregation of enzyme granules in detergent powders. In this study, the effects of particle properties and bulk cohesion on the segregation tendency of minor component are analysed. The minor component is made sticky while not adversely affecting the flowability of samples. The segregation extent is evaluated using image processing of the photographic records taken from the front face of the heap after the pouring process. The optimum average sieve cut size of components for which segregation could be reduced is reported. It is also shown that the extent of segregation is significantly reduced by applying a thin layer of liquid to the surfaces of minor component, promoting an ordered mixture.

  16. Analysis of Minor Component Segregation in Ternary Powder Mixtures

    Directory of Open Access Journals (Sweden)

    Asachi Maryam

    2017-01-01

    Full Text Available In many powder handling operations, inhomogeneity in powder mixtures caused by segregation could have significant adverse impact on the quality as well as economics of the production. Segregation of a minor component of a highly active substance could have serious deleterious effects, an example is the segregation of enzyme granules in detergent powders. In this study, the effects of particle properties and bulk cohesion on the segregation tendency of minor component are analysed. The minor component is made sticky while not adversely affecting the flowability of samples. The segregation extent is evaluated using image processing of the photographic records taken from the front face of the heap after the pouring process. The optimum average sieve cut size of components for which segregation could be reduced is reported. It is also shown that the extent of segregation is significantly reduced by applying a thin layer of liquid to the surfaces of minor component, promoting an ordered mixture.

  17. Evaluating segregation in granular filters for earth dams

    Energy Technology Data Exchange (ETDEWEB)

    Sutherland, K. [Cambridge Univ., Cambridge (United Kingdom); Grabinsky, M. [Toronto Univ., ON (Canada)

    2003-07-01

    This paper presented some case studies to illustrate the relationship between seepage problems encountered with earth dams and segregation of the dams' granular filters during construction. A literature review of segregation mechanisms was presented along with a laboratory investigation. The case studies showed that the current understanding of the impact of a given degree of segregation is relatively poor. The literature reveals that although segregation mechanisms are identified and analyzed, very few are likely to be predominant during earth dam construction. Laboratory studies show that a mathematical relationship can be established between the filter's grain size distribution curve and the potential degree of segregation. Therefore, a mathematical relationship can also be established with the potential for adverse dam performance. The authors proposed a field procedure which allows for the monitoring of segregation during construction by contractors and engineers. It also helps in deciding whether any segregated zones require replacement. 5 refs., 7 figs.

  18. Mutiscale Modeling of Segregation in Granular Flows

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jin [Iowa State Univ., Ames, IA (United States)

    2007-01-01

    Modeling and simulation of segregation phenomena in granular flows are investigated. Computational models at different scales ranging from particle level (microscale) to continuum level (macroscale) are employed in order to determine the important microscale physics relevant to macroscale modeling. The capability of a multi-fluid model to capture segregation caused by density difference is demonstrated by simulating grain-chaff biomass flows in a laboratory-scale air column and in a combine harvester. The multi-fluid model treats gas and solid phases as interpenetrating continua in an Eulerian frame. This model is further improved by incorporating particle rotation using kinetic theory for rapid granular flow of slightly frictional spheres. A simplified model is implemented without changing the current kinetic theory framework by introducing an effective coefficient of restitution to account for additional energy dissipation due to frictional collisions. The accuracy of predicting segregation rate in a gas-fluidized bed is improved by the implementation. This result indicates that particle rotation is important microscopic physics to be incorporated into the hydrodynamic model. Segregation of a large particle in a dense granular bed of small particles under vertical. vibration is studied using molecular dynamics simulations. Wall friction is identified as a necessary condition for the segregation. Large-scale force networks bearing larger-than-average forces are found with the presence of wall friction. The role of force networks in assisting rising of the large particle is analyzed. Single-point force distribution and two-point spatial force correlation are computed. The results show the heterogeneity of forces and a short-range correlation. The short correlation length implies that even dense granular flows may admit local constitutive relations. A modified minimum spanning tree (MST) algorithm is developed to asymptotically recover the force statistics in the

  19. Segregation of male-sterility alleles across a species boundary.

    Science.gov (United States)

    Weller, S G; Sakai, A K; Culley, T M; Duong, L; Danielson, R E

    2014-02-01

    Hybrid zones may serve as bridges permitting gene flow between species, including alleles influencing the evolution of breeding systems. Using greenhouse crosses, we assessed the likelihood that a hybrid zone could serve as a conduit for transfer of nuclear male-sterility alleles between a gynodioecious species and a hermaphroditic species with very rare females in some populations. Segregation patterns in progeny of crosses between rare females of hermaphroditic Schiedea menziesii and hermaphroditic plants of gynodioecious Schiedea salicaria heterozygous at the male-sterility locus, and between female S. salicaria and hermaphroditic plants from the hybrid zone, were used to determine whether male-sterility was controlled at the same locus in the parental species and the hybrid zone. Segregations of females and hermaphrodites in approximately equal ratios from many of the crosses indicate that the same nuclear male-sterility allele occurs in the parent species and the hybrid zone. These rare male-sterility alleles in S. menziesii may result from gene flow from S. salicaria through the hybrid zone, presumably facilitated by wind pollination in S. salicaria. Alternatively, rare male-sterility alleles might result from a reversal from gynodioecy to hermaphroditism in S. menziesii, or possibly de novo evolution of male sterility. Phylogenetic analysis indicates that some species of Schiedea have probably evolved separate sexes independently, but not in the lineage containing S. salicaria and S. menziesii. High levels of selfing and expression of strong inbreeding depression in S. menziesii, which together should favour females in populations, argue against a reversal from gynodioecy to hermaphroditism in S. menziesii.

  20. The relation between foF2 and ICF during the solar eclipse%日食期间foF2与ICF的相关性分析

    Institute of Scientific and Technical Information of China (English)

    张添益

    2001-01-01

    本文初步分析了1995年10月24日日食期间,F2层临界频率(foF2)和高频干扰重心频率(ICF)之间的相关性较差的原因.认为高频干扰重心频率ICF不仅受foF2的影响,还可能受D层吸收等因素影响.在探讨ICF与foF2的关系时,应综合加以考虑.

  1. Racial segregation and maternal smoking during pregnancy: a multilevel analysis using the racial segregation interaction index.

    Science.gov (United States)

    Yang, Tse-Chuan; Shoff, Carla; Noah, Aggie J; Black, Nyesha; Sparks, Corey S

    2014-04-01

    Drawing from both the place stratification and ethnic enclave perspectives, we use multilevel modeling to investigate the relationships between women's race/ethnicity (i.e., non-Hispanic white, non-Hispanic black, Asian, and Hispanic) and maternal smoking during pregnancy, and examine if these relationships are moderated by racial segregation in the continental United States. The results show that increased interaction with whites is associated with increased probability of maternal smoking during pregnancy, and racial segregation moderates the relationships between race/ethnicity and maternal smoking. Specifically, living in a less racially segregated area is related to a lower probability of smoking during pregnancy for black women, but it could double and almost triple the probability of smoking for Asian women and Hispanic women, respectively. Our findings provide empirical evidence for both the place stratification and ethnic enclave perspectives.

  2. EPR study of concentration dependence in Ce, Ce : La and Ce:Y doped SrF2

    NARCIS (Netherlands)

    Dankert, O.; Vainchtein, David; Datema, H.C.; den Hartog, Hendrik

    1995-01-01

    Experimental results of an EPR-study of the concentration dependence of the doubly integrated intensity and linewidth of the signals associated with tetragonal Ce3+-F--dipoles in Sr1-xCexF2+x, Sr-1-0.005-x Ce0.005LaxF2+0.005+x and Sr-1-0.005-x Ce0.005YxF2+0.005+x are presented. Both show a nonlinear

  3. F2 slope as a Perceptual Cue for the Front-Back Contrast in Standard Southern British English.

    Science.gov (United States)

    Chládková, Kateřina; Hamann, Silke; Williams, Daniel; Hellmuth, Sam

    2017-09-01

    Acoustic studies of several languages indicate that second-formant (F2) slopes in high vowels have opposing directions (independent of consonantal context): front [iː]-like vowels are produced with a rising F2 slope, whereas back [uː]-like vowels are produced with a falling F2 slope. The present study first reports acoustic measurements that confirm this pattern for the English variety of Standard Southern British English (SSBE), where /uː/ has shifted from the back to the front area of the vowel space and is now realized with higher midpoint F2 values than several decades ago. Subsequently, we test whether the direction of F2 slope also serves as a reliable cue to the /iː/-/uː/ contrast in perception. The findings show that F2 slope direction is used as a cue (additional to midpoint formant values) to distinguish /iː/ from /uː/ by both young and older Standard Southern British English listeners: an otherwise ambiguous token is identified as /iː/ if it has a rising F2 slope and as /uː/ if it has a falling F2 slope. Furthermore, our results indicate that listeners generalize their reliance on F2 slope to other contrasts, namely /ɛ/-/ɒ/ and /æ/-/ɒ/, even though F2 slope is not employed to differentiate these vowels in production. This suggests that in Standard Southern British English, a rising F2 seems to be perceptually associated with an abstract feature such as [+front], whereas a falling F2 with an abstract feature such as [-front].

  4. Long-term trends in the relation between daytime and nighttime values of foF2

    Directory of Open Access Journals (Sweden)

    A. D. Danilov

    2008-05-01

    Full Text Available The data from the vertical ionospheric sounding for 12 stations over the world were analyzed to find the relation between the values of foF2 for 02:00 LT and 14:00 LT of the same day. It is found that, in general, there exists a negative correlation between foF2(02 and foF2(14. The value of the correlation coefficient R(foF2 can be in some cases high enough and reach minus 0.7–0.8. The value of R(foF2 demonstrates a well pronounced seasonal variations, the highest negative values being observed at the equinox periods of the year. It is also found that R(foF2 depends on geomagnetic activity: the magnitude of R(foF2 is the highest for the choice of only magnetically quiet days (Ap<6, decreasing with the increase of the limiting value of Ap. For a fixed limitation on Ap, the value of R(foF2 depends also on solar activity. Apparently, the effects found are related to thermospheric winds. Analysis of long series of the vertical sounding data shows that there is a long-term trend in R(foF2 with a statistically significant increase in the R(foF2 magnitude after about 1980. Similar analysis is performed for the foF2(02/foF2(14 ratio itself. The ratio also demonstrates a systematic trend after 1980. Both trends are interpreted in terms of long-term changes in thermospheric circulation.

  5. NMR-based metabolic profiling of rice wines by F(2)-selective total correlation spectra.

    Science.gov (United States)

    Koda, Masanori; Furihata, Kazuo; Wei, Feifei; Miyakawa, Takuya; Tanokura, Masaru

    2012-05-16

    In this study, we performed NMR-based metabolic profiling of major rice wines (Japanese sake, Chinese Shaoxing wine, and Korean makgeolli). In the (1)H NMR spectra, the rice wines showed broad resonances in the region of about 7.9-9.0 ppm. These resonances showed many and complex correlations with approximately 0.5-4.5 ppm in the F(2)-selective TOCSY (total correlation spectroscopy) spectra, and these correlations were attributed mainly to peptides. These spectral patterns were characteristic of individual rice wines, and the combination of F(2)-selective TOCSY spectra and principal component analysis enabled us to classify the rice wine species. Furthermore, it also provided information about raw materials, namely, what type of koji (rice koji or wheat koji) was used. These spectra may be useful as a new "fingerprint" for quality control or food authentication.

  6. Cryogenic Ho:CaF2 laser pumped by Tm:fiber laser

    Science.gov (United States)

    Jelínek, Michal; Kubeček, Václav; Ma, Weiwei; Zhao, Beibei; Jiang, Dapeng; Su, Liangbi

    2016-06-01

    The laser operation in the pulsed as well as continuous-wave regime of a modified-Bridgeman-grown 0.5 at.% Ho:CaF2 crystal at 83 K pumped by a Tm:fiber laser is reported. The maximum output power was 2.37 W at 2060 nm or 1.3 W at 2110 and 2130 nm. Continuous tuning range over 90 nm from 2030 to 2120 nm was achieved using a birefringent filter. The Ho:CaF2 fundamental spectroscopic properties as absorption and fluorescence spectra at 83 and 293 K are also presented.

  7. 七色炫灯翻盖萌作三星Nori F2

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    三星电子去年在韩国市场推出一款以鲜艳色彩和LED炫灯为主打的翻盖手机Nori F。如今.三星又推出了该机的续作Nori F2(型号SHW—A280),该机仍然以年轻用户为目标客户群体.相对于前代产品.F2增加了七彩炫灯功能,用户可对来电和短信定制7种个性化的闪灯.效果也够萌。

  8. Excited state absorption of Sm2+ in SrF2

    Science.gov (United States)

    Payne, Stephen A.; Chase, L. L.; Krupke, William F.

    1988-10-01

    The excited state absorption spectrum of Sm2+ in SrF2 has been observed. The absorption peaks associated with the 5D0(4f6) excited state were found to be displaced by approximately 3000 cm-1 from the absorption bands arising from the 7F0(4f6) ground state (after taking the 5D0-7F0 energy separation into account). The observed peak separation is ascribed to the 4f-5d exchange interaction. From the measured peak positions, the exchange energy for the Sm2+ impurity was determined to be about the same order of magnitude as expected for the free ion. The implications of the properties of the excited state absorption bands for the performance of the SrF2:Sm2+ laser are considered.

  9. Proximity effects in superconducting triplet spin-valve F2/F1/S

    Energy Technology Data Exchange (ETDEWEB)

    Deminov, R.G., E-mail: Raphael.Deminov@kpfu.ru [Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Tagirov, L.R. [Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Institut für Physik, Universität Augsburg, Augsburg D-86159 (Germany); Gaifullin, R.R. [Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Karminskaya, T.Yu.; Kupriyanov, M.Yu. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow 119992 (Russian Federation); Fominov, Ya.V. [Landau Institute for Theoretical Physics RAS, Moscow 119334 (Russian Federation); Golubov, A.A. [Faculty of Science and Technology and MESA+ Institute of Nanotechnology, University of Twente, P.O. Box 217, Enschede 7500 AE (Netherlands)

    2015-01-01

    We investigate the critical temperature T{sub c} of F2/F1/S trilayers (Fi is a ferromagnetic metal and S is a singlet superconductor), where the long-range triplet superconducting component is generated at noncollinear magnetizations of the F layers. In this paper we demonstrate a possibility of the spin-valve effect mode selection (standard switching effect, the triplet spin-valve effect or reentrant T{sub c}(α) dependence) by the variation of the F2/F1 interface transparency. - Highlights: • T{sub c} of FFS trilayer as a function of angle between magnetizations is calculated. • T{sub c} of FFS structure for arbitrary FF interface transparencies γ{sub B} is calculated. • Possibility of the spin-valve effect mode selection by the variation of γ{sub B} is shown.

  10. Nanostructuring CaF2 surfaces with slow highly charged ions

    Science.gov (United States)

    El-Said, A. S.; Wilhelm, R. A.; Heller, R.; Ritter, R.; Wachter, G.; Facsko, S.; Lemell, C.; Burgdörfer, J.; Aumayr, F.

    2014-04-01

    In recent years the potential of slow highly charged ions (HCI) as tools for nanostructuring purposes has received considerable attention and a wide range of material classes, from insulating ionic crystals, polymers and ultrathin films, to semiconducting and conducting substrates have been investigated regarding their response to individual HCI impact. For the majority of investigated materials, however, consistent theoretical modeling to supplement with experimental evidence and to satisfactorily explain the complete physical process from ion approach and impact to the formation of an individual nanostructure is still lacking. CaF2, from both an experimental and theoretical point of view, might be considered the most thoroughly investigated material. Combining results from numerous studies has allowed for the generation of a "phase diagram" for nanostructuring of CaF2 in dependence of ion beam parameters. This paves the way for a first unified picture, as implications from this phase diagram should be applicable to similar materials as well.

  11. The Importance of Magnetic Reflection Condition and Polarization Factor: Case Study of MnF2

    Directory of Open Access Journals (Sweden)

    A. Purwanto

    2010-08-01

    Full Text Available Neutron diffraction has been widely accepted as a versatile tool to investigate magnetic structure of crystalline materials, which contribute significantly to the scientific and technological advances. Starting from a general formulation of the magnetic structure factor, one can often simplify the formulation depending on the crystallographic structure and the magnetic wave propagation vector of the sample. The simplification allows magnetic moment coupling and polarization deduction without the need of the refinement process. This paper elaborates such simplification for MnF2 to provide the determination of the magnetic moment coupling and polarization direction simply based on the reflection condition and polarization factor. The determination of the magnetic structure excluding its magnitude by the reflection condition and polarization factor is much more conclusive than by any magnetic structure refinement. Furthermore, MnF2 illustrates a rare compound that has antiferromagnetic structure with zero magnetic wave propagation vector, i.e.; it has the same antiferromagnetic and crystallographic unit cell.

  12. Comparison of the ionospheric F2 peak height between ionosonde measurements and IRI2016 predictions over China

    Science.gov (United States)

    Zhao, Xiukuan; Ning, Baiqi; Zhang, Man-Lian; Hu, Lianhuan

    2017-10-01

    The International Reference Ionosphere (IRI) is the most frequently used community empirical model. The latest version IRI2016 provides three options for the F2 peak height hmF2: AMTB2013, SHU-2015, and BSE-1979. In this paper, we used the hmF2 data derived by the ionosondes at Mohe, Beijing, Wuhan and Sanya ranging from year 2007 to 2016 to assess the performance of these three options in the model. The results show that the variability of the observed hmF2 versus local time, seasons and levels of solar activity could be reproduced well by the three options. However, the SHU-2015 option performs best at these four stations, followed by BSE-1979, and the AMTB2013 option is worst. Generally, the AMTB2013 and BSE-1979 options overestimate the hmF2 values, while the SHU-2015 option mainly underestimates the hmF2 values. This is the first evaluations of the three IRI2016 hmF2 options by manually scaled ionosonde data over China area to our knowledge. Overall, we recommend the usage of SHU-2015 hmF2 option over China region when using IRI2016 model in terms of hmF2 calculation.

  13. Adsorption behaviour of PuF6 on UO2F2 by the use of 236Pu

    Science.gov (United States)

    Sato, Nobuaki; Matsuda, Minoru; Mitsugashira, Toshiaki; Kirishima, Akira

    2010-03-01

    To know the behavior of plutonium in the fluoride volatility process (FLUOREX PROCESS) for the spent nuclear fuel, both UO2 and PuO2 are fluorinated by fluorine forming volatile UF6 and PuF6, respectively. Then PuF6 is separated and recovered from UF6 by using adsorption materials such as uranyl fluoride UO2F2. In this paper, adsorption behavior of PuF6on UO2F2 was examined by the use of 236Pu tracer. First, the stability of UO2F2 in F2atmosphere was analyzed by TG-DTA method showing that uranium volatilized completely over 350 °C by the formation of UF6 and the adsorption of plutonium by UO2F2 should be done at temperatures lower than 250 °C. The behavior of PtF6 as a chemical analogue of PuF6 was also conducted for comparison and it showed that the deposition of PtF4 on UO2F2 at 200 °C. When the 236Pu doped U3O8 was reacted with 10%F2-He gas, the PuF6 vaporized at ca. 600 °C. Then adsorption of 236Pu on UO2F2 was observed by α ray measurement. The adsorption mechanism of Pu on UO2F2 was discussed with experimental data and thermodynamic consideration.

  14. Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum) Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

    Science.gov (United States)

    Xu, Xiaomei; Chao, Juan; Cheng, Xueli; Wang, Rui; Sun, Baojuan; Wang, Hengming; Luo, Shaobo; Xu, Xiaowan; Wu, Tingquan; Li, Ying

    2016-01-01

    Phytophthora root rot caused by Phytophthora capsici (P. capsici) is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS). Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334) and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399) were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3) was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA) and Specific Length Amplified Fragment sequencing (SLAF-seq) provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR) markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away) and P52-11-41 (1.1 cM). A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

  15. [Induced abortion using prostaglandin E2 and F2alpha gel].

    Science.gov (United States)

    Lippert, T H; Modly, T

    1974-01-01

    In this study of 20 patients in the 13th-17th week of pregnancy abortion was induced with intrauterine, extraamniotic application of prostaglandins (PG) E2 or F2 in gel form. The gel composition was as follows: 4% tylose MH 300, 2% glycerine, 1% chlorhexidine digluconate, 83% sterile distilled water and 10% PG stock solution. Both PGE2 and PGF2 gels were used. Final concentration was 2.5 mg E2 or 2.5 mg F2 per g of gel. Gel was applied via transcervical, extraamniotic polyethylene catheter every 2-3 hours. Results: PGE2-gel was used in 14 cases. After 3-4 applications both fetus and placenta were expelled. Average dose used was 4.6 mg E2/patient. First contractions started in 30 minutes; induction to expulsion time was 11 hours 35 minutes. F2-gel given to 6 patients resulted in expulsion of the fetus in all cases but placenta needed removal by curettage in 4 patients. Average dose per patient was 17.7 mg of F2; first contractions in 30 minutes, average expulsion time 17 hours 38 minutes. With both PGs there were painful contractions which were controlled with a combination of pentazocine and Valium. PGE2 caused vomiting in 5 patients. No increased bleeding or postabortion infection occurred. Follow-up curettage was done in all patients to ensure removal of all tissues. Overall evaluation of the PG-gels was considered good. PG stability in gel form is good; during 8 months of preservation in sterile aluminum tubes at -25 degrees Celsius no decline in clinical effectiveness was noted. The gel application is less expensive than the slow-injection pump method.

  16. Scientific and regulatory standards for assessing product performance using the similarity factor, f2.

    Science.gov (United States)

    Stevens, Ruth E; Gray, Vivian; Dorantes, Angelica; Gold, Lynn; Pham, Loan

    2015-03-01

    The similarity factor, f2, measures the sameness of dissolution profiles. The following commentary is an overview of discussions and presentations from a group of industry and US regulatory experts that have integrated the science and regulatory research and practice for assessing product performance, particularly for modified-release (MR) dosage forms, using f2. For a drug development sponsor or applicant with an orally complex dosage formulation, it is critical to understand dissolution methods and the similarity factor and how and/or when to apply it in their NDA, ANDA, or PMA submission. As part of any regulatory submission, it is critical to justify that the product performance has not been impacted by any change in the manufacturing process and/or the delayed and/or prolonged drug release characteristics compared to a similar conventional or another orally complex dosage form. The purposes of this document are (1) to provide a description of appropriate dissolution methods, how is the f2 calculated and how it can be used to justify product performance similarity, or not; (2) to provide an overview of alternative methods available for dissolution profile comparisons, and (3) to illustrate how applying these concepts in a focused way supports approval of submissions and regulatory dossiers and aligns them with on-going science and regulatory initiatives. A case study will be used as an example to demonstrate how dissolution testing and the f2 calculation results can impact regulatory outcomes from an NDA (505(b)(1)), NDA (505(b)(2)), ANDA (505(j)), supplemental NDAs/ANDAs, or PMA perspective.

  17. A BaF2 crystal array for high energy -ray measurements

    Indian Academy of Sciences (India)

    A Ray; S R Banerjee; P Das

    2001-07-01

    We shall discuss about the scientific motivation and construction of a 7 × 7 BaF2 crystal array at Variable Energy Cyclotron Centre, Calcutta. This detector would be used to measure high energy -ray photons from GDR decay and proton–neutron bremsstrahlung reactions at the present 88'' cyclotron and upcoming superconducting cyclotron at VECC, Calcutta. This detector can also be used to measure photons from quark–gluon plasma at the relativistic heavy ion collider (RHIC) in USA.

  18. Comparison of On-line and F2F Education Methods in Teaching Computer Programming

    OpenAIRE

    2013-01-01

    lthough online education provides opportunities to people who traditionally do not have access to universities, there is a need for more empirical studies to gain better understanding on how to deliver quality online education, especially when the subject of the course is related with IT. Learning to program is a complicated process. This study aims to find out the difference between students’ performance in online and face-to-face (F2F) settings during a computer programming in the fall seme...

  19. Diode-pumped Yb,Y:CaF2 laser mode-locked by monolayer graphene

    Science.gov (United States)

    Zhu, Hongtong; Liu, Jie; Jiang, Shouzhen; Xu, Shicai; Su, Liangbi; Jiang, Dapeng; Qian, Xiaobo; Xu, Jun

    2015-12-01

    The large-area and high-quality monolayer graphene saturable absorber with a sandwich structure is prepared by the chemical vapor deposition technique. Using graphene saturable absorber, the mode locking operation of a diode-pumped Yb,Y:CaF2 laser is demonstrated. Without extra negative dispersion elements, 4.8 ps pulses are yielded at 1051 nm. The pulse repetition rate is 60 MHz.

  20. Agraphia and acalculia after a left prefrontal (F1, F2) infarction.

    OpenAIRE

    Tohgi, H; Saitoh, K.; S. Takahashi(Kobe University, J-657-8501 Kobe, Japan); Takahashi, H; Utsugisawa, K; Yonezawa, H.; Hatano, K.; Sasaki, T.

    1995-01-01

    A patient presented with agraphia and acalculia associated with a left frontal (F1, F2) infarction. He made mainly phonological but also lexical errors in writing (syllabograms), but his ability to write kanji (morphograms) was relatively preserved. Although he could add and subtract numbers, he could neither multiply nor divide them because of a difficulty in retrieving the multiplication tables and calculation procedures. Positron emission tomography showed decreased cerebral blood flow and...

  1. Evolution of dislocation structure and modelling of deformation resistance in CaF2 single crystals

    OpenAIRE

    Sadrabadi, Peiman

    2007-01-01

    he evolution of dislocation structure during plastic deformation in pure 111}-oriented CaF2 single crystals was investigated at constant strain rate (10−5 s−1) and constant stress (1 < / MPa < 22) in the temperature range of 0.5 < T/Tm < 0.8. The steady state and transient deformation behavior of the material is described by the composite model on the basis of microstructural data. In the following sections the important conclusions are briefly summarized. Microstructure evolution...

  2. Moments of structure functions for $N_f=2$ near the physical point

    CERN Document Server

    Bali, G S; Gläßle, B; Göckeler, M; Najjar, J; Rödl, R; Schäfer, A; Schiel, R; Sternbeck, A; Söldner, W

    2013-01-01

    We report on our on-going study of the lower moments of iso-vector polarised and unpolarised structure functions, $g_A$ and $\\langle x\\rangle_{u-d}$, respectively, and the iso-vector scalar and tensor charge, for $N_f=2$ non-perturbatively improved clover fermions. With pion masses which go down to about 150 MeV, we investigate finite volume effects and excited state contributions.

  3. On the order of the deconfining transition in N_f=2 QCD

    CERN Document Server

    D'Elia, M; Pica, C

    2004-01-01

    A careful study is made on the lattice of the phase diagram of QCD with two staggered flavors, to investigate the order of the chiral transition of N_f=2 QCD. The specific heat and the susceptibility of the chiral condensate are determined for different spatial sizes of the system, and a finite size scaling analysis provides a determination of the (pseudo)critical indices. The result is a strong indication that the chiral transition is first order.

  4. $_{3}$F$_{2}$(1) hypergeometric function and quadratic R-matrix algebra

    CERN Document Server

    Kuznetsov, V B

    1994-01-01

    We construct a class of representations of the quadratic R-matrix algebra, given by the reflection equation with the spectral parameter, in terms of certain ordinary difference operators. These operators turn out to act as parameter shifting operators on the 3_F_2(1) hypergeometric function and its limit cases and on classical orthogonal polynomials. The relationship with the factorization method will be discussed.

  5. $^3P_2$-$^3F_2$ Pairing in Dense Neutron Matter The Spectrum of Solutions

    CERN Document Server

    Zverev, M V; Khodel, V A

    2003-01-01

    The $^3P_2$-$^3F_2$ pairing model is generally considered to provide an adequate description of the superfluid states of neutron matter at densities some 2-3 times that of saturated symmetrical nuclear matter. The problem of solving the system of BCS gap equations expressing the $^3P_2$-$^3F_2$ model is attacked with the aid of the separation approach. This method, developed originally for quantitative study of S-wave pairing in the presence of strong short-range repulsions, serves effectively to reduce the coupled, singular, nonlinear BCS integral equations to a set of coupled algebraic equations. For the first time, sufficient precision becomes accessible to resolve small energy splittings between the different pairing states. Adopting a perturbative strategy, we are able to identify and characterize the full repertoire of real solutions of the $^3P_2$-$^3F_2$ pairing model, in the limiting regime of small tensor-coupling strength. The P-F channel coupling is seen to lift the striking parametric degeneracie...

  6. Sintering of CaF 2 pellets as nuclear fuel analog for surface stability experiments

    Science.gov (United States)

    Godinho, José R. A.; Piazolo, Sandra; Stennett, Martin C.; Hyatt, Neil C.

    2011-12-01

    To enable a detailed study of the influence of microstructure and surface properties on the stability of spent nuclear fuel, it is necessary to produce analogs that closely resemble nuclear fuel in terms of crystallography and microstructure. One such analog can be obtained by sintering CaF 2 powder. This paper reports the microstructures obtained after sintering CaF 2 powders at temperatures up to 1240 °C. Pellets with microstructure, density and pore structure similar to that of UO 2 spent nuclear fuel pellets were obtained in the temperature range between 900 °C and 1000 °C. When CaF 2 was sintered above 1100 °C the formation of CaO at the grain boundaries caused the disintegration of the pellet due to hydration occurring after sintering. First results from a novel set-up of dissolution experiments show that changes in roughness, dissolution rate and etch pit shape of fluorite surfaces are strongly dependent on the crystallographic orientation of the expose surface. Consequently, the differences observed for each orientation will affect the overall dissolution rate and will lead to uncertainties in the estimation of dissolution rates of spent nuclear fuel.

  7. Growth and characterization of epitaxial SrF2 on InP(100)

    Science.gov (United States)

    Sinharoy, S.; Hoffman, R. A.; Rieger, J. H.; Warner, J. D.; Bhasin, K. B.

    1986-01-01

    The epitaxial growth of 100-262.5-nm SrF2 films on n-type and p-type (100)InP in a conventional baked UHV system at base pressure about 200 ptorr, temperature 250-350 C, and growth rate from less than 100 to about 200 pm/s. Substrates are chemicomechanically polished, degreased, bombarded with 500-eV Ar ions for 3-4 min at 350 C, and annealed for 23-30 min at 350 C, producing a slightly In-rich (In/P = 1.02) In-island-free surface with a (4 x 1) or (1 x 1) LEED structure. Films grown at 350 C and less than 100 pm/s are found to be smooth and free of cracks in most cases, with a highly faceted (1 x 1) LEED structure. The electrical properties of the SrF2 films are found to be acceptable only when the ohmic contacts are applied prior to the substrate prior to SrF2 growth.

  8. On the diurnal variability in F2-region plasma density above the EISCAT Svalbard radar

    Directory of Open Access Journals (Sweden)

    J. Moen

    2008-08-01

    Full Text Available Two long runs of EISCAT Svalbard Radar (ESR, in February 2001 and October 2002, have been analysed with respect to variability in the F2 region peak density and altitude. The diurnal variation in the F2 peak density exhibits one maximum around 12:00 MLT and another around 23:00 MLT, consistent with solar wind controlled transport of EUV ionized plasma across the polar cap from day to night. High density plasma patch material is drawn in through the cusp inflow region independent of IMF BY. There is no apparent IMF BY asymmetry on the intake of high density plasma, but the trajectory of its motion is strongly BY dependent. Comparison with the international reference ionosphere model (IRI2001 clearly demonstrates that the model does not take account of the cross-polar transport of F2-region plasma, and hence has limited applicability in polar cap regions.

  9. One-step ahead prediction of foF2 using time series forecasting techniques

    Directory of Open Access Journals (Sweden)

    A. Belehaki

    2005-11-01

    Full Text Available In this paper the problem of one-step ahead prediction of the critical frequency (foF2 of the middle-latitude ionosphere, using time series forecasting methods, is considered. The whole study is based on a sample of about 58000 observations of foF2 with 15-min time resolution, derived from the Athens digisonde ionograms taken from the Digisonde Portable Sounder (DPS4 located at Palaia Penteli (38° N, 23.5° E, for the period from October 2002 to May 2004. First, the embedding dimension of the dynamical system that generates the above sample is estimated using the false nearest neighbor method. This information is then utilized for the training of the predictors employed in this study, which are the linear predictor, the neural network predictor, the persistence predictor and the k-nearest neighbor predictor. The results obtained by the above predictors suggest that, as far as the mean square error is considered as performance criterion, the first two predictors are significantly better than the latter two predictors. In addition, the results obtained by the linear and the neural network predictors are not significantly different from each other. This may be taken as an indication that a linear model suffices for one step ahead prediction of foF2.

  10. Excited state absorption of Sm2+ in SrF2 and SrCl2

    Science.gov (United States)

    Payne, Stephen A.; Chase, L. L.; Krupke, William F.; Boatner, L. A.

    1988-06-01

    The excited state absorption spectrum of Sm2+ diluted as an impurity in the single crystal hosts SrF2 and SrCl2 has been observed. The absorption peaks associated with the 5D0(4f6) excited state were found to be displaced by approximately 3000 cm-1 from the absorption bands arising from the 7F0(4f6) ground state when the 5D0-7F0 energy was taken into account. The observed peak separation is ascribed to the 4f-5d exchange interaction. From the measured peak positions and band intensities, the exchange energy for the Sm2+ impurity in the two host crystals was determined to be about the same order of magnitude as that expected for the free ion. The implications of the properties of the excited state absorption bands for the performance of CaF2:Sm2+ and SrF2:Sm2+ lasers are considered.

  11. Psychoacoustical and ear canal cancellation of (2f1-f2)-distortion products.

    Science.gov (United States)

    Zwicker, E; Harris, F P

    1990-06-01

    Level and phase of the (2f1-f2)-difference tone were measured as a function of primary-tone level using the psychoacoustical method of cancellation and the objective method of emission cancellation for four frequency separations of f1 = 1620 Hz and f2 in four subjects. Differences between hearing- and emission-cancellation levels ranged from 60-33 dB as delta f = f2-f1 increased from 180 to 432 Hz. For smaller separations of the primaries, phase changes for emission cancellation covered a wide range and had sharp "steps," whereas for hearing cancellation, the phase varied only slightly. With wider separations of the primaries, the phase became more varied for hearing cancellation and more homogeneous for emission cancellation. Both emission- and hearing-cancellation level functions were nonmonotonic as a function of constant SL1 and varied SL2. Remarkable phase shifts always appeared near minima in level at all separations of the primaries for emission cancellation. Four sources may be contributing to the differences in results: (a) the frequency-dependent attenuation of the middle-ear transfer function, (b) the frequency-dependent mismatch of the acoustical impedances at the eardrum, (c) the frequency dependence of the microphone's sensitivity mounted within the probe, and (d) the different reaction of active nonlinear cochlear processes on the hearing- and emission-cancellation tones.

  12. [Cardiovascular effect of 15(S)-15-methyl-prostaglandin F2alpha].

    Science.gov (United States)

    Retzke, U; Schwarz, R

    1978-01-01

    The reaction of the cardiovascular system on one intramuscular injection of 250 microgram 15-methyl-prostaglandin F2alpha was examined in 14 normotensive healthy pregnant women between 7th and 11th weeks of gestation with the method of quantitative sphygmometry with unbloody graphic recording of arterial blood pressure and direct electronic determination of velocity of aortic pulse wave. The tests were done in 10 patients in intervals of 5 minutes for one hour and in 4 subjects for 12 hours in intervals of one hour. Systolic blood pressure remains nearly constant, but diastolic blood pressure increases and then decreases significantly. Heart rate decreases significantly. Aortic pulse wave velocity decreases in a characteristic manner. Analogous to the biphasic behaviour of blood pressure cardiac output decreases significantly, but then increases insignificantly. The inverse changes of total peripheral resistance are insignificant. Comparing these reactions with the cardiovascular effects of prostaglandin F2alpha or E2, 15-methyl-prostaglandin F2alpha shows the smallest circulatory alterations.

  13. Effect of CaF2 content on rate of fluoride release from filled resins.

    Science.gov (United States)

    Anusavice, K J; Zhang, N-Z; Shen, C

    2005-05-01

    Information on the time-dependent release of fluoride from filled resins containing fluoride particles as a function of particle content and solution pH is limited. This study characterized the fluoride ion release from filled resins containing CaF2 particles as a function of filler content and pH. Urethane dimethacrylate and triethylene glycol dimethacrylate resins were used to make filled-resin disks containing 9.09, 23.08, or 33.33 mass% CaF2 filler. Fluoride ion release for the 9.09 mass% concentration was independent of pH. Increasing the filler content from 9.09 to 33.33 mass% increased the fluoride release rate in pH 4.0 buffer solution, because of greater surface degradation. Fluoride ion release from disks stored in pH 6.0 buffer solutions occurred mainly by diffusion from disk surfaces, while fluoride release from disks in pH 4.0 buffers was controlled by diffusion from disk surfaces and degeneration of the resin matrix, which exposed more CaF2 particle surface area.

  14. Evaluation Software for BaF2 Detector Array Electronics at CSNS-WNS

    Science.gov (United States)

    Zhang, Yaxi; Cao, Ping; Wang, Qi; Zhang, Deliang; He, Bing; Qi, Xincheng; An, Qi

    2017-06-01

    The “in programming barium fluoride (BaF2) detector array” is one of the experiment facilities at China Spallation Neutron Source-White Neutron Sources, which is designed for the measurement of neutron capture cross section with high accuracy. It consists of 92 crystal elements with completely 4π solid-angle coverage, which needs 92 analog channels and 92 digitization channels for data acquisition. Accordingly, the readout electronics is comprised with four distributed readout PXIe crates, containing 46 field digitization modules (FDMs). Each FDM supports two valid channels for signal digitizing. In this paper, evaluation software is designed for evaluating the performance of BaF2 readout electronics. It focuses on evaluating the performance of data transmission, waveform digitizing, and working status monitoring. Test results show that the evaluation software can correctly acquire and assemble data from the BaF2 readout system and evaluate the analog digital converter (ADC) performance under ADC test mode. FDMs in the readout system can also be monitored and controlled by this software in real time.

  15. The essential role of charge-shift bonding in hypervalent prototype XeF2

    Science.gov (United States)

    Braïda, Benoît; Hiberty, Philippe C.

    2013-05-01

    Hypervalency in XeF2 and isoelectronic complexes is generally understood in terms of the Rundle-Pimentel model (which invokes a three-centre/four-electron molecular system) or its valence bond version as proposed by Coulson, which replaced the old expanded octet model of Pauling. However, the Rundle-Pimentel model is not always successful in describing such complexes and has been shown to be oversimplified. Here using ab initio valence bond theory coupled to quantum Monte Carlo methods, we show that the Rundle-Pimentel model is insufficient by itself in accounting for the great stability of XeF2, and that charge-shift bonding, wherein the large covalent-ionic interaction energy has the dominant role, is a major stabilizing factor. The energetic contribution of the old expanded octet model is also quantified and shown to be marginal. Generalizing to isoelectronic systems such as ClF3, SF4, PCl5 and others, it is suggested that charge-shift bonding is necessary, in association with the Rundle-Pimentel model, for hypervalent analogues of XeF2 to be strongly bonded.

  16. Segregation of helicity in inertial wave packets

    Science.gov (United States)

    Ranjan, A.

    2017-03-01

    Inertial waves are known to exist in the Earth's rapidly rotating outer core and could be important for the dynamo generation. It is well known that a monochromatic inertial plane wave traveling parallel to the rotation axis (along positive z ) has negative helicity while the wave traveling antiparallel (negative z ) has positive helicity. Such a helicity segregation, north and south of the equator, is necessary for the α2-dynamo model based on inertial waves [Davidson, Geophys. J. Int. 198, 1832 (2014), 10.1093/gji/ggu220] to work. The core is likely to contain a myriad of inertial waves of different wave numbers and frequencies. In this study, we investigate whether this characteristic of helicity segregation also holds for an inertial wave packet comprising waves with the same sign of Cg ,z, the z component of group velocity. We first derive the polarization relations for inertial waves and subsequently derive the resultant helicity in wave packets forming as a result of superposition of two or more waves. We find that the helicity segregation does hold for an inertial wave packet unless the wave numbers of the constituent waves are widely separated. In the latter case, regions of opposite color helicity do appear, but the mean helicity retains the expected sign. An illustration of this observation is provided by (a) calculating the resultant helicity for a wave packet formed by superposition of four upward-propagating inertial waves with different wave vectors and (b) conducting the direct numerical simulation of a Gaussian eddy under rapid rotation. Last, the possible effects of other forces such as the viscous dissipation, the Lorentz force, buoyancy stratification, and nonlinearity on helicity are investigated and discussed. The helical structure of the wave packet is likely to remain unaffected by dissipation or the magnetic field, but can be modified by the presence of linearly stable stratification and nonlinearity.

  17. Isothermal Gravitational Segregation: Algorithms and Specifications

    DEFF Research Database (Denmark)

    Halldórsson, Snorri; Stenby, Erling Halfdan

    2000-01-01

    New algorithms for calculating the isothermal equilibrium state of reservoir fluids under the influence of gravity are presented. Two types of specifications are considered: the specification of pressure and composition at a reference depth; and the specification of the total overall content...... of the reservoir, along with the reservoir geometry. It is shown how both types of calculations can be performed in an efficient and robust manner using volume-based thermodynamics. The new method makes it possible to evaluate the influence of reservoir geometry and gravity segregation on the hydrocarbon reserves...

  18. Selection processes in a citrus hybrid population using RAPD markers

    Directory of Open Access Journals (Sweden)

    Oliveira Roberto Pedroso de

    2003-01-01

    Full Text Available The objective of this work was to evaluate the processes of selection in a citrus hybrid population using segregation analysis of RAPD markers. The segregation of 123 RAPD markers between 'Cravo' mandarin (Citrus reticulata Blanco and 'Pêra' sweet orange (C. sinensis (L. Osbeck was analysed in a F1 progeny of 94 hybrids. Genetic composition, diversity, heterozygosity, differences in chromosomal structure and the presence of deleterious recessive genes are discussed based on the segregation ratios obtained. A high percentage of markers had a skeweness of the 1:1 expected segregation ratio in the F1 population. Many markers showed a 3:1 segregation ratio in both varieties and 1:3 in 'Pêra' sweet orange, probably due to directional selection processes. The distribution analysis of the frequencies of the segregant markers in a hybrid population is a simple method which allows a better understanding of the genetics of citrus group.

  19. High-pressure polymorphism of Pb F2 to 75 GPa

    Science.gov (United States)

    Stan, Camelia V.; Dutta, Rajkrishna; White, Claire E.; Prakapenka, Vitali; Duffy, Thomas S.

    2016-07-01

    Lead fluoride, Pb F2 , was investigated experimentally in the laser-heated diamond anvil cell by x-ray diffraction to pressures of 75 GPa at room temperature and to 64.5 GPa and 2430 K, as well as through first-principles density functional theory calculations up to 70 GPa. During room temperature compression, no discontinuous changes in the x-ray diffraction pattern or volume were observed, but the lattice parameters displayed highly anomalous trends between 10-22 GPa with enhanced compressibility along the a direction and reduced or even negative compressibility along b and c . Theoretical calculations of valence electron densities at 22 GPa showed that α -Pb F2 underwent a pressure-induced isosymmetric phase transition to a postcotunnite C o2Si structure and also revealed the detailed atomic rearrangements associated with the development of an extra Pb-F bond in the high-pressure phase. Our x-ray results and theoretical calculations are consistent with an isosymmetric phase transition smoothly occurring over 10-22 GPa rather than abruptly as previously suggested. The characteristic values for the cell constants a /c and (a +c )/b , which are used to distinguish among cotunnite-, C o2Si -, and N i2In -type phases, require modification based on our results. An equation of state fit yields a bulk modulus, K0, of 72(3) GPa for the cotunnite-type, and an ambient-pressure volume, V0, of 182 (2 ) Å3 , and K0=81 (4 ) GPa for the C o2Si -type phase when fixing the pressure derivative of the bulk modulus, K0 '=4 . Upon heating above 1200 K at pressures at or above 25.9 GPa, Pb F2 partially transformed to the hexagonal N i2In -type phase but wholly or partially reverted back to C o2Si -type phase upon temperature quench. From 43-65 GPa, nearly complete transformation to the N i2In -type Pb F2 was observed at high temperature, but the material partially transformed back to the orthorhombic phase upon temperature quench. Our results show that high-pressure behavior of Pb F

  20. The F1-F2 vowel chart for Czech whispered vowels a, e, i, o, u.

    Science.gov (United States)

    Grepl, Michal; Furst, Tomas; Pesak, Josef

    2007-12-01

    The aim of this contribution is to present the formant chart of the Czech vowels a, e, i, o, u and show that this can be achieved by means of digital methods of sound processing. A group of 35 Czech students of the Pedagogical Faculty of Palacky University was tested and a record of whispered vowels was taken from each of them. The record was digitalized and processed by the Discrete Fourier Trasform. The result is the power spectrum of the individual vocals - the graphic output consists of a plot of the relative power of individual frequencies in the original sound. The values of the first two maxima which represent the first and the second formants were determined from the graph. The values were plotted on a formant chart. Altogether, 175 spectral analyses of individual vowels were performed. In the resulting power spectrum, the first and the second formant frequencies were identified. The first formant was plotted against the second one and pure vocal formant regions were identified. Frequency bands for the Czech vowel "a" were circumscribed between 850 and 1150 Hz for first formant (F1) and between 1200 and 2000 Hz for second formant (F2). Similarly, borders of frequency band for vowel "e" they were 700 and 950 Hz for F1 and 1700 and 3000 Hz for F2. For vowel "i" 300 and 450 Hz for F1 and 2000 and 3600 Hz for F2, for vowel "o" 600 and 800 Hz for F1 and 600 and 1400 Hz for F2, for vowel "u" 100 and 400 Hz for F1 and 400 and 1200 Hz for F2. At low frequencies it is feasible to invoke the source-filter model of voice production and associate vowel identity with frequencies of the first two formants in the voice spectrum. On the other hand, subject to intonation, singing or other forms of exposed voice (such as emotional speech, focused speech), the formant regions tend to spread. In spectral analysis other frequencies dominate, so specific formant frequency bands are not easily recognizable. Although the resulting formant map is not much different from the formant

  1. Investigating the Mass Segregation Process in Globular Clusters with Blue Straggler Stars: The Impact of Dark Remnants

    Science.gov (United States)

    Alessandrini, Emiliano; Lanzoni, Barbara; Ferraro, Francesco R.; Miocchi, Paolo; Vesperini, Enrico

    2016-12-01

    We present the results of a set of N-body simulations aimed at exploring how the process of mass segregation (as traced by the spatial distribution of blue straggler stars, BSSs) is affected by the presence of a population of heavy dark remnants (as neutron stars and black holes (BHs)). To this end, clusters characterized by different initial concentrations and different fractions of dark remnants have been modeled. We find that an increasing fraction of stellar-mass BHs significantly delay the mass segregation of BSSs and the visible stellar component. In order to trace the evolution of BSS segregation, we introduce a new parameter (A +), which can be easily measured when the cumulative radial distribution of these stars and a reference population are available. Our simulations show that A + might also be used as an approximate indicator of the time remaining to the core collapse of the visible component.

  2. Dynamics of Escherichia coli chromosome segregation during multifork replication.

    Science.gov (United States)

    Nielsen, Henrik J; Youngren, Brenda; Hansen, Flemming G; Austin, Stuart

    2007-12-01

    Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division, the chromosomes contain multiple replication forks and must be segregated while this complex pattern of replication is still ongoing. Here, we show that replication and segregation continue in step, starting at the origin and progressing to the replication terminus. Thus, early-replicated markers on the multiple-branched chromosomes continue to separate soon after replication to form separate protonucleoids, even though they are not segregated into different daughter cells until later generations. The segregation pattern follows the pattern of chromosome replication and does not follow the cell division cycle. No extensive cohesion of sister DNA regions was seen at any growth rate. We conclude that segregation is driven by the progression of the replication forks.

  3. Dynamics of Escherichia coli Chromosome Segregation during Multifork Replication▿

    Science.gov (United States)

    Nielsen, Henrik J.; Youngren, Brenda; Hansen, Flemming G.; Austin, Stuart

    2007-01-01

    Slowly growing Escherichia coli cells have a simple cell cycle, with replication and progressive segregation of the chromosome completed before cell division. In rapidly growing cells, initiation of replication occurs before the previous replication rounds are complete. At cell division, the chromosomes contain multiple replication forks and must be segregated while this complex pattern of replication is still ongoing. Here, we show that replication and segregation continue in step, starting at the origin and progressing to the replication terminus. Thus, early-replicated markers on the multiple-branched chromosomes continue to separate soon after replication to form separate protonucleoids, even though they are not segregated into different daughter cells until later generations. The segregation pattern follows the pattern of chromosome replication and does not follow the cell division cycle. No extensive cohesion of sister DNA regions was seen at any growth rate. We conclude that segregation is driven by the progression of the replication forks. PMID:17905986

  4. Segregation, choice based letting and social housing: How housing policy can affect the segregation process

    NARCIS (Netherlands)

    Van Ham, M.; Manley, D.

    2012-01-01

    In this chapter we investigate the process of ethnic minority segregation in English social housing. Successive governments have expressed a commitment to the con-tradictory aims of providing greater choice – through the introduction of choice based letting – for households accessing an increasingly

  5. Genetic mapping and quantitative trait loci analysis for disease resistance using F2 and F5 generation-based genetic maps derived from 'Tifrunner' x'GT-C20' in peanut

    Science.gov (United States)

    One mapping population derived from Tifrunner × GT-C20 has shown great potential in developing a high dense genetic map and identification of QTLs for important disease resistance, Tomato spotted wilt virus (TSWV) and leaf spot (LS). Both F2 and F5 generation-based genetic maps were constructed prev...

  6. RAPD markers for the identification of yield traits in tomatoes under heat stress via bulked segregant analysis.

    Science.gov (United States)

    Lin, Kuan-Hung; Lo, Hsiao-Feng; Lee, Shao-Pei; George Kuo, C; Chen, Jen-Tzu; Yeh, Wei-Lun

    2006-12-01

    Tomato production is limited to a large extent by climates with high temperatures. Yield-related traits in tomatoes are generally thought to be quantitative inherited traits that are significantly affected by variation in environmental factors. Breeding for heat tolerance is restricted due to the complexity of the traits. The objective of this study was to identify random amplified polymorphic DNA (RAPD) markers linked to heat-tolerance traits in tomatoes under heat stress. Forty-three F(7) recombinant inbred lines (RILs) derived from a wild cross between CL 5915 (heat-tolerant) and L4422 (heat-sensitive) were obtained and scored for flower number, fruit number, fruit set, fruit weight and yield under screen house conditions during the hot (summer) season of 2003. The distributions of average fruit weight, fruit number, fruit set and yield in the F(7) population were strongly skewed towards heat susceptibility, characteristic of L4422. Significant positive correlation was observed between fruit weight and yield, and between fruit number, fruit set and yield. However, the increase in yield and fruit set by selecting for large flower number may be fairly minor due to non-significant correlation between these traits. Selecting for flower number may not be a useful tool for improving yield under heat stress. A total of 200 RAPD primers were screened, among which 14 were identified as associated with heat-tolerance using bulk segregant analysis (BSA) based on the F(7) population grown in a heat-stressed environment. Some RAPD markers were unique to one specific trait, and others were linked to two traits. All markers for heat tolerance related traits had positive gene effects as a result of the contribution of the CL5915 gene that bolstered these traits. One hundred F(2) plants derived from the same parents (CL5915xL4422) were grown in the same location during the summer of 2004 to test for the stability and reliability of the 14 markers identified. Selection for the

  7. Growth Conditions Regulate the Requirements for Caulobacter Chromosome Segregation

    DEFF Research Database (Denmark)

    Shebelut, Conrad W.; Jensen, Rasmus Bugge; Gitai, Zemer

    2009-01-01

    Growth environments are important metabolic and developmental regulators. Here we demonstrate a growth environment-dependent effect on Caulobacter chromosome segregation of a small-molecule inhibitor of the MreB bacterial actin cytoskeleton. Our results also implicate ParAB as important segregation...... determinants, suggesting that multiple distinct mechanisms can mediate Caulobacter chromosome segregation and that their relative contributions can be environmentally regulated....

  8. Growth conditions regulate the requirements for Caulobacter chromosome segregation.

    Science.gov (United States)

    Shebelut, Conrad W; Jensen, Rasmus B; Gitai, Zemer

    2009-02-01

    Growth environments are important metabolic and developmental regulators. Here we demonstrate a growth environment-dependent effect on Caulobacter chromosome segregation of a small-molecule inhibitor of the MreB bacterial actin cytoskeleton. Our results also implicate ParAB as important segregation determinants, suggesting that multiple distinct mechanisms can mediate Caulobacter chromosome segregation and that their relative contributions can be environmentally regulated.

  9. Metal contamination budget at the river basin scale: an original Flux-Flow Analysis (F2A for the Seine River

    Directory of Open Access Journals (Sweden)

    L. Lestel

    2007-11-01

    Full Text Available Material flow analysis and environmental contamination analysis are merged into a Flux-Flow analysis (F2A as illustrated for the metal circulation in the Seine River catchment. F2A combines about 30 metal flows in the anthroposphere (14 million people and/or metal fluxes in the environment (atmosphere, soils, and aquatic system originating from two dozens of sources. The nature and quality of data is very heterogeneous going from downscaled national economic statistics to upscaled daily environmental surveys.

    A triple integration is performed: space integration over the catchment (65 000 km2, time integration for the 1950–2000 trend analysed at 5 year resolution, and a conceptual integration resulting in two F2A indicators.

    Despite the various data sources an average metal circulation is established for the 1994–2003 period and illustrated for zinc: (i metal circulation in the anthroposphere is now two orders of magnitude higher than river outputs, (ii long term metal storage, and their potential leaks, in soils, wastedumps and structures is also orders of magnitude higher than present river fluxes. Trend analysis is made through two F2A indicators, the per capita excess load at the river outlet and the leakage ratio (excess fluxes/metal demand. From 1950 to 2000, they both show a ten fold improvement of metal recycling while the metal demand has increased by 2.5 to 5 for Cd, Cu, Cr, Pb and Zn, and the population by 50%.

  10. Highly Nonlinear Ising Model and Social Segregation

    CERN Document Server

    Sumour, M A; Shabat, M M

    2011-01-01

    The usual interaction energy of the random field Ising model in statistical physics is modified by complementing the random field by added to the energy of the usual Ising model a nonlinear term S^n were S is the sum of the neighbor spins, and n=0,1,3,5,7,9,11. Within the Schelling model of urban segregation, this modification corresponds to housing prices depending on the immediate neighborhood. Simulations at different temperatures, lattice size, magnetic field, number of neighbors and different time intervals showed that results for all n are similar, expect for n=3 in violation of the universality principle and the law of corresponding states. In order to find the critical temperatures, for large n we no longer start with all spins parallel but instead with a random configuration, in order to facilitate spin flips. However, in all cases we have a Curie temperature with phase separation or long-range segregation only below this Curie temperature, and it is approximated by a simple formula: Tc is proportion...

  11. Theta oscillations accompanying concurrent auditory stream segregation.

    Science.gov (United States)

    Tóth, Brigitta; Kocsis, Zsuzsanna; Urbán, Gábor; Winkler, István

    2016-08-01

    The ability to isolate a single sound source among concurrent sources is crucial for veridical auditory perception. The present study investigated the event-related oscillations evoked by complex tones, which could be perceived as a single sound and tonal complexes with cues promoting the perception of two concurrent sounds by inharmonicity, onset asynchrony, and/or perceived source location difference of the components tones. In separate task conditions, participants performed a visual change detection task (visual control), watched a silent movie (passive listening) or reported for each tone whether they perceived one or two concurrent sounds (active listening). In two time windows, the amplitude of theta oscillation was modulated by the presence vs. absence of the cues: 60-350ms/6-8Hz (early) and 350-450ms/4-8Hz (late). The early response appeared both in the passive and the active listening conditions; it did not closely match the task performance; and it had a fronto-central scalp distribution. The late response was only elicited in the active listening condition; it closely matched the task performance; and it had a centro-parietal scalp distribution. The neural processes reflected by these responses are probably involved in the processing of concurrent sound segregation cues, in sound categorization, and response preparation and monitoring. The current results are compatible with the notion that theta oscillations mediate some of the processes involved in concurrent sound segregation.

  12. Requirements for the evaluation of computational speech segregation systems.

    Science.gov (United States)

    May, Tobias; Dau, Torsten

    2014-12-01

    Recent studies on computational speech segregation reported improved speech intelligibility in noise when estimating and applying an ideal binary mask with supervised learning algorithms. However, an important requirement for such systems in technical applications is their robustness to acoustic conditions not considered during training. This study demonstrates that the spectro-temporal noise variations that occur during training and testing determine the achievable segregation performance. In particular, such variations strongly affect the identification of acoustical features in the system associated with perceptual attributes in speech segregation. The results could help establish a framework for a systematic evaluation of future segregation systems.

  13. Requirements for the evaluation of computational speech segregation systems

    DEFF Research Database (Denmark)

    May, Tobias; Dau, Torsten

    2014-01-01

    Recent studies on computational speech segregation reported improved speech intelligibility in noise when estimating and applying an ideal binary mask with supervised learning algorithms. However, an important requirement for such systems in technical applications is their robustness to acoustic...... conditions not considered during training. This study demonstrates that the spectro-temporal noise variations that occur during training and testing determine the achievable segregation performance. In particular, such variations strongly affect the identification of acoustical features in the system...... associated with perceptual attributes in speech segregation. The results could help establish a framework for a systematic evaluation of future segregation systems....

  14. Modelling density segregation in flowing bidisperse granular materials

    Science.gov (United States)

    Xiao, Hongyi; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

    2016-07-01

    Preventing segregation in flowing granular mixtures is an ongoing challenge for industrial processes that involve the handling of bulk solids. A recent continuum-based modelling approach accurately predicts spatial concentration fields in a variety of flow geometries for mixtures varying in particle size. This approach captures the interplay between advection, diffusion and segregation using kinematic information obtained from experiments and/or discrete element method (DEM) simulations combined with an empirically determined relation for the segregation velocity. Here, we extend the model to include density-driven segregation, thereby validating the approach for the two important cases of practical interest. DEM simulations of density bidisperse flows of mono-sized particles in a quasi-two-dimensional-bounded heap were performed to determine the dependence of the density-driven segregation velocity on local shear rate and particle concentration. The model yields theoretical predictions of segregation patterns that quantitatively match the DEM simulations over a range of density ratios and flow rates. Matching experiments reproduce the segregation patterns and quantitative segregation profiles obtained in both the simulations and the model, thereby demonstrating that the modelling approach captures the essential physics of density-driven segregation in granular heap flow.

  15. Gas phase UV and IR absorption spectra of CxF2x+1CHO (x=1-4)

    DEFF Research Database (Denmark)

    Hashikawa, Y; Kawasaki, M; Waterland, RL

    2004-01-01

    The UV and IR spectra of CxF2x+1 CHO (x = 1-4) were investigated using computational and experimental techniques. CxF2x+1CHO (x = 1-4) have broad UV absorption features centered at 300-310 nm. The maximum absorption cross-section increases significantly and shifts slightly to the red with increas...

  16. A Theoretical Framework for Association Studies in F2 Family Pools Using Allele Frequencies from Genotyping-By-Sequencing

    DEFF Research Database (Denmark)

    Janss, Luc L; Ashraf, Bilal H; Greve-Pedersen, Morten

    a sequencing approach to obtain Single Nucleotide Polymorphisms (SNPs) frequencies is considered here. In this work we develop the theoretical framework to perform association studies using allele frequencies from such F2 family pools. We show that expected allele frequencies in the F2 families will have...

  17. Prefrontal and agranular cingulate projections to the dorsal premotor areas F2 and F7 in the macaque monkey.

    Science.gov (United States)

    Luppino, Giuseppe; Rozzi, Stefano; Calzavara, Roberta; Matelli, Massimo

    2003-02-01

    The superior sector of Brodmann area 6 (dorsal premotor cortex, PMd) of the macaque monkey consists of a rostral and a caudal architectonic area referred to as F7 and F2, respectively. The aim of this study was to define the origin of prefrontal and agranular cingulate afferents to F7 and F2, in the light of functional and hodological evidence showing that these areas do not appear to be functionally homogeneous. Different sectors of F7 and F2 were injected with neural tracers in seven monkeys and the retrograde labelling was qualitatively and quantitatively analysed. The dorsorostral part of F7 (supplementary eye field, F7-SEF) was found to be a target of strong afferents from the frontal eye field (FEF), from the dorsolateral prefrontal regions located dorsally (DLPFd) and ventrally (DLPFv) to the principal sulcus and from cingulate areas 24a, 24b and 24c. In contrast, the remaining part of F7 (F7-non SEF) is only a target of the strong afferents from DLPFd. Finally, the ventrorostral part of F2 (F2vr), but not the F2 sector located around the superior precentral dimple (F2d), receives a minor, but significant, input from DLPFd and a relatively strong input from the cingulate gyrus (areas 24a and 24b) and area 24d. Present data provide strong hodological support in favour of the idea that areas F7 and F2 are formed by two functionally distinct sectors.

  18. Effect of preionization, fluorine concentration, and current density on the discharge uniformity in F2 excimer laser gas mixtures

    NARCIS (Netherlands)

    Mathew, D.; Bastiaens, Hubertus M.J.; Boller, Klaus J.; Peters, P.J.M.

    2007-01-01

    The discharge homogeneity in F2-based excimer laser gas mixtures and its dependence on various key parameters, such as the degree of preionization, preionization delay time, F2 concentration and current density, is investigated in a small x-ray preionized discharge chamber. The spatial and temporal

  19. 用于ArF准分子激光器的CaF2衬底性能的实验表征%Characterization of CaF2 Substrates for ArF Excimer Laser

    Institute of Scientific and Technical Information of China (English)

    邓文渊; 金春水; 靳京城

    2011-01-01

    Experimental characterizations of the CaF2 substrates for applications of ArF excimer lasers are performed. The measured absorption for an excimer-grade CaF2 substrate with 5 mm thickness is equal to 922 X 10~6. The root-mean-square (RMS) surface ronghness measured by atomic force microscope (AFM) and white light interferometer (WLI) are 0.22 and 1.24 nm, respectively, and the corresponding calculated surface scattering losses areO.005% andO.25%, respectively. The emission of impurity of Ce3+ and Eu3"1" ions in the ultraviolet (UV)-grade CaF2 substrates is detected and ascertained by fluorescence. No water molecular or other contamination on the surface of CaF2 is detected in Fourier transform infrared (FTIR) and Raman spectroscopy. The experimental results prove that laser calorimeters are suited to precisely measure the weak absorption of excimer-grade CaF2 substrates; the power spectral densities (PSDs) obtained by different measuring methods should be compared with each other and combined with the practical scattering losses to appropriately evaluate the surface roughness of CaF2 substrates; spectroscopy methods, such as fluorescence, FTIR and Raman spectroscopy, can effectively detect the trace impurities or defects in the CaF2 crystal and the contaminations on the surface of the polished CaF2 substrates.%对用于ArF准分子激光器的CaF2衬底进行了表征实验研究.采用分光光度计测量了CaF2衬底的透射光谱和反射光谱,利用激光量热法测量了CaF2衬底吸收,分别利用原子力显微镜(AFM)和白光干涉仪(WLI)测量了CaF2衬底的表面粗糙度,并计算了功率谱密度(PSD)和表面散射,最后分别测量了CaF2衬底的荧光光谱、红外光谱和拉曼光谱.激光量热法测量5 mm厚准分子级CaF2衬底的吸收结果为922×10-6.AFM和WLI测得的CaF2衬底表面粗糙度均方根值分别为0.22和1.24 nm,计算表面散射损耗分别为0.005%和0.25%.荧光光谱在紫外(UV)级CaF2

  20. On the mechanism of the post-midnight winter NmF2 enhancements: dependence on solar activity

    Directory of Open Access Journals (Sweden)

    T. Y. Leschinskaya

    Full Text Available The mechanism of the NmF2 peak formation at different levels of solar activity is analyzed using Millstone Hill IS radar observations. The hmF2 nighttime increase due to thermospheric winds and the downward plasmaspheric fluxes are the key processes responsible for the NmF2 peak formation. The electron temperature follows with the opposite sign the electron density variations in this process. This mechanism provides a consistency with the Millstone Hill observations on the set of main parameters. The observed decrease of the nighttime NmF2 peak amplitude with solar activity is due to faster increasing of the recombination efficiency compared to the plasmaspheric flux increase. The E×B plasma drifts are shown to be inefficient for the NmF2 nighttime peak formation at high solar activity.Key words: Ionosphere (ionosphere-atmosphere interactions; mid-latitude ionosphere; plasma temperature and density